WorldWideScience

Sample records for reinforced natural rubber

  1. Particle reinforced composites from acrylamide modified blend of styrene-butadiene and natural rubber

    Science.gov (United States)

    Blends of styrene-butadiene rubber and natural rubber that provide balanced properties were modified with acrylamide and reinforced with soy protein particles. The rubber composites show improved mechanical properties. Both modified rubber and composites showed a faster curing rate. The crosslinking...

  2. Nano-reinforcement of tire rubbers: silica-technology for natural rubber : exploring the infuence of non-rubber constituents on the natural rubber-silica system

    NARCIS (Netherlands)

    Sarkawi, S.S.

    2013-01-01

    Natural rubber is a renewable resource material with outstanding properties which offers significant advantages over its counterparts, the fossil-resource synthetic rubbers. In fact, a natural rubber tree is an efficient carbon dioxide sequester. Since natural rubber is a natural product, it is

  3. Reinforcing Natural Rubber with Cellulose Nanofibrils Extracted from Bleached Eucalyptus Kraft Pulp

    Science.gov (United States)

    Chunmei Zhang; Tianliang Zhai; Ronald Sabo; Craig Clemons; Yi Dan; Lih-Sheng Turng

    2014-01-01

    Reinforced natural rubber (NR) nanocomposites were prepared by solution mixing, casting, and evaporation of pre-vulcanized natural rubber latex and an aqueous suspension of cellulose nanofibrils (CNFs) extracted from bleached eucalyptus kraft pulp. Scanning electron microscopy (SEM) images showed that there were no micro-scaled aggregates observed in the nanocomposites...

  4. Viscoelastic and thermal properties of woven sisal fabric reinforced natural rubber biocomposites

    CSIR Research Space (South Africa)

    John, MJ

    2009-01-01

    Full Text Available This study explores the dynamic mechanical behavior of woven sisal fabric reinforced natural rubber composites. The influence of chemical modification on the viscoelastic properties has also been determined. Moreover, the effect of frequency...

  5. Silane grafted natural rubber and its compatibilization effect on silica-reinforced rubber tire compounds

    NARCIS (Netherlands)

    Sengloyluan, K.; Sahakaro, K.; Dierkes, W. K.; Noordermeer, J. W.M.

    2017-01-01

    Natural Rubber (NR) grafted with 3-octanoylthio-1-propyltriethoxysilane (NXT) was prepared by melt mixing using 1,1′-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane as initiator at 140 °C with NXT contents of 10 and 20 parts per hundred rubber [phr] and initiator 0.1 phr. The silane grafted on NR

  6. Effects of Thermal and Humidity Aging on the Interfacial Adhesion of Polyketone Fiber Reinforced Natural Rubber Composites

    OpenAIRE

    Lee, Han Ki; Kim, Dae Sik; Won, Jong Sung; Jin, Da Young; Lee, Hyun Jae; Lee, Seung Goo

    2016-01-01

    Polyketone fiber is considered as a reinforcement of the mechanical rubber goods (MRG) such as tires, automobile hoses, and belts because of its high strength and modulus. In order to apply it to those purposes, the high adhesion of fiber/rubber interface and good sustainability to aging conditions are very important. In this study, polyketone fiber reinforced natural rubber composites were prepared and they were subjected to thermal and humidity aging, to assess the changes of the interfacia...

  7. High performance natural rubber composites with a hierarchical reinforcement structure of carbon nanotube modified natural fibers

    International Nuclear Information System (INIS)

    Tzounis, Lazaros; Debnath, Subhas; Rooj, Sandip; Fischer, Dieter; Mäder, Edith; Das, Amit; Stamm, Manfred; Heinrich, Gert

    2014-01-01

    A simple and facile method for depositing multiwall carbon nanotubes (MWCNTs) onto the surface of naturally occurring short jute fibers (JFs) is reported. Hierarchical multi-scale structures were formed with CNT-networks uniformly distributed and fully covering the JFs (JF–CNT), as depicted by the scanning electron microscopy (SEM) micrographs. The impact of these hybrid fillers on the mechanical properties of a natural rubber (NR) matrix was systematically investigated. Pristine JFs were cut initially to an average length of 2.0 mm and exposed to an alkali treatment (a-JFs) to remove impurities existing in the raw jute. MWCNTs were treated under mild acidic conditions to generate carboxylic acid moieties. Afterward, MWCNTs were dispersed in an aqueous media and short a-JFs were allowed to react with them. Raman spectroscopy confirmed the chemical interaction between CNTs and JFs. The JF–CNT exposed quite hydrophobic behavior as revealed by the water contact angle measurements, improving the wettability of the non-polar NR. Consequently, the composite interfacial adhesion strength was significantly enhanced while a micro-scale “mechanical interlocking” mechanism was observed from the interphase-section transmission electron microscopy (TEM) images. SEM analysis of the composite fracture surfaces demonstrated the interfacial strength of NR/a-JF and NR/JF–CNT composites, at different fiber loadings. It can be presumed that the CNT-coating effectively compatibillized the composite structure acting as a macromolecular coupling agent. A detailed analysis of stress-strain and dynamic mechanical spectra confirmed the high mechanical performance of the hierarchical composites, consisting mainly of materials arising from natural resources. - Highlights: • Natural rubber (NR) composites reinforced with CNT-modified short jute fibers. • MWCNTs deposited to the surface of jute fibers via non-covalent interactions. • Hierarchical reinforcement structure with

  8. Silane grafted natural rubber and its compatibilization effect on silica-reinforced rubber tire compounds

    Directory of Open Access Journals (Sweden)

    K. Sengloyluan

    2017-12-01

    Full Text Available Natural Rubber (NR grafted with 3-octanoylthio-1-propyltriethoxysilane (NXT was prepared by melt mixing using 1,1′-di(tert-butylperoxy-3,3,5-trimethylcyclohexane as initiator at 140 °C with NXT contents of 10 and 20 parts per hundred rubber [phr] and initiator 0.1 phr. The silane grafted on NR molecules was confirmed by Fourier transform infrared (FTIR, proton nuclear magnetic resonance (1H-NMR and scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM-EDX. Based on 1H-NMR, the use of 10 and 20 phr (parts per hundred resin of silane resulted in grafted NXT onto NR of 0.66 and 1.32 mol%, respectively, or a grafting efficiency of approx. 38%. The use of NXT-grafted NR as compatibilizer in silica-filled NR compounds, to give a total amount of NXT in both grafted and non-grafted forms in the range of 0.8–6.1 wt% relative to the silica, decreases the Mooney viscosity and Payne effect of the compounds, improves filler-rubber interaction, and significantly increases the tensile properties of the silica-filled NR-compounds compared to the non-compatibilized one. At the same silane-content, the use of silane-grafted NR gives slightly better properties than the straight use of the same silane. With sulfur compensation, the use of NXT-grafted-NR with about 6 wt% NXT relative to the silica gives technical properties that reach the levels obtained for straight use of bis-(3-triethoxysilyl-propyltetrasulfide (TESPT at 8.6 wt% relative to the silica.

  9. Improved natural rubber composites reinforced with a complex filler network of biobased nanoparticles and ionomer

    Science.gov (United States)

    Biobased rubber composites are renewable and sustainable. Significant improvement in modulus of rubber composite reinforced with hydrophilic filler was achieved with the inclusion of ionomers. Soy particles aided with ionomer, carboxylated styrene-butadiene (CSB), formed a strong complex filler netw...

  10. Reinforcement of natural rubber/high density polyethylene blends with electron beam irradiated liquid natural rubber-coated rice husk

    Energy Technology Data Exchange (ETDEWEB)

    Chong, E.L.; Ahmad, Ishak [Polymer Research Center (PORCE), School of Chemical Science and Food Technology, Universiti Kebangsaan Malaysia 4, 43600 UKM Bangi, Selangor Darul Ehsan (Malaysia); Dahlan, H.M. [Radiation Processing Technology Division, Malaysian Nuclear Agency (Nuclear Malaysia), Bangi, 43000 Kajang, Selangor Darul Ehsan (Malaysia); Abdullah, Ibrahim, E-mail: dia@ukm.m [Polymer Research Center (PORCE), School of Chemical Science and Food Technology, Universiti Kebangsaan Malaysia 4, 43600 UKM Bangi, Selangor Darul Ehsan (Malaysia)

    2010-08-15

    Coating of rice husk (RH) surface with liquid natural rubber (LNR) and exposure to electron beam irradiation in air were studied. FTIR analysis on the LNR-coated RH (RHR) exposed to electron beam (EB) showed a decrease in the double bonds and an increase in hydroxyl and hydrogen bonded carbonyl groups arising from the chemical interaction between the active groups on RH surface with LNR. The scanning electron micrograph showed that the LNR formed a coating on the RH particles which transformed to a fine and clear fibrous layer at 20 kGy irradiation. The LNR film appeared as patches at 50 kGy irradiation due to degradation of rubber. Composites of natural rubber (NR)/high density polyethylene (HDPE)/RHR showed an optimum at 20-30 kGy dosage with the maximum stress, tensile modulus and impact strength of 6.5, 79 and 13.2 kJ/m{sup 2}, respectively. The interfacial interaction between the modified RH and TPNR matrix had improved on exposure of RHR to e-beam at 20-30 kGy dosage.

  11. Development and Characterization of Polymer Eco-Composites Based on Natural Rubber Reinforced with Natural Fibers.

    Science.gov (United States)

    Stelescu, Maria-Daniela; Manaila, Elena; Craciun, Gabriela; Chirila, Corina

    2017-07-11

    Natural rubber composites filled with short natural fibers (flax and sawdust) were prepared by blending procedure and the elastomer cross-linking was carried out using benzoyl peroxide. The microbial degradation of composites was carried out by incubating with Aspergillus niger recognized for the ability to grow and degrade a broad range of substrates. The extent of biodegradation was evaluated by weight loss and cross-linking degree study of composites after 2 months incubation in pure shake culture conditions. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR) have proved to be precious and valuable instruments for morphological as well as structural characterization of the composites before and after incubation with Aspergillus niger .

  12. Development and Characterization of Polymer Eco-Composites Based on Natural Rubber Reinforced with Natural Fibers

    Directory of Open Access Journals (Sweden)

    Maria-Daniela Stelescu

    2017-07-01

    Full Text Available Natural rubber composites filled with short natural fibers (flax and sawdust were prepared by blending procedure and the elastomer cross-linking was carried out using benzoyl peroxide. The microbial degradation of composites was carried out by incubating with Aspergillus niger recognized for the ability to grow and degrade a broad range of substrates. The extent of biodegradation was evaluated by weight loss and cross-linking degree study of composites after 2 months incubation in pure shake culture conditions. Scanning electron microscopy (SEM and Fourier transform infrared spectroscopy (FT-IR have proved to be precious and valuable instruments for morphological as well as structural characterization of the composites before and after incubation with Aspergillus niger.

  13. Effects of Thermal and Humidity Aging on the Interfacial Adhesion of Polyketone Fiber Reinforced Natural Rubber Composites

    Directory of Open Access Journals (Sweden)

    Han Ki Lee

    2016-01-01

    Full Text Available Polyketone fiber is considered as a reinforcement of the mechanical rubber goods (MRG such as tires, automobile hoses, and belts because of its high strength and modulus. In order to apply it to those purposes, the high adhesion of fiber/rubber interface and good sustainability to aging conditions are very important. In this study, polyketone fiber reinforced natural rubber composites were prepared and they were subjected to thermal and humidity aging, to assess the changes of the interfacial adhesion and material properties. Also, the effect of adhesive primer treatment, based on the resorcinol formaldehyde resin and latex (RFL, of polyketone fiber for high interfacial adhesion was evaluated. Morphological and property changes of the rubber composites were analyzed by using various instrumental analyses. As a result, the rubber composite was aged largely by thermal aging at high temperature rather than humidity aging condition. Interfacial adhesion of the polyketone/NR composites was improved by the primer treatment and its effect was maintained in aging conditions.

  14. Vulcanization characteristics and dynamic mechanical behavior of natural rubber reinforced with silane modified silica.

    Science.gov (United States)

    Chonkaew, Wunpen; Minghvanish, Withawat; Kungliean, Ulchulee; Rochanawipart, Nutthaya; Brostow, Witold

    2011-03-01

    Two silane coupling agents were used for hydrolysis-condensation reaction modification of nanosilica surfaces. The surface characteristics were analyzed using Fourier transform infrared spectroscopy (FTIR). The vulcanization kinetics of natural rubber (NR) + silica composites was studied and compared to behavior of the neat NR using differential scanning calorimetry (DSC) in the dynamic scan mode. Dynamic mechanical analysis (DMA) was performed to evaluate the effects of the surface modification. Activation energy E(a) values for the reaction are obtained. The presence of silica, modified or otherwise, inhibits the vulcanization reaction of NR. The neat silica containing system has the lowest cure rate index and the highest activation energy for the vulcanization reaction. The coupling agent with longer chains causes more swelling and moves the glass transition temperature T(g) downwards. Below the glass transition region, silica causes a lowering of the dynamic storage modulus G', a result of hindering the cure reaction. Above the glass transition, silica-again modified or otherwise-provides the expected reinforcement effect.

  15. Styrene grafted natural rubber reinforced by in situ silica generated via sol–gel technique

    Energy Technology Data Exchange (ETDEWEB)

    Sittiphan, Torpong [Program of Petrochemistry and Polymer Sciences, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Prasassarakich, Pattarapan [Department of Chemical Technology, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Poompradub, Sirilux, E-mail: sirilux.p@chula.ac.th [Department of Chemical Technology, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand)

    2014-02-15

    Highlights: • Sol–gel reaction by NR latex was the absence of use of organic solvent and base catalyst. • Well dispersed in situ formed silica particles in the rubber matrix were obtained. • In situ silica was better to improve mechanical properties of rubber vulcanizates. -- Abstract: The filling of styrene graft natural rubber (ST-GNR) with in situ formed silica was performed using the sol–gel reaction via the latex solution method. The mechanical properties of ST-GNR/NR vulcanizate were improved when using the in situ formed silica to levels higher than those obtained with the commercial ex situ formed silica filled ST-GNR/NR vulcanizates at a comparable silica content of 12 parts by weight per hundred parts of rubber. Transmission electron microscopy analysis revealed that the in situ silica particles were small (∼40 nm diameter) and well dispersed, while the commercial silica particles were larger (∼60 nm diameter) and markedly agglomerated in the rubbery matrix. The mechanical properties of the composites prepared via both the solid rubber and latex solution methods were comparable.

  16. Curing kinetics and mechanical behavior of natural rubber reinforced with pretreated carbon nanotubes

    International Nuclear Information System (INIS)

    Sui, G.; Zhong, W.H.; Yang, X.P.; Yu, Y.H.

    2008-01-01

    To significantly improve the performance of rubber materials, fundamental studies on rubber nanocomposites are necessary. The curing kinetics and vulcanizate properties of carbon nanotubes (CNTs)/natural rubber (NR) nanocomposites were analyzed in this paper. The pretreatment of CNTs was carried out by acid bath followed by ball milling with HRH bonding systems in experiments. The CNT/NR nanocomposites were prepared through solvent mixing on the basis of pretreatment of CNTs. The surface characteristic of CNTs and physical interaction between CNTs and NR macromolecules were analyzed by Fourier transform infrared spectroscopy (FT-IR). The vulcanization kinetics of CNT/NR nanocomposites were studied contrasting with the neat NR. The quality of the NR vulcanizates was assessed through static and dynamic mechanical property tests and scanning electron microscope (SEM). Curing kinetic parameters of the neat NR and CNT/NR nanocomposites were obtained from experiments; the results indicated that the presence of CNTs affects the curing process of the NR, and additional heating is required to cure CNT/NR nanocomposites due to its higher active energy. The dispersion of pretreated CNTs in the rubber matrix and interfacial adhesion between them were obviously improved. The physical and mechanical properties of the CNT/NR nanocomposites showed considerable increases by incorporation of the pretreated CNTs compared to the neat NR and untreated CNTs-filled NR nanocomposites

  17. Curing kinetics and mechanical behavior of natural rubber reinforced with pretreated carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Sui, G. [Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, Beijing University of Chemical Technology, Beijing 100029 (China); Department of Mechanical Engineering and Applied Mechanics, North Dakota State University, Fargo, ND 58105 (United States); Zhong, W.H. [Department of Mechanical Engineering and Applied Mechanics, North Dakota State University, Fargo, ND 58105 (United States)], E-mail: Katie.Zhong@ndsu.edu; Yang, X.P.; Yu, Y.H. [Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, Beijing University of Chemical Technology, Beijing 100029 (China)

    2008-06-25

    To significantly improve the performance of rubber materials, fundamental studies on rubber nanocomposites are necessary. The curing kinetics and vulcanizate properties of carbon nanotubes (CNTs)/natural rubber (NR) nanocomposites were analyzed in this paper. The pretreatment of CNTs was carried out by acid bath followed by ball milling with HRH bonding systems in experiments. The CNT/NR nanocomposites were prepared through solvent mixing on the basis of pretreatment of CNTs. The surface characteristic of CNTs and physical interaction between CNTs and NR macromolecules were analyzed by Fourier transform infrared spectroscopy (FT-IR). The vulcanization kinetics of CNT/NR nanocomposites were studied contrasting with the neat NR. The quality of the NR vulcanizates was assessed through static and dynamic mechanical property tests and scanning electron microscope (SEM). Curing kinetic parameters of the neat NR and CNT/NR nanocomposites were obtained from experiments; the results indicated that the presence of CNTs affects the curing process of the NR, and additional heating is required to cure CNT/NR nanocomposites due to its higher active energy. The dispersion of pretreated CNTs in the rubber matrix and interfacial adhesion between them were obviously improved. The physical and mechanical properties of the CNT/NR nanocomposites showed considerable increases by incorporation of the pretreated CNTs compared to the neat NR and untreated CNTs-filled NR nanocomposites.

  18. Lignocellulosic fiber reinforced rubber composites

    CSIR Research Space (South Africa)

    Jacob John, Maya

    2009-04-01

    Full Text Available Natural Rubber (NR) is a naturally occurring elastomeric polymer of isoprene (2-methyl-1,3-butadiene). It can be extracted from latex of only one kind of tree, the Hevea braziliensis. Hevea rubber is produced in many tropical regions of Southeast...

  19. Evaluation of clay hybrid nanocomposites of different chain length as reinforcing agent for natural and synthetic rubbers

    International Nuclear Information System (INIS)

    Yehia, A.A.; Akelah, A.M.; Rehab, A.; El-Sabbagh, S.H.; El Nashar, D.E.; Koriem, A.A.

    2012-01-01

    Highlights: → The modified organo-clay (MMT-ATBN) markedly reinforce natural and synthetic rubbers. → The reinforcing efficiency of the organo-clay is much higher than HAF carbon black. → The reinforcing efficiency of MMT modified with different alkylamines greatly depend on the chain length. → The good compatibility of modified organo-clay with NBR can be attributed to the chemical nature. -- Abstract: Polymer nanocomposites are one of the highly discussed research topics in recent time. It has been reported in the present paper the preparation and the properties of different nanoclays based on sodium montmorillonite (bentonite) and some organic amines of varying chain lengths (dodecylamine, hexadecylamine and octadecylamine) beside amine-terminated butadiene-acrylonitrile copolymer (ATBN). The hybrid clays have been characterized with the help of Fourier Transform Infrared spectroscopy (FTIR). Transmission electron microscopy (TEM), Scanning electron microscopy (SEM), Wide angle X-ray diffractions (WXRD), and Thermogravimetric analysis (TGA). X-ray results showed that the intergallery distance of the clay is increased as a result of the intercalation of the amines and ATBN. The nanocomposite clays were incorporated in natural and synthetic rubbers (NR, SBR and NBR). The physico-mechanical properties are greatly improved with loading low concentrations of the nanocomposite clays compared with carbon black.

  20. Reinforcing effect of plasma modified halloysite nanotubes in a carbon black filled natural rubber-butadien rubber matrix

    NARCIS (Netherlands)

    Poikelispaa, Minna; Das, Amit; Dierkes, Wilma K.; Vuorinen, Jyrki

    2011-01-01

    Rubber composites are generally produced by the direct incorporation of fillers like carbon black and/or silica into the rubber matrix. The incorporation of different types of nanofillers is the subject of recent research with the aim of preparing composites with special compositions and properties.

  1. Natural rubber: leather composites

    OpenAIRE

    Ravichandran,K.; Natchimuthu,N.

    2005-01-01

    Leather is a fibrous protein consisting of collagen in a three dimensionally crosslinked network. Chrome tanning of leather improves the appearance of leather but at the same time emits both solid and liquid chrome leather wastes. Scrap rubber recycling using untreated and neutralized leather fibrous particles in natural rubber has been studied. Vulcanization, mechanical, morphological and swelling properties of the natural rubber - scrap rubber composites containing neutralized leather have ...

  2. Preparation and properties of natural rubber reinforced with polydopamine-coating modified carbon nanotubes

    Directory of Open Access Journals (Sweden)

    Y-L. Lu

    2017-01-01

    Full Text Available Multi-walled carbon nanotubes (MWCNTs were functionalized by polydopamine (PDA-coating and mixed with natural rubber (NR via latex compounding. Compared with pristine MWCNTs, the surface of MWCNT-PDA was covered by an amorphous and nanometer-scale PDA layer which had a large amount of oxygenic and nitric functional groups. So the MWCNT-PDA showed a perfect dispersion in NR matrix. The tensile strength of NR/MWCNT-PDA (5 phr composites is 28.6 MPa, compared with the pure NR, which increased by 42%. For the electrical properties, when the content of MWCNTPDA or MWCNTs is 2 phr, the volume resistivity of NR/MWCNT-PDA composites falls to about 2.7·109 Ω·cm, compared with 3.3·1013 Ω·cm of NR/MWCNT composites. The thermal conductivity of NR composites increased only by 28.2% when 5 phr MWCNT-PDA was added. A model proposed by Nan was used to calculate the thermal conductivity of NR/MWCNT composites, and the calculated values were compared with the experimental values, the results showed that the interface thermal resistance is the main reason why MWCNTs could not significantly increase the thermal conductivity of natural rubber.

  3. Mechanical and thermal properties of short-coirfiber-reinforced natural rubber/polyethylene composites

    Science.gov (United States)

    Xu, Zh. H.; Kong, Zh. N.

    2014-07-01

    Natural rubber (NR) and polyethylene (PE) composites were compounded with chemically treated coir fibers by using a heated two-roll mill. Two chemical treatments of the fibers — by silane and sodium hydroxide — were carried out to improve the interfacial adhesion between them and the polyethylene matrix. The mechanical properties of the composites obtained were evaluated and compared with those made from a neat polymer and untreated fibers. The mechanical properties of the composites, such as the tensile strength, Young's modulus, and the elongation at break, were examined, and their shrinkage and flame retardant characteristics were measured. From these experiments, the effect of plasma treatment on the mechanical-physical behavior of coconut-fiberreinforced NR/PE composites was identified. In addition, their thermal characteristics were evaluated, and the results showed a slight decrease in them with increasing content of coir fibers.

  4. Natural rubber: leather composites

    Directory of Open Access Journals (Sweden)

    K. Ravichandran

    2005-06-01

    Full Text Available Leather is a fibrous protein consisting of collagen in a three dimensionally crosslinked network. Chrome tanning of leather improves the appearance of leather but at the same time emits both solid and liquid chrome leather wastes. Scrap rubber recycling using untreated and neutralized leather fibrous particles in natural rubber has been studied. Vulcanization, mechanical, morphological and swelling properties of the natural rubber - scrap rubber composites containing neutralized leather have been discussed. Use of chrome leather particles has been found to improve the consumption of scrap rubber powder in natural rubber formulations. Polymer composites based on leather wastes as fillers are reported to be useful for many applications such as in construction materials, automobile interior moldings, heat and sound insulating boards, shoe soles, flooring materials and moldings with good anti-static properties, air permeability and good appearances.

  5. Reinforcement of Natural Rubber with Core-Shell Structure Silica-Poly(Methyl Methacrylate Nanoparticles

    Directory of Open Access Journals (Sweden)

    Qinghuang Wang

    2012-01-01

    Full Text Available A highly performing natural rubber/silica (NR/SiO2 nanocomposite with a SiO2 loading of 2 wt% was prepared by combining similar dissolve mutually theory with latex compounding techniques. Before polymerization, double bonds were introduced onto the surface of the SiO2 particles with the silane-coupling agent. The core-shell structure silica-poly(methyl methacrylate, SiO2-PMMA, nanoparticles were formed by grafting polymerization of MMA on the surface of the modified SiO2 particles via in situ emulsion, and then NR/SiO2 nanocomposite was prepared by blending SiO2-PMMA and PMMA-modified NR (NR-PMMA. The Fourier transform infrared spectroscopy results show that PMMA has been successfully introduced onto the surface of SiO2, which can be well dispersed in NR matrix and present good interfacial adhesion with NR phase. Compared with those of pure NR, the thermal resistance and tensile properties of NR/SiO2 nanocomposite are significantly improved.

  6. Performance of carbon fiber reinforced rubber composite armour against shaped charge jet penetration

    OpenAIRE

    Yue Lian-yong; Li Wei; Zu Xu-dong; Huang Zheng-xiang; Gao Zhen-yu

    2016-01-01

    Natural rubber is reinforced with carbon fiber; the protective performances of the carbonfiber reinforced rubber composite armour to shaped charge jet have been studied based on the depth of penetration experiments. The craters on the witness blocks, the nature rubber based composite plates’ deformation and the Scanning Electron Microscopy for the hybrid fiber reinforced rubber plate also is analyzed. The results showed that the composite armour can affect the stability of the jet and made pa...

  7. Reinforcement of natural rubber hybrid composites based on marble sludge/Silica and marble sludge/rice husk derived silica

    Directory of Open Access Journals (Sweden)

    Khalil Ahmed

    2014-03-01

    Full Text Available A research has been carried out to develop natural rubber (NR hybrid composites reinforced with marble sludge (MS/Silica and MS/rice husk derived silica (RHS. The primary aim of this development is to scrutinize the cure characteristics, mechanical and swelling properties of such hybrid composite. The use of both industrial and agricultural waste such as marble sludge and rice husk derived silica has the primary advantage of being eco-friendly, low cost and easily available as compared to other expensive fillers. The results from this study showed that the performance of NR hybrid composites with MS/Silica and MS/RHS as fillers is extremely better in mechanical and swelling properties as compared with the case where MS used as single filler. The study suggests that the use of recently developed silica and marble sludge as industrial and agricultural waste is accomplished to provide a probable cost effective, industrially prospective, and attractive replacement to the in general purpose used fillers like china clay, calcium carbonate, and talc.

  8. Comparative studies on the mechanical properties of natural rubber and natural rubber filled with multi-walled carbon nanotubes

    Science.gov (United States)

    Ismail, R.; Ibrahim, A.; Rusop, M.; Adnan, A.

    2018-05-01

    The present article compares the mechanical properties of natural rubber (NR) and carbon nanotubes (CNTs) filled natural rubber composites. Four types of nanocomposite specimens are fabricated with different MWCNT loadings: 0 wt% (pure natural rubber), 1 wt%, 3 wt%, and 5 wt%. The specimens are tested for their mechanical properties. It is observed that the tensile strength, hardness and elongation break of CNTs filled rubber composites are remarkably higher than that of raw rubber indicating the inherent reinforcing potential of CNTs. Percentage of the elongation at break of rubber CNTs composites is lower than that of raw rubber.

  9. A Review on Reinforcement of Natural Rubber by Silica Fillers for Use in Low-Rolling Resistance Tires

    NARCIS (Netherlands)

    Sarkawi, S.S.; Kaewsakul, Wisut; Sahakaro, Kannika; Dierkes, Wilma K.; Noordermeer, Jacobus W.M.

    2015-01-01

    High dispersion silica has recently become the preferred alternative to carbon black for low rolling resistance tyres. However, the combination of natural rubber with silica and a coupling agent remains a challenge, but also offers a tremendous potential for reduction of energy consumption of

  10. Performance of carbon fiber reinforced rubber composite armour against shaped charge jet penetration

    Directory of Open Access Journals (Sweden)

    Yue Lian-yong

    2016-01-01

    Full Text Available Natural rubber is reinforced with carbon fiber; the protective performances of the carbonfiber reinforced rubber composite armour to shaped charge jet have been studied based on the depth of penetration experiments. The craters on the witness blocks, the nature rubber based composite plates’ deformation and the Scanning Electron Microscopy for the hybrid fiber reinforced rubber plate also is analyzed. The results showed that the composite armour can affect the stability of the jet and made part of the jet fracture. The carbon fiber reinforced rubber composite armour has good defence ablity especially when the nature rubber plate hybrid 15% volume percentage carbonfiber and the obliquity angle is 68°. The hybrid fiber reinforced rubber composite armour can be used as a new kind of light protective armour.

  11. Reinforcement of tire tread and radiator hose rubbers with short aramid fibers

    OpenAIRE

    Shirazi, Morteza; Noordermeer, Jacobus W.M.

    2010-01-01

    Short fiber reinforced rubber composites have gained great importance due to their advantages in processing and low cost, coupled with high strength. Reinforcement with short fibers offers attractive features such as design flexibility, high modulus, tear strength, etc. The degree of reinforcement depends upon many parameters, such as: the nature of the rubber matrix, the type of fiber, the concentration and orientation of the fibers, fiber to rubber adhesion to generate a strong interface, f...

  12. Crack Velocities in Natural Rubber.

    Science.gov (United States)

    1982-05-01

    vulcanized natural rubber (3). The surprisingly low value for natural rubber was attributed to highly anisotropic elastic behavior at high strains...Dr. R.L. Rabie Hercules Incorporated WX-2, MS-952 Alleghany Ballistic Lab Los Alamos National Lab. P.O. Box 210 P.O. Box 1663 Washington, D.C. 21502

  13. Alternative sources of natural rubber

    NARCIS (Netherlands)

    Mooibroek, H.; Cornish, K.

    2000-01-01

    Rubber (cis-1,4-polyisoprene) is one of the most important polymers naturally produced by plants because it is a strategic raw material used in more than 40,000 products, including more than 400 medical devices. The sole commercial source, at present, is natural rubber harvested from the Brazilian

  14. PROPERTIES OF NR AND NR/ENR BASED RUBBER COMPOUNDS REINFORCED WITH CHOPPED AND SIZED CARBON FIBER

    Directory of Open Access Journals (Sweden)

    Bağdagül Karaağaç

    2016-12-01

    Full Text Available High elasticity, mechanical resistance and antivibration characteristics of natural rubber (NR are essential issue in the main area of vehicle tyres and high modulus demanding bearing applications. In this study, especially in bearing applications, where natural rubber modulus properties are limited, natural rubber has been reinforced with chopped and hydrocarbon sized carbon fiber to get improved tensile modulus. Besides, epoxidized natural rubber (ENR, which was produced by chemical modification of natural rubber, blended with NR and the compounds have been reinforced with epoxy sized carbon fiber. NR and NR/ENR based rubber compounds’ rheological, mechanical, and aging properties have been systematically investigated and evaluated.

  15. Alternative secondary accelerator for silica-filled natural rubber formulations

    NARCIS (Netherlands)

    Kaewsakul, Wisut; Sahakaro, Kannika; Dierkes, Wilma K.; Noordermeer, Jacobus W.M.

    2013-01-01

    Dithiophosphate (DTP) displays a good efficiency towards improved overall properties of silica-reinforced natural rubber compounds, when it is used as secondary accelerator in a sulfenamide primary accelerated sulfur vulcanization system. Comparing DTP with diphenylguanidine (DPG), DTP is more

  16. Carboxymethyl Cellulose From Kenaf Reinforced Composite Polymer Electrolytes Based 49 % Poly (Methyl Methacrylate)-Grafted Natural Rubber

    International Nuclear Information System (INIS)

    Serawati Jafirin; Ishak Ahmad; Azizan Ahmad; Ishak Ahmad; Azizan Ahmad

    2014-01-01

    Composite polymer electrolytes based 49 % poly(methyl methacrylate)-grafted natural rubber (MG49) incorporating lithium triflate (LiCF 3 SO 3 ) were prepared. The study mainly focuses on the ionic conductivity performances and mechanical properties. Prior to that, carboxymethyl cellulose was synthesized from kenaf fiber. The films were characterized by electrochemical impedance (EIS) spectroscopy, linear sweep voltammetry (LSV), universal testing machine and scanning electron microscopy (SEM). The conductivity was found to increase with carboxymethyl cellulose loading. The highest conductivity value achieved was 6.5 x 10 -6 Scm -1 upon addition of 6 wt % carboxymethyl cellulose. LSV graph shows the stability of this film was extended to 2.7 V at room temperature. The composition with 6 wt % carboxymethyl cellulose composition showed the highest tensile strength value of 7.9 MPa and 273 MPa of Young's modulus. The morphology of the electrolytes showed a smooth surface of films after addition of salt and filler indicating amorphous phase in electrolytes system. Excellent mechanical properties and good ionic conductivity are obtained, enlightening that the film is suitable for future applications as thin solid polymer electrolytes in lithium batteries. (author)

  17. The Cyclization of natural rubber

    International Nuclear Information System (INIS)

    Mirzataheri, M.

    2000-01-01

    The effect of solvent, temperature, time, weight percent of catalyst on the rate and mechanism of cyclization of natural rubber was studied in toluene and xylene solutions having tin tetra chloride catalyst (SnCl 4 ). Iodo metric titration show, with 8% SnCl 4 (based on polymer weight) cyclization occurs, leaving 27.4% of the total unsaturation. Infrared spectra of cyclized natural rubber show decreased absorption intensity at 840 and 780 cm -1 which are characteristic bands of the linear polymer and the appearance of absorption band at 890 cm -1 as cycles were formed. By using this chemical modification, natural rubber is transformed into a resinous thermoplastic, hard, non rubbery cyclized material with much less unsaturation than the original rubber, which could find commercial applications ad adhesives, printing inks, industrial and ship paints

  18. Antidegradation and reinforcement effects of phenyltrimethoxysilane- or N-[3-(trimethoxysilyl)propyl]aniline-modified silica particles in natural rubber composites

    Energy Technology Data Exchange (ETDEWEB)

    Tunlert, Apinya [Program in Petrochemistry and Polymer Science, Chulalongkorn University, Bangkok 10330 (Thailand); Prasassarakich, Pattarapan [Department of Chemical Technology, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Poompradub, Sirilux, E-mail: sirilux.p@chula.ac.th [Department of Chemical Technology, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Center for Petroleum, Petrochemical and Advanced Material, Chulalongkorn University Bangkok 10330 (Thailand)

    2016-04-15

    The modification of silica particles with phenyltrimethoxysilane or N-[3-(trimethoxysilyl)propyl]aniline via a sol–gel reaction was performed in order to improve the dispersion of silica and antidegradation in natural rubber (NR). The functional groups on the modified silica surface were characterized by Fourier transform infrared spectroscopy, while the morphology was evaluated by scanning and transmission electron microscopy. The surface properties and antioxidant activity of the modified silica particles were determined by the water contact angle and 2, 2-diphenyl-1-picrylhydrazyl assay, respectively. The modified silica particles exhibited a higher hydrophobicity and a decreased interfacial adhesion energy compared with the unmodified silica particles. The modified silica particles were then incorporated into NR. The better dispersion of the modified silica particles than the unmodified ones in the NR matrix resulted in improved mechanical properties in terms of the modulus at 300% elongation (2.9 ± 0.02 MPa), hardness (52.5 ± 0.2 Shore A), abrasion resistance (241 ± 8 mm{sup 3}) and compression set (20.2 ± 0.6%). In addition, the inclusion of the modified silica particles in the NR matrix gave a high initial temperature of decomposition and retarded the ozone-induced degradation compared with the NR filled with unmodified silica particles. - Highlights: • Silica was surface modified with PhTMS or ATMS via a sol–gel reaction. • Modified silica showed a decreased interfacial adhesion energy. • Modified silica showed an enhanced free radical scavenging activity. • Modified silica improved the mechanical properties, thermal stability and ozone resistance in NR vulcanizates.

  19. Cellulose nanocrystals reinforced foamed nitrile rubber nanocomposites.

    Science.gov (United States)

    Chen, Yukun; Zhang, Yuanbing; Xu, Chuanhui; Cao, Xiaodong

    2015-10-05

    Research on foamed nitrile rubber (NBR)/cellulose nanocrystals (CNs) nanocomposites is rarely found in the literatures. In this paper, CNs suspension and NBR latex was mixed to prepared the foamed NBR/CNs nanocomposites. We found that the CNs mainly located in the cell walls, effectively reinforcing the foamed NBR. The strong interaction between the CNs and NBR matrix restricted the mobility of NBR chains surrounding the CNs, hence increasing the crosslink density of the NBR matrix. CNs exhibited excellent reinforcement on the foamed NBR: a remarkable increase nearly 76% in the tensile strength of the foamed nanocomposites was achieved with a load of only 15 phr CNs. Enhanced mechanical properties make the foamed NBR/CNs nanocomposites a promising damping material for industrial applications with a potential to reduce the petroleum consumption. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Shear modulus and damping ratio of natural rubber containing carbon nanotubes

    Science.gov (United States)

    Ismail, R.; Ibrahim, A.; Rusop, M.; Adnan, A.

    2018-05-01

    This paper presents the results of an investigation into the potential application of Natural rubber (NR) containing Carbon Nanotubes (CNTs) by measuring its shear modulus and damping ratio. Four different types of rubber specimens which fabricated with different MWCNT loadings: 0 wt% (pure natural rubber), 1 wt%, 3 wt%, and 5 wt%. It is observed that the shear modulus and damping ratio of CNTs filled rubber composites are remarkably higher than that of raw rubber indicating the inherent reinforcing potential of CNTs.

  1. Electrospinning of PVC with natural rubber

    Science.gov (United States)

    Othman, Muhammad Hariz; Mohamed, Mahathir; Abdullah, Ibrahim

    2013-11-01

    Polyvinyl chloride (PVC) was mixed with natural rubbers which are liquid natural rubber (LNR), liquid epoxidised natural rubber (LENR) and liquid epoxidised natural rubber acrylate (LENRA) for a preparation of a fine non-woven fiber's mat. PVC and each natural rubbers(PVC:LENR, PVC:LNR and PVC:LENRA) were mixed based on ratio of 70:30. Electrospinning method was used to prepare the fiber. The results show that the spinnable concentration of PVC/ natural rubber/THF solution is 16 wt%. The morphology, diameter, structure and degradation temperature of electrospun fibers were investigated by scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). SEM photos showed that the morphology and diameter of the fibers were mainly affected by the addition of natural rubber. TGA results suggested that PVC electrospun fiber has higher degradation temperature than those electrospun fibers that contain natural rubber.

  2. Electrospinning of PVC with natural rubber

    International Nuclear Information System (INIS)

    Othman, Muhammad Hariz; Abdullah, Ibrahim; Mohamed, Mahathir

    2013-01-01

    Polyvinyl chloride (PVC) was mixed with natural rubbers which are liquid natural rubber (LNR), liquid epoxidised natural rubber (LENR) and liquid epoxidised natural rubber acrylate (LENRA) for a preparation of a fine non-woven fiber’s mat. PVC and each natural rubbers(PVC:LENR, PVC:LNR and PVC:LENRA) were mixed based on ratio of 70:30. Electrospinning method was used to prepare the fiber. The results show that the spinnable concentration of PVC/ natural rubber/THF solution is 16 wt%. The morphology, diameter, structure and degradation temperature of electrospun fibers were investigated by scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). SEM photos showed that the morphology and diameter of the fibers were mainly affected by the addition of natural rubber. TGA results suggested that PVC electrospun fiber has higher degradation temperature than those electrospun fibers that contain natural rubber

  3. Electrospinning of PVC with natural rubber

    Energy Technology Data Exchange (ETDEWEB)

    Othman, Muhammad Hariz; Abdullah, Ibrahim [Department of Chemistry, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Mohamed, Mahathir [Radiation Processing Technology Division (BTS), Malaysian Nuclear Agency, Bangi, 43000, Kajang (Malaysia)

    2013-11-27

    Polyvinyl chloride (PVC) was mixed with natural rubbers which are liquid natural rubber (LNR), liquid epoxidised natural rubber (LENR) and liquid epoxidised natural rubber acrylate (LENRA) for a preparation of a fine non-woven fiber’s mat. PVC and each natural rubbers(PVC:LENR, PVC:LNR and PVC:LENRA) were mixed based on ratio of 70:30. Electrospinning method was used to prepare the fiber. The results show that the spinnable concentration of PVC/ natural rubber/THF solution is 16 wt%. The morphology, diameter, structure and degradation temperature of electrospun fibers were investigated by scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). SEM photos showed that the morphology and diameter of the fibers were mainly affected by the addition of natural rubber. TGA results suggested that PVC electrospun fiber has higher degradation temperature than those electrospun fibers that contain natural rubber.

  4. Mechanical and thermal properties of sisal fiber-reinforced rubber seed oil-based polyurethane composites

    International Nuclear Information System (INIS)

    Bakare, I.O.; Okieimen, F.E.; Pavithran, C.; Abdul Khalil, H.P.S.; Brahmakumar, M.

    2010-01-01

    The development of high-performance composite materials from locally sourced and renewable materials was investigated. Rubber seed oil polyurethane resin synthesized using rubber seed monoglyceride derived from glycerolysis of the oil was used as matrix in the composite samples. Rubber seed oil-based polyurethane composite reinforced with unidirectional sisal fibers were prepared and characterized. Results showed that the properties of unidirectional fiber-reinforced rubber seed oil-based polyurethane composites gave good thermal and mechanical properties. Also, the values of tensile strengths and flexural moduli of the polyurethane composites were more than tenfold and about twofold higher than un-reinforced rubber seed oil-based polyurethane. The improved thermal stability and the scanning electron micrographs of the fracture surface of the composites were attributed to good fiber-matrix interaction. These results indicate that high-performance 'all natural products' composite materials can be developed from resources that are readily available locally.

  5. Natural rubber producing plants: An overview | Venkatachalam ...

    African Journals Online (AJOL)

    ... Hevea and also other natural rubber producing species for alternative source of latex production in the near future. Keywords: Alternative rubber sources, biotechnology, breeding, Hevea brasiliensis, Parthenium argentatum, Taraxacum koksaghyz, Ficus bengalensis, Lactuca serriola. African Journal of Biotechnology Vol.

  6. Physico-mecha-nical properties of rubber seed shell carbon – filled natural rubber compounds

    Directory of Open Access Journals (Sweden)

    L.O. Ekebafe

    2010-07-01

    Full Text Available Samples of rubber seed shells were carbonized at varying temperatures (100, 200, 300, 400, 500, 600, 700 and 800 °C for three hours each and sieved through a 150 μm screen. The portion of the rubber seed shell carbon that passed through the screen was characterized in terms of loss on ignition, surface area, moisture content, pH, bulk density, and metal content and used in compounding natural rubber. The characterization shows that the pH, conductivity, loss on ignition and the surface area increases with the increases of the heating temperature, unlike the bulk density which decreases. The compound mixes were cured using the efficient vulcanization system. Cure characteristics of compounds and physico-mechanical properties of the vulcanisates were measured as a function of filler loading along with that of N330 carbon-black filled natural rubbers. The results showed that the cure times, scorch times and the torque gradually increased, with increasing the filler content for rubber seed shell carbon-filled natural rubber, with the filler obtained at carbonizing temperature of 600 °C tending to show optimum cure indices. The physicomechanical properties of the vulcanisates increase with filler loading. The reinforcing potential of the carbonized rubber seed shell carbon was found to increase markedly for the filler obtained at the temperature range of 500-600 °C and then decreases with further increase in temperature.

  7. Radiation induced graft copolymerization of acrylonitrile on natural rubber

    International Nuclear Information System (INIS)

    Claramma, N.M.; Mathew, N.M.; Thomas, E.V.

    1989-01-01

    Acrylonitrile graft natural rubber was prepared by initiating the polymerization of acrylonitrile in natural rubber field latex using γ-rays. The reaction was carried out at different rubber-monomer concentrations and the properties of the modified rubbers were compared with those of natural rubber and nitrile rubber. (author)

  8. Chemical modifications of liquid natural rubber

    Science.gov (United States)

    Azhar, Nur Hanis Adila; Rasid, Hamizah Md; Yusoff, Siti Fairus M.

    2016-11-01

    Liquid natural rubber (LNR) was synthesized via photosentisized degradation of natural rubber (NR). LNR was modified into epoxidized liquid natural rubber (LENR) and hydroxylated liquid natural rubber (LNR-OH) using Na2WO4/CH3COOH/H2O2 catalytic system. Chemical structures of LNR and modified LNRs were characterized using Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) and 1H Nuclear Magnetic Resonance (NMR) spectroscopies. Integration of 1H NMR was used to calculate the epoxy content (%) of LENR. 1H NMR detected the formation of LNR-OH after prolonged heating and increased of catalyst in oxidation reaction.

  9. Stimuli-responsive cement-reinforced rubber.

    Science.gov (United States)

    Musso, Simone; Robisson, Agathe; Maheshwar, Sudeep; Ulm, Franz-Josef

    2014-05-14

    In this work, we report the successful development of a cement-rubber reactive composite with reversible mechanical properties. Initially, the composite behaves like rubber containing inert filler, but when exposed to water, it increases in volume and reaches a stiffness that is intermediate between that of hydrogenated nitrile butadiene rubber (HNBR) and hydrated cement, while maintaining a relatively large ductility characteristic of rubber. After drying, the modulus increases even further up to 400 MPa. Wet/drying cycles prove that the elastic modulus can reversibly change between 150 and 400 MPa. Utilizing attenuated total reflection Fourier transform infrared spectroscopy), we demonstrate that the high pH produced by the hydration of cement triggers the hydrolysis of the rubber nitrile groups into carboxylate anions. Thus, the salt bridges, generated between the carboxylate anions of the elastomer and the cations of the filler, are responsible for the reversible variations in volume and elastic modulus of the composite as a consequence of environmental moisture exposure. These results reveal that cement nanoparticles can successfully be used to accomplish a twofold task: (a) achieve an original postpolymerization modification that allows one to work with carboxylate HNBR (HXNBR) not obtained by direct copolymerization of carboxylate monomers with butadiene, and (b) synthesize a stimuli-responsive polymeric composite. This new type of material, having an ideal behavior for sealing application, could be used as an alternative to cement for oil field zonal isolation applications.

  10. Natural rubber producing plants: An overview

    African Journals Online (AJOL)

    User

    2013-03-20

    Mar 20, 2013 ... Currently, Hevea brasiliensis has been only one resource for commercial natural rubber production. ...... ADVANTAGES AND DISADVANTAGES ... polymer chain. Combinations of an amine antioxidant and a zinc dialkyldithiocarbamate have been used to counter these effects, improving guayule rubber ...

  11. Preparation of Natural Rubber (NR) Based Nano-Sized Materials Using Sol-Gel Technique

    International Nuclear Information System (INIS)

    Dahlan Mohd; Mahathir Mohamed

    2011-01-01

    The objectives of this project are to prepare nano-sized natural rubber-based hybrid coating material by sol-gel technique; to explore the possibility of producing ENR-Si (epoxidized natural rubber-silica) cramer with toughening effects; and to use it in radiation curing of surface coating. Since early 1960s Malaysia has introduced various forms of value-added natural rubber such as Standard Malaysian Rubber (SMR), methylmethacrylate-grafted natural rubber (MG rubber), followed by liquid natural rubber and epoxidized natural rubber (ENR). Products such as liquid epoxidized natural rubber acrylate (LENRA) and thermoplastic natural rubber (TPNR) are still on-going research projects in Nuclear Malaysia. The former has strong possibility to be used as radiation-sensitive comparabilities in TPNR blends, besides its original purpose for example in radiation curing of surface coating. But earlier findings indicated that, to make it (as for surface coating) more effective, reinforcement system is needed to be introduced. Strong candidate is silica by sol-gel technique, since common reinforcement filler for example carbon black has drawbacks in this particular case. This technique was introduced in late 1960s to produce metal oxides such as silica and titanium oxides in solution. (author)

  12. Thermal properties of hydrogenated liquid natural rubber

    Science.gov (United States)

    Jamaluddin, Naharullah; Abdullah, Ibrahim; Yusoff, Siti Fairus M.

    2015-09-01

    Natural rubber (NR) was modified to form liquid natural rubber (LNR) via photooxidative degradation. Hydrogenated liquid natural rubber (HLNR) was synthesized by using diimide as source of hydrogen which the diimide is produced by thermolysis of p-toluenesulfonyl hydrazide (TSH). The structure of HLNR was characterized by determining the changes of main peaks in Fourier Transform infrared and nuclear magnetic resonance spectra after hydrogenation. Thermogravimetric analysis showed that the HLNR had higher decomposition temperature compared to LNR and the decomposition temperature is directly proportional to the percentage of conversion.

  13. Thermal properties of hydrogenated liquid natural rubber

    International Nuclear Information System (INIS)

    Jamaluddin, Naharullah; Abdullah, Ibrahim; Yusoff, Siti Fairus M.

    2015-01-01

    Natural rubber (NR) was modified to form liquid natural rubber (LNR) via photooxidative degradation. Hydrogenated liquid natural rubber (HLNR) was synthesized by using diimide as source of hydrogen which the diimide is produced by thermolysis of p-toluenesulfonyl hydrazide (TSH). The structure of HLNR was characterized by determining the changes of main peaks in Fourier Transform infrared and nuclear magnetic resonance spectra after hydrogenation. Thermogravimetric analysis showed that the HLNR had higher decomposition temperature compared to LNR and the decomposition temperature is directly proportional to the percentage of conversion

  14. Thermal properties of hydrogenated liquid natural rubber

    Energy Technology Data Exchange (ETDEWEB)

    Jamaluddin, Naharullah; Abdullah, Ibrahim; Yusoff, Siti Fairus M. [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2015-09-25

    Natural rubber (NR) was modified to form liquid natural rubber (LNR) via photooxidative degradation. Hydrogenated liquid natural rubber (HLNR) was synthesized by using diimide as source of hydrogen which the diimide is produced by thermolysis of p-toluenesulfonyl hydrazide (TSH). The structure of HLNR was characterized by determining the changes of main peaks in Fourier Transform infrared and nuclear magnetic resonance spectra after hydrogenation. Thermogravimetric analysis showed that the HLNR had higher decomposition temperature compared to LNR and the decomposition temperature is directly proportional to the percentage of conversion.

  15. Preparation and properties of natural nanocomposites based on natural rubber and naturally occurring halloysite nanotubes

    International Nuclear Information System (INIS)

    Rooj, Sandip; Das, Amit; Thakur, Varun; Mahaling, R.N.; Bhowmick, Anil K.; Heinrich, Gert

    2010-01-01

    A 'green' composite based on natural halloysite nanotubes (HNTs) and natural rubber (NR) was prepared by mechanical mixing. A silane coupling agent, bis (triethoxysilylpropyl)-tetrasulphide, was utilized to enhance the properties of these composites. It was observed that the reinforcing activity of HNTs was superior to commercial silica coupled with the same amount of silane coupling agent. Moreover the on-set thermal degradation decomposition temperature was improved by ∼64 o C with the addition of 10 parts HNTs per hundred of rubber. Transmission electron microscopic images confirmed the good dispersion of the HNTs in the rubber matrix, whereas X-ray diffraction studies showed a little change in interlayer spacing between the two silicate layers of HNTs.

  16. Synergistic effect of plasma-modified halloysite nanotubes and carbon black in natural rubber-butadiene rubber blend

    NARCIS (Netherlands)

    Poikelispaa, Minna; Das, Amit; Dierkes, Wilma K.; Vuorinen, Jyrki

    2013-01-01

    Halloysite nanotubes (HNTs) were investigated concerning their suitability for rubber reinforcement. As they have geometrical similarity with carbon nanotubes, they were expected to impart a significant reinforcement effect on the rubber compounds but the dispersion of the nanofillers is difficult.

  17. Effect of concentrated epoxidised natural rubber and silica masterbatch for tyre application

    Energy Technology Data Exchange (ETDEWEB)

    Azira, A. A., E-mail: azira@lgm.gov.my; Kamal, M. M., E-mail: mazlina@lgm.gov.my [High Value Added Rubber Products and Nanostructured Materials, Stesen Penyelidikan RRIM, LGM 47000 Sungai Buloh, Selangor (Malaysia); Verasamy, D., E-mail: devaraj@lgm.gov.my [Environmental Technology & Sustainability, Technology & Engineering Division, Malaysian Rubber Board, Stesen Penyelidikan RRIM, LGM 47000 Sungai Buloh, Selangor (Malaysia)

    2016-07-06

    The availability of concentrated epoxidised natural rubber (ENR-LC) has provided a better opportunity for using epoxidised natural rubber (ENR) with silica to reinforce natural rubber for tyre application. ENR-LC mixed directly with silica to rubber by high speed stirrer without using any coupling agent. Some rubber compounds were prepared by mixing a large amount of precipitated amorphous white silica with natural rubber. The silica was prepared in aqueous dispersion and the filler was perfectly dispersed in the ENR-LC. The performance of the composites was evaluated in this work for the viability of ENR-LC/Si in tyre compounding. Compounding was carried out on a two roll mill, where the additives and curing agents was later mixed. Characterization of these composites was performed by Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM) for dispersion as well as mechanical testing. C-ENR/Si showed efficient as primary reinforcing filler in ENR with regard to modulus and tensile strength, resulting on an increase in the stiffness of the rubbers compared to ENR latex. Overall improvement in the mechanical properties for the ENR-LC over the control crosslinked rubber sample was probably due to synergisms of silica reinforcement and crosslinking of the polymeric matrix phase.

  18. Effect of concentrated epoxidised natural rubber and silica masterbatch for tyre application

    International Nuclear Information System (INIS)

    Azira, A. A.; Kamal, M. M.; Verasamy, D.

    2016-01-01

    The availability of concentrated epoxidised natural rubber (ENR-LC) has provided a better opportunity for using epoxidised natural rubber (ENR) with silica to reinforce natural rubber for tyre application. ENR-LC mixed directly with silica to rubber by high speed stirrer without using any coupling agent. Some rubber compounds were prepared by mixing a large amount of precipitated amorphous white silica with natural rubber. The silica was prepared in aqueous dispersion and the filler was perfectly dispersed in the ENR-LC. The performance of the composites was evaluated in this work for the viability of ENR-LC/Si in tyre compounding. Compounding was carried out on a two roll mill, where the additives and curing agents was later mixed. Characterization of these composites was performed by Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM) for dispersion as well as mechanical testing. C-ENR/Si showed efficient as primary reinforcing filler in ENR with regard to modulus and tensile strength, resulting on an increase in the stiffness of the rubbers compared to ENR latex. Overall improvement in the mechanical properties for the ENR-LC over the control crosslinked rubber sample was probably due to synergisms of silica reinforcement and crosslinking of the polymeric matrix phase.

  19. NMR relaxation times of natural rubber latex

    International Nuclear Information System (INIS)

    Harun, S.; Aziz, H.; Basir, Z.

    1994-01-01

    NMR relaxation times T sub 1 and T sub 2 of natural rubber latex have been measured at 25 degree C on a pulsed NMR spectrometer. The work focuses on the variation of the relaxation times with the amount of water content from 0% to 50%. The water content was adjusted by centrifuging and removing a certain amount of water from the sample. The data were analysed using a biexponential fitting procedure which yields simultaneously either T sub 1a and T sub 1b or T sub 2a and T sub 2b. The amount of solid was compared with the known amount of dry rubber content

  20. The Effect of Gamma Irradiation on the Mechanical Properties of vulcanized Natural Rubber and Natural Rubber-Polyethylene Blends

    International Nuclear Information System (INIS)

    Sudradjat Iskandar

    2008-01-01

    To enhance the quality of vulcanized natural rubber and natural rubber-polyethylene blends, gamma irradiation has been done. The compound of natural rubber and natural rubber-polyethylene blends made by using roll mill machine. The mixed materials were antioxidant, anti ozon, plasticizer and vulcanisator. The natural rubber and natural rubber-polyethylene blends compound were vulcanizer and made a slab (film of sample) using hot and could press machine. The slabs produced were then gamma irradiated at irradiation dose of 75, 150 and 300 kGy. Before and after irradiation, the slab were characterized using strograph R1 machine. The results showed that the modulus 300 and hardness of vulcanized natural rubber and natural rubber-polyethylene blends were increasing; the tensile strength and tear strength were increasing to maximum level then decreasing with gamma irradiation, while the elongation at break was decreasing. The maximum tensile strength of vulcanized natural rubber and natural rubber-polyethylene blends were found at irradiation dose of 75 kGy. At the irradiation dose of 75 kGy, the tensile strength of vulcanized natural rubber increased from 17.6 MN/m 2 to 21.2 MN/m 2 , while the tensile strength of vulcanized natural rubber-polyethylene blends increased slightly from 18.7 MN/m 2 to 19.4 MN/m 2 . (author)

  1. A comparative study of natural rubber modified with ground tire rubber of truck

    OpenAIRE

    Binti Haridan, Ili Liyana

    2016-01-01

    The recycling of waste rubber has considerable significance in term of environmental protection and energy conservation. Considering that most of the relevant literature is concerned with tire recycling, the aim of this work was to develop and characterize the elastomeric samples of natural rubber (NR) composites filled with ground tire rubber of truck (GTR) devulcanized by microwave (DGTR). The tire rubber was ground under ambient conditions and subjected to microwave exposure for 3, 5 and ...

  2. Performance Study of the Natural Rubber Composite with Clay Minerals

    International Nuclear Information System (INIS)

    Nyo Nyo Myint; Tin Tin Aye; Kyaw Myo Naing; Nyunt Wynn

    2008-03-01

    The preparation, characterization and some applications of natural rubber clay composite have been studied. This study investigated the possibility of natural rubber latex to replace some part of natural clays. In formulation of rubber clay composite from natural rubber latex and various clay minerals, three main steps were involved (i) preparation of latex cream (ii) prevulcanization of latex cream (iii) mixing vulcanized latex compound, with other ingredients. In each step, several parameters have been carefully investigated to optimize the performance of natural rubber clay composite production. The composite products were of better quality and can be considered to be more cost effective.

  3. Effect of Recycled Rubber Particles and Silica on Tensile and Tear Properties of Natural Rubber Composites

    Directory of Open Access Journals (Sweden)

    Velu CHANDRAN

    2016-05-01

    Full Text Available Application of scrap rubber and worn out tires in natural rubber compounds has been studied. The scrap rubber can, however, be recycled and compounded with natural rubber and thus can be generated as a rubber composite. In this work, recycled rubber particles (RRP were prepared using pulverization process. Then, RRP was blended with natural rubber and silica compounds, and it was synthesized by two- roll mill and hydraulic press at specified operating conditions. The samples ranging from 0 to 40 phr of RRP loaded with silica were used as constant filler. The mechanical properties and morphological analysis were carried out. The results showed that tensile strength and elongation at break gradually decreased with increasing RRP loading in natural rubber and silica compounds. Tensile modulus went down at 10 phr of RRP and then showed an increasing trend. Hardness increased up to 30 phr of RRP and tear strength increased up to 20 phr of RRP. A comparative study was also carried out with virgin natural rubber vulcanizates. The incorporation of RRP and silica up to 20 phr in natural rubber did not lower the performance of rubber articles. Morphological studies revealed that better filler dispersion, interfacial adhesion, and cross link density could increase the tensile and tear strengths.DOI: http://dx.doi.org/10.5755/j01.ms.22.2.7330

  4. Natural rubber (NR) biosynthesis: perspectives from polymer chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Barkakaty, Balaka [ORNL

    2014-01-01

    Natural rubber is an important strategic raw material for manufacturing a wide variety of industrial products. There are at least 2,500 different latex-producing plant species; however, only Hevea brasiliensis (the Brazilian rubber tree) is a commercial source. The chemical structure of natural rubber is cis-1,4-polyisoprene, but the exact structure of the head and end groups remains unknown. Since synthetic cis-1,4-polyisoprenes cannot match the superior properties of natural rubber, understanding the chemistry behind the biosynthetic process is key to finding a possible replacement. T his chapter summarizes our current understandings from the perspective of a polymer scientist by comparing synthetic polyisoprenes to natural rubber. The chapter also highlights biomimetic polymerization, research towards a synthetic match of natural rubber and the role of natural rubber in health care.

  5. Radiation vulcanization of Philippine natural rubber latex

    International Nuclear Information System (INIS)

    Dela Rosa, A.M.; Abad, L.V.; Sta.Ana-Relleve, L.P.; Tranquilan-Aranilla, C.O.; Pascual, C.L.

    1996-01-01

    The response of Philippine natural rubber latex to irradiation vulcanization and the stability of the irradiated natural rubber latex (INRL) upon storage and aging were investigated. Commercially available high ammonia (HA) concentrated latices obtained from various rubber plantations in Mindanao island were treated with 5 phr of n-butyl acrylate (nBA), and gamma-irradiated at the PNRI 60 Co irradiation facility at a dose rate of 2.57 kGy/hr. Unirradiated cast latex films gave different green strengths which varied from 2-11 MPa. Cast films from INRL exhibited maximum tensile strengths were obtained from cast films with low Mg and high nitrogen contents. Thermal analysis using thermogravimetry (TG) revealed one major decomposition product at 374 o -377 o C. Its rate of decomposition decreased to a minimum at 15 kGy, then increased as radiation dose was increased. This trend correlated well with the tensile strength measurements. The stability of the INRL upon storage and aging is an essential parameter to the rubbe latex industry. For storage studies, INRL was stored for various periods of time. It was found that the pH and total solids content of the stored INRL did not change significantly after 12 months of storage; the MST values remained at above 1000 seconds, and the viscosity decreased with time. The cast films exhibited a decline in tensile strength, modulus 300% , and crosslinking density upon storage. While there were observed changes in the physical properties of the INRL during the storage period, the data indicate that these properties were within values acceptable to the latex industry. Tests on the aging properties of INRL films were undertaken. It was shown that among the chemical antioxidants presently used by the latex industry, TNPP demonstrated the highest antioxidant property, followed by Antage DAHQ and Vulcanox BKF. Our data indicate that the natural rubber latex produced and processed in the Philippines is suited for radiation vulcanization

  6. The role of linked phospholipids in the rubber-filler interaction in carbon nanotube (CNT) filler natural rubber (NR) composites

    NARCIS (Netherlands)

    Le, H.H.; Abhijeet, S.; Ilish, S.; Klehm, J.; Henning, S.; Beiner, M.; Sarkawi, S.S.; Dierkes, Wilma K.; Das, A.; Fischer, D.; Stöckelhuber, K.-W.; Wiessner, S.; Khatiwada, S.P.; Adhikari, R.; Pham, T.; Heinrich, G.; Radusch, H.-J.

    2014-01-01

    The aim of the present work is to evidence the role of the linked phospholipids of natural rubber (NR) in the rubber-carbon nanotube (CNT) interactions in rubber composites. Three rubbers namely NR, deproteinized NR (DPNR) and a synthetic rubber isoprene (IR) were used as matrix for CNTs. The

  7. Natural Rubber Modification For Upper Layer Of Rubberized Asphalt Paving Block AS Shock Absorber

    OpenAIRE

    Nasruddin, Nasruddin

    2017-01-01

    The research of rubber compounding modification for upper layer of rubberized asphalt paving block as shock absorber using natural rubber, styrene butadiene rubber (SBR) as synthetic rubber, fly ash as filler and also vegetable oil as plasticizer has been conducted. The research design was varying the filler Si-69, fly ash and palm oil. The five formulas A, B, C, D, and E designed by varying the amount of Si-69 (48.5; 50.75; 53.00; 55.25; and 57.50) phr; coal fly ash (4.75, 7.00, 9.25, 11.50 ...

  8. Radiation vulcanization of Philippine natural rubber latex

    International Nuclear Information System (INIS)

    Dela Rosa, Alumanda M.; Abad, Lucille V.; Sta, Lorna P.; Ana-Relleve; Tranquilan-Aranilla, Charito O.; Pascual, Cristina L.

    1996-01-01

    The response of Philippine natural rubber latex to radiation vulcanization and the stability of the irradiated natural rubber latex (INRL) upon storage and aging were investigated. Commercially available high ammonia (HA) concentrated lattices obtained from various rubber plantations in Mindanao Island were treated with 5 phr of n-butyl acrylate (nBA), and gamma-irradiated at the PNRI sup 60 Co irradiation facility at dose rate of 2.57 KGy/hr. Unirradiated cast latex films gave different green strength which varied from 2 - 11 MPa. Cast films from INRL exhibited maximum tensile strengths of 25 - 32 MPa at a radiation dose of 15 kGy. Higher tensile strengths were obtained from cast films with low Mg and high nitrogen contents. Thermal analysis using thermogravimetry (TG) revealed one major decomposition product at 374 degree C - 377 degree C. Its rate of decomposition decreased to a minimum at 15 kGy, then increased as radiation dose increased. This trend correlated well with the tensile strength measurements. The stability of the INRL upon storage and aging is an essential parameter to the rubber latex industry. For storage studies, INRL was stored for various periods of time. It was found that the pH and total solids content of the stored INRL did not change significantly after 12 months of storage; the MST values remained at above 100 seconds, and the viscosity decreased with time. The cast films exhibited a decline in tensile strength, modulus 300% and crosslinking density upon storage. While there were observed changes in the physical properties of the IRNL during the storage period, the data indicate that these properties were within values acceptable to the latex industry. Tests on the aging properties of INRL film were undertaken. It was shown that among the chemical antioxidants presently used by the latex industry. TNPP demonstrated the highest antioxidant property, followed by Antage DAHQ and Vulcanox BKF. Our data indicate that the natural rubber latex

  9. Shape memory alloy wire-based smart natural rubber bearing

    International Nuclear Information System (INIS)

    Hedayati Dezfuli, F; Shahria Alam, M

    2013-01-01

    In this study, two types of smart elastomeric bearings are presented using shape memory alloy (SMA) wires. Due to the unique characteristics of SMAs, such as the superelastic effect and the recentering capability, the residual deformation in SMA-based natural rubber bearings (SMA-NRBs) is significantly reduced whereas the energy dissipation capacity is increased. Two different configurations of SMA wires incorporated in elastomeric bearings are considered. The effect of several parameters, including the shear strain amplitude, the type of SMA, the aspect ratio of the base isolator, the thickness of SMA wire, and the amount of pre-strain in the wires on the performance of SMA-NRBs is investigated. Rubber bearings are composed of natural rubber layers bonded to steel shims as reinforcement. Results show that ferrous SMA wire, FeNiCuAlTaB, with 13.5% superelastic strain and a very low austenite finish temperature (−62 °C), is the best candidate to be used in SMA-NRBs subjected to high shear strain amplitudes. In terms of the lateral flexibility and wire strain level, the smart rubber bearing with a cross configuration of SMA wires is more efficient. Moreover, the cross configuration can be implemented in high-aspect-ratio elastomeric bearings since the strain induced in the wire does not exceed the superelastic range. When cross SMA wires with 2% pre-strain are used in a smart NRB, the dissipated energy is increased by 74% and the residual deformation is decreased by 15%. (paper)

  10. New Green Polymeric Composites Based on Hemp and Natural Rubber Processed by Electron Beam Irradiation

    Directory of Open Access Journals (Sweden)

    Maria-Daniela Stelescu

    2014-01-01

    Full Text Available A new polymeric composite based on natural rubber reinforced with hemp has been processed by electron beam irradiation and characterized by several methods. The mechanical characteristics: gel fraction, crosslink density, water uptake, swelling parameters, and FTIR of natural rubber/hemp fiber composites have been investigated as a function of the hemp content and absorbed dose. Physical and mechanical properties present a significant improvement as a result of adding hemp fibres in blends. Our experiments showed that the hemp fibers have a reinforcing effect on natural rubber similar to mineral fillers (chalk, carbon black, silica. The crosslinking rates of samples, measured using the Flory-Rehner equation, increase as a result of the amount of hemp in blends and the electron beam irradiation dose increasing. The swelling parameters of samples significantly depend on the amount of hemp in blends, because the latter have hydrophilic characteristics.

  11. Radiation response of Philippine natural rubber latex

    International Nuclear Information System (INIS)

    Dela Rosa, A.M.; Abad, L.V.; Ana-Relleve, L.S.; Tranquilan-Aranilla, C.; Pascual, C.L.

    1998-01-01

    Our earlier work has shown that the natural rubber latex (NRL) produced and processed in the Philippines is suited for radiation vulcanization. The cast films from NRL with 50% TSC exhibited maximum tensile strengths of 25-32 MPa at 15 kGy, which is the vulcanization dose or Dv. In the manufacture of dipped NRL products, certain specifications such as %TSC, protein content and tensile properties, must be met to ensure an acceptable product. For radiation vulcanization of natural rubber latex (RVNRL) to be accepted as an alternative process, it must also meet the requirements. Thus, this paper presents additional data on the radiation response of local NRL at different total solids contents (TSC), leachable proteins from NRL films as a function of dose, and the thermal activities of irradiated natural rubber latex (INRL). Different formulations of NRL showed varying tolerances to nBA. Data showed that as %TSC increases, the maximum concentration of nBA that can be added without affecting the stability of the latex decreases. The Dv increases as the %TSC increases and the nBA content decreases. This difference in response may be attributed to a lower concentration of nBA in formulations with higher %TSC. These data indicate that the parameters in the radiation treatment will be dictated by the intended applications of INRL. The thermogravimetric data showed greater stability of INRL to thermal oxidation relative to the unirradiated NRL, which correlates directly with the tensile properties of the INRL. A radiation dose of 10 kGy increased the amount of proteins leached from cast latex films. The amount of extractable proteins did not increase significantly at higher doses. The SDS PAGE analysis of the extractable proteins from unirradiated latex film showed distinct bands. An additional band at 60 Kda appeared at 10 kGy. All these bands became diffuse at higher doses, indicating the radiolysis of the proteins

  12. Reinforcement of tire tread and radiator hose rubbers with short aramid fibers

    NARCIS (Netherlands)

    Shirazi, Morteza; Noordermeer, Jacobus W.M.

    2010-01-01

    Short fiber reinforced rubber composites have gained great importance due to their advantages in processing and low cost, coupled with high strength. Reinforcement with short fibers offers attractive features such as design flexibility, high modulus, tear strength, etc. The degree of reinforcement

  13. A Review on Using Crumb Rubber in Reinforcement of Asphalt Pavement

    Science.gov (United States)

    Mashaan, Nuha Salim; Ali, Asim Hassan; Karim, Mohamed Rehan; Abdelaziz, Mahrez

    2014-01-01

    An immense problem affecting environmental pollution is the increase of waste tyre vehicles. In an attempt to decrease the magnitude of this issue, crumb rubber modifier (CRM) obtained from waste tyre rubber has gained interest in asphalt reinforcement. The use of crumb rubber in the reinforcement of asphalt is considered as a smart solution for sustainable development by reusing waste materials, and it is believed that crumb rubber modifier (CRM) could be an alternative polymer material in improving hot mix asphalt performance properties. In this paper, a critical review on the use of crumb rubber in reinforcement of asphalt pavement will be presented and discussed. It will also include a review on the effects of CRM on the stiffness, rutting, and fatigue resistance of road pavement construction. PMID:24688369

  14. A Review on Using Crumb Rubber in Reinforcement of Asphalt Pavement

    Directory of Open Access Journals (Sweden)

    Nuha Salim Mashaan

    2014-01-01

    Full Text Available An immense problem affecting environmental pollution is the increase of waste tyre vehicles. In an attempt to decrease the magnitude of this issue, crumb rubber modifier (CRM obtained from waste tyre rubber has gained interest in asphalt reinforcement. The use of crumb rubber in the reinforcement of asphalt is considered as a smart solution for sustainable development by reusing waste materials, and it is believed that crumb rubber modifier (CRM could be an alternative polymer material in improving hot mix asphalt performance properties. In this paper, a critical review on the use of crumb rubber in reinforcement of asphalt pavement will be presented and discussed. It will also include a review on the effects of CRM on the stiffness, rutting, and fatigue resistance of road pavement construction.

  15. Radiation vulcanization of natural rubber latex

    International Nuclear Information System (INIS)

    Wan Manshol bin Wan Zin; Norjanah binti Mohid

    1994-01-01

    This paper describes the experimental techniques and the results of radiation vulcanization of natural rubber latex carried out on several high ammonia latices available in the country. The efficiency of various sensitisers and stabilisers used were evaluated in terms of the gamma radiation dose required to produce the maximum tensile strengths. The extent of crosslinking of RVNRL sample films were estimated by equilibrium swelling ratio measurements. The stability of pre-irradiated and post-irradiated samples were monitored using viscosity measurements as the parameter

  16. The Effect of Rubber Mixing Process on The Curing Characteristics of Natural Rubber

    Directory of Open Access Journals (Sweden)

    Abu Hasan

    2013-04-01

    Full Text Available This research is aimed at studying the relationship between rubber mixing processes and curing characteristics of natural rubber. The curing characteristic analysis was carried out through a natural rubber formula having been masticated and mixed, followed by curing. As many as four mastication methods were finely applied; each respected four sequences of rubber mixing process. In the first method, rubber was masticated for 5 minutes and then rubber chemicals and carbon black N 330 were  simultaneously added. In the second and the third methods, rubber was masticated for 1 minute and then carbon blacks and rubber chemicals were also simultaneously added but using different type of fillers. In the fourth method, rubber was masticated for 3 minutes and then rubber chemicals and carbon black were subsequently added. The additions of rubber chemicals and carbon blacks to the masticated rubber were distinguished by the sequence and time allocated for each mixing process. The carbon blacks were added in two stages by which 10 phr was added first and the remaining 40 phr was added later along with oil. In another method, ratios of the carbon blacks addition (as done in the first  and the second stages were 20:30, 30:20, and 40:10. The examination results showed that rubber mixing process gave an impact on the changes of curing characteristics. They were much affected by the method of carbon black addition. The mixing temperature also had an effect on both curing time and curing rate in which the higher the mixing temperature, the lower the curing time and curing rate. Vulcanization temperature also affected the curing time and curing rate in which the higher the vulcanization temperature, the lower the curing time and the higher the curing rate. Lastly, particle size of carbon black also gave an impact on the curing time and curing rate in which the smaller the particle size, the lower the curing time and the higher the curing rate.

  17. Use of Steel Fiber-Reinforced Rubberized Concrete in Cold Regions

    Science.gov (United States)

    2017-12-24

    This report documents and presents the use of steel fiber-reinforced rubberized concrete (SFRRC) in cold regions. Further investigation of SFRRC use was conducted with the wheel tracker rut and freeze-thaw laboratory testing procedures at the Univers...

  18. The use of radiotracers in natural rubber research in Malaysia

    International Nuclear Information System (INIS)

    Lai, P.F.; Singh, M.M.

    1981-01-01

    Five main areas where radiotracers have been used in research on natural rubber are on studies on the uptake of plant nutrients by Hevea brasiliensis using 32 P, 86 Rb and 45 Ca as tracers; biosynthesis of Hevea rubber using 14 C or 3 H labelled intermediates; translocation and metabolism of 14 C. Ethephon in Hevea brasiliensis; use of radiotracers as analytical tools and adsorption of labelled fatty acid soaps on natural rubber lattices. These studies are discussed to show the powerful tool that radiotracers provide in agricultural, biochemical and chemical research on natural rubber. (author)

  19. Structural characterization of rubber from jackfruit and euphorbia as a model of natural rubber.

    Science.gov (United States)

    Mekkriengkrai, Dararat; Ute, Koiichi; Swiezewska, Ewa; Chojnacki, Tadeusz; Tanaka, Yasuyuki; Sakdapipanich, Jitladda T

    2004-01-01

    A structural study of low molecular weight rubbers from Jackfruit (Artocarpus heterophyllus) and Painted spurge (Euphorbia heterophylla) was carried out as model compounds of natural rubber from Hevea brasiliensis. The rubber content of latex from Jackfruit was 0.4-0.7%, which is very low compared with that of 30-35% in the latex from Hevea tree. The rubber from Jackfruit latex was low molecular weight with narrow unimodal molecular weight distribution (MWD), whereas that obtained from E. heterophylla showed very broad MWD. The 1H and 13C NMR analyses showed that Jackfruit rubber consists of a dimethylallyl group and two trans-isoprene units connected to a long sequence of cis-isoprene units. The alpha-terminal group of Jackfruit rubber was presumed to be composed of a phosphate group based on the presence of 1H NMR signal at 4.08 ppm corresponding to the terminal =CH-CH2OP group.

  20. Functionalization of Liquid Natural Rubber via Oxidative Degradation of Natural Rubber

    Directory of Open Access Journals (Sweden)

    Suhawati Ibrahim

    2014-12-01

    Full Text Available Natural rubber (NR is a high molecular weight natural polymer and can be degraded to liquid natural rubber (LNR leaving certain functional groups at the end of chains. In this study, LNR samples prepared via oxidative degradation using H2O2 and NaNO2 as reagents were found to have different end groups depending on the pH of the reaction medium. In an acidic medium, LNR with hydroxyl terminal groups was formed as the degradation reaction was initiated by hydroxyl radicals produced from decomposition of peroxynitrite acid. In contrast, a redox reaction took place in an alkaline medium to yield LNR with carbonyl terminal groups. The mechanisms of reaction are discussed and proposed to explain the formation of different end groups when reaction carried out in acidic and alkaline media. Chain degradation in an acidic medium seems to be more effective than in an alkaline medium, and thus yields LNR with lower Mn.

  1. A comparative investigation on strain induced crystallization for graphene and carbon nanotubes filled natural rubber composites

    Directory of Open Access Journals (Sweden)

    D. H. Fu

    2015-07-01

    Full Text Available Natural rubber containing graphene and carbon nanotubes (CNTs composites were prepared by ultrasonicallyassisted latex mixing. Natural rubber filled by both graphene and CNTs show significant enhanced tensile strength, while graphene exhibits a better reinforcing effect than CNTs. Strain-induced crystallization in natural rubber composites during stretching was determined by synchrotron wide-angle X-ray diffraction. With the addition of CNTs or graphene, the crystallization for natural rubber occurs at a lower strain compared to unfilled natural rubber, and the strain amplification effects were observed. The incorporation of graphene results in a faster strain-induced crystallization rate and a higher crystallinity compared to CNTs. The entanglement-bound rubber tube model was used to analyze the chain network structure and determine the network parameters of composites. The results show that the addition of graphene or CNTs has an influence on the molecular network structure and improves the contribution of entanglement to the conformational constraint, while graphene has a more marked effect than CNTs.

  2. Development of radiation-curable resin based on natural rubber

    Energy Technology Data Exchange (ETDEWEB)

    Mohd, Dahlan; Harun, Abdul Ghani [Nuclear Energy Unit, Bangi, Selangor (Malaysia)

    1994-12-31

    A new radiation curable resin based on natural rubber has been developed. The resin was based on the reaction between low molecular weight epoxidised natural rubber and acrylic acid. When formulated with reactive monomers and photoinitiator, it solidified upon irradiation with UV light. The resin may find applications in coating for cellulosic-based substrates and pressure-sensitive adhesive.

  3. Development of radiation-curable resin based on natural rubber

    International Nuclear Information System (INIS)

    Dahlan Mohd; Abdul Ghani Harun

    1993-01-01

    A new radiation curable resin based on natural rubber has been developed. The resin was based on the reaction between low molecular weight epoxidised natural rubber and acrylic acid. When formulated with reactive monomers and photoinitiator, it solidified upon irradiation with UV light. The resin may find applications in coating for cellulosic-based substrates and pressure-sensitive adhesive

  4. Toughening of carbon fibre reinforced polymer composites with rubber nanoparticles for advanced industrial applications

    Directory of Open Access Journals (Sweden)

    N. G. Ozdemir

    2016-05-01

    Full Text Available This study investigates the effects of nano carboxylic acrylonitrile butadiene rubber (CNBR-NP and nano acrylonitrile butadiene rubber (NBR-NP on the interlaminar shear strength and fracture toughness of carbon fibre reinforced polymer composites (CFRP with dicyandiamide-cured epoxy matrix. The results show that nano-size dispersion of rubber significantly improved the Mode I delamination fracture toughness (GIC of the CFRP by 250% and its Mode II delamination fracture toughness (GIIC by 80% with the addition of 20 phr of CNBR-NP. For the NBR-NP system, the GIC and GIIC delamination fracture toughness of the CFRP were increased by 200 and 80% respectively with the addition of 20 phr (parts per hundred rubber of nano rubber to the matrix. Scanning electron microscopy (SEM images of the fracture surface revealed that the toughening was mainly achieved by debonding of the nano rubber, crack path deflection and fibre bridging.

  5. Ultraviolet curing of acrylated liquid natural rubber for surface coating application

    OpenAIRE

    Kannikar Kwanming; Pairote Klinpituksa; Wae-asae Waehamad

    2009-01-01

    Ultraviolet curable acrylated liquid natural rubber was prepared by grafting of photosensitive molecule onto liquid natural rubber for surface coating application. The liquid natural rubber (LNR) was firstly obtained by degradation of natural rubber latex with hydrogen peroxide and cobalt acetylacetonate at 65oC for 72 hrs. The preparation of acrylated natural rubber was carried out by the reaction of acrylic acid and epoxidized liquid natural rubber (ELNR) prior obtained from LNR with formic...

  6. Radiation vulcanization of natural rubber latex sensitized with commercial gases

    Energy Technology Data Exchange (ETDEWEB)

    Chirinos, H.; Lugao, A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    2002-07-01

    The industrial activities using natural rubber latex are fully compatible with rural areas in Amazon and other places in Brazil, as well as in other tropical countries. However the classical sulfur vulcanization presents many occupational problems for the workers in rural areas. Radiation vulcanization of natural rubber latex is a much more friendly process as sulfur compounds are not needed for crosslinking, although chemicals as acrylate monomers, particularly multifunctional acrylates are still used as sensitizers for radiation processes. Two commercial gases, acetylene and butadiene, were selected as sensitizers for the radiation vulcanization of natural rubber latex instead of acrylates. These gases accelerate the crosslinking rates of the cure process and lower the radiation dose required to achieve vulcanization of natural rubber latex and improve the mechanical properties to reduce the tackiness of rubber goods. (author)

  7. Radiation vulcanization of natural rubber latex sensitized with commercial gases

    International Nuclear Information System (INIS)

    Chirinos, H.; Lugao, A.

    2002-01-01

    The industrial activities using natural rubber latex are fully compatible with rural areas in Amazon and other places in Brazil, as well as in other tropical countries. However the classical sulfur vulcanization presents many occupational problems for the workers in rural areas. Radiation vulcanization of natural rubber latex is a much more friendly process as sulfur compounds are not needed for crosslinking, although chemicals as acrylate monomers, particularly multifunctional acrylates are still used as sensitizers for radiation processes. Two commercial gases, acetylene and butadiene, were selected as sensitizers for the radiation vulcanization of natural rubber latex instead of acrylates. These gases accelerate the crosslinking rates of the cure process and lower the radiation dose required to achieve vulcanization of natural rubber latex and improve the mechanical properties to reduce the tackiness of rubber goods. (author)

  8. Rubber

    Science.gov (United States)

    Graves, D. F.

    The word "rubber" immediately brings to mind materials that are highly flexible and will snap back to their original shape after being stretched. In this chapter a variety of materials are discussed that possess this odd characteristics. There will also be a discussion on the mechanism of this "elastic retractive force." Originally, rubber meant the gum collected from a tree growing in Brazil. The term "rubber" was coined for this material by the English chemist Joseph Priestley, who noted that it was effective for removing pencil marks from paper. Today, in addition to Priestley's natural product, many synthetic materials are made that possess these characteristics and many other properties. The common features of these materials are that they are made up of long-chain molecules that are amorphous (not crystalline), and the chains are above their glass transition temperature at room temperature.

  9. Behavior of granular rubber waste tire reinforced soil for application in geosynthetic reinforced soil wall

    Directory of Open Access Journals (Sweden)

    G. G. D. RAMIREZ

    Full Text Available AbstractLarge quantities of waste tires are released to the environment in an undesirable way. The potential use of this waste material in geotechnical applications can contribute to reducing the tire disposal problem and to improve strength and deformation characteristics of soils. This paper presents a laboratory study on the effect of granular rubber waste tire on the physical properties of a clayey soil. Compaction tests using standard effort and consolidated-drained triaxial tests were run on soil and mixtures. The results conveyed an improvement in the cohesion and the angle of internal friction the clayey soil-granular rubber mixture, depending on the level of confining stress. These mixtures can be used like backfill material in soil retaining walls replacing the clayey soil due to its better strength and shear behavior and low unit weight. A numerical simulation was conducted for geosynthetic reinforced soil wall using the clayey soil and mixture like backfill material to analyzing the influence in this structure.

  10. Preparation of vinyl acetate grafted natural rubber by irradiation method

    Energy Technology Data Exchange (ETDEWEB)

    Porntrairat, A.; Pattamaprom, C. [Center of Excellence on Natural Rubber Technology, Department of Chemical Engineering, Faculty of Engineering, Thammasat University, Pathumthani 12120 (Thailand)

    2016-03-09

    Improvement in properties of natural rubber could be done by several methods. In this research, gamma radiation technique, which is simple, accurate, easy to control and clean, was applied to enhance the properties of natural rubber (NR) in latex state. The purpose of this research is to study the appropriate condition for preparing grafted natural rubber latex by using irradiation method. Vinyl acetate monomers (VAc) were grafted onto natural rubber latex (NR-g-PVAc) at 0-10 kGys by gamma radiation from Cobalt-60 source at room temperature. Physical properties of grafted natural rubber such as chloroform number, swelling ratio and gel content were measured. The VAc content of NR-g-PVAc was investigated by titration and visualized by FTIR spectroscopy. The FTIR spectra of NR-g-PVAc prepared at 0-10 kGys showed characteristic peaks of the vinyl acetate confirming that VAc could be grafted onto natural rubber molecular chains effectively under appropriate irradiation conditions. From the result, radiation grafting was found to be a useful technique for grafting of vinyl acetate onto natural rubber.

  11. Carboxy terminated rubber based on natural rubber grafted with acid anhydrides and its adhesion properties

    International Nuclear Information System (INIS)

    Klinpituksa, P; Kongkalai, P; Kaesaman, A

    2014-01-01

    The chemical modification of natural rubber by grafting of various polar functional molecules is an essential method, improving the versatility of rubber in applications. This research investigated the preparation of natural rubber-graft-citraconic anhydride (NR-g-CCA), natural rubber-graft-itaconic anhydride (NR-g-ICA), and natural rubber-graft-maleic anhydride (NR-g-MA), with the anhydrides grafted to natural rubber in toluene using benzoyl peroxide as an initiator. Variations of monomer content, initiator content, temperature and reaction time of the grafting copolymerization were investigated. The maximum degrees of grafting were 1.06% for NR-g-CCA, 4.66% for NR-g-ICA, and 5.03% for NR-g-MA, reached using 10 phr citraconic anhydride, 10 phr of itaconic anhydride, or 8 phr of maleic anhydride, 3 phr benzoyl peroxide, at 85, 80 and 80°C for 2, 2 and 3 hrs, respectively. Solvent-based wood adhesives were formulated from these copolymers with various contents of wood resin in the range 10-40 phr. The maximal 289 N/in cleavage peel and 245.7 KPa shear strength for NR-g-MA (5.03% grafting) were obtained at 40 phr wood resin

  12. Fabrication of shape memory natural rubber using palmitic acid

    Directory of Open Access Journals (Sweden)

    Jeff Sze-Hua Wee

    2017-10-01

    Full Text Available This paper investigates the practicability of fabricating a shape memory natural rubber with the use of palmitic acid as the swelling agent. Strips of natural rubber samples were swollen in molten palmitic acid at 75 °C. Equilibrium swelling of natural rubber with palmitic acid was found to occur at approximately 50 min of swelling time. Under cooling effect, the palmitic acid crystallized to form a percolated crystalline platelet network. These networks allow fabricated shape memory natural rubber (SMNR to deform and recover its shape at a temperature above the melting point of palmitic acid. Under controlled uniaxial stress, the natural rubber sample with 0 parts per hundred rubber (phr carbon black loading exhibits fixity and recovery of 80 ± 10%. Motivation of this research is primarily on practicability of palmitic acid to be used as a swelling agent for shape memory properties. Results show that palmitic acid is a relatively good swelling agent to induce shape memory properties into natural rubber.

  13. Sugarcane bagasse ash: new filler to natural rubber composite

    Directory of Open Access Journals (Sweden)

    Renivaldo José dos Santos

    2014-12-01

    Full Text Available Waste recycling has been the subject of numerous scientific researches regarding the environmental care. This paper reports the redirecting of sugarcane bagasse ash (SBA as new filler to natural rubber (NR/SBA. The NR/SBA composites were prepared using an opened cylinder mixer to incorporate the vulcanization agents and different proportions of residue (SBA. The ash contains about 70-90% of inorganic compounds, with silica (SiO2 being the main compound. The SBA incorporation improved the mechanical properties of the vulcanized rubber. Based on these results, a new use is proposed for the agro-industry organic waste to be implemented in the rubber vulcanization process, aimed at improving the rubber physical properties as well as decreasing the prices of natural rubber composites.

  14. Interfacial interaction between the epoxidized natural rubber and silica in natural rubber/silica composites

    Science.gov (United States)

    Xu, Tiwen; Jia, Zhixin; Luo, Yuanfang; Jia, Demin; Peng, Zheng

    2015-02-01

    The epoxidized natural rubber (ENR) as an interfacial modifier was used to improve the mechanical and dynamical mechanical properties of NR/silica composites. In order to reveal the interaction mechanism between ENR and silica, the ENR/Silica model compound was prepared by using an open mill and the interfacial interaction of ENR with silica was investigated by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), X-ray diffraction (XRD) and stress-strain testing. The results indicated that the ring-opening reaction occurs between the epoxy groups of ENR chains and Si-OH groups on the silica surfaces and the covalent bonds are formed between two phases, which can improve the dispersion of silica in the rubber matrix and enhance the interfacial combination between rubber and silica. The ring-opening reaction occurs not only in vulcanization process but also in mixing process, meanwhile, the latter seems to be more important due to the simultaneous effects of mechanical force and temperature.

  15. Interfacial interaction between the epoxidized natural rubber and silica in natural rubber/silica composites

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Tiwen [College of Materials Science and Engineering, South China University of Technology, Guangzhou 510640 (China); Jia, Zhixin, E-mail: zxjia@scut.edu.cn [College of Materials Science and Engineering, South China University of Technology, Guangzhou 510640 (China); Luo, Yuanfang; Jia, Demin [College of Materials Science and Engineering, South China University of Technology, Guangzhou 510640 (China); Peng, Zheng [Agricultural Product Processing Research Institute, Chinese Academy of Tropical Agriculture Sciences, Zhanjiang 524001 (China)

    2015-02-15

    Highlights: • Substantiate the ring open reaction between Si-OH of silica and epoxy groups of ENR. • ENR can act as a bridge between NR and silica to enhance the interfacial interaction. • As a modifier, ENR gets the potential to be used in the tread of green tire for improving the wet skid resistance apparently. - Abstract: The epoxidized natural rubber (ENR) as an interfacial modifier was used to improve the mechanical and dynamical mechanical properties of NR/silica composites. In order to reveal the interaction mechanism between ENR and silica, the ENR/Silica model compound was prepared by using an open mill and the interfacial interaction of ENR with silica was investigated by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), X-ray diffraction (XRD) and stress–strain testing. The results indicated that the ring-opening reaction occurs between the epoxy groups of ENR chains and Si-OH groups on the silica surfaces and the covalent bonds are formed between two phases, which can improve the dispersion of silica in the rubber matrix and enhance the interfacial combination between rubber and silica. The ring-opening reaction occurs not only in vulcanization process but also in mixing process, meanwhile, the latter seems to be more important due to the simultaneous effects of mechanical force and temperature.

  16. Biodegradation behavior of styrene butadiene rubber (SBR) reinforced with modified coconut shell powder

    Science.gov (United States)

    Sreejith, M. P.; Balan, Aparna K.; Shaniba, V.; Jinitha, T. V.; Subair, N.; Purushothaman, E.

    2017-06-01

    Biodegradation behavior of styrene butadiene rubber composites reinforced with natural filler, coconut shell powder (CSP), with different filler loadings were carried out under soil burial conditions for three to six months. The extent of biodegradation of the composites was evaluated through weight loss, tensile strength and hardness measurements. It was observed that the permanence of the composites was remarkably dependent on filler modification, size of the filler particle and filler content. Composites containing silane modified filler were found to be more resistant to attack by the microbes present in the soil. Mechanical properties such as tensile strength, Young's modulus and hardness were decreased after soil burial testing due to the microbial attack onto the samples.

  17. Forecasting Natural Rubber Price In Malaysia Using Arima

    Science.gov (United States)

    Zahari, Fatin Z.; Khalid, Kamil; Roslan, Rozaini; Sufahani, Suliadi; Mohamad, Mahathir; Saifullah Rusiman, Mohd; Ali, Maselan

    2018-04-01

    This paper contains introduction, materials and methods, results and discussions, conclusions and references. Based on the title mentioned, high volatility of the price of natural rubber nowadays will give the significant risk to the producers, traders, consumers, and others parties involved in the production of natural rubber. To help them in making decisions, forecasting is needed to predict the price of natural rubber. The main objective of the research is to forecast the upcoming price of natural rubber by using the reliable statistical method. The data are gathered from Malaysia Rubber Board which the data are from January 2000 until December 2015. In this research, average monthly price of Standard Malaysia Rubber 20 (SMR20) will be forecast by using Box-Jenkins approach. Time series plot is used to determine the pattern of the data. The data have trend pattern which indicates the data is non-stationary data and the data need to be transformed. By using the Box-Jenkins method, the best fit model for the time series data is ARIMA (1, 1, 0) which this model satisfy all the criteria needed. Hence, ARIMA (1, 1, 0) is the best fitted model and the model will be used to forecast the average monthly price of Standard Malaysia Rubber 20 (SMR20) for twelve months ahead.

  18. Competitiveness and Exports Sustainability of the Indonesian Natural Rubber

    Directory of Open Access Journals (Sweden)

    Rumbiati Kamaludin

    2018-03-01

    Full Text Available This paper examines Indonesian competitiveness in export of natural rubber commodities by employing set of revealed comparative advantage (RCA and Export competitive index (ECI with respect to global trade. The market structure that is formed on natural rubber commodities is calculated using Herfindahl Index and Concentration Ratio analysis tools shows the oligopoly-shaped market structure. Calculation of comparative advantage with RCA analysis shows that the four countries exporting natural rubber, namely Thailand, Indonesia, Malaysia and Vietnam each have a comparative advantage. Where Indonesia has a better comparative advantage than Thailand in the period 2011 to 2015. This result is different from the calculations made on competitive advantage (ECI in which Indonesia's natural rubber commodities are not more competitive than Thailand

  19. Effect of Graphite on the Properties of Natural Rubber

    Directory of Open Access Journals (Sweden)

    Auda jabber Braihi

    2016-09-01

    Full Text Available Natural rubber-graphite composites (0, 1, 2, 3, 4 pphr graphite were prepared on a laboratory two-roll mill. Swelling measurements were used to evaluate the impacts of graphite on the properties of natural rubber. Swelling results showed that the volume fraction of natural rubber in the swollen gel, the interaction parameter, and the cross-link density decreased by increasing graphite loadings, while the average molecular weight of natural rubber between cross-links increased. Vulcanization results showed that only scorch time parameter increased with increasing graphite loadings, while other parameters (Max. torque, Min. torque, cure rate and cure rate index decreased. Both thermal and AC conductivities increased.

  20. Permeation Behavior and Physical Properties of Natural Rubber Nanocomposites

    National Research Council Canada - National Science Library

    Zukas, Walter; Sennett, Michael; Welsh, Elizabeth; Rodriguez, Axel; Ziegler, David; Touchet, Paul

    2004-01-01

    .... A study was carried out to examine the effects of varying nanoparticle morphology and composition on the mechanical and barrier properties of polymer nanocomposites made with natural rubber (NR...

  1. Studies on Hydrogenation of Liquid Natural Rubber Using Diimide

    Directory of Open Access Journals (Sweden)

    Nur Hanis Adila Azhar

    2015-01-01

    Full Text Available Liquid natural rubber (LNR is a depolymerized natural rubber (NR which consists of shorter polymeric chains and lower molecular weight (Mw90% was achieved by manipulating the reaction parameters such as sources of diimide, TSH concentration, solvent, and reaction time. The optimum condition was 3 : 1 weight ratio of TSH/LNR in o-xylene at 130°C in 4-hour reaction period.

  2. Time series analysis of the behavior of brazilian natural rubber

    Directory of Open Access Journals (Sweden)

    Antônio Donizette de Oliveira

    2009-03-01

    Full Text Available The natural rubber is a non-wood product obtained of the coagulation of some lattices of forest species, being Hevea brasiliensis the main one. Native from the Amazon Region, this species was already known by the Indians before the discovery of America. The natural rubber became a product globally valued due to its multiple applications in the economy, being its almost perfect substitute the synthetic rubber derived from the petroleum. Similarly to what happens with other countless products the forecast of future prices of the natural rubber has been object of many studies. The use of models of forecast of univariate timeseries stands out as the more accurate and useful to reduce the uncertainty in the economic decision making process. This studyanalyzed the historical series of prices of the Brazilian natural rubber (R$/kg, in the Jan/99 - Jun/2006 period, in order tocharacterize the rubber price behavior in the domestic market; estimated a model for the time series of monthly natural rubberprices; and foresaw the domestic prices of the natural rubber, in the Jul/2006 - Jun/2007 period, based on the estimated models.The studied models were the ones belonging to the ARIMA family. The main results were: the domestic market of the natural rubberis expanding due to the growth of the world economy; among the adjusted models, the ARIMA (1,1,1 model provided the bestadjustment of the time series of prices of the natural rubber (R$/kg; the prognosis accomplished for the series supplied statistically adequate fittings.

  3. Verification of Interactions between Silica and Epoxidized Squalene as a Model for Epoxidized Natural Rubber

    NARCIS (Netherlands)

    Kaewsakul, Wisut; Sahakaro, Kannika; Dierkes, Wilma K.; Noordermeer, Jacobus W.M.

    2014-01-01

    Unmodified squalene (Sq) and epoxidised squalene (ESq), as models for natural rubber and epoxidised natural rubber, were mixed with silica in a reactor at 140 – 145ºC, which corresponds to the optimal mixing dump temperature of silica-filled natural rubber or epoxidised natural rubber compounds. The

  4. Radiation-induced deterioration of natural rubber and isoprene rubber vulcanizates

    International Nuclear Information System (INIS)

    Kohjiya, Shinzo; Matsumura, Yasushige; Yamashita, Shinzo; Matsuyama, Tomochika; Yamaoka, Hitoshi.

    1984-01-01

    Natural rubber (NR) and isoprene rubber (IR) were cured by sulfur and accelerator to give rubber vulcanizates. Both vulcanizates were subject to solvent extraction to purify them, followed by the γ-ray irradiation in air at room temperature. The deterioration by γ-ray (0-20 Mrad) was investigated by the changes of tensile properties, hardness, swelling, and ATR-IR spectra. The tensile strength decreased much by a few Mrad irradiation, which is elucidated due to the difficulty of stretch-induced crystallization of polyisoprene after the irradiation. Modulus at 50 % elongation, network-chain density, and hardness did not show significant variation with the γ-ray dose. These irradiation results suggest both degradation and crosslinking occur comparably in the rubber vulcanizates and the regularity of polyisoprene chains may be somewhat randomized to prevent them from crystallizing on stretching. (author)

  5. Behaviour of Steel Fibre Reinforced Rubberized Continuous Deep Beams

    Science.gov (United States)

    Sandeep, MS; Nagarajan, Praveen; Shashikala, A. P.

    2018-03-01

    Transfer girders and pier caps, which are in fact deep beams, are critical structural elements present in high-rise buildings and bridges respectively. During an earthquake, failure of lifeline structures like bridges and critical structural members like transfer girders will result in severe catastrophes. Ductility is the key factor that influences the resistance of any structural member against seismic action. Structural members cast using materials having higher ductility will possess higher seismic resistance. Previous research shows that concrete having rubber particles (rubcrete) possess better ductility and low density in comparison to ordinary concrete. The main hindrance to the use of rubcrete is the reduction in compressive and tensile strength of concrete due to the presence of rubber. If these undesirable properties of rubcrete can be controlled, a new cementitious composite with better ductility, seismic performance and economy can be developed. A combination of rubber particles and steel fibre has the potential to reduce the undesirable effect of rubcrete. In this paper, the effect of rubber particles and steel fibre in the behaviour of two-span continuous deep beams is studied experimentally. Based on the results, optimum proportions of steel fibre and rubber particles for getting good ductile behaviour with less reduction in collapse load is found out.

  6. Use of epoxidized natural rubber as a compatibilizer in silica-filled natural rubber tire tread compounds ; Verwendung von epoxydiertem Naturkautschuk als Verträglichkeitsvermittler in Zusammensetzungen aus kieselsäuregefülltem Naturkautschuk für Reifenlaufflächen

    NARCIS (Netherlands)

    Sengloyluan, K.; Sahakaro, Kannika; Noordermeer, Jacobus W.M.

    2012-01-01

    Silica-reinforced natural rubber (NR) tire tread compounds with epoxidized natural rubber (ENR) as a compatibilizer are investigated. ENR contents of 2.5-15.0 phr, with epoxide levels of 10, 38 and 51 mol%, are used. The addition of ENRs, especially ENR-38 and ENR-51, as compatibilizers decreases

  7. SUPPLY-CHAIN OF NATURAL RUBBER IN INDONESIA

    Directory of Open Access Journals (Sweden)

    Bustanul Arifin

    2011-08-01

    Full Text Available Normal 0 false false false MicrosoftInternetExplorer4 st1\\:*{behavior:url(#ieooui } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} The study examines the supply chain of natural rubber production in Indonesia and assessing the transmission of prices to rubber growers and provides recommendations for a suitable scheme that would help to ensure high production standards and a sustainable return for natural rubber production.  The frameworks to examine the performance of supply chain of rubber marketing rely mostly on the efficiency level of marketing system of natural rubbers, including the value chain principles in marketing margin, and revealed price transmission from consumers to growers. The results show that the roles of subdistrict middlemen are extremely crucial in moving up the slabs from the village level to urban areas, where trader-brokers are expecting the slabs to be forwarded directly to crumb-rubber factories.  Changes in world price, hence the profits being accumulated by traders and rubber factories, are not transmitted properly to rubber farmers and/or sharetappers. Information asymmetry, the access over price information, and immediate response of rubber growers to the change in world price could explain this non-cointegration in price data between growers and exporters.  In the near future, the policy reforms in supply chain of natural rubber marketing in Indonesia should carefully address these issues in a more comprehensive manner.  Finally, in order to contribute to the positive environmental and social benefits, the major challenge for natural rubber

  8. Preparation of sulfonic acid-containing rubbers from natural rubber vulcanizates

    Science.gov (United States)

    Poonsawat, Worapong; Poompradub, Sirilux; Ngamcharussrivichai, Chawalit

    2014-06-01

    In this work, a series of sulfonic acid-containing rubbers were prepared by aqueous phase oxidation of natural rubber vulcanizates in the presence of hydrogen peroxide (H2O2) and formic acid (HCOOH). The starting vulcanizates were neatly prepared via an efficient vulcanization (EV) system by varying mass ratio of N-cyclohexyl-2-benzothiazole sulfonamide (CBS), as an accelerator, to sulfur. The oxidation conditions were controlled at the molar ratio of H2O2: HCOOH = 1:1, the concentration of H2O2 = 15 wt.%, the temperature = 50 °C, and the reaction time = 3 h. The rubber materials before and after the oxidation were characterized for their physicochemical properties by using Fourier transform infrared spectroscopy, bomb calorimetry, acid-base titration and swelling measurements. The results indicated the presence of sulfonic acid group in the oxidized rubbers, generated by the oxidative cleaves of sulfide crosslinks in the rubber vulcanizates. The oxidation decreased the sulfur content of the rubber in which the level of sulfur loss was determined by the CBS/sulfur ratio. Moreover, the acidity of the oxidized products was correlated with the amount of sulfur remaining.

  9. Degradation of blending vulcanized natural rubber and nitril rubber (NR/NBR) by dimethyl ether through variation of elastomer ratio

    Science.gov (United States)

    Saputra, A. H.; Juneva, S.; Sari, T. I.; Cifriadi, A.

    2018-04-01

    Dimethyl ether can cause degradation of the rubber material seal in some applications. In order to use of natural rubber in industry, research about a blending of natural rubber (NR) and nitrile rubber (NBR) to produce rubber to meet the standard seal material application were conducted. This study will observe the degradation mechanisms that occur in the blending natural rubber and nitrile rubber (NR/NBR) by dimethyl ether. Nitrile rubber types used in this study is medium quality nitrile rubber with 33% of acrylonitrile content (NBR33). The observed parameters are percent change in mass, mechanical properties and surface morphology. This study is limited to see the effect of variation vulcanized blending ratio (NR/NBR33) against to swelling. The increase of nitrile rubber (NBR33) ratio of blending rubber vulcanized can reduce the tensile strength and elongation. The best elastomer variation was obtained after comparing with the standard feasibility material of seal is rubber vulcanized blending (NR/NBR33) with ratio 40:60 NR: NBR.

  10. Characterization of the natural rubber from new rubber tree clones of PB 300 series

    International Nuclear Information System (INIS)

    Silva, Maycon J.; Spinelli, Rafaela O.; Moreno, Rogerio M.B.; Mattoso, Luiz H.C.; Martins, Maria Alice; Scaloppi Junior, Erivaldo J.

    2015-01-01

    The natural rubber (NR) is present in more than 2500 species of plants, being the Hevea brasiliensis the most commercially exploited. It is a raw material of great importance to the Brazilian economy, but the country faces a production's deficit, having to import about 60% of its consumption. In this work , the latex obtained from rubber tree of new clones of PB series 300 (PB 311, PB 312, PB 314 , PB 326, PB 346 and PB 350 ) and RRIM 600 (control) were characterized by dry rubber content (DRC), total solids content, distribution of particle size, Zeta potential, thermogravimetry, differential scanning calorimetry, infrared in the spectroscopy (FTIR), nuclear magnetic resonance (NMR) and technological properties. The DRC values ranged from 33% to 40%, and total solids of 38% to 44%. All of the clones showed average particle diameter between 180.0 to 192.1 nm, excluding clones PB 326 and PB 346 with 150.0 nm and 157.9 nm, respectively. The NMR spectra and FTIR showed that the structure of the natural rubber from all clones studied is cis -1,4- polyisoprene. Natural rubber from the new clones showed good thermal stability up to 285 °C and glass transition temperature of -64 °C. (author)

  11. Silencing the lettuce homologs of small rubber particle protein does not influence natural rubber biosynthesis in lettuce (Lactuca sativa).

    Science.gov (United States)

    Chakrabarty, Romit; Qu, Yang; Ro, Dae-Kyun

    2015-05-01

    Natural rubber, cis-1,4-polyisoprene, is an important raw material in chemical industries, but its biosynthetic mechanism remains elusive. Natural rubber is known to be synthesized in rubber particles suspended in laticifer cells in the Brazilian rubber tree (Hevea brasiliensis). In the rubber tree, rubber elongation factor (REF) and its homolog, small rubber particle protein (SRPP), were found to be the most abundant proteins in rubber particles, and they have been implicated in natural rubber biosynthesis. As lettuce (Lactuca sativa) can synthesize natural rubber, we utilized this annual, transformable plant to examine in planta roles of the lettuce REF/SRPP homologs by RNA interference. Among eight lettuce REF/SRPP homologs identified, transcripts of two genes (LsSRPP4 and LsSRPP8) accounted for more than 90% of total transcripts of REF/SRPP homologs in lettuce latex. LsSRPP4 displays a typical primary protein sequence as other REF/SRPP, while LsSRPP8 is twice as long as LsSRPP4. These two major LsSRPP transcripts were individually and simultaneously silenced by RNA interference, and relative abundance, polymer molecular weight, and polydispersity of natural rubber were analyzed from the LsSRPP4- and LsSRPP8-silenced transgenic lettuce. Despite previous data suggesting the implications of REF/SRPP in natural rubber biosynthesis, qualitative and quantitative alterations of natural rubber could not be observed in transgenic lettuce lines. It is concluded that lettuce REF/SRPP homologs are not critically important proteins in natural rubber biosynthesis in lettuce. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Factors influencing reinforcement and NR and EPDM rubbers with short aramid fibers

    NARCIS (Netherlands)

    Sadatshirazi, S.; Noordermeer, Jacobus W.M.

    2011-01-01

    Among short fiber reinforced composites, those with rubbery matrices have gained great importance due to the advantages they have in processing and low cost, coupled with high strength. These composites combine the elastic behavior of rubbers with strength and stiffness of fibers. Aramid fibers have

  13. Maillard Reaction in Natural Rubber Latex: Characterization and Physical Properties of Solid Natural Rubber

    Directory of Open Access Journals (Sweden)

    S. Montha

    2016-01-01

    Full Text Available Maillard reaction in Natural Rubber (NR latex was investigated by treating fresh NR latex with glutaraldehyde (C5H8O2 in amounts of 0, 50, 100, and 200 mmol/kg of latex. Protein cross-linking in fresh NR latex and solid NR was confirmed by using sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE and attenuated total reflection infrared (ATR-IR spectroscopy, respectively. It was found that degree of protein cross-linking in NR increased with increasing C5H8O2 concentration. Physical properties of untreated and treated NR substances in terms of gel content, initial Wallace plasticity (P0, plasticity retention index (PRI, Mooney viscosity, and tensile strength were carefully explored. Results clearly showed that the Maillard cross-linking of proteins had remarkable effect on bulk NR properties, that is, solvent resistance, hardness, resistance to oxidation, rheological behavior, and resistance to stretching out.

  14. The water-food nexus of natural rubber production

    Science.gov (United States)

    Chiarelli, D. D.; Rosa, L.; Rulli, M. C.; D'Odorico, P.

    2017-12-01

    The increasing global demand for natural rubber (100% increase in the last 15 years) is for most part met by Malaysia and Indonesia, and - to a lesser extent - other countries in south-east Asia and Africa. The consequent expansion of rubber plantation has often occurred at the expenses of agricultural land for staple food, particularly in southeast Asia, where most of the land suitable for agriculture is already harvested for food crops or other uses. Here we investigate the extent to which the ongoing increase in rubber production is competing with the food system and affecting the livelihoods of rural communities in the areas of production and their appropriation of natural resources, such as water. We also investigate to what extent the expansion of rubber plantations is taking place through large scale land acquisitions (LSLAs) and evaluate the impacts on rural communities. Our results show how rubber production has strong environmental, social and economic impacts. Despite their ability to bring employment and increase the average income of economically disadvantaged areas, rubber plantations may threaten the local water and food security and induce a loss of rural livelihoods, particularly when the new plantations result from LSLAs that displace semi-subsistence forms of production thereby forcing the local populations to depend on global markets.

  15. Reinforcement of nitrile rubber by in situ formed zinc disorbate

    Directory of Open Access Journals (Sweden)

    2010-09-01

    Full Text Available Zinc disorbate (ZDS was in situ formed by the reaction between sorbic acid (SA and zinc oxide (ZnO in nitrile rubber (NBR. The effects of SA amount on the curing characteristics, crosslink density and mechanical properties of peroxide- cured NBR were studied. The results showed that ZDS was generated mainly during the rubber vulcanization, rather than the open mill compounding phase. The results from the crosslink density determinations showed that the formation of ZDS significantly increased the ionic bond content in the vulcanizates. In addition, the formation of ZDS greatly enhanced the mechanical properties of NBR vulcanizates. The modulus, tensile strength, tear strength and hardness were found to be increased with the loading of ZDS. Preheating the compounds before compression moulding was beneficial to the formation of ZDS, and consequently the increases in mechanical properties. At 40 parts per hundred rubber (phr of SA and 16 phr ZnO, five to six folds of tensile strength and tear strength of the neat NBR vulcanizate were achieved. Transmission electron microscopy (TEM results confirmed the nano-dispersion structure of the polymerized ZDS in the NBR matrix.

  16. Synthesis and characterization of silver nanoparticles in natural rubber

    International Nuclear Information System (INIS)

    Abu Bakar, N.H.H.; Ismail, J.; Abu Bakar, M.

    2007-01-01

    Silver nanoparticles are formed in natural rubber matrix via photo reduction of film cast from natural rubber latex (NRL) containing silver salt. The resulting NR-Ag nanocomposite is characterized using TEM, XRD and UV spectroscopic techniques. The nanoparticles, diameter ranging between 4 and 10 nm, are dispersed within distinct interfaces which correspond to the inter-particle boundaries of the NRL particles that form the matrix. The average width of the interfaces is 8 nm. X-ray diffraction (XRD) analysis confirms the nanoparticles as metallic silver of the face-centered cubic type. UV-vis absorption spectra show peaks characteristic of the surface plasmon resonance of nano-sized silver. A comparison with the results of formation of silver, obtained under similar reduction condition, in a series of matrices namely de-proteinized natural rubber latex (DNRL), NRL containing sodium dodecyl sulfate (SDS), aqueous solutions of bovain serum albumin and SDS, suggests that the protein in natural rubber is responsible for the formation of stable silver nanoparticles in the natural rubber (NR) matrix

  17. In situ reactive compatibilization of natural rubber/acrylic-bentonite composites via peroxide-induced vulcanization

    International Nuclear Information System (INIS)

    Fu, Lihua; Lei, Zhiwen; Xu, Chuanhui; Chen, Yukun

    2016-01-01

    To achieve good interfacial interaction between fillers and rubber matrix is always a hot topic in rubber reinforcing industry. In this paper, acid activated bentonite (Bt) was alkalified to be alkaline calcium-bentonite (ACBt), then acrylic acid (AA) was employed to modify ACBt to obtain acrylic-bentonite (ABt). The results of Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) illustrated that acrylate groups were chemically boned onto the surface of Bt and the layer spacing of Bt was increased. During peroxide-induced vulcanization, in situ compatibilization of ABt was realized via the reaction between the unsaturated bonds of acrylate groups on the surface of Bt and the natural rubber (NR) chains. This resulted in an enhanced cross-linked network which contributed to the improved mechanical properties of NR/ABt composites. - Highlights: • Acrylate groups were chemically boned onto the surface of bentonite. • In situ compatibilization was realized via the reaction of acrylate group and NR. • ABt particles participated in forming the NR crosslink network. • A potential reinforcing material options for “white” rubber products.

  18. In situ reactive compatibilization of natural rubber/acrylic-bentonite composites via peroxide-induced vulcanization

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Lihua; Lei, Zhiwen [Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004 (China); Xu, Chuanhui, E-mail: xuhuiyee@gxu.edu.cn [Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004 (China); Chen, Yukun, E-mail: cyk@scut.edu.cn [The Key Laboratory of Polymer Processing Engineering, Ministry of Education, China(South China University of Technology), Guangzhou, 510640 (China)

    2016-02-15

    To achieve good interfacial interaction between fillers and rubber matrix is always a hot topic in rubber reinforcing industry. In this paper, acid activated bentonite (Bt) was alkalified to be alkaline calcium-bentonite (ACBt), then acrylic acid (AA) was employed to modify ACBt to obtain acrylic-bentonite (ABt). The results of Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) illustrated that acrylate groups were chemically boned onto the surface of Bt and the layer spacing of Bt was increased. During peroxide-induced vulcanization, in situ compatibilization of ABt was realized via the reaction between the unsaturated bonds of acrylate groups on the surface of Bt and the natural rubber (NR) chains. This resulted in an enhanced cross-linked network which contributed to the improved mechanical properties of NR/ABt composites. - Highlights: • Acrylate groups were chemically boned onto the surface of bentonite. • In situ compatibilization was realized via the reaction of acrylate group and NR. • ABt particles participated in forming the NR crosslink network. • A potential reinforcing material options for “white” rubber products.

  19. Preparation and evaluation of some investigated natural and acrylonitrile rubber vulcanizations for physiotherapeutic purposes

    International Nuclear Information System (INIS)

    Helaly, F.M; El-Sawy, S.M.

    2005-01-01

    A trial was made to design and prepare rubber article that can be used to reactivate, strengthen and reinforce the hand muscles and fingers which had suffered from trouble movement.The investigated rubber article was prepared from natural and acrylonitrile rubber formulations. These formulations were processed in the form of compounds which contain significant quantities of fillers as Hisil, CaCO 3 and TiO 2 .The rheological characteristics and physicochemical properties of the vulcanizations were determined according to standard tests. It was found that it is possible to prepare the designated rubber article for the desired purpose. The test results show that the prepared rubber article has a good chemical resistant against acid, alkali, and salt. Also it possesses high resistance to deterioration and deformation. The prepared article has an ability to retain its elastic property after the action of compressive forces at 70 degree C for 24 hours.This was conformed with applied commercial hand exercise therapeutic article

  20. Effect of carbon black composition with sludge palm oil on the curing characteristic and mechanical properties of natural rubber/styrene butadiene rubber compound

    Science.gov (United States)

    Mohamed, R.; Nurazzi, N. Mohd; Huzaifah, M.

    2017-07-01

    This study was conducted to investigate the possibility of utilizing sludge palm oil (SPO) as processing oil, with various amount of carbon black as its reinforcing filler, and its effects on the curing characteristics and mechanical properties of natural rubber/styrene butadiene rubber (NR/SBR) compound. Rubber compound with fixed 15 pphr of SPO loading, and different carbon black loading from 20 to 50 pphr, was prepared using two roll mills. The cure characteristics and mechanical tests that have been conducted are the scorch and cure time analysis, tensile strength and tear strength. Scorch time (ts5) and cure time (t90) of the compound increases with the increasing carbon black loading. The mechanical properties of NR/SBR compound viz. the tensile strength, modulus at 300% strain and tear strength were also improved by the increasing carbon black loading.

  1. Carbon nanotubes as reinforcement of styrene-butadiene rubber

    International Nuclear Information System (INIS)

    De Falco, Alejandro; Goyanes, Silvia; Rubiolo, Gerardo H.; Mondragon, Inaki; Marzocca, Angel

    2007-01-01

    This study reports an easy technique to produce cured styrene-butadiene rubber (SBR)/multi-walled carbon nanotubes (MWCNT) composites with a sulphur/accelerator system at 150 deg. C. Significant improvement in Young's modulus and tensile strength were achieved by incorporating 0.66 wt% of filler without sacrificing SBR elastomer high elongation at break. A comparison with carbon black filled SBR was also made. Field emission scanning electron microscopy was used to investigate dispersion and fracture surfaces. Results indicated that the homogeneous dispersion of MWCNT throughout SBR matrix and strong interfacial adhesion between oxidized MWCNT and the matrix are responsible for the considerable enhancement of mechanical properties of the composite

  2. Application of gamma irradiation for incorporation of rubber powder in the formulations of EPDM and natural rubber

    International Nuclear Information System (INIS)

    Kiyan, Ludmila Y.P.; Parra, Duclerc Fernandes; Lugao, Ademar Benevolo

    2013-01-01

    The objective of this work was to study the behavior of the recycling of rubber burrs in form of powder, of the rubber industry from EPDM rubber powder and natural rubber with SBR. The rubber powder was irradiated and reused in rubber artifacts formulations for classical vulcanization. The processed material was irradiated using a 60 Co source in doses of 50, 100, 150 and 200 kGy and a dose rate of 5 kGy s-1 at room temperature. The radiation created devulcanization active sites for subsequent integration of the material (rubber powder) in formulations of commercial use. The processes were compared and their products characterized by analytical methods of the physical properties such as strength and elongation. Satisfactory results were found, noting a major spin-off of EPDM chain demonstrated by increased elongation

  3. Radiation processing of natural rubber and its applications

    International Nuclear Information System (INIS)

    Dahlan Hj. Mohd

    2007-01-01

    Research in natural rubber (NR) is still offering good and exciting opportunities especially in making NR into superior products and as a source for new chemicals by modification of its structure. As in the case of liquid epoxidised natural rubber acrylic (LENRA), it has been shown that it has the ability to induce the interfacial interaction between NR and polyolefin i.e. High-density polyethylene (HDPE) as demonstrated by Transmission Electron Microscopy (TEM) and small angle neutron scattering (SANS) techniques. For NR/HDPE blend, without deuteration technique, SANS was also to induce some scattering data leading to fruitful information on the interfacial interaction between the blend compositions. (author)

  4. Effects of carbon blacks with various structures on vulcanization and reinforcement of filled ethylene-propylene-diene rubber

    Directory of Open Access Journals (Sweden)

    2008-10-01

    Full Text Available The effects of carbon blacks on vulcanization and mechanical properties of filled ethylene-propylene-diene rubber (EPDM are investigated, by comparing with five types of rubber-grade carbon blacks. Curing kinetics is studied by rheometer and the results indicate that the curing characteristics are influenced by combination of surface area of carbon black and sulphur content on the filler surface, because the former one enhances the physical cross-linking and the latter one introduces the additional chemical cross-linking. Both the degree of cross-linking and cure rate increase with increasing surface area and sulphur content, whereas the optimum cure time and scorch time decrease. The reinforcing nature of the carbon black is assessed from mechanical measurements. It is suggested that the surface area of carbon blacks strongly affects the physical properties of EPDM/carbon black composites. Conductive carbon black (N472 can be used as desirable reinforcing filler due to the higher degree of cross-linking of EPDM with N472 than other EPDM/carbon black composites. The morphology and distribution of particles are studied by using scanning electron microscope. The sound reinforcing ability of N472 is also supported by scanning electron microscope due to the notable dispersibility of N472 within EPDM matrix. N472 ensures the EPDM/N472 composite the most conductive sample among the five composites.

  5. Rheological behavior of raw natural rubber coagulated by microorganisms

    Directory of Open Access Journals (Sweden)

    Zhifen Wang

    2014-01-01

    Full Text Available Tests of the strain sweep, frequency sweep and stress relaxation for raw natural rubber coagulated by microorganisms (NR-m and raw natural rubber coagulated by acid (NR-a were carried out with the use of a rubber process analyzer (RPA. The results showed that the storage torque, complex viscosity of NR-m were higher than those of NR-a while the loss factor was lower. The effect of temperature on viscosity of raw NR was studied following the Arrhenious-Frenkel-Eyring model. The viscous flow behavior of NR-m was poorer than those of NR-a. Furthermore, stress relaxation measurements of raw NR showed a longer period of relaxation for NR-m.

  6. Properties of rubber blends based on natural rubber loaded with different fillers and cured by gamma radiation

    International Nuclear Information System (INIS)

    Mohamed, R.M.

    2011-01-01

    In this investigation system styrene butadiene rubber (1502 type) and natural rubber were blended in different ratios namely, NR/SBR (0/100), NR/SBR (25/75), NR/SBR (50/50), NR/SBR (75/25) and NR/SBR (100/0). All the samples were subjected to gamma irradiation dose up to 250 kGy. The improvement in the mechanical properties, physico-mechanical properties and thermal properties was followed as a function of irradiation dose and blend ratio. The SBR /NR (50/50) blend with reasonable properties were filled with 40 p hr of Hisil (highly fined silicon), HAF carbon black (high abrasion furnace), TiO 2 titanium dioxide and clay; the reinforcing ability of these fillers was found to follow the order: Hisil > HAF carbon black > Clay > TiO 2 The effect of different kinds of enhancing agents (coagent) namely: N, N- methylene di acrylamide (MDA), trimethylol propane tri methacrylate (TMPTMA) and tetramethylol - methane tetraacrylate (TMMT) on the properties of the obtained composites as a function of irradiation dose was studied. The data obtained showed that the enhancement character of the co agents follow the order: TMMT >TMPTMA > MDA >unenhanced composites. This investigation showed also the effect of gamma irradiation on improving the above mentioned properties in the presence of filler and co agents. Moreover, radiation dose at 100 kGy is sufficient enough for obtained the desired properties. The obtaining composites can be used in many industrial applications such as radio controlled model race car tires to footwear applications; the SBR component adds the toughness while the natural rubber provides superior resilience and energy return when used in footwear.

  7. Performance of kevlar fibre-reinforced rubber composite armour against shaped-charge jet penetration

    Directory of Open Access Journals (Sweden)

    Xu-dong Zu

    Full Text Available AbstractThe protective capability of the Kevlar fibre-reinforced rubber composite armour (KFRRCA at different obliquities is studied using depth-of-penetration experiments method against a 56 mm-diameter standard-shaped charge. Efficiency factors are calculated to evaluate the protection capability of the KFRRCA at different obliquities. Meanwhile, an X-ray experiment is used to observe the deformation, fracture, and scatter of the shaped-charge jet as it penetrates the composite armour. Finally, scanning electron microscopy (SEM is used to analyse the effect of the Kevlar fibre-reinforced rubber for the composite armour to resist jet penetration. The results showed that the KFEECA can be used as additional armour, because it has excellent protection capability, and it can disturb the stability of the middle part of the shaped charge jet (SCJ obviously especially when the armour at 30°and 68° obliquities.

  8. Natural rubber/nitrile butadiene rubber/hindered phenol composites with high-damping properties

    Directory of Open Access Journals (Sweden)

    Xiuying Zhao

    2015-10-01

    Full Text Available New natural rubber (NR/nitrile butadiene rubber (NBR/hindered phenol (AO-80 composites with high-damping properties were prepared in this study. The morphological, structural, and mechanical properties were characterized by atomic force microscopy (AFM, polarized Fourier transform infrared spectrometer (FTIR, dynamic mechanical thermal analyzer (DMTA, and a tensile tester. Each composite consisted of two phases: the NR phase and the NBR/AO-80 phase. There was partial compatibility between the NR phase and the NBR/AO-80 phase, and the NR/NBR/AO-80 (50/50/20 composite exhibited a co-continuous morphology. Strain-induced crystallization occurred in the NR phase at strains higher than 200%, and strain-induced orientation appeared in the NBR/AO-80 phase with the increase of strain from 100% to 500%. The composites had a special stress–strain behavior and mechanical properties because of the simultaneous strain-induced orientation and strain-induced crystallization. In the working temperature range of a seismic isolation bearing, the composites (especially the NR/NBR/AO-80 (50/50/20 composite presented a high loss factor, high area of loss peak (TA, and high hysteresis energy. Therefore, the NR/NBR/AO-80 rubber composites are expected to have important application as a high-performance damping material for rubber bearing.

  9. Nanocomposites of natural rubber and polyaniline-modified cellulose nanofibrils

    Science.gov (United States)

    Cellulose nanofibrils (CNF) were isolated from cotton microfibrils (CM) by acid hydrolysis and coated with polyaniline (PANI) by in situ polymerization of aniline onto CNF in the presence of hydrochloride acid and ammonium peroxydisulfate to produce CNF/PANI. Nanocomposites of natural rubber (NR) re...

  10. High concentrations of natural rubber latex allergens in gloves used ...

    African Journals Online (AJOL)

    Introduction. Gloves made of natural rubber latex (NRL) are commonly used by healthcare workers because of their good qualities. However, allergic reactions to latex allergens are still commonly reported. Objective. To measure the concentrations of Hev b 1, Hev b 3, Hev b 5 and Hev b 6.02 allergens in gloves used by a ...

  11. Vulcanization Kinetics of Natural Rubber Based On Free Sulfur Determination

    Directory of Open Access Journals (Sweden)

    Abu Hasan

    2013-05-01

    Full Text Available The determination of free sulfur in the rubber vulcanizates provided significant representation of vulcanization reaction. In this research, the effects of vulcanization temperature, the mixing method of carbon black into rubber, the ingredients mixing sequence and the type of carbon black were studied on masticated and milled natural rubber in which the reaction was observed by un-reacted sulfur determination. The results showed that higher vulcanization temperature provided faster vulcanization reaction and greater reaction rate constant. Similarly, the mixing sequence of ingredient and carbon black into rubber influenced the rate of vulcanization reaction. The subsequent ingredients mixing sequence, in this case, resulted in higher vulcanization rate compared to that of the simultaneous one. However, the mixing method of carbon black into rubber brought small effect on the rate of vulcanization reaction. The type of carbon black applied was observed to influence the reaction rate of vulcanization. Smaller particle sizes of carbon black gave larger reaction rate constant. In this case, the type of carbon black N 330 gave faster vulcanization rate than that of N 660.

  12. Performance of kevlar fibre-reinforced rubber composite armour against shaped-charge jet penetration

    OpenAIRE

    Zu,Xu-dong; Huang,Zheng-xiang; Zhai,Wen

    2015-01-01

    AbstractThe protective capability of the Kevlar fibre-reinforced rubber composite armour (KFRRCA) at different obliquities is studied using depth-of-penetration experiments method against a 56 mm-diameter standard-shaped charge. Efficiency factors are calculated to evaluate the protection capability of the KFRRCA at different obliquities. Meanwhile, an X-ray experiment is used to observe the deformation, fracture, and scatter of the shaped-charge jet as it penetrates the composite armour. Fin...

  13. Mechanical and Morphological Properties of Waste Short Nylon Fibers and Nanoclay Reinforced NR/SBR Rubber Nanocomposites

    Directory of Open Access Journals (Sweden)

    Mohammad Andideh

    2013-02-01

    Full Text Available Natural rubber and styrene butadiene rubber (NR/SBR reinforced with short nylon fibers along with nanoclay (Cloisite 15A hybrid composites were prepared in an internal and a two roll-mill mixer by a three-step mixingprocess. The effects of fiber content at a constant loading of 3 wt% nanoclay were studied on the microstructure, mechanical and morphological properties of the prepared nanocomposites. The adhesion between the fiber and the rubber was enhanced by the addition of a dry bonding system consisting of resorcinol, hexamethylene tetramine and hydrated silica (HRH. The curing characteristics of the composites were determined and subsequently vulcanized at 150°C using a hot press. It was observed that the cure time and swelling index of the composites decreased while maximum torque, and cure rate increased with increasing of short fiber and nanoclay contents. Thestructure and fracture surface morphology of the nanocomposites were characterized using X-ray diffraction, scanning electron microscopy. X-ray diffraction results of nanocomposites indicated that the interlayer distance of silicate layers increased. The mechanical properties (tensile, tear strength, elongation-at-break and hardness ofnanocomposites containing virgin and waste fibers in the longitudinal direction are compared.

  14. Natural rubber latex: past, present and future in Latin America

    International Nuclear Information System (INIS)

    Lugao, A.B.; Miranda, A.; Mindrisz, A.C.; Andrade e Silva, L.G. de

    1996-01-01

    The origin of the Hevea braziliensis tree was the Amazonian region in South America, particularly the Brazilian jungle. The rubber expansion at the end of 9th century brought prosperity and determined the borders of Amazonian countries. In spite of that, the Brazilian government has failed in establishing a successful policy for improving the NR production in the jungle. However, rubber plantations were successfully introduced recently near marginal areas of the humid forest in the Amazon due to the absence of the fungus Microcyclos ulei. Both, extraction of wild rubber and plantation have a key role in the maintenance of the forest health. The market for dipping products is small but is growing very fast and is expected to follow this pattern as the sanitary conditions are improved by the health authority. The history of the Brazilian NR products industry is contemporary and is based on the policy of market protection and on the lack of investments due to extremely high interest rates. As a result, the industry was not competitive. It was concluded that, in order to cope with the future challenge, the industry is required to invest in very modern technologies to produce first class goods with international acceptance. Latin America would follow the world trend for nitrosamine and protein free products. The radiation vulcanization of natural rubber latex could prove itself as a profitable solution and not only a quality solution. It was also concluded that both wild rubber and rubber plantations in Brazil have their future coupled with the future of a regional dipping industry. Moreover, the buildup of the dipping industry will be beneficial to the protection of the humid forest and the recovery of degraded areas

  15. Study of the reinforcement of rubber styrene-butadiene with mesoporous silices by solid-state nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Sierra, Ligia; Lopez, Betty; Pena, Bibiana; Rios, Juan Esteban; Castano, Nelson

    2001-01-01

    The knowledge about the interaction rubber/filler for the rubber reinforced with carbon black of silica is important to understand the physical properties, which determine the reinforcement. This paper presents a comparative study of the interactions between styrene butadiene rubber (SBR) and silica for a silica Ultrasil type and mesoporous silica MCM-41 type prepared by different procedures, based on solid state nuclear magnetic resonance: 1H MAS NMR; 13C MAS NMR, 13C CP/MAS, 29Si MAS and 29Si CP/MAS NMR. Mesoporous silica synthesized under certain specific conditions showed better interaction with the rubber than the ultrasil VN3 silica, commonly used as a reinforcement load. Mechanical tests for the SBR vulcanised with this silica indicate an important increase for values of elongation and tearing resistance, but an increase in the vulcanization time in it is compared with the SBR vulcanise with Ultrasil

  16. Effect of gamma irradiation on the properties of natural rubber/styrene butadiene rubber blends

    Directory of Open Access Journals (Sweden)

    A.B. Moustafa

    2016-09-01

    Full Text Available Blends of natural rubber (NR with styrene butadiene rubber (SBR with varying ratios have been prepared. Vulcanization of the prepared blends has been induced by irradiation of gamma rays with varying doses up to 250 kGy. Mechanical properties, namely tensile strength, tensile modulus at 100% elongation, elongation at break have been followed up as a function of irradiation dose as well as blend composition. Physical properties, namely gel fraction and swelling number have been followed up using benzene as a solvent. Thermal measurements namely thermogravimetric analysis were carried out. The results indicated that the addition of NR has improved the properties of NR / SBR blends. Also NR/SBR blend is thermally stable than NR alone.

  17. Natural rubber/high density polyethylene/ground rubber composites vulcanized by gamma irradiation

    International Nuclear Information System (INIS)

    Shaltout, N.A.; Abou zeid, M.M.; Khalil, A.M.; El Miligy, A.A.

    2010-01-01

    Natural rubber (NR) was blended mechanically with 50 phr high density polyethylene (HDPE). the mechanical, physical and thermal properties of NR/HDPE blend and its composites with different contents of ground tire rubber (GTR) before and after exposure to gamma irradiation to various doses up to 250 kGy were studied. Also, the change in structure morphology of irradiated NR/HDPE blend as well as NR/HDPE/GTR composites was examined by scanning electron microscope (SEM). The results showed that the substitution of a part of virgin NR with GTR decreases the mechanical and physical properties but not to the extent of deterioration . However, it was found that the mechanical and physical properties were improved after gamma irradiation . Composite of NR/GTR/HDPE (75/25/50) showed good properties. Scanning electron microscope showed homogeneity between the irradiated composites ingredients.

  18. Silica Based Superhydrophobic Nanocoatings for Natural Rubber Surfaces

    Directory of Open Access Journals (Sweden)

    Veromee Kalpana Wimalasiri

    2017-01-01

    Full Text Available Silica based nonfluorinated superhydrophobic coatings for natural rubber surfaces have been developed. The coating was synthesized using nanosilica dispersion and a polychloroprene type binder as a compatibilizer. This nanocoating of silica was applied on to the surface of finished natural rubber gloves, by spray coating or dipped coating methods. The nanocoating demonstrates a water contact angle of more than 150° and sliding angle of 7°. The morphological features of the coating have been studied using scanning electron microscopy and atomic force microscopy while Fourier transform infrared spectroscopy was used to understand the nature of surface functional groups. Both imaging techniques provided evidence for the presence of nanosized particles in the coating. Coated gloves demonstrated comparable mechanical properties and significantly better alcohol resistivity when compared to those of the uncoated gloves.

  19. Analysis of the quality of the manufacture of cuffs rubber reinforced with the use of the QFD method

    Directory of Open Access Journals (Sweden)

    N. O. Savchenko

    2016-01-01

    Full Text Available The use of cuffs rubber reinforced diverse, from pipe fittings to domestic plumbing. In this regard, relevant is the development of high-quality cuffs rubber reinforced on the basis of various fillers in order to prevent leakage of the working fluid and improve the reliability of cuffs in a wide range of loads. To improve the quality of cuffs rubber reinforced and meet the requirements of consumers a fundamentally new way to strengthen the rubber, which will improve the qualitative characteristics of cuffs rubber reinforced, consequently, increase their resistance to solvents is added to a polymer filler on the basis of nanocarbon. The purpose of this study is to plan quality cuffs rubber reinforced with the use of tolerancerange filler using tools monitoring and quality management the methodology of Quality Function Deployment (QFD. The relevance of QFD method is to determine the most important issues and related priorities, especially in the choice of positions that should be solved and improved when developing new products. To achieve this goal the following tasks: conducted market analysis of rubber products; carried out a consumer benchmarking and ranking of customer requirements; based on the analysis of customer requirements to cuffs rubber reinforced identified the most important requirements and via the SFC installed priority technical characteristics for further improvements; designed new product using the QFD. QFD method allowed a large amount of information in a compressed form and identify areas to improve specific technical specifications based on customer requirements.

  20. Wood Sawdust/Natural Rubber Ecocomposites Cross-Linked by Electron Beam Irradiation

    Directory of Open Access Journals (Sweden)

    Elena Manaila

    2016-06-01

    Full Text Available The obtaining and characterization of some polymeric eco-composites based on wood sawdust and natural rubber is presented. The natural rubber was cross-linked using the electron beam irradiation. The irradiation doses were of 75, 150, 300 and 600 kGy and the concentrations of wood sawdust were of 10 and 20 phr, respectively. As a result of wood sawdust adding, the physical and mechanical properties such as hardness, modulus at 100% elongation and tensile strength, showed significant improvements. The presence of wood sawdust fibers has a reinforcing effect on natural rubber, similar or better than of mineral fillers. An increase in the irradiation dose leads to the increasing of cross-link density, which is reflected in the improvement of hardness, modulus at 100% elongation and tensile strength of blends. The cross-linking rates, appreciated using the Flory-Rehner equation, have increased with the amount of wood sawdust in blends and with the irradiation dose. Even if the gel fraction values have varied irregularly with the amount of wood sawdust and irradiation dose it was over 90% for all blends, except for the samples without wood sawdust irradiated with 75 kGy. The water uptake increased with increasing of fiber content and decreased with the irradiation dose.

  1. Preparation and mechanical properties of rubber composites reinforced with carbon nanohorns.

    Science.gov (United States)

    Isshiki, Tetsuya; Hashimoto, Mikiko; Morii, Masato; Ota, Yuki; Kaneda, Kazuo; Takahashi, Hidetaka; Yudasaka, Masako; Iijima, Sumio; Okino, Fujio

    2010-06-01

    Nitrile butadiene rubber (NBR) composites with single-wall carbon nanohorns (SWNHs, or simply NHs), hole-opened NHs (h-NHs), and carbon black (CB), the most commonly used nanocarbon rubber filler, were prepared, and their mechanical properties were compared. The NBR composites with h-NHs (NBR/h-NH) showed higher tensile strength than those with NHs (NBR/NH), and the tensile strength of NBR/h-NH or NBR/NH was much greater than those of the NBR composites with CB (NBR/CB). At 5 parts per hundred of rubber (phr), the tensile stresses at break of NBR/h-NH was about 1.8 times larger than those of NBR/CB, and the strain at the break, 1.2 times larger. Similarly, at 20 phr, both the tensile strength and strain at the break of NBR/h-NH were 1.4 times larger than those of NBR/CB. NBR/NH showed the highest hardness while having the smallest specific gravity. The present results indicate that NHs and h-NHs have much superior reinforcement effects to CB for NBR rubber matrix.

  2. The influence of temperature and reaction time in the degradation of natural rubber latex

    International Nuclear Information System (INIS)

    Siti Zaleha Isa; Rosiyah Yahya; Aziz Hassan; Mohd Tahir

    2007-01-01

    Liquid natural rubber (LNR /LENR) should be considered as a new material instead of a new type of rubber though they have the same configuration as the rubber used. In this work, thermal degradation of natural rubber latex was carried out to obtain LNR/LENR by varying the reaction time at different temperatures. The degraded polymers were characterized structurally using FTIR and NMR spectroscopies and the average molecular weights were determined by membrane-osmometry and viscometry. (author)

  3. Radiation vulcanised natural rubber latex (RVNRL) market and challenges

    International Nuclear Information System (INIS)

    Wan Manshol Wan Zin; Najib Mohamad Zakey; Chai Chee Keong

    2000-01-01

    RVNRL has the required properties and proven useful for the manufacturing of examination gloves, balloons and finger cots at industrial scale. To date only RVNRL finger cots are available in the market. Problems and challenges for the market of other products are identified. Further success in the on going research activities will be the reference for more applications of RVNRL in the relevant industry to produce natural rubber latex products of more competitive values

  4. Application of radiation vulcanized natural rubber latex in Indonesia

    International Nuclear Information System (INIS)

    Soebianto, Y.S.; Wiwik Sofiarti; Razzak, M.T.

    1996-01-01

    The center has carried out R and D of Radiation Vulcanization Natural Rubber Latex (RVNRL) technology and introduced it to the industries since the inauguration and operation of the latex pilot plant in 1983. After years of experiences and the environmental consideration, n-butylacrylate (n-BA) has replaced CCI, as the sensitizer. Until now the introduction program shows that radiation vulcanized latex is more suitable for home industries than large industries. The obstacle of the program is the marketing of the dipped products. In spite of these problems, the introduction of this technology to the people in some undeveloped area of Java has supported the national program to improve their living standard. The problems of nitrosamine and protein allergic have turn up RVNRL to be the substitute of sulfur vulcanized latex in the future. The cooperation with a national condom manufacturer (PT Mitra Banjaran) has applied RVNRL for condom production in the large scale. Soft condoms with less probability of pinhole are obtained, but the technical problem is stickiness after pilling. Supply to a baby teat and a rubber thread manufacturer offers great advantages by not using any chemicals. In spite of the advantages, the problem of latex viscosity for dipping and the low modulus of elasticity of the threads arise. Through those input CAIR-BATAN is conducting the research and development in improving the crosslinking among the rubber particles that are supposed to be the reason of the stickiness and low modulus of elasticity. This effort is expected to be able to broaden the application of RVNRL, and it will be achieved only by the involvement of rubber chemist, rubber technologist, and radiation chemist

  5. Physicomechanical properties of nanocomposites based on cellulose nanofibre and natural rubber latex

    CSIR Research Space (South Africa)

    Abraham, E

    2012-11-01

    Full Text Available and tensile strength was observed as a result of addition of CNF to the rubber matrix especially at higher CNF loading. DMA showed a change in the storage modulus of the rubber matrix upon addition of CNF which proves the reinforcing effect of CNF in the NR...

  6. Modification of (DGEBA epoxy resin with maleated depolymerised natural rubber

    Directory of Open Access Journals (Sweden)

    2008-04-01

    Full Text Available In this work, diglycidyl ether of bisphenol A (DEGBA type epoxy resin has been modified with maleated depolymerised natural rubber (MDPR. MDPR was prepared by grafting maleic anhydride onto depolymerised natural rubber. MDPR has been characterized by Fourier transform infrared (FT-IR spectroscopy and nuclear magnetic resonance spectroscopy. MDPR was blended with epoxy resin at three different ratios (97/3, 98/2 and 99/1, by keeping the epoxy resin component as the major phase and maleated depolymerised natural rubber component as the minor phase. The reaction between the two blend components took place between the acid/anhydride group in the MDPR and the epoxide group of the epoxy resin. The proposed reaction schemes were supported by the FT-IR spectrum of the uncured Epoxy/MDPR blends. The neat epoxy resin and Epoxy/MDPR blends were cured by methylene dianiline (DDM at 100°C for three hours. Thermal, morphological and mechanical properties of the neat epoxy and the blends were investigated. Free volume studies of the cured, neat epoxy and Epoxy/MDPR blends were correlated with the morphological and mechanical properties of the same systems using Positron Annihilation Lifetime Studies.

  7. Progress in radiation vulcanization of natural rubber latex

    International Nuclear Information System (INIS)

    Makuuchi, Keizo

    2000-01-01

    Vulcanization dose defined as the radiation dose at which cross-linked natural rubber in latex has the maximum tensile strength can be reduced by adding carbon tetrachloride as a reaction accelerator. The radiation vulcanization of natural rubber latex was selected as one of regional projects of IAEA in 1989 and a pilot plant was built in Jakarta. The products from it were evaluated during 1983-1985, followed by IAEA decision to support the continued R and D study at Takasaki, JAERI. Various factors to improve the properties of the products have been studied. Several advantages of the process over conventional method, such as absence of N-nitrosoamines, low cytotoxicity, decomposability in the environment, transparency and softness, were confirmed. The technology has been transferred toward commercial application in Thailand, and pilot plants being set up in Indonesia, India, Malaysia and Thailand. Moreover, the process was found to be effective in reducing protein remaining in natural rubber latex products and the initial investment and irradiation cost was found to be greatly reduced by employing low energy electron accelerator. This paper reviews such progress. (S. Ohno)

  8. Extractable proteins from field radiation vulcanized natural rubber latex

    Energy Technology Data Exchange (ETDEWEB)

    Parra, Duclerc F. [Chemical and Environmental Centre, Nuclear Energy Research Institute, Av. Lineu Prestes, 2242-CEP Sao Paulo (Brazil)]. E-mail: dfparra@ipen.br; Pinto Martins, Carlos Felipe [Chemical and Environmental Centre, Nuclear Energy Research Institute, Av. Lineu Prestes, 2242-CEP Sao Paulo (Brazil); Collantes, Hugo D.C. [Chemical and Environmental Centre, Nuclear Energy Research Institute, Av. Lineu Prestes, 2242-CEP Sao Paulo (Brazil); Lugao, Ademar B. [Chemical and Environmental Centre, Nuclear Energy Research Institute, Av. Lineu Prestes, 2242-CEP Sao Paulo (Brazil)

    2005-07-01

    The type I allergy associated with the use of natural rubber latex (NRL) products is caused by the NRL proteins leached by the sweat or other body fluids. Makuuchi's group proposed for the first time the proteins removal by the addition of water-soluble polymers (WSP) on radiation vulcanization of natural rubber latex (RVNRL) that is a promising process under development in many countries. In this study, Brazilian field natural rubber was irradiated with a {sup 60}Co gamma source to reduce the content of WSP in the final product. WSP was used as additive to improve the extraction of protein. After irradiation the RVNRL was centrifuged to extract the WSP and proteins. The analytical methodology for protein content was based on the modified Lowry method according to ASTM D5712. Protein determination was carried out in serum of latex and in the extracts of the gloves. The concentration of extractable water-soluble proteins in serum of irradiated field NRL (NRL1), not irradiated one (NRL2); of twice centrifuged sample with polymer additive NRL (NRL3) and of the glove manufactured (NRLG) are compared with commercial glove (CG). The irradiation process increases the extractable water-soluble proteins, EP, as reported in the literature. In this study the use of polymeric additive on the bi-centrifugation process to remove protein was successful and the EP of the glove obtained in NRL3 was at around 40% of the commercial glove.

  9. Effect of synthesized zinc stearate on the properties of natural rubber vulcanizates in the absence and presence of some fillers

    International Nuclear Information System (INIS)

    Helaly, F.M.; El Sabbagh, S.H.; El Kinawy, O.S.; El Sawy, S.M.

    2011-01-01

    Research highlights: → The mechanical properties of NR were enhanced through partial and complete replacement of zinc stearate. → The effect of adding different concentrations of zinc stearate on the physic-mechanical and SEM properties has been investigated. → Zinc stearate was found to play dual role, it reinforces the matrix blow its melting point and higher temperature it plasticizers the system. → Zinc stearate can be used as activator for sulfur vulcanization process of rubber instead of ZnO and stearic acid; in absence and presence of fillers. -- Abstract: Zinc stearate was synthesized by precipitation method through two steps; neutralization of stearic acid by sodium hydroxide then double decomposition using zinc sulphate to precipitate zinc stearate. Mass balances of the two steps were calculated and the physical properties of the prepared zinc stearate were measured and compared to standard. It was characterized and incorporated it into natural rubber in the absence and presence of some filler through mixing process of rubber. The vulcanization process was carried out at 142 o C. The rheological properties of natural rubber mixes were measured using oscillating disc rheometer. The plysico-mechanical properties of the vulcanizates were determined using tensile testing machine. It was found that, partial and complete replacement of synthesized zinc stearate instead of the conventional zinc oxide and stearic acid; enhanced the physico-mechanical properties of natural rubber. The measured reinforcing parameter value α f can be arranged according to the type of filler as follows: HAF>Hisil>CaCO 3 >Ca 3 (PO 4 ) 2 >BaSO 4 >Talc The highest value of α f represents the strength of filler and consequently the reinforcing effect of carbon black (HAF) filler while the lowest value of α f was observed for Talc which show moderate reinforcing effect of Talc. The scanning electron microscope study showed high surface homogenity and good dispersion of zinc

  10. Feasibility of Steel Fiber-Reinforced Rubberized Concrete in Cold Regions for High Volume Intersections

    Science.gov (United States)

    Abou Eid, Mahear A.

    There are many challenges faced with the use of Portland Cement Concrete (PCC) in cold regions, but with the inclusion of new technologies such as steel fibers and recycled tire crumb rubber efficient construction may be possible. Research was conducted on a modified concrete material that included both steel fibers and crumb rubber. The composite material was called Steel Fiber-Reinforced Rubberized Concrete (SFRRC). The objective of this investigation was to provide evidence showing that SFRRC can reduce tire rutting compared to asphaltic pavement. In addition, the research showed that the SFRRC could withstand freeze-thaw cycles and increase service life of roadways. Several tests were performed to determine the characteristics of the material. Freeze-thaw testing was performed to determine compressive strength loss and visual deterioration of the material. Wheel tracker rut testing was performed both with the standard steel wheel and with a modified studded rubber tire to determine plastic deformation and rut resistance. An experimental test slab was cast in place on a public approach to observe the construction procedures, the effects of studded tire wear and the frost actions in cold region conditions. Based on freeze-thaw and wheel tracker test results and observations of the experimental test slab, the SFRRC material shows viability in cold regions for resisting freeze-thaw actions. The freeze-thaw testing resulted in increased compressive strength after 300 freeze-thaw cycles and very low deterioration of material compared to standard PCC. The wheel tracker testing resulted in very low plastic deformation and minor material rutting with use of the studded rubber tire. The test slab showed very minor surface wear, no freeze-thaw cracking and no rutting after one winter of use. It is recommended that further testing of the material be conducted by means of a large-scale trial section. This would provide information with respect to cost analysis and

  11. Dynamic Properties and Fatigue Life of Stone Mastic Asphalt Mixtures Reinforced with Waste Tyre Rubber

    Directory of Open Access Journals (Sweden)

    Nuha Salim Mashaan

    2013-01-01

    Full Text Available Today, virgin polymer modified asphalt mixes are comparatively more expensive for road pavement. One way to reduce the expense of such construction and to make it more convenient is the application of inexpensive polymer, such as waste polymer. The primary aim of this study was to investigate the effect of adding waste tyre rubber (crumb rubber modifier (CRM on the stiffness and fatigue properties of stone mastic asphalt (SMA mixtures. Various percentages of waste CRM with size of 0.60 mm were added to SMA mixtures. Indirect tensile stiffness modulus test was conducted at temperatures of 5, 25, and 40°C. Indirect tensile fatigue test was conducted at three different stress levels (2000, 2500, and 3000 N. The results show that the stiffness modulus of reinforced SMA samples containing various contents of CRM is significantly high in comparison with that of nonreinforced samples, and the stiffness modulus of reinforced samples is in fact less severely affected by the increased temperature compared to the nonreinforced samples. Further, the results show that CRM reinforced SMA mixtures exhibit significantly higher fatigue lives compared to the nonreinforced mixtures help in and promotion of sustainable technology by recycling of waste materials in much economical and environmental-friendly manner.

  12. The role of carbon nanotubes in promoting the properties of carbon black-filled natural rubber/butadiene rubber composites

    Directory of Open Access Journals (Sweden)

    Jiangshan Gao

    Full Text Available 80/20 natural rubber (NR/butadiene rubber (BR blends in which the carbon black (CB was replaced partially by multi-walled carbon nanotubes (MWCNTs according to the ratios m (CNTs: m (decreasing amount of CB = 1: X (X was varied from 1 to 6, was prepared by blending of internal mixer and the two-roll mill at the mill opening of 0.5 mm for 10 times. SEM and TEM were used to investigate the filler networks and the good dispersion of fillers. The compounds containing 5 phr CNTs/27.5 phr CB exhibited the best abrasion resistance which was increased by 12.69% compared that without CNTs. 3D morphology images of wear surfaces and tensile fracture surfaces being similar to the layered map of the geography, which match the abrasion resistance and tensile properties, were observed by 3D measuring laser microscope. The uncured blend with 5 phr CNTs/35 phr CB showed the shortest cure time, the highest modulus and level of crosslink density. Significant improvement in mechanical properties were achieved by incorporating 5 phr CNTs and 35 phr CB, and the tear strength, 100% and 300% modulus of the vulcanizate were enhanced by 36.36%, 61.29% and 31.63% compared with the composite with 0 phr CNTs/40 phr CB, respectively. Additionally, compared with the composite without CNTs, the thermal conductivity of the composites with 5 phr CNTs/35 phr CB is increased by an average of 6.15% at three different temperatures. These considerable reinforcements resulted from the synergistic effect of CNTs and CB. Keywords: Synergistic effect, Carbon nanotubes, DIN abrasion, Mechanical properties, Thermal conductivity, 3D measuring laser microscope

  13. The role of natural rubber in seismic isolation - a perspective

    International Nuclear Information System (INIS)

    Coveney, V.A.

    1991-01-01

    The ''base-isolation'' technique for protecting buildings against earthquakes is based on the fundamental physics of systems in oscillation. It relies on lowering the natural frequency of the building/support system below that of the major frequencies present in the earthquake. Although simple in concept, many years of development have been required to convert it into a practical, reliable system. Seen fifteen years ago as an eccentric dream, base isolation is today recognized as the only feasible method of protecting some buildings and their contents, and as an attractive option for a widening range of other types. In most practical systems, natural rubber has an essential role. (orig.) [de

  14. Thermomechanical analysis of Natural Rubber behaviour stressed at room temperature.

    Directory of Open Access Journals (Sweden)

    Chrysochoos A.

    2010-06-01

    Full Text Available Owing to their high molecular mobility, stressed rubber chains can easily change their conformations and get orientated. This phenomena leads to so high reversible draw ratio that this behaviour is called rubber elasticity [1-3]. The analogy with ideal gases leads to an internal energy independent of elongation, the stress being attributed to a so-called configuration entropy. However, this analysis cannot take thermal expansion into account and moreover prohibits predicting standard thermo-elastic effect noticed at small elongations and the thermoelastic inversion effects [4]. This paper aims at : observing and quantifying dissipative and coupling effects associated with deformation energy, generated when Natural Rubber is stretched. re-examine the thermomechanical behaviour model of rubberlike materials, under the generalised standard material concept. From an experimental viewpoint, energy balance is created using infrared and quantitative imaging techniques. Digital Image Correlation (DIC provides in-the-plane displacement fields and, after derivation, strain and strain-rate fields. We have used those techniques to evidence the thermoelastic inversion effect as shown on Figure 1 where different weights have been fixed to warmed specimen and we monitored the sample deformation while it recovers room temperature. But we have also used those techniques to perform energy balance : analysis of the mechanical equilibrium allows estimates of the stress pattern and computation of deformation energy rates under a plane stress hypothesis [5]. Infrared Thermography (IRT gives the surface temperature of the sample. To estimate the distribution of heat sources, image processing with a local heat equation and a minimal set of approximation functions (image filtering was used. The time courses of deformation energy and heat associated with cyclic process are plotted in Figure 2. The time derivatives of both forms of energy are approximately similar. This

  15. Reinforcement of Multiwalled Carbon Nanotube in Nitrile Rubber: In Comparison with Carbon Black, Conductive Carbon Black, and Precipitated Silica

    Directory of Open Access Journals (Sweden)

    Atip Boonbumrung

    2016-01-01

    Full Text Available The properties of nitrile rubber (NBR reinforced by multiwalled carbon nanotube (MWCNT, conductive carbon black (CCB, carbon black (CB, and precipitated silica (PSi were investigated via viscoelastic behavior, bound rubber content, electrical properties, cross-link density, and mechanical properties. The filler content was varied from 0 to 15 phr. MWCNT shows the greatest magnitude of reinforcement considered in terms of tensile strength, modulus, hardness, and abrasion resistance followed by CCB, CB, and PSi. The MWCNT filled system also exhibits extremely high levels of filler network and trapped rubber even at relatively low loading (5 phr leading to high electrical properties and poor dynamic mechanical properties. Although CCB possesses the highest specific surface area, it gives lower level of filler network than MWCNT and also gives the highest elongation at break among all fillers. Both CB and PSi show comparable degree of reinforcement which is considerably lower than CCB and MWCNT.

  16. Preparation and Characterisation of Crosslinked Natural Rubber (SMR CV 60 and Epoxidised Natural Rubber (ENR-50 Blends

    Directory of Open Access Journals (Sweden)

    M. SASITARAN

    2018-04-01

    Full Text Available In this sudy, the influenceof di(tert-butylperoxyisopropylbenzene (DTBPIB on the properties of natural rubber (NR blend with epoxidized natural rubber (ENR was determined. Fourier transform infrared spectroscopy with attenuated total refletance analysis and gel content confired crosslinking occurred in the rubber blends in the presence of peroxide DTBPIB percentage. Studies including tensile properties, dynamic mechanical properties, thermogravimetric analysis (TGA and water absorptivity showed the changes in properties of the crosslinked NR/ENR blends. Tensile properties analysis disclosed the improvements in the modulus at 300% elongation and tensile stength with increasing NR ratios. Dynamic mechanical analysis revealed the blends to be incompatible and immiscible, with ENR showing a more viscous behaviour compared to the polymer blends. Thermal properties improved by blending NR with ENR as the onset temperature of NR/ENR: 50/50 was higher than pure NR by approximately 10oC and ENR by approximately 2oC. Water absorptivity experiment revealed a two-fold reduction in the presence of crosslinking for all blend ratios.

  17. Radiation degradation of methyl methacrylate grafted natural rubber

    International Nuclear Information System (INIS)

    Perera, M.C.S.

    1998-01-01

    M G rubber is a mixture consisting of the graft copolymer and two home polymers. Natural rubber is known to undergo crosslinking during exposure to high energy radiation where as poly methyl methacrylate is a polymer where high energy radiation causes chain scission. It is interesting to determine how this partially miscible blend of scission and crosslinking polymers will behave under high energy radiation. Dynamic Mechanical Analysis (DMA) was used to study the variations in the glass transition regions during high energy treatment of the polymers. Another techniques that is available to obtain motional information and miscibility of blends is Nuclear Magnetic Resonance Spectroscopy (NMR).The present study is aimed at understanding the changes in the molecular structure of rubber when exposed to high energy radiation. The changes in the dynamic mechanical properties in the glass transition region and solid state NMR were made used of for this investigation. The data obtained from the DMA results were analysed to calculate the radiation chemical yields. The local dynamics were investigated with measurement of carbon relaxation times and molecular structure was studied with focus on the level of intermolecular mixing by proton relaxation times

  18. Silver nanoparticles delivery system based on natural rubber latex membranes

    International Nuclear Information System (INIS)

    Guidelli, Éder José; Kinoshita, Angela; Ramos, Ana Paula; Baffa, Oswaldo

    2013-01-01

    The search for new materials for biomedical applications is extremely important. Here, we present results on the performance of a silver nanoparticles delivery system using natural rubber latex (NRL) as the polymeric matrix. Our aim was to obtain an optimized wound dressing by combining materials with potential healing action. The synthesis of silver nanoparticles and their characterization by UV–Vis spectroscopy, transmission electron microscopy, zeta potential, dynamic light scattering, and Fourier transform infrared spectroscopy (FTIR) are depicted. The NRL membranes are good matrix for silver nanoparticles and allow for their gradual release. The release of 30 nm silver nanoparticles by the NRL membranes depends on their mass percentage in NRL membranes. The total concentration of AgNP released by the NRL membranes was calculated. The AgNP attached to the cis-isoprene molecules in the NRL matrix remain attached to the membrane (∼0.1 % w/w). So, only the AgNP bound to the non-rubber molecules are released. FTIR spectra suggest that non-rubber molecules, like aminoacids and proteins, associated with the serum fraction of the NRL may be attached to the surfaces of the released nanoparticles, thereby increasing the release of such molecules. The released silver nanoparticles are sterically stabilized, more stable and well dispersed. Because the serum fraction of the NRL is responsible for the angiogenic properties of the matrix, the silver nanoparticles could increment the angiogenic properties of NRL. This biomaterial has desirable properties for the fabrication of a wound dressing with potential healing action, since it combines the angiogenic and antibacterial properties of the silver nanoparticles with the increased angiogenic properties of the NRL.Graphical AbstractThe AgNP attached to the cis-isoprene molecules remain in the NRL matrix and only the AgNP bound to the non-rubber molecules (NRL serum fraction) are released. The released AgNP are sterically

  19. Silver nanoparticles delivery system based on natural rubber latex membranes

    Energy Technology Data Exchange (ETDEWEB)

    Guidelli, Eder Jose, E-mail: ederguidelli@gmail.com [Universidade de Sao Paulo/FFCLRP-DF (Brazil); Kinoshita, Angela [Universidade do Sagrado Coracao (Brazil); Ramos, Ana Paula [Universidade de Sao Paulo/FFCLRP-DQ (Brazil); Baffa, Oswaldo [Universidade de Sao Paulo/FFCLRP-DF (Brazil)

    2013-04-15

    The search for new materials for biomedical applications is extremely important. Here, we present results on the performance of a silver nanoparticles delivery system using natural rubber latex (NRL) as the polymeric matrix. Our aim was to obtain an optimized wound dressing by combining materials with potential healing action. The synthesis of silver nanoparticles and their characterization by UV-Vis spectroscopy, transmission electron microscopy, zeta potential, dynamic light scattering, and Fourier transform infrared spectroscopy (FTIR) are depicted. The NRL membranes are good matrix for silver nanoparticles and allow for their gradual release. The release of 30 nm silver nanoparticles by the NRL membranes depends on their mass percentage in NRL membranes. The total concentration of AgNP released by the NRL membranes was calculated. The AgNP attached to the cis-isoprene molecules in the NRL matrix remain attached to the membrane ({approx}0.1 % w/w). So, only the AgNP bound to the non-rubber molecules are released. FTIR spectra suggest that non-rubber molecules, like aminoacids and proteins, associated with the serum fraction of the NRL may be attached to the surfaces of the released nanoparticles, thereby increasing the release of such molecules. The released silver nanoparticles are sterically stabilized, more stable and well dispersed. Because the serum fraction of the NRL is responsible for the angiogenic properties of the matrix, the silver nanoparticles could increment the angiogenic properties of NRL. This biomaterial has desirable properties for the fabrication of a wound dressing with potential healing action, since it combines the angiogenic and antibacterial properties of the silver nanoparticles with the increased angiogenic properties of the NRL.Graphical AbstractThe AgNP attached to the cis-isoprene molecules remain in the NRL matrix and only the AgNP bound to the non-rubber molecules (NRL serum fraction) are released. The released AgNP are

  20. Study on grafting of different types of acrylic monomers onto natural rubber by γ-rays

    International Nuclear Information System (INIS)

    Dafader, N.C.; Haque, M.E.; Akhtar, F.; Ahmad, M.U.

    2006-01-01

    A comparative study of various acrylic monomers for grafting onto natural rubber was done. The stability of natural rubber latex (NRL) against coagulum with monomer, mechanical properties of grafted rubbers and percent of grafting were investigated. The NRL with monomers, methylacrylate (MA), ethylacrylate (EA) and n-butylacrylate (n-BA), is unstable but it is stable with methyl methacrylate (MMA), n-butyl methacrylate (BMA) and cyclohexyl methacrylate (CHMA). The mechanical properties and degree of grafting attained a maximum at a total radiation dose of 4 kGy. The values of tensile properties of MMA and CHMA grafted rubbers are almost similar, and higher than those of BMA grafted rubbers. On the other hand, the degree of grafting for CHMA is higher than those of MMA and BMA grafted rubbers. The infrared (IR) spectra of monomer grafted natural rubber were also studied

  1. Tear energy and strain-induced crystallization of natural rubber/styrene-butadiene rubber blend

    International Nuclear Information System (INIS)

    Noguchi, F; Akabori, K; Yamamoto, Y; Kawahara, S; Kawazura, T

    2009-01-01

    Strain-induced crystallization of natural rubber (NR), dispersed in styrene-butadiene rubber (SBR), was investigated in relation to dimensional feature of a dispersoid and crosslink density of NR by measuring tear energy (G) of crosslinked NR/SBR blends. The crosslinked NR/SBR blends in ratios of 1/9 and 3/7 by weight were prepared by mixing masticated NR and SBR with an internal mixer at a rotor speed of 30 rpm, followed by crosslinking with dicumyl peroxide on a hot press at 444 K for 60 min. The G, measured in wide-ranges of temperature and tear rate, was superposed into a master curve with a Williams-Landel-Ferry shift factor. The G of the NR/SBR(3/7) blend abruptly decreased to a level comparable to that of SBR at about melting temperature of NR crystals formed on straining. The temperature, at which the dramatic decrease in the G occurred, was associated with the dimensional feature of the NR dispersoid and the crosslink density.

  2. About the cure kinetics in natural rubber/styrene Butadiene rubber blends at 433 K

    International Nuclear Information System (INIS)

    Mansilla, M.A.; Marzocca, A.J.

    2012-01-01

    Vulcanized blends of elastomers are employed in several goods mainly to improve physical properties and reduce costs. One of the most used blends of this kind is that composed by natural rubber (NR) and styrene butadiene rubber (SBR). The cure kinetic of these blends depends mainly on the compound formulation and the cure temperature and time. The preparation method of the blends can influence the mechanical properties of the vulcanized compounds. In this work the cure kinetic at 433 K of NR/SBR blends vulcanized with the system sulfur/TBBS (N-t-butyl-2-benzothiazole sulfenamide) is analyzed in samples prepared by mechanical mixing and solution blending. The two methods produce elastomer domains of NR and SBR, which present different microstructure due to the cure level attained during vulcanization. The cure kinetics is studied by means of rheometer tests and the model proposed by Kamal and Sourour. The analysis of the cure rate is presented and is related to the structure obtained during the vulcanization process.

  3. About the cure kinetics in natural rubber/styrene Butadiene rubber blends at 433 K

    Energy Technology Data Exchange (ETDEWEB)

    Mansilla, M.A., E-mail: mmansilla@df.uba.ar [Laboratorio de Polimeros y Materiales Compuestos, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellon 1, C1428EGA Buenos Aires (Argentina); Marzocca, A.J. [Laboratorio de Polimeros y Materiales Compuestos, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellon 1, C1428EGA Buenos Aires (Argentina)

    2012-08-15

    Vulcanized blends of elastomers are employed in several goods mainly to improve physical properties and reduce costs. One of the most used blends of this kind is that composed by natural rubber (NR) and styrene butadiene rubber (SBR). The cure kinetic of these blends depends mainly on the compound formulation and the cure temperature and time. The preparation method of the blends can influence the mechanical properties of the vulcanized compounds. In this work the cure kinetic at 433 K of NR/SBR blends vulcanized with the system sulfur/TBBS (N-t-butyl-2-benzothiazole sulfenamide) is analyzed in samples prepared by mechanical mixing and solution blending. The two methods produce elastomer domains of NR and SBR, which present different microstructure due to the cure level attained during vulcanization. The cure kinetics is studied by means of rheometer tests and the model proposed by Kamal and Sourour. The analysis of the cure rate is presented and is related to the structure obtained during the vulcanization process.

  4. Preparation of highly stabilised natural rubber latex for radiation vulcanisation

    International Nuclear Information System (INIS)

    Kulatunge, S.S.; Nadarajah, M.; Kalyani, N.M.V.; Chandralal, H.N.K.K.; Devendra, R.

    1996-01-01

    There is a bright future for radiation vulcanised natural rubber latex (RVNRL) but there are problems in manufacturing it as the centrifuged latex to be used for radiation has to be kept for at least a month or sometimes even three to six months before adding the sensitisers and even then the latex sometimes coagulates on adding the sensitisers. This paper describes a process by which the latex can be stabilised by addition of an anionic soap before centrifuging so that it has a high mechanical stability and hence can be used even within one week of the manufacture of the centrifuged latex

  5. Properties of Natural Rubber-Based Composites Containing Fullerene

    Directory of Open Access Journals (Sweden)

    Omar A. Al-Hartomy

    2012-01-01

    Full Text Available In this study the influence of fullerenes in concentrations from 0.5 to 1.5 phr on both the vulcanization characteristics of the compounds and physicomechanical, dynamic, and dielectric properties and thermal aging resistance of nanocomposites on the basis of natural rubber has been investigated. The effect of the filler dispersion in the elastomeric matrix has been also investigated. Neat fullerene and the composites comprising it have been studied and characterized by scanning electron microscopy (SEM and transmission electron microscopy (TEM.

  6. Radiation vulcanization of natural rubber latex with low energy accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Haque, Emdadul; Makuuchi, Keizo; Ikeda, Kenichi; Yoshii, Fumio; Kume Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Mitomo, Hiroshi [Gunma Univ., Faculty of Engineering, Department of Biological and Chemical Engineering, Kiryu, Gunma (Japan)

    2001-03-01

    The radiation vulcanization of natural rubber latex (RVNRL) with the recently installed electron beam (EB) pilot plant at Takasaki Radiation Chemistry Research Establishment, Takasaki, Japan has been discussed. The accelerating voltage and beam current of the plant are 250 kV and 10 mA respectively. The plant has a reaction vessel with the capacity of 18 liters latex to irradiate at a time. In order to obtain a suitable setting of experimental for RVNRL under EB of the plant the parameters such as irradiation time, defoamer concentration, volume of latex, beam current etc. are being optimized by varying the individual parameter at a constant set of the other variables. (author)

  7. Electron linear accelerator system for natural rubber vulcanization

    Science.gov (United States)

    Rimjaem, S.; Kongmon, E.; Rhodes, M. W.; Saisut, J.; Thongbai, C.

    2017-09-01

    Development of an electron accelerator system, beam diagnostic instruments, an irradiation apparatus and electron beam processing methodology for natural rubber vulcanization is underway at the Plasma and Beam Physics Research Facility, Chiang Mai University, Thailand. The project is carried out with the aims to improve the qualities of natural rubber products. The system consists of a DC thermionic electron gun, 5-cell standing-wave radio-frequency (RF) linear accelerator (linac) with side-coupling cavities and an electron beam irradiation apparatus. This system is used to produce electron beams with an adjustable energy between 0.5 and 4 MeV and a pulse current of 10-100 mA at a pulse repetition rate of 20-400 Hz. An average absorbed dose between 160 and 640 Gy is expected to be archived for 4 MeV electron beam when the accelerator is operated at 400 Hz. The research activities focus firstly on assembling of the accelerator system, study on accelerator properties and electron beam dynamic simulations. The resonant frequency of the RF linac in π/2 operating mode is 2996.82 MHz for the operating temperature of 35 °C. The beam dynamic simulations were conducted by using the code ASTRA. Simulation results suggest that electron beams with an average energy of 4.002 MeV can be obtained when the linac accelerating gradient is 41.7 MV/m. The rms transverse beam size and normalized rms transverse emittance at the linac exit are 0.91 mm and 10.48 π mm·mrad, respectively. This information can then be used as the input data for Monte Carlo simulations to estimate the electron beam penetration depth and dose distribution in the natural rubber latex. The study results from this research will be used to define optimal conditions for natural rubber vulcanization with different electron beam energies and doses. This is very useful for development of future practical industrial accelerator units.

  8. Multiwall carbon nanotube-filled natural rubber: Electrical and mechanical properties

    Directory of Open Access Journals (Sweden)

    L. Bokobza

    2012-03-01

    Full Text Available The influence of multiwall carbon nanotube (MWNTs contents on electrical and mechanical properties of MWNTs-reinforced natural rubber (NR composites is studied. The volume resistivity of the composites decreases with increasing the MWNTs content and the electrical percolation threshold is reached at less than 1 phr of MWNTs (phr = parts of filler by weight per hundred parts of rubber. This is caused by the formation of conductive chains in the composites. Electrical measurements under uniaxial deformation of a composite carried out at a filler loading above the percolation threshold, indicate a gradual disconnection of the conducting network with the bulk deformation. The drop in the storage modulus G' with the shear strain amplitude (Payne effect is also attributed to a breakdown of the filler network. Considerable improvement in the stiffness is obtained upon incorporation of MWNTs in the polymer matrix but the main factor for reinforcement of NR by MWNTs appears to be their high aspect ratio rather than strong interfacial interaction with rubber. The tensile strength and the elongation at break of the composites are reduced with regard to the unfilled sample. This is probably due to the presence of some agglomerates that increase with the nanotube content. This hypothesis is confirmed by a cyclic loading of the composites where it is seen that the deformation at break occurs at a much higher level of strain in the second stretch than in the first one. The overall significant property improvements are the result of a better nanotube dispersion attributed to the combined use of tip sonication and cyclohexane as dispersion aids during composite processing.

  9. Effect of gamma radiation dose and sensitizer on the physical properties of irradiated natural rubber latex

    International Nuclear Information System (INIS)

    Komgrit, R.; Thawat, C.; B, Tripob; Wirach, T.

    2009-07-01

    Full text: The vulcanization of natural rubber latex can be induced by gamma radiation, which enhances cross-linking within the rubber matrix. The purpose of this research is to investigate the effect of gamma radiation dose and sensitizers on the physical properties of irradiated natural rubber. Three sensitizers n-butyl acrylate (n-B A), tetrachloroethylene (C 2 Cl 4 ) and trichloromethane (CHCl 3 ) were mixed with natural rubber latex before irradiation with gamma ray dose varied from 14 to 22 kGy. Results showed that the mixture of three sensitizers with specific ratios effectively induced the cross-linking of natural rubber latex. The cross-linking ratio and improved physical properties increased with increasing gamma dose. Therefore, the mixture ratios of n-B A, C 2 Cl 4 and CHCl 3 have shown to be a critical parameter in the vulcanization of natural rubber latex by gamma radiation

  10. Microwave pre-heating of natural rubber using a rectangular wave guide (MODE: TE10

    Directory of Open Access Journals (Sweden)

    Doo-ngam, N.

    2007-11-01

    Full Text Available This paper presents an application of microwave radiation for pre-heating of natural rubbercompounding with various sulphur contents. The natural rubber-compounding was pre-heated by microwave radiation using a rectangular wave guide system (MODE: TE10 operating at frequency of 2.45 GHz in which the power can vary from 0 to 1500 W. In the present work, the influence of power input, sample thickness, and sulphur content were examined after applying microwave radiation to the rubber samples. Results are discussed regarding the thermal properties, 3-D network, dielectric properties and chemical structures. From the result, firstly, it was found that microwave radiation can be applied to pre-heating natural rubber-compounding before the vulcanization process. Secondly, microwave radiation was very useful for pre-heating natural rubber-compounding that has a thickness greater than 5mm. Thirdly, crosslinking in natural rubber-compounding may occurs after pre-heating by microwave radiation though Fourier Transform Infrared Spectroscopy(FTIR. Finally, there a little effect of sulphur content on temperature profiles after applying microwave radiation to the natural rubber-compounding. Moreover, natural rubber-compounding without carbon black showed a lower heat absorption compared with natural rubbercompounding filled carbon black. This is due to the difference in dielectric loss factor. This preliminary result will be useful information in terms of microwave radiation for pre-heating natural rubber-compounding and rubber processing in industry.

  11. Analysis of Gel Permeation Chromatography From Irradiation Copolymer Grafting of Methylmethacrylate on to Natural Rubber

    International Nuclear Information System (INIS)

    Hendrana, Sunit; Purwanto, Indratmoko Hari; Karyaningsih, Ipit; Utama, MargaHerwinarni

    2004-01-01

    Grafting of methyl methacrylate (MMA) onto natural rubber was carried out by γ-irradiation using 60 Co source at dose rate 1 KGy/h and total dose of 5 KGy. Gel permeation chromatography (GPC) was used to analyse the grafting. The GPC's chromatogram, molecular weight and molecular weight distribution data indicate that grafting of MMA onto natural rubber and homo polymerization of MMA are the reaction mostly occurs. Meanwhile, the presence of natural rubber radical with a chain end natural rubber radical affect the PMMA homopolymer occurred

  12. Additive free thermoplastic vulcanizates based on natural rubber

    Energy Technology Data Exchange (ETDEWEB)

    Mondal, Manas, E-mail: mondal@ipfdd.de [Leibniz-Institut für Polymerforschung Dresden e.V., Institut für Polymerwerkstoffe, Hohe Straße 6, 01069 Dresden (Germany); Technische Universität Dresden, Institut für Werkstoffwissenschaft, 01069 Dresden (Germany); Gohs, Uwe, E-mail: gohs@ipfdd.de [Leibniz-Institut für Polymerforschung Dresden e.V., Institut für Polymerwerkstoffe, Hohe Straße 6, 01069 Dresden (Germany); Wagenknecht, Udo [Leibniz-Institut für Polymerforschung Dresden e.V., Institut für Polymerwerkstoffe, Hohe Straße 6, 01069 Dresden (Germany); Heinrich, Gert [Leibniz-Institut für Polymerforschung Dresden e.V., Institut für Polymerwerkstoffe, Hohe Straße 6, 01069 Dresden (Germany); Technische Universität Dresden, Institut für Werkstoffwissenschaft, 01069 Dresden (Germany)

    2013-12-16

    Electron induced reactive processing (EIReP) is an eco-friendly and sustainable reactive processing method based on the use of high energy electrons. It was used to cross-link the elastomeric domain phase during melt mixing in order to prepare natural rubber (NR) and polypropylene (PP) based thermoplastic vulcanizates (TPVs). The electron treatment with various values of absorbed dose showed a prominent effect on mechanical, rheological, and morphological characteristics of the PP/NR TPVs. SEM and TEM studies confirmed that these TPVs can exists across the co-continuous or discrete phase morphology. The maximum set of mechanical properties (tensile strength of 15 MPa and elongation at break of more than 500%) were obtained at an absorbed dose of 100 kGy for a 50/50 blend ratio of NR and PP without addition of any compatibilizer or chemicals. At higher values of absorbed dose the degradation of polypropylene showed a negative impact on the properties of the TPVs. Depending on the morphology and the evaluation of mechanical properties a structure–property co-relationship is drawn on the basis of common phenomenological understanding of the TPVs. - Highlights: • Dynamic vulcanization of 50:50 PP/NR blend by high energy electron beam. • PP/NR TPVs show rubber like behavior with melt processability. • High tensile strength of 15 MPa and large extensibility beyond 500%. • Complete phase inversed morphology from NR to PP matrix. • Vulcanized natural rubber particle size of 1–3 μm.

  13. Ultrasonic absorption and dielectric properties of natural rubber-furnace black mixtures: γ-irradiation effects

    International Nuclear Information System (INIS)

    Aziz, A.W.; Abd-El-Malak, N.A.; Abd El-Nour, K.N.

    1989-01-01

    The change in attenuation of longitudinal ultrasonic waves has been measured as a function of frequency and temperature for natural rubber samples loaded with semi-reinforcing oil furnace black (SRF) in increasing quantities and vulcanized with either mercaptobenzo-thiazol (MBT) or N-oxidethylene benzothiazol sulphenamide (OBTS) after being subjected to natural ageing for 8 years. One relaxation process was noticed in the range of frequency where the activation energy was calculated. Also, the dielectric constant ε ' and dielectric loss ε '' have been investigated for those samples in the frequency range from 10 2 to 10 5 Hz at room temperature (≅ 25 0 C). The results are compared with those previously obtained. The effect of 50 MR γ-irradiation on the dielectric properties of those samples was also studied and the results are interpreted. (Author)

  14. Ultraviolet curing of acrylated liquid natural rubber for surface coating application

    Directory of Open Access Journals (Sweden)

    Kannikar Kwanming

    2009-01-01

    Full Text Available Ultraviolet curable acrylated liquid natural rubber was prepared by grafting of photosensitive molecule onto liquid natural rubber for surface coating application. The liquid natural rubber (LNR was firstly obtained by degradation of natural rubber latex with hydrogen peroxide and cobalt acetylacetonate at 65oC for 72 hrs. The preparation of acrylated natural rubber was carried out by the reaction of acrylic acid and epoxidized liquid natural rubber (ELNR prior obtained from LNR with formic acid and hydrogen peroxide in the ratio of 2:1 by weight in toluene at 80oC for 6, 9, 12, 18, and 24 hrs. It was found that the percentage of acrylate grafted onto liquid natural rubber depended on the reaction time. Surface coating was performed by using acrylated liquid natural rubber and 1,6-hexanediol diacrylate (HDDA or tripropylene glycol diacrylate (TPGDA as a crosslinker and Irgarcure 184 or Irgarcure 651 as a photoinitiator under UV exposure for 30, 60, and 90 seconds. The hardness test of cured products was investigated using the Pencil hardness test at pencil level of 2B to 6H. It was found that the highest hardness of surface coating was at pencil level of 4H for the product using TPGDA and Irgacure 651 in the ratio of 80:10 parts per hundred of rubber (phr. The cured products were able to resist to 2% H2SO4 and distilled water for more than 24 hrs.

  15. Effects of different crumb rubber sizes on the flowability and compressive strength of hybrid fibre reinforced ECC

    Science.gov (United States)

    Khed, Veerendrakumar C.; Mohammed, Bashar S.; Fadhil Nuruddin, Muhd

    2018-04-01

    The different sizes of crumb rubber have been used to investigate the effects on flowability and the compressive strength of the hybrid fibre reinforced engineered cementitious composite. Two sizes of crumb rubber 30 mesh and 1 to 3mm were used in partial replacement with the fine aggregate up to 60%. The experimental study was carried out through mathematical and statistical analysis by response surface methodology (RSM) using the Design Expert software. The response models have been developed and the results were validated by analysis of variance (ANOVA). It was found that finer sized crumb rubber inclusion had produced better workability and higher compressive strength when compared to the larger size and it was concluded that crumb rubber has negative effect on compressive strength and positive effect on workability. The optimization results are found to an approximately good agreement with the experimental results.

  16. Temperature dependence of the elastocaloric effect in natural rubber

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Zhongjian, E-mail: zhongjian.xie521@gmail.com; Sebald, Gael; Guyomar, Daniel

    2017-07-12

    The temperature dependence of the elastocaloric (eC) effect in natural rubber (NR) has been studied. This material exhibits a large eC effect over a broad temperature range from 0 °C to 49 °C. The maximum adiabatic temperature change (ΔT) occurred at 10 °C and the behavior could be predicted by the temperature dependence of the strain-induced crystallization (SIC) and the temperature-induced crystallization (TIC). The eC performance of NR was then compared with that of shape memory alloys (SMAs). This study contributes to the SIC research of NR and also broadens the application of elastomers. - Highlights: • A large elastocaloric effect over a broad temperature range was found in natural rubber (NR). • The caloric performance of NR was compared with that of shape memory alloys. • The temperature dependence of the elastocaloric effect in NR can be prediced by the theory of strain-induced crystallization.

  17. Silylation of cellulose nanocrystals and their reinforcement of commercial silicone rubber

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Hou-Yong, E-mail: phdyu@zstu.edu.cn; Chen, Rui; Chen, Guo-Yin [Zhejiang Sci-Tech University, The Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education, College of Materials and Textile (China); Liu, Lin; Yang, Xiao-Gang; Yao, Ju-Ming, E-mail: yaoj@zstu.edu.cn [Zhejiang Sci-Tech University, National Engineering Lab for Textile Fiber Materials & Processing Technology (China)

    2015-09-15

    Poor interfacial compatibility between unmodified cellulose nanocrystals (CNCs) and rubber restricts the property enhancement of matrix materials. In this study, according to structural similarity, the silylated CNC (SCNC) with diameter of 5–30 nm were prepared and incorporated into commercial silicone rubber (SR) via two-roll mill-compounding and vulcanization processes. As expected, at the same loading levels, SCNC had stronger reinforcing effect on the SR matrix than CNC. Compared to neat SR, with only 0.3 wt% (0.3 phr) SCNC1 incorporated, the tensile strength, Young’s modulus, storage tensile modulus, and maximum decomposition temperature (T{sub max}) of the nanocomposite were improved by 72, 125, 66 %, and 110.8 °C, respectively. Meanwhile the nanocomposites showed an obvious decrease in water vapor permeability (67 %). These enhancements were attributed to good dispersion of SCNC within SR matrix, improved interfacial interaction, and high crosslinking density.

  18. The effect of gamma radiation on the ageing of sulfur cured nr/csm and nbr/csm rubber blends reinforced by carbon black

    Directory of Open Access Journals (Sweden)

    Gordana Marković

    2009-10-01

    Full Text Available In this work the effect of the γ-radiation dose on ageing of carbon black reinforced elastomeric materials was studied. The compounds based on natural rubber/chlorosulfonated rubber blend (NR/CSM and butadiene acrylonitrile rubber/chlorosulfonated rubber blend (NBR/CSM (50:50, w/w with different loadings (0, 20, 40, 50, 60, 80 and 100 phr of the filler with the average particle size of 40 nm were cured by sulfur. The obtained elastomeric composites were subjected to radiation doses (100, 200, 300 and 400 kGy in the presence of oxygen. The changes of material mechanical properties were estimated after radiation accelerated ageing. By using Fourier transform infrared measurements (ATR-FTIR it was assessed that after exposure to doses of 100 kGy alcohols, ethers, lactones, anhydrides, esters and carboxylic acids are formed in materials. The formation of shorter polyene sequences and aromatic rings in aged samples are assumed on the basis of the obtained spectra.

  19. Natural fiber-reinforced polymer composites

    International Nuclear Information System (INIS)

    Taj, S.; Khan, S.; Munawar, M.A.

    2007-01-01

    Natural fibers have been used to reinforce materials for over 3,000 years. More recently they have been employed in combination with plastics. Many types of natural fi fibers have been investigated for use in plastics including Flax, hemp, jute, straw, wood fiber, rice husks, wheat, barley, oats, rye, cane (sugar and bamboo), grass reeds, kenaf, ramie, oil palm empty fruit bunch, sisal, coir, water hyacinth, pennywort, kapok, paper-mulberry, raphia, banana fiber, pineapple leaf fiber and papyrus. Natural fibers have the advantage that they are renewable resources and have marketing appeal. The Asian markets have been using natural fibers for many years e.g., jute is a common reinforcement in India. Natural fibers are increasingly used in automotive and packaging materials. Pakistan is an agricultural country and it is the main stay of Pakistan's economy. Thousands of tons of different crops are produced but most of their wastes do not have any useful utilization. Agricultural wastes include wheat husk, rice husk, and their straw, hemp fiber and shells of various dry fruits. These agricultural wastes can be used to prepare fiber reinforced polymer composites for commercial use. This report examines the different types of fibers available and the current status of research. Many references to the latest work on properties, processing and application have been cited in this review. (author)

  20. Swelling behaviour of isora/natural rubber composites in oils used

    Indian Academy of Sciences (India)

    Natural rubber/isora fibre composites were cured at various temperatures. The solvent swelling characteristics of natural rubber composites containing both untreated and alkali treated fibres were investigated in aromatic and aliphatic solvents like toluene, and -hexane. The diffusion experiments were conducted by the ...

  1. Design of Self-Healing Supramolecular Rubbers by Introducing Ionic Cross-Links into Natural Rubber via a Controlled Vulcanization.

    Science.gov (United States)

    Xu, Chuanhui; Cao, Liming; Lin, Baofeng; Liang, Xingquan; Chen, Yukun

    2016-07-13

    Introducing ionic associations is one of the most effective approaches to realize a self-healing behavior for rubbers. However, most of commercial rubbers are nonpolar rubbers without now available functional groups to be converted into ionic groups. In this paper, our strategy was based on a controlled peroxide-induced vulcanization to generate massive ionic cross-links via polymerization of zinc dimethacrylate (ZDMA) in natural rubber (NR) and exploited it as a potential self-healable material. We controlled vulcanization process to retard the formation of covalent cross-link network, and successfully generated a reversible supramolecular network mainly constructed by ionic cross-links. Without the restriction of covalent cross-linkings, the NR chains in ionic supramolecular network had good flexibility and mobility. The nature that the ionic cross-links was easily reconstructed and rearranged facilitating the self-healing behavior, thereby enabling a fully cut sample to rejoin and retain to its original properties after a suitable self-healing process at ambient temperature. This study thus demonstrates a feasible approach to impart an ionic association induced self-healing function to commercial rubbers without ionic functional groups.

  2. Preparation of Multi-walled Carbon Nano tubes/ Natural Rubber Composite by Wet Mixing Method

    International Nuclear Information System (INIS)

    Azira Abdul Aziz; Azira Abdul Aziz; Che Su Mat Saad; Mohamad Rusop Mahmood

    2011-01-01

    Natural rubber/multi-walled carbon nano tubes (Nr/MWCNTs) nanocomposite is formed by incorporating nano tubes in a polymer solution and subsequently evaporating the solvent. Using this technique, nano tubes will be dispersed homogeneously in the NR matrix in an attempt to increase the mechanical properties of these nano composites. Mechanical test results show an increase in the tensile strength for up to 19 times in relation to pure NR. In addition to mechanical testing, the morphology of the MWNTs into NR was studied by Field Emission Scanning Electron Microscopy (FESEM) in order to understand the morphology of the resulting system. Slight shift noted from Raman analyses from each different wt. % of MWCNTs with the NR due to the stress transfer that indicates reinforcement of the nano tubes. (author)

  3. Nano-lignin filled natural rubber composites: Preparation and characterization

    Directory of Open Access Journals (Sweden)

    C. Jiang

    2013-05-01

    Full Text Available This paper presents a novel strategy to prepare nano-lignin and its composites with natural rubber. The nanolignin was ontained by fabricating colloidal lignin-Poly (diallyldimethylammonium chloride (PDADMAC complexes (LPCs via self-assembly technology. The characteristics of LPCs were investigated by zeta potential, dynamic light scattering (DLS, transmission electron microscopy (TEM, Fourier transform infrared spectroscopy (FTIR and ultraviolet – visible (UV-vis absorption measurements. The results indicated that PDADMAC intensively interacted with lignin by cation-π and π-π interactions, and lignin particles were stable in aqueous solution with an average particle size less than 100 nm. LPCs accelerated the vulcanization of NR/LPCs nanocomposites. Morphological studies and Dynamic mechanical analysis (DMA showed the homogeneous dispersion of LPCs in the NR matrix and the strong interfacial adhesion between them. The nanoscale dispersion of LPCs significantly enhanced the thermal stability and mechanical properties of NR/LPCs nanocomposites.

  4. Extractable protein content of radiation vulcanized natural rubber latex films

    International Nuclear Information System (INIS)

    Ma'zam Md Said; Wan Manshol Wan Zin

    1996-01-01

    The effects of processing conditions on extractable protein content of coagulant dipped radiation vulcanized natural rubber latex films have been investigated. Drying of wet-gel of radiation vulcanized latex films even at a relatively low temperature of 70 degree C resulted in increases of extractable protein content of the films. The extractable protein content is dependent upon both the temperature and time of drying of wet-gel deposit. Wet-gel leaching of film alone is not adequate to reduce the extractable protein content of films to low levels. Combination of wet-gel leaching, post-leaching, a dip in corn starch slurry, followed by drying at a low temperature of 70 degree C reduces the extractable protein content of films to very low levels

  5. The technologically-reinforced natural radioactivity

    International Nuclear Information System (INIS)

    2005-01-01

    Technologically-reinforced natural radioactivity comes from mining industries, geological resources and ores de-confinement, and from separation, purification, transformation and use of by-products or products. Partly based on a survey and questionnaires sent to industrial organisations, this report proposes a large and detailed overview of this kind of radioactivity for different sectors or specific activities: the French phosphate sector, the international rare Earth and heavy ores sector, the French monazite sector, the ilmenite sector, the French and international zirconium sector, the non-ferrous metal sector, the international and French drinkable, mineral and spring water sector, the international wastewater sector, the French drilling sector, the international and French geothermal sector, the international and French gas and oil sector, the international and French coal sector, the international and French biomass sector, the international and French paper-making industry, and the management of wastes with technologically-reinforced natural radioactivity in France

  6. An overview of the potentials of natural rubber ( Hevea brasiliensis ...

    African Journals Online (AJOL)

    Tapping rubber trees for valuable proteins will be more profitable compared to other options. The technologies have been developed and only needs to be adapted to our local conditions. It is hoped that this paper will be instructive to rubber farmers, policy makers, executors of policies or citizens wishing to join the Nigerian ...

  7. Ciprofloxacin release using natural rubber latex membranes as carrier.

    Science.gov (United States)

    Dias Murbach, Heitor; Jaques Ogawa, Guilherme; Azevedo Borges, Felipe; Romeiro Miranda, Matheus Carlos; Lopes, Rute; Roberto de Barros, Natan; Guedes Mazalli, Alexandre Vinicius; Gonçalves da Silva, Rosângela; Ferreira Cinman, José Luiz; de Camargo Drago, Bruno; Donizetti Herculano, Rondinelli

    2014-01-01

    Natural rubber latex (NRL) from Hevea brasiliensis is easily manipulated, low cost, is of can stimulate natural angiogenesis and cellular adhesion, is a biocompatible, material and presents high mechanical resistance. Ciprofloxacin (CIP) is a synthetic antibiotic (fluoroquinolone) used in the treatment of infection at external fixation screws sites and remote infections, and this use is increasingly frequent in medical practice. The aim of this study was to develop a novel sustained delivery system for CIP based on NRL membranes and to study its delivery system behavior. CIP was found to be adsorbed on the NRL membrane, according to results of energy dispersive X-ray spectroscopy. Results show that the membrane can release CIP for up to 59.08% in 312 hours and the mechanism is due to super case II (non-Fickian). The kinetics of the drug release could be fitted with double exponential function X-ray diffraction and Fourier transform infrared (FTIR) spectroscopy shows some interaction by hydrogen bound, which influences its mechanical behavior.

  8. Preparation of irradiated natural rubber latex-styrene copolymer for electrical gloves

    International Nuclear Information System (INIS)

    Made Sumarti Kardha

    2010-01-01

    Research on irradiated natural rubber latex-styrene copolymer to prepare electrical glove have been done. Vulcanization of natural rubber latex (NRL) was done by mixing 2 phr (per hundred of rubber) of normal butyl acrylate (n-BA) emulsion then irradiated with ã-ray "6"0Co at the dose of 30 kGy producing irradiated natural rubber latex (INRL). Natural rubber latex-styrene copolymers (SC) were prepared by mixing NRL and styrene monomer at styrene concentrations of 50 phr, 75 phr, 100 phr, 500 phr and irradiated at the doses of 15 kGy, 30 kGy and 45 kGy, then characterized their latex and film properties to obtain optimum SC of SC50. This optimum SC, SC50 then mixed with IRNL at the weight ratio of 0/100, 30/70, 50/50, 70/30 and 100/0, to produce irradiated natural rubber latex-styrene copolymer. The properties of copolymer rubber films made by dipping process i.e., % conversion, total solid content, latex viscosity, tensile strength, modulus 300 %, elongation at break, electrical resistance and dielectric constant were then characterized. Characterization result showed that (INRL-SC50) with 50/50 ratio irradiated at the dose of 30 kGy, have % conversion of 80.93 %, electrical resistivity of 1.73 x 10"1"4 Ohm cm and dielectric constant of 2.76 which fulfill the requirement as material for electrical gloves. (author)

  9. Polymer Electrolyte Prepared from Highly Deproteinized Natural Rubber Having Epoxy Group

    Science.gov (United States)

    Klinklai, W.; Kawahara, S.; Isono, Y.; Mizumo, T.; Yoshizawa, M.; Ohno, H.

    Deproteinized natural rubber having epoxy group (EDPNR) was applied to transport Li+ as a solid polymer electrolyte. The deproteinized natural rubber, incubated with proteolytic enzyme and surfactant, was subjected to epoxidation followed by oxidative depolymerization in latex stage. The resulting rubber was proved to be a liquid deproteinized natural rubber (LEDPNR) having polar epoxy groups, low Tg, low Mn and well-defined terminal units. Ionic conductivity of LEDPNR mixed with alkali metal salts was investigated through impedance analysis to clarify an effect of proteins present in the rubber. The ionic conductivity of the resulting LEDPNR depended on the kind of salts, their concentrations and temperature. The ionic conductivity of LEDPNR/lithium bis(trifluoromethan sulfonyl)imide (LiTFSI) was higher than that of LEDPNR/ lithium perchlorate (LiClO4). The difference in the ionic conductivity was attributed to the solubility of the salts as results of both high-resolution solid-state 13C-NMR spectroscopy and measurements of spin-lattice relaxation time. The conductivity of LEDPNR/LiTFSI was also dependent upon concentrations of LiTFSI and it reached the highest value at 20 wt%, which was different from the monotonic increase in the Li+ conductivity of liquid epoxidized natural rubber prepared from untreated natural rubber.

  10. Analysis of Physical Properties and Mineralogical of Pyrolysis Tires Rubber Ash Compared Natural Sand in Concrete material

    Science.gov (United States)

    Syamir Senin, Mohamad; Shahidan, Shahiron; Syazani Leman, Alif; Izzati Raihan Ramzi Hannan, Nurul

    2016-11-01

    Waste tires pose significant health and environmental concerns if not recycled or discarded properly. At the same time, natural sand is becoming scarcer and costlier due to its non-availability. Waste tires as fine aggregate can be an economical and sustainable alternative to the natural sand. Recent years, the interest on recycling waste tires into civil engineering applications by the researchers has increased. In this research, the chemical and physical properties of the tires rubber ash and the natural sand have been analysed. The densities of the rubber ash are lower than the natural sand. Rubber ash had finer particle size compared to the natural sand. Almost all chemical in the natural sand had in rubber ash with the additional sulphur trioxide and zinc oxide in the rubber ash, made the rubber ash better than natural sand. Rubber ash seems to be a suitable material to use in concrete as sand replacement.

  11. In-plane mechanics of soft architectured fibre-reinforced silicone rubber membranes.

    Science.gov (United States)

    Bailly, L; Toungara, M; Orgéas, L; Bertrand, E; Deplano, V; Geindreau, C

    2014-12-01

    Silicone rubber membranes reinforced with architectured fibre networks were processed with a dedicated apparatus, allowing a control of the fibre content and orientation. The membranes were subjected to tensile loadings combined with continuous and discrete kinematical field measurements (DIC and particle tracking). These tests show that the mechanical behaviour of the membranes is hyperelastic at the first order. They highlight the influence of the fibre content and orientation on both the membrane in-plane deformation and stress levels. They also prove that for the considered fibrous architectures and mechanical loadings, the motion and deformation of fibres is an affine function of the macroscale transformation. These trends are fairly well described by the micromechanical model proposed recently in Bailly et al. (JMBBM, 2012). This result proves that these materials are very good candidates for new biomimetic membranes, e.g. to improve aortic analogues used for in vitro experiments, or existing textiles used for vascular (endo)prostheses. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Sound Absorption Properties Of Single-Hole Hollow Polyester Fiber Reinforced Hydrogenated Carboxyl Nitrile Rubber Composites

    Directory of Open Access Journals (Sweden)

    Jie Hong

    2017-09-01

    Full Text Available A series of single-hole hollow polyester fiber (SHHPF reinforced hydrogenated carboxyl nitrile rubber (HXNBR composites were fabricated. In this study, the sound absorption property of the HXNBR/SHHPF composite was tested in an impedance tube, the composite morphology was characterized by scanning electron microscope (SEM, and the tensile mechanical property was measured by strength tester. The results demonstrated that a remarkable change in sound absorption can be observed by increasing the SHHPF content from 0% to 40%. In the composite with 40% SHHPF in 1 mm thickness, the sound absorption coefficient reached 0.671 at 2,500 Hz; the effective bandwidth was 1,800-2,500 Hz for sound absorption coefficient larger than 0.2. But the sound absorption property of the composite deteriorated when the SHHPF content increased to 50% in 1 mm thickness. While with 20% SHHPF proportion, the sound absorption property was improved by increasing the thickness of composites from 1 to 5 mm. Compared with the pure HXNBR of the same thickness, the tensile mechanical property of the composite improved significantly by increasing the SHHPF proportion. As a lightweight composite with excellent sound absorption property, the HXNBR/SHHPF composite has potential practical application value in the fields of engineering.

  13. Synthesis, characterization and degradation behavior of admicelled polyacrylate-natural rubber

    International Nuclear Information System (INIS)

    Pongpilaipruet, Angkana; Magaraphan, Rathanawan

    2015-01-01

    In order to improve weatherability of the cured natural rubber, the novel introduction of good ozone resistant polymers such as polyacrylates (poly(methyl acrylate) (PMA) or poly(methyl methacrylate) (PMMA)) into natural rubber (NR) by admicellar polymerization was investigated in this work. The admicellar polymerization to synthesize polyacrylate layer over the surface of NR latex particles was performed with varying monomer type (PMA and PMMA) and content (50 and 100 mM). The admicelled PMMA showed higher molecular weight than PMA. Fourier transform infrared spectra of the admicellar synthesized natural rubbers exhibited characteristic peaks of those polyacrylates. Micrographs from transmission electron and field emission scanning electron microscopes (FE-SEM) revealed the coatings of PMA and PMMA over the rubber particles, suggesting a core-shell structure. Thermogravimetric analysis revealed that the admicelled rubbers not only showed an improvement in heat stability but also a single decomposition temperature. After vulcanization, FE-SEM results showed the cured admicelled rubbers had phase transformation from core-shell to phase separation (aggregate domains of polyacrylate-rich phase) with smooth interface. This agreed well to their one glass transition temperature (∼−48 °C) which indicated good miscibility between NR and each polyacrylate. The cracks generated after exposure to ozone found in the admicelled rubbers were smaller than those in NR, suggesting better ozone resistance was achieved. Increasing monomer concentration led to less cracks or much better ozone resistance. Furthermore, changes in mechanical properties after ozone exposure of the admicelled PMA-NR were less than those of the admicelled PMMA-NR (having the same shell content) and the NR, respectively. - Highlights: • We use admicellar technique to add polyacrylates to NR in form of core-shell rubber. • This core-shell structure was physically formed as seen by the phase

  14. Synthesis, characterization and degradation behavior of admicelled polyacrylate-natural rubber

    Energy Technology Data Exchange (ETDEWEB)

    Pongpilaipruet, Angkana; Magaraphan, Rathanawan, E-mail: rathanawan.k@chula.ac.th

    2015-06-15

    In order to improve weatherability of the cured natural rubber, the novel introduction of good ozone resistant polymers such as polyacrylates (poly(methyl acrylate) (PMA) or poly(methyl methacrylate) (PMMA)) into natural rubber (NR) by admicellar polymerization was investigated in this work. The admicellar polymerization to synthesize polyacrylate layer over the surface of NR latex particles was performed with varying monomer type (PMA and PMMA) and content (50 and 100 mM). The admicelled PMMA showed higher molecular weight than PMA. Fourier transform infrared spectra of the admicellar synthesized natural rubbers exhibited characteristic peaks of those polyacrylates. Micrographs from transmission electron and field emission scanning electron microscopes (FE-SEM) revealed the coatings of PMA and PMMA over the rubber particles, suggesting a core-shell structure. Thermogravimetric analysis revealed that the admicelled rubbers not only showed an improvement in heat stability but also a single decomposition temperature. After vulcanization, FE-SEM results showed the cured admicelled rubbers had phase transformation from core-shell to phase separation (aggregate domains of polyacrylate-rich phase) with smooth interface. This agreed well to their one glass transition temperature (∼−48 °C) which indicated good miscibility between NR and each polyacrylate. The cracks generated after exposure to ozone found in the admicelled rubbers were smaller than those in NR, suggesting better ozone resistance was achieved. Increasing monomer concentration led to less cracks or much better ozone resistance. Furthermore, changes in mechanical properties after ozone exposure of the admicelled PMA-NR were less than those of the admicelled PMMA-NR (having the same shell content) and the NR, respectively. - Highlights: • We use admicellar technique to add polyacrylates to NR in form of core-shell rubber. • This core-shell structure was physically formed as seen by the phase

  15. Characterization of the natural rubber from new rubber tree clones of PB 300 series; Caracterizacao da borracha natural dos novos clones de seringueira da serie PB 300

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Maycon J.; Spinelli, Rafaela O.; Moreno, Rogerio M.B.; Mattoso, Luiz H.C.; Martins, Maria Alice, E-mail: maria-alice.martins@embrapa.br [Embrapa Instrumentacao/LNNA, Sao Carlos, SP (Brazil); Scaloppi Junior, Erivaldo J. [Instituto Agronomico (IAC), Votuporanga, SP (Brazil). Centro de Seringueira e Sistemas Agroflorestais; Goncalves, Paulo de S. [Instituto Agronomico (IAC), Campinas, SP (Brazil)

    2015-07-01

    The natural rubber (NR) is present in more than 2500 species of plants, being the Hevea brasiliensis the most commercially exploited. It is a raw material of great importance to the Brazilian economy, but the country faces a production's deficit, having to import about 60% of its consumption. In this work , the latex obtained from rubber tree of new clones of PB series 300 (PB 311, PB 312, PB 314 , PB 326, PB 346 and PB 350 ) and RRIM 600 (control) were characterized by dry rubber content (DRC), total solids content, distribution of particle size, Zeta potential, thermogravimetry, differential scanning calorimetry, infrared in the spectroscopy (FTIR), nuclear magnetic resonance (NMR) and technological properties. The DRC values ranged from 33% to 40%, and total solids of 38% to 44%. All of the clones showed average particle diameter between 180.0 to 192.1 nm, excluding clones PB 326 and PB 346 with 150.0 nm and 157.9 nm, respectively. The NMR spectra and FTIR showed that the structure of the natural rubber from all clones studied is cis -1,4- polyisoprene. Natural rubber from the new clones showed good thermal stability up to 285 °C and glass transition temperature of -64 °C. (author)

  16. Hydrogenation of liquid natural rubber via diimide reduction in hydrazine hydrate/hydrogen peroxide system

    International Nuclear Information System (INIS)

    Yusof, Muhammad Jefri Mohd; Jamaluddin, Naharullah; Abdullah, Ibrahim; Yusoff, Siti Fairus M.

    2015-01-01

    Liquid natural rubber (LNR) with molecular weight of lower than 10 5 and shorter polymeric chain than natural rubber was prepared. LNR was then hydrogenated via diimide reduction by oxidation of hydrazine hydrate with hydrogen peroxide. The unsaturated units of the rubber were converted into saturated hydrocarbon to strengthen the backbone of the polymer so it was able to resist thermal degradation. The results indicated that hydrogenation degree of the product (HLNR) could be extended to 91.2% conversion under appropriate conditions. The hydrogenated LNR (HLNR) was characterized using Fourier-Transform Infrared (FTIR) and Nuclear Magnetic Resonance (NMR) spectroscopy. The physical characteristics of HLNR were analyzed with Termogravimetric Analysis (TGA)

  17. Hydrogenation of liquid natural rubber via diimide reduction in hydrazine hydrate/hydrogen peroxide system

    Science.gov (United States)

    Yusof, Muhammad Jefri Mohd; Jamaluddin, Naharullah; Abdullah, Ibrahim; Yusoff, Siti Fairus M.

    2015-09-01

    Liquid natural rubber (LNR) with molecular weight of lower than 105 and shorter polymeric chain than natural rubber was prepared. LNR was then hydrogenated via diimide reduction by oxidation of hydrazine hydrate with hydrogen peroxide. The unsaturated units of the rubber were converted into saturated hydrocarbon to strengthen the backbone of the polymer so it was able to resist thermal degradation. The results indicated that hydrogenation degree of the product (HLNR) could be extended to 91.2% conversion under appropriate conditions. The hydrogenated LNR (HLNR) was characterized using Fourier-Transform Infrared (FTIR) and Nuclear Magnetic Resonance (NMR) spectroscopy. The physical characteristics of HLNR were analyzed with Termogravimetric Analysis (TGA).

  18. Hydrogenation of liquid natural rubber via diimide reduction in hydrazine hydrate/hydrogen peroxide system

    Energy Technology Data Exchange (ETDEWEB)

    Yusof, Muhammad Jefri Mohd; Jamaluddin, Naharullah; Abdullah, Ibrahim; Yusoff, Siti Fairus M. [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2015-09-25

    Liquid natural rubber (LNR) with molecular weight of lower than 10{sup 5} and shorter polymeric chain than natural rubber was prepared. LNR was then hydrogenated via diimide reduction by oxidation of hydrazine hydrate with hydrogen peroxide. The unsaturated units of the rubber were converted into saturated hydrocarbon to strengthen the backbone of the polymer so it was able to resist thermal degradation. The results indicated that hydrogenation degree of the product (HLNR) could be extended to 91.2% conversion under appropriate conditions. The hydrogenated LNR (HLNR) was characterized using Fourier-Transform Infrared (FTIR) and Nuclear Magnetic Resonance (NMR) spectroscopy. The physical characteristics of HLNR were analyzed with Termogravimetric Analysis (TGA)

  19. Swelling behaviour of isora/natural rubber composites in oils used in ...

    Indian Academy of Sciences (India)

    Unknown

    Department of Polymer Science and Rubber Technology, Cochin University of Science and Technology,. Kochi 682 022 ... natural resources have prompted the composite industry to .... provided information on the interface strength, degree of.

  20. Microstructure, molecular weight and thermal behavior of natural rubber (NR) from mangabeira (Hancornia speciosa)

    International Nuclear Information System (INIS)

    Santos, Expedito Flavio dos; Feitosa, Judith P.A.; Ricardo, Nagila M.P.S.

    2001-01-01

    The natural rubber (NR) from Hancornia speciosa contains characteristics that turns it a good alternative in elastomers supply. The NMR and IR spectra showed that the rubber of mangabeira is composed fundamentally by poly(1,4-cis-isoprene). The rubber molecular weight obtained by GPC and viscometry was 2,0x10 6 and 1,3x10 6 g/mol, respectively, in good agreement with the values determined for seringueira and manicoba NR. The glass transition temperature obtained by DSC (Tg = - 65 deg C) showed the mangabeira rubber is ideal to be utilized in regions of cold climate without compromising its mechanical properties. The rubber has also good thermal stability up to 213 deg C, as indicated by TG curves. This results indicated that the mangabeira NR can be effectively used in vulcanized articles or to be added to asphalt. (author)

  1. Study on preparation of new antioxidants for radiation vulcanized natural rubber latex product. Antioxidant from keratin

    International Nuclear Information System (INIS)

    Nguyen Quoc Hien; Nguyen Van Toan; Vo Tan Thien; Le Hai

    2000-01-01

    The thermo-oxidative aging resistance of radiation vulcanization of natural rubber latex (RVNRL) products should be adequately by using suitable antioxidants or new kind of effective antioxidant. This work presents the results of preparation of natural antioxidant from hair keratin. Characteristics and effectiveness of resultant antioxidant are also presented. The results obtained indicates that antioxidant made from hair keratin is safe and effective for rubber products from RVNRL. (author)

  2. Effect of maleated natural rubber on tensile strength and compatibility of natural rubber/coconut coir composite

    Science.gov (United States)

    Ujianto, O.; Noviyanti, R.; Wijaya, R.; Ramadhoni, B.

    2017-07-01

    Natural rubber (NR)/coconut coir (CF) composites were fabricated using co-rotating twin screw extruder with maleated NR (MNR) used as compatibilizer. The MNR was produced at three level of maleic anhydride (MA), and analyzed qualitative and quantitatively using FTIR and titration technique. Analysis on MNR using FTIR and titration methods showed that MA was grafted on NR chain at different percentage (0.76, 2.23, 4.79%) depended on MA concentration. Tensile strength data showed the best tensile strength was produced at 7 phr of MNR with 1 phr of MA level in MNR resulting 16.4 MPa. The improvement of compatibilized samples were more than 300% compare to uncompatibilized composite attributed to better interfacial bonding. The improvement on tensile strength was significantly influenced by MNR level and amount of MA added to produce MNR, as well as their interaction. The optimum conditions for producing NR-CF composite were predicted at 6.5 phr of MNR level with 1 phr of MA concentration added in MNR production, regardless screw rotation settings. Results from verification experiments confirm that developed model was capable of describing phenomena during composite preparation. Morphology analysis using scanning electron microscopy shows smooth covered fiber in compatibilized samples than that of without MNR. The morphology also showed less voids on compatibilized samples attributed to better interfacial bonding leading to tensile strength improvement.

  3. Dielectric properties of various polymers (PVC, EVA, HDPE, and PP) reinforced with ground tire rubber (GTR)

    OpenAIRE

    Mujal Rosas, Ramón María; Marín Genescá, Marcos; Ballart Prunell, Jordi

    2015-01-01

    Mass production of tires as well as its difficult storage or elimination is a real environmental problem. Various methods for recycling tires are currently used, such as mechanical crushing, which puts vulcanized rubber, steel, and fibers apart. The rubber may be used in several industrial applications such as flooring, insulations, and footwear. The present paper focuses on finding a new application for old used tires [ground tire rubber (GTR)]. To this end, tires dust has been mixed with va...

  4. Evaluation of Permanent Deformation of Unmodified and Rubber-Reinforced SMA Asphalt Mixtures Using Dynamic Creep Test

    Directory of Open Access Journals (Sweden)

    Herda Yati Katman

    2015-01-01

    Full Text Available This paper presents the evaluation of permanent deformation of rubber-reinforced SMA asphalt mixtures by using dynamic creep test. The effect of trans-polyoctenamer as a cross-linking agent in permanent deformation of rubberized mixtures was also evaluated. Dynamic creep test was conducted at different stress levels (200 kPa, 400 kPa and temperatures (40°C, 50°C. Permanent deformation parameters such as dynamic creep curve, ultimate strain, and creep strain slope (CSS were used to analyse the results. Finally, the creep behaviour of the specimens was estimated by the Zhou three-stage creep model. The results show that crumb rubber and trans-polyoctenamer significantly affected the parameters especially at high stress and temperatures. Consistent findings were observed for all permanent deformation parameters. Moreover, based on Zhou model, it was concluded that resistance to permanent deformation was improved by application of crumb rubber and trans-polyoctenamer.

  5. Hardness and swelling behaviour of epoxidized natural rubber/recycled acrylonitrile-butadiene rubber (ENR 50/NBRr) blends

    Science.gov (United States)

    Ahmad, Hazwani Syaza; Ismail, Hanafi; Rashid, Azura A.

    2017-07-01

    This recent work is to investigate the hardness and swelling behaviour of epoxidized natural rubber/recycled acrylonitrile-butadiene rubber (ENR 50/NBRr) blends. ENR 50/NBRr blends were prepared by two-roll mills with five different loading of NBRr from 5 to 35 phr. Results indicated that the hardness of ENR 50/NBRr blends increased as recycled NBR increased due to the improvement in crosslink density of the blends. Increasing NBRr content gives ENR 50/NBRr blends better resistance towards swelling. Higher degree of crosslinking will increase the swelling resistance and reduce the penetration of toluene into the blends. The presence of polar group in ENR 50 and NBRr give better hardness properties and swelling behaviour of the ENR 50/NBRr blends compared to the NR/NBRr blends.

  6. Effect of silica particles modified by in-situ and ex-situ methods on the reinforcement of silicone rubber

    International Nuclear Information System (INIS)

    Song, Yingze; Yu, Jinhong; Dai, Dan; Song, Lixian; Jiang, Nan

    2014-01-01

    Highlights: • In-situ and ex-situ methods were applied to modify silica particles. • In-situ method was more beneficial to preparing silica particles with high BET surface area. • Silicone rubber filled with in-situ modified silica exhibits excellent mechanical and thermal properties. - Abstract: In-situ and ex-situ methods were applied to modify silica particles in order to investigate their effects on the reinforcement of silicone rubber. Surface area and pore analyzer, laser particle size analyzer, Fourier-transform infrared spectroscopy (FTIR), contact-angle instrument, and transmission electron microscope (TEM) were utilized to investigate the structure and properties of the modified silica particles. Dynamic mechanical thermal analyzer (DMTA) was employed to characterize the vulcanizing behavior and mechanical properties of the composites. Thermogravimetric analysis (TGA) was performed to test the thermal stability of the composites. FTIR and contact angle analysis indicated that silica particles were successfully modified by these two methods. The BET surface area and TEM results reflected that in-situ modification was more beneficial to preparing silica particles with irregular shape and higher BET surface area in comparison with ex-situ modification. The DMTA and TGA data revealed that compared with ex-situ modification, the in-situ modification produced positive influence on the reinforcement of silicone rubber

  7. Thermal analysis and microstructure of hexaperrite based magnet composite with natural rubber matrix

    International Nuclear Information System (INIS)

    Sudirman; Ridwan; Jamilah; Trijono, Waluyo

    2000-01-01

    Thermal and microstructure analyse of hexa ferrite based on composite magnets with natural rubber matrix have been done to investigate their performance. Such magnets play an important role in the toy and house-hold industries because of their suitable magnetic properties, low cost, lightness and flexibility. The composite magnets were synthesized by blending the ferrite powder and natural rubber at composition 30%-70% rubber volume. The microstructure and thermal behaviour of the composite were examined by using SEM and OTA/TGA. The result show that the natural rubber swelling is optimally at 181,17 o C, which is the recommended top condition for blending. The performance magnet composite is limited by the change of natural rubber properties which decompose at temperature around 400 o C. In the decomposition process, the natural rubber molecule trapped in a composite system based on BaM is more difficult are more compared to the composite system based on SrM because the BaM system particle microstructure and its distribution more homogeneous

  8. Development of SBR-Nano clay Composites with Epoxidized Natural Rubber as Compatibilizer

    International Nuclear Information System (INIS)

    Rajasekar, R.; Das, Ch.K.; Gert Heinrich, G.; Das, A.

    2009-01-01

    The significant factor that determines the improvement of properties in rubber by the incorporation of nano clay is its distribution in the rubber matrix. The simple mixing of nonpolar rubber and organically modified nano clay will not contribute for the good dispersion of nano filler in the rubbery matrix. Hence a polar rubber like epoxidized natural rubber (ENR) can be used as a compatibilizer in order to obtain a better dispersion of the nano clay in the matrix polymer. Epoxidized natural rubber and organically modified nano clay composites (EC) were prepared by solution mixing. The nano clay employed in this study is Cloisite 20A. The obtained nano composites were incorporated in styrene butadiene-rubber (SBR) compounds with sulphur as a curing agent. The morphology observed through X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HR-TEM) shows that the nano clay is highly intercalated in ENR, and further incorporation of EC in SBR matrix leads to partial exfoliation of the nano clay. Dynamic mechanical thermal analysis showed an increase in storage modulus and lesser damping characteristics for the compounds containing EC loading in SBR matrix. In addition, these compounds showed improvement in the mechanical properties.

  9. ENHANCEMENT OF RESISTANCE TO OXIDATIVE DEGRADATION OF NATURAL RUBBER THROUGH LATEX DEGRADATION

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    A fully characterised natural rubber latex was subjected to mechanical degradation by stirring at intervals. The resistance to oxidative degradation of the different samples were studied by measuring the Plasticity retention indices (PRI).The results show that there is an enhancement of the PRI from 57% for the undegraded rubber to 79% for the one-hour degraded sample. Further degradation resulted in decrease of PRI as time of degradation increased. Therefore, the one-hour degraded sample is a special rubber with high oxidation resistance which is of great importance in engineering.

  10. Rubber materials from elastomers and nanocellulose powders: filler dispersion and mechanical reinforcement.

    Science.gov (United States)

    Fumagalli, Matthieu; Berriot, Julien; de Gaudemaris, Benoit; Veyland, Anne; Putaux, Jean-Luc; Molina-Boisseau, Sonia; Heux, Laurent

    2018-04-04

    Rubber materials with well-dispersed fillers and large mechanical reinforcement have been obtained by melt-processing a diene elastomer matrix and tailored nanocellulose powders having both a high specific surface area and a modified interface. Such filler powders with a specific surface area of 180 m2 g-1 and 100 m2 g-1 have been obtained by freeze-drying suspensions of short needle-like cellulose nanocrystals (CNCs) and entangled networks of microfibrillated cellulose (MFC) in tert-butanol/water, respectively. A quantitative and toposelective filler surface esterification was performed using a gas-phase protocol either with palmitoyl chloride (PCl) to obtain a hydrophobic but non-reactive nanocellulose interface, or with 3,3'-dithiopropionic acid chloride (DTACl) to introduce reactive groups that can covalently bind the nanocellulose interface to the dienic matrix in a subsequent vulcanization process. A set of filled materials was prepared varying the filler morphology, interface and volume fraction. Transmission electron microscopy images of ultrathin cryo-sections showed that modified nanocellulose fillers presented a relatively homogeneous distribution up to a volume fraction of 20%. The materials also exhibited a significant modulus increase, while keeping an extensibility in the same range as that of the neat matrix. Strikingly, in the case of the reactive interface, a strong stress-stiffening behavior was evidenced from the upward curvature of the tensile curve, leading to a large increase of the ultimate stress (up to 7 times that of the neat matrix). Taken together, these properties, which have never been previously reported for nanocellulose-filled elastomers, match well the mechanical characteristics of industrial carbon black or silica-loaded elastomers.

  11. Unraveling the mystery of natural rubber biosynthesis. Part II. Composition and growth of in vitro natural rubber using high-resolution size exclusion chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, Cheng Ching K. [Univ. of Akron, OH (United States); Barkakaty, Balaka [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Puskas, Judit E. [Univ. of Akron, OH (United States); Xie, Wenshuang [The Ohio State Univ., Wooster, OH (United States); Cornish, Katrina [The Ohio State Univ., Wooster, OH (United States); Peruch, Federic [Univ. of Bordeaux, Pessac Cedex (France); Deffieux, Alain [Univ. of Bordeaux, Pessac Cedex (France)

    2014-09-01

    The superior properties of natural rubber (cis-1,4-polyisoprene [NR]) are a function of its structure and composition, properties that still remain a mystery and that are irreplaceable by any synthetic rubber. NR from guayule (Parthenium argentatum) has been gaining special interest for its hypoallergenic properties while maintaining superior mechanical properties that are commonly associated with the Brazilian rubber tree (Hevea brasiliensis), the most common source of NR. Techniques exist to isolate washed rubber particles (WRPs) that contain enzymatically active rubber transferase, to study NR biosynthesis, and previous work on the in vitroNRgrowth in Hevea has demonstrated the presence of around 50wt%of a low molecular weight ([MW], Mn <10 000 g/mol) fraction. Structural and compositional analyses of this low MW fraction in Hevea are challenging due to the high protein content. Here, we discuss the analysis and composition of guayule latex and WRPs using high-resolution Size Exclusion Chromatography. We also discuss the composition of the soluble fraction of inactive guayule latex using matrix-assisted laser desorption ionization/time of flight mass spectrometry.

  12. Degradation of non-vulcanized natural rubber - renewable resource for fine chemicals used in polymer synthesis

    Directory of Open Access Journals (Sweden)

    Alexander Fainleib

    2013-01-01

    Full Text Available In the current scenario, there is growing interest in the products of degradation of rubber (natural and synthetic for specific applications in different industry sectors, whose benefits in replacing conventionally used products are mainly related to sustainability. Since the degradation products of rubber can be used in different areas, several research groups may have the interest aroused by these products, but are not familiar with the aspects related to the chemical behavior of rubber. This review aims to bring together the key information in the published literature on the degradation of natural rubber, emphasizing metatheses reactions, oxidative damage and splitting of the double bond, in order to serve as a reference source for researchers from different fields interested in obtaining such kind of products. The structures and properties as well as additional chemical transformations resulting in oligomers of isoprene, functionalised oligomers and polymers based on both are also described.

  13. Blends of natural rubber and polyurethane lattices studied by solid-state NMR

    International Nuclear Information System (INIS)

    Ricardo, Nagila M.P.S.; Franca, Francisco C.F. de; Price, Colin; Heatley, Frank

    2001-01-01

    Molecular mixing in films formed from a mixture of a polyurethane and natural rubber lattices has been studied using 1 H and 13 C solid-state NMR. The techniques employed include 1 H relaxation measurements, and 13 C cross-polarisation and direct excitation methods. The spectra of the blends were essentially a weighted superposition of the spectra of the individual components, indicating that the polyurethane and rubber remained phase-separated in large domains. (author)

  14. Effect of Ingredient Loading on Surface Migration Kinetics of Additives in Vulcanized Natural Rubber Compounds

    Directory of Open Access Journals (Sweden)

    Bryan B. Pajarito

    2014-12-01

    Full Text Available Surface migration kinetics of chemical additives in vulcanized natural rubber compounds were studied as function of ingredient loading. Rubber sheets were compounded according to a 212-8 fractional factorial design of experiment, where ingredients were treated as factors varied at two levels of loading. Amount of migrated additives in surface of rubber sheets was monitored through time at ambient conditions. The maximum amount and estimated rate of additive migration were determined from weight loss kinetic curves. Attenuated total reflection–Fourier transform infrared (ATR-FTIR spectroscopy and optical microscopy were used to characterize the chemical structure and surface morphology of sheet specimens during additive migration. ANOVA results showed that increased loading of reclaimed rubber, CaCO3, and paraffin wax signif icantly decreased the maximum amount of additive migration; by contrast, increased loading of used oil, asphalt, and mercaptobenzothiazole disulphide (MBTS increased the maximum amount. Increased loading of sulfur, diphenylguanidine (DPG, and paraffin wax significantly decreased the additive migration rate; increased loading of used oil, asphalt, and stearic acid elicited an opposite effect. Comparison of ATRFTIR spectra of migrated and cleaned rubber surfaces showed signif icant variation in intensity of specif ic absorbance bands that are also present in infrared spectra of migrating chemicals. Paraffin wax, used oil, stearic acid, MBTS, asphalt, and zinc stearate were identified to bloom and bleed in the rubber sheets. Optical micrographs of migrated rubber surfaces revealed formation of white precipitates due to blooming and of semi-transparent wet patches due to bleeding.

  15. Continuous Natural Fiber Reinforced Thermoplastic Composites by Fiber Surface Modification

    Directory of Open Access Journals (Sweden)

    Patcharat Wongsriraksa

    2013-01-01

    Full Text Available Continuous natural fiber reinforced thermoplastic materials are expected to replace inorganic fiber reinforced thermosetting materials. However, in the process of fabricating the composite, it is difficult to impregnate the thermoplastic resin into reinforcement fiber because of the high melt viscosity. Therefore, intermediate material, which allows high impregnation during molding, has been investigated for fabricating continuous fiber reinforced thermoplastic composite by aligning resin fiber alongside reinforcing fiber with braiding technique. This intermediate material has been called “microbraid yarn (MBY.” Moreover, it is well known that the interfacial properties between natural fiber and resin are low; therefore, surface treatment on continuous natural fiber was performed by using polyurethane (PU and flexible epoxy (FLEX to improve the interfacial properties. The effect of surface treatment on the mechanical properties of continuous natural fiber reinforced thermoplastic composites was examined. From these results, it was suggested that surface treatment by PU with low content could produce composites with better mechanical properties.

  16. Effect of Zeolite Treatment on the Blooming Behavior of Paraffin Wax in Natural Rubber Composites

    Directory of Open Access Journals (Sweden)

    Bryan B. Pajarito

    2016-06-01

    Full Text Available The blooming behavior of paraffin wax in natural rubber (NR composites was studied as function of zeolite treatment. Three types of zeolite treatment were treated as factors: acid activation using hydrochloric acid (HCl solution, ion exchange using tetradecyldimethyl amine (TDA chloride salt, and organic modification using glycerol monostearate (GMS. The zeolite was treated according to a 23 full factorial design of experiment. Attenuated total reflectance – Fourier transform infrared (ATR-FTIR spectroscopy was used to characterize the chemical structure of treated zeolite. Treated zeolite was applied as filler to NR composites deliberately compounded with high amount of paraff in wax. The amount of bloomed wax in surface of NR composite sheets was monitored with time at 50oC. Results show the bloom amount to be linear with the square root of time. NR composites reinforced with untreated, acid-activated, and ion-exchanged zeolite fillers indicate reduction in wax blooming as compared to unfilled NR. The bloom rate (slope and initial bloom (y-intercept were determined from the experimental plots. Analysis of variance (ANOVA shows the bloom rate to be signif icantly increased when zeolite fillers are treated with GMS. Meanwhile, initial bloom was significantly enhanced when zeolite fillers are treated with TDA chloride salt and GMS. The significant increase in bloom rate and initial bloom can be attributed to the softening of the NR matrix at high amounts of TDA chloride salt and GMS.

  17. Preparation of novel flame-retardant organoclay and its application to natural rubber composites

    Science.gov (United States)

    Zhang, Guangjian; Wang, Jincheng

    2018-04-01

    In this study, a novel type of flame-retardant montmorillonite (MMT) was prepared using a new approach to obtain highly branched polymer chains. First, MMT was modified using a small liquid crystal molecule comprising N,N,N tris(2-hydroxyethyl)sbnd N-dodecylammonium bromide and organic MMT (OMMT) was obtained. Next, three generations of dendrimer-modified organoclay comprising DOMMT-1, DOMMT-2, and DOMMT-3 were successfully prepared using OMMT and branching units of ethylenediamine and methyl acrylate. Their chemical structures were characterized and confirmed by different methods. The DOMMT organoclay was used in the preparation of natural rubber (NR) composites. The tensile strength and elongation at breakage for NR/DOMMT-10 were 17.3 MPa and 697%, respectively, which were about 13.8% and 10.8% higher, respectively, compared with that for the pure NR. After the addition of DOMMT, the horizontal burning time increased by about 69% and the thermal stability was also improved. We also propose a possible flame-retardant and reinforcing mechanism for this novel organoclay in an NR matrix.

  18. Computer Simulation of Cure Process of an Axisymmetric Rubber Article Reinforced by Metal Plates Using Extended ABAQUS Code

    Directory of Open Access Journals (Sweden)

    M.H.R. Ghoreishy

    2013-01-01

    Full Text Available Afinite element model is developed for simulation of the curing process of a thick axisymmetric rubber article reinforced by metal plates during the molding and cooling stages. The model consists of the heat transfer equation and a newly developed kinetics model for the determination of the state of cure in the rubber. The latter is based on the modification of the well-known Kamal-Sourour model. The thermal contact of the rubber with metallic surfaces (inserts and molds and the variation of the thermal properties (conductivity and specific heat with temperature and state-of-cure are taken into consideration. The ABAQUS code is used in conjunction with an in-house developed user subroutine to solve the governing equations. Having compared temperature profile and variation of the state-of-cure with experimentally measured data, the accuracy and applicability of the model is confirmed. It is also shown that this model can be successfully used for the optimization of curing process which gives rise to reduction of the molding time.

  19. Application of gamma irradiation for incorporation of rubber powder in the formulations of EPDM and natural rubber; Aplicacao da radiacao gama para incorporacao do po de borracha em formulacoes de borracha natural e EPDM

    Energy Technology Data Exchange (ETDEWEB)

    Kiyan, Ludmila Y.P.; Parra, Duclerc Fernandes; Lugao, Ademar Benevolo, E-mail: ludmilapozzo@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP/CQMA), Sao Paulo, SP (Brazil). Centro de Quimica e Meio Ambiente

    2013-07-01

    The objective of this work was to study the behavior of the recycling of rubber burrs in form of powder, of the rubber industry from EPDM rubber powder and natural rubber with SBR. The rubber powder was irradiated and reused in rubber artifacts formulations for classical vulcanization. The processed material was irradiated using a {sup 60}Co source in doses of 50, 100, 150 and 200 kGy and a dose rate of 5 kGy s-1 at room temperature. The radiation created devulcanization active sites for subsequent integration of the material (rubber powder) in formulations of commercial use. The processes were compared and their products characterized by analytical methods of the physical properties such as strength and elongation. Satisfactory results were found, noting a major spin-off of EPDM chain demonstrated by increased elongation.

  20. Thermal, Morphological and Physic-Mechanical Properties of Natural Rubber - CaCO3 Composites Using Jatropha Oil as Softener.

    Directory of Open Access Journals (Sweden)

    Nasruddin

    2018-01-01

    Full Text Available The urgency of green technology in rubber compounding has become a critical issue recently. In this research, the effect of using renewable resources in rubber compounding has been studied. Commercial Calcium Carbonate, Silica and Jatropha Oil were used in natural rubber composite. The research was designed by varying the types of commercial filler namely CaCO3 (47-51 phr, silica (47-51 phr and Jatropha Oil (4-6 phr in natural rubber composites (SIR-20. The formulas were intentionally designed for rubber tips vulcanizates. The samples were characterized by the determination of physic-mechanical, thermal (TGA and morphological (SEM properties. From the measured results, there is no significant effect on the tensile strength, specific gravity, and hardness on the loading of commercial CaCO3 and Silica in natural rubber composites using Jatropha Oil. However, a slight difference in elongation at break and abrasion resistance could be detected. Compared to the commercial rubber tips, the rubber tips produced in this research have higher tensile strength, elongation at break and abrasion resistance. Due to the usage of commercial CaCO3 and Silica, the SEM micrographs show rough surface because of the agglomeration. The thermogram shows clearly the compositional analysis of the rubber tips vulcanizates consist of Jatropha Oil and natural rubber, CaCO3, ash and other filler residues such as Silica.

  1. A molecular dynamics study on Young's modulus and tribology of carbon nanotube reinforced styrene-butadiene rubber.

    Science.gov (United States)

    Chawla, Raj; Sharma, Sumit

    2018-03-18

    Styrene-butadiene rubber is a copolymer widely used in making car tires and has excellent abrasion resistance. The Young's modulus and tribology of pure styrene butadiene rubber (SBR) polymer and carbon nanotube reinforced polymer composites have been investigated using molecular dynamics simulations. The mechanism of enhanced tribology properties using carbon nanotube has been studied and discussed. The obtained Young's modulus shows the enhancement in mechanical properties of SBR polymer when carbon nanotubes are used as reinforcement. The concentration, temperature and velocity profiles, radial distribution function, frictional stresses, and cohesive energy density are calculated and analyzed in detail. The Young's modulus of SBR matrix increases about 29.16% in the presence of the 5% CNT. The atom movement velocity and average cohesive energy density in the friction area of pure SBR matrix was found to be more than that of the CNT/SBR composite. Graphical abstract Initial and final conditions of (a) pure SBR matrix and (b) CNT/SBR matrix subjected toshear loading and frictional stresses of top Fe layers of both pure SBR and CNT/SBR composite.

  2. Analysis of Aqueous Extractable Protein in Radiation Pre vulcanized Natural Rubber Latex (RVNRL) And Sulphur Pre vulcanized Natural Rubber Latex (SVNRL)

    International Nuclear Information System (INIS)

    Sofian Ibrahim; Mohd Noor Wadi Mat Lazim; Syuhada Ramli; Keong, C.C.; Khairul Hisyam Mohd Yusof; Muhammad Saiful Omar; Najib Mohd Zakey; Hafizuddin Maseri; Noor Hasni Mohd Ali

    2015-01-01

    The use of radiation do not only produces Radiation Pre vulcanized Natural Rubber Latex (RVNRL) that can be used for the production of nitrosamines free products, moreover, RVNRL also able to exclude type IV allergy that caused by high protein content in the products. Leaching water from production of finger coat from RVNRL and Sulphur Pre vulcanized Natural rubber Latex (SVNRL) has been collected. Extractable protein content from water samples measured according to the test protocol ASTM D5712-2010. Water from leaching process of finger coat made from RVNRL showed a higher protein content than SVNRL. This explains why RVNRL based products contain very low protein content and thus reduce the risk of Type IV allergy. (author)

  3. Electron beam cross-linking of natural rubber/linear-low density polyethylene blends

    International Nuclear Information System (INIS)

    Ahmad, A.; Mohd, D. H.; Abdullah, I.

    2005-01-01

    Effects of electron beam irradiation on the mechanical properties and morphological structure of natural rubber/linear-low density polyethylene blend was investigated The natural rubber/linear-low density polyethylene blend was prepared by melt blending in a Haake internal mixer at 140 d ig C , rotor speed of 50 rpm, and in 15 min Liquid natural rubber was incorporated into the blend as a compatibilizer Samples in the form of 1 mm sheets were exposed to 50-300 kGy of electron beam irradiation and analyzed for swelling index and gel content, tensile strength, and surface morphology. The result Indicated that gel content and mechanical properties of the samples increased with radiation dosage. The honey-comb structure of the surface morphology in low dosage irradiated samples slowly transformed into a continuous matrix on increasing radiation dose The variation of mechanical and physical properties was due to Increase in cross-linking density in the rubber and plastic phases and rubber-plastic Interaction on irradiation

  4. Mechanism of n-butyl acrylate sensitization action in radiation vulcanization of natural rubber latex

    International Nuclear Information System (INIS)

    Sabharwal, S.; Chaudhari, C.V.; Bhardwaj, Y.K.; Majali, A.B.; Das, T.N.

    1996-01-01

    In order to understand the role of n-butyl acrylate (nBA) in radiation vulcanization of natural rubber latex, pulse radiolysis technique has been utilized to study the reactions of the transient species produced by reaction of OH . , e- aq and H . atoms with nBA in aqueous solutions. The results show that transients produced by reaction of e- aq with nBA alone are capable of propagating the polymerization reaction and enhance the vulcanization process. These results have been further confirmed by studying the effect of electron scavengers on the vulcanization behaviour of natural rubber latex in presence of nBA. (author). 3 refs., 3 figs

  5. The Effect of Novel Binary Accelerator System on Properties of Vulcanized Natural Rubber

    Directory of Open Access Journals (Sweden)

    Moez Kamoun

    2009-01-01

    Full Text Available The mechanical properties, curing characteristics, and swelling behaviour of vulcanized natural rubber with a novel binary accelerator system are investigated. Results indicate that the mechanical properties were improved. Crosslinking density of vulcanized natural rubber was measured by equilibrium swelling method. As a result, the new binary accelerator was found to be able to improve both cure rate and crosslinking density. Using the numerical analysis of test interaction between binary accelerator and operational modelling of vulcanization-factors experiments, it can be concluded that the interaction (Cystine, N-cyclohexyl-2-benzothiazyl sulfenamide was significant and the optimum value of binary accelerator was suggested, respectively, at levels 0 and +1.

  6. Gamma irradiator design concepts for radiation vulcanisation of natural rubber latex

    International Nuclear Information System (INIS)

    Aggarwal, K.S.; Muralidharan, P.; Apte, M.G.; Kalurkar, A.R.; Shah, B.M.

    1990-01-01

    Radiation vulcanisation of natural rubber latex (NRL) is a new and yet unproven technology and one which involves undefined problems of consumer acceptance and high degree of radiation risk. Therefore, the designer should take care that the initial capital cost of the plant is as low as possible to keep the unit processing cost low during the initial lean period of the product requirement by the market. Three irradiators to process natural rubber latex have been designed as per capacity requirement of the user. Their salient features are described. (author). 2 tabs., 24 figs

  7. Mechanical and morphological properties of kenaf powder filled natural rubber latex foam

    Energy Technology Data Exchange (ETDEWEB)

    Karim, Ahmad Fikri Abdul, E-mail: a.fikri-89@yahoo.com; Ariff, Zulkifli Mohamad [School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang (Malaysia); Ismail, Hanafi [Cluster for Polymer Composites (CPC), Science and Engineering Research Centre, Engineering Campus, Universiti Sains Malaysia,14300 Nibong Tebal, Pulau Pinang (Malaysia)

    2015-07-22

    This research is carried out by incorporate kenaf powder with natural rubber latex (NRL) compound and is foamed to make natural rubber latex foam (NRLF) by using a well known technique called Dunlop method. Different loading of kenaf powder was added to NRL compound and was foamed to make NRLF. The tensile properties, and morphology of kenaf filled NRLF was studied. Increase in kenaf loading reduced the tensile strength and elongation at break and of a compound. Modulus at 100% elongation of the compound increased with increased in filler loading. The morphological and micro structural characterization has been performed by using scanning electron microscopy (SEM)

  8. Mechanical and morphological properties of kenaf powder filled natural rubber latex foam

    International Nuclear Information System (INIS)

    Karim, Ahmad Fikri Abdul; Ariff, Zulkifli Mohamad; Ismail, Hanafi

    2015-01-01

    This research is carried out by incorporate kenaf powder with natural rubber latex (NRL) compound and is foamed to make natural rubber latex foam (NRLF) by using a well known technique called Dunlop method. Different loading of kenaf powder was added to NRL compound and was foamed to make NRLF. The tensile properties, and morphology of kenaf filled NRLF was studied. Increase in kenaf loading reduced the tensile strength and elongation at break and of a compound. Modulus at 100% elongation of the compound increased with increased in filler loading. The morphological and micro structural characterization has been performed by using scanning electron microscopy (SEM)

  9. Influence of acetone extract from natural rubber on the structure and interface interaction in NR/silica composites

    Science.gov (United States)

    Xu, Tiwen; Jia, Zhixin; Wu, Lianghui; Chen, Yongjun; Luo, Yuanfang; Jia, Demin; Peng, Zheng

    2017-11-01

    It is well known that the coupling reagents as the additional modifiers were often used to improve the reinforcement effect of silica filled natural rubber. Actually, the commercial raw NR is a mixture consisting of polyisoprene and non-isoprene, where the latter one might have impact on the properties of NR/silica composites as an inartificial modifier inside. Thus, investigating the effect of non-isoprene compounds on the structure and properties of NR/silica composites is a novel approach to disclose the peculiarity of NR, which is meaningful to the assessment of NR quality. In this paper, the influences of acetone extract (AE) from natural rubber on the structure and mechanical properties of NR/silica composites were studied. Then the interfacial interactions between AE and silica were also illustrated through Fourier transform infrared spectroscopy (FTIR), thermogravimetic analysis (TGA), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Results demonstrated the existence of hydrogen bond between silica and AE, also the covalent bond induced by esterification reaction between sbnd COOH and Sisbnd OH, which resulted in an increase of constrained regions around silica surface leading to the promotions on mechanical and dynamical properties of NR/silica composites significantly.

  10. Development of natural rubber membranes for separation of methyl tert-butyl ether and methanol

    International Nuclear Information System (INIS)

    Nur Azrini Ramlee; Ghazali Mohd Nawawi; Khairul Zaman Dahlan

    2010-01-01

    As a new commercial process, membrane separation raises significant expectations in the process plant of the future and therefore this research was being initiated to develop and characterize pervaporation membrane based on natural rubber (NR). Natural Rubber SMR-L grade which was supplied by Malaysia Rubber Research Institute (MRRI) was used for the development of the membranes via interpenetrating polymer network (IPN) techniques. Polystyrene (PS) was used to modify the natural rubber to further improve their mechanical and chemical properties. The membranes were prepared with various blend ratios of natural rubber, polystyrene and divinyl benzene as cross linker with constant 1 % of dicumyl peroxide as the initiator. The developed membranes were then characterized to study the functional group presence, membranes morphology, crosslink density, tear strength, adsorption of the membranes and pervaporation separation of Methyl-Tert-Butyl-Ether (MTBE) and Methanol. Pervaporation process was conducted by using varies of MTBE concentration 10, 30, 50 and 70 wt % and at differ operation temperature, 25 degree Celsius and 55 degree Celsius. Separation performance of IPN NR/ PS membranes were based on the presented permeation flux and separation factor. Examination through Fourier Transform Infrared Spectroscopy (FTIR), determined crosslink density and tear strength, 6 series of IPN NR/ PS membranes were successfully developed using natural rubber. Observation from Scanning Electron Microscopy (SEM) showed that the membranes were dense and appropriated for the pervaporation process application. From the pervaporation of MTBE and Methanol, IPN NR/ PS membranes of series D4N30 shown low permeation flux of MTBE but high separation factor while D2N70 membranes was vice versa for both temperature of 25 degree Celsius and 55 degree Celsius. (author)

  11. Pilot Scale Production of Irradiated Natural Rubber Latex and its Dipping Products

    Directory of Open Access Journals (Sweden)

    M. Utama

    2005-07-01

    Full Text Available One hundred and fifty kg natural rubber latex (NRL before and after concentration were added with 3 phr (part hundred ratio of rubber normal butyl acrylate, then the mixture were irradiated at 25 kGy by gamma rays of 60Co in pilot scale. The irradiated natural rubber latex (INRL were then being to use for producing rubber products such as condom, surgical gloves, and spygmomanometer in factory scale. The quality of INRL and rubber products such as : total solid content (TSC, dry rubber content (DRC, KOH, VFA and MST number, tensile strength, modulus, elongation at break, extractable protein content, and response against Type I allergy etc. were evaluated. The economic aspect for producing INRL by means of Gamma Irradiator (GI and Electron Beam Machine (EBM such as payback period (PP, net present value (NPV and internal rate return (IRR were calculated. The results showed that the latex properties of INRL such as DRC, TSC, KOH, VFA, and MST number are not only found to the requirement of the ISO 2004 standard but also the latex has low protein, lipid, and carbohydrate content. The physical and mechanical properties (tensile strength, modulus, and elongation at break of rubber dipping products such as condom, gloves, and sphygmomanometer are not only found to the requirement of ISO 4074, ISO 10282, and ANSI/AAMI SP-1994 standards, but also the allergic response tested clinical latex-sensitive protein allergen by ELISA test on gloves, and by SPT test on condom are found to be negative. It indicates that production of INRL or PVNRL or RVNRL by EBM 250 keV/10 mA, was more cheap than by using gamma γ irradiator 200 kCi, or sulfur vulcanization. The value of PBP (payback period was 2,1 years, NPV (net present value was 4,250 US $, PI (profitability index 1,06 and IRR (internal rate of returns was 25,0%.

  12. Structural and physico-mechanical properties of natural rubber/GTR composites devulcanized by microwaves: influence of GTR source and irradiation time

    OpenAIRE

    Colom Fajula, Xavier; Marin-Genesca, Marc; Mujal Rosas, Ramón María; Formela, Krzysztof; Cañavate Ávila, Francisco Javier

    2018-01-01

    Ground tire rubber from car and truck was modified using microwave irradiation at variable time. The irradiated ground tire rubber was used as filler in composites based on natural rubber. The composites, with high content of ground tire rubber, were prepared using an internal batch mixer and subsequently cross-linked at 160¿. The influence of the ground tire rubber source (car/truck) and irradiation time on structure, physico-mechanical behaviour, thermal properties and morphology of natural...

  13. Natural rubber latex: determination and interpretation of flow curves

    Directory of Open Access Journals (Sweden)

    Harrison Lourenço Corrêa

    2015-08-01

    Full Text Available AbstractAs consumers become more demanding, the importance grows of guaranteeing the quality of products. The employment of reliable testing techniques that assure the origin and characteristics of the inputs used by industry is a key factor in this respect. In the rubber processing industry, the most commonly used characterization tests include determination of the total solids and dry rubber content, mechanical stability, odor, color and presence of volatile compounds, among others. For the most part, these tests are sufficient for the latex transformation industry. However, in situations where there is a need to know the behavior of latex in reaction to the mechanical forces of machines (mixers, pumps, etc., other tests must be used. Rheological tests to determine viscoelastic data by means of plotting flow curves combined with the application of theoretical models can provide important details for characterization of different types of latex. This article presents the protocol employed by the Rheology and Image Laboratory of Rio de Janeiro State University (UERJ for the rheological study of Brazilian latex. The samples analyzed came from the state of São Paulo.

  14. Extractable protein of radiation vulcanized natural rubber latex

    International Nuclear Information System (INIS)

    Soebianto, Y.S.; Ratnayake, U.M.; Makuuchi, Keizo; Yoshii, Fumio; Kume, Tamikazu

    2000-01-01

    Protein remained in the latex products are reported to cause serious allergy. A new method to reduce the protein level in the latex products by irradiation is reported. Water soluble protein (WSP) solution (10%) was added into radiation vulcanized NR latex (RVNRL) in three different processes. The amount of WSP was 3 phr. It was only added to RVNRL (standard), added to re-centrifuged RVNRL (pre-centrifugation), and added to RVNRL followed by centrifugation (post-centrifugation). The protein content was determined by enhanced BCA method, and identified by SDS-PAGE. Extractable protein (EP) from the rubber has been reduced up to the minimum protein detection by combining WSP addition and centrifugation. Short leaching time (20-30 min.) can be achieved after the combine treatment, and SDS-PAGE confirms the reduction of soluble protein in the serum phase, and disappearance of protein bands in the rubber extract. Protein-WSP interaction produces water soluble complex, and removed by centrifugation. The efficiency of protein removal by WSP depends on its molecular weight of WSP which relates to its water solubility. (author)

  15. The effect of proteins on the aging properties of radiation vulcanized natural rubber latex

    International Nuclear Information System (INIS)

    Abad, L.V.

    1993-01-01

    The effect of natural rubber latex (NRL) proteins on the aging properties of NRL films was investigated. SDS-PAGE electrophoresis of the rubber proteins in NRL (Sri-Lanka) indicated a total of 18 proteins. A sharp decrease in tensile strength was observed after aging when NRL films were leached in 1% NH 4 OH. However, when these films were soaked in ethanol prior to leaching, the aging properties approximated those of the unleashed samples. Electrophoretic analysis of the proteins present in the NH 3 extracts of leached RVNRL films showed a high concentration of the protein herein. This protein was not found in the NH 3 extracts of ethanol soaked films. NRL proteins were shown to decelerate the aging process of Radiation Vulcanized Natural Rubber Latex (RVNRL) films. Among the proteins, herein exhibited good anti-aging properties. The hydrolyzates from NR proteins also enhanced considerably the aging properties of RVNRL. (auth.). 8 refs.; 40 figs.; 30 tabs

  16. Trialed production of low protein irradiated natural rubber latex in factory scale by gamma irradiation technique

    International Nuclear Information System (INIS)

    Utama, Marga; Herwinarni, S.; Halik, H.M.; Siswanto; Suharyanto; Syamsu, Y.; Handoko, B.

    2006-01-01

    Four tons fresh field natural rubber latex (FNRL) with total solid content 30% were added with 2 phr (part hundred ratio of rubber) normal butyl acrylate (nBA) then irradiated by gamma rays at 25 kGy. The irradiated FNRL was centrifuged, then the properties of irradiated centrifuged natural rubber latex (INRL) and its film were measured before and after storage for 5 months. It is found that the INRL is stable latex during storage in 5 months, with lowest protein, and free nitrosamine content. The tensile strength of INRL film was 24-27 MPa, and modulus 600% was 1,5-2,0 MPa, elongation at break was 900%, and hardness was 27-29 Shore A, while the extractable protein content less than 100 μg/g. (author)

  17. Exploiting epoxidized natural rubber latex (ENRL) as a starting raw material for latex-based products

    Science.gov (United States)

    Siti Nor Qamarina, M.; Fatimah Rubaizah, M. R.; Nurul Suhaira, A.; Norhanifah, M. Y.

    2017-12-01

    Epoxidized natural rubber latex (ENRL) is a chemically modified natural rubber latex produced from epoxidation process that involves usage of organic peracids. Conversion of the ENRL into dry rubber products has been known to exhibit many beneficial properties, however limited published works were found on diversifiying the ENRL latex-based products applications. In this preliminary work, different source of raw materials and neutralization systems were investigated. The objective was to explore possibilities in producing distinctive ENRL. Findings have demonstrated that different source of raw materials and neutralization systems influenced the typical ENRL specifications, stability behavior and particle size distribution. Morphological observations performed on these ENRL systems appeared to agree with the ENRL characteristics achieved. Since experimenting these two main factors resulted in encouraging ENRL findings, detailed work shall be further scrutinized to search for an optimum condition in producing marketable ENRL specifically for latex-based products applications.

  18. Rubber compounding and processing

    CSIR Research Space (South Africa)

    John, MJ

    2014-06-01

    Full Text Available This chapter presents an overview on the compounding and processing techniques of natural rubber compounds. The introductory portion deals with different types of rubbers and principles of rubber compounding. The primary and secondary fillers used...

  19. Irradiation grafting of natural rubber latex with maleic anhydride and its compatibilization of poly(lactic acid)/natural rubber blends

    Science.gov (United States)

    Pongsathit, Siriwan; Pattamaprom, Cattaleeya

    2018-03-01

    Maleic anhydride (MA) is an interesting monomer to be grafted onto natural rubber(NR) due to its potential as a compatibilizer of hydrophobic rubbers and polymers with higher polarity. So far, radiation grafting of MA onto NR in latex state has not been reported. In this study, the grafting of NR with MA in latex state was investigated by exposing the latex to cobalt-60 gamma irradiation at a fixed MA content of 9% and a varied absorbed doses from 2 to 10 kGy. The FTIR spectrometer, 1H NMR spectrometer and gel content analysis have confirmed successful grafting of MA onto NR after irradiation. The grafted NRs were then used to increase the compatibility and the impact property of PLA/NR blends. It was found that the highest impact strength of the blends was achieved when the grafting was carried out at the absorbed dose of 4 kGy.

  20. Effect of cellulose nanocrystals from corn cob with dispersion agent polyvinyl pyrrolidone in natural rubber latex film after aging treatment

    Science.gov (United States)

    Harahap, H.; Ridha, M.; Halimatuddahliana; Taslim; Iriany

    2018-02-01

    This study about the resistance of natural rubber latex films using nanocrystals cellulose filler from corn cob waste by aging treatment. Corn cob used as organic filler composed of cellulose, hemicellulose, and lignin. Each component has a potential for reuse, such as cellulose. Cellulose from corn cob has potential application as a filler prepared by hydrolysis process using a strong acid. The producing of natural rubber latex films through coagulant dowsing process. This research started with the pre-vulcanization process of natural rubber latex at 70 °C and followed by process of vulcanization at 110 °C for 20 minutes. Natural rubber latex films that have been produced continued with the aging treatment at 70 °C for 168 hours. The mechanical properties of natural rubber latex films after aging treatment are the tensile strength, elongation at break, M100 and M300 have performed.

  1. Extractable protein of radiation vulcanized natural rubber latex

    International Nuclear Information System (INIS)

    Soebianto, Y.S.; Upul, R.M.; Makuuchi, K.; Yoshii, F.; Kume, T.

    2000-01-01

    A new method to reduce the protein level in the latex products by irradiation is reported. Water soluble protein (WSP) solution (10%) was added into radiation vulcanized NR latex (RVNRL) as much as 3 phr in three different processes: added to RVNRL, added to re-centrifuged RVNRL, and added to RVNRL followed by centrifugation. The protein content was determined by enhanced BCA method, and identified by SDS-PAGE analysis. Addition of WSP followed by centrifugation reduces EP up to the minimum protein detection, and shortens the leaching time to 20-30 min. SDS-PAGE analysis confirms the reduction of soluble protein in the serum phase, and disappearance of protein bands in the rubber extract. Protein-WSP interaction produces water soluble complex, and removed by centrifugation. The molecular weight of WSP dictates the efficiency of protein removal. (author)

  2. Evaluation of Cooking Oil as Processing Addtive for Natural Rubber

    Directory of Open Access Journals (Sweden)

    Y. M. SYAMIN

    2017-08-01

    Full Text Available It was reported recently that high amount of aromatic ring  or number of polycyclic aromatic hydrocarbon compounds found in aromatic oil are carcinogenic. This paper discusses the work to evaluate the Malaysian cooking oil as an alternative option to be used as process oil since cooking oil is safe to use and non-toxic. The performance of cooking oil is compared againstaromatic and paraffinioils. The results showed that rubber compounds containing cooking oil produced almostsimilar cure characteristicsas those produced by aromatic and paraffinioils indicating that it did not interfere with the vulcanization reaction. The physical properties of the vulcanizates containing cooking oil were almostsimilar to those of vulcanizates containing aromatic and paraffinioils, except the rebound resilience. The vulcanizates containing cooking oil gave higher resilience than vulcanizates containing aromatic and paraffinioils. High resilience is one of the desired features for a low rolling resistance tyre. Cooking oil provided this extra advantage.

  3. Extractable protein of radiation vulcanized natural rubber latex

    Energy Technology Data Exchange (ETDEWEB)

    Soebianto, Y.S. [Center for Research and Development of Isotopes and Radiation Technology, BATAN, Jakarta (Indonesia); Upul, R.M. [Rubber Research Institute of Sri Lanka, Ratmalana (Sri Lanka); Makuuchi, K.; Yoshii, F.; Kume, T. [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2000-03-01

    A new method to reduce the protein level in the latex products by irradiation is reported. Water soluble protein (WSP) solution (10%) was added into radiation vulcanized NR latex (RVNRL) as much as 3 phr in three different processes: added to RVNRL, added to re-centrifuged RVNRL, and added to RVNRL followed by centrifugation. The protein content was determined by enhanced BCA method, and identified by SDS-PAGE analysis. Addition of WSP followed by centrifugation reduces EP up to the minimum protein detection, and shortens the leaching time to 20-30 min. SDS-PAGE analysis confirms the reduction of soluble protein in the serum phase, and disappearance of protein bands in the rubber extract. Protein-WSP interaction produces water soluble complex, and removed by centrifugation. The molecular weight of WSP dictates the efficiency of protein removal. (author)

  4. A novel use of bio-based natural fibers, polymers, and rubbers for composite materials

    Science.gov (United States)

    Modi, Sunny Jitendra

    The composites, materials, and packaging industries are searching for alternative materials to attain environmental sustainability. Bio-plastics are highly desired and current microbially-derived bio-plastics, such as PHA (poly-(hydroxy alkanoate)), PHB (poly-(hydroxybutyrate)), and PHBV (poly-(beta-hydroxy butyrate-co-valerate)) could be engineered to have similar properties to conventional thermoplastics. Poly-(hydroxybutyrate) (PHB) is a bio-degradable aliphatic polyester that is produced by a wide range of microorganisms. Basic PHB has relatively high glass transition and melting temperatures. To improve flexibility for potential packaging applications, PHB is synthesized with various co-polymers such as Poly-(3-hydroxyvalerate) (HV) to decrease the glass and melting temperatures and, since there is improved melt stability at lower processing temperatures, broaden the processing window. However, previous work has shown that this polymer is too brittle, temperature-sensitive, and hydrophilic to meet packaging material physical requirements. Therefore, the proposed work focuses on addressing the needs for bio-derived and bio-degradable materials by creating a range of composite materials using natural fibers as reinforcement agents in bio-polymers and bio- plastic-rubber matrices. The new materials should possess properties lacking in PHBV and broaden the processing capabilities, elasticity, and improve the mechanical properties. The first approach was to create novel composites using poly-(beta-hydroxy butyrate-co-valerate) (PHBV) combined with fibers from invasive plants such as common reed (Phragmites australis), reed canary grass (Phalaris arundinacea), and water celery ( Vallisneria americana). The composites were manufactured using traditional processing techniques of extrusion compounding followed by injection molding of ASTM type I parts. The effects of each bio-fiber at 2, 5, and 10% loading on the mechanical, morphological, rheological, and thermal

  5. Properties of organo-clay/natural rubber nanocomposites: effects of organophilic modifiers

    Czech Academy of Sciences Publication Activity Database

    Hrachová, J.; Komadel, P.; Jochec-Mošková, D.; Krajči, J.; Janigová, I.; Šlouf, Miroslav; Chodák, I.

    2013-01-01

    Roč. 127, č. 5 (2013), s. 3447-3455 ISSN 0021-8995 R&D Projects: GA ČR GAP205/10/0348 Institutional research plan: CEZ:AV0Z40500505 Keywords : nanocomposite s * natural rubber * morphology Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.640, year: 2013

  6. Properties of natural rubber composites with structurally different clay intercalable surfactants

    Czech Academy of Sciences Publication Activity Database

    Sedničková, M.; Jochec-Mošková, D.; Janigová, I.; Kronek, J.; Jankovič, L.; Šlouf, Miroslav; Chodák, I.

    2017-01-01

    Roč. 24, č. 7 (2017), s. 1-13, č. článku 105. ISSN 1022-9760 Institutional support: RVO:61389013 Keywords : composite * natural rubber * clay Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 1.615, year: 2016

  7. Structural and Magnetic Properties of Type-M Barium Ferrite - Thermoplastic Natural Rubber Nano composites

    International Nuclear Information System (INIS)

    Nurhidayaty Mokhtar

    2012-01-01

    Structural and magnetic properties of type-M barium ferrite (BaFe 12 O 19 ) nanoparticles (∼ 20 nm) embedded in non-magnetic thermoplastic natural rubber (TPNR) matrices were investigated. The TPNR matrices were prepared from high density polyethylene (HDPE) and natural rubber (NR) in the weight ratios of 80:20 and 60:40, respectively, with 10 wt % of NR in the form of liquid natural rubber (LNR) which act as a comparabilities. BaFe 12 O 19 - filled nano composites with 2 - 12 wt % BaFe 12 O 19 ferrite were prepared using a melt- blending technique. Magnetic hysteresis was measured using a vibrating sample magnetometer (VSM) in a maximum field of 10 kOe at room temperature (25 degree Celsius). The saturation magnetisation (MS), remanence (MR) and coercivity (Hc) were derived from the hysteresis loops. The results show that the structural and magnetic properties of nano composites depend on both the ferrite content and the composition of the natural rubber or plastic in the nano composites. All the nano composites exhibit an exchange bias-like phenomenon resulting from the exchange coupling of spins at the interface between the core ferrimagnetic region and the disordered surface region of the nanoparticles. (author)

  8. Effect of Antioxidants on Radiation Vulcanization Natural Rubber Latex (RVNRL) Film

    International Nuclear Information System (INIS)

    Syuhada Ramli; Sofian Ibrahim; Muhammad Saiful Omar

    2015-01-01

    This paper presents the results on the effects of different antioxidants used in Radiation Vulcanization Natural Rubber Latex (RVNRL)) films between 0 to 10 weeks monitoring. Antioxidants used for the RVNRL formulation were Aquanox LP, Irganox and Wingstay L. Color difference evaluation by using Chroma Meter CR-400 found that RVNRL film with Irganox was the most stained yellowish after 8 weeks monitoring. Tensile strength for RVNRL with Aquanox found achieved the optimum strength between 25.4 to 27.13 mPa. The scanner electron microscopic (SEM) indicated more Aquanox molecules to penetrate and interact with the rubber molecule, thus becoming more effective inhibitor against its oxidative ageing. (author)

  9. STUDIES ON NATURAL WEATHERING OF RATTAN POWDER-FILLED NATURAL RUBBER COMPOSITES

    Directory of Open Access Journals (Sweden)

    Komethi Muniandy,

    2012-07-01

    Full Text Available This article investigates the effect of natural weathering on mechanical and morphological properties of rattan powder-filled natural rubber (NR composites as a function of filler loading and silane coupling agent. The rattan powder samples in the range of 0 to 30 phr were compounded with NR using a laboratory size two-roll mill. The natural weathering test was carried out for six months. The degradation of the samples was evaluated by performing a tensile test, a Fourier transform infrared spectroscopy (FTIR, and a scanning electron microscopy (SEM test. The results indicated that after natural weathering, an increase in stress at 100% elongation (M100 can be seen for samples without the silane coupling agent, whilst M100 was reduced for samples with silane coupling agent. A drastic reduction in tensile strength and elongation at break were observed for all samples due to the photo-oxidation process that occurred during the degradation of the samples. The extent of degradation on the samples’ surfaces and the presence of oxygenated products were confirmed by SEM and FTIR studies, respectively.

  10. Antioxidant and sensitizer effect on the stability of natural rubber latex vulcanized by gamma rays

    International Nuclear Information System (INIS)

    Canavel, V.

    1993-01-01

    The natural rubber latex was vulcanized by gamma rays and electrons beam, in the presence and absence of sensitizer at room temperature. The sensitizers were the following; n-butyl acrylate (n-BA) / t-butyl hydroperoxide (t-B H) / KOH, C Cl 4 / potassium laurate and n-BA / KOH. The studied antioxidants, Irganox 1520, Vulcanox SP and Vulcanox BKF, were added to the latex after irradiation. Among the studied antioxidants in function of tensile strength (TS) after the aging of rubber plates, the Irganox was the best efficient on the gamma vulcanization in the presence of n-BA/t-B H/KOH, because only 0,20 p hr is enough to obtain the greatest increase of TS, that was 34%, 12 MPa to 16 MPa. The formulating method of latex with the sensitizer constituted the 3,0 p hr of n-BA/ 0,1 p hr of t-B H and 0,2 p hr of KOH, was evaluated respecting the TS of rubber plates. The electrons beam vulcanization produces the greatest reversible perturbance in the colloidal stability of latex after irradiation caused by radiolytic species absorption that promotes the increase of particle size. The antioxidant also contributes to reversible destabilization of gamma irradiated latex, because it is also adsorbed by particles surface. The relation between the latex viscosity and the TS of respective rubber plates is reverse, showing the latex stability affects the quality of rubber goods. (author)

  11. Surface modification of silica particles and its effects on cure and mechanical properties of the natural rubber composites

    Energy Technology Data Exchange (ETDEWEB)

    Theppradit, Thawinan [Program in Petrochemistry and Polymer Science, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Prasassarakich, Pattarapan [Department of Chemical Technology, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Poompradub, Sirilux, E-mail: sirilux.p@chula.ac.th [Department of Chemical Technology, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand)

    2014-12-15

    The efficiency of modified silica (SiO{sub 2}) particles in the reinforcement of natural rubber (NR) vulcanizates was evaluated. The SiO{sub 2} particles were synthesized via a sol–gel reaction using tetraethyl orthosilicate as the precursor, and then the formed SiO{sub 2} particles were modified with methyl, vinyl or aminopropyl groups using methyltriethoxysilane, vinyltriethoxysilane or aminopropyltrimethoxysilane, respectively. Fourier transform infrared spectroscopy and elemental analysis confirmed the successful modification of the surface of the silica particles. The water contact angle measurement revealed the greater hydrophobicity of the three modified silica preparations compared to the unmodified SiO{sub 2}. NR vulcanizates filled with modified SiO{sub 2} particles were prepared and the mechanical, thermal and dynamic mechanical properties of composites were investigated. The morphology of composite materials was also investigated by scanning electron microscopy. The modified SiO{sub 2} particles were well dispersed in the NR matrix leading to the good compatibility between the rubber and filler, and so an improved cure, mechanical, thermal and dynamic mechanical properties of the composite vulcanizate materials. - Highlights: • Modification of SiO{sub 2} particles by MTES, VTES and APTES. • Improvement of hydrophobicity of SiO{sub 2} particle and compatibility between SiO{sub 2} and rubbery matrix. • Improvement of cure, mechanical, thermal, dynamic mechanical properties of NR vulcanizates.

  12. Proceedings of the international symposium on radiation vulcanization of natural rubber latex

    International Nuclear Information System (INIS)

    Machi, Sueo

    1990-01-01

    The First International Symposium on Radiation Vulcanization of Natural Rubber Latex (RVNRL) was held from 26 to 28 July 1989 at Tokyo and Takasaki. In these proceedings, thirty six papers presented at the Symposium are compiled. Main topics are commercial application of RVNRL, characterization of NR latex and vulcanization, properties of radiation vulcanized NR latex, development of sensitizers, mechanism of RVNRL, RVNRL with electron beams, and new Co-60 irradiator for RVNRL. Absence of nitrosamines and low cytotoxicity of radiation vulcanized NR latex are recognized as the remarkable advantages of RVNRL. The radiation vulcanization process for the production of protective rubber gloves for radioactive contamination was presented as the first commercial success in RVNRL. It was reported that various kinds of rubber articles for medical uses have being developed in West Germany. A sensitizer system consisting of n-butyl acrylate and t-butyl hydroperoxide was found to reduce the vulcanization dose to 8 kGy. (author)

  13. Performance of Lightweight Natural-Fiber Reinforced Concrete

    OpenAIRE

    Hardjasaputra Harianto; Ng Gino; Urgessa Girum; Lesmana Gabriella; Sidharta Steven

    2017-01-01

    Concrete, the most common construction material, has negligible tension capacity. However, a reinforcement material such as natural fibers, can be used to improve the tensile properties of concrete. This paper presents experiments conducted on Super Lightweight Concrete mixed with coconut fibers (SLNFRC). Coconut fibers are regarded as one of the toughest natural fibers to strengthen concrete. Coconut fiber reinforced composites have been considered as a sustainable construction material beca...

  14. Utilization of waste expanded polystyrene: Blends with silica-filled natural rubber

    International Nuclear Information System (INIS)

    Sekharan, Renju Vaikathusseril; Abraham, Beena Thattekatt; Thachil, Eby Thomas

    2012-01-01

    Highlights: ► Tensile strength of the silica filled blend is comparable with silica filled NR. ► Modulus and compression set were the best for compatibilized NR/EPS blends. ► Tear strength has increased by 25% for compatibilized blends. ► A 5% waste EPS can be incorporated into NR compounds as a waste management measure. -- Abstract: Expanded polystyrene (EPS) constitutes a considerable part of thermoplastic waste in the environment in terms of volume. In this study, this waste material has been utilized for blending with silica-reinforced natural rubber (NR). The NR/EPS (35/5) blends were prepared by melt mixing in a Brabender Plasticorder. Since NR and EPS are incompatible and immiscible a method has been devised to improve compatibility. For this, EPS and NR were initially grafted with maleic anhydride (MA) using dicumyl peroxide (DCP) to give a graft copolymer. Grafting was confirmed by Fourier Transform Infrared Spectroscopy (FTIR) spectroscopy. This grafted blend was subsequently blended with more of NR during mill compounding. Morphological studies using Scanning Electron Microscopy (SEM) showed better dispersion of EPS in the compatibilized blend compared to the noncompatibilized blend. By this technique, the tensile strength, elongation at break, modulus, tear strength, compression set and hardness of the blend were found to be either at par with or better than that of virgin silica filled NR compound. It is also noted that the thermal properties of the blends are equivalent with that of virgin NR. The study establishes the potential of this method for utilising waste EPS.

  15. Molecular Diffusion of Toluene through CaCO3-Filled Natural Rubber Composites

    Directory of Open Access Journals (Sweden)

    Hedayatollah Sadeghi Ghari

    2012-12-01

    Full Text Available The transport properties of liquids and gases through polymeric materialsplay a very important role in some areas of industrial applications. In thisstudy, natural rubber (NR/CaCO3 composites were prepared by melt mixingmethod. By equilibrium swelling test, the transport process of toluene in the prepared natural rubber composites was investigated. The diffusion and transport of toluene through calcium carbonate-filled natural rubber composites have been studied in the temperature range 25–45°C. The diffusion of toluene through these composites was studied with special reference to the effect of filler concentration and temperature.The transport coefficients such as diffusion, permeation and sorption coefficients were estimated from the swelling data. To find out the mechanism of diffusion in prepared composites, the results of swelling studies were applied to an empirical equation. In these composites, diffusion is approximately based on Fickian diffusion mechanism and by increases in temperature; diffusion mechanism is more close to Fickian mechanism. Increase of filler content in composite would result in decreased ultimateswelling and slower diffusion rate of solvent. The diffusion rate, diffusion coefficient and the permeability increased by temperature. The study of the diffusion of toluene through filled natural rubber indicated that the concentration of filler plays an important role in the diffusion, sorption and permeation coefficients. Also interfacial interactions in NR composites were checked by dynamic-mechanical analysis. The microstructure and dispersion of calcium carbonate particles in natural rubber matrix were studiedby field emission scanning electron microscopy (FE-SEM. In general, the results of swelling tests, dynamic-mechanical analysis and FE-SEM images show that the optimized value of filler in NR composites is equal to 10 phr calcium carbonate.

  16. Natural rubber, a potential alternative source for the synthesis of renewable fuels via Hydrous Pyrolysis

    Science.gov (United States)

    Ahmad, N.; Dayana, S. A. S.; Abnisa, F.; Mohd, W. A. W. D.

    2018-03-01

    Natural rubber is a humid agricultural harvest, which mostly contains hydrocarbon cis-1, 4-Poly isoprene. Through depolymerisation technology, the natural rubber can be changed into liquid product, and then it can be subsequently utilized as a fuel or chemical feedstock. This article aims to provide an outlook on the natural rubber and its sources, which are available globally. Numerous depolymerisation processes, which include pyrolysis, gasification, chemical degradation, catalytic cracking and hydrogenation, were introduced in this paper, while the focus of discussion was emphasized on the hydrous pyrolysis process. Many studies have shown that the use of hydrous pyrolysis able to improve the depolymerisation process, e.g. the raw material can be feed without drying, the process can be carried out at lower temperature, only the water is used as the reaction medium, and it is easy to separate the water from oil product. The effect of operating parameters such as temperature, water to rubber mass ratio, reaction time and type of gases on the product yield and composition were reviewed in this paper. In addition, this paper also highlighted the eco-friendly and economic viability of the hydrous pyrolysis process.

  17. Reinforcing styrene butadiene rubber with lignin-novolac epoxy resin networks

    Directory of Open Access Journals (Sweden)

    P. Yu

    2015-01-01

    Full Text Available In this study, lignin-novolac epoxy resin networks were fabricated in the styrene butadiene rubber (SBR matrix by combination of latex compounding and melt mixing. Firstly, SBR/lignin compounds were co-coagulated by SBR latex and lignin aqueous solution. Then the novolac epoxy resin (F51 was added in the SBR/lignin compounds by melt compounding method. F51 was directly cured by lignin via the ring-opening reaction of epoxy groups of F51 and OH groups (or COOH groups of lignin during the curing process of rubber compounds, as was particularly evident from Fourier transform infrared spectroscopy (FTIR studies and maximum torque of the curing analysis. The existence of lignin-F51 networks were also detected by scanning electron microscope (SEM and dynamic mechanical analysis (DMA. The structure of the SBR/lignin/F51 was also characterized by rubber process analyzer (RPA, thermogravimetric analysis (TGA and determination of crosslinking density. Due to rigid lignin-F51 networks achieved in SBR/lignin/F51 composites, it was found that the hardness, modulus, tear strength, crosslinking density, the temperature of 5 and 10% weight-loss were significantly enhanced with the loading of F51.

  18. Mechanical and Morphological Properties of Short Nylon Fiber Reinforced Acrylonitrile-Butadiene Rubber Composites

    Directory of Open Access Journals (Sweden)

    S.H. Mohseniyan

    2010-12-01

    Full Text Available Acrylonitrile butadiene rubber (NBR composites are prepared from waste nylon 66 short fiber using a two-roll mill mixer. The effects of fiber content and bonding agent on the mechanical and morphological properties of the composites are studied. The curing characteristics of the composites have been studied by using cure rheometer. The cure and scorch time of the composites decrease while cure rate is increased when short fiber content is increased. The mechanical properties of the composites show improvement in both longitudinal and transverse directions with increase in short fiber content. The adhesion between the fiber and rubber is enhanced by using a dry bonding system consisting of resorcinol, xamethylenetetramine and hydrated silica (HRH. The swelling behavior of the composites in N,N-dimethylformamide is tested to find the effect of bonding agent on adhesion strength of the matrix and fibers. Fracture surface morphology of composites is studied by scanning electron microscopy. The restriction to swelling is higher for composites containing bonding agent, especially, in the longitudinal direction. The morphology of the fracture surface shows less fiber pull out when the bonding agent is introduced.

  19. Energy efficiency enhancement of natural rubber smoking process by flow improvement using a CFD technique

    International Nuclear Information System (INIS)

    Tekasakul, Perapong; Promtong, Machimontorn

    2008-01-01

    A non-uniform flow and large temperature variation in a natural rubber smoking-room cause an inefficient use of energy. Flow uniformity and temperature variation can be improved by using a computational fluid dynamics (CFD) simulation. The effects of the size, position and number of gas supply ducts and ventilating lids which were at the inlets and the outlets of the smoking-room were investigated. The optimal rubber smoking-room of size 2.6 m x 6.2 m x 3.6 m contains 154 50 mm-diameter hot gas supply ducts, and four 0.25 x 0.25 m and four 0.25 x 0.20 m ventilating lids. The velocity distribution of this model in the rubber-hanging area was rather uniform. The average monitoring temperature of 54 positions was 62.1 deg. C. This model could reduce the temperature variation by a factor of three from the original room model, i.e., from 15 to 5.5 deg. C. In a further study, the heat input of an appropriate room model was finely adjusted to obtain a suitable temperature (60 deg. C) for the smoking process. It was found that an appropriate heat supply at this temperature is 11 kW. At this rate, the temperature variation is 5.3 deg. C. This improved model should help the rubber smoking cooperatives to achieve at least a 31.25% saving in energy

  20. Energy efficiency enhancement of natural rubber smoking process by flow improvement using a CFD technique

    Energy Technology Data Exchange (ETDEWEB)

    Tekasakul, Perapong [Energy Technology Research Center and Department of Mechanical Engineering, Faculty of Engineering, Prince of Songkla University, Hat Yai, Songkhla 90112 (Thailand)], E-mail: perapong.t@psu.ac.th; Promtong, Machimontorn [Division of Mechanical Engineering, School of Engineering and Resources, Walailak University, Nakhon Si Thammarat 80160 (Thailand)

    2008-09-15

    A non-uniform flow and large temperature variation in a natural rubber smoking-room cause an inefficient use of energy. Flow uniformity and temperature variation can be improved by using a computational fluid dynamics (CFD) simulation. The effects of the size, position and number of gas supply ducts and ventilating lids which were at the inlets and the outlets of the smoking-room were investigated. The optimal rubber smoking-room of size 2.6 m x 6.2 m x 3.6 m contains 154 50 mm-diameter hot gas supply ducts, and four 0.25 x 0.25 m and four 0.25 x 0.20 m ventilating lids. The velocity distribution of this model in the rubber-hanging area was rather uniform. The average monitoring temperature of 54 positions was 62.1 deg. C. This model could reduce the temperature variation by a factor of three from the original room model, i.e., from 15 to 5.5 deg. C. In a further study, the heat input of an appropriate room model was finely adjusted to obtain a suitable temperature (60 deg. C) for the smoking process. It was found that an appropriate heat supply at this temperature is 11 kW. At this rate, the temperature variation is 5.3 deg. C. This improved model should help the rubber smoking cooperatives to achieve at least a 31.25% saving in energy.

  1. Mechanical property test of natural rubber bearing for the evaluation of uncertainty value of seismic isolation devices

    International Nuclear Information System (INIS)

    Kim, Min Kyu; Kim, Jung Han; Choi, In Kil

    2012-01-01

    Seismic safety of NPP is one of the most important issues in a nuclear field after great east Japan earthquake in 2011. For the improvement of seismic safety of nuclear power plant, seismic isolation is the easiest solution for increasing the seismic safety. Otherwise, the application of seismic isolation devices for nuclear power plants doesn't make the seismic risk of NPP increases always. The rubber bearing have many uncertainties of material properties and large displacement should absorb according to the application of isolation devices. In this study, for the evaluation of uncertainty of the material properties of rubber bearing, material tests for rubber and mechanical properties test for natural rubber bearing were performed. For the evaluation of effect of hardness of rubber, 4 kinds of rubber hardness for material property tests and 2 kinds of rubber hardness for mechanical property test were considered. As a result, the variation of material properties is higher than that of mechanical properties of natural rubber bearings

  2. Effect of epoxidation on 30% poly(methyl methacrylate)-grafted natural rubber polymer electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Nazir, Khuzaimah; Aziz, Ahmad Fairoz [Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia); Adam, Nurul Ilham [Faculty of Applied Sciences, Universiti Teknologi MARA, KampusTapah, 35400 Tapah Road, Tapah, Perak (Malaysia); Yahya, Muhd Zu Azhan [Faculty of Defence Sciences and Technology, Universiti Pertahanan Nasional Malaysia, Kem Sungai Besi, 57000 Kuala Lumpur (Malaysia); Ali, Ab Malik Marwan [Institute of Science, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia)

    2015-08-28

    Epoxidized 30% poly(methyl methacrylate)-grafted natural rubber (EMG 30) as a polymer host in solid polymer electrolytes (SPEs) has been investigated. EMG30 was synthesized via performicepoxidation method onto 30% poly(methyl methacrylate)-grafted natural rubber (MG30) and the formations of epoxy group were discussed. The EMG30 were characterized by proton nuclear magnetic resonance ({sup 1}HNMR) to investigate their chemical structure and differential scanning calorimeter to determine their crystallinity. A new peak in {sup 1}HNMR spectra (2.71 ppm) confirmed the appearance of epoxy group. SPE based on EMG30 doped with 40 wt% LiCF{sub 3}SO{sub 3} show the highest conductivity. The complexation between EMG30 and LiCF{sub 3}SO{sub 3} were confirmed by attenuated total reflection Fourier transform infrared (ATR-FTIR)

  3. Effect of epoxidation on 30% poly(methyl methacrylate)-grafted natural rubber polymer electrolytes

    International Nuclear Information System (INIS)

    Nazir, Khuzaimah; Aziz, Ahmad Fairoz; Adam, Nurul Ilham; Yahya, Muhd Zu Azhan; Ali, Ab Malik Marwan

    2015-01-01

    Epoxidized 30% poly(methyl methacrylate)-grafted natural rubber (EMG 30) as a polymer host in solid polymer electrolytes (SPEs) has been investigated. EMG30 was synthesized via performicepoxidation method onto 30% poly(methyl methacrylate)-grafted natural rubber (MG30) and the formations of epoxy group were discussed. The EMG30 were characterized by proton nuclear magnetic resonance ( 1 HNMR) to investigate their chemical structure and differential scanning calorimeter to determine their crystallinity. A new peak in 1 HNMR spectra (2.71 ppm) confirmed the appearance of epoxy group. SPE based on EMG30 doped with 40 wt% LiCF 3 SO 3 show the highest conductivity. The complexation between EMG30 and LiCF 3 SO 3 were confirmed by attenuated total reflection Fourier transform infrared (ATR-FTIR)

  4. Effect of epoxidation on 30% poly(methyl methacrylate)-grafted natural rubber polymer electrolytes

    Science.gov (United States)

    Nazir, Khuzaimah; Aziz, Ahmad Fairoz; Adam, Nurul Ilham; Yahya, Muhd Zu Azhan; Ali, Ab Malik Marwan

    2015-08-01

    Epoxidized 30% poly(methyl methacrylate)-grafted natural rubber (EMG 30) as a polymer host in solid polymer electrolytes (SPEs) has been investigated. EMG30 was synthesized via performicepoxidation method onto 30% poly(methyl methacrylate)-grafted natural rubber (MG30) and the formations of epoxy group were discussed. The EMG30 were characterized by proton nuclear magnetic resonance (1HNMR) to investigate their chemical structure and differential scanning calorimeter to determine their crystallinity. A new peak in 1HNMR spectra (2.71 ppm) confirmed the appearance of epoxy group. SPE based on EMG30 doped with 40 wt% LiCF3SO3 show the highest conductivity. The complexation between EMG30 and LiCF3SO3 were confirmed by attenuated total reflection Fourier transform infrared (ATR-FTIR).

  5. Effects of radio sensitizers in the vulcanization of natural rubber latex induced by gamma radiation

    International Nuclear Information System (INIS)

    Souza, A. de; Canavel, V.; Araujo, S.C. de; Guedes, S.M.L.

    1992-01-01

    The effect of C Cl 4 and n-butyl acrylate as a sensitizer for radiation vulcanization of 60% DRC natural rubber latex with gamma rays, was studied relating tensile strength of vulcanized latex. The vulcanization dose is 200 kGy for natural rubber latex and it decreases to 40 kGy and to 9 kGy in the presence of C Cl 4 / potassium laureate and n-butyl acrylate / t-butyl hydroperoxide, respectively. The H 2 O 2 as a co-sensitizer does not change the efficiency of the combination of these sensitizers. The IV spectra show the formation of C=O after the irradiation as consequence of oxidation reactions. (author)

  6. Epoxidized Natural Rubber/Chitosan Network Binder for Silicon Anode in Lithium-Ion Battery.

    Science.gov (United States)

    Lee, Sang Ha; Lee, Jeong Hun; Nam, Dong Ho; Cho, Misuk; Kim, Jaehoon; Chanthad, Chalathorn; Lee, Youngkwan

    2018-05-16

    Polymeric binder is extremely important for Si-based anode in lithium-ion batteries due to large volume variation during charging/discharging process. Here, natural rubber-incorporated chitosan networks were designed as a binder material to obtain both adhesion and elasticity. Chitosan could strongly anchor Si particles through hydrogen bonding, while the natural rubber could stretch reversibly during the volume variation of Si particles, resulting in high cyclic performance. The prepared electrode exhibited the specific capacities of 1350 mAh/g after 1600 cycles at the current density of 8 A/g and 2310 mAh/g after 500 cycles at the current density of 1 A/g. Furthermore, the cycle test with limiting lithiation capacity was conducted to study the optimal binder properties at varying degree of the volume expansion of silicon, and it was found that the elastic property of binder material was strongly required when the large volume expansion of Si occurred.

  7. Physical-biopolymer characterization of polyhydroxybutyrate-co-hydroxyvalerate (PHBV) blended with natural rubber latex

    Energy Technology Data Exchange (ETDEWEB)

    Kuntanoo, K., E-mail: thip-kk@hotmail.com [Graduate School of Khon Kaen University, Khon Kaen, 40002 Thailand (Thailand); Promkotra, S., E-mail: sarunya@kku.ac.th [Department of Geotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen 40002 Thailand (Thailand); Kaewkannetra, P., E-mail: paknar@kku.ac.th [Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen 40002 Thailand (Thailand)

    2015-03-30

    A biopolymer of polyhydroxybutyrate-co-hydroxyvalerate (PHBV) is blended with bio-based materials, natural rubber latex, to improve their microstructures. The various ratios between PHBV and natural rubber latex are examined to develop their mechanical properties. In general, physical properties of PHBV are hard, brittle and low flexible while natural rubber (NR) is presented itself as high elastic materials. Concentrations of the PHBV solution are constituted at 1%, 2% and 3% (w/v). The mixtures of their PHBV solutions to natural rubber latex are produced the blended films in three different ratios of 4:6, 5:5 and 6:4, respectively. They are characterized by appearance analyses which are the scanning electron microscope (SEM), universal testing machine (UTM) and differential scanning calorimetry (DSC). The SEM photomicrographs of the blended films and the controlled PHBV can provide the void distribution in the range of 12-14% and 19-21%, respectively. For mechanical properties of the blended films, the various elastic moduli of 1%, 2% and 3% (w/v) PHBV are the average of 773, 956 and 1,007 kPa, respectively. The tensile strengths of the blends increase with the increased concentrations of PHBV, similarly trend to the elastic modulus. The crystallization and melting behavior of unmixed PHBV and the blends are determined by DSC. Melting transition temperatures (T{sub m}) of the unmixed PHBV are stated two melting peak at 154°C and 173°C. Besides, the melting peaks of the blends alter in the range of 152-156°C and 168-171°C, respectively. According to morphology of the blends, the void distribution decreases twice compared to the unmixed PHBV. The results of mechanical properties and thermal analysis indicate that the blended PHBV can be developed their properties by more resilient and wide range of temperature than usual.

  8. Test trial radiation vulcanization of natural rubber latex in Jakarta Indonesia

    International Nuclear Information System (INIS)

    Devendra, R.; Kulatunge, S.S.; Chandralal, H.N.K.K.; Kalyani, N.M.V.; Seneviratne, J.; Wellage, S.

    1994-01-01

    Radiation vulcanization of natural rubber latex (RVNRL) can be used to make large quantities of specially stabilized latex. It is possible to obtain RVNRL films of tensile strength over 25 MPa. The films could be either coagulant dipped or cast. It is very important to determine the correct radiation dose which gives the maximum tensile strength. Cross linking density or prevulcanized relax modulus (PRM) at 100% is a reliable property to control the prevulcanization

  9. Numerical analysis of some problems related to the mechanics of pneumatic tires: Finite deformation/rolling contact of a viscoelastic cylinder and finite deformation of cord-reinforced rubber composites

    Science.gov (United States)

    Oden, J. T.; Becker, E. B.; Lin, T. L.; Hsieh, K. T.

    1984-01-01

    The formulation and numerical analysis of several problems related to the behavior of pneumatic tires are considered. These problems include the general rolling contact problem of a rubber-like viscoelastic cylinder undergoing finite deformations and the finite deformation of cord-reinforced rubber composites. New finite element models are developed for these problems. Numerical results obtained for several representative cases are presented.

  10. Electrical conductivity of short carbon fibers and carbon black-reinforced chloroprene rubber

    International Nuclear Information System (INIS)

    Khoshniat, A. R.; MirAli, M.; Hemmati, M.; Afshar Taromi, F.; Katbab, A.

    2002-01-01

    Elastomers and plastics are intrinsically insulating materials, but by addition of some conductive particles such as conductive carbon black, carbon fibers and metals, they can change to conductive form. Conductivity of these composites are due to formation of the lattices of conductive filler particles in polymer chains. In this report, conductivity of chloroprene rubber filled with carbon black and carbon fibers as a function of temperature and pressure are studied. Electrical conductivity of chloroprene in a function of temperature and pressure are studied. Electrical conductivity of chloroprene in the presence of carbon black with proper mixing conditions increases to the conductivity level of semiconductors and even in the presence of carbon fibers it increases to the level of a conductor material. Meanwhile, the sensitivity of this compound to heat and pressure rises. Thus these composites have found various applications in the manufacture of heat and pressure sensitive sensors

  11. Graft Copolymerization of Methyl Methacrylate Monomer onto Starch and Natural Rubber Latex Initiated by Gamma Irradiation

    Directory of Open Access Journals (Sweden)

    S. Iskandar

    2011-04-01

    Full Text Available To obtain the degradable plastic, the graft copolymerization of methyl methacrylate onto starch and natural rubber latex was conducted by a simultaneous irradiation technique. Gamma-ray from cobalt-60 source was used as the initiator. The grafted copolymer of starch-polymethyl methacrylate and the grafted copolymer of natural rubber-polymethyl methacrylate were mixed in the blender, and dried it in the oven. The dried grafted copolymer mixture was then molded using hydraulic press machine. The effect of irradiation dose, composition of the grafted copolymer mixture, film forming condition and recycle effect was evaluated. The parameters observed were tensile strength, gel fraction and soil burial degradability of grafted copolymer mixture. It was found that the tensile strength of grafted copolymer mixture increased by -ray irradiation. Increasing of the grafted copolymer of natural rubber-polymethyl methacrylate content, the gel fraction and tensile strength of the grafted copolymer mixture increased. The tensile strength of the grafted copolymer mixture was increased from 18 MPa to 23 MPa after recycled (film forming reprocessed 3 times. The grafted copolymer mixture was degraded completely after soil buried for 6 months

  12. Safety Evaluation Test on Human for Radiation Pre vulcanised Natural Rubber Latex (RVNRL)

    International Nuclear Information System (INIS)

    Pairu Ibrahim; Wan Manshol Wan Zain; Chai, Chee Keong; Sofian Ibrahim; Saadiah Sulaiman; Sharifah Ismail

    2010-01-01

    This paper discussed about clinical test conducted to determine safety evaluations on human for latex examination gloves and latex films made from Radiation Vulcanized Natural Rubber Latex (RVNRL). Two types of test were being adopted which are i) Modified Draize-95 test and ii) Patch Test on Sensitized Individuals. Modified Draize-95 test was conducted on 200 non-sensitized human subjects and Patch Test on Sensitized Individuals was conducted on 25 individuals who are allergic to the defined major chemical sensitizer presents in natural rubber product. It was found that Modified Draize-95 test has prove that there is no clinical evidence on the presence of residual chemical additives at the level that may induce Type IV allergy in the un sensitized general user population in the RVNRL gloves. Meanwhile Patch Test on Sensitized Individuals has proved that the patch test conducted using the test article on 25 individuals who are allergic to the defined major chemical sensitizers present in natural rubber products, thiuram, carbamates or thiazoles produced a negative response, meeting the pre requirement for the claim of reduced reaction-inducing potential. (author)

  13. Development of a BR-UASB-DHS system for natural rubber processing wastewater treatment.

    Science.gov (United States)

    Watari, Takahiro; Thanh, Nguyen Thi; Tsuruoka, Natsumi; Tanikawa, Daisuke; Kuroda, Kyohei; Huong, Nguyen Lan; Tan, Nguyen Minh; Hai, Huynh Trung; Hatamoto, Masashi; Syutsubo, Kazuaki; Fukuda, Masao; Yamaguchi, Takashi

    2015-11-21

    Natural rubber processing wastewater contains high concentrations of organic compounds, nitrogen, and other contaminants. In this study, a treatment system composed of a baffled reactor (BR), an upflow anaerobic sludge blanket (UASB) reactor, and a downflow hanging sponge (DHS) reactor was used to treat natural rubber processing wastewater in Vietnam. The BR showed good total suspended solids removal of 47.6%, as well as acidification of wastewater. The UASB reactor achieved a high chemical oxygen demand (COD) removal efficiency of 92.7% ± 2.3% and energy recovery in the form of methane with an organic loading rate of 12.2 ± 6.6 kg-COD·m -3 ·day -1 . The DHS reactor showed a high performance in residual organic matter removal from UASB effluent. In total, the system achieved high-level total COD removal of 98.6% ± 1.2% and total suspended solids removal of 98.0% ± 1.4%. Massive parallel 16S rRNA gene sequencing of the retained sludge in the UASB reactor showed the predominant microbial phyla to be Bacteroidetes, Firmicutes, Proteobacteria, WWE1, and Euryarchaeota. Uncultured bacteria belonging to the phylum Bacteroidetes and Phylum WWE1 were predominant in the UASB reactor. This microbial assemblage utilizes the organic compounds contained in natural rubber processing wastewater. In addition, the methane-producing archaea Methanosaeta sp. and Methanolinea sp. were detected.

  14. Thermal, mechanical, and moisture absorption properties of egg white protein bioplastics with natural rubber and glycerol.

    Science.gov (United States)

    Jones, Alexander; Zeller, Mark Ashton; Sharma, Suraj

    2013-07-03

    Petroleum-based plastics have many drawbacks: the large amount of energy required to produce the plastic, the waste generated as a result of plastic production, and the accumulation of waste due to slow degradation rate. It is because of these negative attributes of conventional plastic use that attention is being focused on environmentally friendly plastics from alternative sources. Albumin protein provides one possible source of raw material, with inherent antimicrobial properties that may make it suitable for medical applications. We conducted this study to investigate the various bioplastic properties of the albumin with the use of three plasticizers - water, glycerol, and natural rubber latex. Based on results, 75:25 albumin-water, 75:25 albumin-glycerol, and 80:20 albumin-natural rubber were the best blending ratios for each plasticizer for a subsequent time study to determine water stability, with the 80:20 albumin-natural rubber blend ratio having possessed the best thermal, tensile, and viscoelastic properties overall.

  15. Prevalence of Allergy to Natural Rubber Latex and Potential Cross Reacting Food in Operation Room Staff in Shiraz Hospitals -2006

    OpenAIRE

    H Nabavizade; R Amin

    2007-01-01

    Introduction & Objective: Allergic reactions to natural rubber latex have increased during past 10 years especially among health care workers and patients with high exposure to latex allergens. Allergic reaction to latex is related to many diseases like occupational asthma. This study was performed to determine the prevalence of allergy to natural rubber latex and potential cross reacting food in operation room staff in Shiraz hospitals. Materials & Methods: In this cross-sectional descr...

  16. Study of tribological properties of natural rubber containing carbon nanotubes and carbon black as hybrid fillers

    Science.gov (United States)

    Harea, Evghenii; Stoček, Radek; Storozhuk, Liudmyla; Sementsov, Yurii; Kartel, Nikolai

    2018-04-01

    Dry friction and wear properties of natural rubber (NR), containing multi-walled carbon nanotubes (MWCNT) and carbon black (CB), were investigated. Natural rubber (NR)-based composites containing all common additives and curatives, and a fixed amount (30 phr—parts per 100 rubber by weight) of hybrid fillers (MWCNT x + CB30-x ) were prepared by simple mixing procedure and tested. The main goal was to study the behaviours of composites at different tribological testing conditions, such as friction speed and normal load. It was found that with an increase of concentration of MWCNT from x = 0 phr to x = 5 phr in studied composites, there was a decrease in the coefficient of friction (COF) with no significant change in wear in the framework of each used combination of testing parameters. Generally, higher friction speed at certain normal force led to the increase of COF of all the samples and wear reflected deliberate value fluctuation. Also, it was established that considerable growth of wear and unexpected reducing of friction coefficient ensued from increasing of applied load for every fixed sliding speed.

  17. Self-Healing Natural Rubber with Tailorable Mechanical Properties Based on Ionic Supramolecular Hybrid Network.

    Science.gov (United States)

    Xu, Chuanhui; Cao, Liming; Huang, Xunhui; Chen, Yukun; Lin, Baofeng; Fu, Lihua

    2017-08-30

    In most cases, the strength of self-healing supramolecular rubber based on noncovalent bonds is in the order of KPa, which is a challenge for their further applications. Incorporation of conventional fillers can effectively enhance the strength of rubbers, but usually accompanied by a sacrifice of self-healing capability due to that the filler system is independent of the reversible supramolecular network. In the present work, in situ reaction of methacrylic acid (MAA) and excess zinc oxide (ZnO) was realized in natural rubber (NR). Ionic cross-links in NR matrix were obtained by limiting the covalent cross-linking of NR molecules and allowing the in situ polymerization of MAA/ZnO. Because of the natural affinity between Zn 2+ ion-rich domains and ZnO, the residual nano ZnO participated in formation of a reversible ionic supramolecular hybrid network, thus having little obstructions on the reconstruction of ionic cross-links. Meanwhile, the well dispersed residual ZnO could tailor the mechanical properties of NR by changing the MAA/ZnO molar ratios. The present study thus provides a simple method to fabricate a new self-healing NR with tailorable mechanical properties that may have more potential applications.

  18. Exploration of Barriers in Achieving Proactive Environmental Strategies in a Natural Rubber Industry : A Case Study

    Directory of Open Access Journals (Sweden)

    Syarifa Arum Kusumastuti

    2016-05-01

    Full Text Available As the evolving of environmental issues over time, the development of environmental management approaches in industries began to shift to the prevention of pollution to reduce environmental impact. However, in practice, many obstacles encountered during the environmental management change to be more proactive. This study aims to explore the barriers of achieving the proactive environmental strategy in a rubber processing industry. Used a case study approach in a natural rubber processing factory, the data was collected through interviews with experts and sources as well as observation in the field. This study shows main barriers that faced by the company consist of financial issue, human resources, communities’ pressure, technological change and communication with environmental experts. The results of this study suggest conducting cooperation with research institutions or environmental experts especially for skills that cannot be controlled by the manager or employees in the company. 

  19. Extractable proteins from electron beam (EB) irradiated natural rubber (NR) latex

    International Nuclear Information System (INIS)

    Feroza Akhtar; Fumio Yoshii; Keizo Makuuchi

    1996-01-01

    The protein assay of natural rubber latex (NRL) vulcanized by low energy electron beam (EB, 300 keV, 30 mA) has been carried out using Bicinchoninic acid (BCA) reagent. Extractable protein in irradiated latex film was determined by measuring the absorption of colored solution at 562 nm using UV spectrometer. The effect of various radiation doses on the extractable protein content of NRL was investigated. It was ,found that the quantities of extractable protein increases with radiation dose. When compared with ,gamma-ray irradiated samples the same trend was observed. Electron beam irradiated latex films are leached in 1% (ammonia water for various lengths of time. From the results it was established that within 2 hours of leaching in ammonia water most of the extractable protein (96%) were removed from rubber film

  20. Extraction and comparison of proteins from natural rubber latex by conventional and ionizing radiation methods

    International Nuclear Information System (INIS)

    Rogero, Sizue O.; Spencer, Patrick J.; Campos, Vania E.; Lusvarghi, Fabio M.; Higa, Olga Z.

    1997-01-01

    Several proteins in natural rubber latex (NRL) have been assigned to be significant allergens. It is known that proteins submitted to ionizing radiation suffer denaturation and immunochemical modification resulting in low antigenic reactivity. The aim of this study was to extract and compare water extractable proteins from NRL films vulcanized by conventional and by ionizing radiation methods. SDS-polyacrylamide gel electrophoresis (SDS--PAGE) and high pressure liquid chromatography (HPLC) showed a diffuse protein band of about 14 KDa, which we believe is rubber elongation factor (REF), in both eluates, but smaller in latex film vulcanized by ionizing radiation. REF has been suggested to be a major latex allergen. These data suggest that ionizing radiation vulcanization could be an useful method for the production of NRL goods with low antigenicity. (author). 8 refs., 2 figs., 1 tab

  1. The Effect of Paraffin Wax to Properties of Radiation Vulcanization Natural Rubber Latex (RVNRL)

    International Nuclear Information System (INIS)

    Mohd Noorwadi Mat Lazim; Sofian Ibrahim; Muhammad Saiful Omar

    2015-01-01

    Dipping factories often encounter a serious problem with high tackiness of the finish products during storage. The tackiness effect can be lead to rejection of products. This tackiness effect of natural (NR) rubber film originates in the free rubber chain ends at the surface of the film. The tackiness is not depends on the degree of crosslinking (vulcanization), since radiation itself unable to reduce the tackiness effect. The RVNRL requires addition of additive or anti-tack agent into formulation to reduce tackiness effect. In this experiment, paraffin wax manufactured by Emulco Sdn Bhd under the trade name Aquawax 48 was added into RVNRL formulation as anti-tack and the effect of paraffin wax to physical and mechanical properties of RVNRL was study. (author)

  2. Radiation vulcanization of natural rubber latex using irradiation n-butyl acrylate aqueous emulsion as sensitizer

    International Nuclear Information System (INIS)

    Vo Van Thien; Nguyen Quoc Hien; Keizo Makuuchi; Fumio Yoshii

    2000-01-01

    Natural rubber latex was vulcanized by gamma radiation with n-butyl acrylate aqueous emulsion irradiated at dose of 1.5 kGy as sensitizer. The total solid content of latex increases on the irradiation dose. The viscosity of latex on the standing time was investigated and became stable after one month of storage. The gel content of latex films increasing with irradiation dose and attained more than 94% at dose of 10 kGy. Tensile strength of films reached the values of 31MPa; 30 Mpa and 25 Mpa at vulcanization doses of 20 kGy, 15 kGy and 8 kGy for the concentrations of sensitizer 7 phr, 9 phr and 13 phr respectively. Elongation at break decreases as increasing dose. Tear strength of rubber films was from 30-40 N/mm. The tackiness of latex films decreases and smell of vulcanized latex is almost negligible. (author)

  3. Effect of moisture on natural fibre reinforced plastics | Ogakwu | West ...

    African Journals Online (AJOL)

    In this research, the rate of moisture absorption of the composites reinforced with natural fibres – Ukam plant fibres (chochlostermum placoni) were studied and determined.Composite cubes and plates of different sizes were prepared, then immersed in water for 24 hours at room temperature in order to determine the extent ...

  4. Compósitos de borracha natural com polianilina Composites of natural rubber with polyaniline

    Directory of Open Access Journals (Sweden)

    Patrini D. Galiani

    2007-06-01

    Full Text Available Compósitos de borracha natural (Hevea brasiliensis-BN/polianilina - PANI, com diferentes composições foram obtidos através da polimerização por emulsão do monômero anilina na presença da BN e do ácido dodecilbenzeno sulfônico (DBSA. Filmes finos e homogêneos foram obtidos por prensagem a quente. Os compósitos foram caracterizados por condutividade elétrica, FTIR, UV-vis-NIR, DSC e difração de raios X. Compósito com condutividade elétrica cerca de 14 ordens de grandeza maior que a BN foi obtido. Este alto valor de condutividade é atribuído à formação da PANI no estado dopado no compósito, que foi verificado através das técnicas de UV-vis-NIR e FTIR. Os resultados obtidos com a técnica de DSC e difratometria de raios X indicaram que os polímeros são imiscíveis e que a presença da borracha não altera significantemente a fase cristalina da PANI-DBSA no compósito.In this work composites with different compositions were obtained from natural rubber (Hevea brasiliensis (NR and polyaniline (PANI using the emulsion polymerization of aniline in the presence of NR and dodecylbenzenesulfonic acid (DBSA. The samples in film form were obtained by pressing the precipitate at 100 °C for 5 minutes. The composites were characterized by electrical conductivity, Fourier-transform infrared spectroscopy (FTIR, UV-vis-NIR spectroscopy, differential scanning calorimetry (DSC and X ray diffraction. Composites with electrical conductivity about 14 orders of magnitude higher than NR were obtained. The UV-vis-NIR and FTIR spectra showed that PANI-DBSA was formed in the composites, thus making it responsible for their high conductivity. The DSC thermograms indicated that the two polymers are immiscible and X ray diffraction evidenced that NB does not considerably affect PANI-DBSA crystalline phase in the composite.

  5. Development of an efficient process for radiation vulcanization of natural rubber latex using hydroperoxide with sensitizer

    International Nuclear Information System (INIS)

    Siri-upathum, C.; Sonsuk, M.

    1996-01-01

    An attempt was made to reduce irradiation dose for radiation vulcanization of natural rubber latex. A promising method was to partially crosslink the latex by radiation vulcanization using n-butyl acrylate (n-BA) as sensitizer and t-butyl hydroperoxide (BHPO) as a co-sensitizer followed by redox vulcanization using residual BHPO as an oxidant and either fructose or tetra ethylene penta mine as reducing agents. It was found that the irradiation dose was reduced to 4 kGy with 5 phr n-BA as sensitizer and 0.1 phr BHPO as co-sensitizer. Successive crosslinking to full vulcanization was done by redox vulcanization using either 4 phr fructose at 60 degree C for 3 hours of 0.4 phr tetra-ethylene penta mine at room temperature for 1 hour. The rubber films obtained had tensile strength of about 25 MPa, modulus 300% of 0.9 MPa and crosslink density of about 1.5 x 10 19 crosslink/cm 3 . It was noted that the rubber film from the co-vulcanization was the average value of the values obtained by radiation vulcanization and redox vulcanization

  6. Use of a modified natural-rubber phantom for radiotherapy dosimetry measurements

    International Nuclear Information System (INIS)

    Bradley, D.A.; Ng, K.-H.; Aziz, Y.B.

    1988-01-01

    The utility of a phantom material, based on SMR(L) [Standard Malaysian Rubber] grade natural rubber and a formulation used for the proprietary rubber phantom-material, Temex, has been examined for the 1-MeV photon-energy range using γ radiation from a 60 Co source. Measurement has also been performed with 60-keV photons using the radionuclide 241 Am. At photon-therapy energy levels the measured response, when compared with tabulated central-axis percentage depth doses for defined measuring conditions, produces everywhere (in the range 1-19 cm depth) better than 2% deviation. The favourable measured response characteristics combined with the ease of processing and casting the phantom material provide the basis for useful radiotherapy machine calibration and anthropomorphic dosimetry measurements. The measured mass-attenuation coefficient, at 60 keV, of 0.204 cm 2 g -1 (± 3%) is in close agreement with tabulated values for water (0.2055 cm 2 g -1 ). (author)

  7. Investigations on the properties of NH4HCO3 filled natural rubber based magnetorheological elastomers (MREs)

    Science.gov (United States)

    Fan, Lili; Wang, Guoping; Wang, Wenju; Shi, Guanxin; Yang, Fufeng; Rui, Xiaoting

    2018-04-01

    Various anisotropic magnetorheological elastomers (MREs) were synthesized using the rubber mixing technique. Magnetic and temperature distributions of the experimental equipment and test instruments were analyzed by the ANSYS. NH4HCO3 was filled in the natural rubber matrix to modify properties of MREs. Microstructures and compositions of samples were studied by the scanning electron microscope (SEM), the energy dispersive x-ray spectroscopy (EDAX) analysis and x-ray powder diffraction (XRD). Via vibrating sample magnetometer (VSM) and density functional theory (DFT) method, the magnetic property of carbonyl iron (CI) was illuminated. The shear storage modulus and MR effect of MREs were investigated by the dynamic mechanical analyzer (DMA). It indicated that distributions of magnetic and temperature in the experimental and testing devices were uniform. Before vulcanization, CI particles were uniformly distributed in the matrix, while a CI chain structure was formed and embedded in the matrix after the vulcanization process. Moderate addition of NH4HCO3 accelerated the rubber vulcanization and enhanced the MR effect.

  8. Effect of fibre treatments on tensile properties of ethylene vinyl acetate/natural rubber/mengkuang leaf fibre (EVA/NR/MLF) thermoplastic elastomer composites

    Science.gov (United States)

    Hashim, Faiezah; Ismail, Hanafi; Rusli, Arjulizan

    2017-07-01

    Nowadays, a great attention has been dedicated to natural fibers as reinforcement for polymer composites. Natural fibers, compared to glass fibers, exhibit better mechanical properties, such as stiffness, impact strength, flexibility and modulus. However, certain drawbacks, such as the incompatibility between fibers and polymer matrices, the tendency to form aggregates during processing and the poor resistance to moisture, reduce the use of these natural fibers as reinforcements in polymers. Several treatments and modifications are being used to improve the adhesion between fibre and matrix. In this work, the effect of bleaching treatments using hydrogen peroxide in the Mengkuang leaf fibre (MLF) was evaluated on tensile properties of Ethylene Vinyl Acetate (EVA)/Natural Rubber (NR)/MLF composites. Treated MLF were mixed with the EVA/NR blend in Haake internal mixer at 120 °C and rotor speed of 50 rpm for 10 minutes. Fibre morphology and the fibre/matrix interface ware further characterized by scanning electron microscopy (SEM). The tensile strength was increased by about 8% as compared to the composites with untreated fibers. The increased adhesion between fiber and matrix was also observed by SEM. Thus, EVA/NR/MLF composites reinforced with the treated fibres exhibited better tensile properties than untreated EVA/NR/MLF composites.

  9. Energy Absorption Capacity in Natural Fiber Reinforcement Composites Structures

    Directory of Open Access Journals (Sweden)

    Elías López-Alba

    2018-03-01

    Full Text Available The study of natural fiber reinforcement composite structures has focused the attention of the automobile industry due to the new regulation in relation to the recyclability and the reusability of the materials preserving and/or improving the mechanical characteristics. The influence of different parameters on the material behavior of natural fiber reinforced plastic structures has been investigated, showing the potential for transport application in energy absorbing structures. Two different woven fabrics (twill and hopsack made of flax fibers as well as a non-woven mat made of a mixture of hemp and kenaf fibers were employed as reinforcing materials. These reinforcing textiles were impregnated with both HD-PE (high-density polyethylen and PLA (polylactic acid matrix, using a continuous compression molding press. The impregnated semi-finished laminates (so-called organic sheets were thermoformed in a second step to half-tubes that were assembled through vibration-welding process to cylindric crash absorbers. The specimens were loaded by compression to determine the specific energy absorption capacity. Quasi-static test results were compared to dynamic test data obtained on a catapult arrangement. The differences on the specific energies absorption (SEA as a function of different parameters, such as the wall thickness, the weave material type, the reinforced textiles, and the matrix used, depending on the velocity rate application were quantified. In the case of quasi-static analysis it is observed a 20% increment in the SEA value when wove Hopsack fabric reinforcement is employed. No velocity rate influence from the material was observed on the SEA evaluation at higher speeds used to perform the experiments. The influence of the weave configuration (Hopsack seems to be more stable against buckling effects at low loading rates with 10% higher SEA values. An increase of SEA level of up to 72% for PLA matrix was observed when compared with HD

  10. 2,2,2-Trifluoroethyl methacrylate-graft-natural rubber: Synthesis and application as compatibilizer in natural rubber/fluoroelastomer blends

    Energy Technology Data Exchange (ETDEWEB)

    Hinchiranan, N., E-mail: nhn78@hotmail.com [Department of Chemical Technology, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Wannako, P. [Program in Petrochemistry and Polymer Science, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Paosawatyanyong, B. [Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Prasassarakich, P. [Department of Chemical Technology, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand)

    2013-05-15

    The incompatibility and immiscibility of natural rubber (NR)/fluoroelastomers (FKM) blends were improved by incorporation of a graft copolymer synthesized from the free radical graft copolymerization of 2,2,2-trifluoroethyl methacrylate (TFEM) onto NR initiated by benzoyl peroxide via a melt-mixing process. The grafting properties were investigated as functions of the initiator and monomer concentrations, reaction temperature and time. At the optimal conditions, the obtained graft NR (GNR) purified by Soxhlet extraction contained a maximum grafting efficiency of 1.34% with 49.1% monomer conversion. The structure of the purified GNR was analyzed using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and nuclear magnetic resonance spectroscopy ({sup 1}H NMR and {sup 19}F NMR). The gross GNR was then applied as the compatibilizer for NR/FKM vulcanizates (20/80 (w/w)) cured by peroxide vulcanization. The addition of GNR at 15 parts per hundred of rubber (phr) gave a vulcanizate with the highest tensile strength (9.93 MPa), some 5.31-fold higher than that of the incompatibilized one (1.87 MPa). This is likely to be due to the higher degree of homogeneity of the constituent phases in the GNR-compatibilized blends, as observed by scanning electron microscopy (SEM). The GNR-compatibilized NR/FKM vulcanizates were also resistant to gasohol E85 (85% (w/w) of ethanol). Highlights: ► 2,2,2-Trifluoroethyl methacrylate could be grafted on NR via melt-mixing process. ► Effect of grafting parameters on grafting efficiency and gel content was observed. ► NR/FKM containing graft NR had higher tensile strength than uncompatibilized ones. ► The compatibilized NR/FKM vulcanizates had higher gasohol-swelling resistance.

  11. Study on grafting of monomer onto natural rubber latex by radiation technique

    International Nuclear Information System (INIS)

    Nguyen Tan Man; Le Hai; Tran Thi Tam; Le Huu Tu, Pham Thi Sam; Dao Minh Phuong; Ha Thuc Huy

    2004-01-01

    Radiation vulcanization of natural rubber latex has been extensively developed through programmers assisted by the IAEA and UNDP under RCA in Asia and Pacific Region. R-D has been done in most of the Member States with technical assistance from Japan's Takasaki Radiation Chemistry Establishment. Radiation vulcanized natural rubber latex (RVNRL) has many advantages over the conventional sulfur vulcanized latex, such as absence of nitrosamine and low cytotoxicity. Radiation crosslinking is a room temperature process, itself an important cost advantage, it is easily controlled and desired extend of crosslinking is easily achieved by controlling the dose (irradiation time). Disadvantages of RVNRL to be improved are poor physical properties of film such as low tensile strength and tear strength. The research groups of Japan, Thailand and Indonesia concentrated on the improvement of physical properties of RVNRL using radiation grafted PMMA as additive [2]. F. Sundardi and W. Sofiarti have reported that tensile strength and hardness increased by radiation grafting of styrene onto NR [5]. Ono et al have reported the grafting of MMA onto NR by gamma irradiation at a dose of 5 kGy for producing thermoplastic elastomers [4]. The objective of this project is to report the results of studies of radiation graft-copolymerization of methyl methacrylate (MMA) or styrene (St) onto natural rubber latex in order to improve their physico-mechanical properties and evaluation of grafted material using Small-Angle Neutron Scattering through FNCA Project. The grafting degree of MMA and St onto NR increased with the increase of irradiation dose and monomer concentration. The alteration of grafted products structure was determined by IR method. Tensile strength, Shore A hardness, 100% modulus of grafted products increased with the increase of monomer concentration and irradiation dose while elongation at break decreased. The grafted products were characterized by Transmission Electron

  12. Radiation induced grafting of monomers onto natural rubber : processes and applications

    International Nuclear Information System (INIS)

    Sunny Sebastian, M.

    2001-01-01

    Full text: Certain inherent mechanical properties of natural rubber (NR) can be modified by grafting vinyl monomers onto the polymer backbone. This paper described the gamma radiation induced graft copolymerization of methyl methacrylate (MMA), styrene and acrylonitrile (AN) onto NR. The graft copolymers can be crosslinked by sulphur and organic accelerators. The crosslinked graft copolymers show improved modulus and hardness in their films compared to NR. However the tensile strength of the films is reduced by grafting. The methods for preparing the graft copolymers, their properties and applications are briefly described

  13. The influence of radiolytic sensitizers in natural rubber latex vulcanization induced by ionizing radiation

    International Nuclear Information System (INIS)

    Guedes, S.M.L.; Souza, A. de

    1991-01-01

    This work made on radiation vulcanization of natural rubber latex process by gamma rays from 60 Co source and electron beam of 1.5 MeV, 25 m A by Dynamitron, instead of classic process using sulfur. The experiment was carried out to study the influence of sensitizers (C Cl 4 and n-butyl acrylate) and was reported the vulcanization dose for each sensitizers, related to maximum tensile strength. The results show the possibility to introduce the volatile sensitizer (n-butyl acrylate) instead of C Cl 4 (toxic) in industry applications. (author)

  14. Radiation vulcanization of natural rubber latex using 250 keV electron beam machine

    Energy Technology Data Exchange (ETDEWEB)

    Chirinos, H.; Yoshii, F.; Makuuchi, K.; Lugao, A. E-mail: ablugao@net.ipen.br

    2003-08-01

    The sensitized radiation vulcanization of natural rubber latex has been carried out with 250 keV electrons. Latex was irradiated over a range of the beam current from 5 to 20 mA in the presence of sensitizers like the n-butyl acrylate (n-BA). The vulcanization dose decreases with increasing beam current condition. The rate of vulcanization (R{sub vul}) depends on the beam current (I) as given by the equation R{sub vul}=kI{sup 0.6}.

  15. Trial Production of Surgical Gloves from Irradiated Natural Rubber Latex on Factory Scale

    Directory of Open Access Journals (Sweden)

    M. Utama

    2005-07-01

    Full Text Available Trial production of surgical gloves from irradiated natural rubber latex at the PT. Laxindo Utama Serang Banten glove factory has been carried out. The variation of heating temperature and leaching time during processing were evaluated. The physical and mechanical properties and the protein allergen respond of surgical gloves using ELISA method were measured. The results showed that the physical and mechanical of surgical gloves such as tensile strength, modulus, and elongation at break arefound to meet the requirements of the ISO or SNI standard for surgical gloves. While the allergic response through clinical tested latex-sensitive protein allergen known as ELISA test is found to be negative.

  16. Surgical gloves fabrication using natural rubber latex vulcanized with gamma radiation

    International Nuclear Information System (INIS)

    Collantes, Hugo David Chirinos.

    1995-01-01

    Surgical gloves were manufactured by immersion coagulant method from vulcanized natural rubber latex by gamma rays at dose of 10 kGy in the air, at room temperature, using the following sensitizer vulcanization An-B 3 phr/KOH 0.2 phr. The influence of the parameter in the thickness of the surgical gloves manufacture, studied through fractional factorial designs technic, can be resumed by empirical linear correlation: y = 0.213 + 0.025 [Ca Cl 2 ] + 0.019 t. (author). 49 refs., 13 figs., 31 tabs

  17. Radiation Vulcanization of Natural Rubber Latex (RVNRL): A Potential Material for Nuclear Power Plant Gloves

    International Nuclear Information System (INIS)

    Pairu Ibrahim; Wan Manshol Wan Zain; Keong, C.C.; Mohd Noorwadi Mat Lazim

    2011-01-01

    Radiation vulcanization of natural rubber latex has great potential for the production of nuclear power plant gloves due to its low ash and mineral content. And this is in-line with the role played by Malaysian Nuclear Agency as Technical Supporting Organization for Nuclear Power Program. This paper discussed the evaluation done to determine ash content in RVNRL and SVNRL films. Both samples were prepared using casting technique and the properties were compared. Films prepared from raw latex without any vulcanizing agent were regarded as a control. (author)

  18. Preparation and Properties of Biocomposite Based on Natural Rubber and Bagasse Nanocellulose

    Directory of Open Access Journals (Sweden)

    Jarnthong Methakarn

    2015-01-01

    Full Text Available Biocomposite based on natural rubber (NR and bagasse nanocellulose (BNC was prepared in latex state. The mechanical, morphological and thermal properties of NR/BNC biocomposite were investigated. It was found that the addition of 3 wt% of BNC in NR film caused significant increase in modulus at 100% and 300% elongations and improved thermal stability of NR/BNC biocomposite. However, the strength at break and elongation at break of the biocomposite were not enhanced correlating to the morphological result obtained from scanning electron microscope (SEM.

  19. Modification of Iraqi Asphalt 40/50 Properties Using Saw Dust (SD and Natural Rubber Latex

    Directory of Open Access Journals (Sweden)

    Rusul l M. Darwesh

    2018-04-01

    Full Text Available The aim of this research is to enhance the fundamental properties for asphalt binder as those spec-ifications relate to performance of asphalt mixtures. In this paper studied the effect of add (2, 4 % SD in different sizes and (3, 5 and 7% Natural rubber latex to the straight asphalt 40/50 produced from Al-Dura refinery at 160C, it was added each additive separately and then added together to asphalt in same temperature, then tested physically and mechanically according to the American Society for Testing and Materials (ASTM, the result showed largely improvement.

  20. Effect of Compatibilizer on the Dynamic Mechanical and Electrical Properties of Kaolin Clay Reinforced EPDM Rubber

    International Nuclear Information System (INIS)

    Sarkhel, G.; Manjhi, S.

    2013-01-01

    Industrial pollution issue and dark colour of carbon black, clay based non black filler are getting more importance for reinforcing elastomer. EPDM-Kaolin composites with various maleated EPDM concentration have been prepared by mixing on a two roll mill. The rheometry data showed the optimum cure time increases with increasing compatibilizer concentration without decreasing torque value indicating that acidic functional groups comes from compatibilizer could retard cure rate and increase the optimum cure time rather than change in the ultimate cure state. As the filler concentration increases, the edge to edge and face to edge interaction between filler and EPDM increases and the free volume between EPDM molecules is reduced, the storage modulus increases. Moreover, the dynamic mechanical analysis also showed the increase in glass transition temperature with increase in filler concentration due to the inter-tubular diffusion of EPDM inside the clay. It was also observed that with increasing filler concentration, the resistivity and dielectric strength decreases and moreover with increasing compatibilizer concentration the resistivity decreases due to better dispersion of filler helps to build conduction path. The morphological study also revealed that homogeneity of filler dispersion increases with increase in compatibilizer concentration. (author)

  1. Effects of partial replacement of silica with surface modified nanocrystalline cellulose on properties of natural rubber nanocomposites

    Directory of Open Access Journals (Sweden)

    Y. F. Luo

    2012-01-01

    Full Text Available Nanocrystalline cellulose was modified by 3-aminopropyl-triethoxysilane (KH550. The modified nanocrystalline cellulose (MNCC was further investigated to partially replace silica in natural rubber (NR composites via coagulation. NR/MNCC/silica and NR/nanocrystalline cellulose (NCC/silica nanocomposites were prepared. Through the comparison of vulcanization characteristics, processing properties of compounds and mechanical properties, compression fatigue properties, dynamic mechanical performance of NR/MNCC/silica and NR/NCC/silica nanocomposites, MNCC was proved to be more efficient than NCC. MNCC could activate the vulcanization process, suppress Payne effect, increase 300% modulus, tear strength and hardness, and reduce the heat build-up and compression set. Moreover, fine MNCC dispersion and strong interfacial interaction were achieved in NR/MNCC/silica nanocomposites. The observed reinforcement effects were evaluated based on the results of apparent crosslinking density (Vr, thermo-gravimetric (TG and scanning electron microscopic (SEM analyses of NR/MNCC/silica in comparison with NR/NCC/silica nanocomposites.

  2. Numerical investigation of porous materials composites reinforced with natural fibers

    Science.gov (United States)

    Chikhi, M.; Metidji, N.; Mokhtari, F.; Merzouk, N. k.

    2018-05-01

    The present article tends to predict the effective thermal properties of porous biocomposites materials. The composites matrix consists on porous materials namely gypsum and the reinforcement is a natural fiber as date palm fibers. The numerical study is done using Comsol software resolving the heat transfer equation. The results are fitted with theoretical model and experimental results. The results of this study indicate that the porosity has an effect on the Effective thermal conductivity biocompoites.

  3. Development of magnetorheological elastomers based on Deproteinised natural rubber as smart damping materials

    Science.gov (United States)

    Ismail, Nik Intan Nik; Kamaruddin, Shamsul

    2017-12-01

    Magnetorheological elastomers (MREs) are composite materials consist of micron-sized magnetizable particles carbonyl iron particles [CIPs]) embedded in a soft elastomer matrix. MRE technology offers variable stiffness and damping properties under the influence of a magnetic field. Herein, the feasibility of incorporating a new generation specialty rubber, Pureprena as a matrix for MREs was investigated. Pureprena or Deproteinised Natural Rubber (DPNR) is a specialty natural rubber that has good dynamic properties, particularly with respect to damping parameters. DPNR was compounded with 60 wt% of CIPs to fabricate MREs. The performance of the DPNR-based MRE was measured in terms of tensile strength, dynamic properties, and magnetorheological (MR) effect and compared with polyisoprene (IR)-based MRE with the same amount of CIPs. Dynamic Mechanical Analyzer (DMA) showed that the loss factor in the glass transition region of the DPNR-based MRE was higher than that of the IR-based MRE, indicating better damping properties. Further investigation was undertaken using a servo-hydraulic testing machine to characterise the effect of strain amplitude and frequency on the dynamic properties (e.g. damping coefficient) of MREs at zero magnetic fields. The results demonstrate that DPNR-based MREs possess a comparable damping coefficient to that of IR-based MREs. In addition, MR effect, which relates to the ratio between elastic modulus with applied magnetic field (on-state) to the same modulus without applied fields (off-state), was measured using a parallel plate rheometer. As a result, DPNR-based MREs have improved MR effect than that of IR-based MREs. Moreover, variable stiffness is obtained when the magnetic field was increased to 0.8T. Loss factor or tan δ of MREs was found to vary against different magnetic fields. Finally, MREs with varied stiffness and damping were found to have potential as active control devices for smart damping materials.

  4. Influence of the Surfactant Nature on the Occurrence of Self-Assembly between Rubber Particles and Thermally Reduced Graphite Oxide during the Preparation of Natural Rubber Nanocomposites

    Directory of Open Access Journals (Sweden)

    Héctor Aguilar-Bolados

    2015-01-01

    Full Text Available The natural rubber (NR latex consists of polymer particles charged negatively due to the adsorbed phospholipids and proteins molecules. The addition of stable aqueous suspension of thermally reduced graphite oxide (TRGO stabilized by ionic surfactants to NR latex can favor the occurrence of interaction between the stabilized TRGO and NR particles. Herein, the use of two surfactants of different nature, namely, sodium dodecyl sulfate (SDS and dodecyltrimethylammonium bromide (DTAB, for the preparation of (TRGO/NR nanocomposites, is reported. Zeta potential and particle size measurements indicated that the use of DTAB as cationic surfactant results in the flocculation of NR particles and promoted the formation of ion-pair interactions between TRGO and the proteins and/or phospholipids present on the NR surface. This indicates that the use of DTAB can promote a self-assembly phenomenon between TRGO with adsorbed DTAB molecules and NR particles. The occurrence of self-assembly phenomenon allows obtaining homogenous dispersion of TRGO particles in the polymer matrix. The TRGO/NR nanocomposites prepared by the use of DTAB exhibited superior mechanical properties and excellent electrical conductivities reaching values of stress at 500% strain of 3.02 MPa and 10−4 S/cm, respectively.

  5. Use of low energy accelerator for the radiation vulcanization of natural rubber latex and nitrile rubber. The battle for the sustainability and poverty alleviation

    International Nuclear Information System (INIS)

    Chirinos, Hugo D.; Lugao, Ademar B.

    2001-01-01

    The origin of the Hevea braziliensis tree was the Amazonian basin. The rubber expansion at the end of 19th century brought prosperity and determined the borders of Amazonian countries. In spite of that, the Brazilian government has failed in establishing a successful policy for improving the NR production in the jungle. This battle has been a continuous defeat against the environment as it was not possible to control the fungus Microcyclos ulei in its natural environment. The defeat was catastrophic for the population of Amazon region as they were not able to shift to other sustainable activity. As a consequence of the tack of economical options, the population had to explore all available natural resources. It has been also catastrophic for the Amazonian environment. Nevertheless, rubber plantations were successfully introduced in areas were Hevea braziliensis was not native, mainly in the southeast of Brazil. And recently, it was also introduced near marginal areas of the humid forest in the Amazon due to the absence of the fungus Microcyclos ulei. Both, extraction of wild rubber and plantation have a key role in the maintenance of the forest health as the seringueiros not only have a sustainable activity but can also play a role as soldiers of the jungle. Actually, rubber activities are not only associated to the environment but also with poverty because the activities are labor intensive, so it needs cheap labor. The poverty is unfortunately spread out in rural areas of Brazil and in the peripheral areas of the big cities. Regarding environment and poverty the dilemma is critical in the Amazonian region and is the following: the forest should be maintained healthy and protected from devastating projects and at the same time needs of the inhabitants should be considered. (author)

  6. Oxidation Degradation Study And Use Of Phenol And Amina Antioxidant Compounds In Natural Rubber Cyclical

    Directory of Open Access Journals (Sweden)

    Arofah Megasari Siregar

    2015-08-01

    Full Text Available The research was conducted research into the use of commercial antioxidants Irganox 1010 wingstay to inhibit the oxidative degradation of cyclic polymers of natural rubber and polypropylene nanocomposite with commercial montmorillonite PP MMT-Clay. Proces mixing nanocomposit PPMMT using commercial compatibiliser PP-g-MA PB3200 made in an internal mixer at a temperature of 180 C for 10 minutes and 65 rpm rotor speed. Hyndered phenol antioxidant effectiveness was analyzed using Fourier Transform Infra Red FTIR. Analysis of infrared is done by measuring the broad index absorption of the carbonyl group CO at a wavelength of 1700 cm-1 and a broad index uptake hydroxyl group at a wavelength of 3400 cm-1 before and after heated in an oven temperature of 125oC with variations in exposure time. The results indicate the use of antioxidant Irganox 1010 in nanocomposite PP MMT with a stabilizing factor of 5.5. Further commercial antioxidants will be used to restrain the rate of oxidation degradation of the natural rubber products cyclical CNR.

  7. Lead zirconate (PbZrO3 embedded in natural rubber as electroactive elastomer composites

    Directory of Open Access Journals (Sweden)

    Anuvat Sirivat

    2014-11-01

    Full Text Available Perovskite lead zirconate (PbZrO3 was synthesized in an orthorhombic form at a temperature below the Curie temperature, TC. The orthorhombic form is a noncentrosymmetric structure which is capable of spontaneous polarization. Fourier transform infrared (FTIR spectra and X-ray diffraction (XRD patterns confirm the successful synthesis of the lead zirconate; and scanning electron microscopy (SEM micrographs indicate that PbZrO3 particles are moderately dispersed in the natural rubber (NR matrix. Without an electrical field, the particles merely act as a ferroelectric filler, which can absorb and store additional stress. Under an electrical field, particle-induced dipole moments are generated, leading to interparticle interaction and a substantial increase in the storage modulus. At a small amount of lead zirconate particulates present in the natural rubber matrix, at a volume fraction of 0.007306, the electrical conductivity increases dramatically by nearly two orders of magnitude at the electrical frequency of 500 kHz.

  8. Evaluation of peptides release using a natural rubber latex biomembrane as a carrier.

    Science.gov (United States)

    Miranda, M C R; Borges, F A; Barros, N R; Santos Filho, N A; Mendonça, R J; Herculano, R D; Cilli, E M

    2018-05-01

    The biomembrane natural (NRL-Natural Rubber Latex), manipulated from the latex obtained from the rubber tree Hevea brasiliensis, has shown great potential for application in biomedicine and biomaterials. Reflecting the biocompatibility and low bounce rate of this material, NRL has been used as a physical barrier to infectious agents and for the controlled release of drugs and extracts. The aim of the present study was to evaluate the incorporation and release of peptides using a latex biomembrane carrier. After incorporation, the release of material from the membrane was observed using spectrophotometry. Analyses using HPLC and mass spectroscopy did not confirm the release of the antimicrobial peptide [W 6 ]Hylin a1 after 24 h. In addition, analysis of the release solution showed new compounds, indicating the degradation of the peptide by enzymes contained in the latex. Additionally, the release of a peptide with a shorter sequence (Ac-WAAAA) was evaluated, and degradation was not observed. These results showed that the use of NRL as solid matrices as delivery systems of peptide are sequence dependent and could to be evaluated for each sequence.

  9. The improvement in functional characteristics of eco-friendly composites made of natural rubber and cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Araki, Kunihiro; Kaneko, Shonosuke; Matsumoto, Koki; Tanaka, Tatsuya; Arao, Yoshihiko [Applied Materials Engineering Laboratory, Faculty of Engineering, Doshisha University, 1-3, Tatara Miyakodani, Kyotanabe, Kyoto, 610-0321 (Japan); Nagatani, Asahiro [Applied Materials Engineering Laboratory, Faculty of Engineering, Doshisha University, 1-3, Tatara Miyakodani, Kyotanabe, Kyoto, 610-0321 (Japan); Hyogo Prefectural Institute of Technology, 3-1-12, Yukihira-cho, Suma-ku, Kobe, Hyogo, 654-0037 (Japan)

    2015-05-22

    We investigated the efficient use of cellulose to resolve the problem of the depletion of fossil resources. In this study, as the biomass material, the green composite based on natural rubber (NR) and the flake-shaped cellulose particles (FSCP) was produced. In order to further improvement of functional characteristics, epoxidized natural rubber (ENR) was also used instead of NR. The FSCP were produced by mechanical milling in a planetary ball mill with a grinding aid as a cellulose aggregation inhibitor. Moreover, talc and mica particles were used to compare with FSCP. NR and ENR was mixed with vulcanizing agents and then each filler was added to NR compound in an internal mixer. The vulcanizing agents are as follows: stearic acid, zinc oxide, sulfur, and vulcanization accelerator. The functionalities of the composites were evaluated by a vibration-damping experiment and a gas permeability experiment. As a result, we found that FSCP filler has effects similar to (or more than) inorganic filler in vibration-damping and O{sub 2} barrier properties. And then, vibration- damping and O{sub 2} barrier properties of the composite including FSCP was increased with use of ENR. In particular, we found that ENR-50 composite containing 50 phr FSCP has three times as high vibration-damping property as ENR-50 without FSCP.

  10. Thermal Characterization of Modified Tacca Leontopetaloides Starch and Natural Rubber Based Thermoplastic Elastomer

    International Nuclear Information System (INIS)

    Ainatul Mardhiah Mohd Amin; Nur Shahidah Ab Aziz; Nurul Shuhada Mohd Makhtar; Miradatul Najwa Mohd Rodhi; Suhaila Mohd Sauid

    2014-01-01

    The purpose of this study is to identify the potential of Tacca leontopetaloides starch as bio-based thermoplastic elastomers, TPEs. Starch based polymer had been recognized to have highly potential in replace existing source of conventional elastomeric polymer. The modification process of blending starch with natural rubber, plasticizers, additives, and filler contribute to the enhancement and improvement for the properties of starch in order to produce biopolymers by approaching the properties of TPEs. Thermal properties of starch based thermoplastic was studied to evaluate the decomposition and degradation of the samples by using Thermogravimetric Analysis, TGA while the properties of endothermic reactions of the samples were thermally analyzed via Differential Scanning Calorimetry, DSC. From the analysis, it was found that the thermal properties of samples were revealed by recognizing GM-2 (green materials, GM) has high thermal resistance towards high temperature up to 480.06 degree Celsius with higher amount of residue which is 4.97 mg compared to other samples. This indicates GM-2 comprises of superior combination of ratio between natural rubbers and glycerol (plasticizer) in purpose of approaching the properties of Thermoplastic Elastomers, TPEs. (author)

  11. Radiation prevulcanized natural rubber latex: Cytotoxicity and safety evaluation on animal

    Energy Technology Data Exchange (ETDEWEB)

    Keong, C C; Zin, W M Wan; Ibrahim, P; Ibrahim, S, E-mail: chai@nuclearmalaysia.gov.my [Malaysian Nuclear Agency, Bangi, 43000 Kajang, Selangor (Malaysia)

    2010-05-15

    Radiation prevulcanized natural rubber latex (RVNRL) was claimed to be more user friendly than natural rubber latex prevulcanized by sulphur curing system. The absence of Type IV allergy inducing chemicals in RVNRL make it a suitable material for manufacturing of many kinds of latex products, especially those come into direct contact with users. This paper reveals and discusses the findings of cytotoxicity test and safety evaluation on animal for RVNRL. The test was done on RVNRL films prepared by coagulant dipping method and RVNRL dipped products produced by latex dipped product manufacturers. Cytotocixity test was carried out on mammalian cell culture American Type Culture Collection CCL 81, Vero. Results indicated that no cytotoxic effect from RVNRL films and products was found on the cell culture. Two animal studies, namely dermal sensitization study and primary skin irritation study, were done on gloves made from RVNRL. Albino white guinea pigs were used as test subjects in dermal sensitization study and results showed no sensitization induced by the application of test material in the guinea pigs. Primary skin irritation study was done on New Zealand white rabbits and results showed that the product tested was not corrosive and was not a primary irritant

  12. Radiation prevulcanized natural rubber latex: Cytotoxicity and safety evaluation on animal

    International Nuclear Information System (INIS)

    Keong, C C; Zin, W M Wan; Ibrahim, P; Ibrahim, S

    2010-01-01

    Radiation prevulcanized natural rubber latex (RVNRL) was claimed to be more user friendly than natural rubber latex prevulcanized by sulphur curing system. The absence of Type IV allergy inducing chemicals in RVNRL make it a suitable material for manufacturing of many kinds of latex products, especially those come into direct contact with users. This paper reveals and discusses the findings of cytotoxicity test and safety evaluation on animal for RVNRL. The test was done on RVNRL films prepared by coagulant dipping method and RVNRL dipped products produced by latex dipped product manufacturers. Cytotocixity test was carried out on mammalian cell culture American Type Culture Collection CCL 81, Vero. Results indicated that no cytotoxic effect from RVNRL films and products was found on the cell culture. Two animal studies, namely dermal sensitization study and primary skin irritation study, were done on gloves made from RVNRL. Albino white guinea pigs were used as test subjects in dermal sensitization study and results showed no sensitization induced by the application of test material in the guinea pigs. Primary skin irritation study was done on New Zealand white rabbits and results showed that the product tested was not corrosive and was not a primary irritant

  13. Green synthesis of colloidal silver nanoparticles using natural rubber latex extracted from Hevea brasiliensis.

    Science.gov (United States)

    Guidelli, Eder José; Ramos, Ana Paula; Zaniquelli, Maria Elisabete D; Baffa, Oswaldo

    2011-11-01

    Colloidal silver nanoparticles were synthesized by an easy green method using thermal treatment of aqueous solutions of silver nitrate and natural rubber latex (NRL) extracted from Hevea brasiliensis. The UV-Vis spectra detected the characteristic surface plasmonic absorption band around 435 nm. Both NRL and AgNO(3) contents in the reaction medium have influence in the Ag nanoparticles formation. Lower AgNO(3) concentration led to decreased particle size. The silver nanoparticles presented diameters ranging from 2 nm to 100 nm and had spherical shape. The selected area electron diffraction (SAED) patterns indicated that the silver nanoparticles have face centered cubic (fcc) crystalline structure. FTIR spectra suggest that reduction of the silver ions are facilitated by their interaction with the amine groups from ammonia, which is used for conservation of the NRL, whereas the stability of the particles results from cis-isoprene binding onto the surface of nanoparticles. Therefore natural rubber latex extracted from H. brasiliensis can be employed in the preparation of stable aqueous dispersions of silver nanoparticles acting as a dispersing and/or capping agent. Moreover, this work provides a new method for the synthesis of silver nanoparticles that is simple, easy to perform, pollutant free and inexpensive. Copyright © 2011 Elsevier B.V. All rights reserved.

  14. Properties and Characterization of Kenaf-Filled Natural Rubber Latex Foam

    Directory of Open Access Journals (Sweden)

    Ahmad Fikri Abdul Karim

    2015-12-01

    Full Text Available Kenaf powder was incorporated with natural rubber latex (NRL compound and foamed to make natural rubber latex foam (NRLF by using a well known technique called the Dunlop method. Different loadings of kenaf powder were added to NRL compound and was foamed to make NRLF. The mechanical properties, density, compression, thermal, and micro-structural characterization of control NRLF and kenaf incorporated NRLF were studied. Increasing content of kenaf reduced the tensile strength, elongation at break, and compressive strength of a NRLF. Modulus at 100% elongation and density of the NRLF increased with an increase in filler loading. Higher kenaf loading indicated higher elasticity of kenaf-filled NRLF, but the recovery percentage of kenaf-filled NRLF decreased with increasing kenaf loading. From thermogravimetric analysis (TGA result, an increase in the amount of kenaf loading from 1 to 7 phr increased the thermal stability of kenaf-filled NRLF. Morphological and micro-structural characterization performed by using scanning electron microscopy (SEM showed that kenaf powder filled up the micro-sized pores in the open cell structure of kenaf-filled NRLF.

  15. Preparation of Non-Woven Fiber Mats by Mixture of PVC and Epoxidized Natural Rubber

    International Nuclear Information System (INIS)

    Muhammad Hariz Othman; Mahathir Mohamed; Dahlan Mohd

    2014-01-01

    Eletrospun non-woven fibre mats prepared from ENR modified PVC were successfully fabricated at ambient temperature by electro spinning method. Liquid epoxidized natural rubber (LENR) was used because it is easier to handle compared to dried ENR. PVC was mixed with LENR based on 3 different ratios (9:1, 8:2 and 7:3). The effect of ENR on electrospinnibality of PVC was investigated.The morphologies and thermal properties of the electro span fibre mats were characterized and assessed using scanning calorimetry (DSC). The polymer solution concentration 16 aut % formed a diameter of the fibres were mainly affected by the addition of natural rubber and weight ratio of the solution. The diameter of the fibres also decreased with increasing amount of LENR in the solution. Thermal degradation involved two-step degradation with the first degradation representing the dehydro chlorination of PVC to form polyene and followed by the decomposition of LENR and the polyene.Addition of LENR into the sample caused the T g of electro spun fibre mats of PVC/LENR to shift toward lower temperature. (author)

  16. Effect of Modified Natural Rubber on PVC-ENR Electrospun Membrane: Thermal and Morphological Studies

    International Nuclear Information System (INIS)

    Mahathir Mohamed; Dahlan Mohd; Ratnam, C.T.; Pairu Ibrahim

    2016-01-01

    Electrospun fibers membrane (EFM) based on modified epoxidized natural rubber (ENR) and polyvinyl chloride (PVC) was successfully prepared by electro spinning technique. Epoxidized natural rubber was firstly prepared in solution by using 5 L flask and exposed to high intensity UV lamp for degradation. The PVC/ ENR mixture solution concentration were about 16 wt% and blended for 5 hours for homogeneity. The PVC/ ENR mixture were electro spun to form fibers membrane. The sample of electro spun fibers membrane were cured by electron beam. The resulting membranes were characterized for thermal and morphological studies. Thermal decomposition behavior of EFM was analyzed by thermogravimetric analysis (TGA). Thermo gram from TGA showed two stages of degradation for all formulation (90:10, 80:20, 70:30 PVC/ ENR) from 240 to 265 degree Celsius and 400 to 410 degree Celsius, respectively. From the DSC thermo gram of PVC/ ENR electro spun fibers showed that the addition of ENR resulted in the shifting of glass transition temperature (Tg) towards lower temperatures. The morphology of electro spun fibers was examined using scanning electron microscopy and it showed a variety of fiber morphologies. (author)

  17. Electron beam irradiation in natural fibres reinforced polymers (NFRP)

    Energy Technology Data Exchange (ETDEWEB)

    Kechaou, B. [LaMaCoP - Faculte des sciences de Sfax, 3018 Sfax (Tunisia); LTDS-UMR 5513 - Ecole Centrale de Lyon, B.P 163 69134 Ecully Cedex (France); Salvia, M. [LTDS-UMR 5513 - Ecole Centrale de Lyon, B.P 163 69134 Ecully Cedex (France); Fakhfakh, Z. [LaMaCoP - Faculte des sciences de Sfax, 3018 Sfax (Tunisia); Juve, D. [LTDS-UMR 5513 - Ecole Centrale de Lyon, B.P 163 69134 Ecully Cedex (France); Boufi, S. [LSME-Faculte des Sciences de Sfax, 3018 Sfax (Tunisia); Kallel, A. [LaMaCoP - Faculte des sciences de Sfax, 3018 Sfax (Tunisia); Treheux, D. [LTDS-UMR 5513 - Ecole Centrale de Lyon, B.P 163 69134 Ecully Cedex (France)], E-mail: daniel.treheux@ec-lyon.fr

    2008-11-15

    This study focuses on the electric charge motion in unsatured polyester and epoxy composites reinforced by natural fibres of Alfa type, treated by different coupling agents. The electric charging phenomenon is studied by scanning electron microscopy mirror effect (SEMME) coupled with the induced current method (ICM). Previously, using the same approach, glass fibre reinforced epoxy (GFRE) was studied to correlate mechanical [B. Kchaou, C. Turki, M. Salvia, Z. Fakhfakh, D. Treheux, Composites Science and Technology 64 (2004) 1467], or tribological [B. Kchaou, C. Turki, M. Salvia, Z. Fakhfakh, D. Treheux, Dielectric and friction behaviour of unidirectionalglass fibre reinforced epoxy (GFRE), Wear, 265 (2008) 763.] properties and dielectric properties. It was shown that the dielectric properties of the fibre-matrix interfaces play a significant role in the optimization of the composite. This result seems to be the same for natural fibre composites: the fibre-matrix interfaces allow a diffusion of the electric charges which can delocalize the polarization energy and consequently delay the damage of the composite. However, a non-suited sizing can lead to a new trapping of electric charges along these same interfaces with, as a consequence, a localization of the polarisation energy. The optimum composite is obtained for one sizing which helps, at the same time, to have a strong fibre-matrix adhesion and an easy flow of the electric charges along the interface.

  18. Study on the structure-properties relationship of natural rubber/SiO2 composites modified by a novel multi-functional rubber agent

    Directory of Open Access Journals (Sweden)

    S. Y. Yang

    2014-06-01

    Full Text Available Vulcanization property and structure-properties relationship of natural rubber (NR/silica (SiO2 composites modified by a novel multi-functional rubber agent, N-phenyl- N'-(γ-triethoxysilane-propyl thiourea (STU, are investigated in detail. Results from the infrared spectroscopy (IR and X-ray photoelectron spectroscopy (XPS show that STU can graft to the surface of SiO2 under heating, resulting in a fine-dispersed structure in the rubber matrix without the connectivity of SiO2 particles as revealed by transmission electron microscopy (TEM. This modification effect reduces the block vulcanization effect of SiO2 for NR/SiO2/STU compounds under vulcanization process evidently. The 400% modulus and tensile strength of NR/SiO2/STU composites are much higher than that of NR/SiO2/TU composites, although the crystal index at the stretching ratio of 4 and crosslinking densities of NR/SiO2 composites are almost the same at the same dosage of SiO2. Consequently, a structure-property relationship of NR/SiO2/STU composites is proposed that the silane chain of STU can entangle with NR molecular chains to form an interfacial region, which is in accordance with the experimental observations quite well.

  19. Effects of variation of oil and zinc oxide type on the gas barrier and mechanical properties of chlorobutyl rubber/epoxidised natural rubber blends

    International Nuclear Information System (INIS)

    Li, Lin; Zhang, Jin; Jo, Jae Ok; Datta, Sanjoy; Kim, Jin Kuk

    2013-01-01

    Highlights: ► A (90:10) blend of CIIR and ENR by weight was used as the base. ► Different process oil and ZnO were used to optimize the gas barrier property. ► The minimum oxygen permeability is obtained using sheet ZnO. - Abstract: In many polymer applications such as inner tire liners and fuel hoses, imparting excellent gas barrier property is of prime importance. Researches in this direction had been done based on a judicious choice of polymer type or a blend thereof and the compounding ingredients. Though butyl rubber has been the polymer of choice because of its excellent gas barrier property, yet researches were targeted to improve the same with further modification in the polymer type and variation in compounding ingredients. In this study, a (90:10) blend of chlorobutyl rubber (CIIR) and Epoxdised Natural Rubber (ENR) by weight was used as the base. Four different types of process oil and three different types of zinc oxide (ZnO) at fixed predetermined concentrations were used to optimize the gas barrier and mechanical properties. In this blend, recycled aromatic oil (RAE) and sheet zinc oxide were effective in imparting the best overall combination of properties. Scanning Electron Microscopic (SEM) studies of ZnO were done to understand the structure property relationship

  20. Diclofenac Potassium Transdermal Patches Using Natural Rubber Latex Biomembranes as Carrier

    Directory of Open Access Journals (Sweden)

    Natan Roberto de Barros

    2015-01-01

    Full Text Available The aim of this study was to design a compound transdermal patch containing diclofenac potassium (Dic-K using natural rubber latex (NRL biomembrane. The NRL from Hevea brasiliensis is easily manipulated and low cost and presents high mechanical resistance. It is a biocompatible material which can stimulate natural angiogenesis and is capable of adhering cells on its surface. Recent researches have used the NRL for Transdermal Drug Delivery Systems (TDDSs. Dic-K is used for the treatment of rheumatoid arthritis and osteoarthritis and pain relief for postoperative and posttraumatic cases, as well as inflammation and edema. Results showed that the biomembrane can release Dic-K for up to 216 hours. The kinetics of the Dic-K release could be fitted with double exponential function. X-ray diffraction and Fourier Transform Infrared (FTIR spectroscopy show some interaction by hydrogen bound. The results indicated the potential of the compound patch.

  1. Investigation of deformation of elements of three-dimensional reinforced concrete structures located in the soil, interacting with each other through rubber gaskets

    Science.gov (United States)

    Berezhnoi, D. V.; Balafendieva, I. S.; Sachenkov, A. A.; Sekaeva, L. R.

    2017-06-01

    In work the technique of calculation of elements of three-dimensional reinforced concrete substructures located in a soil, interacting with each other through rubber linings is realized. To describe the interaction of deformable structures with the ground, special “semi-infinite” finite elements are used. A technique has been implemented that allows one to describe the contact interaction of three-dimensional structures by means of a special contact finite element with specific properties. The obtained numerical results are compared with the experimental data, their good agreement is noted.

  2. Effects of Rice Husk Modification with Liquid Natural Rubber and Exposure to Electron Beam Radiation on the Mechanical Properties of NR/ HDPE/ Rice Husk Composites

    International Nuclear Information System (INIS)

    Lane, C.E.; Ishak Ahmad; Ibrahim Abdullah; Dahlan Mohd

    2011-01-01

    Rice husk (RH) powder is a natural fibre capable of reinforcing natural rubber thermoplastic (TPNR) NR/ HDPE composites on specific modification of the particle surface. In this study the modification of RH powder involved pre-treatment with 5 % sodium hydroxide (NaOH) solution, soaking in LNR solution and exposure of LNR coated RH to electron beam (EB) irradiation. Preparation of NR/ HDPE/ RH composites was via melt-mixing in an internal mixer at predetermined conditions. Morphology study of the composites using scanning electron microscope (SEM) showed a homogeneous distribution of modified RH particles and particle-matrix interaction in the composite. Modified RH filled composites exhibited a significant change in mechanical properties. The maximum stress and impact strength were 6.7 MPa and 13.2 kJ/ m 2 , respectively at 20 kGy radiation, while the tensile modulus was 79 MPa at 30 kGy dose. The interfacial RH-TPNR interaction for the LNR-EB treated RH particles had improved in the EB dosage range of 20-30 kGy. However, over exposure to radiation caused degradation of rubber coat and interaction between particles to increase. Agglomeration of filler particles would occur and caused inhomogeneous distribution of filler in the composite. (author)

  3. Adhesion property of epoxidized natural rubber (ENR-based adhesives containing calcium carbonate

    Directory of Open Access Journals (Sweden)

    2008-06-01

    Full Text Available The adhesion property (i.e. viscosity, loop tack and peel strength of epoxidized natural rubber (ENR 25 and ENR 50 grade-based pressure-sensitive adhesive was studied in the presence of calcium carbonate. The range of calcium carbonate loaded was from 10 to 50 parts per hundred parts of rubber (phr. Coumarone-indene resin was used as the tackifier and its concentration was fixed at 80 phr. Toluene was chosen as the solvent throughout the investigation. The substrates (PET film/paper were coated with the adhesive using a SHEEN hand coater at a coating thickness of 60 µm. Viscosity of the adhesive was measured by a HAAKE Rotary Viscometer whereas loop tack and peel strength were determined by a Llyod Adhesion Tester operating at 30 cm/min. Results show that viscosity of ENR-based adhesives increases gradually with increase in calcium carbonate loading due to the concentration effect of the filler. However, for loop tack and peel strength, it passes through a maximum at 30 phr calcium carbonate, an observation which is attributed to the optimum wettability of adhesive on the substrate at this adhesive composition. ENR 25-based adhesive consistently exhibits higher adhesion property than ENR 50 for all calcium carbonate loadings studied.

  4. Water absorption and mechanical properties of water-swellable natural rubber

    Directory of Open Access Journals (Sweden)

    Diew Saijun

    2009-11-01

    Full Text Available Water-swellable rubber (WSR was prepared by blending superabsorbent polymer (SAP of crosslinked poly(acrylamide-co-sodium acrylate with natural rubber in latex condition. The crosslinked poly(acrylamide-co-sodium acrylate was first prepared by inverse suspension polymerization from acrylamide and sodium acrylate monomers with potassiumpersulfate initiator and N,N-methylenebisacrylamide crosslinker. The reaction was carried out at 60oC for 40 mins. Water absorption properties, such as the degree of water absorption, water absorption rate, degree of weight loss, and mechanicalproperties of WSR were then investigated. It was found that the degree of water absorption, water absorption rate, and thedegree of weight loss increased, while tensile strength and elongation at break decreased with increasing quantity of SAP inthe blends. However, the degree of water absorption, degree of weight loss, and elongation at break decreased, but tensilestrength increased with increasing quantity of the N-tert-butyl-2-benzothiazyl sulphenamide (TBBS accelerator used in thecompounds formulation.

  5. Engineering Properties of Treated Natural Hemp Fiber-Reinforced Concrete

    Directory of Open Access Journals (Sweden)

    Xiangming Zhou

    2017-06-01

    Full Text Available In recent years, the construction industry has seen a significant rise in the use of natural fibers, for producing building materials. Research has shown that treated hemp fiber-reinforced concrete (THFRC can provide a low-cost building material for residential and low-rise buildings, while achieving sustainable construction and meeting future environmental targets. This study involved enhancing the mechanical properties of hemp fiber-reinforced concrete through the Ca(OH2 solution pretreatment of fibers. Both untreated (UHFRC and treated (THFRC hemp fiber-reinforced concrete were tested containing 15-mm length fiber, at a volume fraction of 1%. From the mechanical strength tests, it was observed that the 28-day tensile and compressive strength of THFRC was 16.9 and 10% higher, respectively, than UHFRC. Based on the critical stress intensity factor (KICs and critical strain energy release rate (GICs, the fracture toughness of THFRC at 28 days was also found to be 7–13% higher than UHFRC. Additionally, based on the determined brittleness number (Q and modulus of elasticity, the THFRC was found to be 11% less brittle and 10.8% more ductile. Furthermore, qualitative analysis supported many of the mechanical strength findings through favorable surface roughness observed on treated fibers and resistance to fiber pull-out.

  6. Performance of magnetorheological elastomer based green epoxidized natural rubber/sucrose acetate isobutyrate hybrid matrix

    Science.gov (United States)

    Khairi, Muntaz Hana Ahmad; Amri Mazlan, Saiful; Aziz, Siti Aishah Abdul; Ubaidillah; Tan Shilan, Salihah

    2018-04-01

    This study introduces a sucrose acetate isobutyrate (SAIB) as a novel additive of magnetorheological elastomers (MREs). The MREs utilized an epoxidized natural rubber (ENR) as the matrix and carbonyl iron particles (CIPs) as their filler. The CIPs were fixed at 60 wt%. The viscosity of the compound was observed using a viscometer. Meanwhile, the microstructures were observed by using field emission scanning electron microscope (FESEM). Rheological properties regarding shear storage modulus were measured by using a rheometer (MCR 302, Anton Paar). The experimental results demonstrated that the MREs-based ENR/SAIB had a decrement in their viscosity by 40% reduction. Moreover, the magnetorheological (MR) effect increased by 23% as the increment of magnetic fields. The morphological photograph showed that the CIPs embedded well within the matrix. The fabricated MREs samples were strain dependent, where all MREs samples exhibit the deteriorating trend when increasing the strain amplitude.

  7. Effect of bentonite modification on hardness and mechanical properties of natural rubber nanocomposites

    International Nuclear Information System (INIS)

    Santiago, Denise Ester O.; Pajarito, Bryan B.; Mangaccat, Winna Faye F.; Tigue, Maelyn Rose M.; Tipton, Monica T.

    2016-01-01

    The effect of sodium activation, ion-exchange with tertiary amine salt, surface treatment with non-ionic surfactant, and wet grinding of bentonite on hardness and mechanical properties of natural rubber nanocomposites (NRN) was studied using full factorial design of experiment. Results of X-ray diffraction (XRD) show increase in basal spacing d of bentonite due to modification, while attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) confirm the organic modification of bentonite. Analysis of variance (ANOVA) shows that the main effect of surface treatment increases the hardness and decreases the tensile modulus of the NRN. The surface treatment and wet grinding of bentonite decrease the tensile stresses at 100, 200 and 300% strain of NRN. Sodium activation and ion-exchange negatively affect the compressive properties, while surface treatment significantly improves the compressive properties of NRN.

  8. Antifungal activity of fluconazole-loaded natural rubber latex against Candida albicans.

    Science.gov (United States)

    Yonashiro Marcelino, Mônica; Azevedo Borges, Felipe; Martins Costa, Ana Flávia; de Lacorte Singulani, Junya; Ribeiro, Nathan Vinícius; Barcelos Costa-Orlandi, Caroline; Garms, Bruna Cambraia; Soares Mendes-Giannini, Maria José; Herculano, Rondinelli Donizetti; Fusco-Almeida, Ana Marisa

    2018-03-01

    This work aimed to produce a membrane based on fluconazole-loaded natural rubber latex (NRL), and study their interaction, drug release and antifungal susceptibility against Candida albicans. Fluconazole-loaded NRL membrane was obtained by casting method. The Fourier Transform Infrared Spectroscopy showed no modifications either in NRL or fluconazole after the incorporation. Mechanical test presented low Young's modulus and high strain, indicating the membranes have sufficient elasticity for biomedical application. The bio-membrane was able to release the drug and inhibit the growth of C. albicans as demonstrated by disk diffusion and macrodilution assays. The biomembrane was able to release fluconazole and inhibit the growth of C. albicans, representing a promising biomaterial for skin application.

  9. Data for effects of lanthanum complex on the thermo-oxidative aging of natural rubber

    Directory of Open Access Journals (Sweden)

    Wei Zheng

    2015-12-01

    Full Text Available Novel mixed antioxidants composed of antioxidant IPPD and lanthanum (La complex were added as a filler to form natural rubber (NR composites. By mechanical testing, Fourier transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR and thermogravimetric analysis (TGA, a string of data, including the mechanical properties, the variation of internal groups and the thermal and thermo-oxidative decompositions of NR, was presented in this data article. The data accompanying its research article [1] studied the thermo-oxidative aging properties of NR in detail. The density function theoretical (DFT calculations were also used as an assistant to study the thermo-oxidative aging mechanism of NR. The data revealed that this new rare-earth antioxidant could indeed enhance the thermo-oxidative aging resistance of NR, which is associated with its different function mechanism from that of the pure antioxidant IPPD.

  10. Effect of bentonite modification on hardness and mechanical properties of natural rubber nanocomposites

    Science.gov (United States)

    Santiago, Denise Ester O.; Pajarito, Bryan B.; Mangaccat, Winna Faye F.; Tigue, Maelyn Rose M.; Tipton, Monica T.

    2016-05-01

    The effect of sodium activation, ion-exchange with tertiary amine salt, surface treatment with non-ionic surfactant, and wet grinding of bentonite on hardness and mechanical properties of natural rubber nanocomposites (NRN) was studied using full factorial design of experiment. Results of X-ray diffraction (XRD) show increase in basal spacing d of bentonite due to modification, while attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) confirm the organic modification of bentonite. Analysis of variance (ANOVA) shows that the main effect of surface treatment increases the hardness and decreases the tensile modulus of the NRN. The surface treatment and wet grinding of bentonite decrease the tensile stresses at 100, 200 and 300% strain of NRN. Sodium activation and ion-exchange negatively affect the compressive properties, while surface treatment significantly improves the compressive properties of NRN.

  11. Data for effects of lanthanum complex on the thermo-oxidative aging of natural rubber.

    Science.gov (United States)

    Zheng, Wei; Liu, Li; Zhao, Xiuying; He, Jingwei; Wang, Ao; Chan, Tung W; Wu, Sizhu

    2015-12-01

    Novel mixed antioxidants composed of antioxidant IPPD and lanthanum (La) complex were added as a filler to form natural rubber (NR) composites. By mechanical testing, Fourier transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR) and thermogravimetric analysis (TGA), a string of data, including the mechanical properties, the variation of internal groups and the thermal and thermo-oxidative decompositions of NR, was presented in this data article. The data accompanying its research article [1] studied the thermo-oxidative aging properties of NR in detail. The density function theoretical (DFT) calculations were also used as an assistant to study the thermo-oxidative aging mechanism of NR. The data revealed that this new rare-earth antioxidant could indeed enhance the thermo-oxidative aging resistance of NR, which is associated with its different function mechanism from that of the pure antioxidant IPPD.

  12. Formation of protein complex with the aid of polyethylene glycol for deproteinized natural rubber latex

    Science.gov (United States)

    Wei, Lim Keuw; Ing, Wong Kwee; Badri, Khairiah Haji; Ban, Wong Chong

    2013-11-01

    The effect of polyethylene glycol (PEG) as a deproteinizing agent in commercial natural rubber latex (NRL) onto the physicochemical properties of the NRL was investigated. Three types of PEG were used namely PEG200, PEG4000 and PEG20000 (molecular weight of 200, 4000 and 20000 g/mol respectively). The optimum amount of PEG in NRL was determined from viscosity changes, protein content and Fourier Transform Infrared spectroscopy. Level of protein reduction was affected by molecular weight of PEG. The addition of PEG in NRL reduced the protein content of NRL (3.30 %) to the lowest (2.01 %) at 0.40 phr of PEG200 due to more attractive hydrophobic interactions between short chains PEG compared to PEG4000 (2.24%) and PEG20000 (2.15%). This was verified through FTIR spectroscopy analysis by observing the primary and secondary amide peak where PEG4000 has lesser absorption at the region compared to with PEG20000.

  13. Radiation graft copolymerization of n-butyl acrylate on natural rubber latex

    International Nuclear Information System (INIS)

    Sundardi, F.; Kadariah, S.

    1986-01-01

    A method of radiation graft copolymerization of n-butyl acrylate (NBA) on natural rubber (NR) latex has been studied. The rate of conversion increases with the increase of NBA in latex. An irradiation dose of about 12 kGy is needed to obtain 90% conversion with 40 phr of NBA in latex. Tensile strength, tear strength, and elongation at break of grafted NR are found to decrease with increasing degree of grafting. The physical strength of a vulcanizate prepared from a mixture of NR and ply-NBA was found to be better than that of NBA-NR graft copolymer vulcanizate. The graft copolymerization reaction takes place in the outer layer of NR particles, and because the secondary bonds between poly-NBA molecules may be weaker than those between NR molecules, the existence of a poly-NBA layer in NR particles will decrease its physical strength

  14. Characteristic of natural rubber latex-methyl metha-crylate copolymer in mineral lubricant base oil

    International Nuclear Information System (INIS)

    Meri Suhartini; Rahmawati

    2010-01-01

    Natural rubber latex-methyl methacrylate copolymer was diluted in xylene, then diluted in four types of lubricant base oil with concentrations of 0.25%, 1%, 5%, and 10%. The mixed solutions were analyzed to obtain kinematics viscosity, viscosity index, density, ash content, metal content, flash point, shear stability and total alkali number. The viscosity index of sample, increased by adding the copolymer solution. The results showed that lubricant base oil of High Viscosity index (HVI) 60 and mixed HVI 60: HVI 650 gave optimum viscosity index. The higher concentration of polymer added into base lubricant oil, the higher viscosity index obtained. The shear stability test showed that the kinematics viscosity of sample decreased 6.5% after 60 minutes of treatment test. (author)

  15. Effect of bentonite modification on hardness and mechanical properties of natural rubber nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Santiago, Denise Ester O. [Polymer Research Laboratory, Department of Chemical Engineering, University of the Philippines, Diliman, Quezon City 1101 Philippines (Philippines); Department of Chemical Engineering, University of the Philippines, Los Baños, College, Laguna 4031 Philippines (Philippines); Pajarito, Bryan B.; Mangaccat, Winna Faye F.; Tigue, Maelyn Rose M.; Tipton, Monica T. [Polymer Research Laboratory, Department of Chemical Engineering, University of the Philippines, Diliman, Quezon City 1101 Philippines (Philippines)

    2016-05-18

    The effect of sodium activation, ion-exchange with tertiary amine salt, surface treatment with non-ionic surfactant, and wet grinding of bentonite on hardness and mechanical properties of natural rubber nanocomposites (NRN) was studied using full factorial design of experiment. Results of X-ray diffraction (XRD) show increase in basal spacing d of bentonite due to modification, while attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) confirm the organic modification of bentonite. Analysis of variance (ANOVA) shows that the main effect of surface treatment increases the hardness and decreases the tensile modulus of the NRN. The surface treatment and wet grinding of bentonite decrease the tensile stresses at 100, 200 and 300% strain of NRN. Sodium activation and ion-exchange negatively affect the compressive properties, while surface treatment significantly improves the compressive properties of NRN.

  16. n-BA/KOH/t-BHP behaviour in the natural rubber latex vulcanization by gamma rays

    International Nuclear Information System (INIS)

    Souza, A. de.

    1994-01-01

    Natural rubber latex was vulcanized in the absence and in the presence of sensitizer (S), with gamma ray from 60 Co source, panoramic type, at the dose rate range of 1,20-1,33 kGy/h. The components of used S were n-butyl acrylate (n-BA), the KOH as stabilizer and t-butyl hydroperoxide (t-BHP) as co-S. The purpose of this work was to study the efficiency and the behaviour of each component of S in the irradiated latex crosslinking by tensile strength (T b ), volume fraction and permanent set. In the absence of S occur straight crosslinking between macromolecular adjacent radicals. IN the presence of S, the n-BA participates in the crosslinking through acrylic bridges between macromolecules. (author)

  17. Data for effects of lanthanum complex on the thermo-oxidative aging of natural rubber

    Science.gov (United States)

    Zheng, Wei; Liu, Li; Zhao, Xiuying; He, Jingwei; Wang, Ao; Chan, Tung W.; Wu, Sizhu

    2015-01-01

    Novel mixed antioxidants composed of antioxidant IPPD and lanthanum (La) complex were added as a filler to form natural rubber (NR) composites. By mechanical testing, Fourier transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR) and thermogravimetric analysis (TGA), a string of data, including the mechanical properties, the variation of internal groups and the thermal and thermo-oxidative decompositions of NR, was presented in this data article. The data accompanying its research article [1] studied the thermo-oxidative aging properties of NR in detail. The density function theoretical (DFT) calculations were also used as an assistant to study the thermo-oxidative aging mechanism of NR. The data revealed that this new rare-earth antioxidant could indeed enhance the thermo-oxidative aging resistance of NR, which is associated with its different function mechanism from that of the pure antioxidant IPPD. PMID:26693513

  18. Effect of electron beam-cross-linked gels on the rheological properties of raw natural rubber

    Energy Technology Data Exchange (ETDEWEB)

    Mitra, Suman; Chattopadhyay, Santanu [Rubber Technology Centre, Indian Institute of Technology, Kharagpur, West Bengal 721302 (India); Bharadwaj, Y.K.; Sabharwal, S. [Radiation Technology Development Section, Bhabha Atomic Research Center, Trombay, Mumbai 400085 (India); Bhowmick, Anil K. [Rubber Technology Centre, Indian Institute of Technology, Kharagpur, West Bengal 721302 (India)], E-mail: anilkb@rtc.iitkgp.ernet.in

    2008-05-15

    Electron beam (EB)-cross-linked natural rubber (NR) gels were prepared from latex and characterized by various techniques. The addition of a small amount of these gels to raw NR was found to reduce the apparent shear viscosity and die swell remarkably. This effect was further enhanced with the addition of butyl acrylate as a sensitizer. The apparent shear viscosity first decreased up to 8 phr of gel loading and then increased. However, the percent die swell value decreased steadily upon gel loading. These were explained by calculating principal normal stress difference, the activation energy of melt flow and characteristics of EB-cross-linked gels. These effects were also reflected in the changes of mechanical and dynamic mechanical properties of gel-filled raw NR. Tailoring of the above properties could be done with the help of these gels.

  19. Investigation on magnetic field dependent modulus of epoxidized natural rubber based magnetorheological elastomer

    International Nuclear Information System (INIS)

    Yunus, N. A.; Mazlan, S. A.; Ubaidillah; Aziz, S. A. A.; Khairi, M. H. Ahmad; Wahab, N. A. A.; Shilan, S. T.

    2016-01-01

    This paper presents an investigation on the use of epoxidized natural rubber (ENR) as a matrix of magnetorheological elastomers (MREs). Isotropic ENR-based MRE samples were synthesized by homogeneously mixed the ENR compound with carbonyl iron particles (CIPs). The microstructure of the sample was observed, and the magnetic field-dependent moduli were analyzed using rheometer. The influences of excitation frequency, CIPs content and magnetic field on the field-dependent moduli of ENR-based MREs were evaluated through dynamic shear test. The microstructure of MRE samples demonstrated the dispersed CIPs in the ENR matrix. The remarkable increment of storage and loss moduli of the ENR-based MREs has exhibited the magnetically controllable storage and loss moduli of the samples when exposed to the magnetic field. Consequently, the CIPs content, frequency and magnetic field were significantly influenced the dynamic moduli of the ENR-based MREs. (paper)

  20. Radiation vulcanization of natural rubber latex (NRL) using low energy electron beam accelerator

    International Nuclear Information System (INIS)

    Feroza Akhtar; Keizo Makuuchi; Fumio Yoshii

    1996-01-01

    The electron beam induced vulcanization of natural rubber latex has been studied using low energy Electron Beam (EB) accelerators of 300, 250 and 175 keV ne latex was irradiated in a special type stainless steel reaction reactor with a stirrer at the bottom of the reactor. From the results it was found that 300 and 250 keV accelerators could effectively vulcanize NRL. But accelerator of 175 keV is too low energy to vulcanize the latex. At the same time a drum type irradiator where thin layer of NRL was irradiated by accelerator, was used for vulcanization of NRL. This type of irradiator also showed good physical properties of vulcanized latex. The effects of beam current and stirrer speed on vulcanization were studied

  1. Toxicological evaluation of natural rubber latex film vulcanized with ionizing radiation

    International Nuclear Information System (INIS)

    Campos, Vania E.; Higa, Olga Z.; Guedes, Selma M.L.; Hanada, Seico

    1999-01-01

    The industrial vulcanization of natural rubber latex (NRL) is made worldwide by conventional process using sulphur, but it can be made by an alternative process using ionizing radiation. The main advantages of this process are related to absence of toxic effect promoted by chemical substances added to the NRL on the conventional process. In this research was tested the toxicological properties of the films vulcanized by the alternative process in relation to that vulcanized by the conventional process. The toxicity was evaluated by in vitro cytotoxicity assay and in vivo systemic toxicity assay. The results showed that vulcanized films by gamma ray are less cytotoxic. The systemic toxicity assay showed that only the vulcanized film using sulphur induced allaying and motor in coordination on the animals for a short period of time. these results evidence the less cytotoxic properties of vulcanized films by gamma ray in relation to that vulcanized by conventional process using sulphur. (author)

  2. STRAIN-CONTROLLED BIAXIAL TENSION OF NATURAL RUBBER: NEW EXPERIMENTAL DATA

    KAUST Repository

    Pancheri, Francesco Q.

    2014-03-01

    We present a new experimental method and provide data showing the response of 40A natural rubber in uniaxial, pure shear, and biaxial tension. Real-time biaxial strain control allows for independent and automatic variation of the velocity of extension and retraction of each actuator to maintain the preselected deformation rate within the gage area of the specimen. Wealso focus on the Valanis-Landel hypothesis that is used to verify and validate the consistency of the data.Weuse a threeterm Ogden model to derive stress-stretch relations to validate the experimental data. The material model parameters are determined using the primary loading path in uniaxial and equibiaxial tension. Excellent agreement is found when the model is used to predict the response in biaxial tension for different maximum in-plane stretches. The application of the Valanis-Landel hypothesis also results in excellent agreement with the theoretical prediction.

  3. Properties of natural rubber/attapulgite composites prepared by latex compounding method: Effect of filler loading

    International Nuclear Information System (INIS)

    Muttalib, Siti Nadzirah Abdul; Othman, Nadras; Ismail, Hanafi

    2015-01-01

    This paper reports on the effect of filler loading on properties of natural rubber (NR)/attapulgite (ATP) composites. The NR/ATP composites were prepared by latex compounding method. It is called as masterbatch. The masterbatch was subsequently added to the NR through melt mixing process. The vulcanized NR/ATP composites were subjected to mechanical, swelling and morphological tests. All the results were compared with NR/ATP composites prepared by conventional system. The composites from masterbatch method showed better results compared to composites prepared by conventional method. They have higher tensile properties, elongation at break and tear strength. The images captured through scanning electron microscopy test revealed the improvement of tensile strength in masterbatch NR/ATP composites. It can be seen clearly that masterbatch NR/ATP have better filler dispersion compared to conventional method NR/ATP composites

  4. Properties of natural rubber/attapulgite composites prepared by latex compounding method: Effect of filler loading

    Energy Technology Data Exchange (ETDEWEB)

    Muttalib, Siti Nadzirah Abdul, E-mail: sitinadzirah.amn@gmail.com; Othman, Nadras, E-mail: srnadras@usm.my; Ismail, Hanafi, E-mail: ihanafi@usm.my [School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, Seri Ampangan, 14300 Nibong Tebal, Pulau Pinang (Malaysia)

    2015-07-22

    This paper reports on the effect of filler loading on properties of natural rubber (NR)/attapulgite (ATP) composites. The NR/ATP composites were prepared by latex compounding method. It is called as masterbatch. The masterbatch was subsequently added to the NR through melt mixing process. The vulcanized NR/ATP composites were subjected to mechanical, swelling and morphological tests. All the results were compared with NR/ATP composites prepared by conventional system. The composites from masterbatch method showed better results compared to composites prepared by conventional method. They have higher tensile properties, elongation at break and tear strength. The images captured through scanning electron microscopy test revealed the improvement of tensile strength in masterbatch NR/ATP composites. It can be seen clearly that masterbatch NR/ATP have better filler dispersion compared to conventional method NR/ATP composites.

  5. The role of proteins on the thermal oxidative aging of radiation vulcanized natural rubber latex

    International Nuclear Information System (INIS)

    Abad, L.V.; Rosa, A. de la; Keizo Makuuchi; Fumio Yoshii

    1996-01-01

    The effect of Hevea latex proteins on the aging properties of radiation vulcanized natural rubber latex (RVNRL) was investigated. Unpurified RVNRL films exhibited better aging properties than the purified RVNRL films. A sharp decrease in tensile strength was observed after aging when RVNRL films were leached in 1% NH sub 4 OH. However, when these films were soaked in ethanol prior to leaching, the aging properties approximated those of the unleached samples. Kjeldahl and FT-IR analyses of the leached and unleached RVNRL films indicated a higher protein content for both the unleached and ethanol-soaked films than for leached films. Electrophoretic analysis of the proteins present in the NH, extracts of leached RVNRL films showed a high concentration of hevein. This protein was not found in the ATH, extracts of ethanol soaked films. Hevein was shown to improve the aging properties of RVNRL

  6. FTIR and morphology of liquid epoxidized natural rubber acrylate (LENRA)/silica hybrid composites

    International Nuclear Information System (INIS)

    Eda Yuhana Ariffin; Azizan Ahmad; Dahlan Mohd; Mahathir Mohamed

    2009-01-01

    Synthesis of organic-inorganic hybrid composites was carried out by combination of liquid epoxidized natural rubber acrylate (LENRA) and silica. Silica was introduce to the matrix by sol gel technique. The sol-gel technique was employed to prepare silica using tetraethyorthosilicate (TEOS) as precursor. HDDA and irga cure 184 were added to the formulations as reactive diluents and photosensitizer, respectively. The chemical modification was studied by Fourier Transform Infrared (FTIR) and energy dispersive X-ray analysis (EDAX). The morphological studies were conducted by the optical and scanning electron microscopes (SEM). It shows that silica was dispersed very well in the matrix for lower concentration of TEOS while agglomeration occurs at the higher concentration. The average particles size of silica were less than 100 nm. (Author)

  7. Performance of Lightweight Natural-Fiber Reinforced Concrete

    Directory of Open Access Journals (Sweden)

    Hardjasaputra Harianto

    2017-01-01

    Full Text Available Concrete, the most common construction material, has negligible tension capacity. However, a reinforcement material such as natural fibers, can be used to improve the tensile properties of concrete. This paper presents experiments conducted on Super Lightweight Concrete mixed with coconut fibers (SLNFRC. Coconut fibers are regarded as one of the toughest natural fibers to strengthen concrete. Coconut fiber reinforced composites have been considered as a sustainable construction material because the fibers are derived from waste. These wastes, which are available in large quantities in Asia, have to be extracted from the husk of coconut fruits and must pass a mechanical process before being added to a concrete mixture. The Super Lightweight Concrete was made by mixing concrete paste with foam agent that can reduce the overall weight of concrete up to 60% with compressive strength up to 6 MPa. The Super Lightweight Concrete is intended to be used for non-structural walls, as alternative conventional construction materials such as brick walls. The influence of coconut fibers content in increasing the flexural tensile strength of Super Lightweight Concrete was studied in this research. The fiber content studied include 0%, 0.1%, 0.175%, and 0.25% by weight of cement content. Sixteen specimens of SLNFRC mini beams of 60 mm x 60 mm x 300 mm were tested to failure to investigate their flexural strengths. The optimum percent fibers yielding higher tensile strength was found to be 0.175%

  8. Structural characterization and mechanical properties of polypropylene reinforced natural fibers

    Science.gov (United States)

    Karim, M. A. A.; Zaman, I.; Rozlan, S. A. M.; Berhanuddin, N. I. C.; Manshoor, B.; Mustapha, M. S.; Khalid, A.; Chan, S. W.

    2017-10-01

    Recently the development of natural fiber composite instead of synthetics fiber has lead to eco-friendly product manufacturing to meet various applications in the field of automotive, construction and manufacturing. The use of natural fibers offer an alternative to the reinforcing fibers because of their good mechanical properties, low density, renewability, and biodegradability. In this present research, the effects of maleic anhydride polypropylene (MAPP) on the mechanical properties and material characterization behaviour of kenaf fiber and coir fiber reinforced polypropylene were investigated. Different fractions of composites with 10wt%, 20wt% and 30wt% fiber content were prepared by using brabender mixer at 190°C. The 3wt% MAPP was added during the mixing. The composites were subsequently molded with injection molding to prepare the test specimens. The mechanical properties of the samples were investigated according to ISO 527 to determine the tensile strength and modulus. These results were also confirmed by the SEM machine observations of fracture surface of composites and FTIR analysis of the chemical structure. As the results, the presence of MAPP helps increasing the mechanical properties of both fibers and 30wt% kenaf fiber with 3wt% MAPP gives the best result compare to others.

  9. Investigation of crack paths in natural fibre-reinforced composites

    Directory of Open Access Journals (Sweden)

    S. Keck

    2015-10-01

    Full Text Available Nowadays, fibre-reinforced composite materials are widely used in many fields, e.g. automotive and aerospace. Natural fibres such as flax and hemp provide good density specific mechanical properties. Additionally, the embodied production energy in natural fibres is much smaller than in synthetic ones. Within this paper the fracture mechanical behaviour of flax fibre-reinforced composites is discussed. Especially, this paper focuses on the determination and investigation of crack paths in compact tension specimens with three different fibre directions under a static as well as fatigue load. Differences and similarities in the obtained crack paths under different loading conditions are presented. Due to the pronounced orthotropic behaviour of those materials the crack path is not only governed by the stress state, but practically determined by the fibre direction and fibre volume fraction. Therefore, the well-known stress intensity factor solutions for the standard specimens are not applicable. It is necessary to carry out extensive numerical simulations to evaluate the stress intensity factor evolution along the growing crack in order to be able to determine fatigue crack growth rate curves. Those numerical crack growth simulations are performed with the three-dimensional crack simulation program ADAPCRACK3D to gain energy release rates and in addition stress intensity factors

  10. A smart surface from natural rubber: the mechanism of entropic control at the surface monitored by contact angle measurement

    Directory of Open Access Journals (Sweden)

    Sureurg Khongtong

    2006-03-01

    Full Text Available Surface oxidation of crosslinked natural rubber provided a hydrophilic substrate (sticky surface that became more hydrophobic (less sticky when equilibrated against hot water. This unusual temperaturedependent surface reconstruction is interpreted as the result of recoiling of entropic unfavorable uncoiled chains induced when rubber surface was oxidized. Subsequent equilibration of these annealed samples against water at room temperature returned their original hydrophilicity. The degree of this surface reconstruction and its kinetics are also dependent on the amounts of crosslinking of the samples.

  11. Preparation of Low Allergenic Protein Concentrated Natural Rubber Latex Using Suitable Low Molecular Weight Cellulose Derivatives Induced by Gamma Irradiation

    International Nuclear Information System (INIS)

    Siri-Upathum, Chyagrit; Boonyawat, Jariya

    2007-08-01

    Full text: Low molecular weight carboxy methyl cellulose (CMC), hydroxyl ethyl cellulose (HEC), hydroxyl propyl cellulose (HPC) and methyl cellulose (MC) prepared by radiation-induced degradation were added into diluted natural concentrated latex prior to centrifuge for a purpose of reducing allergenic rubber protein in the latex. Optimum molecular weight (Mv) of CMC and HEC for such a purpose was found to be 17-18 kDa which decreased allergenic rubber protein (14-94 kDa) to an undetectable amount as determined by SDS PAGE method

  12. Morphological Study on Room-Temperature-Cured PMMA-Grafted Natural Rubber-Toughened Epoxy/Layered Silicate Nanocomposite

    Directory of Open Access Journals (Sweden)

    N. Y. Yuhana

    2012-01-01

    Full Text Available A morphological study was conducted on ternary systems containing epoxy, PMMA-grafted natural rubber, and organic chemically modified montmorillonite (Cloisite 30B. Optical microscopy, transmission electron microscopy (TEM, scanning electron microscopy (SEM, energy dispersive X-ray (EDX, and wide-angle X-ray diffraction (WAXD analysis were used. The following four materials were prepared at room temperature: cured unmodified epoxy, cured toughened epoxy, cured unmodified epoxy/Cloisite 30B nanocomposites, and cured toughened epoxy/Cloisite 30B nanocomposites. Mixing process was performed by mechanical stirring. Poly(etheramine was used as the curing agent. The detailed TEM images revealed co-continuous and dispersed spherical rubber in the epoxy-rubber blend, suggesting a new proposed mechanism of phase separation. High-magnification TEM analysis showed good interactions between rubber and Cloisite 30B in the ternary system. Also, it was found that rubber particles could enhance the separation of silicates layers. Both XRD and TEM analyses confirmed that the intercalation of Cloisite 30B was achieved. No distinct exfoliated silicates were observed by TEM. Aggregates of layered silicates (tactoids were observed by SEM and EDX, in addition to TEM at low magnification. EDX analysis confirmed the presence of organic and inorganic elements in the binary and ternary epoxy systems containing Cloisite 30B.

  13. Natural Kenaf Fiber Reinforced Composites as Engineered Structural Materials

    Science.gov (United States)

    Dittenber, David B.

    The objective of this work was to provide a comprehensive evaluation of natural fiber reinforced polymer (NFRP)'s ability to act as a structural material. As a chemical treatment, aligned kenaf fibers were treated with sodium hydroxide (alkalization) in different concentrations and durations and then manufactured into kenaf fiber / vinyl ester composite plates. Single fiber tensile properties and composite flexural properties, both in dry and saturated environments, were assessed. Based on ASTM standard testing, a comparison of flexural, tensile, compressive, and shear mechanical properties was also made between an untreated kenaf fiber reinforced composite, a chemically treated kenaf fiber reinforced composite, a glass fiber reinforced composite, and oriented strand board (OSB). The mechanical properties were evaluated for dry samples, samples immersed in water for 50 hours, and samples immersed in water until saturation (~2700 hours). Since NFRPs are more vulnerable to environmental effects than synthetic fiber composites, a series of weathering and environmental tests were conducted on the kenaf fiber composites. The environmental conditions studied include real-time outdoor weathering, elevated temperatures, immersion in different pH solutions, and UV exposure. In all of these tests, degradation was found to be more pronounced in the NFRPs than in the glass FRPs; however, in nearly every case the degradation was less than 50% of the flexural strength or stiffness. Using a method of overlapping and meshing discontinuous fiber ends, large mats of fiber bundles were manufactured into composite facesheets for structural insulated panels (SIPs). The polyisocyanurate foam cores proved to be poorly matched to the strength and stiffness of the NFRP facesheets, leading to premature core shear or delamination failures in both flexure and compressive testing. The NFRPs were found to match well with the theoretical stiffness prediction methods of classical lamination

  14. Cross-border forest disturbance and the role of natural rubber in mainland Southeast Asia using annual Landsat time series

    DEFF Research Database (Denmark)

    Grogan, Kenneth; Pflugmacher, Dirk; Hostert, Patrick

    2015-01-01

    ) are there cross border differences in frontier and non-frontier forest disturbance rates between Cambodia and Vietnam, 3) what proportion of disturbances in frontier and non-frontier forests can be accounted for by the impact of rubber plantations, and 4) is there a relationship between global market prices...... rates related to rubber plantation expansion and price fluctuations of natural rubber. This suggests links between localized land cover/use change and international market forces, irrespective of differing political and socioeconomic backgrounds. Our study underlines the value of using dense Landsat...... that this approach can provide accurate forest disturbance maps but that accuracy is affected by forest type. Highest accuracies were found in evergreen forest (90%), with lower accuracies in mixed (80%) and dry-deciduous forest types (83%). Our final map considering all forest types yielded an overall accuracy...

  15. Study of the effect of ionizing radiation on the structure of natural rubber latex by positron annihilation technique

    International Nuclear Information System (INIS)

    Lopez Saldana, I.R.

    1993-01-01

    At the present research, were studied the changes in natural rubber latex structure, due to electron beam by a 3 MeV, 25 m A Dynamitron electron accelerator. The natural rubber latex was irradiated at 30, 40 and 50 kGy/s dose rate, over a total dose range from 150 to 250 kGy, for each dose rate used. From natural rubber latex irradiated films were prepared by casting with 0.7 mm. thickness. In the main part, the study was made by positron annihilation lifetime (PAL), this technique is unique in the determination of free-volume properties due to the fact that positronium atom (Ps) is found to be preferentially localized in the free-volume region of polymeric materials. The positron lifetime measurements were performing using a gamma-gamma coincidence system. These results were analyzed by PATFIT-88 program computer into three components, the long-lived component for orthopositronium (o-Ps) with parameters lifetime (τ 3 ) and formation intensity (I 3 ), were plotted and analyzed for each dose rate and total dose used. Besides with τ 3 were calculated the mean free-volume size based on the spherical model for the free-volume bubble, found that the free-volume decrease slightly with the total dose due to the crosslinking of natural rubber latex. Besides was studied the effect of dose rate on tensile strength, the tensile strength is increased with the total dose although there was not a clear effect due to the dose rate. Also the films were subjected to aging in order to determined the thermal stability of natural rubber latex irradiated, the results show that the films have good stability. Besides was used the infrared spectroscopy to determine the changes due to the crosslinking by variations in the characteristically absorption bands for cis 1,4-polyisoprene. (Author)

  16. Sustainable shape memory polymers based on epoxidized natural rubber cured by zinc ferulate via oxa-Michael reaction

    Directory of Open Access Journals (Sweden)

    Xuhui Zhang

    2015-10-01

    Full Text Available Although various shape memory polymers (SMPs or diverse applications have been widely reported, the SMPs based on rubbers have been rarely realized due to the low triggering temperature of rubbers. In another aspect, the SMPs based on sustainable substances are highly desired for the growing shortage in fossil resources. In the present study, we accordingly developed the sustainable SMPs with tunable triggering temperature, based on natural rubber (NR and ferulic acid (FA as the raw materials. Specifically, the SMPs are based on a crosslinked network of epoxidized natural rubber (ENR crosslinked by in situ formed zinc ferulate (ZDF via oxa-Michael reaction. The excellent shape memory effect (SME is found in these SMPs, as evidenced by the high fixity/recovery ratio and the tunable triggering temperature. With the incorporation of natural halloysite nanotubes (HNTs, the stress and recovery rate of the SMPs are found to be tunable, which widens the application of this kind of SMPs. The combination of adoption of sustainable raw materials, and the excellent and tunable SME makes these SMPs potentially useful in many applications, such as various actuators and heat-shrinkable package materials.

  17. Trial production of low protein irradiated natural rubber latex by low energy electron beam in pilot scale

    International Nuclear Information System (INIS)

    Utama, Marga; Yoshii, F.; Kume, T.

    2006-01-01

    Three importance factors for producing low protein by low energy electron beam (250 keV/10 mA) irradiation in pilot scale (20 liters per bath) with 1,9-nonediol diacrylate (NDA) namely: maturation time of natural rubber latex before irradiation, treatment of irradiated natural rubber latex (INRL) before and after centrifugation, and standard irradiation method has been carried out. The results showed that the optimum irradiation time for producing INRL with 5 phr (part hundred ratio of rubber) of NDA as sensitize agent, and with the rotation speed of agitation 210 rpm (rotation per minutes) was between 20-30 minutes. By using this condition tensile strength of the INRL film was 26 MPa. The maturation of natural rubber latex before irradiation is the key for driving the quality of INRL. Water extractable protein content of INRL after leaching in 1% ammonia solution for 30 minutes at room temperature was around 47 μ/g, and after adding with 1 phr of PVA (poly vinyl alcohol) or 0.1 phr CMC (carboxy methyl cellulose) the water extractable protein content decrease less than 6 μ/g. (author)

  18. A Lettuce (Lactuca sativa) Homolog of Human Nogo-B Receptor Interacts with cis-Prenyltransferase and Is Necessary for Natural Rubber Biosynthesis*

    Science.gov (United States)

    Qu, Yang; Chakrabarty, Romit; Tran, Hue T.; Kwon, Eun-Joo G.; Kwon, Moonhyuk; Nguyen, Trinh-Don; Ro, Dae-Kyun

    2015-01-01

    Natural rubber (cis-1,4-polyisoprene) is an indispensable biopolymer used to manufacture diverse consumer products. Although a major source of natural rubber is the rubber tree (Hevea brasiliensis), lettuce (Lactuca sativa) is also known to synthesize natural rubber. Here, we report that an unusual cis-prenyltransferase-like 2 (CPTL2) that lacks the conserved motifs of conventional cis-prenyltransferase is required for natural rubber biosynthesis in lettuce. CPTL2, identified from the lettuce rubber particle proteome, displays homology to a human NogoB receptor and is predominantly expressed in latex. Multiple transgenic lettuces expressing CPTL2-RNAi constructs showed that a decrease of CPTL2 transcripts (3–15% CPTL2 expression relative to controls) coincided with the reduction of natural rubber as low as 5%. We also identified a conventional cis-prenyltransferase 3 (CPT3), exclusively expressed in latex. In subcellular localization studies using fluorescent proteins, cytosolic CPT3 was relocalized to endoplasmic reticulum by co-occurrence of CPTL2 in tobacco and yeast at the log phase. Furthermore, yeast two-hybrid data showed that CPTL2 and CPT3 interact. Yeast microsomes containing CPTL2/CPT3 showed enhanced synthesis of short cis-polyisoprenes, but natural rubber could not be synthesized in vitro. Intriguingly, a homologous pair CPTL1/CPT1, which displays ubiquitous expressions in lettuce, showed a potent dolichol biosynthetic activity in vitro. Taken together, our data suggest that CPTL2 is a scaffolding protein that tethers CPT3 on endoplasmic reticulum and is necessary for natural rubber biosynthesis in planta, but yeast-expressed CPTL2 and CPT3 alone could not synthesize high molecular weight natural rubber in vitro. PMID:25477521

  19. A lettuce (Lactuca sativa) homolog of human Nogo-B receptor interacts with cis-prenyltransferase and is necessary for natural rubber biosynthesis.

    Science.gov (United States)

    Qu, Yang; Chakrabarty, Romit; Tran, Hue T; Kwon, Eun-Joo G; Kwon, Moonhyuk; Nguyen, Trinh-Don; Ro, Dae-Kyun

    2015-01-23

    Natural rubber (cis-1,4-polyisoprene) is an indispensable biopolymer used to manufacture diverse consumer products. Although a major source of natural rubber is the rubber tree (Hevea brasiliensis), lettuce (Lactuca sativa) is also known to synthesize natural rubber. Here, we report that an unusual cis-prenyltransferase-like 2 (CPTL2) that lacks the conserved motifs of conventional cis-prenyltransferase is required for natural rubber biosynthesis in lettuce. CPTL2, identified from the lettuce rubber particle proteome, displays homology to a human NogoB receptor and is predominantly expressed in latex. Multiple transgenic lettuces expressing CPTL2-RNAi constructs showed that a decrease of CPTL2 transcripts (3-15% CPTL2 expression relative to controls) coincided with the reduction of natural rubber as low as 5%. We also identified a conventional cis-prenyltransferase 3 (CPT3), exclusively expressed in latex. In subcellular localization studies using fluorescent proteins, cytosolic CPT3 was relocalized to endoplasmic reticulum by co-occurrence of CPTL2 in tobacco and yeast at the log phase. Furthermore, yeast two-hybrid data showed that CPTL2 and CPT3 interact. Yeast microsomes containing CPTL2/CPT3 showed enhanced synthesis of short cis-polyisoprenes, but natural rubber could not be synthesized in vitro. Intriguingly, a homologous pair CPTL1/CPT1, which displays ubiquitous expressions in lettuce, showed a potent dolichol biosynthetic activity in vitro. Taken together, our data suggest that CPTL2 is a scaffolding protein that tethers CPT3 on endoplasmic reticulum and is necessary for natural rubber biosynthesis in planta, but yeast-expressed CPTL2 and CPT3 alone could not synthesize high molecular weight natural rubber in vitro. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  20. THE EFFLUENT OF NATURAL-RUBBER FACTORIES IS ENRICHED IN THE ANTIFUNGAL PROTEIN HEVEIN

    NARCIS (Netherlands)

    SOEDJANAATMADJA, UMS; SUBROTO, T; BEINTEMA, JJ

    1995-01-01

    Hevein is a small cystine-rich protein with a polypeptide chain length of 43 residues. It occurs in the lutoid body fraction of rubber latex, has affinity for chitin, and inhibits fungal growth. It was isolated from the effluent of a rubber factory in a yield of about 0.7 g/l. The elution position

  1. Natural-draught cooling towers made of reinforced concrete

    International Nuclear Information System (INIS)

    Kraetzig, W.B.; Peters, H.L.; Zerna, W.

    1978-01-01

    Large power plant units and dry cooling tower technology require larger dimensions for natural-draught cooling towers. The main curvation radii in latitudinal and meridian direction are thus increased, which results in a lower three-dimensional support strength. This development is an incentive for constant re-consideration of calculation methods, safety philosophy, and dimensioning criteria. In this context, wind effects have been re-formulated and given a scientific foundation. Constructional measures to improve the static and dynamic behaviour of the structure have been presented and critically assessed. A cost analysis, finally, gave the most rational applications of the new shell construction with reinforcing elements. A cooling tower now under construction gave a realistic example. Fundamental aspects concerning the foundations of cooling tower shells and two special types of foundation are further points to clarify the subject. (orig./HP) [de

  2. Mapping Rubber Plantations and Natural Forests in Xishuangbanna (Southwest China Using Multi-Spectral Phenological Metrics from MODIS Time Series

    Directory of Open Access Journals (Sweden)

    Sebastian van der Linden

    2013-05-01

    Full Text Available We developed and evaluated a new approach for mapping rubber plantations and natural forests in one of Southeast Asia’s biodiversity hot spots, Xishuangbanna in China. We used a one-year annual time series of Moderate Resolution Imaging Spectroradiometer (MODIS, Enhanced Vegetation Index (EVI and short-wave infrared (SWIR reflectance data to develop phenological metrics. These phenological metrics were used to classify rubber plantations and forests with the Random Forest classification algorithm. We evaluated which key phenological characteristics were important to discriminate rubber plantations and natural forests by estimating the influence of each metric on the classification accuracy. As a benchmark, we compared the best classification with a classification based on the full, fitted time series data. Overall classification accuracies derived from EVI and SWIR time series alone were 64.4% and 67.9%, respectively. Combining the phenological metrics from EVI and SWIR time series improved the accuracy to 73.5%. Using the full, smoothed time series data instead of metrics derived from the time series improved the overall accuracy only slightly (1.3%, indicating that the phenological metrics were sufficient to explain the seasonal changes captured by the MODIS time series. The results demonstrate a promising utility of phenological metrics for mapping and monitoring rubber expansion with MODIS.

  3. Enhancing the thermal stability of natural rubber/recycled ethylene–propylene–diene rubber blends by means of introducing pre-vulcanised ethylene–propylene–diene rubber and electron beam irradiation

    International Nuclear Information System (INIS)

    Nabil, H.; Ismail, H.

    2014-01-01

    Highlights: • New route of processing was introduced to optimise the thermal stability of NR/R-EPDM blends. • Pre-vulcanised EPDM and EB irradiation were introduced into NR/R-EPDM blends. • Thermal stability is obviously enhanced by applying these two techniques. • Applying new route of processing methods is clearly successful to NR/R-EPDM blends. - Abstract: Most rubber materials are subjected to oxidation. The rate of oxidation depends on the type of rubber, processing method, and end-use conditions. The oxidation of rubber can result in the loss of physical properties, such as tensile strength, elongation, and flexibility. Hence, the service life is determined by oxidation stability. Thermal properties are relevant to the potential use of polymeric materials in many consumer oriented applications. Thermo-oxidative ageing and thermogravimetric analysis (TGA) have been proven to be successful techniques in determining the thermal stability of polymers and polymer blends. In this article, preparation of a series of natural rubber/recycled ethylene–propylene–diene rubber (NR/R-EPDM) blends is described. Processing of the blends, by means of introducing pre-vulcanised EPDM and electron beam (EB) irradiation, was carried out. Two thermal analysis methods, namely thermo-oxidative ageing and thermogravimetric analysis, were conducted. The results indicated that pre-vulcanising EPDM for 1.45 min (ts − 2) is sufficient to gain the optimum retained tensile and elongation at break. It was simultaneously observed that the introduction of pre-vulcanised EPDM increased decomposition temperature and activation energy by showing optimum values at a pre-vulcanising time of 3.45 min (ts). In the latter study, the retained properties increased after EB irradiation. The results can be verified by the thermal decomposition temperature and their activation energy. The obtained TG profiles and the calculated kinetic parameters indicated that introducing EB irradiation

  4. Ballistic Performance of Mallow and Jute Natural Fabrics Reinforced Epoxy Composites in Multilayered Armor

    OpenAIRE

    Nascimento, Lucio Fabio Cassiano; Louro, Luis Henrique Leme; Monteiro, Sergio Neves; Gomes, Alaelson Vieira; Marçal, Rubens Lincoln Santana Blazutti; Lima Júnior, Édio Pereira; Margem, Jean Igor

    2017-01-01

    Natural fiber reinforced polymer composites have recently been investigated as a component of multilayered armor system (MAS). These composites were found to present advantages when replacing conventional high strength synthetic aramid fabric laminate composite (KevlarTM, with same thickness, as MAS second layer. Continuous and loose natural fibers were up to now mostly used to reinforce these ballistic composites. Only two natural fabrics reinforced polymer composite were so far used with sa...

  5. Mechanical Properties and Morphological Characterization of PLA/Chitosan/Epoxidized Natural Rubber Composites

    Directory of Open Access Journals (Sweden)

    Zainoha Zakaria

    2013-01-01

    Full Text Available Poly (lactic acid (PLA/chitosan (CS natural polymer/epoxidised natural rubber (ENR composites were successfully prepared through a solution casting method. The morphological characteristics of fabricated composites were investigated by scanning electron microscopy (SEM and optical microscopy. The microstructure of PLA/ENR was significantly altered with the addition of CS. SEM analysis of composites fractured surfaces revealed smooth and homogeneous texture and good dispersion of CS. However for 15 wt% CS composites, the phase segregation and poor adhesion between the polymers were observed. Fourier transform infrared spectroscopy revealed some levels of attractive interaction between CS, PLA, and ENR in the composites. The mechanical properties of composites in terms of tensile strength and tensile modulus were significantly improved with the addition of CS into the matrix while the percent elongation at break decreased. The tensile strength increased up to 5 wt% CS loading for both PLA/CS and PLA/ENR/CS and thereafter decreased while Young’s modulus increased up to 10 wt%. However, when the CS content was increased to 15 wt%, the tensile strength and tensile modulus were slightly decreased. These improvements were attributed to good dispersion of CS at the optimum filler levels and attractive interaction between the composites components.

  6. The Effect of Minarex B Oil and Gamma Irradiation on the Mechanical Properties of Vulcanized Natural Rubber-LDPE Mixture for Shoe Sole

    International Nuclear Information System (INIS)

    Sudradjat Iskandar; Isni Marliyanti

    2004-01-01

    To obtain the optimum concentration of minarex B oil and gamma irradiation dose on natural rubber compound for shoe sole, study on the effect of minarex B oil and gamma radiation on the mechanical properties of vulcanized natural rubber-LDPE mixture has been done. Natural rubber was masticated and mixed with additive and filler using two-roll machine, at 120 o C of forward roll and 100 o C of backward roll, with rotation speed of 18 rpm. The additives added with irganox 1076, paraffin wax, stearic acid, and minarex B oil, while fillers used were polyethylene (LDPE) and calcium carbonate. Minarex B oil mixed was vary such as 5, 10 and 20 phr (part per hundred of rubber). The amount of filler and other additives mixed was not varied. The natural rubber film was obtained by pressing the mixture using hot and cold press machine at 135 o C and room temperature for about 3 minutes. The film then irradiated with gamma rays from cobalt-60 source, at the doses of 150, 300, and 500 kGy. The results show that the mechanical properties of natural rubber vulcanized decreases by increasing minarex B oil, and increases by increasing of irradiation dose. The concentration optimum of minarex B oil in the natural rubber compound for shoe sole and irradiation dose about 5 phr and 300 kGy were agree with SII 0944-84. (author)

  7. The partial replacement of palm kernel shell by carbon black and halloysite nanotubes as fillers in natural rubber composites

    Science.gov (United States)

    Daud, Shuhairiah; Ismail, Hanafi; Bakar, Azhar Abu

    2017-07-01

    The effect of partial replacement of palm kernel shell powder by carbon black (CB) and halloysite nanotube (HNT) on the tensile properties, rubber-filler interaction, thermal properties and morphological studies of natural rubber (NR) composites were investigated. Four different compositions of NR/PKS/CB and NR/PKS/HNT composites i.e 20/0, 15/5, 10/10,5/15 and 0/20 parts per hundred rubber (phr) were prepared on a two roll mill. The results showed that the tensile strength and modulus at 100% elongation (M100) and 300% elongation (M300) were higher for NR/PKS/CB compared to NR/PKS/HNT composites. NR/PKS/CB composites had the lowest elongation at break (Eb). The effect of commercial fillers in NR/PKS composites on tensile properties was confirmed by the rubber-filler interaction and scanning electron microscopy (SEM) study. The thermal stability of PKS filled NR composites with partially replaced by commercial fillers also determined by Thermo gravimetric Analysis (TGA).

  8. Technical - economical opportunity of replacing rubber coated steel in tubes and reinforcements by polyethylene of high density for corrosive media

    International Nuclear Information System (INIS)

    Alessandrescu, A.; Dogaru, D.

    2004-01-01

    The polyethylene of high density, PEHD, is currently used for methane gas, drinking water (hot and cool) tube systems as well as for interior and exterior installations for domestic and industrial consumers. In this paper one proposes an extension of the range of PEHD utilizations to irrigation grids, transport and distribution of the food and industrial liquids, for coating the optical fibres, replacing the systems of tubes with anti corrosive properties (stainless steels, carbon steels coated with rubber), protection of hot fluid transport tubes, fire extinguishers, etc.). To evidence the advantages of replacing the rubber coated steel tubing by PEHD tubes a comparative technical-economical thorough analysis was conducted in the Heavy Water Plant . The paper presents: - the PEHD, a thermoplastic material for fluid transport under pressure; - physico-chemical and mechanical properties of the PEHD products; - types of characteristic dimensions of the PEHD products; - techniques of joining used in mounting PEHD grids; - tools and devices used in welding. Presented are the general properties and computing elements for tubes, assembling procedures, testing and quality control in the mountings of PEHD tube systems. In conclusion, using PEHD in the fields mentioned is advantageous from both technical and economical point of view as compared with rubber coated tubing

  9. Mechanical Properties of Medium Density Fibreboard Composites Material Using Recycled Rubber and Coconut Coir

    OpenAIRE

    S. Mahzan; A.M. Ahmad Zaidi; M.I. Ghazali; N. Arsat; M.N. M. Hatta

    2010-01-01

    Natural fibre reinforced composite has emerged as highly potential replacement for synthetic fibres. Various natural waste fibres have been adopted for various engineering applications. This paper investigates the mechanical properties of medium density fibreboard composites material fabricated using recycled rubber and coconut coir. The suitability of using recycled rubber and coconut coir as a raw material and polyurethane as a resin in the manufacturer of medium density fibreboard was also...

  10. Estimating the concentration of gold nanoparticles incorporated on natural rubber membranes using multi-level starlet optimal segmentation

    Energy Technology Data Exchange (ETDEWEB)

    Siqueira, A. F. de, E-mail: siqueiraaf@gmail.com; Cabrera, F. C., E-mail: flavioccabrera@yahoo.com.br [UNESP – Univ Estadual Paulista, Dep de Física, Química e Biologia (Brazil); Pagamisse, A., E-mail: aylton@fct.unesp.br [UNESP – Univ Estadual Paulista, Dep de Matemática e Computação (Brazil); Job, A. E., E-mail: job@fct.unesp.br [UNESP – Univ Estadual Paulista, Dep de Física, Química e Biologia (Brazil)

    2014-12-15

    This study consolidates multi-level starlet segmentation (MLSS) and multi-level starlet optimal segmentation (MLSOS) techniques for photomicrograph segmentation, based on starlet wavelet detail levels to separate areas of interest in an input image. Several segmentation levels can be obtained using MLSS; after that, Matthews correlation coefficient is used to choose an optimal segmentation level, giving rise to MLSOS. In this paper, MLSOS is employed to estimate the concentration of gold nanoparticles with diameter around 47  nm, reduced on natural rubber membranes. These samples were used for the construction of SERS/SERRS substrates and in the study of the influence of natural rubber membranes with incorporated gold nanoparticles on the physiology of Leishmania braziliensis. Precision, recall, and accuracy are used to evaluate the segmentation performance, and MLSOS presents an accuracy greater than 88 % for this application.

  11. Multifunctional Peroxidegas Alternative Crosslink Agents for Dynamically Vulcanized Expoxidized Natural Rubber/Polypropylene Blends

    NARCIS (Netherlands)

    Thitithammawong, A.; Thitithammawong, A.; Sahakaro, Kannika; Noordermeer, Jacobus W.M.

    2009-01-01

    Commonly used dicumyl peroxide (DCP) in combination with coagent, triallyl cyanurate (TAC), as a crosslinking agent is well acceptable for dynamically vulcanized rubber phase of thermoplastic vulcanizates (TPVs). However, it generally produces volatile decomposition products, which cause a typical

  12. Investigation of miscibility of p(3hydroxybutyrate-co-3hydroxyhexanoate) and epoxidized natural rubber blends

    Energy Technology Data Exchange (ETDEWEB)

    Akram, Faridah; Chan, Chin Han; Natarajan, Valliyappan David [Faculty of Applied Sciences, Universiti Teknologi MARA, Shah Alam, 40450 Selangor Darul Ehsan (Malaysia)

    2015-08-28

    Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate [P(3HB-co-3HHx)] produced by C. necator PHB{sup −}4 harboring phaC{sub cs} from crude palm kernel oil with 21 mol% of 3-hydroxyhexanoate and epoxidized natural rubber with 25 mol% of epoxy content (ENR-25) were used to study the miscibility of the blends by attenuated total reflection-Fourier transform infrared (ATR-FTIR) and differential scanning calorimetry (DSC). The polymers used were purified and the blends were prepared by solution casting method. Nuclear magnetic resonance (NMR) spectra confirm the purity and molecular structures of P(3HB-co-3HHx) and ENR-25. FTIR spectra for different compositions of P(3HB-co-3HHx) and ENR-25 blends show absorbance change of the absorbance bands but with no significant shifting of the absorbance bands as the P(3HB-co-3HHx) content decreases, which shows that there is no intermolecular interaction between the parent polymer blends. On top of that, there are two T{sub g}s present for the blends and both remain constant for different compositions which corresponds to the T{sub g}s of the parent polymers. This indicates that the blends are immiscible.

  13. Engineering characterisation of epoxidized natural rubber-modified hot-mix asphalt.

    Directory of Open Access Journals (Sweden)

    Ramez A Al-Mansob

    Full Text Available Road distress results in high maintenance costs. However, increased understandings of asphalt behaviour and properties coupled with technological developments have allowed paving technologists to examine the benefits of introducing additives and modifiers. As a result, polymers have become extremely popular as modifiers to improve the performance of the asphalt mix. This study investigates the performance characteristics of epoxidized natural rubber (ENR-modified hot-mix asphalt. Tests were conducted using ENR-asphalt mixes prepared using the wet process. Mechanical testing on the ENR-asphalt mixes showed that the resilient modulus of the mixes was greatly affected by testing temperature and frequency. On the other hand, although rutting performance decreased at high temperatures because of the increased elasticity of the ENR-asphalt mixes, fatigue performance improved at intermediate temperatures as compared to the base mix. However, durability tests indicated that the ENR-asphalt mixes were slightly susceptible to the presence of moisture. In conclusion, the performance of asphalt pavement can be enhanced by incorporating ENR as a modifier to counter major road distress.

  14. Transdermal nicotine mixed natural rubber-hydroxypropylmethylcellulose film forming systems for smoking cessation: in vitro evaluations.

    Science.gov (United States)

    Pichayakorn, Wiwat; Suksaeree, Jirapornchai; Boonme, Prapaporn; Taweepreda, Wirach; Amnuaikit, Thanaporn; Ritthidej, Garnpimol C

    2014-08-27

    Abstract Novel film forming polymeric dispersions for transdermal nicotine delivery were prepared from deproteinized natural rubber latex (DNRL) blended with hydroxypropylmethylcellulose (HPMC) and dibutyl phthalate (DBP) or glycerin (GLY) as plasticizer. The preliminary molecular compatibility of ingredients was observed by Fourier transform infrared spectroscopy, differential scanning calorimetry and X-ray diffractometry characterizations. All film forming polymeric dispersions were elegant in appearance and smooth in texture without agglomeration. Their pH was 7-8. In addition, their viscosity and spreadability showed good characteristics depended on HPMC and plasticizers blended. The transparent in situ dry films with good strength and elasticity were also confirmed by peeling-off. The nicotine release from them revealed an initial fast release that was similar to the release from a concentrated nicotine solution, and followed by slow release pattern from the in situ films. GLY blended formulation produced a higher amount of nicotine permeation through the in vitro pig skin than DBP blends. Ethanol mixing also enhanced nicotine permeation, but it affected the integrity of in situ films. The nicotine release and skin permeation kinetics were by a diffusion mechanism that was confirmed by the Higuchi's model. These formulations were safe without producing any severe skin irritation. However, for the stability they needed to be stored at 4 °C in tightly sealed containers.

  15. Investigation of miscibility of p(3hydroxybutyrate-co-3hydroxyhexanoate) and epoxidized natural rubber blends

    International Nuclear Information System (INIS)

    Akram, Faridah; Chan, Chin Han; Natarajan, Valliyappan David

    2015-01-01

    Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate [P(3HB-co-3HHx)] produced by C. necator PHB − 4 harboring phaC cs from crude palm kernel oil with 21 mol% of 3-hydroxyhexanoate and epoxidized natural rubber with 25 mol% of epoxy content (ENR-25) were used to study the miscibility of the blends by attenuated total reflection-Fourier transform infrared (ATR-FTIR) and differential scanning calorimetry (DSC). The polymers used were purified and the blends were prepared by solution casting method. Nuclear magnetic resonance (NMR) spectra confirm the purity and molecular structures of P(3HB-co-3HHx) and ENR-25. FTIR spectra for different compositions of P(3HB-co-3HHx) and ENR-25 blends show absorbance change of the absorbance bands but with no significant shifting of the absorbance bands as the P(3HB-co-3HHx) content decreases, which shows that there is no intermolecular interaction between the parent polymer blends. On top of that, there are two T g s present for the blends and both remain constant for different compositions which corresponds to the T g s of the parent polymers. This indicates that the blends are immiscible

  16. Investigation of miscibility of p(3hydroxybutyrate-co-3hydroxyhexanoate) and epoxidized natural rubber blends

    Science.gov (United States)

    Akram, Faridah; Chan, Chin Han; Natarajan, Valliyappan David

    2015-08-01

    Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate [P(3HB-co-3HHx)] produced by C. necator PHB-4 harboring phaCcs from crude palm kernel oil with 21 mol% of 3-hydroxyhexanoate and epoxidized natural rubber with 25 mol% of epoxy content (ENR-25) were used to study the miscibility of the blends by attenuated total reflection-Fourier transform infrared (ATR-FTIR) and differential scanning calorimetry (DSC). The polymers used were purified and the blends were prepared by solution casting method. Nuclear magnetic resonance (NMR) spectra confirm the purity and molecular structures of P(3HB-co-3HHx) and ENR-25. FTIR spectra for different compositions of P(3HB-co-3HHx) and ENR-25 blends show absorbance change of the absorbance bands but with no significant shifting of the absorbance bands as the P(3HB-co-3HHx) content decreases, which shows that there is no intermolecular interaction between the parent polymer blends. On top of that, there are two Tgs present for the blends and both remain constant for different compositions which corresponds to the Tgs of the parent polymers. This indicates that the blends are immiscible.

  17. Preparation and structural characterization of vulcanized natural rubber nanocomposites containing nickel-zinc ferrite nanopowders.

    Science.gov (United States)

    Bellucci, F S; Salmazo, L O; Budemberg, E R; da Silva, M R; Rodríguez-Pérez, M A; Nobre, M A L; Job, A E

    2012-03-01

    Single-phase polycrystalline mixed nickel-zinc ferrites belonging to Ni0.5Zn0.5Fe2O4 were prepared on a nanometric scale (mean crystallite size equal to 14.7 nm) by chemical synthesis named the modified poliol method. Ferrite nanopowder was then incorporated into a natural rubber matrix producing nanocomposites. The samples were investigated by means of infrared spectroscopy, X-ray diffraction, scanning electron microscopy and magnetic measurements. The obtained results suggest that the base concentration of nickel-zinc ferrite nanoparticles inside the polymer matrix volume greatly influences the magnetic properties of nanocomposites. A small quantity of nanoparticles, less than 10 phr, in the nanocomposite is sufficient to produce a small alteration in the semi-crystallinity of nanocomposites observed by X-ray diffraction analysis and it produces a flexible magnetic composite material with a saturation magnetization, a coercivity field and an initial magnetic permeability equal to 3.08 emu/g, 99.22 Oe and 9.42 x 10(-5) respectively.

  18. Evaluation of permanent deformation and durability of epoxidized natural rubber modified asphalt mix

    Science.gov (United States)

    Al-Mansob, Ramez A.; Ismail, Amiruddin; Rahmat, Riza Atiq O. K.; Nazri Borhan, Muhamad; Alsharef, Jamal M. A.; Albrka, Shaban Ismael; Rehan Karim, Mohamed

    2017-09-01

    The road distresses have caused too much in maintenance cost. However, better understandings of the behaviours and properties of asphalt, couples with greater development in technology, have allowed paving technologists to examine the benefits of introducing additives and modifiers. As a result, modifiers such as polymers are the most popular modifiers used to improve the performance of asphalt mix. This study was conducted to investigate the use of epoxidized natural rubber (ENR) to be mixed with asphalt mix. Tests were conducted to investigate the performance characteristics of ENR-asphalt mixes, where the mixes were prepared according to the wet process. Mechanical testing on the ENR-asphalt mixes have demonstrated that the asphalt mix permanent deformation performance at high temperature was found to be improved compared to the base mixes. However, the durability studies have indicated that ENR-asphalt mixes are slightly susceptible with the presence of moisture. The durability of the ENR-asphalt mixes were found to be enhanced in term of permanent deformation at high and intermediate temperatures compared to the base asphalt mixes. As conclusion, asphalt pavement performance can be enhanced by using ENR as modifier to face the major road distresses.

  19. Characterization of Mechanical Properties of Marble sludge/natural rubber composites

    International Nuclear Information System (INIS)

    Bhatti, K.P.

    2012-01-01

    This study aims to investigate the possible utilization of Marble Sludge (MS) in Natural Rubber (NR) composites, which would reduce both the environmental pollution and product cost. Marble waste in the form of sludge is taken from Mangopir Marble industrial area Karachi. The sludge was dried, grinded and passed through desire sieves (20, 37 and 75 micro m) and incorporated in the formulation of NR composites. The physical characteristics of dry MS were carried out in order to identify all components by instrumental techniques. Different micro sized particles of MS (20, 37 and 75 micro-m) were added with different loading (10, 30, 50, 70 and 90 phr). Mechanical properties of MS filled NR composites were studied. It was found that tensile strength and tear strength increased with increasing the MS till 70 phr. Further addition of MS in the composites decreased both strengths. Elongation at break and rebound resilience decreased with increasing MS loading, while modulus, (100%, 200% and 300% elongation), hardness, compression set and abrasion loss increased with increase loading of MS. All mechanical properties of smaller micro size MS particle (20 micro-m) filled NR composites have higher values then 37 and 75 micro-m size particle. The results of mechanical properties after aging show that the tensile strength, modulus, elongation at break and rebound resilience values decreased while hardness, compression set and abrasion loss values increased. (author)

  20. Effect of sucrose acetate isobutyrate ester on the epoxidised natural rubber based magnetorheological elastomers

    International Nuclear Information System (INIS)

    Khairi, M. H. A; Mazlan, S. A.; Aziz, S. A. A.; Yunus, N. A.; Ubaidillah; Ahmad, K. Z. K.

    2016-01-01

    In this study, magnetorheological elastomers (MREs) were synthesized by incorporating various amounts of sucrose acetate isobutyrate (SAIB) ester plasticizer dopped in the epoxidized natural rubber (ENR-50) matrix with constant carbonyl iron particles (CIPs) of 60 weight percent. The effect of SAIB insertion on curing characteristics has been observed using a moving die rheometer. The microstructures appearance of the samples were observed using a field emission scanning electron microscope (FESEM). Finally, the magneto-induced storage modulus was measured by using a rheometer 302. The experimental results have demonstrated that the addition of SAIB ester decreased the cure rate index (CRI) by 63% and increased the MR effect by 37%. Observation of microstructure shows that the CIPs embedded well in the matrix and produced the isotropic structure of the MREs. Meanwhile, the fabricated MREs samples were frequencies dependent, where all MREs samples exhibit the incremental trend when increasing the frequencies. The introduction of SAIB has proven to influence the properties of the MREs. (paper)

  1. Exfoliation approach for preparing high conductive reduced graphite oxide and its application in natural rubber composites

    Energy Technology Data Exchange (ETDEWEB)

    Wipatkrut, Pattharaporn [Department of Chemical Technology, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Poompradub, Sirilux, E-mail: sirilux.p@chula.ac.th [Department of Chemical Technology, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Center for Petroleum, Petrochemical and Advanced Material, Chulalongkorn University, Bangkok 10330 (Thailand)

    2017-04-15

    Highlights: • Graphite waste was exfoliated by oxidation and chemical and thermal reduction. • The obtained graphene-T was a single layer sheet with a high electrical conductivity. • Graphene-T incorporation at 5 phr improved the electrical conductivity of NR. • Graphene-T incorporation at 5–25 phr improved the mechanical properties of NR. - Abstract: High conductivity reduced graphite oxide (RGO) was prepared by exfoliation of graphite waste from the metal smelting industry. To improve the surface properties of the RGO, the graphite oxide obtained based on Hummers’ method was reduced by L-ascorbic acid to give RGOV, which was then subjected to thermal reduction to obtain RGOT. The residual oxygen-containing groups in RGOV were almost completely removed by the thermal reduction and the conjugated graphene networks were restored in RGOT. The effect of the RGOT content in natural rubber (NR) on the cure, electrical and mechanical properties of the NR-RGOT (NG) composites was evaluated. The electrical conductivity of NR was increased by the inclusion of RGOT at a percolation threshold of 5 phr, with an electrical conductivity of 8.71 × 10{sup −6} S/m. The mechanical properties, i.e., the modulus, tensile strength and hardness, of NG were comparable with those of conductive carbon black filled NR ones.

  2. Radiation vulcanization of natural rubber latex with low energy accelerator-II

    Energy Technology Data Exchange (ETDEWEB)

    Haque, Md. Emdadul; Makuuchi, Keizo; Ikeda, Kenichi; Yoshii, Fumio; Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Mitomo, Hiroshi [Gunma Univ., Faculty of Engineering, Dept. of Biological and Chemical Engineering, Kiryu, Gunma (Japan)

    2002-03-01

    The natural rubber latex (NRL) was radiation vulcanized under a low energy electron accelerator. Accelerating voltage and maximum beam current of this accelerator are 250 kV and 10 mA respectively. Irradiation was carried out in a reaction vessel with constant stirring. The capacity of the vessel is 18 liters. Radiation vulcanization accelerators (RVA) were normal butyl acrylate (n-BA) and nonane-diol-diacrylate (NDDA). NDDA has no bad smell like that of n-BA. 20 minutes irradiation time is enough to vulcanize 14 liters of latex when 5 phr RVA (both types) are used. Maximum of {approx}30 MPa tensile strength was obtained with 5 phr NDD-A. However the remained NDDA is difficult to remove due to high molecular weight. Water-extractable proteins content was determined in dipped films for various leaching conditions without and with additive (polyvinyl alcohol, PVA). Water extractable proteins content is reduced to {<=} 41 by adding 5 phr PVA and leaching for 8 hours. The tackiness of the dipped films is reduced to 0.1 from 9 gf by mixing 6 phr PVA with the irradiated latex. Hand gloves (surgical and examination) were successfully produced from the irradiated latex. (author)

  3. Content of Asthmagen Natural Rubber Latex Allergens in Commercial Disposable Gloves.

    Science.gov (United States)

    Bittner, C; Garrido, M V; Krach, L H; Harth, V

    The use of natural rubber latex (NRL) gloves in many occupations may lead to latex sensitization, allergic asthma, and skin reactions. Due to their good properties and environmental safety NRL gloves are still being used in the healthcare setting, but also in the food industry, by hairdressers, cleaners, etc. The aim of our study was to assess the protein and NRL allergen content in commercial gloves by different methods, including a new assay. Twenty commercially available NRL gloves were analyzed. Protein extraction was performed according to the international standard ASTM D-5712. Total protein content was measured with a modified Lowry method, NRL content with the CAP Inhibition Assay, the Beezhold ELISA Inhibition Assay, and an innovative ELISA with IgY-antibodies extracted from eggs of NRL-immunized hens (IgY Inhibition Assay). We found a high protein content in a range of 215.0-1304.7 μg/g in 8 out of the 20 NRL gloves. Seven of the 20 gloves were powdered, four of them with a high protein content. In gloves with high protein content, the immunological tests detected congruently high levels of NRL allergen. We conclude that a high percentage of commercially available NRL gloves still represent a risk for NRL allergy, including asthma. The modified Lowry Method allows to infer on the latex allergen content.

  4. Natural rubber latex used as drug delivery system in guided bone regeneration (GBR

    Directory of Open Access Journals (Sweden)

    Rondinelli Donizetti Herculano

    2009-06-01

    Full Text Available In this work, we propose natural rubber latex (NRL membranes as a protein delivery system. For this purpose Bovine Serum Albumin (BSA was incorporated into the latex solution for in vitro protein delivery experiments. Different polymerization temperatures were used, from -10 to 27 °C, in order to control the membrane morphology. These membranes were characterized by Scanning Electron Microscopy (SEM, Atomic Force Microscopy (AFM, as well as the Lowry Method to measure the BSA release. SEM and AFM microscopy analysis showed that the number, size and distribution of pores in NRL membranes can be varied, as well as its overall morphology. We have found that the morphology of the membrane is the predominant factor for higher protein release, compared with pore size and number of pores. Results demonstrated that the best drug-delivery system was the membrane polymerized at RT (27 °C, which does release 66% of its BSA content for up to 18 days. Our results indicate that NRLb could be used in the future as an active membrane that could accelerate bone healing in GBR.

  5. Neutron shielding behavior of thermoplastic natural rubber/boron carbide composites

    Science.gov (United States)

    Mat Zali, Nurazila; Yazid, Hafizal; Megat Ahmad, Megat Harun Al Rashid

    2018-01-01

    Many shielding materials have been designed against the harm of different types of radiation to the human body. Today, polymer-based lightweight composites have been chosen by the radiation protection industry. In the present study, thermoplastic natural rubber (TPNR) composites with different weight percent of boron carbide (B4C) fillers (0% to 30%) were fabricated as neutron shielding through melt blending method. Neutron attenuation properties of TPNR/B4C composites have been investigated. The macroscopic cross section (Σ), half value layer (HVL) and mean free path length (λ) of the composites have been calculated and the transmission curves have been plotted. The obtained results show that Σ, HVL and λ greatly depend on the B4C content. Addition of B4C fillers into TPNR matrix were found to enhance the macroscopic cross section values thus decrease the mean free path length (λ) and half value layer (HVL) of the composites. The transmission curves exhibited that the neutron transmission of the composites decreased with increasing shielding thickness. These results showed that TPNR/B4C composites have high potential for neutron shielding applications.

  6. Polymer Gel Electrolytes Based on 49 % Methyl-Grafted Natural Rubber

    International Nuclear Information System (INIS)

    Kamisan, A.S.; Kudin, T.I.T.; Ali, A.M.M.; Yahya, M.Z.A.; Yahya, M.Z.A.

    2011-01-01

    Polymer gel electrolytes (PGEs) based on 49 % methyl-grafted natural rubber (MG49) were first prepared by dissolving ammonium triflate (NH 4 CF 3 SO 3 ) in propylene carbonate (PC) by various molar concentrations of NH 4 CF 3 SO 3 to obtain liquid electrolytes and were characterized by AC electrical impedance spectroscopy (EIS) measurements to study their conducting behaviour. The liquid electrolyte with optimum conductivity (0.7 M) was then gelled with MG49 and their conductivity was also studied. The highest conductivity of liquid electrolyte was 3.6 x 10 -3 Scm -1 and 2.9x10 -2 Scm -1 for PGEs. The molecular interactions between components of NH 4 CF 3 SO 3 , PC, and MG49 have been observed by ATR-FTIR spectroscopy study. The downshifting of C=O stretching frequency of PC from 1785 cm -1 to 1780 cm -1 and NH 4+ band from 1634 cm -1 to 1626 cm -1 that has been obtained by spectroscopic data in addition of NH 4 CF 3 SO 3 confirmed the complexation occurrence. Interaction between NH 4 CF 3 SO 3 and MG49 has also been investigated. This study is focused on the interactions between components in the PGE system and relates them with their conducting behavior. (author)

  7. Morphological Study on Room-Temperature-Cured PMMA-Grafted Natural Rubber-Toughened Epoxy/Layered Silicate Nanocomposite

    OpenAIRE

    Yuhana, N. Y.; Ahmad, S.; Kamal, M. R.; Jana, S. C.; Bahri, A. R. Shamsul

    2012-01-01

    A morphological study was conducted on ternary systems containing epoxy, PMMA-grafted natural rubber, and organic chemically modified montmorillonite (Cloisite 30B). Optical microscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and wide-angle X-ray diffraction (WAXD) analysis were used. The following four materials were prepared at room temperature: cured unmodified epoxy, cured toughened epoxy, cured unmodified epoxy/Cloisite 3...

  8. The effects of gamma radiation and electron beam on the mechanical properties of polypropylene dominant natural rubber blend

    International Nuclear Information System (INIS)

    Mar Mar Oo; Khairul Zaman; Tin Hlaing

    2001-01-01

    The effects of irradiation, with dose ranging from 20 to 100 kGy on the mechanical properties of polypropylene and natural rubber blends (PP/NR blends) were investigated. Crosslinking of the PP/NR blends proved to play a major role in the improvement of the mechanical properties of the blend. The results also revealed that the blend composition the enhancement in properties depend on the irradiation dose and on the concentration of the crosslinking agent. (author)

  9. Observation of immobile regions in natural rubber at ambient temperature by solid-state C-13 CP/MAS NMR spectroscopy

    DEFF Research Database (Denmark)

    Larsen, F.H.; Rasmussen, T.; Pedersen, Walther Batsberg

    1999-01-01

    Employing C-13 CP/MAS NMR spectroscopy, the existence of immobile regions in natural rubber (cis-1,4-polyisoprene) corresponding to a few percent of the monomer units has been detected at ambient temperature. For synthetic rubbers no immobile regions have been detected at all. Applying different...... physical and chemical treatments to natural rubber it is shown that mastication, gamma-irradiation, and increasing the temperature, slightly above the ambient, reduce the amount of immobile regions. (C) 1999 Elsevier Science Ltd. All rights reserved....

  10. How edge-reinforced random walk arises naturally

    NARCIS (Netherlands)

    Rolles, S.W.W.

    2003-01-01

    We give a characterization of a modified edge-reinforced random walk in terms of certain partially exchangeable sequences. In particular, we obtain a characterization of an edge-reinforced random walk (introduced by Coppersmith and Diaconis) on a 2-edge-connected graph. Modifying the notion of

  11. Ultraviolet curing of epoxidised palm oil acrylate (Epola) and liquid epoxidised natural rubber acrylate (Lenra) on rubberwood substrates-a preliminary study

    International Nuclear Information System (INIS)

    Mohd Hilmi bin Mahmood; Dahlan bin Hj Mohd; Abdul Ghani bin Harun; Ahmad Shakri bin Mat Seman; Azizol bin Abdul Kadir

    1992-01-01

    Palm oil based and natural rubber based formulations were cured by ultraviolet (UV) radiation using rubberwood as a substrate. The appearance properties of the cured films were assessed and subjected to mechanical testing. Both formulations gave good finish films. Mechanical tests show that both films can resist abrasion, heat as well as chemical. Overall results show that natural rubber based formulation is superior than palm oil based

  12. Development of natural fiber reinforced polylactide-based biocomposites

    Science.gov (United States)

    Arias Herrera, Andrea Marcela

    Polylactide or PLA is a biodegradable polymer that can be produced from renewable resources. This aliphatic polyester exhibits good mechanical properties similar to those of polyethylene terephthalate (PET). Since 2003, bio-based high molecular weight PLA is produced on an industrial scale and commercialized under amorphous and semicrystalline grades for various applications. Enhancement of PLA crystallization kinetics is crucial for the competitiveness of this biopolymer as a commodity material able to replace petroleum-based plastics. On the other hand, the combination of natural fibers with polymer matrices made from renewable resources, to produce fully biobased and biodegradable polymer composite materials, has been a strong trend in research activities during the last decade. Nevertheless, the differences related to the chemical structure, clearly observed in the marked hydrophilic/hydrophobic character of the fibers and the thermoplastic matrix, respectively, represent a major drawback for promoting strong fiber/matrix interactions. The aim of the present study was to investigate the intrinsic fiber/matrix interactions of PLAbased natural fiber composites prepared by melt-compounding. Short flax fibers presenting a nominal length of ˜1 mm were selected as reinforcement and biocomposites containing low to moderate fiber loading were processed by melt-mixing. Fiber bundle breakage during processing led to important reductions in length and diameter. The mean aspect ratio was decreased by about 50%. Quiescent crystallization kinetics of PLA and biocomposite systems was examined under isothermal and non-isothermal conditions. The nucleating nature of the flax fibers was demonstrated and PLA crystallization was effectively accelerated as the natural reinforcement content increased. Such improvement was controlled by the temperature at which crystallization took place, the liquid-to-solid transition being thermodynamically promoted by the degree of supercooling

  13. The comparison of properties and cost of material use of natural rubber and sand in manufacturing cement mortar for construction sub-base layer

    Science.gov (United States)

    Rahman, R.; Nemmang, M. S.; Hazurina, Nor; Shahidan, S.; Khairul Tajuddin Jemain, Raden; Abdullah, M. E.; Hassan, M. F.

    2017-11-01

    The main issue related to this research was to examine the feasibility of natural rubber SMR 20 in the manufacturing of cement mortar for sub-base layer construction. Subbase layers have certain functions that need to be fulfilled in order to assure strong and adequate permeability of pavement performance. In a pavement structure, sub-base is below the base and serves as the foundation for the overall pavement structure, transmitting traffic loads to the sub-grade and providing drainage. Based on this research, the natural rubber, SMR 20 was with the percentages of 0%, 5%, 10% and 15% to mix with sand in the manufacture of the cement mortar. This research describes some of the properties and cost of the materials for the natural rubber and sand in cement mortar manufacturing by laboratory testing. Effects of the natural rubber replacement on mechanical properties of mortar were investigated by laboratory testing such as compressive strength test and density. This study obtained the 5% of natural rubber replaced in sand can achieved the strength of normal mortar after 7 days and 28 days. The strength of cement mortar depends on the density of cement mortar. According to the cost of both materials, sand shows the lower cost in material for the cement mortar manufacturing than the uses of natural rubber. Thus, the convectional cement mortar which used sand need lower cost than the modified rubber cement mortar and the most economical to apply in industrial. As conclusion, the percentage of 5% natural rubber in the cement mortar would have the same with normal cement mortar in terms of the strength. However, in terms of the cost of the construction, it will increase higher than cost of normal cement mortar production. So that, this modified cement mortar is not economical for the road sub-base construction.

  14. Kenaf-and hemp-reinforced natural fibre composites

    International Nuclear Information System (INIS)

    Sharifah Hanisah Aziz

    2003-01-01

    The main aim of this research is to combine hemp and kenaf fibres with thermosetting resin matrices to produce sustainable composites and to investigate their mechanical properties. The matirces used in this work are based on either unsaturated polyester resins or cashew nut shell liquid (CNSL). The latter can be polymerised to form a phenolic-based natural resin. Four types of differently formulated polyester resins provided by Scott Bader Ltd, a UK-based resin company, were used to assess the effect of resin formulation on the properties of natural fibre composites. CSNL resins were used because CNSL is a sustainable resource and these resins are compatible with natural fibres. Kenaf, which is extensively grown in the Far East including Malaysia, has been identified as a bast (stem) fibre with significant market potential. Hemp is a United Kingdom-grown bast fibre with strong potential as a natural fibre reinforcement. In order to improve matrix to fibre adhesion, the fibres were treated with 6 % NaOH solution before being made into composites. The composites were fabricated using unidirectional and randomly oriented fibres to assess the effect of fibre alignment on the properties of the composites. The effect of moulding pressure on the fibre volume fraction and mechanical properties was also investigated. Kenaf and hemp fibre composites were successfully hot-pressed with polyester and CNSL resin matrices. Kenaf-CNSL (treated long fibre) composites possess the highest flexural modulus (MOE) at 16.7 GPa and flexural strength (MOR) at 165.4 MPa indicating good matrix to fibre adhesion. Generally, the treated fibre composites gave higher MOE and MOR values compared to the untreated composites. However, the work of fracture values were generally higher for the untreated fibre composites. among the four types of polyester used, the molecular structure of polyester B, modified to make it more polar in nature, resulted in the best performance with treated long kenaf

  15. Thermomyces lanuginosus STm: a source of thermostable hydrolytic enzymes for novel application in extraction of high-quality natural rubber from Taraxacum kok-saghyz (rubber dandelion)

    Science.gov (United States)

    Hydrolytic enzymes from a newly isolated strain of the thermophilic fungus Thermomyces lanuginosus were used to extract rubber from Taraxacum kok-saghyz commonly known as rubber (or Russian or Kazak(h)) dandelion. The fungus was isolated from garden soil and identified as Thermomyces lanuginosus STm...

  16. Analysis of temperature profile and electric field in natural rubber glove due to microwave heating: effects of waveguide position

    Science.gov (United States)

    Keangin, P.; Narumitbowonkul, U.; Rattanadecho, P.

    2018-01-01

    Natural rubber (NR) is the key raw material used in the manufacture of other products such as rubber band, tire and shoes. Recently, the NR is used in natural rubber glove ( NRG) manufacturing in the industrial and medical fields. This research aims to investigate the electromagnetic wave propagation and heat transfer in NRG due to heating with microwave energy within the microwave oven at a microwave frequency of 2.45 GHz. Three-dimensional model of NRG and microwave oven are considered in this work. The comparative effects of waveguide position on the electric field and temperature profile in NRG when subjected to microwave energy are discussed. The finite element method (FEM) is used to solve the transient Maxwell’s equation coupled with the transient heat transfer equation. The simulation results with computer programs are validated with experimental results. The placement of waveguides in three cases are left hand side of microwave oven, right hand side of microwave oven and left and right hand sides of microwave oven are investigated. The findings revealed that the placing the waveguide on the right side of the microwave oven gives the highest electric field and temperature profile. The values obtained provide an indication toward understanding the study of heat transfer in NRG during microwave heating in the industry.

  17. Surface modification of argon/oxygen plasma treated vulcanized ethylene propylene diene polymethylene surfaces for improved adhesion with natural rubber

    International Nuclear Information System (INIS)

    Basak, Ganesh C.; Bandyopadhyay, Abhijit; Neogi, Sudarsan; Bhowmick, Anil K.

    2011-01-01

    Vulcanized ethylene propylene diene polymethylene (EPDM) rubber surface was treated in a radio frequency capacitatively coupled low pressure argon/oxygen plasma to improve adhesion with compounded natural rubber (NR) during co-vulcanization. The plasma modified surfaces were analyzed by means of contact angle measurement, surface energy, attenuated total reflection-infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, energy dispersive X-ray sulfur mapping and atomic force microscopy. Several experimental variables such as plasma power, length of exposure time and composition of the argon-oxygen gas mixture were considered. It was delineated that plasma treatment changed both surface composition and roughness, and consequently increased peel strength. The change in surface composition was mainly ascribed to the formation of C-O and -C=O functional groups on the vulcanized surfaces. A maximum of 98% improvement in peel strength was observed after plasma treatment.

  18. Multi-objective optimization of process conditions in the manufacturing of banana (Musa paradisiaca L.) starch/natural rubber films.

    Science.gov (United States)

    Ramírez-Hernández, A; Aparicio-Saguilán, A; Reynoso-Meza, G; Carrillo-Ahumada, J

    2017-02-10

    Multi-objective optimization was used to evaluate the effect of adding banana (Musa paradisiaca L.) starch and natural rubber (cis-1,4-poliisopreno) at different ratios (1-13w/w) to the manufacturing process of biodegradable films, specifically the effect on the biodegradability, crystallinity and moisture of the films. A structural characterization of the films was performed by X-ray diffraction, Fourier transform infrared spectroscopy and SEM, moisture and biodegradability properties were studied. The models obtained showed that degradability vs. moisture tend to be inversely proportional and crystallinity vs. degradability tend to be directly proportional. With respect to crystallinity vs. moisture behavior, it is observed that crystallinity remains constant when moisture values remain between 27 and 41%. Beyond this value there is an exponential increase in crystallinity. These results allow for predictions on the mechanical behavior that can occur in starch/rubber films. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Surface modification of argon/oxygen plasma treated vulcanized ethylene propylene diene polymethylene surfaces for improved adhesion with natural rubber

    Energy Technology Data Exchange (ETDEWEB)

    Basak, Ganesh C. [Rubber Technology Centre, Indian Institute of Technology, Kharagpur 721302 (India); Bandyopadhyay, Abhijit [Department of Polymer Science and Technology, University of Calcutta, Calcutta 700 009 (India); Neogi, Sudarsan [Department of Chemical Engineering, Indian Institute of Technology, Kharagpur 721302 (India); Bhowmick, Anil K., E-mail: anilkb@rtc.iitkgp.ernet.in [Rubber Technology Centre, Indian Institute of Technology, Kharagpur 721302 (India)

    2011-01-15

    Vulcanized ethylene propylene diene polymethylene (EPDM) rubber surface was treated in a radio frequency capacitatively coupled low pressure argon/oxygen plasma to improve adhesion with compounded natural rubber (NR) during co-vulcanization. The plasma modified surfaces were analyzed by means of contact angle measurement, surface energy, attenuated total reflection-infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, energy dispersive X-ray sulfur mapping and atomic force microscopy. Several experimental variables such as plasma power, length of exposure time and composition of the argon-oxygen gas mixture were considered. It was delineated that plasma treatment changed both surface composition and roughness, and consequently increased peel strength. The change in surface composition was mainly ascribed to the formation of C-O and -C=O functional groups on the vulcanized surfaces. A maximum of 98% improvement in peel strength was observed after plasma treatment.

  20. Outcomes of a natural rubber latex control program in an Ontario teaching hospital.

    Science.gov (United States)

    Tarlo, S M; Easty, A; Eubanks, K; Parsons, C R; Min, F; Juvet, S; Liss, G M

    2001-10-01

    Allergy to natural rubber latex (NRL) has been frequently reported in health care workers. However, there is little published evidence of the outcome of hospital intervention programs to reduce exposure and detect cases of sensitization early. This study assesses the effects of intervention to reduce NRL allergy in an Ontario teaching hospital with approximately 8000 employees. A retrospective review assessed annual numbers of employees visiting the occupational health clinic, allergy clinic, or both for manifestations of NRL allergy compared with the timing of introduction of intervention strategies, such as worker education, voluntary medical surveillance, and hospital conversion to low-protein, powder-free NRL gloves. The number of workers identified with NRL allergy rose annually, from 1 in 1988 to 6 in 1993. When worker education and voluntary medical surveillance were introduced in 1994, a further 25 workers were identified. Nonsterile gloves were changed to low-protein, powder-free NRL gloves in 1995: Diagnoses fell to 8 workers that year, and 2 of the 3 nurses who had been off work because of asthma-anaphylaxis were able to return to work with personal avoidance of NRL products. With a change to lower protein, powder-free NRL sterile gloves in 1997, allergy diagnoses fell to 3, and only 1 new case was identified subsequently up to May 1999. No increased glove costs were incurred as a result of consolidated glove purchases. This program to reduce NRL allergy in employees was effectively achieved without additional glove costs while reducing expenses from time off work and workers' compensation claims.

  1. Synthesis, characterization and impedance spectroscopy study of magnetite/epoxidized natural rubber nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Tan, W.L. [Nanoscience Research Laboratory, School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang (Malaysia); Abu Bakar, M., E-mail: bmohamad@usm.my [Nanoscience Research Laboratory, School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang (Malaysia)

    2013-06-05

    Highlights: ► The Fe{sub 3}O{sub 4}/ENR nanocomposites have not been synthesized and reported. ► Nanocomposites were obtained via in situ synthesis of Fe{sub 3}O{sub 4} in the presence of ENR. ► The use of ENR enabled control of the size of Fe{sub 3}O{sub 4} particles to <20 nm. ► Conductivity of the nanocomposites increases with the increase in Fe{sub 3}O{sub 4} loading. ► The equivalent circuit for the nanocomposites is proposed and discussed. -- Abstract: The magnetite (Fe{sub 3}O{sub 4}) particles were synthesized in situ in the presence of epoxidized natural rubber (ENR) to produce the various Fe{sub 3}O{sub 4}/ENR nanocomposites. The X-ray diffraction (XRD) analysis confirmed the existence of Fe{sub 3}O{sub 4} particles in the composites. The FTIR and DSC studies suggested that no chemical interactions between the particles and the matrix. The SEM and X-mapping micrographs revealed that the Fe{sub 3}O{sub 4} particles were distributed within the ENR matrix. The ENR matrix exerts control on the Fe{sub 3}O{sub 4} particles with a size of <20 nm in the composites. The Fe{sub 3}O{sub 4} particles also affect the electrical properties of the composites. Impedance spectroscopy studies show that the electrical conductivity of the nanocomposites increases with the increase in Fe{sub 3}O{sub 4} loading in the composite. The equivalent circuit for the Fe{sub 3}O{sub 4}/ENR nanocomposites is proposed and discussed.

  2. Novel mesoporous composites based on natural rubber and hexagonal mesoporous silica: Synthesis and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Nuntang, Sakdinun; Poompradub, Sirilux [Fuels Research Center, Department of Chemical Technology, Faculty of Science, Chulalongkorn University, Patumwan, Bangkok 10330 (Thailand); Butnark, Suchada [PTT Research and Technology Institute, PTT Public Company Limited, Wangnoi, Ayutthaya 13170 (Thailand); Yokoi, Toshiyuki; Tatsumi, Takashi [Division of Catalytic Chemistry, Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503 (Japan); Ngamcharussrivichai, Chawalit, E-mail: Chawalit.Ng@Chula.ac.th [Fuels Research Center, Department of Chemical Technology, Faculty of Science, Chulalongkorn University, Patumwan, Bangkok 10330 (Thailand); Center of Excellence on Petrochemical and Materials Technology (PETROMAT), Chulalongkorn University, Patumwan, Bangkok 10330 (Thailand)

    2014-02-14

    The present study is the first report on the synthesis and characterization of mesoporous composites based on natural rubber (NR) and hexagonal mesoporous silica (HMS). A series of NR/HMS composites were prepared in tetrahydrofuran via an in situ sol–gel process using tetraethylorthosilicate as the silica precursor. The physicochemical properties of the composites were characterized by various techniques. The effects of the gel composition on the structural and textural properties of the NR/HMS composites were investigated. The Fourier-transform infrared spectroscopy (FTIR) and {sup 29}Si magic angle spinning nuclear magnetic resonance ({sup 29}Si MAS NMR) results revealed that the surface silanol groups of NR/HMS composites were covered with NR molecules. The powder X-ray diffraction (XRD) and transmission electron microscopy (TEM) data indicated an expansion of the hexagonal unit cell and channel wall thickness due to the incorporation of NR molecules into the mesoporous structure. NR/HMS composites also possessed nanosized particles (∼79.4 nm) as confirmed by scanning electron microscopy (SEM) and particle size distribution analysis. From N{sub 2} adsorption–desorption measurement, the NR/HMS composites possessed a high BET surface area, large pore volume and narrow pore size distribution. Further, they were enhanced hydrophobicity confirmed by H{sub 2}O adsorption–desorption measurement. In addition, the mechanistic pathway of the NR/HMS composite formation was proposed. - Highlights: • NR molecules were incorporated into hexagonal meso-structure of HMS. • NR/HMS composites exhibited an expanded unit cell and channel wall thickness. • Nanosized NR/HMS composites with a lower particle size range were obtained. • NR/HMS had high surface area, large pore volume and narrow pore size distribution. • NR/HMS composites displayed an enhanced hydrophobicity.

  3. Mechanical properties, morphology, and hydrolytic degradation behavior of polylactic acid / natural rubber blends

    Science.gov (United States)

    Buys, Y. F.; Aznan, A. N. A.; Anuar, H.

    2018-01-01

    Due to its biodegradability and renewability, polylactic acid (PLA) has been receiving enormous attention as a potential candidate to replace petroleum based polymers. However, PLA has limitation due to its inherent brittleness. In order to overcome this limitation, blending PLA with elastomeric materials such as natural rubber (NR) are commonly reported. In previous, several researches on PLA/NR blend had been reported, with most of them evaluated the mechanical properties. On the other hand, study of degradation behavior is significance of importance, as controlling materials degradation is required in some applications. This research studied the effect of blend composition on mechanical properties, morphology development, and hydrolytic degradation behavior of PLA/NR blends. Various compositions of PLA/NR blends were prepared by melt blending technique. Tensile test and impact test of the blends were performed to evaluate the mechanical properties. Addition of NR improved the elongation at break and impact strength of the blends, but reduced the tensile strength and stiffness of the specimens. Dynamic Mechanical Analysis (DMA) measurements of the blends displayed two peaks at temperature -70˚C which corresponded to T g of NR and 65˚C which corresponded to T g of PLA. Field Emission Scanning Electron Microscopy (FE-SEM) micrograph of 70/30 PLA/NR specimen also showed two distinct phases, which lead to indication that PLA/NR blends are immiscible. Hydrolytic degradation behavior was evaluated by measuring the remaining weight of the samples immersed in sodium hydroxide solution for a predetermined times. It was shown that the degradation behavior of PLA/NR blends is affected by composition of the blends, with 100 PLA and 70/30 PLA/NR blend showed the fastest degradation rate and 100 NR displayed the slowest one.

  4. Syntheses, spectroscopic characterization, crystal structure and natural rubber vulcanization activity of new disulfides derived from sulfonyldithiocarbimates

    Science.gov (United States)

    Alves, Leandro de Carvalho; Rubinger, Mayura Marques Magalhães; Tavares, Eder do Couto; Janczak, Jan; Pacheco, Elen Beatriz Acordi Vasques; Visconte, Leila Lea Yuan; Oliveira, Marcelo Ribeiro Leite

    2013-09-01

    The compounds (Bu4N)2[(4-RC6H4SO2NCS2)2] [Bu4N = tetrabutylammonium cation; R = H (1), F (2), Cl (3) and Br (4)] and (Ph4P)2[(4-RC6H4SO2NCS2)2]ṡH2O [Ph4P = tetraphenylphosphonium cation and R = I (5)] were synthesized by the reaction of the potassium dithiocarbimates (4-RC6H4SO2NCS2K2ṡ2H2O) with I2 and Bu4NBr or Ph4PCl. The IR data were consistent with the formation of the dithiocarbimatodisulfides anions. The NMR spectra showed the expected signals for the cations and anions in a 2:1 proportion. The structures of compounds 1-5 were determined by the single crystal X-ray diffraction. The compounds 2, 3 and 4 are isostructural and crystallise in the centrosymmetric space group C2/c of the monoclinic system. Compound 1 crystallises in the monoclinic system in the space group of P21/n and the compound 5 crystallises in the centrosymmetric space group P-1 of the triclinic system. The complex anions of compounds 2, 3 and 4 exhibit similar conformations having twofold symmetry, while in 1 and 5 the anions exhibit C1 symmetry. The activity of the new compounds in the vulcanization of the natural rubber was evaluated and compared to the commercial accelerators ZDMC, TBBS and TMTD. These studies confirm that the sulfonyldithiocarbimato disulfides anions are new vulcanization accelerators, being slower than the commercial accelerators, but producing a greater degree of crosslinking, and scorch time values compatible with good processing safety for industrial applications. The mechanical properties, stress and tear resistances were determined and compared to those obtained with the commercial accelerators.

  5. Evaluation of sodium diclofenac release using natural rubber latex as carrier

    International Nuclear Information System (INIS)

    Aielo, Patricia B.; Borges, Felipe A.; Romeira, Karoline M.; Herculano, Rondinelli D.; Miranda, Matheus Carlos Romeiro; Arruda, Larisa B. de; Lisboa Filho, Paulo Noronha; Drago, Bruno de C.

    2014-01-01

    Sodium Diclofenac is a non-steroidal anti-inflammatory drug (NSAID) taken to reduce inflammation and, as an analgesic, reduce pain. Although this drug is widely used in the general population, properties such as the short half-time and some side effects restrict its clinical use. The most common side effects are: gastric irritation, gastritis, peptic ulcer and bleeding. Studies involving biomaterials as carrier for drug release have been proving their efficiency in overcoming those problems and better controlling the release rate and targeting of the drug. Natural rubber latex (NRL) has been proven excellent for its biocompatibility and ability to stimulate angiogenesis, cellular adhesion and the formation of extracellular matrix, promoting the replacement and regeneration of tissue. In this work, a NRL membrane is used to deliver sodium diclofenac. Sodium diclofenac (NaDic) was found to be adsorbed on the NRL membrane, with little or no incorporation into the membrane bulk, according to energy dispersive Scanning Electron Microscopy with X-Ray microanalysis (SEM-EDS) spectroscopy. In addition, FT-IR shows that there is no molecular-level interaction between drug and NRL. Already, the X-Ray Diffraction (XRD) of NaDic-NRL shows a broader one spectrum than the sharper halo (amorphous characteristic XRD spectrum) of pure NRL. More importantly, the release time of diclofenac in a NRL membrane in vitro was increased from the typical 2-3 h for oral tablets to ca. 74 h. The kinetics of the drug release could be fitted with a double exponential function, with two characteristic times of 0.899 and 32.102 h. In this study, we demonstrated that the interesting properties provided by NRL membranes combined with a controlled release of drug is relevant for biomedical applications.(author)

  6. Evaluation of sodium diclofenac release using natural rubber latex as carrier

    Energy Technology Data Exchange (ETDEWEB)

    Aielo, Patricia B.; Borges, Felipe A.; Romeira, Karoline M.; Herculano, Rondinelli D., E-mail: rond@assis.unesp.br [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Assis, SP (Brazil). Fac. de Ciencias e Letras. Dept. de Ciencias Biologicas; Miranda, Matheus Carlos Romeiro [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Araraquara, SP (Brazil). Inst. de Quimica; Arruda, Larisa B. de; Lisboa Filho, Paulo Noronha; Drago, Bruno de C. [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Bauru, SP (Brazil). Fac. de Ciencias. Dept. de Fisica

    2014-08-15

    Sodium Diclofenac is a non-steroidal anti-inflammatory drug (NSAID) taken to reduce inflammation and, as an analgesic, reduce pain. Although this drug is widely used in the general population, properties such as the short half-time and some side effects restrict its clinical use. The most common side effects are: gastric irritation, gastritis, peptic ulcer and bleeding. Studies involving biomaterials as carrier for drug release have been proving their efficiency in overcoming those problems and better controlling the release rate and targeting of the drug. Natural rubber latex (NRL) has been proven excellent for its biocompatibility and ability to stimulate angiogenesis, cellular adhesion and the formation of extracellular matrix, promoting the replacement and regeneration of tissue. In this work, a NRL membrane is used to deliver sodium diclofenac. Sodium diclofenac (NaDic) was found to be adsorbed on the NRL membrane, with little or no incorporation into the membrane bulk, according to energy dispersive Scanning Electron Microscopy with X-Ray microanalysis (SEM-EDS) spectroscopy. In addition, FT-IR shows that there is no molecular-level interaction between drug and NRL. Already, the X-Ray Diffraction (XRD) of NaDic-NRL shows a broader one spectrum than the sharper halo (amorphous characteristic XRD spectrum) of pure NRL. More importantly, the release time of diclofenac in a NRL membrane in vitro was increased from the typical 2-3 h for oral tablets to ca. 74 h. The kinetics of the drug release could be fitted with a double exponential function, with two characteristic times of 0.899 and 32.102 h. In this study, we demonstrated that the interesting properties provided by NRL membranes combined with a controlled release of drug is relevant for biomedical applications.(author)

  7. Natural Contamination and Surface Flashover on Silicone Rubber Surface under Haze–Fog Environment

    Directory of Open Access Journals (Sweden)

    Ang Ren

    2017-10-01

    Full Text Available Anti-pollution flashover of insulator is important for power systems. In recent years, haze-fog weather occurs frequently, which makes discharge occurs easily on the insulator surface and accelerates insulation aging of insulator. In order to study the influence of haze-fog on the surface discharge of room temperature vulcanized silicone rubber, an artificial haze-fog lab was established. Based on four consecutive years of insulator contamination accumulation and atmospheric sampling in haze-fog environment, the contamination configuration appropriate for RTV-coated surface discharge test under simulation environment of haze-fog was put forward. ANSYS Maxwell was used to analyze the influence of room temperature vulcanized silicone rubber surface attachments on electric field distribution. The changes of droplet on the polluted room temperature vulcanized silicone rubber surface and the corresponding surface flashover voltage under alternating current (AC, direct current (DC positive polar (+, and DC negative polar (− power source were recorded by a high speed camera. The results are as follows: The main ion components from haze-fog atmospheric particles are NO3−, SO42−, NH4+, and Ca2+. In haze-fog environment, both the equivalent salt deposit density (ESDD and non-soluble deposit density (NSDD of insulators are higher than that under general environment. The amount of large particles on the AC transmission line is greater than that of the DC transmission line. The influence of DC polarity power source on the distribution of contamination particle size is not significant. After the deposition of haze-fog, the local conductivity of the room temperature vulcanized silicone rubber surface increased, which caused the flashover voltage reduce. Discharge is liable to occur at the triple junction point of droplet, air, and room temperature vulcanized silicone rubber surface. After the deformation or movement of droplets, a new triple junction

  8. Compósitos de Borracha Natural com Compostos Condutivos à Base de Negro de Fumo e Polímero Condutor Natural Rubber Composites with Conductive Compounds based on Carbon Black and Conducting Polymers

    Directory of Open Access Journals (Sweden)

    Marinalva A. dos Santos

    2001-09-01

    Full Text Available Neste trabalho foram desenvolvidos compósitos condutores elétricos de borracha natural contendo negro de fumo e compostos condutivos baseados em polímeros condutores (Eenomer®. Os compósitos foram processados a quente num reômetro de torque HAAKE e moldados por prensagem. Foram obtidas placas homogêneas, flexíveis e com ótimo acabamento superficial. Os compósitos foram analisados pelas medidas de torque no processamento, medidas de condutividade elétrica, análise termogravimétrica (TGA, calorimetria diferencial de varredura (DSC e ensaios de tração. Estes compósitos apresentaram valores de condutividade elétrica entre 10-7 a 10-1 S/cm, dependendo do tipo de negro de fumo ou composto condutivo utilizado e da quantidade destes no compósito. A análise térmica demonstrou que os compósitos são termicamente estáveis até cerca de 300°C. Os compostos condutivos atuam como reforço para a borracha natural melhorando suas propriedades mecânicas sem perder significativamente sua flexibilidade.In this work, electrically conducting composites of natural rubber with carbon black and natural rubber with conductive compounds containing electrically conducting polymers (Eenomer® were developed. The composites were processed in a torque reometer HAAKE and then hot pressed. Homogeneous and flexible plates were obtained with excellent surface finish. The composites were analysed by the torque measurement during processing, electrical conductivity, thermogravimetric analysis (TGA, differential scanning calorimetric (DSC and mechanical analysis. Conductivity in the order of 10-7 to 10-1 S/cm were achieved, depending on the type of carbon black or conductive compound used and their content in the composite. Thermal analysis demonstrated that the compounds are thermally stable until 300°C. The conductive compounds act as reinforcements in the natural rubber matrix, improving its mechanical properties without significant loss on its

  9. Cure and mechanical properties of recycled NdFeB–natural rubber ...

    Indian Academy of Sciences (India)

    Administrator

    crosslink. The tensile strength of the NR compound, related to the cure characteristics, was reduced by 40% ... Sample (phr; part per hundred rubber). Ingredient. A. B. C. D. E. F. NR (ADS). 100 ... machine (Retsch PM100) at 300 rpm for 1 h.

  10. Rubber industry

    Science.gov (United States)

    Staszak, Maciej

    2018-03-01

    Following chapter presents short introductory description of rubber and rubber industry. The main problem of rubber industry is the way of the usage of spent tires. Furthermore very important group of problems arise considering the metal and nonmetal additives which are significant component of the vulcanized rubber. The key attention is dedicated to typical ways of rubber usage in utilization and recovery of metals from spent rubber materials concentrating specifically on used tires processing. The method of recovery of rare metals from rubber tires was described. The rubber debris finds widest use in the field of waste metal solutions processing. The environmental pollution caused by metals poses serious threat to humans. Several applications of the use of waste rubber debris to remove metals from environmental waters were described. Moreover, the agriculture usage of waste tire rubber debris is described, presenting systems where the rubber material can be useful as a soil replacement.

  11. Prevalence of Allergy to Natural Rubber Latex and Potential Cross Reacting Food in Operation Room Staff in Shiraz Hospitals -2006

    Directory of Open Access Journals (Sweden)

    H Nabavizade

    2007-07-01

    Full Text Available Introduction & Objective: Allergic reactions to natural rubber latex have increased during past 10 years especially among health care workers and patients with high exposure to latex allergens. Allergic reaction to latex is related to many diseases like occupational asthma. This study was performed to determine the prevalence of allergy to natural rubber latex and potential cross reacting food in operation room staff in Shiraz hospitals. Materials & Methods: In this cross-sectional descriptive study five hundred eighty operation room staff of ten private and state hospitals in Shiraz completed latex allergy questionnaire. They were questioned about personal history and previous history of latex sensitivity, symptoms of latex reactivity and about other allergies particularly to foods that may cross react with latex. Informed consent was obtained and skin prick testing was performed with natural rubber latex. Skin prick tests were done with three potentially cross reacting food (banana, Kiwi, and potato. The obtained data were analyzed with SPSS software and Chi-square test. Results: Among the 580 operation room workers 104 (17.9 % of participants were positive to latex skin test. We found a significant association between positive skin test to latex in operation room staff and atopy, urticaria and food allergy. Positive skin test to latex related to positive kiwi skin test (p<0.05. The prevalence did not vary by sex, age, education, surgical and non surgical glove users, history of contact dermatitis or smoking status. Conclusion: Latex allergy has a high prevalence in personnel of operation room. Evaluation of present symptom and prediction of future disease necessitate screening test in individuals at risk.

  12. Organosulfonic acid-functionalized mesoporous composites based on natural rubber and hexagonal mesoporous silica

    Energy Technology Data Exchange (ETDEWEB)

    Nuntang, Sakdinun; Poompradub, Sirilux [Fuels Research Center, Department of Chemical Technology, Faculty of Science, Chulalongkorn University, Patumwan, Bangkok 10330 (Thailand); Butnark, Suchada [PTT Research and Technology Institute, PTT Public Company Limited, Wangnoi, Ayutthaya 13170 (Thailand); Yokoi, Toshiyuki; Tatsumi, Takashi [Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503 (Japan); Ngamcharussrivichai, Chawalit, E-mail: Chawalit.Ng@Chula.ac.th [Fuels Research Center, Department of Chemical Technology, Faculty of Science, Chulalongkorn University, Patumwan, Bangkok 10330 (Thailand); Center of Excellence on Petrochemical and Materials Technology (PETROMAT), Chulalongkorn University, Patumwan, Bangkok 10330 (Thailand)

    2014-10-15

    This study is the first report on synthesis, characterization and catalytic application of propylsulfonic acid-functionalized mesoporous composites based on natural rubber (NR) and hexagonal mesoporous silica (HMS). In comparison with propylsulfonic acid-functionalized HMS (HMS-SO{sub 3}H), a series of NR/HMS-SO{sub 3}H composites were prepared via an in situ sol–gel process using tetrahydrofuran as the synthesis media. Tetraethylorthosilicate as the silica source, was simultaneously condensed with 3-mercaptopropyltrimethoxysilane in a solution of NR followed by oxidation with hydrogen peroxide to achieve the mesoporous composites containing propylsulfonic acid groups. Fourier-transform infrared spectroscopy and {sup 29}Si MAS nuclear magnetic resonance spectroscopy results verified that the silica surfaces of the NR/HMS-SO{sub 3}H composites were functionalized with propylsulfonic acid groups and covered with NR molecules. After the incorporation of NR and organo-functional group into HMS, the hexagonal mesostructure remained intact concomitantly with an increased framework wall thickness and unit cell size, as evidenced by the X-ray powder diffraction analysis. Scanning electron microscopy analysis indicated a high interparticle porosity of NR/HMS-SO{sub 3}H composites. The textural properties of NR/HMS-SO{sub 3}H were affected by the amount of MPTMS loading to a smaller extent than that of HMS-SO{sub 3}H. NR/HMS-SO{sub 3}H exhibited higher hydrophobicity than HMS-SO{sub 3}H, as revealed by H{sub 2}O adsorption–desorption measurements. Moreover, the NR/HMS-SO{sub 3}H catalysts possessed a superior specific activity to HMS-SO{sub 3}H in the esterification of lauric acid with ethanol, resulting in a higher conversion level. - Highlights: • Acidic NR/HMS-SO{sub 3}H composites were prepared by in situ sol–gel process. • Propylsulfonic acid was functionalized onto HMS surface by direct co-condensation. • NR/HMS-SO{sub 3}H exhibited a hexagonal

  13. Shell structure of natural rubber particles: evidence of chemical stratification by electrokinetics and cryo-TEM.

    Science.gov (United States)

    Rochette, Christophe N; Crassous, Jérôme J; Drechsler, Markus; Gaboriaud, Fabien; Eloy, Marie; de Gaudemaris, Benoît; Duval, Jérôme F L

    2013-11-26

    The interfacial structure of natural rubber (NR) colloids is investigated by means of cryogenic transmission electron microscopy (cryo-TEM) and electrokinetics over a broad range of KNO3 electrolyte concentrations (4-300 mM) and pH values (1-8). The asymptotic plateau value reached by NR electrophoretic mobility (μ) in the thin double layer limit supports the presence of a soft (ion- and water-permeable) polyelectrolytic type of layer located at the periphery of the NR particles. This property is confirmed by the analysis of the electron density profile obtained from cryo-TEM that evidences a ∼2-4 nm thick corona surrounding the NR polyisoprene core. The dependence of μ on pH and salt concentration is further marked by a dramatic decrease of the point of zero electrophoretic mobility (PZM) from 3.6 to 0.8 with increasing electrolyte concentration in the range 4-300 mM. Using a recent theory for electrohydrodynamics of soft multilayered particles, this "anomalous" dependence of the PZM on electrolyte concentration is shown to be consistent with a radial organization of anionic and cationic groups across the peripheral NR structure. The NR electrokinetic response in the pH range 1-8 is indeed found to be equivalent to that of particles surrounded by a positively charged ∼3.5 nm thick layer (mean dissociation pK ∼ 4.2) supporting a thin and negatively charged outermost layer (0.6 nm in thickness, pK ∼ 0.7). Altogether, the strong dependence of the PZM on electrolyte concentration suggests that the electrostatic properties of the outer peripheral region of the NR shell are mediated by lipidic residues protruding from a shell containing a significant amount of protein-like charges. This proposed NR shell interfacial structure questions previously reported NR representations according to which the shell consists of either a fully mixed lipid-protein layer, or a layer of phospholipids residing exclusively beneath an outer proteic film.

  14. Mechanical properties of natural fibre reinforced polymer composites

    Indian Academy of Sciences (India)

    Wintec

    initiated in our laboratory on synthesis and study of pro- perties of Hibiscus sabdariffa fibre reinforced urea– formaldehyde (U–F) resin matrix based biocomposites. 2. Experimental. 2.1 Material and methods. Urea (Qualigens Chemicals Ltd), formaldehyde solution. (Qualigens Chemicals Ltd.) and sodium hydroxide (Quali-.

  15. Mechanical properties of natural fibre reinforced polymer composites

    Indian Academy of Sciences (India)

    In the present communication, a study on the synthesis and mechanical properties of new series of green composites involving Hibiscus sabdariffa fibre as a reinforcing material in urea–formaldehyde (UF) resin based polymer matrix has been reported. Static mechanical properties of randomly oriented intimately mixed ...

  16. Report on the socio-economic impact of Natural Rubber cultivation under the block planting scheme in Tripura

    OpenAIRE

    Joseph, Joby; George K., Tharian; S.K, Dey

    2010-01-01

    The study is a pioneering attempt to assess the socio-economic impact of the Block Planting Scheme (BPS) from the angle of the beneficiaries,implementing agencies and the policymakers.The report is based on the primary information gathered from 480 households drawn from Block Planting Units with mature (Mature BPUs)and immature (Immature BPUs) area under Natural Rubber (NR) as well as households attached to Group Processing Scheme (GPUs) with mature area under NR during the year 2008.The trip...

  17. Application of Image And X-Ray Microtomography Technique To Quantify Filler Distribution In Thermoplastic-Natural Rubber Blend Composites

    International Nuclear Information System (INIS)

    Ahmad, Sahrim; Rasid, Rozaidi; Mouad, A. T.; Aziz Mohamed, A.; Abdullah, Jaafar; Dahlan, M.; Mohamad, Mahathir; Jamro, Rafhayudi; Hamzah Harun, M.; Yazid, Hafizal; Abdullah, W. Saffiey W.

    2010-01-01

    X-ray microtomography and ImageJ 1.39 u is used as a tool to quantify volume percentage of B 4 C as fillers in thermoplastic-natural rubber blend composites. The use of percentage of area occupied by fillers as obtain from ImageJ from the microtomography sliced images enables the proposed technique to easily obtain the amount volume percentage of B 4 C in the composite non-destructively. Comparison with other technique such as density measurement and chemical analysis proves the proposed technique as one of the promising approach.

  18. Novel Polyvinyl Alcohol/Styrene Butadiene Rubber Latex/Carboxymethyl Cellulose Nanocomposites Reinforced with Modified Halloysite Nanotubes

    Directory of Open Access Journals (Sweden)

    Yanjun Tang

    2013-01-01

    Full Text Available Novel polyvinyl alcohol (PVA/styrene butadiene rubber (SBR latex/carboxymethyl cellulose (CMC/halloysite nanotubes (HNTs nanocomposites were successfully prepared through physical blending. The as-obtained PVA/SBR/CMC/HNTs nanocomposites were coated on the surface of old corrugated container (OCC-based paper in an effort to improve the mechanical properties of paper. To improve the dispersion of HNTs and enhance the compatibility between HNTs and polymer matrix, HNTs were modified with titanate coupling agent (TCA. FT-IR, together with TGA, confirmed that TCA was grafted onto the surface of HNTs successfully. XRD demonstrated that the crystal structures of HNTs remained almost unchanged. TEM showed that modified HNTs exhibited good dispersion and possessed nanotubular structures with an outer diameter of around 50 nm and an inner diameter of about 20 nm. SEM gave an indication that modified HNTs were dispersed more uniformly than unmodified HNTs within PVA/SBR/CMC matrix. Rheological measurement exhibited that surface modification process enhanced the compatibility between HNTs and polymer matrix, thus resulting in the decreased viscosity of nanocomposites. In comparison with unmodified HNTs, modified HNTs were found to contribute more to the enhancement in mechanical properties, which might be attributed to the better dispersion and compatibility of modified HNTs evidenced by TEM, SEM, and rheological measurement.

  19. Plane-interface-induced lignin-based nanosheets and its reinforcing effect on styrene-butadiene rubber

    Directory of Open Access Journals (Sweden)

    C. Jiang

    2014-09-01

    Full Text Available Lignin was viewed as a spherical microgel in aqueous alkali. While spread out in a monolayer or adsorbed on a surface, lignin was made up of flexible, disk-like molecules with approximately the same thickness of 2 nm. According to this principle, we employed the lamina of montmorillonite (MMT as a plane template to anchor cationic lignin (CL on its two sides, resulting in the formation of CL-MMT hybrid materials (CLM. The isotherm adsorption behavior and structure characteristics of CLM were studied. The results showed that CLM was individually dispersed nanosheets with a thickness of about 5 nm when the mass ratio of CL to MMT is more than 2:1 and prepared at acidic or neutral pH. Compared to the cocoagulation of lignin and styrene-butadiene rubber (SBR, CLM obviously accelerated the coagulation rate, due to the reduction of surface activity of CL restricted by MMT. The nanoscale dispersion of CLM in SBR matrix significantly improved the tensile strength of CLM/SBR nanocomposites to 14.1 MPa by adding only 10 phr CLM and cardanol glycidyl ether (CGE as compatibilizer. Dynamic mechanical analysis (DMA showed that the glass transition temperature of SBR/CLM nanocomposites decreased with increasing CLM loading. Correspondingly, a special interfacial structure was proposed.

  20. Evaluation of natural rubber from IAC series clones by solid state {sup 13}C NMR; Avaliacao da borracha natural de clones da serie IAC por {sup 13}C RMN no estado solido

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Maria A.; Moreno, Rogerio M.B.; Goncalves, Paulo S. [Instituto Agronomico de Campinas, SP (Brazil). Centro de Cafe e Plantas Tropicais. Programa Seringueira]. E-mails: paulog@iac.sp.gov.br; mariaalice@cnpdia.embrapa.br; Forato, Lucimara A.; Colnago, Luiz A.; Mattoso, Luiz H.C. [EMBRAPA Instrumentacao Agropecuaria, Sao Carlos, SP (Brazil)]. E-mail: colnago@cnpdia.embrapa.br; forato@cnpdia.embrapa.br; rogerio@cnpdia.embrapa.br; mattoso@cnpdia.embrapa.br; Job, Aldo E. [Universidade Estadual Paulista (UNESP), Presidente Prudente, SP (Brazil). Departamento de Fisica, Quimica e Biologia

    2005-07-01

    Agronomic Institute (IAC) and EMBRAPA Agricultural Instrumentation (EMBRAPA/CNPDIA) have been studied Hevea species in order to increase the production of the natural rubber and to develop new clones more appropriated to Brazil's soil and climate. Structural characterization of natural rubber [Hevea brasiliensis (Willd. ex Adr. de Juss.) Muell. - Arg.] from new clones of the IAC series (IAC 300, 301, 302, 303, 35, 40, and 56) and from RRIM 600 clone has been studied by high-resolution solid-state {sup 13}C NMR and by single pulse technique. The results have shown that the application of solid-state {sup 13}C NMR using the single pulse technique is a powerful tool to study natural rubber. The spectra obtained through this technique confirmed that natural rubber from all clones studied are cis-1,4-polyisoprene (author) form.(author)

  1. QENS investigation of filled rubbers

    CERN Document Server

    Triolo, A; Desmedt, A; Pieper, J K; Lo Celso, F; Triolo, R; Negroni, F; Arrighi, V; Qian, H; Frick, B

    2002-01-01

    The polymer segmental dynamics is investigated in a series of silica-filled rubbers. The presence of inert fillers in polymers greatly affects the mechanical and physical performance of the final materials. For example, silica has been proposed as a reinforcing agent of elastomers in tire production. Results from quasielastic neutron scattering and Dynamic Mechanical Thermal Analysis (DMTA) measurements are presented on styrene-ran-butadiene rubber filled with silica. A clear indication is obtained of the existence of a bimodal dynamics, which can be rationalized in terms of the relaxation of bulk rubber and the much slower relaxation of the rubber adsorbed on the filler surface. (orig.)

  2. Effect of molecular weight and testing rate on adhesion property of pressure-sensitive adhesives prepared from epoxidized natural rubber

    International Nuclear Information System (INIS)

    Khan, Imran; Poh, B.T.

    2011-01-01

    Research highlights: → Elucidation of adhesion property of epoxidized natural rubber (ENR 25). → Correlation of peel and shear strength with molecular weight and rate of testing. → Confirmation of miscibility of tackifier and ENR 25 by DSC and FTIR study. → Applicability of Fox equation in ENR 25/coumarone-indene resin system. -- Abstract: The dependence of peel strength and shear strength of epoxidized natural rubber (ENR 25)-based pressure-sensitive adhesive on molecular weight and rate of testing was investigated using coumarone-indene as the tackifying resin. Toluene and polyethylene terephthalate (PET) were used as the solvent and substrate respectively throughout the study. A SHEEN hand coater was used to coat the adhesive on the substrate at a coating thickness of 120 μm. All the adhesion properties were determined by a Llyod Adhesion Tester operating at different rates of testing. Result shows that peel strength and shear strength increases up to an optimum molecular weight of 6.5 x 10 4 of ENR 25. For peel strength, the observation is attributed to the combined effects of wettability and mechanical strength of rubber at the optimum molecular weight, whereas for the shear strength, it is ascribed to the increasing amount of adhesive present in the coating layer which enhances the shear resistance of the adhesive. Peel strength and shear strength also increases with increase in rate of testing, an observation which is associated to the viscoeslastic response of the adhesive. Differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) study confirms the miscibility of tackifier and the ENR 25.

  3. Effect of epoxidation level on thermal properties and ionic conductivity of epoxidized natural rubber solid polymer nanocomposite electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Harun, Fatin; Chan, Chin Han; Winie, Tan [Faculty of Applied Sciences, UniversitiTeknologi MARA (UiTM), Shah Alam, 40450 Selangor Darul Ehsan (Malaysia); Sim, Lai Har; Zainal, Nurul Fatahah Asyqin [Center of Foundation Studies, PuncakAlam Campus, UniversitiTeknologi MARA, 40430 Selangor Darul Ehsan (Malaysia)

    2015-08-28

    Effect of epoxide content on the thermal and conductivity properties of epoxidized natural rubber (ENR) solid polymer nanocomposite electrolytes was investigated. Commercial available epoxidized natural rubber having 25 (ENR25) and 50 mole% (ENR50) epoxide, respectively were incorporated with lithium perchlorate (LiClO{sub 4}) salt and titanium dioxide (TiO{sub 2}) nanofiller via solution casting method. The solid polymer nanocomposite electrolytes were characterized by differential scanning calorimetry (DSC) and impedance spectroscopy (IS) for their thermal properties and conductivity, respectively. It was evident that introduction of LiClO{sub 4} causes a greater increase in glass transition temperature (T{sub g}) and ionic conductivity of ENR50 as compared to ENR25. Upon addition of TiO{sub 2} in ENR/LiClO{sub 4} system, a remarkable T{sub g} elevation was observed for both ENRs where ENR50 reveals a more pronounced changes. It is interesting to note that they exhibit different phenomenon in ionic conductivity with TiO{sub 2} loading where ENR25 shows enhancement of conductivity while ENR50 shows declination.

  4. Production Of Hollow Toy Product From Radiation Pre vulcanized Natural Rubber Latex (RVNRL) By Using Casting And Moulding Technique

    International Nuclear Information System (INIS)

    Mohd Noorwadi Mat Lazim; Sofian Ibrahim; Muhammad Saiful Omar

    2013-01-01

    Hollow toy products are very synonym to the child from the age of months since it able to stimulating each of their sense such as sight, hearing, taste, touch and smell. Most of hollow toy products are made from natural rubber latex by using moulding and casting technique. The moulding and casting technique is a manufacturing process by pored liquid latex into a mould, which contain cavity of the desired shape. The mould made from plaster of Paris able to absorbs water from latex meanwhile the presence of calcium ions from plaster of Paris will tend to diffuse into latex thus promote formation of deposit on surface of cavity mould. To improve the quality and safety of hollow toy product made from latex, Radiation Pre vulcanized Natural Rubber Latex (RVNRL) has been identified to be used because it can fulfill the standard requirement for latex and also due to its special abilities such as lower modulus (soft latex products), nitrosamines free, low in nitrosatables, free from chemical accelerators induced allergies and better biodegradability. This paper identify the problem appears from the process of making hollow toy products from RVNRL by using moulding and casting technique. (author)

  5. Tensile and morphology properties of PLA/LNR blends modified with maleic anhydride grafted-polylactic acid and -natural rubber

    Science.gov (United States)

    Ruf, Mohd Farid Hakim Mohd; Ahmad, Sahrim; Chen, Ruey Shan; Shahdan, Dalila; Zailan, Farrah Diyana

    2018-04-01

    This research was carried out to investigate the addition of grafted copolymers of maleic anhydride grafted-polylactic acid(PLA-g-MA) and maleic anhydride grafted-natural rubber (NR-g-MA) on the tensile and morphology properties of polylactic acid/ liquid natural rubber (PLA/LNR) blends. Prior to blend preparation, the PLA-g-MA and NR-g-MA was first self-synthesized using maleic anhydride (MA) and dicumyl peroxide (DCP) as initiator together with the PLA and NR respectively. The PLA/LNR, PLA/LNR/PLA-g-MA and PLA/LNR/NR-g-MA blends were prepared via melt-blending method. The loading of PLA-g-MA and NR-g-MA was varied by 5, 10 and 15 wt% respectively. The addition of PLA-g-MA led to increment in tensile strength with 5 and 10 wt% while NR-g-MA gives lower than controlled sample (PLA/LNR blend). Scanning electron microscope (SEM) showed the interaction of the components in the blends. The PLA/LNR compatibilized with PLA-g-MA and NR-g-MA shows greater dispersion and adhesion.

  6. Developments in rubber technology 2 synthetic rubbers

    CERN Document Server

    Lee, K

    1981-01-01

    This book is intended for those people who have a knowledge or understanding of rubber materials and processes but who wish to update their knowledge. It should be read in conjunction with Developments in Rubber Technology-l as that volume discussed developments in natural rubber and selected special purpose synthetic rubbers as well as additives. The authors have been selected for their expertise in each particular field and we, as editors, would like to express our appreciation to the individual authors and also to their companies. Such a book would be impossible to produce without such active cooperation as we have received. Volumes 1 and 2 of Developments in Rubber Technology cover rubbers which are processed and vulcanised in the traditional manner. It is appreciated that the omission of non-vulcanised rubber materials (the so­ called thermoplastic elastomers) will be unwelcome to many readers but it is intended, because of the size of the subject, to cover these materials in a subsequent volume. A.W. K...

  7. FTIR spectra and mechanical strength analysis of some selected rubber derivatives

    Science.gov (United States)

    Gunasekaran, S.; Natarajan, R. K.; Kala, A.

    2007-10-01

    Rubber materials have wide range of commercial applications such as, infant diapers, famine hygiene products, drug delivery devices and incontinency products such as rubber tubes, tyres, etc. In the present work, studies on mechanical properties of some selected rubber materials viz., natural rubber (NR), styrene butadiene rubber (SBR), nitrile butadiene rubber (NBR) and ethylene propylene diene monomer (EPDM) have been carried out in three states viz., raw, vulcanized and reinforced. To enhance the quality of rubber elastomers, an attempt is made to prepare new elastomers called polyblends. In the present study an attempt is made to blend NR with NBR and with EPDM. We here report, a novel approach for the evaluation of various physico-mechanical properties such as mechanical strength, tensile strength, elongation and hardness. The method is simple, direct and fast and involves infrared spectral measurements for the evaluation of these properties. With the applications of modern infrared spectroscopy, the mechanical strength of these rubber materials have been analyzed by calculating the internal standards among the methyl and methylene group vibrational frequencies obtained from FTIR spectroscopy. Also the tensile strength measurements carried out by universal testing machine. The results pertaining physico-mechanical properties of the rubber derivatives undertaken in the present study obtained by IR-based method are in good agreement with data resulted from the standard methods.

  8. Solubility Study of Curatives in Various Rubbers

    NARCIS (Netherlands)

    Guo, R.; Talma, Auke; Datta, Rabin; Dierkes, Wilma K.; Noordermeer, Jacobus W.M.

    2008-01-01

    The previous works on solubility of curatives in rubbers were mainly carried out in natural rubber. Not too much information available on dissimilar rubbers and this is important because most of the compounds today are blends of dissimilar rubbers. Although solubility can be expected to certain

  9. Rubber molds for investment casting

    International Nuclear Information System (INIS)

    Sibtain, S.N.

    2011-01-01

    The main objective of the project is to investigate different types of molding rubbers used for investment casting. The level of shape complexity which can be achieved by using these rubber molds is also studied. It was almost impossible to make complex shapes molds using metal molds, in that cases rubber molds are very important because they arc flexible and give accurate and precise part dimensions. Turbine blades are hi-tech components with air-foil geometries that have close dimensional tolerances. They are made of super-alloys and manufactured by investment casting. The final blade profile depends upon the dimensional accuracy in each of the processing steps. In the present work experimental study for the production of high quality low cost castings of turbine blades using rubber molds and injected wax patterns is presented. Natural Rubber molds and wax patterns from these molds were made. Different types of molding rubbers were studied including natural rubber, silicone rubber and liquid silicone rubber. It was found that by using rubber molds we can make most complex shape with very less finishing required. The shrinkage was 12% as compared to original master pattern. Rubber molds were made using laboratory hot press. Three layers of rubber above and below the master pattern. After that vulcanization was done by giving temperature and pressure. (author)

  10. On the nature of surface roughness with application to contact mechanics, sealing, rubber friction and adhesion

    International Nuclear Information System (INIS)

    Persson, B N J; Albohr, O; Tartaglino, U; Volokitin, A I; Tosatti, E

    2005-01-01

    Surface roughness has a huge impact on many important phenomena. The most important property of rough surfaces is the surface roughness power spectrum C(q). We present surface roughness power spectra of many surfaces of practical importance, obtained from the surface height profile measured using optical methods and the atomic force microscope. We show how the power spectrum determines the contact area between two solids. We also present applications to sealing, rubber friction and adhesion for rough surfaces, where the power spectrum enters as an important input. (topical review)

  11. Effect of Molecular Weight on the Properties of Liquid Epoxidized Natural Rubber Acrylate (LENRA)/ Silica Hybrid Composites

    International Nuclear Information System (INIS)

    Eda Yuhana Ariffin; Azizan Ahmad; Dahlan Mohd; Mahathir Mohamed

    2011-01-01

    This paper reports on the effect of molecular weight on the morphological and mechanical properties of liquid epoxidized natural rubber acrylate (LENRA)/ silica hybrid composites prepared by sol-gel technique. The sol-gel reaction was conducted at different concentration of tetraethyl orthosilicate (TEOS), used as a precursor of silica. TEOS were introduced in 10, 20, 30, 40 and 50 parts per hundred rubber (phr) in the composites. Two different molecular weights of ENR were used to study the effect of molecular weight on the mechanical and morphological properties of the compounds. These compounds were cured by ultraviolet (UV) irradiation. The mechanical properties were studied through pendulum hardness and scratch tests. Higher molecular weight of ENR showed better mechanical properties than lower molecular weight. Transmission electron microscope was used to determine the silica size and to study the distribution and dispersion of the silica particles. High molecular weight showed greater distribution and dispersion of silica particles with diameter of 13 - 256 nm. Morphological and mechanical properties of LENRA/ silica hybrid composites were improved by using high molecular weight of ENR. (author)

  12. Performance of sand and shredded rubber tire mixture as a natural base isolator for earthquake protection

    Science.gov (United States)

    Bandyopadhyay, Srijit; Sengupta, Aniruddha; Reddy, G. R.

    2015-12-01

    The performance of a well-designed layer of sand, and composites like layer of sand mixed with shredded rubber tire (RSM) as low cost base isolators, is studied in shake table tests in the laboratory. The building foundation is modeled by a 200 mm by 200 mm and 40 mm thick rigid plexi-glass block. The block is placed in the middle of a 1m by 1m tank filled with sand. The selected base isolator is placed between the block and the sand foundation. Accelerometers are placed on top of the footing and foundation sand layer. The displacement of the footing is also measured by LVDT. The whole setup is mounted on a shake table and subjected to sinusoidal motions with varying amplitude and frequency. Sand is found to be effective only at very high amplitude (> 0.65 g) of motions. The performance of a composite consisting of sand and 50% shredded rubber tire placed under the footing is found to be most promising as a low-cost effective base isolator.

  13. Type I allergy to natural rubber latex and type IV allergy to rubber chemicals in health care workers with glove-related skin symptoms.

    Science.gov (United States)

    Nettis, E; Assennato, G; Ferrannini, A; Tursi, A

    2002-03-01

    It has been established that there are type I and type IV allergens in latex gloves. The purpose of the study was to establish the prevalence of rubber glove-induced skin symptoms among health care workers in one Italian hospital. Health care workers (n = 1584) were evaluated using a written questionnaire and 295 respondents with glove-induced skin symptoms were tested. We performed: skin prick test with latex glove extract and commercial latex, and environmental and food allergens; glove use test; patch tests with a rubber additive series; and RASTs. Hospital employees who used or had used latex gloves at work were 1294. Three hundred and sixteen (24.4%) reported glove-induced symptoms, namely, cutaneous symptoms in all the cases and non-cutaneous symptoms in 105 subjects (8.1%). Twenty-seven of the 295 symptomatic employees tested (9.1%) were latex sensitive. Thirty-one patients (10.5%) exhibited positive patch test to rubber-related allergens. The most positive readings were obtained from the Thiuram mix and the Carba mix, with 12 and 9 positivities, respectively. The risk factors for latex skin sensitization were: a previous history of atopy and asthma; history of surgery; pre-existing hand dermatitis; work-related symptoms; and positive skin tests to common inhalant and certain foods (P skin complaints of latex gloves are related to skin irritation rather than to allergy. The immediate allergy to latex and the delayed allergy to rubber chemicals suggest that all the health care workers with glove-related dermatitis should undergo both skin prick test and glove use test to detect type I hypersensitivity to latex, and patch test to detect type IV hypersensitivity to rubber chemicals.

  14. New Insights into the Relationship Between Network Structure and Strain Induced Crystallization in Unvolcanized Natural Rubber by Synchrotron X-ray Diffraction

    International Nuclear Information System (INIS)

    Toki, S.; Hsiao, B.; Amnuaypornsri, S.; Sakdapipanich, J.

    2009-01-01

    The relationship between the network structure and strain-induced crystallization in un-vulcanized as well as vulcanized natural rubbers (NR) and synthetic poly-isoprene rubbers (IR) was investigated via synchrotron wide-angle X-ray diffraction (WAXD) technique. It was found that the presence of a naturally occurring network structure formed by natural components in un-vulcanized NR significantly facilitates strain-induced crystallization and enhances modulus and tensile strength. The stress-strain relation in vulcanized NR is due to the combined effect of chemical and naturally occurring networks. The weakness of naturally occurring network against stress and temperature suggests that vulcanized NR has additional relaxation mechanism due to naturally occurring network. The superior mechanical properties in NR compared with IR are mainly due to the existence of naturally occurring network structure.

  15. Mechanical Enhancement of Sensitivity in Natural Rubber Using Electrolytic Polymerization Aided by a Magnetic Field and MCF for Application in Haptic Sensors.

    Science.gov (United States)

    Shimada, Kunio; Saga, Norihiko

    2016-09-18

    Sensors are essential to the fulfillment of every condition of haptic technology, and they need simultaneously to sense shear stress as well as normal force, and temperature. They also must have a strong and simple structure, softness, and large extension. To achieve these conditions simultaneously, we enhanced the sensitivity of sensors utilizing natural rubber (NR)-latex through the application of electrolytic polymerization focused on the isoprene C=C bonds in natural rubbers such as NR-latex, and then applied a magnetic field and magnetic compound fluid (MCF) as magnetically responsive fluid. When an electric field alone was used in the rubber, the effect of electrolytic polymerization was very small compared to the effect in well-known conductive polymer solution such as plastic. The MCF developed by Shimada in 2001 involved magnetite and metal particles, and acts as a filler in NR-latex. By utilizing the magnetic, electric fields and the MCF, we aligned the electrolytically polymerized C=C along the magnetic field line with the magnetic clusters formed by the aggregation of magnetite and metal particles so as to enhance the effect of electrolytic polymerization. We then demonstrated the effectiveness of the new method of rubber vulcanization on the sensitivity of the rubber by experimentally investigating its electric and dynamic characteristics.

  16. Mechanical Enhancement of Sensitivity in Natural Rubber Using Electrolytic Polymerization Aided by a Magnetic Field and MCF for Application in Haptic Sensors

    Directory of Open Access Journals (Sweden)

    Kunio Shimada

    2016-09-01

    Full Text Available Sensors are essential to the fulfillment of every condition of haptic technology, and they need simultaneously to sense shear stress as well as normal force, and temperature. They also must have a strong and simple structure, softness, and large extension. To achieve these conditions simultaneously, we enhanced the sensitivity of sensors utilizing natural rubber (NR-latex through the application of electrolytic polymerization focused on the isoprene C=C bonds in natural rubbers such as NR-latex, and then applied a magnetic field and magnetic compound fluid (MCF as magnetically responsive fluid. When an electric field alone was used in the rubber, the effect of electrolytic polymerization was very small compared to the effect in well-known conductive polymer solution such as plastic. The MCF developed by Shimada in 2001 involved magnetite and metal particles, and acts as a filler in NR-latex. By utilizing the magnetic, electric fields and the MCF, we aligned the electrolytically polymerized C=C along the magnetic field line with the magnetic clusters formed by the aggregation of magnetite and metal particles so as to enhance the effect of electrolytic polymerization. We then demonstrated the effectiveness of the new method of rubber vulcanization on the sensitivity of the rubber by experimentally investigating its electric and dynamic characteristics.

  17. An experimental study of mechanical behavior of natural fiber reinforced polymer matrix composites

    Science.gov (United States)

    Ratna, Sanatan; Misra, Sheelam

    2018-05-01

    Fibre-reinforced polymer composites have played a dominant role for a long time in a variety of applications for their high specific strength and modulus. The fibre which serves as a reinforcement in reinforced plastics may be synthetic or natural. Past studies show that only synthetic fibres such as glass, carbon etc., have been used in fibre reinforced plastics. Although glass and other synthetic fibre-reinforced plastics possess high specific strength, their fields of application are very limited because of their inherent higher cost of production. In this connection, an investigation has been carried out to make use of horse hair, an animal fibre abundantly available in India. Animal fibres are not only strong and lightweight but also relatively very cheaper than mineral fibre. The present work describes the development and characterization of a new set of animal fiber based polymer composites consisting of horse hair as reinforcement and epoxy resin. The newly developed composites are characterized with respect to their mechanical characteristics. Experiments are carried out to study the effect of fibre length on mechanical behavior of these epoxy based polymer composites. Composite made form horse hair can be used as a potential reinforcing material for many structural and non-structural applications. This work can be further extended to study other aspects of such composites like effect of fiber content, loading pattern, fibre treatment on mechanical behavior of horse hair based polymer horse hair.

  18. Investigation on dielectric relaxation of PMMA-grafted natural rubber incorporated with LiCF3SO3

    International Nuclear Information System (INIS)

    Yap, K.S.; Teo, L.P.; Sim, L.N.; Majid, S.R.; Arof, A.K.

    2012-01-01

    Natural rubber (NR) grafted with 30 wt% poly (methyl methacrylate) (PMMA) and designated as MG30 has been added with varying amounts of LiCF 3 SO 3 . X-ray diffraction (XRD) shows the samples to be amorphous. Fourier transform infrared (FTIR) spectroscopy indicates complexation between the cation of the salt and the oxygen atom of the C=O and -COO- groups of MG30. From electrochemical impedance spectroscopy (EIS), MG30 with 30 wt% LiCF 3 SO 3 salt exhibits the highest ambient conductivity of 1.69×10 -6 S cm -1 and lowest activation energy of 0.24 eV. The dielectric behavior has been analyzed using dielectric permittivity (ε′), dissipation factor (tan δ) and dielectric modulus (M ⁎ ) of the samples. The dielectric constant of pure MG30 has been estimated to be ∼1.86.

  19. Combination of Tung oil and Natural Rubber Latex in PVA as Water Based Coatings for Paperboard Application

    Directory of Open Access Journals (Sweden)

    Jianprasert Apichaya

    2015-01-01

    Full Text Available This research is focused on the preparation of the PVA/TO/NRL coatings for paperboard by using poly(vinyl alcohol (PVA as substance and blending with Tung oil (TO and/or natural rubber latex (NRL in order to enhance water resistance and dynamic mechanical properties. The effects of TO: NRL ratios on the structures were investigated by water resistance property and dynamic mechanical thermal analysis (DMA. The results showed that the water resistance property was improved by crosslinking of TO and film forming of NRL. The PVA/TO/NRL coating containing both TO and NRL gave better thermal behavior than those with only TO or NRL. For paperboard application, the PVA/TO/NRL coatings were applied on the paperboard to study water affinity and absorption rate on the coated surface. The rate of contact angle change of water on coated paperboards decreased depending on the ratios of TO and NRL.

  20. Effect of various cross-linking types on the physical properties in carbon black-filled natural rubber compound

    Energy Technology Data Exchange (ETDEWEB)

    Park, B.H.; Jung, I.G.; Park, S.S. [Kumho Industry Co., Kwangju (Korea)

    2001-01-01

    The objective of this study was to investigate the effect of cure type on the processing and physical properties under conditions of similar stress-strain properties. On the carbon black filled natural rubber (NR) based compound, the induction time decreased, but the cure rate became fast with increasing loading of sulfur donor agent. Tensile strength was little affected on the curing type. However, elongation generally decreased with increasing accelerator. Effect of cure type on the blow-out properties was followings: CV[semi-EV][EV][hybrid bond][resin cure]. Version 1 and version 4 exhibited good cutting and chipping resistance compared to other cure systems. Especially, compounds with KA-9188 exhibited processing stability, good reversion and blow-out property without sacrificing tensile properties. It implies that sulfur cure system can be replaced with hybrid-cure system. (author). 9 refs., 6 tabs., 7 figs.

  1. Study on wood vinegars for use as coagulating and antifungal agents on the production of natural rubber sheets

    Energy Technology Data Exchange (ETDEWEB)

    Baimark, Yodthong; Niamsa, Noi [Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Mahasarakham University, Mahasarakham 44150 (Thailand)

    2009-06-15

    Coagulating and antifungal properties of wood vinegars in the preparation process of Hevea brasiliensis natural rubber (NR) sheets were investigated and compared with those of formic and acetic acids. The wood vinegars produced from biomasses such as inner coconut shell, bamboo and Eucalyptus woods were evaluated. It was found that plasticity retention index, Mooney viscosity and mechanical properties of NR coagulated by wood vinegars were similar to those using acetic acid and better than using formic acid. The antifungal efficiency of coagulants determined from a fungi growth area on NR sheet surfaces was found in the following order: coconut shell wood vinegar > bamboo wood vinegar {approx} Eucalyptus wood vinegar > acetic acid {approx} formic acid. The antifungal efficiency of the wood vinegars was strongly depended upon their phenolic compound contents and confirmed through the inhibitory growth of the main fungi, Penicillium griseofulvum, on potato dextrose agar. (author)

  2. Toxicological evaluation of natural rubber films from vulcanized latex by the conventional process and the alternative process with ionizing radiation

    International Nuclear Information System (INIS)

    Campos, Vania Elisabeth

    1997-01-01

    The industrial vulcanization of natural rubber latex (NRL) is made all over the world by conventional process using sulphur and heat but it can be made by an alternative process using ionizing radiation. In this research the NRL was tested by 13 physical, chemical and mechanical assays which showed its good quality. It was done a preliminary study of the toxicological properties of 4 natural rubber films obtained by casting process of NRL: one non vulcanized, other vulcanized by the conventional process and two vulcanized by the alternative process. In the alternative process the films were obtained by irradiation of NRL by gamma rays from the 60 Co source at 250 kGy in the absence of sensitizer and irradiated NRL at 12 kGy in the presence of 4ph r of n-butyl acrylate / 0.2 phr of KOH. These vulcanization doses were determined from broken tensile strength. In the conventional process, sulphur vulcanized NRL was made using a classical composition. Another film was made with non vulcanized NRL. The preliminary evaluation of the toxicological properties was made from in vitro cytotoxicity and in vivo systemic toxicity assays. The LBN films vulcanized by the alternative process have less cytotoxicity than the NRL film vulcanized by the conventional process. The sensitized vulcanized films by gamma rays and non vulcanized films showed similar cytotoxicity while the vulcanized films without sensitizer showed a slight lower cytotoxicity. The non vulcanized NRL film and the NRL films vulcanized by the alternative process did not show toxic effects int he 72 hours period of the systemic toxicity assay. However the NRL film vulcanized with sulphur induced effects like allaying and motor in coordination on the animals treated with an oil extract at the fourth hour and recovering after that. The alternative process promoted lower toxic effects than conventional process because there was no toxic substances present. (author)

  3. Chitosan composite hydrogels reinforced with natural clay nanotubes.

    Science.gov (United States)

    Huang, Biao; Liu, Mingxian; Zhou, Changren

    2017-11-01

    Here, chitosan composites hydrogels were prepared by addition of halloysite nanotubes (HNTs) in the chitosan KOH/LiOH/urea solution. The raw chitosan and chitosan/HNTs composite hydrogels were obtained by heat treatment at 60°C for 8h and then regeneration in ethanol solution. The viscosity of the composite solution is increased with HNTs content. The Fourier transform infrared spectroscopy (FT-IR) shows that the hydrogen bonds interactions exist between the HNTs and the chitosan. X-ray diffraction (XRD) results show that the crystal structure of HNT is not changed in the composite hydrogels. The compressive property test and storage modulus determination show that the mechanical properties and anti-deformation ability of the composite hydrogel significantly increase owing to the reinforcing effect of HNTs. The composites hydrogel with 66.7% HNTs can undergo 7 times compression cycles without breaking with compressive strength of 0.71MPa at 70% deformation, while pure chitosan hydrogel is broken after bearing 5 compression cycles with compressive strength of 0.14MPa and a maximum deformation of 59%. A porous structure with pore size of 100-500μm is found in the composite hydrogels by scanning electron microscopy (SEM), and the pore size and the swelling ratio in NaCl solution decrease by the addition of HNTs and the immersing of ethanol. Chitosan/HNTs composite hydrogels show low cytotoxicity towards MC3T3-E1 cells. Also, the composite hydrogels show a maximum drug entrapment efficiency of 45.7% for doxorubicin (DOX) which is much higher than that of pure chitosan hydrogel (27.5%). All the results illustrate that the chitosan/HNTs composite hydrogels show promising applications as biomaterials. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Melt rheological properties of natural fiber-reinforced polypropylene

    Science.gov (United States)

    Jarrod J. Schemenauer; Tim A. Osswald; Anand R. Sanadi; Daniel F. Caulfield

    2000-01-01

    The melt viscosities and mechanical properties of 3 different natural fiber-polypropylene composites were investigated. Coir (coconut), jute, and kenaf fibers were compounded with polypropylene at 30% by weight content. A capillary rheometer was used to evaluate melt viscosity. The power-law model parameters are reported over a shear rate range between 100 to 1000 s–1...

  5. Epoxidação "in situ" aplicada ao látex de borracha natural "In situ" epoxidation of natural rubber latex

    Directory of Open Access Journals (Sweden)

    Cristiane K. Santin

    2012-01-01

    Full Text Available O comportamento da borracha natural na forma látex frente à reação de epoxidação foi avaliado visando estabelecer as melhores condições reacionais sem a ocorrência de reações laterais, que promovem a coagulação do látex e o desenvolvimento de um aglomerado de borracha. Grupos epóxidos foram gerados através da reação de epoxidação a partir da formação in situ do ácido perfórmico. As amostras foram caracterizadas qualitativamente por espectroscopia de infravermelho (FTIR e o grau de modificação determinado por ressonância magnética nuclear de hidrogênio (1H-RMN. Análises de calorimetria exploratória diferencial (DSC demonstraram que a mobilidade da cadeia polimérica foi influenciada pela presença de grupos epóxidos, com aumento linear na temperatura de transição vítrea (Tg. Os resultados indicaram que a epoxidação do látex de borracha natural, sem a ocorrência de reações laterais, é possível e dependente das condições reacionais.Natural rubber latex was submitted to epoxidation reaction to establish the best reaction conditions without the occurrence of side reactions, which promote coagulation of the latex and development of an agglomerate of rubber. Epoxy groups were produced by in situ epoxidation with formic acid and hydrogen peroxide. The samples were characterized qualitatively by Fourier Transform Infrared (FTIR analysis and the degree of modification determined by Hydrogen Nuclear Magnetic Resonance Spectroscopy (1H-NMR analysis. A linear increase in the glass transition temperature (Tg was observed. The results show that the epoxidation of natural rubber latex is possible and depends on the reaction conditions.

  6. Impact test on natural fiber reinforced polymer composite materials

    Directory of Open Access Journals (Sweden)

    D. Chandramohan

    2013-06-01

    Full Text Available In this research, natural fibers like Sisal (Agave sisalana, Banana (Musa sepientum & Roselle (Hibiscus sabdariffa , Sisal and banana (hybrid , Roselle and banana (hybrid and Roselle and sisal (hybrid are fabricated with bio epoxy resin using molding method. In this work, impact strength of Sisal and banana (hybrid, Roselle and banana (hybridand Roselle and sisal (hybrid composite at dry and wet conditions were studied. Impact test were conducted izod impact testing machine. In this work micro structure of the specimens are scanned by the Scanning Electron Microscope.

  7. Multilayer graphene rubber nanocomposites

    Science.gov (United States)

    Schartel, Bernhard; Frasca, Daniele; Schulze, Dietmar; Wachtendorf, Volker; Krafft, Bernd; Morys, Michael; Böhning, Martin; Rybak, Thomas

    2016-05-01

    Multilayer Graphene (MLG), a nanoparticle with a specific surface of BET = 250 m2/g and thus made of only approximately 10 graphene sheets, is proposed as a nanofiller for rubbers. When homogenously dispersed, it works at low loadings enabling the replacement of carbon black (CB), increase in efficiency, or reduction in filler concentration. Actually the appropriate preparation yielded nanocomposites in which just 3 phr are sufficient to significantly improve the rheological, curing and mechanical properties of different rubbers, as shown for Chlorine-Isobutylene-Isoprene Rubber (CIIR), Nitrile-Butadiene Rubber (NBR), Natural Rubber (NR), and Styrene-Butadiene Rubber (SBR). A mere 3 phr of MLG tripled the Young's modulus of CIIR, an effect equivalent to 20 phr of carbon black. Similar equivalents are observed for MLG/CB mixtures. MLG reduces gas permeability, increases thermal and electrical conductivities, and retards fire behavior. The later shown by the reduction in heat release rate in the cone calorimeter. The higher the nanofiller concentration is (3 phr, 5 phr, and 10 phr was investigated), the greater the improvement in the properties of the nanocomposites. Moreover, the MLG nanocomposites improve stability of mechanical properties against weathering. An increase in UV-absorption as well as a pronounced radical scavenging are proposed and were proved experimentally. To sum up, MLG is interesting as a multifunctional nanofiller and seems to be quite ready for rubber development.

  8. The Effects of Trans- Polyoctylene Rubber (TOR as a Compatibilizer on The Properties of Epoxidized Natural Rubber/Recycled Silicone Catheter (ENR-25/rSC Vulcanizate

    Directory of Open Access Journals (Sweden)

    Dahham Omar S.

    2016-01-01

    Full Text Available In this study, the influence of Trans- Polyoctylene Rubber (TOR as a compatibilizer on the cure characteristics, tensile and physical properties of ENR-25/rSC vulcanizate were determined. Five different loading of TOR (2, 4, 6, 8 and 10 phr were prepared and added into the vulcanizate. Results indicated that the scorch time (t2 and cure time (t90 bacame shorter as TOR increased, while minimum torque (ML and maximum torque (MH increased. The incorporation of TOR with the vulcanizates enhanced the tensile strength (Ts, modulus (M100 crosslinking density and hardness values. However, the elongation at break percentage of compatibilized vulcanizates became lower than uncompatibilized vulcanizates.

  9. Characterizing Response-Reinforcer Relations in the Natural Environment: Exploratory Matching Analyses

    Science.gov (United States)

    Sy, Jolene R.; Borrero, John C.; Borrero, Carrie S. W.

    2010-01-01

    We assessed problem and appropriate behavior in the natural environment from a matching perspective. Problem and appropriate behavior were conceptualized as concurrently available responses, the occurrence of which was thought to be determined by the relative rates or durations of reinforcement. We also assessed whether response allocation could…

  10. Laboratory Investigation on the Effects of Natural Fine Aggregates and Recycled Waste Tire Rubber in Pervious Concrete to Develop More Sustainable Pavement Materials

    Science.gov (United States)

    Bonicelli, Alessandra; Fuentes, Luis G.; Khalil Dawd Bermejo, Ibrahim

    2017-10-01

    Pervious concrete pavement is a recognized sustainable solution for urban roads. To enhance mechanical properties of pervious concrete material, in order to allow wider use of this technology, a lot of studies are going on all over the world. The use of a little percentage of fine aggregates is proven to increase the material resistance without an excessive reduction of permeability. This study aimed to evaluate the effect of replacing the fine virgin aggregates with r cycled tire rubber. 14 different mixes were analysed in terms of indirect tensile strength resistance, void content and density. Two different dimensions of crumb rubber were studied, as well as two different dosages, which were applied to different no-fine control mixes. All results were compared with the same control mixes containing natural fine aggregate. The mixes had a fixed granulometric curve but varied in water/cement ratio; this in order to evaluate the effect of recycled rubber depending to w/c ratio of the mix. An image analysis was also conducted to verify the rubber distribution in the mixture and the cracking surfaces. The experimental analysis showed that a correct proportioning of fine sand significantly increased the strength of the material. Moreover, the use of recycled waste tire rubber, gave interesting improvements respect to the no-fine control mixes, even though the developed resistance was lower respect to mixes containing mineral sand. This result was expected because of the cementing property of mineral sand. Although, the important result was that it was possible to use waste tire rubber in pervious concrete, with an appropriate dosage and granular dimension, for increasing the performance of traditional mix design, in order to achieve pavement materials more and more sustainable.

  11. Rubber mixing process and its relationship with bound rubber and crosslink density

    Science.gov (United States)

    Hasan, A.; Rochmadi; Sulistyo, H.; Honggokusumo, S.

    2017-06-01

    This research studied the relationship between bound rubber and crosslink density based on rubber mixing process. Bound rubber was obtained after natural rubber was masticated and mixed with rubber chemicals and filler while crosslink density was collected after rubber compound was vulcanized. Four methods are used and each method refers to four ways of incorporating carbon black during mixing. The first method, after rubber was masticated for 5 minutes, the addition of rubber chemicals and filler was done simultaneously. Rubber was masticated for 1 minute and continued mixing of rubber chemicals and filler where mixing was different from first method. This was the second method. The third method was the same as the second method but the filler used N 660 while in the second method N 330. The last method is not the same as the first and second, the rubber is only masticated for 3 minutes and then mixed with filler and followed by rubber chemicals sequentially. The results showed that bound rubber and crosslink density were influenced by mixing and mastication process. Bound rubber dropped and crosslink density was relatively stable in the first three mixing methods for increasing carbon black at the beginning of the mixing process. Bound rubber and crosslink density stated opposite results in the fourth mixing method. The higher the bound rubber the lower the crosslink density. Without regard to mixing methods, there is a non-linear relationship between bound rubber formation and crosslink density determination

  12. Synthesis and characterization of polymeric composites reinforced natural fiber

    International Nuclear Information System (INIS)

    Kartini, Ratni; Darmasetiawan, H.; Karo Karo, Aloma; Sudirman

    2002-01-01

    Synthesis of composites between the polymeric matrixes i.e. epoxy and polyester with the natural fibers i.e. banana and straw fibers have been done, which combined each other into four kinds of composites i.e. epoxy-banana, epoxy-straw, polyester-banana, and polyester-straw composites. For each kind of composites, the effect of fibers layers addition into the polymeric matrixes on its mechanical and its microstructure, were learned. It is found that, for all composites except for epoxy-straw, this effect made their tensile strength to be decrease. Epoxy -3-layers straw fibers composite has the highest value that is 45.44 MPa while epoxy -3-layers banana fibers composite has 30.47 MPa for its tensile strength. The lowest tensile strength was belong to polyester -3-layers banana fibers composite, and if it was filled with 3-layers of straw fibers that value become increase to reach 22.18 MPa. Unfortunately, the effect of fibers layer addition is also made their hardness become decrease. It was showed from their microstructures that there were weak bonds between fibers and matrixes. Besides that reason, it also known that fibers distribution in matrixes influences both the tensile strength and the hardness of composite

  13. Análise econométrica da demanda brasileira de importação de borracha natural, de 1964 a 2005 Econometric analysis of Brazilian import demand for natural rubber during 1964-2005

    Directory of Open Access Journals (Sweden)

    Naisy Silva Soares

    2008-12-01

    Full Text Available Este trabalho teve por objetivos especificar e estimar a demanda brasileira de importação de borracha natural, no período de 1964 a 2005. As variáveis explicativas do modelo de demanda de importação foram: preço de importação da borracha natural, PIB per capita, taxa de câmbio, taxa de juros, quantidade de borracha natural produzida internamente e tendência. As estimativas obtidas utilizando o modelo de ajustamento parcial confirmaram que as variáveis explicativas afetam, significativamente, a demanda brasileira de importação de borracha natural. Os resultados apontaram que a demanda brasileira de importação de borracha natural é inelástica com relação ao preço de importação e à renda; é pouco sensível a variações no preço de importação, à taxa de câmbio, à renda e à taxa de juros, mas é sensível às variações na quantidade de borracha natural produzida internamente, no curto e longo prazos; e a borracha natural é um bem normal.This work aimed to specify and estimate the Brazilian import demand for natural rubber from 1964 to 2005. The variables applied to explain import demand were: natural rubber import price, GNP per capita, exchange nominal rate (R$/US$, "overnight" interest rate, natural rubber domestic production and trend. The estimates showed that the variables significantly affected the Brazilian import demand for natural rubber. The results indicated that the Brazilian import demand for natural rubber is inelastic in relation to import price and income; little sensitive to variations in import price, exchange nominal rate (R$/US$, income and "overnight" interest rate but it is sensitive to domestic rubber production variations , in the short and long runs; and that natural rubber is a regular commodity.

  14. Effect of irradiation on poly(vinyl chloride)/epoxidized natural rubber blend in the presence of additives: FTIR analysis

    International Nuclear Information System (INIS)

    Chantara Thevy Ratnam; Khairul Zaman Dahlan; Baharin, A.; Nasir, M.

    2001-01-01

    The effect of irradiation on the structure of 50/50 poly(vinyl chloride)/epoxidized natural rubber blend (PVC/ENR) was studied using the Fourier Transform Spectroscopy (FTIR). The 50/50 PVC/ENR blend was irradiated by using 3.0 MeV electron beam machine at 0 and 200 kGy irradiation doses. The influence of several additives such as TMPTA, Irganox 1010, and tribasic lead sulfate on the irradiation induced changes of the blend was investigated. It was found that upon irradiation, ring opening of the epoxide groups, oxidation as well crosslinking at residual double bonds occurred, leading to decreases in the intensities of the epoxide and cis double bond bands and an increases in ether and furan bands. The addition of Irganox 1010 and tribasic lead sulfate were found to inhibit the irradiation-induced reaction in the blend to a considerable extent. The importance of TMPTA in preventing the intramolecular ring opening side chain reaction was also discussed. However, studies did not reveal the exact nature of the irradiation-induced reactions involved in the blend. (Author)

  15. Natural Corrosion Inhibitors for Steel Reinforcement in Concrete — a Review

    Science.gov (United States)

    Raja, Pandian Bothi; Ghoreishiamiri, Seyedmojtaba; Ismail, Mohammad

    2015-04-01

    Reinforced concrete is one of the widely used construction materials for bridges, buildings, platforms and tunnels. Though reinforced concrete is capable of withstanding a large range of severe environments including marine, industrial and alpine conditions, there are still a large number of failures in concrete structures for many reasons. Either carbonation or chloride attack is the main culprit which is due to depassivation of reinforced steel and subsequently leads to rapid steel corrosion. Among many corrosion prevention measures, application of corrosion inhibitors play a vital role in metal protection. Numerous range of corrosion inhibitors were reported for concrete protection that were also used commercially in industries. This review summarizes the application of natural products as corrosion inhibitors for concrete protection and also scrutinizes various factors influencing its applicability.

  16. Effect of expanded organoclay by stearic acid to curing, mechanical and swelling properties of natural rubber nanocomposites

    Science.gov (United States)

    Ramadhan, A.; Fathurrohman, M. Irfan; Falaah, A. F.; Setyawan, N.; Soegijono, B.

    2017-07-01

    The interlayer basal spacing of organoclay (OC) could be increased with stearic acid (SA) added, thus OC changed into expanded organoclay by SA (OCSA). The effect of various loadings of OCSA on the curing, mechanical and swelling properties of natural rubber (NR) nanocomposites were studied. The natural rubber/expanded organoclay (NR/OCSA) nanocomposites were prepared by melt intercalation using a laboratory open mill. The curing characteristics of NR compounds were determined using a Moving Die Rheometer (MDR). The X-ray Diffraction (XRD), Attenuated Total Reflectance Infrared (ATR-IR) Spectroscopy and Field Emission Scanning Electron Microscopy (FESEM) were used to study the dispersion of OCSA in the NR matrix. The mechanical properties of NR/OCSA nanocomposites such as tensile strength, elongation at break and hardness were determined using ISO standard and swelling of NR/OCSA nanocomposites in toluene were determined using ISO 1817. The results showed that the SA intercalated into the gallery of OC and reacted with the hydroxyl groups in OC. It was indicated with the shifting of the negative peak 1,700 to 1,723 cm-1 in the ATR-IR spectrum and increase the d-spacing of OC. The adding of various loadings of OCSA into NR could increase the torque and accelerate the curing of nanocomposites and it also could increase the mechanical and swelling properties of nanocomposites. The change in modulus at 100% elongation significantly increased with increasing the OCSA load until maximum loading at 10 phr. This trend was same with the hardness and modulus at 300% elongation. Meanwhile, the improvement of tensile strength and elongation at break was higher at 4 phr OCSA compared with the other loading. The increase of mechanical and swelling properties of NR/OCSA nanocomposites was due to intercalation/exfoliation of OCSA in NR matrix. It was revealed by appearing of the out-of-plane Si-O-(Al) stretch with peak value 1080 cm-1 in the ATR-IR spectrum and the peaks of OCSA

  17. Experimental evaluation and simulation of volumetric shrinkage and warpage on polymeric composite reinforced with short natural fibers

    Science.gov (United States)

    Santos, Jonnathan D.; Fajardo, Jorge I.; Cuji, Alvaro R.; García, Jaime A.; Garzón, Luis E.; López, Luis M.

    2015-09-01

    A polymeric natural fiber-reinforced composite is developed by extrusion and injection molding process. The shrinkage and warpage of high-density polyethylene reinforced with short natural fibers of Guadua angustifolia Kunth are analyzed by experimental measurements and computer simulations. Autodesk Moldflow® and Solid Works® are employed to simulate both volumetric shrinkage and warpage of injected parts at different configurations: 0 wt.%, 20 wt.%, 30 wt.% and 40 wt.% reinforcing on shrinkage and warpage behavior of polymer composite. Become evident the restrictive effect of reinforcing on the volumetric shrinkage and warpage of injected parts. The results indicate that volumetric shrinkage of natural composite is reduced up to 58% with fiber increasing, whereas the warpage shows a reduction form 79% to 86% with major fiber content. These results suggest that it is a highly beneficial use of natural fibers to improve the assembly properties of polymeric natural fiber-reinforced composites.

  18. Investigation of Thermal Behavior for Natural Fibres Reinforced Epoxy using Thermogravimetric and Differential Scanning Calorimetric Analysis

    Directory of Open Access Journals (Sweden)

    Fauzi F.A.

    2016-01-01

    Full Text Available This paper presented the research works on the investigation of the thermal behavior of the natural fibres; i.e. pineapple leaf fibre, kenaf fibre and mengkuang fibres reinforced epoxy. The thermogravimetric analysis and differential scanning calorimetric analysis were used to measure the thermal behavior of the treated and untreated pineapple, kenaf and mengkuang fibres reinforced epoxy. The samples for both analysis were subjected to maximum temperature 600°C at the heating rate of 10°C/min. The results showed that the treated fibres show higher maximum peak temperature as compared to the untreated fibres. Additionally, the glass transition temperature showed a lower value for all treated fibre. It can be concluded that investigation of thermal properties of these natural fibres could improve the utilization of natural fibre composites in various applications i.e. sports applications.

  19. Regulamentação pública e conduta das firmas no sistema agroindustrial da borracha natural entre 1997 e 2000 Regulation and behavior of firms in Brazil's natural rubber agro-industrial system between 1997-2000

    Directory of Open Access Journals (Sweden)

    Augusto Hauber Gamero

    2002-01-01

    Full Text Available A necessidade de regulamentação no sistema agroindustrial (SAG da borracha natural no Brasil é evidente. Desde a metade do século, quando o país passou a importar esse produto, vários esforços governamentais vêm sendo definidos, objetivando o desenvolvimento sustentável do setor da produção agrícola nacional de borracha. No ano de 1997, criou-se uma política de subvenção direta à produção. Dada a estrutura desse SAG, associada à conjuntura do mercado internacional e a uma regulamentação falha do governo federal, começaram a surgir indícios de abuso de poder de mercado pela indústria pneumática instalada no país, principal consumidora do produto. Utilizando o arcabouço teórico da organização industrial, neste artigo se procurou levantar evidências nesse sentido.The need for regulation of Brazil’s natural rubber agro-industrial system (SAG is evident. Since the middle of the 20th century, when the country began importing rubber, many governmental efforts have been made to promote the sustainable development of Brazil’s natural rubber productive sector. In 1997, the Brazilian government created a direct subvention policy to assist rubber producers. Given the structure of Brazil’s SAG, the international rubber market, and imperfect regulation by the Federal Government, it would not be unexpected to find signs that Brazil’s largest natural rubber consumer, the domestic tire industry, has begun to abusively exercise its market power. Using the theoretical structure of Industrial Organization, this paper tries to show evidences of this abuse.

  20. Natural tooth pontic with splinting of periodontally weakened teeth using fiber-reinforced composite resin

    Directory of Open Access Journals (Sweden)

    Gauri Srinidhi

    2014-01-01

    Full Text Available Replacement of missing anterior teeth due to periodontal reasons is challenging due to the poor support of abutment teeth. This prevents the use of fixed partial dentures (FPDs. Fiber-reinforced splinting provides a viable alternative to the dentist while choosing a treatment plan in replacing missing anterior teeth in periodontally compromised patients as opposed to conventional modalities like FPDs or removable partial dentures. Replacing missing teeth using either patient′s own tooth or a denture tooth as pontic can be done by splinting adjacent teeth with fiber reinforced composite. The splinting has an additional advantage of stabilizing adjacent mobile teeth. This case report details the case selection, procedure with follow-up of a case where the natural extracted tooth of the patient was used as pontic to replace a missing anterior tooth. The splinting was done with fiber reinforced composite resin. Fiber-reinforced composite resin splinting of patient′s extracted natural tooth is economical, fast, and easy to use chairside technique with the added benefit of periodontal stabilization.

  1. The Effect of Pre-Tension on Deformation Behaviour of Natural Fabric Reinforced Composite

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    Paulė BEKAMPIENĖ

    2011-03-01

    Full Text Available In the fiber-reinforced composites industry together with the promotion of environmental friendly production, synthetic materials are attempted to be replaced by renewable, biodegradable and recyclable materials. The most important challenge is to improve strength and durability of these materials. Matrix that supports the fiber-reinforcement in composite generally is brittle and deformation causes fragmentation of the matrix. Pre-tension of reinforcement is a well-known method to increase tensile strength of woven material. The current study develops the idea to use pre-tension of woven fabric in order to improve quality and strength properties of the obtained composite. Natural (cotton fiber and synthetic (glass fiber woven fabrics were investigated. The pressure forming operation was carried out in order to study clamping imposed strain variation across the surface of woven fabric. The uniaxial tension test of single-layer composite specimens with and without pre-tension was performed to study the effect of pre-tension on strength properties of composite. The results have shown that pre-tension imposed by clamping is an effective method to improve the quality of shaped composite parts (more smoothed contour is obtained and to increase the strength properties of composite reinforced by woven natural fabric. After pre-tension the tensile strength at break increased in 12 % in warp direction, in 58 % in weft direction and in 39 % in bias direction.http://dx.doi.org/10.5755/j01.ms.17.1.250

  2. Rubber Reclamation

    Science.gov (United States)

    Williams, Kathryn R.

    2007-01-01

    The safety and health hazards related to recycling of used rubber, due to the scarcity and high price of virgin rubber are reported. Various threats like stagnant water pools trapped in tires leading to diseases and ignited tires, which become very difficult to extinguish and generating smoke that is extremely detrimental to the environment, have…

  3. Risk-targeted safety distance of reinforced concrete buildings from natural-gas transmission pipelines

    International Nuclear Information System (INIS)

    Russo, Paola; Parisi, Fulvio

    2016-01-01

    Natural-gas pipeline accidents mostly result in major damage even to buildings located far away. Therefore, proper safety distances should be observed in land use planning to ensure target safety levels for both existing and new buildings. In this paper, a quantitative risk assessment procedure is presented for the estimation of the annual probability of direct structural damage to reinforced concrete buildings associated with high-pressure natural-gas pipeline explosions. The procedure is based on Monte Carlo simulation and takes into account physical features of blast generation and propagation, as well as damage to reinforced concrete columns. The natural-gas jet release process and the flammable cloud size are estimated through SLAB one-dimensional integral model incorporating a release rate model. The explosion effects are evaluated by a Multi-Energy Method. Damage to reinforced concrete columns is predicted by means of pressure–impulse diagrams. The conditional probability of damage was estimated at multiple pressure–impulse levels, allowing blast fragility surfaces to be derived at different performance limit states. Finally, blast risk was evaluated and allowed the estimation of minimum pipeline-to-building safety distances for risk-informed urban planning. The probabilistic procedure presented herein may be used for performance-based design/assessment of buildings and to define the path of new natural-gas pipeline networks. - Highlights: • The safety of buildings against blast loads due to pipeline accidents is assessed. • A probabilistic risk assessment procedure is presented for natural-gas pipelines. • The annual risk of collapse of reinforced concrete building columns is evaluated. • Monte Carlo simulation was carried out considering both pipeline and column features. • A risk-targeted safety distance is proposed for blast strength class 9.

  4. New Elastomeric Materials Based on Natural Rubber Obtained by Electron Beam Irradiation for Food and Pharmaceutical Use

    Directory of Open Access Journals (Sweden)

    Gabriela Craciun

    2016-12-01

    Full Text Available The efficiency of polyfunctional monomers as cross-linking co-agents on the chemical properties of natural rubber vulcanized by electron beam irradiation was studied. The following polyfunctional monomers were used: trimethylolpropane-trimethacrylate, zinc-diacrylate, ethylene glycol dimethacrylate, triallylcyanurate and triallylisocyanurate. The electron beam treatment was done using irradiation doses in the range of 75 kGy–300 kGy. The gel fraction, crosslink density and effects of different aqueous solutions, by absorption tests, have been investigated as a function of polyfunctional monomers type and absorbed dose. The samples gel fraction and crosslink density were determined on the basis of equilibrium solvent-swelling measurements by applying the modified Flory–Rehner equation for tetra functional networks. The absorption tests were done in accordance with the SR ISI 1817:2015 using distilled water, acetic acid (10%, sodium hydroxide (1%, ethylic alcohol (96%, physiological serum (sodium chloride 0.9% and glucose (glucose monohydrate 10%. The samples structure and morphology were investigated by Fourier Transform Infrared Spectroscopy and Scanning Electron Microscopy techniques.

  5. Deproteinised natural rubber latex grafted poly(dimethylaminoethyl methacrylate) - poly(vinyl alcohol) blend membranes: Synthesis, properties and application.

    Science.gov (United States)

    Jayadevan, Janisha; Alex, Rosamma; Gopalakrishnapanicker, Unnikrishnan

    2018-02-01

    Natural rubber latex was initially deproteinised (DNRL) and then subjected to physicochemical modifications to make high functional membranes for drug delivery applications. Initially, DNRL was prepared by incubating with urea, sodiumdodecylsulphate and acetone followed by centrifugation. The deproteinisation was confirmed by CHN analysis. The DNRL was then chemically modified by grafting (dimethylaminoethyl methacrylate) onto NR particles by using a redox initiator system viz; cumene hydroperoxide/tetraethylenepentamine, followed by dialysis for purification. The grafting was confirmed by dynamic light scattering, Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. The grafted system was blended with a hydrophilic adhesive polymer PVA and casted into membranes. The membranes after blending showed enhanced mechanical properties with a threshold concentration of PVA. The moisture uptake, swelling and water contact angle experiments indicated an increased hydrophilicity with an increased PVA content in the blend membranes. The grafted DNRL possessed significant antibacterial property which has been found to be retained in the blended form. A notable decrease in cytotoxicity was observed for the modified DNRL membranes than the bare DNRL membranes. The in-vitro drug release studies using rhodamine B as a model drug, confirmed the utility of the prepared membranes to function as a drug delivery matrix. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Polymer blends made of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) and epoxidized natural rubber: Thermal and mechanical response

    Science.gov (United States)

    Salim, Yoga Sugama; Han, Chan Chin; Kammer, Hans-Werner; Kumar, Sudesh; Neon, Gan Seng

    2015-08-01

    The ever-increasing demand of biodegradable over conventional polymers places microbial polyhydroxyalkanoates (PHA) as an ideal choice of research material for specific applications. In this study, polymer blends made of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) [P(3HB-co-3HHx) and epoxidized natural rubber (ENR) were prepared using solution casting technique. The influence of ENR on thermal, morphological and mechanical properties of P(3HB-co-3HHx) was investigated. There are two glass transition (Tg) temperatures observed using differential scanning calorimeter. This indicates that P(3HB-co-3HHx) and ENR are immiscible at macroscopic level. Although the Tg of P(3HB-co-3HHx) is seen to shift toward ENR in the least manner, infrared analysis suggests that the crystal structure of P(3HB-co-3HHx) retains its conformational structure. In terms of morphology, ENR exists as droplets in P(3HB-co-3HHx)-rich phase, e.g. at ENR weight fraction (wENR) of 0.3. In dynamic mechanical analysis, all blend compositions exhibit solid-like behavior, with storage moduli larger than loss moduli, across the frequency sweep at room temperature.

  7. Swelling behaviour in n-pentane and mechanical properties of epoxidized natural rubber with different epoxide content

    Science.gov (United States)

    Kinasih, N. A.; Fathurrohman, M. I.; Winarto, D. A.

    2017-07-01

    Epoxidized natural rubber (ENR) with different level of epoxidation (i.e. 10, 20, 30, 40 and 50 mol% indicated as ENR ENR10, ENR20, ENR30, ENR40 and ENR50, respectively) were prepared. They were then vulcanized by using efficient system vulcanization. The effect of epoxide content on curing characteristic, swelling and mechanical properties in N-pentane was investigated. The Attenuated Resonance Fourier Transform Infrared (ATR-FTIR) and H-Nuclear Magnetic Resonance (H-NMR) were used to determine the epoxidation level. Glass transition (Tg) of ENR samples was determined by using Direct Scanning Calorimetry (DSC). The result revealed that the resistance of ENR in N-pentane increased with increasing epoxidation level, which indicated by decreasing equilibrium mol uptake and diffusion coefficient. The compression set of ENR and aging resistance increased with increasing epoxide content, except ENR50 was due to ENR 50 have two Tg value. However, the value of hardness and tensile strength were not effected by epoxidation level.

  8. Efficiency of 1,9- Nonane-diol-diacrylate as a radiation vulcanization accelerator for natural rubber latex

    International Nuclear Information System (INIS)

    Haque, M.E.

    2003-09-01

    The efficiency of 1,9- Nonane-diol-diacrylate (NDDA) as a radiation vulcanization accelerator (RVA) for natural rubber latex (NRL) was investigated. Both gamma rays and electron beam (EB) were used for vulcanizing NRL with NDDA. The radiation dose of gamma rays, concentration of NDDA required to vulcanize the latex were optimized. 20 kGy radiation dose of gamma rays and 5 phr concentration of NDDA were found optimum to get maximum tensile and related properties. NRL was vulcanized under EB to find out the optimum condition of irradiation with this RVA. The defoamer concentrations, length of irradiation time under EB, concentration of RVA were optimizer by changing various parameters of the EB machine with a constant set of the others. 0.2 phr defoamer concentration, 30 minutes irradiation time and 5 phr concentration of NDDA were found optimum for irradiation of NRL under the EB machine. Effect of low current and optimum volume of latex charged in the reaction vessel suitable for vulcanization at a time were found out. (author)

  9. Assessment of the genetic diversity of natural rubber tree clones of the SINCHI Institutes clone collection, using of morphological descriptors

    International Nuclear Information System (INIS)

    Quesada Mendez, Isaac; Quintero Barrera, Lorena; Aristizabal, Fabio A; Rodriguez Acuna, Olga

    2011-01-01

    Genetic diversity of natural rubber clones of the in SINCHI Institute’s clone collection was assessed. Clones of Hevea brasiliensis (Willd. ex Adr. De Juss.) Muell.Arg., Hevea spp. (H. brasiliensis x H. benthamiana), and three more species of Hevea genus are a part of the collection. Seventy-two materials were characterized with twenty-eight morphological descriptors. They were later used to generate a similarity matrix through the analysis of multi-categorical variables, and to obtain clusters based on the matrix. A low variability between clones of H. brasiliensis and H. spp. was observed, presumably because of the direct descendants of most of the materials from crosses of parental PB 80, PB 5/51, PB 49 and Tjir, exception made of clone GU 1410. Clustering between some materials product of exclusive cross of PB series, a group between clones descendants of parental clones PB 86, and clustering between descendants of parental clones PB 5/51, were observed. Clones from other species of Hevea differ from this big group.

  10. Analysis of sulfidic linkages formed in natural rubber latex medical gloves by using X-ray absorption near edge structure

    Science.gov (United States)

    Chankrachang, M.; Limphirat, W.; Yongyingsakthavorn, P.; Nontakaew, U.; Tohsan, A.

    2017-09-01

    A study of sulfidic linkages formed in natural rubber (NR) latex medical gloves by using X-ray Absorption Near Edge Structure (XANES) is presented in this paper. The NR latex compound was prepared by using prevulcanization method, that is, it was prevulcanized at room temperature for 24 hrs before utilization. After the 24 hrs of prevulcanization, the latex film samples were obtained by dipping process. The dipped films were subjected to vulcanize at 110°C for 5 to 25 min. It was observed that after the compound was prevulcanized for 24 hrs, polysulfidic linkages were mainly formed in the sample. It was however found that after curing at 110°C for 5-25 min, the polysulfidic linkages are tended to change into disulfide linkages. Especially, in the case of 25 minutes cured sample, disulfide linkages are found to be the main linkages. In term of tensile strength, it was observed that when cure time increased from 5 - 10 min, tensile strengths were also increased. But when the cure time of the film is 25 minutes, tensile strength was slightly dropped. The dropped of tensile strength when cure time is longer than 10 minutes can be ascribed to a degradation of polysulfidic and disulfidic linkages during curing. Therefore, by using XANES analysis, it was found to be very useful to understand the cure characteristic, thus it can be very helpful to optimize cure time and tensile properties of the product.

  11. The Influence of Irganox 245 on Crystallinity and Mechanics Stability of Polypropylene-Natural Rubber Poly blends

    International Nuclear Information System (INIS)

    Mashuri; Kristiawan Setia; Darminto; Aloma KK; Sudirman

    2008-01-01

    The influence of irganox 245 on crystallinity and mechanics stability of polyethylene (PP)- Natural Rubber (NR) poly blends exposure by sunlight for 12 weeks has been studied. For optimalization of antioxidant function to reduce oxidation in PP-NR (4:1) poly blends irganox 245 with variation concentration of 4 %, 6 %, 8 % and 10 % vol were added. Poly blends was made by blending method at 170 o C for 10 minutes with form an 30 rpm. The result showed that irganox 245 could not increasing adhesion at the interface between PP-NR, so PP-NR still immiscible blends. The optimal concentrations of irganox 245 as antioxidant on PP-NR poly blends is 8 % vol. PP-NR-irganox 245 8 % vol have decreasing tensile strength up to 6 % and increasing elongation at break up to 50 % in exposure by sunlight at long time 8 weeks but for 12 weeks tensile strength and elongation at break very weaks. Crystallinity and mechanics stability of PP-NR-irganox 245 8 % vol better than PP-NR poly blends, it is showed by slowly defects and decreasing crystallinity up to 9 % for exposure 12 weeks. (author)

  12. Preparation and characterization of nanocomposites of natural rubber with polystyrene and styrene-methacrylic acid copolymer nanoparticles

    Directory of Open Access Journals (Sweden)

    T. Nuruk

    2012-06-01

    Full Text Available Composites of natural rubber (NR/vinyl polymer nanoparticles as polystyrene (PS and poly(styrenemethacrylic acid (P(S-MAA were prepared by heterocoagulation technique. The polymer nanoparticles were prepared by emulsifier-free emulsion polymerizations at 70°C using potassium persulfate as initiator. Under acidic condition where positive charge was present on the NR latex (NRL surface, the nanoparticles having negative charge mainly from sulfate group of initiator were able to adsorb on the NRL surface, the electrostatic interaction being the driving force. The scanning electron micrographs showed that the polymer nanoparticles are homogenously distributed throughout NR matrix as nanoclusters with an average size of about 500 and 200 nm for PS and P(S-MAA, respectively. The mechanical properties of NR/PS and NR/P(S-MAA composite films were compared with the NR host. The nanocomposites, particularly when the polymer nanoparticles are uniformly dispersed, possess significantly enhanced mechanical properties strongly depending on the morphology of the nanocomposites.

  13. In vitro cytotoxicity and genotoxicity of composite mixtures of natural rubber and leather residues used for textile applications.

    Science.gov (United States)

    Cavalcante, Dalita Gsm; Gomes, Andressa S; Dos Reis, Elton Ap; Danna, Caroline S; Kerche-Silva, Leandra E; Yoshihara, Eidi; Job, Aldo E

    2017-06-01

    A novel composite material has been developed from natural rubber and leather waste, and a corresponding patent has been filed. This new material may be incorporated into textile and footwear products. However, as leather waste contains chromium, the biocompatibility of this new material and its safety for use in humans must be investigated. The aim of the present study was to investigate the presence of chromium in this new material, determine the amount of each form of chromium present (trivalent or hexavalent), and evaluate the potential cytotoxic and genotoxic effects of the novel composite in two cell lines. The cellular viability was quantified using the MTT3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction method and neutral red uptake assay, and genotoxic damage was analyzed using the comet assay. Our findings indicated that the extracts obtained from the composite were severely cytotoxic to both cell lines tested, and additionally highly genotoxic to MRC-5 cells. These biological responses do not appear to be attributable to the presence of chromium, as the trivalent form was predominantly found to be present in the extracts, indicating that hexavalent chromium is not formed during the production of the novel composite. The incorporation of this new material in applications that do not involve direct contact with the human skin is thus indicated, and it is suggested that the chain of production of this material be studied in order to improve its biocompatibility so that it may safely be used in the textile and footwear industries.

  14. Hevea brasiliensis natural rubber latex film vulcanization by gamma radiation containing n-butyl acrylate: properties and morphology; Filme de latex de borracha natural de Hevea brasiliensis vulcanizado por radiacao gama contendo acrilato de n-butila: propriedades e morfologia

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Ana Paula Pinho; Barros, Glaucione Gomes de [Brasilia Univ., DF (Brazil). Dept. de Quimica; Guedes, Selma M.L. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    1997-07-01

    Radiation vulcanization of natural rubber latex (RVNRL) in the presence of n-butyl acrylate (n-Ba) as sensitizer was carried out. The RVNRL films were investigated with respect to their thermal properties and morphology. The films presented two T{sub g} values obtained by DSC which were identified as due to linear and crosslinked domains. The thermal stability of the material was similar to that of linear material rubber. The morphology showed smooth regular surface characteristic of homogeneous phase domains. (author)

  15. Technological properties of latex and natural rubber of Hevea brasiliensis clones Propriedades tecnológicas do látex e da borracha natural de clones de Hevea brasiliensis

    Directory of Open Access Journals (Sweden)

    Rogério Manoel Biagi Moreno

    2005-04-01

    Full Text Available Rubber industry has increased the requirements for quality and uniformity of natural rubber produced in Brazil. Technological properties of latex and natural rubber of clones GT 1, PB 235, IAN 873 and RRIM 600 [Hevea brasiliensis (Willd. Former Adr. de Juss. Muell.- Arg] were evaluated by standard methods of the dry rubber content (DRC%, percentage of nitrogen (N% and percentage of ashes (ASH% in two consecutive years; data were correlated with temperature and precipitation. Properties of latex and natural rubber varied (P A indústria da borracha está cada vez mais exigente em relação à qualidade e a uniformidade da borracha natural produzida no Brasil. Neste trabalho as propriedades tecnológicas do látex e da borracha natural dos clones de seringueira GT 1, PB 235, IAN 873 e RRIM 600 [Hevea brasiliensis (Willd. ex Adr. de Juss. Muell.-.Arg] foram avaliadas pelos ensaios padrões do conteúdo de borracha seca (DRC%, porcentagem de nitrogênio (N% e porcentagem de cinzas (CNZ% por dois anos consecutivos; os dados obtidos foram correlacionados com dados de temperatura e precipitação. As propriedades do látex e da borracha natural variaram (P < 0.01 em função do tipo de clone e entre coletas. O DRC% diminuiu no início da estação seca (maio a junho, enquanto N% e CNZ% aumentaram. O período de abril a junho revelou ser crítico, pois os valores da N% oscilaram acima 0,60%, fora dos padrões estabelecidos pela norma técnica brasileira ABNT/NBR. O clone RRIM 600 foi menos suscetível às variações climáticas.

  16. Large natural draught cooling towers of reinforced concrete - present state and future developments

    International Nuclear Information System (INIS)

    Kraetzig, W.B.

    1975-01-01

    The paper attempts to give a survey of the present state of safety theory as well as of construction and erection of reinforced-concrete natural draught cooling towers. Today these constructions have reached heights of over 150 m and may be built still higher. From the point of view of safety and relibility this is undoubtedly possible. From an economical point of view, new constructional elements will probably have to be introduced into the design. (orig./AK) [de

  17. Reactive processing of textile-natural fiber reinforced anionic polyamide-6 composites

    International Nuclear Information System (INIS)

    Kan, Ze; Chen, Peng; Liu, Zhengying; Feng, Jianmin; Yang, Mingbo

    2015-01-01

    Nowadays natural fiber, used in reinforced composites, is widely concerned. However, no natural fiber reinforced reactive thermoplastic polymer grades had been prepared so far. Through our studies, it was demonstrated that there was a severe retardation and discoloration occurred in the reactive processing between anionic polyamide-6 (APA-6) and natural fiber, which result in incomplete polymerization when put together. In order to solve the problem, two methods were adopted in this paper, which are fiber pretreatment and usage of a new-style initiator called caprolactam magnesium bromide. The former is to remove sizing agent and impurities on the surface of fiber, and the latter is to weaken the side reactions between APA-6 and natural fiber by the nature of its lower reactivity and weaker alkaline. In cooperation with both methods, the severe retardation and discoloration had been improved significantly, so that the polymerization of APA-6 in natural fiber was occurred smoothly. Following textile-natural fiber reinforced APA-6 composites with an average thickness of 2.5 mm and a fiber volume content of 50% was prepared by vacuum assisted resin transfer molding (VARTM). The soxhlet extraction, dilute solution viscometry and differential scanning calorimeter (DSC) measurements respectively suggested the degree of conversion, viscosity-average molar mass and crystallization of composites was up to 94%, 11.3×104 and 50%. Remarkable improvement of mechanical properties were achieved through dynamic mechanical analysis (DMA), tensile and three-point bending test. Favorable interfacial adhesion and wettability were revealed by scanning electron microscopy (SEM) observation. Therefore, all of the above good performance make this new-style and environmentally friendly composites have broad application prospects

  18. Reactive processing of textile-natural fiber reinforced anionic polyamide-6 composites

    Science.gov (United States)

    Kan, Ze; Chen, Peng; Liu, Zhengying; Feng, Jianmin; Yang, Mingbo

    2015-05-01

    Nowadays natural fiber, used in reinforced composites, is widely concerned. However, no natural fiber reinforced reactive thermoplastic polymer grades had been prepared so far. Through our studies, it was demonstrated that there was a severe retardation and discoloration occurred in the reactive processing between anionic polyamide-6 (APA-6) and natural fiber, which result in incomplete polymerization when put together. In order to solve the problem, two methods were adopted in this paper, which are fiber pretreatment and usage of a new-style initiator called caprolactam magnesium bromide. The former is to remove sizing agent and impurities on the surface of fiber, and the latter is to weaken the side reactions between APA-6 and natural fiber by the nature of its lower reactivity and weaker alkaline. In cooperation with both methods, the severe retardation and discoloration had been improved significantly, so that the polymerization of APA-6 in natural fiber was occurred smoothly. Following textile-natural fiber reinforced APA-6 composites with an average thickness of 2.5 mm and a fiber volume content of 50% was prepared by vacuum assisted resin transfer molding (VARTM). The soxhlet extraction, dilute solution viscometry and differential scanning calorimeter (DSC) measurements respectively suggested the degree of conversion, viscosity-average molar mass and crystallization of composites was up to 94%, 11.3×104 and 50%. Remarkable improvement of mechanical properties were achieved through dynamic mechanical analysis (DMA), tensile and three-point bending test. Favorable interfacial adhesion and wettability were revealed by scanning electron microscopy (SEM) observation. Therefore, all of the above good performance make this new-style and environmentally friendly composites have broad application prospects.

  19. Caracterização das propriedades reológicas e dinâmicas de composições de borracha natural com resíduo de EVA Characterization of rheological and dynamic properties of natural rubber compositions with waste EVA

    Directory of Open Access Journals (Sweden)

    Marcia G. Oliveira

    2004-12-01

    Full Text Available O resíduo de EVA oriundo das indústrias calçadistas é um material reticulado, que apresenta grande potencial de uso como carga em composições elastoméricas. Neste trabalho, foram avaliadas as propriedades reológicas e dinâmicas das composições de borracha natural (NR com resíduo de EVA (EVAR, determinadas com o auxílio do analisador de processamento de borracha (RPA. As composições não-vulcanizadas tiveram a sua viscosidade aumentada pela adição de teores crescentes de EVAR. Após a vulcanização essas composições apresentaram menor elasticidade que a NR pura, como evidenciado nas maiores taxas de relaxamento do módulo e nos maiores valores de tan delta. Este comportamento foi confirmado pelos resultados de tensão e alongamento na ruptura.The EVA waste (EVAR is a crosslinked material, which can be used as filler in rubber compositions. In this work, rheological and dynamic properties of natural rubber (NR compositions with EVAR were investigated before and after vulcanization with the help of a rubber processing analyzer (RPA. The filler content varied from 0 to 60 phr. The results showed that rheological properties of nonvulcanized compositions were clearly modified by the addition of EVAR, which contributed to an increase in viscosity. The modulus relaxation and the dynamic properties such as tan delta of vulcanized compositions were also affected, by the reduction of the elasticity of the compositions. The mechanical properties corroborated the behavior revealed by RPA analysis and indicated that EVAR acted as a non-reinforcing filler.

  20. Manufacturing and Structural Feasibility of Natural Fiber Reinforced Polymeric Structural Insulated Panels for Panelized Construction

    Directory of Open Access Journals (Sweden)

    Nasim Uddin

    2011-01-01

    Full Text Available Natural fibers are emerging in the fields of automobile and aerospace industries to replace the parts such as body panels, seats, and other parts subjected to higher bending strength. In the construction industries, they have the potential to replace the wood and oriented strand boards (OSB laminates in the structural insulated panels (SIPs. They possess numerous advantages over traditional OSB SIPs such as being environmental friendly, recyclable, energy efficient, inherently flood resistant, and having higher strength and wind resistance. This paper mainly focuses on the manufacturing feasibility and structural characterization of natural fiber reinforced structural insulated panels (NSIPs using natural fiber reinforced polymeric (NFRP laminates as skin. To account for the use of natural fibers, the pretreatments are required on natural fibers prior to use in NFRP laminates, and, to address this issue properly, the natural fibers were given bleaching pretreatments. To this end, flexure test and low-velocity impact (LVI tests were carried out on NSIPs in order to evaluate the response of NSIPs under sudden impact loading and uniform bending conditions typical of residential construction. The paper also includes a comparison of mechanical properties of NSIPs with OSB SIPs and G/PP SIPs. The results showed significant increase in the mechanical properties of resulting NSIP panels mainly a 53% increase in load-carrying capacity compared to OSB SIPs. The bending modulus of NSIPs is 190% higher than OSB SIPs and 70% weight reduction compared to OSB SIPs.

  1. A Review on Natural Fiber Reinforced Polymer Composite and Its Applications

    Directory of Open Access Journals (Sweden)

    Layth Mohammed

    2015-01-01

    Full Text Available Natural fibers are getting attention from researchers and academician to utilize in polymer composites due to their ecofriendly nature and sustainability. The aim of this review article is to provide a comprehensive review of the foremost appropriate as well as widely used natural fiber reinforced polymer composites (NFPCs and their applications. In addition, it presents summary of various surface treatments applied to natural fibers and their effect on NFPCs properties. The properties of NFPCs vary with fiber type and fiber source as well as fiber structure. The effects of various chemical treatments on the mechanical and thermal properties of natural fibers reinforcements thermosetting and thermoplastics composites were studied. A number of drawbacks of NFPCs like higher water absorption, inferior fire resistance, and lower mechanical properties limited its applications. Impacts of chemical treatment on the water absorption, tribology, viscoelastic behavior, relaxation behavior, energy absorption flames retardancy, and biodegradability properties of NFPCs were also highlighted. The applications of NFPCs in automobile and construction industry and other applications are demonstrated. It concluded that chemical treatment of the natural fiber improved adhesion between the fiber surface and the polymer matrix which ultimately enhanced physicomechanical and thermochemical properties of the NFPCs.

  2. Effect of liquid epoxidized natural rubber (LENR) on mechanical properties and morphology of natural rubber/high density polyethylene/mengkuang fiber (NR/HDPE/MK) bio-composite

    Science.gov (United States)

    Piah, Mohd Razi Mat; Baharum, Azizah

    2016-11-01

    The use of mengkuang fiber (MK) fibers in NR/HDPE (40/60) blend was studied via surface modification of fiber. The MK fiber was pre-washed with 5%wt/v sodium hydroxide solution prior to treatment with liquid epoxidized natural rubber (LENR). The concentration of LENR were varied from 5%-20%wt in toluene. The effects of LENR concentrations were studied in terms of mechanical properties and morphology formed. Melt-blending was performed using an internal mixer (Haake Rheomix 600). The processing parameters identified were 135°C temperature, 45 rpm rotor speed, 12 minutes processing time and at 20%wt MK fiber loading. The optimum LENR treatment concentration was obtained at 5%wt with tensile strength, tensile modulus, and impact strength of 10.3 MPa, 414.2 MPa and 14.4 kJ/m2 respectively. The tensile modulus of LENR-treated MK fiber filled NR/HDPE bio-composite has shown enhancement up to 16.7% higher than untreated MK fiber. The tensile and impact strength were decreased with increasing LENR concentration due to the broken of MK fibers to smaller particles and adhered to each other. FESEM micrographs confirmed the formation of fiber-fiber agglomeration in NR/HDPE blends. The optical microscope analysis shows MK fibers is shorter than original fiber lengths after NaOH-LENR surface modification. The internal bonding forces of MK fiber seems to be weaker than external force exerted on it, therefore, the MK fiber has broken to smaller particles and reduced the mechanical properties of NR/HDPE/MK(20%) bio-composite.

  3. Magnesium affects rubber biosynthesis and particle stability in Ficus elastica, Hevea brasiliensis and Parthenium argentatum

    Science.gov (United States)

    Natural rubber biosynthesis occurs in laticifers of Ficus elastica and Hevea brasiliensis, and in parenchyma cells of Parthenium argentatum. Natural rubber is synthesized by rubber transferase using allylic pyrophosphates as initiators, isopentenyl pyrophosphate as monomeric substrate and magnesium ...

  4. Mechanical properties of hexaferite based magnet composite of SrFe12019 and BaFe12O19 with natural rubber bonding agent

    International Nuclear Information System (INIS)

    Waluyo, T.; Herman, Y.A.; Sudirman; Ridwan

    2000-01-01

    Research on mechanical properties at magnet composite of SrFe 12 0 19 (SrM) and BaFe 12 O 19 (BaM)magnet powder with natural rubber bonding agent have been done. The natural rubber used was rubber made of latex without vulcanization, The SrM powder having average particle size of 1.6 μm and flat shaped. and the BaM powder having particle size of 1.2 μm and nodular shaped. The production of composite carried out in Labo Plastomill at 100 o C and mixer speed of 30 rpm for 7 minutes. The result obtained from Labo Plastomill then made into sheets. Mechanical properties of the composite tested were strain, elongation break and hardness, The results showed that the highest strain of the SrM composite obtained at composition of 70% vol of powder that is 2,22 MPa, and 3,84 MPa for BaM composite at 50% vol. of powder The elongation break of SrM composite decreased by increasing of powder volume fraction, that is 90% at the composition or 70% vol. of powder, and 370% for BaM composite at 50% vol. fraction of powder. The highest hardness for SrM composite obtained at composition of of 70% vol. of powder, that is 95 SHA. and for the BaM composite at 50% vol. of powder. that is 52 SHA

  5. Reaction of oxygen with γ, δ-ethylenic phenylhydrazones. Model reaction of end-group behavior in phenylhydrazine-accelerated oxidation of natural rubber

    International Nuclear Information System (INIS)

    El Hamdaoui, A.; Reyx, D.; Campistron, I.

    1995-01-01

    An accurate definition of terminal groups of chains in the liquid polymers obtained by the phenylhydrazine-accelerated oxidation of natural rubber is needed. The object of the work was to use model molecules to explore the behavior of γ,δ-ethylenic methylketone phenylhydrazone end-groups in oxidation conditions. We have investigated the synthesis and characterization of models of these hypothetical end-groups, methylketones and phenones 1, their phenylhydrazones 2, the α-(phenyldiazenyl)hydroperoxides 3 resulting from reaction of 2 with oxygen, and the α-(phenyldiazenyl)alcohols 4 as characteristic derivatives of 3 or as models of possible reduced structures in oxidized liquid natural rubber. Three original syntheses of γ,δ-ethylenic ketones were carried out. In the case of γ,δ-ethylenic phenylhydrazones, the oxidation led to the expected α-(phenyldiazenyl)hydroperoxides and to epoxide derivatives of α-(phenyldiazenyl)alcohols 5 and ketones 6. An intramolecular mechanism is proposed. The results are used to predict the possibilities of identification of the corresponding end-groups in liquid rubbers produced in this way. (authors). 16 refs., 12 figs., 3 tabs

  6. Development of a Hybrid Piezo Natural Rubber Piezoelectricity and Piezoresistivity Sensor with Magnetic Clusters Made by Electric and Magnetic Field Assistance and Filling with Magnetic Compound Fluid.

    Science.gov (United States)

    Shimada, Kunio; Saga, Norihiko

    2017-02-10

    Piezoelements used in robotics require large elasticity and extensibility to be installed in an artificial robot skin. However, the piezoelements used until recently are vulnerable to large forces because of the thin solid materials employed. To resolve this issue, we utilized a natural rubber and applied our proposed new method of aiding with magnetic and electric fields as well as filling with magnetic compound fluid (MCF) and doping. We have verified the piezoproperties of the resulting MCF rubber. The effect of the created magnetic clusters is featured in a new two types of multilayered structures of the piezoelement. By measuring the piezoelectricity response to pressure, the synergetic effects of the magnetic clusters, the doping and the electric polymerization on the piezoelectric effect were clarified. In addition, by examining the relation between the piezoelectricity and the piezoresistivity created in the MCF piezo element, we propose a hybrid piezoelement.

  7. Development of a Hybrid Piezo Natural Rubber Piezoelectricity and Piezoresistivity Sensor with Magnetic Clusters Made by Electric and Magnetic Field Assistance and Filling with Magnetic Compound Fluid

    Science.gov (United States)

    Shimada, Kunio; Saga, Norihiko

    2017-01-01

    Piezoelements used in robotics require large elasticity and extensibility to be installed in an artificial robot skin. However, the piezoelements used until recently are vulnerable to large forces because of the thin solid materials employed. To resolve this issue, we utilized a natural rubber and applied our proposed new method of aiding with magnetic and electric fields as well as filling with magnetic compound fluid (MCF) and doping. We have verified the piezoproperties of the resulting MCF rubber. The effect of the created magnetic clusters is featured in a new two types of multilayered structures of the piezoelement. By measuring the piezoelectricity response to pressure, the synergetic effects of the magnetic clusters, the doping and the electric polymerization on the piezoelectric effect were clarified. In addition, by examining the relation between the piezoelectricity and the piezoresistivity created in the MCF piezo element, we propose a hybrid piezoelement. PMID:28208625

  8. Development of a Hybrid Piezo Natural Rubber Piezoelectricity and Piezoresistivity Sensor with Magnetic Clusters Made by Electric and Magnetic Field Assistance and Filling with Magnetic Compound Fluid

    Directory of Open Access Journals (Sweden)

    Kunio Shimada

    2017-02-01

    Full Text Available Piezoelements used in robotics require large elasticity and extensibility to be installed in an artificial robot skin. However, the piezoelements used until recently are vulnerable to large forces because of the thin solid materials employed. To resolve this issue, we utilized a natural rubber and applied our proposed new method of aiding with magnetic and electric fields as well as filling with magnetic compound fluid (MCF and doping. We have verified the piezoproperties of the resulting MCF rubber. The effect of the created magnetic clusters is featured in a new two types of multilayered structures of the piezoelement. By measuring the piezoelectricity response to pressure, the synergetic effects of the magnetic clusters, the doping and the electric polymerization on the piezoelectric effect were clarified. In addition, by examining the relation between the piezoelectricity and the piezoresistivity created in the MCF piezo element, we propose a hybrid piezoelement.

  9. Initiation and inhibition of pitting corrosion on reinforcing steel under natural corrosion conditions

    Energy Technology Data Exchange (ETDEWEB)

    Abd El Wanees, S., E-mail: s_wanees@yahoo.com [Chemistry Department, Faculty of Science, University of Tabuk, Tabuk (Saudi Arabia); Chemistry Department, Faculty of Science, Zagazig University, Zagazig 44519 (Egypt); Bahgat Radwan, A. [Center for Advanced Materials, Qatar University, Doha 2713 (Qatar); Alsharif, M.A. [Chemistry Department, Faculty of Science, University of Tabuk, Tabuk (Saudi Arabia); Abd El Haleem, S.M. [Chemistry Department, Faculty of Science, Zagazig University, Zagazig 44519 (Egypt)

    2017-04-01

    Initiation and inhibition of pitting corrosion on reinforcing steel in saturated, naturally aerated Ca(OH){sub 2} solutions, under natural corrosion conditions, are followed through measurements of corrosion current, electrochemical impedance spectroscopy and SEM investigation. Induction period for pit initiation and limiting corrosion current for pit propagation are found to depend on aggressive salt anion and cation-types, as well as, concentration. Ammonium chlorides and sulfates are more corrosive than the corresponding sodium salts. Benzotriazole and two of its derivatives are found to be good inhibitors for pitting corrosion of reinforcing steel. Adsorption of these compounds follows a Langmuir adsorption isotherm. The thermodynamic functions ΔE{sup ∗}, ΔH{sup ∗} and ΔS{sup ∗} for pitting corrosion processes in the absence and presence of inhibitor are calculated and discussed. - Highlights: • Cl{sup −} and SO{sub 4} {sup 2-} induce pitting corrosion on passive reinforcing steel. • Initiation and propagation of pitting depend on cation and anion types. • Inhibition is based on adsorption according to Langmuir isotherm.

  10. Influência da taxa de câmbio e do dólar sobre os preços da borracha natural brasileira Influence of exchange rate and dollar over the Brazilian natural rubber price

    Directory of Open Access Journals (Sweden)

    Naisy Silva Soares

    2013-04-01

    Full Text Available Este estudo analisou a influência da taxa de câmbio adotada pelo Brasil e do dólar sobre os preços da borracha natural em moeda brasileira, de janeiro de 2000 a dezembro de 2009. Para isso, fez-se uso do método "shift-share". Considerando os resultados obtidos, observou-se que as variações ocorridas nos preços da borracha natural em moeda brasileira sofreram maior influência das variações do dólar que das variações da taxa de câmbio, mostrando a importância dos preços da borracha natural na Malásia sobre o comportamento dos preços da borracha natural no Brasil.This study analyzed the influence of exchange rate adopted by Brazil and of the dollar over the prices of the Brazilian Natural Rubber in Brazilian currency, from January 2003 to December 2009. Thus, the shift-share method was used. By considering the results achieved in this study, it was found that changes in prices of natural rubber in Brazilian currency were more influenced by the dollar variations than variations in exchange rate, showing the importance of prices in Malasya over the performance of natural rubber prices in Brazil.

  11. Aspects of Degradability and Aging of Natural Rubber Latex Films Obtained by Induced Ionizing Radiation Processes of Latex Vulcanization

    International Nuclear Information System (INIS)

    Parra, D. F.

    2006-01-01

    This study refers to the degradability of NRLF, natural rubber latex films, obtained by ionizing radiation. Three types of NRLF were prepared: irradiated latex, irradiated latex with about 1% of soy lecithin and sulfur-vulcanized latex, by cold vulcanization process. The films were buried in vases of two different kinds of soil: common soil and common soil with earthworm humus. Fast aging tests in laboratory with exposition to ultraviolet rays were done in irradiated latex films and irradiated latex films with soy lecithin. The results obtained after ten months of tests with buried films agree with the results of the fast aging tests, showing singularities of each type of soil and each kind of latex process. It also shows how weather inclemency can induce the films degradation process. The sulfur-vulcanized films were weakly degraded when buried. The films with lecithin and buried in vase with only common soil showed the biggest mass loss, but the films with lecithin buried in vases with common earthworm humus and soil increased their weigh and dimensions due to fungi formation. The irradiated latex films are more degradable then the sulfur-vulcanized films. The irradiated latex film, unlike the sulfur vulcanized film, showed high fungi colonization when buried. We conclude that the irradiated latex films are more easily biodegradable than the sulfur vulcanized latex films. The biodegradability increases with the addition of small amounts of soy lecithin (∼1%). The mechanical resistance of the buried films decreased related to the non-buried ones, proving that the outdoor aging in soil and the presence of fungi in the films can modify the mechanical properties of the irradiated latex owing to the biodegradation

  12. Advances in rubber/halloysite nanotubes nanocomposites.

    Science.gov (United States)

    Jia, Zhixin; Guo, Baochun; Jia, Demin

    2014-02-01

    The research advances in rubber/halloysite nanotubes (rubber/HNTs) nanocomposites are reviewed. HNTs are environmentally-friendly natural nanomaterials, which could be used to prepare the rubber-based nanocomposites with high performance and low cost. Unmodified HNTs could be adopted to prepare the rubber/HNTs composites with improved mechanical properties, however, the rubber/HNTs nanocomposites with fine morphology and excellent properties were chiefly prepared with various modifiers by in situ mixing method. A series of rubber/HNTs nanocomposites containing several rubbers (SBR, NR, xSBR, NBR, PU) and different modifiers (ENR, RH, Si69, SA, MAA, ILs) have been investigated. The results showed that all the rubber/HNTs nanocomposites achieved strong interfacial interaction via interfacial covalent bonds, hydrogen bonds or multiple interactions, realized significantly improved dispersion of HNTs at nanoscale and exhibited excellent mechanical performances and other properties.

  13. Compósitos de borracha natural ou policloropreno e celulose II: influência do tamanho de partícula Natural rubber or chloroprene rubber and cellulose II composites: influence of particle size

    Directory of Open Access Journals (Sweden)

    Bruno de A. Napolitano

    2004-01-01

    Full Text Available O objetivo deste trabalho foi o desenvolvimento de compósitos claros com propriedades de interesse tecnológico utilizando elastômeros com diferentes polaridades. Para que este objetivo fosse atingido, celulose II em pó foi usada como carga, em borracha natural (NR ou policloropreno (CR. A celulose II foi obtida por coagulação da solução de xantato de celulose em meio ácido, sob agitação constante e à temperatura ambiente, constituindo uma nova forma de obtenção deste tipo de carga. Compósitos com 10 phr de celulose II com NR e CR, respectivamente, foram desenvolvidos tendo como variável o tamanho de partícula da carga. As propriedades mecânicas e os aspectos microscópicos dos diferentes compósitos foram avaliados e comparados com aqueles das formulações sem carga. Os resultados permitiram identificar o compósito como o de melhor resultado, influenciado pela polaridade da matriz elastomérica e pelo tamanho de partícula da carga, conseqüência das condições de moagem usadas.The aim of this work was to develop light composites with properties of technological interest by using elastomers of different polarities. This was achieved by employing cellulose II, in the powder form, as filler in natural rubber (NR and chloroprene (CR. Cellulose II was obtained by coagulation of cellulose xanthate solution, in acid medium, under stirring and at room temperature, which represents, to our knowledge, a new way of obtaining this type of filler. Composites with 10phr of cellulose II and NR or CR were prepared having the particle size as variable. The mechanical properties and the microscopic aspect of the different composites were evaluated and compared with compounds without filler. The results indicated best results for the CR composite, influenced by the polarity of the elastomeric matrix and by the particle size, as a consequence of the milling conditions of the filler used.

  14. Influence of Coating with Some Natural Based Materials on the Erosion Wear Behavior of Glass Fiber Reinforced Epoxy Resin

    OpenAIRE

    Aseel Basim Abdul Hussein; Emad Saadi AL-Hassani; Reem Alaa Mohamed

    2015-01-01

    In the present study, composites were prepared by Hand lay-up molding. The composites constituents were epoxy resin as a matrix, 6% volume fractions of glass fibers (G.F) as reinforcement and 3%, 6% volume fractions of preparation natural material (Rice Husk Ash, Carrot Powder, and Sawdust) as filler. Studied the erosion wear behavior and coating by natural wastes (Rice Husk Ash) with epoxy resin after erosion. The results showed the non – reinforced epoxy have lower resistance erosion than n...

  15. Study on the production of kanvas shoes adhesive from natural rubber latex grafted with methyl methacrylate (NRL-g PMMA) copolymer

    International Nuclear Information System (INIS)

    Utama, Marga; Sudirman; Setyowati, Penny

    2002-01-01

    The optimation condition of radiation copolymerization of MMA into natural rubber latex at the doses of radiation : 5; 7.5 and 10 kGy with concentration of MMA 25; 50; 75; and 100 phr (Part Hundred Ratio of Rubber) expectially and optimazation condition of the adhesive process all the production of canvas shoes have been carried out. The properties of NRL-g-MMA and its rubber such as total solid contain, viscosity, pH, modulus, tensile, strenght, hardnes, elongation at break, and adhesive strenght for producting canvas shoes where evaluated. The at adhesive results show that NRL-g-MMA with the 75 phr of MMA and iradiation dose 5 kGy is adhesive will good stability during storage. The adhesive strenght of shoes its 16-18 N/6mm, more here than SNI 1-0172-1987 with the value 10N/6mm. Besic there is a tendency that adhesive strengt of product shoes at rome temperature (30-50 o C). stronger than at high temperature (100 o C)

  16. The Effect Of Gamma Irradiation And CaCO3 On The Physical And Mechanical Properties Of Natural Rubber (NR) Compound

    International Nuclear Information System (INIS)

    Iskandar, Sudrajat; Marliyanti, Isni; Kadariyah; Kardha, Made Sumarti

    2000-01-01

    The characterization of the effect of gamma irradiation and CaCO 3 on the physical and mechanical properties of NR compound (NRC) have been started. The NRC was made by blending of NR and low density polyethylene (LDPE), carbon black, additives (stearic acid, ZnO, irganox 1076, paraffin wax and minarex B oil) in certain amount and CaCO 3 with various composition of 33,67 and 100 phr (part per hundred ratio of rubber) using hot roll mill at 120 deg C and 100 deg C of front and back roll respectively. For making film, film, the NRC was then pressed by hot and cold press machine at 135 deg C and at room temperature respectively for about 3 minutes. The film was then irradiated with gamma rays at 150, 300, and 500 kGy. Characterization was done according to the Indonesian National Standard (SNI) The experimental results showed that by increasing the irradiation dose, the aging resistance, tensile strength, elongation at break, solvent xylene resistance, tear strength and hardness of natural rubber compound increased. While by increasing the CaCO 3 content, the hardness and specific gravity of irradiated NRC. Were increased. But the tensile strength, elongation at break and tear strength of irradiated NRC decreased According to SNI no 12-1000-1989 and SII 0944-84 that the experiment results may possible to used for making shoe sole and rubber carpet

  17. PROPERTIES TYRE TREAD RUBBERS DEPENDING ON PARTICULARITY OF RUBBER COMPOUND

    Directory of Open Access Journals (Sweden)

    Z. S. Shashok

    2014-01-01

    Full Text Available Summary. The results of studies of the elastomeric compositions based on natural rubber containing curatives different ratio "curing agent : vulcanization accelerator" listed in this article. Influence of the composition of the vulcanizing group on stress-strain and elastic- deformation properties of tire tread rubber was installed. It has been shown that a significant effect on thermo-oxidative aging of vulcanizates was the composition of the vulcanizing group. Results of studies resistance tread rubber to exposure to elevated temperatures were presented . Vulcanizates differing type and density by varying the cross-linking ratio of "curing agent : vulcanization accelerator" were obtained . Research results in the formation of rubber resistance and crack growth at different temperatures were presented. Revealed that the best education and resistance to tear propagation under normal conditions characterized by rubber ratio "curing agent : vulcanization accelerator" equal to 1.5:1. It has been established that a dynamic endurance study rubbers depends largely on the nature and concentration of the cross-linking cross-links and movable promote increase efficiency due to the grid and reduce the sulfidity rearrangement. During loading mode alternating deformations at elevated temperatures lability of polysulfide bonds negatively affects the performance of rubber, and the decisive role of providing strength and thermal cross-linking. It is shown that the performance of the spatial grid rubbers allow indirectly judge the dynamic vulcanizates endurance and predict performance rubbers at elevated temperatures under conditions of repeated cyclic deformation. Revealed that the vulcanizing system containing sulfur and vulcanization accelerator TBBS 1:2, promotes the formation of the optimal structure of vulcanized rubber , which provides the best resistance to repeated cyclic deformations in the operating temperatures of the tire.

  18. Characteristics Buton Natural Asphalt-Rubber (BNA-R on the Performance Improvement of Warm Mix Asphalt Using Natural Zeolite

    Directory of Open Access Journals (Sweden)

    Wahjuningsih Nurul

    2018-01-01

    Full Text Available The decrease in the ability of service of pavement can be caused by the durability factor in the pavement layer in receiving heavy traffic load and the temperature of the pavement. Permanent deformation is one of the criteria of failure of asphalt mixture. Performance assessment of the asphalt mixture can be observed from the rheological properties of asphalt binder. The use of BNA-R in this study is intended to modify the characteristics of bitumen penetration grade 60 / 70 used in warm mix asphalt. Warm mix asphalt with lower temperatures of mixing and compaction than conventional asphalt mixtures was chosen because it is more environmentally friendly. To reduce the temperature in this warm asphalt technology is achieved by using natural zeolite. Both of these materials are local materials that are widely available in Indonesia. The rheology of asphalt 60/70 modified with BNA-R indicates that the addition of BNA-R in the base asphalt increase the complex modulus value and decrease the phase angle value. These values were related to the performance of mixture in the permanent deformation criteria. Reducing the temperature of mixing and compaction should be balanced with modifying the asphalt binder used. Rutting due to permanent deformation can resulted in inconvenience to the passengers and can lead to high costs of road maintenance. To determine the permanent deformation of asphalt mix with material combinations was performed through the wheel tracking test machine with 3,780 cycles for 3 hours. The results shows that after test track over 7 thousand passes have seen permanent deformation characteristics of asphalt concrete mixture with a variation of the characteristics of bitumen.

  19. Characteristics Buton Natural Asphalt-Rubber (BNA-R) on the Performance Improvement of Warm Mix Asphalt Using Natural Zeolite

    Science.gov (United States)

    Wahjuningsih, Nurul; Pranowo Hadiwardoyo, Sigit; Jachrizal Sumabrata, R.

    2018-03-01

    The decrease in the ability of service of pavement can be caused by the durability factor in the pavement layer in receiving heavy traffic load and the temperature of the pavement. Permanent deformation is one of the criteria of failure of asphalt mixture. Performance assessment of the asphalt mixture can be observed from the rheological properties of asphalt binder. The use of BNA-R in this study is intended to modify the characteristics of bitumen penetration grade 60 / 70 used in warm mix asphalt. Warm mix asphalt with lower temperatures of mixing and compaction than conventional asphalt mixtures was chosen because it is more environmentally friendly. To reduce the temperature in this warm asphalt technology is achieved by using natural zeolite. Both of these materials are local materials that are widely available in Indonesia. The rheology of asphalt 60/70 modified with BNA-R indicates that the addition of BNA-R in the base asphalt increase the complex modulus value and decrease the phase angle value. These values were related to the performance of mixture in the permanent deformation criteria. Reducing the temperature of mixing and compaction should be balanced with modifying the asphalt binder used. Rutting due to permanent deformation can resulted in inconvenience to the passengers and can lead to high costs of road maintenance. To determine the permanent deformation of asphalt mix with material combinations was performed through the wheel tracking test machine with 3,780 cycles for 3 hours. The results shows that after test track over 7 thousand passes have seen permanent deformation characteristics of asphalt concrete mixture with a variation of the characteristics of bitumen.

  20. Natural Fiber Reinforced Composites: A Review on Potential for Corrugated Core of Sandwich Structures

    Directory of Open Access Journals (Sweden)

    Jusoh A.F.

    2016-01-01

    Full Text Available Natural fibers, characterized by sustainability, have gained a considerable attention in recent years, due to their advantages of environmental acceptability and commercial viability. In this paper, the characterization of natural fibers including the mechanical properties and alkalization of fibers is presented. Most recent study had gone through the mercerization process to improve the toughness of natural fibers; which is a well-known hydrophilic material. Traditional reinforcement method was commonly used to fabricate a natural fiber composite such as hand lay-up and mold press due to its convenience in terms of time and cost. Also, different kind of matrix material used in different kind of natural fibers gave high impact on the tensile and flexural test result. By selecting appropriate chemical treatment, matrix material and fabrication method, the tensile and flexural test gives different results and findings. As most researchers tend to use metals to create corrugated cores for sandwich structure, it is possible to develop this structure using natural fibers such as kenaf, wood dust, and other natural fibers.