Sorption Isotherm of Southern Yellow Pine—High Density Polyethylene Composites

Directory of Open Access Journals (Sweden)

Feihong Liu

2015-01-01

Full Text Available Temperature and relative humidity (RH are two major external factors, which affect equilibrium moisture content (EMC of wood-plastic composites (WPCs. In this study, the effect of different durability treatments on sorption and desorption isotherms of southern yellow pine (SYP-high density polyethylene (HDPE composites was investigated. All samples were equilibriumed at 20 °C and various RHs including 16%, 33%, 45%, 66%, 75%, 85%, 93%, and100%. EMCs obtained from desorption and absorption for different WPC samples were compared with Nelson’s sorption isotherm model predictions using the same temperature and humidity conditions. The results indicated that the amount of moisture absorbed increased with the increases in RH at 20 °C. All samples showed sorption hysteresis at a fixed RH. Small difference between EMC data of WPC samples containing different amount of ultraviolet (UV stabilizers were observed. Similar results were observed among the samples containing different amount of zinc borate (ZB. The experimental data of EMCs at various RHs fit to the Nelson’s sorption isotherm model well. The Nelson’s model can be used to predicate EMCs of WPCs under different RH environmental conditions.

A novel wood flour-filled composite based on microfibrillar high-density polyethylene (HDPE)/Nylon-6 blends.

Science.gov (United States)

Liu, Hongzhi; Yao, Fei; Xu, Yanjun; Wu, Qinglin

2010-05-01

A novel wood flour (WF)-filled composite based on the microfibrillar high-density polyethylene (HDPE) and Nylon-6 co-blend, in which both in situ formed Nylon-6 microfibrils and WF acted as reinforcing elements, was successfully developed using a two-step extrusion method. At the 30wt.% WF loading level, WF-filled composite based on the microfibrillized HDPE/Nylon-6 blend exhibited higher strengths and moduli than the corresponding HDPE-based composite. The incorporation of WF reduced short-term creep response of HDPE matrix and the presence of Nylon-6 microfibrils further contributed to the creep reduction. Copyright 2009 Elsevier Ltd. All rights reserved.

The Mechanical Properties of Recycled Polyethylene-Polyethylene Terephthalate Composites

Directory of Open Access Journals (Sweden)

Ehsan Avazverdi

2015-02-01

Full Text Available Polyethylene terephthalate (PET, one of the thermoplastic polymers, is encountered with arduous problems in its recycling. After recycling, its mechanical properties drop dramatically and therefore it cannot be used to produce the products as virgin PET does. Polyethylene is a thermoplastic polymer which can be easily recycled using the conventional recycling processes. The decreased mechanical properties of virgin polyethylene due to the environmental factors can be improved by reinforcing fillers. In this paper, we studied the effects of adding recycled polyethylene terephthalate (rPET as a filler, in various amounts with different sizes, on the physical and mechanical properties of recycled polyethylene. Composite samples were prepared using an internal mixer at temperature 185°C, well below rPET melting point (250°C, and characterized by their mechanical properties. To improve the compatibility between different components, PE grafted with maleic anhydride was added as a coupling agent in all the compositions under study. The mechanical properties of the prepared samples were performed using the tensile strength, impact strength, surface hardness and melt flow index (MFI tests. To check the dispersity of the polyethylene terephthalate powder in the polyethylene matrix, light microscopy was used. The results showed that the addition of rPET improved the tensile energy, tensile modulus and surface hardness of the composites while reduced the melt flow index, elongation-at-yield, tensile strength and fracture energy of impact test. We could conclude that with increasing rPET percentage in the recycled polyethylene matrix, the composite became brittle, in other words it decreased the plastic behavior of recycled polyethylene. Decreasing particle size led to higher surface contacts, increased the mechanical properties and made the composite more brittle. The light microscopy micrographs of the samples showed a good distribution of small r

Biomimetic porous high-density polyethylene/polyethylene- grafted-maleic anhydride scaffold with improved in vitro cytocompatibility.

Science.gov (United States)

Sharma, Swati; Bhaskar, Nitu; Bose, Surjasarathi; Basu, Bikaramjit

2018-05-01

A major challenge for tissue engineering is to design and to develop a porous biocompatible scaffold, which can mimic the properties of natural tissue. As a first step towards this endeavour, we here demonstrate a distinct methodology in biomimetically synthesized porous high-density polyethylene scaffolds. Co-extrusion approach was adopted, whereby high-density polyethylene was melt mixed with polyethylene oxide to form an immiscible binary blend. Selective dissolution of polyethylene oxide from the biphasic system revealed droplet-matrix-type morphology. An attempt to stabilize such morphology against thermal and shear effects was made by the addition of polyethylene- grafted-maleic anhydride as a compatibilizer. A maximum ultimate tensile strength of 7 MPa and elastic modulus of 370 MPa were displayed by the high-density polyethylene/polyethylene oxide binary blend with 5% maleated polyethylene during uniaxial tensile loading. The cell culture experiments with murine myoblast C2C12 cell line indicated that compared to neat high-density polyethylene and high-density polyethylene/polyethylene oxide, the high-density polyethylene/polyethylene oxide with 5% polyethylene- grafted-maleic anhydride scaffold significantly increased muscle cell attachment and proliferation with distinct elongated threadlike appearance and highly stained nuclei, in vitro. This has been partly attributed to the change in surface wettability property with a reduced contact angle (∼72°) for 5% PE- g-MA blends. These findings suggest that the high-density polyethylene/polyethylene oxide with 5% polyethylene- grafted-maleic anhydride can be treated as a cell growth substrate in bioengineering applications.

Preparation and characterization of high density polyethylene and residual fibre of Attalea funifera Mart (piacava) composites

International Nuclear Information System (INIS)

Agrela, Sara P.; Guimaraes, Danilo H.; Jose, Nadia M.; Carvalho, Gleidson G.P.; Carvalho, Ricardo F.

2009-01-01

The use of natural fiber reinforcement thermoplastic polymer is continuously increasing. This fact is manly due to its advantages as low cost, availability, recyclability, low energy demand and then environmental appeal if compared to synthetics fibers. The composites were prepared in different fiber volume ratios (5%, 10% and 20%) mixed with high density polyethylene (HDPE) and heated at 190 deg C. Thermogravimetric analysis and differential scanning calorimetry were used to investigate thermal stability. The composites structure was characterized by Fourier Transform Infrared spectroscopy, X-ray diffractometry. Fiber and residue of piassava (Attalea funifera Mart) chemical composition were determined by Van Soest Method. The results indicate that thermo stability of the composites of HDPE prepared with fiber volume ratios up to 20% is only slightly lowered. (author)

Wood plastic composites based on microfibrillar blends of high density polyethylene/poly(ethylene terephthalate).

Science.gov (United States)

Lei, Yong; Wu, Qinglin

2010-05-01

High-melting-temperature poly(ethylene terephthalate) (PET) was successfully introduced into wood plastic composites through a two-step reactive extrusion technology. Wood flour was added into pre-prepared PET/high density polyethylene (HDPE) microfibrillar blends (MFBs) in the second extrusion at the temperature for processing HDPE. Addition of 25% in situ formed PET microfibers obviously increased the mechanical properties of HDPE, and more significant enhancement by the in situ formed recycled PET microfibers was observed for the recycled HDPE. Adding 2% E-GMA improved the compatibility between matrix and microfibers in MFBs, resulting further enhanced mechanical properties. The subsequent addition of 40% wood flour did not influence the size and morphology of PET microfibers, and improved the comprehensive mechanical properties of MFBs. The wood flour increased the crystallinity level of HDPE in the compatibilized MFB in which PET phase did not crystallize. The storage modulus of MFB was greatly improved by wood flour. Published by Elsevier Ltd.

Extrudable polymer-polymer composites based on ultra-high molecular weight polyethylene

Science.gov (United States)

Panin, S. V.; Kornienko, L. A.; Alexenko, V. O.; Buslovich, D. G.; Dontsov, Yu. V.

2017-12-01

Mechanical and tribotechnical characteristics of polymer-polymeric composites of UHMWPE are studied with the aim of developing extrudable, wear-resistant, self-lubricant polymer mixtures for Additive Manufacturing (AM). The motivation of the study is their further application as feedstocks for 3D printing. Blends of UHMWPE with graft- and block copolymers of low-density polyethylene (HDPE-g-VTMS, HDPE-g-SMA, HDPE-b-EVA), polypropylene (PP), block copolymers of polypropylene and polyamide with linear low density polyethylene (PP-b-LLDPE, PA-b-LLDPE), as well as cross-linked polyethylene (PEX-b), are examined. The choice of compatible polymer components for an ultra- high molecular weight matrix for increasing processability (extrudability) is motivated by the search for commercially available and efficient additives aimed at developing wear-resistant extrudable polymer composites for additive manufacturing. The extrudability, mechanical properties and wear resistance of UHMWPE-based polymer-polymeric composites under sliding friction with different velocities and loads are studied.

High-Density Polyethylene and Heat-Treated Bamboo Fiber Composites: Nonisothermal Crystallization Properties

Directory of Open Access Journals (Sweden)

Yanjun Li

2015-01-01

Full Text Available The effect of heat-treated bamboo fibers (BFs on nonisothermal crystallization of high-density polyethylene (HDPE was investigated using differential scanning calorimetry under nitrogen. The Avrami-Jeziorny model was used to fit the measured crystallization data of the HDPE/BF composites and to obtain the model parameters for the crystallization process. The heat flow curves of neat HDPE and HDPE/heat-treated BF composites showed similar trends. Their crystallization mostly occurred within a temperature range between 379 K and 399 K, where HDPE turned from the liquid phase into the crystalline phase. Values of the Avrami exponent (n were in the range of 2.8~3.38. Lamellae of neat HDPE and their composites grew in a three-dimensional manner, which increased with increased heat-treatment temperature and could be attributed to the improved ability of heterogeneous nucleation and crystallization completeness. The values of the modified kinetic rate constant (KJ first increased and then decreased with increased cooling rate because the supercooling was improved by the increased number of nucleating sites. Heat-treated BF and/or a coupling agent could act as a nucleator for the crystallization of HDPE.

Potential of Using Recycled Low-Density Polyethylene in Wood Composites Board

Directory of Open Access Journals (Sweden)

A. C. Igboanugo

2011-03-01

Full Text Available The aim of this study was to investigate the suitability of using recycled low density polyethylene (RLDPE in wood board manufacturing. The composite board was produced by compressive moulding by increasing the percentage LDPE from 30 to 50wt% with interval of 10wt% at a temperatures of 140 and 180oC, pressure of 30-40 Kg/cm2 and pressing time 7-13minutes. The microstructure and mechanical properties: modulus of rupture (MOR, modulus of elasticity (MOE, Tensile strength, impact strength properties of boards were determined. The results showed that high modulus of rupture of 20.31N/mm2and MOE of 1363N/mm2 were obtained from board produced at 140oC, 60/40wt% wood particles/LDPE content. The uniform distribution of the particles and the recycled LDPE in the microstructure of the composites board is the major factor responsible for the improvement in the mechanical properties. The results showed that the MOE, MOR meets the minimum requirements of the European standards, for general purpose. The boards produced had tensile strength that is within the requirement. Hence this LDPE can be used in board production for general purpose applications.

Effects of Boron Compounds on the Mechanical and Fire Properties of Wood-chitosan and High-density Polyethylene Composites

Directory of Open Access Journals (Sweden)

Guo-Fu Wu

2014-05-01

Full Text Available Wood-plastic composites (WPCs represent a growing class of durable, low-maintenance construction materials whose use can decrease dependence on petroleum. High-density polyethylene (HDPE, chitosan (CS, wood flour (WF, boric acid (BA, and borax (BX, as well as maleic anhydride grafted polyethylene (MAPE and polyethylene wax (PE wax, were used to develop a durable wood-plastic composite (WPC using the extrusion method. The effects of boron compounds (3%, 6%, 9%, or 12% by weight BA/BX on the mechanical and fire properties of the WPCs were investigated. Mechanical testing indicated that as the percentage weight of boron compounds increased, the flexural modulus, flexural strength, and tensile strength significantly decreased. Cone calorimeter tests were used to characterize the fire performance of the WPCs, and these results suggested that adding BA/BX compounds to WPCs modestly improved the fire performance. As the percentage weight of BA/BX increased from 3% to 9%, the time to ignition (TTI, heat release rate (HRR, total heat release rate (HRR-Total, smoke production rate (SPR, and specific extinction area (SEA of the WPCs were all reduced.

Curaua fiber reinforced high-density polyethylene composites: effect of impact modifier and fiber loading

Directory of Open Access Journals (Sweden)

Jaqueline Albano de Morais

Full Text Available Abstract Short fibers are used in thermoplastic composites to increase their tensile and flexural resistance; however, it often decreases impact resistance. Composites with short vegetal fibers are not an exception to this behavior. The purpose of this work is to produce a vegetal fiber reinforced composite with improved tensile and impact resistance in relation to the polymer matrix. We used poly(ethylene-co-vinyl acetate, EVA, to recover the impact resistance of high density polyethylene, HDPE, reinforced with Curauá fibers, CF. Blends and composites were processed in a corotating twin screw extruder. The pure polymers, blends and composites were characterized by differential scanning calorimetry, thermogravimetry, infrared spectroscopy, scanning electron microscopy, tensile mechanical properties and Izod impact resistance. EVA used as impact modifier in the HDPE matrix exhibited a co-continuous phase and in the composites the fibers were homogeneously dispersed. The best combination of mechanical properties, tensile, flexural and impact, were obtained for the formulations of composites with 20 wt. % of CF and 20 to 40 wt. % of EVA. The composite prepared with 20 wt. % EVA and containing 30 wt. % of CF showed impact resistance comparable to pure HDPE and improved tensile and flexural mechanical properties.

Electric anisotropy in high density polyethylene + carbon black composites induced by mechanical deformation

Energy Technology Data Exchange (ETDEWEB)

Vigueras-Santiago, E; Hernandez-Lopez, S; Camacho-Lopez, M A; Lara-Sanjuan, O, E-mail: eviguerass@uaemex.m [Laboratorio de Investigacion y Desarrollo de Materiales Avanzados (LIDMA), Facultad de Quimica, UAEM. Paseo Colon esq. con Paseo Tollocan, s/n. C.P. 50000, Toluca (Mexico)

2009-05-01

High density polyethylene + carbon black composites with electrical anisotropy was studied. Electrical anisotropy was induced by uniaxial mechanical deformation and injection moulding. We show that anisotropy depends on the carbon black concentration and percentage deformation. Resistivity had the highest anisotropy resistivity around the percolation threshold. Perpendicular resistivity showed two magnitude orders higher than parallel resistivity for injected samples, whereas resistivity showed an inverse behaviour for 100% tensile samples. Both directions were set respect to the deformation axe. Anisotropy could be explained in terms of the molecular deformation (alignment) of the polymer chains as a response of the deformation process originating a redistribution of the carbon black particles in both directions. Alignment of the polymer chains was evidenced by polarized Raman spectroscopy.

Morphology-Property relationship of high density Polyethylene/Hevea Brasiliensis Leaves/Imperata cylindrica hybrid composite: Impact strength

Science.gov (United States)

Rashidi, A. R.; Muhammad, A.; Roslan, A.

2017-09-01

This research studies about the Hevea Brasiliensis Leaves and Imperata Cylindrica that was used as filler in High Density Polyethylene (HDPE). The fillers content were varied in the composite by 5 wt%, 15 wt% and 25 wt% respectively. This polymer composite are being studied by using Impact Test and Scanning Electron Microscopy (SEM). The analysis show that the impact strength value increased when the percent of bio filler used is low. The result between pure HDPE and the composites shows an outcome of significant changes in impact energy values, while the values between different composite change slightly. A composite that contained 5 wt% of fillers is the better energy absorber than 15 wt% and 25 wt% according to impact testing. In addition, the morphology studies on the composite sample show that the bio-filler was successfully embedded. Overall, these finding suggest that HBL and IC can be an alternative filler to be incorporated in polymer matrix.

Mechanical, Morphological, and Thermal Properties of Nutshell and Microcrystalline Cellulose Filled High-Density Polyethylene Composites

Directory of Open Access Journals (Sweden)

Sevda Boran

2016-01-01

Full Text Available Effects of nutshell fiber loadings of 30 wt.% and MCC loadings up to 15 wt.% on some properties of high-density polyethylene composites (HDPE were investigated. The composites were manufactured by a single screw extruder and injection molding. The experimental composite samples were tested for their mechanical performance including tensile strength, tensile modulus, flexural strength, flexural modulus, and impact strength. Thermal and morphological properties of the composites were tested by differential scanning calorimetry-DSC and scanning electron microscopy (SEM, respectively. The maximum tensile strength was obtained from the MCC-filled composites, whereas the maximum flexural strength was achieved with the MCC-nutshell filled composites. The tensile and flexural moduli of the composites were significantly improved with increasing MCC content and the presence of nutshell fibers in polymer matrix. Impact strength decreased using MCC and nutshell fiber in the polymer matrix. Based on the DSC results, there was no remarkable change in the melting point for all composites. The results showed that the incorporation of nutshell fibers and MCC in the polymer matrix had brought about some positive effect on mechanical properties of HDPE composites.

Mechanical and electrical properties of low density polyethylene filled with carbon nanotubes

International Nuclear Information System (INIS)

Sabet, Maziyar; Soleimani, Hassan

2014-01-01

Carbon nanotubes (CNTs) reveal outstanding electrical and mechanical properties in addition to nanometer scale diameter and high aspect ratio, consequently, making it an ideal reinforcing agent for high strength polymer composites. Low density polyethylene (LDPE)/CNT composites were prepared via melt compounding. Mechanical and electrical properties of (LDPE)/CNT composites with different CNT contents were studied in this research

Raman structural study of melt-mixed blends of isotactic polypropylene with polyethylene of various densities

Science.gov (United States)

Prokhorov, K. A.; Nikolaeva, G. Yu; Sagitova, E. A.; Pashinin, P. P.; Guseva, M. A.; Shklyaruk, B. F.; Gerasin, V. A.

2018-04-01

We report a Raman structural study of melt-mixed blends of isotactic polypropylene with two grades of polyethylene: linear high-density and branched low-density polyethylenes. Raman methods, which had been suggested for the analysis of neat polyethylene and isotactic polypropylene, were modified in this study for quantitative analysis of polyethylene/polypropylene blends. We revealed the dependence of the degree of crystallinity and conformational composition of macromolecules in the blends on relative content of the blend components and preparation conditions (quenching or annealing). We suggested a simple Raman method for evaluation of the relative content of the components in polyethylene/polypropylene blends. The degree of crystallinity of our samples, evaluated by Raman spectroscopy, is in good agreement with the results of analysis by differential scanning calorimetry.

Preparation and properties of banana fiber-reinforced composites based on high density polyethylene (HDPE)/Nylon-6 blends.

Science.gov (United States)

Liu, H; Wu, Q; Zhang, Q

2009-12-01

Banana fiber (BaF)-filled composites based on high density polyethylene (HDPE)/Nylon-6 blends were prepared via a two-step extrusion method. Maleic anhydride grafted styrene/ethylene-butylene/styrene triblock polymer (SEBS-g-MA) and maleic anhydride grafted polyethylene (PE-g-MA) were used to enhance impact performance and interfacial bonding between BaF and the resins. Mechanical, crystallization/melting, thermal stability, water absorption, and morphological properties of the composites were investigated. In the presence of SEBS-g-MA, better strengths and moduli were found for HDPE/Nylon-6 based composites compared with corresponding HDPE based composites. At a fixed weight ratio of PE-g-MA to BaF, an increase of BaF loading up to 48.2 wt.% led to a continuous improvement in moduli and flexural strength of final composites, while impact toughness was lowered gradually. Predicted tensile modulus by the Hones-Paul model for three-dimensional random fiber orientation agreed well with experimental data at the BaF loading of 29.3 wt.%. However, the randomly-oriented fiber models underestimated experimental data at higher fiber levels. It was found that the presence of SEBS-g-MA had a positive influence on reinforcing effect of the Nylon-6 component in the composites. Thermal analysis results showed that fractionated crystallization of the Nylon-6 component in the composites was induced by the addition of both SEBS-g-MA and PE-g-MA. Thermal stability of both composite systems differed slightly, except an additional decomposition peak related to the minor Nylon-6 for the composites from the HDPE/Nylon-6 blends. In the presence of SEBS-g-MA, the addition of Nylon-6 and increased BaF loading level led to an increase in the water absorption value of the composites.

Effects of gamma irradiation on polypropylene, polypropylene + high density polyethylene and polypropylene + high density polyethylene + wood flour

Energy Technology Data Exchange (ETDEWEB)

Reyes, J.; Albano, C.; Davidson, E.; Poleo, R. [Universidad Central de Venezuela, Caracas (Venezuela). Escuela de Quimica; Gonzalez, J.; Ichazo, M. [Universidad Simon Bolivar, Dept. de Mecanica, Caracas (Venezuela); Chipara, M. [Research Institute for Electrotechnics, Bucharest (Romania)

2001-04-01

The effect of the gamma-irradiation on the mechanical properties of the composites, Polypropylene (PP), PP+high density Polyethylene (HDPE), PP+ HDPE+wood flour, where HDPE is virgin and recycled, was studied. This paper discusses the behavior of the composites after exposure to various doses of gamma irradiation (1-7 MRads) in the presence of oxygen. The dependence of mechanical properties on the integral dose for a constant dose rate of 0.48 MRads/h confirms the influence of the irradiation. Strong effects on the elongation at break and break strength is noticed. The mathematical analysis suggests for the PP+r-HDPE a bimolecular process of the elongation at break. On the order hand, for the PP+HDPE a complex process is represented for a three exponential equation. (orig.)

Effects of gamma irradiation on polypropylene, polypropylene + high density polyethylene and polypropylene + high density polyethylene + wood flour

International Nuclear Information System (INIS)

Reyes, J.; Albano, C.; Davidson, E.; Poleo, R.; Chipara, M.

2001-01-01

The effect of the gamma-irradiation on the mechanical properties of the composites, Polypropylene (PP), PP+high density Polyethylene (HDPE), PP+ HDPE+wood flour, where HDPE is virgin and recycled, was studied. This paper discusses the behavior of the composites after exposure to various doses of gamma irradiation (1-7 MRads) in the presence of oxygen. The dependence of mechanical properties on the integral dose for a constant dose rate of 0.48 MRads/h confirms the influence of the irradiation. Strong effects on the elongation at break and break strength is noticed. The mathematical analysis suggests for the PP+r-HDPE a bimolecular process of the elongation at break. On the order hand, for the PP+HDPE a complex process is represented for a three exponential equation. (orig.)

Characterisation of Cassava Bagasse and Composites Prepared by Blending with Low-Density Polyethylene

Directory of Open Access Journals (Sweden)

Fabiane Oliveira Farias

2014-12-01

Full Text Available The main objective of this study was to characterise the cassava bagasse and to evaluate its addition in composites. Two cassava bagasse samples were characterised using physicochemical, thermal and microscopic techniques, and by obtaining their spectra in the mid-infrared region and analysing them by using x-ray diffraction. Utilising sorption isotherms, it was possible to establish the acceptable conditions of temperature and relative humidity for the storage of the cassava bagasse. The incorporation of cassava bagasse in a low-density polyethylene (LDP matrix was positive, increasing the elasticity modulus values from 131.90 for LDP to 186.2 for 70% LDP with 30% SP bagasse. These results were encouraging because cassava bagasse could serve as a structural reinforcement, as well as having environmental advantages for its application in packaging, construction and automotive parts.

Linear low density polyethylene (LLDPE) and lamellar zirconium phosphate (Zr P) composites: morphology and mechanical properties

International Nuclear Information System (INIS)

Silva, Daniela F.; Mandes, Luis C.; Lino, Adan S.

2011-01-01

Composites of linear low density polyethylene (LLDPE) and zirconium phosphate (ZrP) were prepared by extrusion in the molten state, containing 2 (w%) of the lamellar filler. The filler was previously synthesized by direct precipitation method and characterized. After processing, the composite and the pure virgin polymer were molded by compression in order to obtain films of 1 mm thick which were characterized by X-ray diffraction at high angle (WAXD), stress-strain mechanical analysis and scanning electron microscopy (SEM). The WAXD and SEM analysis showed that there was no intercalation of LLDPE in zirconium phosphate, possibly due to the fact that the layers do not have spacing enough to allow the intercalation of polymer chains in the galleries of the filler and thus allow the exfoliation. (author)

Dynamic mechanical analysis of compatibilizer effect on the mechanical properties of wood flour/high-density polyethylene composites

Science.gov (United States)

Mehdi Behzad; Medhi Tajvidi; Ghanbar Ehrahimi; Robert H. Falk

2004-01-01

In this study, effect of MAPE (maleic anhydride polyethylene) as the compatibilizer on the mechanical properties of wood-flour polyethylene composites has been investigated by using Dynamic Mechanical Analysis (DMA). Composites were made at 25% and 50% by weight fiber contents and 1% and 2% compatibilizer respectively. Controls were also made at the same fiber contents...

High Density Polyethylene Composites Reinforced with Hybrid Inorganic Fillers: Morphology, Mechanical and Thermal Expansion Performance

Directory of Open Access Journals (Sweden)

Birm-June Kim

2013-09-01

Full Text Available The effect of individual and combined talc and glass fibers (GFs on mechanical and thermal expansion performance of the filled high density polyethylene (HDPE composites was studied. Several published models were adapted to fit the measured tensile modulus and strength of various composite systems. It was shown that the use of silane-modified GFs had a much larger effect in improving mechanical properties and in reducing linear coefficient of thermal expansion (LCTE values of filled composites, compared with the use of un-modified talc particles due to enhanced bonding to the matrix, larger aspect ratio, and fiber alignment for GFs. Mechanical properties and LCTE values of composites with combined talc and GF fillers varied with talc and GF ratio at a given total filler loading level. The use of a larger portion of GFs in the mix can lead to better composite performance, while the use of talc can help lower the composite costs and increase its recyclability. The use of 30 wt % combined filler seems necessary to control LCTE values of filled HDPE in the data value range generally reported for commercial wood plastic composites. Tensile modulus for talc-filled composite can be predicted with rule of mixture, while a PPA-based model can be used to predict the modulus and strength of GF-filled composites.

High Density Polyethylene Composites Reinforced with Hybrid Inorganic Fillers: Morphology, Mechanical and Thermal Expansion Performance.

Science.gov (United States)

Huang, Runzhou; Xu, Xinwu; Lee, Sunyoung; Zhang, Yang; Kim, Birm-June; Wu, Qinglin

2013-09-17

The effect of individual and combined talc and glass fibers (GFs) on mechanical and thermal expansion performance of the filled high density polyethylene (HDPE) composites was studied. Several published models were adapted to fit the measured tensile modulus and strength of various composite systems. It was shown that the use of silane-modified GFs had a much larger effect in improving mechanical properties and in reducing linear coefficient of thermal expansion (LCTE) values of filled composites, compared with the use of un-modified talc particles due to enhanced bonding to the matrix, larger aspect ratio, and fiber alignment for GFs. Mechanical properties and LCTE values of composites with combined talc and GF fillers varied with talc and GF ratio at a given total filler loading level. The use of a larger portion of GFs in the mix can lead to better composite performance, while the use of talc can help lower the composite costs and increase its recyclability. The use of 30 wt % combined filler seems necessary to control LCTE values of filled HDPE in the data value range generally reported for commercial wood plastic composites. Tensile modulus for talc-filled composite can be predicted with rule of mixture, while a PPA-based model can be used to predict the modulus and strength of GF-filled composites.

A NOVEL FIRE RETARDANT AFFECTS FIRE PERFORMANCE AND MECHANICAL PROPERTIES OF WOOD FLOUR-HIGH DENSITY POLYETHYLENE COMPOSITES

Directory of Open Access Journals (Sweden)

Mingzhu Pan,

2012-02-01

Full Text Available Wood flour-high density polyethylene (HDPE composites were prepared to investigate the effects of ammonium polyphosphate based fire retardant content (2, 4, 6, 8, and 10-wt%, on the flammability, mechanical, and morphological properties of the wood flour-HDPE composites in this study. Cone calorimetry analysis showed that the addition of fire retardant could decrease the heat release rate (HRR and total smoke release of wood flour-HDPE composites, while it had no obviously effects on effective heat of combustion. Most of the decrease of the HRR occurred with the concentration of the fire retardant up to 4-wt%. With addition of fire retardant, the composites showed a decrease in tensile elongation at break and impact strength, and had no obvious effect on tensile and flexural strength. The scanning electron microscopy observation on the fracture surface of the composites indicated that fire retardant had a uniform dispersion in the wood flour-HDPE composites. However, interfacial bonding would be suggested to improve in wood flour-HDPE composites with ammonium polyphosphate based fire retardant.

Mechanical, Rheological, and Bioactivity Properties of Ultra High-Molecular-Weight Polyethylene Bioactive Composites Containing Polyethylene Glycol and Hydroxyapatite

Directory of Open Access Journals (Sweden)

Mazatusziha Ahmad

2012-01-01

Full Text Available Ultrahigh-molecular-weight polyethylene/high-density polyethylene (UHMWPE/HDPE blends prepared using polyethylene glycol PEG as the processing aid and hydroxyapatite (HA as the reinforcing filler were found to be highly processable using conventional melt blending technique. It was demonstrated that PEG reduced the melt viscosity of UHMWPE/HDPE blend significantly, thus improving the extrudability. The mechanical and bioactive properties were improved with incorporation of HA. Inclusion of HA from 10 to 50 phr resulted in a progressive increase in flexural strength and modulus of the composites. The strength increment is due to the improvement on surface contact between the irregular shape of HA and polymer matrix by formation of mechanical interlock. The HA particles were homogenously distributed even at higher percentage showed improvement in wetting ability between the polymer matrix and HA. The inclusion of HA enhanced the bioactivity properties of the composite by the formation of calcium phosphate (Ca-P precipitates on the composite surface as proven from SEM and XRD analysis.

Fabrication, characterization and gamma rays shielding properties of nano and micro lead oxide-dispersed-high density polyethylene composites

Science.gov (United States)

Mahmoud, Mohamed E.; El-Khatib, Ahmed M.; Badawi, Mohamed S.; Rashad, Amal R.; El-Sharkawy, Rehab M.; Thabet, Abouzeid A.

2018-04-01

Polymer composites of high-density polyethylene (HD-PE) filled with powdered lead oxide nanoparticles (PbO NPs) and bulk lead oxide (PbO Blk) were prepared with filler weight fraction [10% and 50%]. These polymer composites were investigated for radiation-shielding of gamma-rays emitted from radioactive point sources [241Am, 133Ba, 137Cs, and 60Co]. The polymer was found to decrease the heaviness of the shielding material and increase the flexibility while the metal oxide fillers acted as principle radiation attenuators in the polymer composite. The prepared composites were characterized by Fourier transform infrared spectrophotometer (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscope (SEM), Brunauer-Emmett-Teller surface area (BET) and field emission transmission electron microscope (FE-TEM). The morphological analysis of the assembled composites showed that, PbO NPs and PbO Blk materials exhibited homogenous dispersion in the polymer-matrix. Thermogravimetric analysis (TGA) demonstrated that the thermal-stability of HD-PE was enhanced in the presence of both PbO Blk and PbO NPs. The results declared that, the density of polymer composites was increase with the percentage of filler contents. The highest density value was identified as 1.652 g cm-3 for 50 wt% of PbO NPs. Linear attenuation coefficients (μ) have been estimated from the use of XCOM code and measured results. Reasonable agreement was attended between theoretical and experimental results. These composites were also found to display excellent percentage of heaviness with respect to other conventional materials.

Effects of Kenaf Loading on Processability and Properties of Linear Low-Density Polyethylene/Poly (Vinyl Alcohol/Kenaf Composites

Directory of Open Access Journals (Sweden)

Ai Ling Pang

2015-09-01

Full Text Available This study was conducted to evaluate the possibility of utilizing kenaf (KNF in LLDPE/PVOH to develop a new thermoplastic composite. The effect of KNF loading on the processability and mechanical, thermal and water absorption properties of linear low-density polyethylene/poly (vinyl alcohol/kenaf (LLDPE/PVOH/KNF composites were investigated. Composites with different KNF loadings (0, 10, 20, 30, and 40 phr were prepared using a Thermo Haake Polydrive internal mixer at a temperature of 150 °C and rotor speed of 50 rpm for 10 min. The results indicate that the stabilization torque, tensile modulus, water uptake, and thermal stability increased, while tensile strength and elongation at break decreased with increasing filler loading. The tensile fractured surfaces observed by scanning electron microscopy (SEM supported the deterioration in tensile properties of the LLDPE/PVOH/KNF composites with increasing KNF loading.

Polyethylene/boron-containing composites for radiation shielding

Energy Technology Data Exchange (ETDEWEB)

Shin, Ji Wook [Center for Materials Architecturing, Institute for Multi-Disciplinary Convergence of Materials, Korea Institute of Science and Technology (KIST), Seoul 136-791 (Korea, Republic of); Department of Chemical and Biological Engineering, Korea University, Seoul 136-701 (Korea, Republic of); Lee, Jang-Woo; Yu, Seunggun; Baek, Bum Ki; Hong, Jun Pyo [Center for Materials Architecturing, Institute for Multi-Disciplinary Convergence of Materials, Korea Institute of Science and Technology (KIST), Seoul 136-791 (Korea, Republic of); Seo, Yongsok [School of Materials Science and Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Kim, Woo Nyon [Department of Chemical and Biological Engineering, Korea University, Seoul 136-701 (Korea, Republic of); Hong, Soon Man, E-mail: smhong@kist.re.kr [Center for Materials Architecturing, Institute for Multi-Disciplinary Convergence of Materials, Korea Institute of Science and Technology (KIST), Seoul 136-791 (Korea, Republic of); Nanomaterials Science and Engineering, University of Science and Technology, Daejeon 305-350 (Korea, Republic of); Koo, Chong Min, E-mail: koo@kist.re.kr [Center for Materials Architecturing, Institute for Multi-Disciplinary Convergence of Materials, Korea Institute of Science and Technology (KIST), Seoul 136-791 (Korea, Republic of); Nanomaterials Science and Engineering, University of Science and Technology, Daejeon 305-350 (Korea, Republic of)

2014-06-01

Graphical abstract: - Highlights: • HDPE/silane-treated boron nitride (mBN) composites were fabricated. • The HDPE/mBN composites revealed a strong adhesion behavior at the interface of matrix/filler. • The HDPE/mBN composites show superior radiation shielding, thermoconductive and mechanical properties to the composites containing pristine BN and B{sub 4}C fillers. - Abstract: High-density polyethylene (HDPE) composites with modified boron nitride (mBN) fillers, functionalized with an organosilane, were fabricated through conventional melt-extrusion processing techniques. The properties and performances of these composites were compared with those of the composites containing pristine BN and boron carbide (B{sub 4}C) fillers. The silane functionalization of the BN fillers strongly improved the interfacial adhesion between the polymer matrix and the filler. As a result, the HDPE/mBN composites showed a better dispersion state of the filler particles, larger tensile modulus, greater effective thermal conductivity, and better neutron shielding property compared with the HDPE/BN and HDPE/B{sub 4}C composites.

Polyethylene/boron-containing composites for radiation shielding

International Nuclear Information System (INIS)

Shin, Ji Wook; Lee, Jang-Woo; Yu, Seunggun; Baek, Bum Ki; Hong, Jun Pyo; Seo, Yongsok; Kim, Woo Nyon; Hong, Soon Man; Koo, Chong Min

2014-01-01

Graphical abstract: - Highlights: • HDPE/silane-treated boron nitride (mBN) composites were fabricated. • The HDPE/mBN composites revealed a strong adhesion behavior at the interface of matrix/filler. • The HDPE/mBN composites show superior radiation shielding, thermoconductive and mechanical properties to the composites containing pristine BN and B 4 C fillers. - Abstract: High-density polyethylene (HDPE) composites with modified boron nitride (mBN) fillers, functionalized with an organosilane, were fabricated through conventional melt-extrusion processing techniques. The properties and performances of these composites were compared with those of the composites containing pristine BN and boron carbide (B 4 C) fillers. The silane functionalization of the BN fillers strongly improved the interfacial adhesion between the polymer matrix and the filler. As a result, the HDPE/mBN composites showed a better dispersion state of the filler particles, larger tensile modulus, greater effective thermal conductivity, and better neutron shielding property compared with the HDPE/BN and HDPE/B 4 C composites

Effect of gamma irradiation on linear low density polyethylene/magnesium hydroxide/sepiolite composite

International Nuclear Information System (INIS)

Shafiq, Muhammad; Yasin, Tariq

2012-01-01

Radiation crosslinking is generally used to improve the thermo-mechanical properties of the composites. A study has been carried out to investigate the effect of gamma radiation on the thermo-mechanical properties of linear low density polyethylene containing magnesium hydroxide (MH) and sepiolite (SP) as non-halogenated flame retardant additives. The developed composites are irradiated at different doses upto maximum of 150 kGy. Infrared spectra of the irradiated composites reveal the reduction in the intensity of O-H band with increase in the absorbed doses, thus indicates a distinct structural change in MH at higher doses. The thermogravimetric analysis results of unirradiated and composites irradiated at low doses (≤75 kGy) show two steps weight loss, which is changed to single step at higher doses with lower thermal stability. The melting temperature (T m ) and crystallization temperature (T c ) of irradiated composites are lowered with irradiation whereas Vicat softening temperature (VST) is increased. The increasing trend in gel content with increase in the absorbed dose confirms the presence of crosslinked network. The mechanical properties, results show significant improvement in the modulus of irradiated composites. The results also confirm that MH gradually loses its OH functionality with irradiation. - Highlights: → We have studied the effect of γ radiation on LLDPE containing Mg(OH) 2 and sepiolite. → IR spectra of the irradiated composites show reduction in the intensity of O-H band. → Reduction in OH band show a distinct structural change in Mg(OH) 2 at higher doses. → TGA results show two steps weight loss at low doses and one step at higher doses. → These results confirm that MH gradually loses its OH functionality with irradiation.

Zinc layered hydroxide salts: intercalation and incorporation into low-density polyethylene

OpenAIRE

Jaerger,Silvia; Zimmermann,Ademir; Zawadzki,Sonia Faria; Wypych,Fernando; Amico,Sandro Campos

2014-01-01

In this study, polymer composites using low-density polyethylene (LDPE) and layered hydroxide salts (LHS) were synthesized. The following compositions of LHS were obtained Zn5(OH)8(An-)2/n.yH2O, where A was varied in order to obtain hydrophilic (A = NO3 -) or hydrophobic (A = DDS- – dodecyl sulfate or DBS- – dodecyl benzene sulfonate). Synthesis was carried out by co-precipitation in alkaline medium and drying, being followed by characterization via Fourier-transform infrared spectroscopy, th...

Comparative studies on physico-mechanical properties of composite materials of low density polyethylene and raw/calcined kaolin

Directory of Open Access Journals (Sweden)

Amit Mallik

2015-06-01

Full Text Available The paper describes the preparation of the composite materials of low density polyethylene (LDPE as the base mixed separately with raw kaolin and the same calcined at 800 °C under the same variation in weight percentage using single-screw extruder and a mixing machine operated at a temperature between 190 and 200 °C. Some of the mechanical and physical properties such as Young's modulus, elongation at break, shore hardness and water absorption were determined at different weight fractions of filler (0, 2, 7, 10 and 15%. It was found that the addition of filler increases the mechanical properties. Absorption test was done in water at different immersion times for different composites. The degree of water absorption of composite materials was found to decrease with increasing wt% of kaolin filler (0–15% according to Fick's law. Calcined kaolin produces better mechanical properties than raw kaolin.

Enhancement of the Mechanical Properties of Basalt Fiber-Wood-Plastic Composites via Maleic Anhydride Grafted High-Density Polyethylene (MAPE Addition

Directory of Open Access Journals (Sweden)

Yun Lu

2013-06-01

Full Text Available This study investigated the mechanisms, using microscopy and strength testing approaches, by which the addition of maleic anhydride grafted high-density polyethylene (MAPE enhances the mechanical properties of basalt fiber-wood-plastic composites (BF-WPCs. The maximum values of the specific tensile and flexural strengths are achieved at a MAPE content of 5%–8%. The elongation increases rapidly at first and then continues slowly. The nearly complete integration of the wood fiber with the high-density polyethylene upon MAPE addition to WPC is examined, and two models of interfacial behavior are proposed. We examined the physical significance of both interfacial models and their ability to accurately describe the effects of MAPE addition. The mechanism of formation of the Model I interface and the integrated matrix is outlined based on the chemical reactions that may occur between the various components as a result of hydrogen bond formation or based on the principle of compatibility, resulting from similar polarity. The Model I fracture occurred on the outer surface of the interfacial layer, visually demonstrating the compatibilization effect of MAPE addition.

Enhancement of the Mechanical Properties of Basalt Fiber-Wood-Plastic Composites via Maleic Anhydride Grafted High-Density Polyethylene (MAPE) Addition.

Science.gov (United States)

Chen, Jinxiang; Wang, Yong; Gu, Chenglong; Liu, Jianxun; Liu, Yufu; Li, Min; Lu, Yun

2013-06-18

This study investigated the mechanisms, using microscopy and strength testing approaches, by which the addition of maleic anhydride grafted high-density polyethylene (MAPE) enhances the mechanical properties of basalt fiber-wood-plastic composites (BF-WPCs). The maximum values of the specific tensile and flexural strengths are achieved at a MAPE content of 5%-8%. The elongation increases rapidly at first and then continues slowly. The nearly complete integration of the wood fiber with the high-density polyethylene upon MAPE addition to WPC is examined, and two models of interfacial behavior are proposed. We examined the physical significance of both interfacial models and their ability to accurately describe the effects of MAPE addition. The mechanism of formation of the Model I interface and the integrated matrix is outlined based on the chemical reactions that may occur between the various components as a result of hydrogen bond formation or based on the principle of compatibility, resulting from similar polarity. The Model I fracture occurred on the outer surface of the interfacial layer, visually demonstrating the compatibilization effect of MAPE addition.

Laboratory tests on fungal resistance of wood filled polyethylene composites

Science.gov (United States)

Craig M. Clemons; Rebecca E. Ibach

2002-01-01

A standard method for determining the durability of structural wood was modified for testing the fungal resistance of composites made from high density polyethylene filled with 50% wood flour. Moisture content, mechanical properties, and weight loss were measured over 12 weeks exposure to brown-and white-rot fungi. Mechanical properties were decreased, but irreversible...

Gamma irradiation effects in low density polyethylene

International Nuclear Information System (INIS)

Ono, Lilian S.; Scagliusi, Sandra R.; Cardoso, Elisabeth E.L.; Lugao, Ademar B.

2011-01-01

Low density polyethylene (LDPE) is obtained from ethylene gas polymerization, being one of the most commercialized polymers due to its versatility and low cost. It's a semi-crystalline polymer, usually inactive at room temperature, capable to attain temperatures within a 80 deg C - 100 deg C range, without changing its physical-chemical properties. LDPE has more resistance when compared to its equivalent High Density Polyethylene (HDPE). LDPE most common applications consist in manufacturing of laboratory materials, general containers, pipes, plastic bags, etc. Gamma radiation is used on polymers in order to modify mechanical and physical-chemical features according to utility purposes. This work aims to the study of gamma (γ) radiation interaction with low density polyethylene to evaluate changes in its physical-chemical properties. Polymer samples were exposed to 5, 10, 15, 20 and 30kGy doses, at room temperature. Samples characterization employed Thermal Analysis, Melt Flow Index, Infrared Spectroscopy and Swelling tests. (author)

Preparation of High Density Polyethylene/Waste Polyurethane Blends Compatibilized with Polyethylene-Graft-Maleic Anhydride by Radiation

Directory of Open Access Journals (Sweden)

Jong-Seok Park

2015-04-01

Full Text Available Polyurethane (PU is a very popular polymer that is used in a variety of applications due to its good mechanical, thermal, and chemical properties. However, PU recycling has received significant attention due to environmental issues. In this study, we developed a recycling method for waste PU that utilizes the radiation grafting technique. Grafting of waste PU was carried out using a radiation technique with polyethylene-graft-maleic anhydride (PE-g-MA. The PE-g-MA-grafted PU/high density polyethylene (HDPE composite was prepared by melt-blending at various concentrations (0–10 phr of PE-g-MA-grafted PU. The composites were characterized using fourier transform infrared spectroscopy (FT-IR, and their surface morphology and thermal/mechanical properties are reported. For 1 phr PU, the PU could be easily introduced to the HDPE during the melt processing in the blender after the radiation-induced grafting of PU with PE-g-MA. PE-g-MA was easily reacted with PU according to the increasing radiation dose and was located at the interface between the PU and the HDPE during the melt processing in the blender, which improved the interfacial interactions and the mechanical properties of the resultant composites. However, the elongation at break for a PU content >2 phr was drastically decreased.

Effect of cooling rate on the properties of high density polyethylene/multi-walled carbon nanotube composites

Energy Technology Data Exchange (ETDEWEB)

Xiang, Dong; Harkin-Jones, Eileen [School of Mechanical and Aerospace Engineering, Queen’s University Belfast, BT9 5AH (United Kingdom); Linton, David [School of Electronics, Electrical Engineering and Computer Science, Queen’s University Belfast, BT9 5AH (United Kingdom)

2015-05-22

High density polyethylene (HDPE)/multi-walled carbon nanotube (MWCNT) nanocomposites were prepared by melt mixing using twin-screw extrusion. The extruded pellets were compression moulded at 200°C for 5min followed by cooling at different cooling rates (20°C/min and 300°C/min respectively) to produce sheets for characterization. Scanning electron microscopy (SEM) shows that the MWCNTs are uniformly dispersed in the HDPE. At 4 wt% addition of MWCNTs composite modulus increased by over 110% compared with the unfilled HDPE (regardless of the cooling rate). The yield strength of both unfilled and filled HDPE decreased after rapid cooling by about 10% due to a lower crystallinity and imperfect crystallites. The electrical percolation threshold of composites, irrespective of the cooling rate, is between a MWCNT concentration of 1∼2 wt%. Interestingly, the electrical resistivity of the rapidly cooled composite with 2 wt% MWCNTs is lower than that of the slowly cooled composites with the same MWCNT loading. This may be due to the lower crystallinity and smaller crystallites facilitating the formation of conductive pathways. This result may have significant implications for both process control and the tailoring of electrical conductivity in the manufacture of conductive HDPE/MWCNT nanocomposites.

Effect of cooling rate on the properties of high density polyethylene/multi-walled carbon nanotube composites

International Nuclear Information System (INIS)

Xiang, Dong; Harkin-Jones, Eileen; Linton, David

2015-01-01

High density polyethylene (HDPE)/multi-walled carbon nanotube (MWCNT) nanocomposites were prepared by melt mixing using twin-screw extrusion. The extruded pellets were compression moulded at 200°C for 5min followed by cooling at different cooling rates (20°C/min and 300°C/min respectively) to produce sheets for characterization. Scanning electron microscopy (SEM) shows that the MWCNTs are uniformly dispersed in the HDPE. At 4 wt% addition of MWCNTs composite modulus increased by over 110% compared with the unfilled HDPE (regardless of the cooling rate). The yield strength of both unfilled and filled HDPE decreased after rapid cooling by about 10% due to a lower crystallinity and imperfect crystallites. The electrical percolation threshold of composites, irrespective of the cooling rate, is between a MWCNT concentration of 1∼2 wt%. Interestingly, the electrical resistivity of the rapidly cooled composite with 2 wt% MWCNTs is lower than that of the slowly cooled composites with the same MWCNT loading. This may be due to the lower crystallinity and smaller crystallites facilitating the formation of conductive pathways. This result may have significant implications for both process control and the tailoring of electrical conductivity in the manufacture of conductive HDPE/MWCNT nanocomposites

Enhancement of mechanical strength of TiO2/high-density polyethylene composites for bone repair with silane-coupling treatment

International Nuclear Information System (INIS)

Hashimoto, Masami; Takadama, Hiroaki; Mizuno, Mineo; Kokubo, Tadashi

2006-01-01

Mechanical properties of composites made up of high-density polyethylene (HDPE) and silanated TiO 2 particles for use as a bone-repairing material were investigated in comparison with those of the composites of HDPE with unsilanized TiO 2 particles. The interfacial morphology and interaction between silanated TiO 2 and HDPE were analyzed by means of Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). The absorption in spectral bands related to the carboxyl bond in the silane-coupling agent, the vinyl group in the HDPE, and the formation of the ether bond was studied in order to assess the influence of the silane-coupling agent. The SEM micrograph showed that the 'bridging effect' between HDPE and TiO 2 was brought about by the silane-coupling agent. The use of the silane-coupling agent and the increase of the hot-pressing pressure for shaping the composites facilitated the penetration of polymer into cavities between individual TiO 2 particles, which increased the density of the composite. Therefore, mechanical properties such as bending yield strength and Young's modulus increased from 49 MPa and 7.5 GPa to 65 MPa and 10 GPa, respectively, after the silane-coupling treatment and increase in the hot-pressing pressure

Polymeric compositions incorporating polyethylene glycol as a phase change material

Science.gov (United States)

Salyer, Ival O.; Griffen, Charles W.

1989-01-01

A polymeric composition comprising a polymeric material and polyethylene glycol or end-capped polyethylene glycol as a phase change material, said polyethylene glycol and said end-capped polyethylene glycol having a molecular weight greater than about 400 and a heat of fusion greater than about 30 cal/g; the composition is useful in making molded and/or coated materials such as flooring, tiles, wall panels and the like; paints containing polyethylene glycols or end-capped polyethylene glycols are also disclosed.

Effect of carrageenan on properties of biodegradable thermoplastic cassava starch/low-density polyethylene composites reinforced by cotton fibers

International Nuclear Information System (INIS)

Prachayawarakorn, Jutarat; Pomdage, Wanida

2014-01-01

Highlights: • We prepared the TPCS/LDPE composites modified by carrageenan and/or cotton fibers. • The IR O–H stretching peak of the modified composites shifts to lower wavenumber. • Stress and Young’s modulus of the modified composites increase significantly. • The modified composites degrade faster than the non-modified composite. - Abstract: Applications of biodegradable thermoplastic starch (TPS) have been restricted due to its poor mechanical properties, limited processability and high water uptake. In order to improve properties and processability, thermoplastic cassava starch (TPCS) was compounded with low-density polyethylene (LDPE). The TPCS/LDPE blend was, then, modified by a natural gelling agent, i.e. carrageenan and natural fibers, i.e. cotton fibers. All composites were compounded and processed using an internal mixer and an injection molding machine, respectively. It was found that stress at maximum load and Young’s modulus of the TPCS/LDPE composites significantly increased by the addition of the carrageenan and/or the cotton fibers. The highest mechanical properties were obtained from the TPCS/LDPE composites modified by both the carrageenan and the cotton fibers. Percentage water absorption of all of the TPCS/LDPE composites was found to be similar. All modified composites were also degraded easier than the non-modified one. Furthermore, all the composites were analyzed using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Scanning electron microscopy (SEM)

Electrical resistivity of carbon black-filled high-density polyethylene (HDPE) composite containing radiation crosslinked HDPE particles

International Nuclear Information System (INIS)

Lee, M.-G.; Nho, Y.C.

2001-01-01

The room-temperature volume resistivity of high-density polyethylene (HDPE)-carbon black (CB) blends containing previously radiation crosslinked HDPE powder was studied. The results showed that the room-temperature volume resistivity decreases with increasing concentration of crosslinked HDPE powder. It is considered that the crosslinked HDPE particles act as a filler that increases the CB volume fraction in the HDPE matrix. The results of an optical microscope observation indicated that the crosslinked polymer particles are dispersed in the HDPE/CB composite. This effect of the crosslinked particles is attributed to the fact that the crosslinked mesh size of the HDPE particles is so small that the CB particles cannot go inside them. The effect of 60 Co γ-ray and electron beam (EB) irradiation on the positive temperature coefficient, negative temperature coefficient and electrical resistivity behavior of the blends were studied

Use of gamma radiation for the obtainment of a polyethylene-sugarcane bagasse composite

International Nuclear Information System (INIS)

Romero, Guillermo R.; Gonzalez, Maria E.

2003-01-01

The preparation and some properties of a composite obtained by reactive extrusion of a medium density polyethylene and sugarcane bagasse fiber previously treated with gamma radiation in the presence of a reactive additive is presented. The proportion of fiber to polyethylene was approximately 50 % w/w. According to the electronic microscopic observation the fibers had a homogeneous distribution and were oriented in a longitudinal sense in the material. The material resulted suitable for processing by extrusion, injection or compression molding. Its water absorption capacity was similar to polyethylene and its flexion modulus was higher by about 60 %. Penetration measurements with a 1-mm penetrometers gave values intermediate between that of pine and polypropylene. (author)

Mechanical properties of low-density polyethylene filled by graphite nanoplatelets

DEFF Research Database (Denmark)

Carotenuto, G.; De Nicola, S.; Palomba, M.

2012-01-01

The mechanical properties of GNP/LDPE nanocomposites (graphite nanoplatelets/low density polyethylene) have been investigated, in order to establish the effect of nanoscale reinforcement within the polymer matrix. Results show that the presence of the filler does not involve a change...... in the microscopic structure of the polymer. However, on a macroscopic scale, GNPs limit the mobility of the polymer chains, resulting in an increase in stiffness for the final composite. Orientation of GNPs within the LDPE matrix is also an important issue that affects mechanical properties and it has been...

An Facile High-Density Polyethylene - Exfoliated Graphite - Aluminium Hydroxide Composite: Manufacture, Morphology, Structure, Antistatic and Fireproof Properties

Directory of Open Access Journals (Sweden)

Jihui LI

2014-09-01

Full Text Available Graphite intercalation compounds (GIC and exfoliated graphite (EG as raw materials were prepared with flake graphite, concentrated sulphuric acid (H2SO4, potassium bichromate (K2Cr2O7 and peracetic acid (CH3CO3H and characterized. Then, high-density polyethylene-exfoliated graphite (HDPE-EG composites were fabricated with HDPE and EG via in situ synthesis technique in the different mass ratio, and their resistivity values (ohms/sq were measured. Based on the resistivity values, it was discovered that HDPE-EG composite with the antistatic property could be fabricated while the mass ratio was 5.00 : 0.30. Last, HDPE-EG-aluminium hydroxide (HDPE-EG-Al(OH3 composites were manufactured with HDPE, GIC and Al(OH3 via the in situ synthesis-thermal expansion technique, and their resistivity values and limiting oxygen index (LOI values were measured. Based on the resistivity values and LOI values, it was discovered that HDPE-EG-Al(OH3 composite with the antistatic and fireproof property could be manufactured while HDPE, GICs and Al(OH3 of mass ratio was 5.00 : 0.30 : 1.00. Otherwise, the petal-like morphology and structure of HDPE-EG-Al(OH3 composite were characterized, which consisted of EG, HDPE and Al(OH3. DOI: http://dx.doi.org/10.5755/j01.ms.20.3.4275

Biological resistance of polyethylene composites made with chemically modified fiber or flour

Science.gov (United States)

Rebecca E. Ibach; Craig M. Clemons

2002-01-01

The role of moisture in the biological decay of wood-plastic composites was investigated. Southern pine wood fiber and ponderosa pine wood flour were chemically modified using either acetic anhydride (AA), butylene oxide (BO), or propylene oxide (PO). A 50:50 mixture of high density polyethylene and either chemically modified fiber or flour, or untreated fiber or flour...

Tensile properties and water absorption assessment of linear low-Density Polyethylene/Poly (Vinyl Alcohol)/Kenaf composites: effect of eco-friendly coupling agent

Science.gov (United States)

Pang, A. L.; Ismail, H.; Abu Bakar, A.

2018-02-01

Linear low-density polyethylene (LLDPE)/poly (vinyl alcohol) (PVOH) filled with untreated kenaf (UT-KNF) and eco-friendly coupling agent (ECA)-treated kenaf (ECAT-KNF) were prepared using ThermoHaake internal mixer, respectively. Filler loadings of UT-KNF and ECAT-KNF used in this study are 10 and 40 parts per hundred parts of resin (phr). The effect of ECA on tensile properties and water absorption of LLDPE/PVOH/KNF composites were investigated. Field emission scanning electron microscopy (FESEM) analysis was applied to visualize filler-matrix adhesion. The results indicate LLDPE/PVOH/ECAT-KNF composites possess higher tensile strength and tensile modulus, but lower elongation at break compared to LLDPE/PVOH/UT-KNF composites. The morphological studies of tensile fractured surfaces using FESEM support the increment in tensile properties of LLDPE/PVOH/ECAT-KNF composites. Nevertheless, LLDPE/PVOH/UT-KNF composites reveal higher water absorption compared to LLDPE/PVOH/ECAT-KNF composites.

Dielectric properties of nanosilica/low-density polyethylene composites: The surface chemistry of nanoparticles and deep traps induced by nanoparticles

Directory of Open Access Journals (Sweden)

S. Ju

2014-09-01

Full Text Available Four kinds of nanosilica particles with different surface modification were employed to fabricate low-density polyethylene (LDPE composites using melt mixing and hot molding methods. The surface chemistry of modified nanosilica was analyzed by X-ray photoelectron spectroscopy. All silica nanoparticles were found to suppress the space charge injection and accumulation, increase the volume resistivity, decrease the permittivity and dielectric loss factor at low frequencies, and decrease the dielectric breakdown strength of the LDPE polymers. The modified nanoparticles, in general, showed better dielectric properties than the unmodified ones. It was found that the carrier mobility, calculated from J–V curves using the Mott-Gurney equation, was much lower for the nanocomposites than for the neat LDPE.

Properties Evaluation of High Density Polyethylene Composite Filled with Bagasse after Accelerated Weathered

Directory of Open Access Journals (Sweden)

Peyvand Darabi

2013-06-01

Full Text Available Wood plastic composites (WPCs are produced from a mixture of wood (in different sizes and resin (thermoset or thermoplastic. This product has many applications as structural and non-structural materials and since its emerge in market its use received an increasing trend. Adding wood flour to polymer not only improves its mechanical properties compared to net polymer, but also leads to products with moldability characteristics. With increasing demand of WPCs and reduction in forest harvest according to new protecting law of forestry, and lack of raw materials for producers, other lignocelluloses materials replace wood flour. Agricultural by-products such as hemp, coir, rice husk and bagasse (residual from sugar cane extraction are the examples that can be used in WPCs. As the outdoor application of Wood Plastic Composites (WPCs becomes more widespread, the resistance of its products against weathering, particularly ultraviolet (UV light becomes more concerned. When WPCs are exposed to outdoor, ultraviolet (UV light, rain, snow and atmospheric pollution, they will be degraded which is marked by color fade and loss in mechanical properties. Nowadays many manufactures of WPCs use bagasse as a raw material. Their production in different color and shapes are used as arbors and pergolas and also as decorative applications for outdoor uses. However, so far there has been no research done on the effects of weathering on composites made from bagasse. In present study, composites from bagasse and high density polyethylene, with and without pigments in master batch, have been made through extrusion. Then samples were exposed to accelerated weathering for 1440h. After this period of time samples were removed and their chemical, mechanical and surface qualities were studied. The results have shown that using bagasse as filler can relatively reduce the discoloration of weathered samples. Moreover, adding pigments to WPCs can increase colorstability, while it

Effect of admixed high-density polyethylene (HDPE) spheres on contraction stress and properties of experimental composites.

Science.gov (United States)

Ferracane, J L; Ferracane, L L; Braga, R R

2003-07-15

Additives that provide stress relief may be incorporated into dental composites to reduce contraction stress (CS). This study attempted to test the hypothesis that conventional fillers could be replaced by high-density polyethylene (HDPE) spheres in hybrid and nanofill composites to reduce CS, but with minimal effect on mechanical properties. Nanofill and hybrid composites were made from a Bis-GMA/TEGDMA resin having either all silica nanofiller or 75 wt.% strontium glass + 5 wt.% silica and replacing some of the nanofiller or the glass with 0%, 5% (hybrid only), 10% or 20 wt.% HDPE. The surface of the HDPE was either left untreated or had a reactive gas surface treatment (RGST). Contraction stress (CS) was monitored for 10 min in a tensilometer (n = 5) after light curing for 60 s at 390 mW/cm(2). Other specimens (n = 5) were light cured 40 s from two sides in a light-curing unit and aged 1 d in water before testing fracture toughness (K(Ic)), flexure strength (FS), and modulus (E). Results were analyzed by ANOVA with Tukey's multiple comparison test at p HDPE except for FS-10% HDPE hybrid (RGST higher). An increased level of HDPE reduced contraction stress for both types of composites. Flexure strength, modulus (hybrid only), and fracture toughness were also reduced as the concentration of HDPE increased. SEM showed evidence for HDPE debonding and plastic deformation during fracture of the hybrid composites. In conclusion, the addition of HDPE spheres reduces contraction stress in composites, either through stress relief or a reduction in elastic modulus. Copyright 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 66B: 318-323, 2003

Effect of Bagasse Chemical Pulping and Coupling Agent on the Physical - Mechanical Properties of Composites Based on Bagasse pulp/Low density polyethylene

Directory of Open Access Journals (Sweden)

maryam allahdadi

2016-12-01

Full Text Available In this research, effect of reinforcing bagasse pulp and raw bagasse fibers and applying coupling agent MAPE (Maleic Anhydride Polyethylene on physical-mechanical properties of low density polyethylene (LDPE composites were studided. Fresh bagasse were collected from an experimental field in Khuzestan and after investigating anatomy and chemical properties of Different pulp fibers including monoethanolamine (MEA bagasse pulp, alkaline sulfite-anthraquinone (AS bagasse pulp, bleached soda (BS bagasse pulp, unbleached soda (UNS bagasse pulp and raw bagasse fibers (B were prepared. Then, composites with 30wt.% fiber content were manufactured by twin-screw extrusion followed by compression molding processing. The mechanical and physical properties of these composites were analyzed and compared. Results revealed that the chemical pulping dissolved a fraction of lignin and hemicelluloses so that the linkage potential and aspect ratio of bagasse fibers was improved and consequently, as compared with the raw bagasse fibers, bagasse pulp fibers have better reinforcing capability. The best overall properties were achieved with MEA and AS/AQ fibers. Addition of 5% (wt/wt of coupling agent MAPE resulted in a significant enhancement in the tensile strength, tensile modulus and impact strength in line with the improvement of the fiber-matrix interfacial adhesion making more effective the transfer of stress from the matrix to the rigid reinforcement.

Development of nanocomposites employing high-density polyethylene and organo clay

International Nuclear Information System (INIS)

Lessa, Tathiane C. Rodrigues F.; Tavares, Maria Ines B.; Pita, Vitor J.R.R.

2009-01-01

The purpose of this study was to prepare nanocomposites of high-density polyethylene and montmorillonite organoclay by polymer melt intercalation, employing different processing parameters. Effective clay incorporation into polyethylene matrix was observed. The nanocomposites were structurally characterized. Intercalated nanocomposites were obtained from different process parameters, employing polyethylene resin and montmorillonite organoclays. The XRD results and other analysis showed that the processing parameters affect the organoclay delamination. The polyethylene nanocomposite presented the better performance using twin screw extruder, at 90 rpm. The purpose of characterization of polyethylene/organoclay nanocomposite by low-field NMR showed that this technique was important to understand changes in the molecular mobility of polyethylene when organoclay was incorporated. (author)

Static viscoelasticity of biomass polyethylene composites

Directory of Open Access Journals (Sweden)

Keyan Yang

Full Text Available The biomass polyethylene composites filled with poplar wood flour, rice husk, cotton stalk or corn stalk were prepared by extrusion molding. The static viscoelasticity of composites was investigated by the dynamic thermal mechanical analyzer (DMA. Through the stress-strain scanning, it is found that the linear viscoelasticity interval of composites gradually decreases as the temperature rises, and the critical stress and strain values are 0.8 MPa and 0.03% respectively. The experiment shows that as the temperature rises, the creep compliance of biomass polyethylene composites is increased; under the constant temperature, the creep compliance decreases with the increase of content of biomass and calcium carbonate. The biomass and calcium carbonate used to prepare composites as filler can improve damping vibration attenuation and reduce stress deformation of composites. The stress relaxation modulus of composites is reduced and the relaxation rate increases at the higher temperature. The biomass and calcium carbonate used to prepare composites as filler not only can reduce costs, but also can increase stress relaxation modulus and improve the size thermostability of composites. The corn stalk is a good kind of biomass raw material for composites since it can improve the creep resistance property and the stress relaxation resistance property of composites more effectively than other three kinds of biomass (poplar wood flour, rice husk and cotton stalk. Keywords: Biomass, Composites, Calcium carbonate, Static viscoelasticity, Creep, Stress relaxation

Interfacial thermal resistance between high-density polyethylene (HDPE) and sapphire

International Nuclear Information System (INIS)

Zheng Kun; Ma Yong-Mei; Wang Fo-Song; Zhu Jie; Tang Da-Wei

2014-01-01

To improve the thermal conductivity of polymeric composites, the numerous interfacial thermal resistance (ITR) inside is usually considered as a bottle neck, but the direct measurement of the ITR is hardly reported. In this paper, a sandwich structure which consists of transducer/high density polyethylene (HDPE)/sapphire is prepared to study the interface characteristics. Then, the ITRs between HDPE and sapphire of two samples with different HDPE thickness values are measured by time-domain thermoreflectance (TDTR) method and the results are ∼ 2 × 10 −7 m 2 ·K·W −1 . Furthermore, a model is used to evaluate the importance of ITR for the thermal conductivity of composites. The model's analysis indicates that reducing the ITR is an effective way of improving the thermal conductivity of composites. These results will provide valuable guidance for the design and manufacture of polymer-based thermally conductive materials. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Modification of low density polyethylene, isostatic polypropylene and their blends by gamma radiation

International Nuclear Information System (INIS)

Santos Rosa, D. dos

1991-01-01

The effects of the gamma radiation (of a 60 Co source), over low density polyethylene, isostatic polypropylene and their blends of low density polyethylene / polypropylene were studied. The structures modifications were attended by infrared spectrometry (IV), differential scanning calorimeter (DSC), strain-strain measurement, density measurement and scanning electron microscope (SEM). (author)

On the mechanism of charge transport in low density polyethylene

Science.gov (United States)

Upadhyay, Avnish K.; Reddy, C. C.

2017-08-01

Polyethylene based polymeric insulators, are being increasingly used in the power industry for their inherent advantages over conventional insulation materials. Specifically, modern power cables are almost made with these materials, replacing the mass-impregnated oil-paper cable technology. However, for ultra-high dc voltage applications, the use of these polymeric cables is hindered by ununderstood charge transport and accumulation. The conventional conduction mechanisms (Pool-Frenkel, Schottky, etc.) fail to track high-field charge transport in low density polyethylene, which is semi-crystalline in nature. Until now, attention was devoted mainly to the amorphous region of the material. In this paper, authors propose a novel mechanism for conduction in low density polyethylene, which could successfully track experimental results. As an implication, a novel, substantial relationship is established for electrical conductivity that could be effectively used for understanding conduction and breakdown in polyethylene, which is vital for successful development of ultra-high voltage dc cables.

Slow crack growth in post-consumer recycled high-density polyethylene

OpenAIRE

Sciammarella, Cesar A.; Yang, Y.

2015-01-01

An experimental study of slow crack growth behavior of post-consumer recycled high-density polyethylene blended with virgin high-density polyethylene copolymer has been done. The study has been performed under constant load and in baths of distilled water at 40, 60, 80°C. The specimen used is notched with side grooves. The test results of crack growth have been analyzed using linear fracture mechanics and the rate process theory. The results show that the resistance to crack growth increases ...

Interfacial Properties of Bamboo Fiber-Reinforced High-Density Polyethylene Composites by Different Methods for Adding Nano Calcium Carbonate

Directory of Open Access Journals (Sweden)

Cuicui Wang

2017-11-01

Full Text Available The focus of this study was to observe the effect of nano calcium carbonate (CaCO3 modification methods on bamboo fiber (BF used in BF-reinforced high-density polyethylene (HDPE composites manufactured by extrusion molding. Two methods were used to introduce the nano CaCO3 into the BF for modification; the first was blending modification (BM and the second was impregnation modification (IM. In order to determine the effects of the modification methods, the water absorption, surface free energy and interfacial properties of the unmodified composites were compared to those of the composites made from the two modification methods. The results revealed that the percentage increase in the weight of the composite treated by nano CaCO3 decreased and that of the IMBF/HDPE composite was the lowest over the seven months of time. The results obtained by the acid-base model according to the Lewis and Owens-Wendt- Rabel-Kaelble (OWRK equations indicated that the surface energy of the composites was between 40 and 50 mJ/m2. When compared to the control sample, the maximum storage modulus (E′max of the BMBF/HDPE and IMBF/HDPE composites increased 1.43- and 1.53-fold, respectively. The values of the phase-to-phase interaction parameter B and the k value of the modified composites were higher than those of the unmodified composites, while the apparent activation energy Ea and interface parameter A were lower in the modified composites. It can be concluded that nano CaCO3 had an effect on the interfacial properties of BF-reinforced HDPE composites, and the interface bonding between IMBF and HDPE was greatest among the composites.

Study of mechanical and morphological properties of bio-based polyethylene (HDPE) and sponge-gourds (Luffa-cylindrica) agroresidue composites

Science.gov (United States)

Escocio, Viviane A.; Visconte, Leila L. Y.; Cavalcante, Andre de P.; Furtado, Ana Maria S.; Pacheco, Elen B. A. V.

2015-05-01

Brazil has a remarkable position in the use of renewable energy. The potential of natural resources in Brazil has motivated the use of these renewable resources to make technologies more sustainable. From the large variety of commercially available High Density Polyethylene (HDPE) from different sources, two were chosen for investigation: one produced from sugarcane ethanol, and the other one, a conventional polyethylene, produced from fossil resources. In the preparation of the composites, sponge-gourds also called Luffa cylindrica were selectec. The main application of this product is as bath sponge, whose production generates scraps that are generally burnt. In this work, the composites were prepared by blending the sponge scrap at different proportions (10, 20, 30 and 40% wt/wt) with high density polyethylene (HDPE) from renewable source by extrusion. The melt flow index analysis of the composites was determined and specimens were obtained by injection molding for the assessment of mechanical properties such as tensile (elasticity modulus), flexural and Izod impact strengths. The microstructure of the impact fractured surface of the specimen also was determined. The results showed that the addition of sponge scrap affects positively all the properties studied as compared to HDPE. The results of tensile strength, elasticity modulus and flexural strength were similar to those observed in the literature for composites of HDPE from fossil source. The microstructure corroborates the results of mechanical properties. It was shown that the sponge scrap has potential to be applied as cellulosic filler for renewable polyethylene, providing a totally renewable material with good mechanical properties.

Mechanical and Thermal Properties of R-High Density Polyethylene Composites Reinforced with Wheat Straw Particleboard Dust and Basalt Fiber

Directory of Open Access Journals (Sweden)

Min Yu

2018-01-01

Full Text Available The effect of individual and combined particleboard dust (PB dust and basalt fibers (BFs on mechanical and thermal expansion performance of the filled virgin and recycled high density polyethylene (HDPE composites was studied. It was shown that the use of PB dust had a positive effect on improving mechanical properties and on reducing linear coefficient of thermal expansion (LCTE values of filled composites, because the adhesive of the particle board held the wheat straw fibers into bundles, which made PB dust have a certain aspect ratio and high strength. Compared with the commonly used commercial WPC products, the flexural strength of PB dust/VHDPE, PB dust/RHDPE, and PB dust/VHDPE/RHDEPE at 40 wt% loading level increased by 79.9%, 41.5%, and 53.9%, respectively. When 40 wt% PB dust was added, the crystallization degree of the composites based on three matrixes decreased to 72.5%, 45.7%, and 64.1%, respectively. The use of PB dust can help lower the composite costs and increase its recyclability. Mechanical properties and LCTE values of composites with combined BF and PB dust fillers varied with PB dust and BF ratio at a given total filler loading level. As the BF portion of the PB dust/BF fillers increased, the LCTE values decreased markedly, which was suggested to be able to achieve a desirable dimensional stability for composites. The process provides a useful route to further recycling of agricultural wastes.

Mechanical properties of chemically modified Sansevieria trifasciata/natural rubber/high density polyethylene (STF/NR/HDPE) composites: Effect of silane coupling agent

Science.gov (United States)

Zakaria, Nurzam Ezdiani; Baharum, Azizah; Ahmad, Ishak

2018-04-01

The main objective of this research is to study the effects of chemical modification on the mechanical properties of treated Sansevieria trifasciata fiber/natural rubber/high density polyethylene (TSTF/NR/HDPE) composites. Processing of STF/NR/HDPE composites was done by using an internal mixer. The processing parameters used were 135°C for temperature and a mixing rotor speed of 55 rpm for 15 minutes. Filler loading was varied from 10% to 40% of STF and the fiber size used was 125 µm. The composite blends obtained then were pressed with a hot press machine to get test samples of 1 mm and 3 mm of thickness. Samples were evaluated via tensile tests, Izod impact test and scanning electron microscopy (SEM). Results showed that tensile strength and strain value decreased while tensile modulus increased when filler loading increased. Impact strength increased when filler loading increased and began to decrease after 10% of filler amount for treated composites. For untreated composites, impact strength began to decrease after 20% of filler loading. Chemical modification by using silane coupling agent has improved certain mechanical properties of the composites such as tensile strength, strain value and tensile modulus. Adding more amount of filler will also increase the viscosity and the stiffness of the materials.

Hull Fiber From DDGS and Corn Grain as Alternative Fillers in Polymer Composites with High Density Polyethylene

Science.gov (United States)

Pandey, Pankaj

The steady increase in corn based ethanol production has resulted in a dramatic rise in the supply of its co-product known as distillers' dried grain with solubles (DDGS). Currently, the main outlet for DDGS is the animal feed industry, but the presence of fibers makes them indigestible by non-ruminants such as swine and poultry. Separation of fiber from DDGS would increase the nutritional value of DDGS with higher protein and fat contents and reduced fiber content. The fiber from DDGS can be separated through a physical separation process known as elusieve. The DDGS fiber has the potential to be used as a fiber filler in thermoplastic composites. This research project evaluates DDGS fiber as a filler in thermoplastic composites. The fibers from corn hull and DDGS have been used as fillers at 30% and 50% fiber loading in high density polyethylene (HDPE) composites and compared against a standard oak fiber filler composites at a lab scale. DDGS and corn fiber composites showed comparable mechanical properties as the oak wood fiber HDPE composites. Further evaluation was completed on the performance of composite samples at commercial scale with six combinations of oak fiber, corn hull fiber and DDGS fiber with fiber loading maintained at 50%, and then samples were exposed to UV accelerated weathering for 2000 h. The UV weathering decreased the mechanical properties of all the exposed samples compared to the unexposed samples. Also, UV weathering resulted in a severe chain scission of the HDPE polymer, increasing their crystallinity. The performance of mercerized or sodium hydroxide (NaOH) treated DDGS fiber as filler was investigated by characterizing the effects of treated and untreated DDGS fibers on physical, mechanical, and thermal properties of HDPE composites. The NaOH treated DDGS fiber at 25% loading showed consistent improvement in flexural and tensile modulus of elasticities of the composites compared to the neat HDPE.

Modeling of branching density and branching distribution in low-density polyethylene polymerization

NARCIS (Netherlands)

Kim, D.M.; Iedema, P.D.

2008-01-01

Low-density polyethylene (ldPE) is a general purpose polymer with various applications. By this reason, many publications can be found on the ldPE polymerization modeling. However, scission reaction and branching distribution are only recently considered in the modeling studies due to difficulties

The effects of particle size and content on the thermal conductivity and mechanical properties of Al2O3/high density polyethylene (HDPE composites

Directory of Open Access Journals (Sweden)

2011-07-01

Full Text Available The influences of filler size and content on the properties (thermal conductivity, impact strength and tensile strength of Al2O3/high density polyethylene (HDPE composites are studied. Thermal conductivity and tensile strength of the composites increase with the decrease of particle size. The dependence of impact strength on the particle size is more complicated. The SEM micrographs of the fracture surface show that Al2O3 with small particle size is generally more efficient for the enhancement of the impact strength, while the 100 nm particles prone to aggregation due to their high surface energy deteriorate the impact strength. Composite filled with Al2O3 of 0.5 µm at content of 25 vol% show the best synthetic properties. It is suggested that the addition of nano-Al2O3 to HDPE would lead to good performance once suitably dispersed.

Optimization of High Temperature and Pressurized Steam Modified Wood Fibers for High-Density Polyethylene Matrix Composites Using the Orthogonal Design Method

Directory of Open Access Journals (Sweden)

Xun Gao

2016-10-01

Full Text Available The orthogonal design method was used to determine the optimum conditions for modifying poplar fibers through a high temperature and pressurized steam treatment for the subsequent preparation of wood fiber/high-density polyethylene (HDPE composites. The extreme difference, variance, and significance analyses were performed to reveal the effect of the modification parameters on the mechanical properties of the prepared composites, and they yielded consistent results. The main findings indicated that the modification temperature most strongly affected the mechanical properties of the prepared composites, followed by the steam pressure. A temperature of 170 °C, a steam pressure of 0.8 MPa, and a processing time of 20 min were determined as the optimum parameters for fiber modification. Compared to the composites prepared from untreated fibers, the tensile, flexural, and impact strength of the composites prepared from modified fibers increased by 20.17%, 18.5%, and 19.3%, respectively. The effect on the properties of the composites was also investigated by scanning electron microscopy and dynamic mechanical analysis. When the temperature, steam pressure, and processing time reached the highest values, the composites exhibited the best mechanical properties, which were also well in agreement with the results of the extreme difference, variance, and significance analyses. Moreover, the crystallinity and thermal stability of the fibers and the storage modulus of the prepared composites improved; however, the hollocellulose content and the pH of the wood fibers decreased.

Mechanical behavior of recycled polyethylene/piassava fiber composites

Energy Technology Data Exchange (ETDEWEB)

Elzubair, Amal, E-mail: amal@metalmat.ufrj.br [Universidade Federal de Rio de Janeiro, Departamento de Engenharia Metalurgica e de Materiais, Ilha do Fundao, Bloco F, 21941-972 Rio de Janeiro, RJ (Brazil); Praca General Tiburcio, 80, Urca, 22290-270 Rio de Janeiro, RJ (Brazil); Miguez Suarez, Joao Carlos, E-mail: jmiguez@ime.eb.br [Instituto Militar de Engenharia, Secao de Engenharia Mecanica e de Materiais, Praca General Tiburcio, 80, Urca, 22290-270, Rio de Janeiro, RJ (Brazil); Praca General Tiburcio, 80, Urca, 22290-270 Rio de Janeiro, RJ (Brazil)

2012-11-15

The use of natural fibers for reinforcement of thermoplastics (which are found in domestic waste) is desirable since it is based on abundant and renewable resources and can be ecologically correct. Leopoldinia piassaba Wallace (commonly known as piassava), a palm tree native of Amazon-Brazil, is cheap, easily found in Brazilian markets and the main component of home appliances and decorative goods. The subject of the present work is a study of mechanical properties of composites of recycled high density polyethylene (HDPE-r) reinforced with untreated, and treated (silane and NaOH) piassava fibers, in proportions varying from 0% to 20% and injection molded under fixed processing conditions. The influence of increasing amounts of piassava fibers and of surface treatment on the mechanical behavior of the composites was investigated by thermogravimetric analysis (TGA), mechanical testing (tensile and flexure) and scanning electron microscopy (SEM). The topography of the fractured surfaces of tested tensile specimens of unfilled and filled recycled HDPE was also observed by SEM and correlated with the mechanical behavior. As the fiber content increases, the composites show a gradual change in the mechanical properties and in the fracture mechanisms. Composites with 15% and 20% of piassava fibers were found to exhibit the best mechanical performance.

Effect of wood filler treatment and EBAGMA compatibilizer on morphology and mechanical properties of low density polyethylene/olive husk flour composites

Directory of Open Access Journals (Sweden)

2007-07-01

Full Text Available This paper deals with plastic-wood composites based on low density polyethylene (LDPE and olive husk flour (OHF. The problem of incompatibility between the hydrophilic wood filler and the LDPE hydrophobic matrix was treated by two methods: a chemical modification of the olive husk flour with maleic anhydride to esterify the free hydroxyl groups of the wood components and the use of a compatibilizer agent, i.e. an ethylene-butyl acrylate-glycidyl methacrylate (EBAGMA terpolymer. The changes in the structure, the morphology, and the properties resulting from these treatments were followed by various techniques, especially FTIR spectroscopy, scanning electron microscopy (SEM, tensile measurements and water absorption. The experimental results indicated that both methods, i.e. the chemical treatment of the olive husk flour with maleic anhydride and the inclusion of EBAGMA terpolymer, improved the interactions between the two composite components and promoted better dispersion of the filler in the matrix. Moreover, ultimate tensile properties were also increased. However, the use of EBAGMA terpolymer as compatibilizer produced better enhancement of the properties of LDPE/OHF composites compared to those treated with maleic anhydride.

Developing and Evaluating Composites Based on Plantation Eucalyptus Rotary-cut Veneer and High-density Polyethylene Film as Novel Building Materials

Directory of Open Access Journals (Sweden)

Wei Song

2016-02-01

Full Text Available To achieve value-added utilizations of plantation timbers, eucalyptus veneer/high-density polyethylene film composites were prepared, with process-factors (PF (hot-pressing temperature, HT; hot-pressing duration, HD; hot-pressing pressure, HP; HDPE-film content, HC and composite-properties (CP (water-resistant bonding-strength, BS; modulus of rupture, MOR; modulus of elasticity, MOE investigated. According to thermal analyses, 140 to 180 °C was appropriate for HT. Based on statistical analyses, HD was easier to affect CP, while MOE was easier to be affected by PF. Quantitative relationships between PF and CP were determined by the neural-network (ANN modeling. In ANN simulation surveys, CP displayed Gaussian distributions (R2 > 0.9 when PF changed in current ranges, with positive correlations between BS and MOR (R2 ≈ 0.5. Combining ANN and the genetic-algorithm, optimal processes (HT, 160 °C; HD, 50 s/mm; HP, 1.3 MPa; HC, 6 layers were found, and optimal results (BS, 1.30 MPa; MOR, 86.94 MPa; MOE, 8.33 GPa were comparable to various reported poplar-plywoods. Microscopic images demonstrated that composite interfaces were formed by the mechanical interlocking. The optimal BS attained Chinese standards for water-resistant plywoods, so proposed composites can serve as water-resistant and formaldehyde-free building materials for furniture and interior design.

Structural, luminescent and thermal properties of blue SrAl{sub 2}O{sub 4}:Eu{sup 2+}, Dy{sup 3+} phosphor filled low-density polyethylene composites

Energy Technology Data Exchange (ETDEWEB)

Bem, D.B. [Department of Physics, University of the Free State (Qwaqwa Campus), Private Bag X13, Phuthaditjhaba 9866 (South Africa); Luyt, A.S. [Department of Chemistry, University of the Free State (Qwaqwa Campus), Private Bag X13, Phuthaditjhaba 9866 (South Africa); Dejene, F.B., E-mail: dejenebf@qwa.ufs.ac.z [Department of Physics, University of the Free State (Qwaqwa Campus), Private Bag X13, Phuthaditjhaba 9866 (South Africa); Botha, J.R. [Department of Physics, Nelson Mandela Metropolitan University, P.O. Box 70000, Port Elizabeth 6031 (South Africa); Swart, H.C. [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein 9300 (South Africa)

2009-12-01

The performance of nanophase luminophors is usually compromised by environmentally induced degradation. In this study, composites of low density polyethylene (LDPE) with various concentrations of the blue-emitting europium and dysprosium co-doped strontium aluminate (SrAl{sub 2}O{sub 4}:Eu{sup 2+},Dy{sup 3+}) phosphor were investigated. The blue long-lasting phosphorescence of the composites was observed in the dark after removal of the excitation light. X-ray diffraction analysis revealed the presence of the SrAl{sub 2}O{sub 4} phase in the composites. PL spectra of the composites have two sets of peaks, major broad bands peaking at about 4855 A and minor ones at wavelengths between 4115 and 4175 A, attributed to the 4f-5d transition of Eu{sup 2+}. DSC and TGA results show that the introduction of the phosphor in LDPE matrix caused a slight reduction in the crystallinity of LDPE but a significant increase in the stability of the composites.

Mechanical and morphological study of linear low density polyethylene (LLDPE)/cyperus odoratus (CY) biocomposites

Science.gov (United States)

Faris, N. A.; Noriman, N. Z.; Haron, Adli; Sam, S. T.; Hamzah, R.; Shayfull, Z.; Ghazali, M. F.

2017-09-01

The potential of Cyperus Odoratus (CY) as a filler was studied. The CY, in a powder form, was mixed with Linear Low Density Polyethylene (LLDPE), prior to being fed into a twin screw extruder and subsequently into an injection moulding machine to produce LLDPY/CY biocomposites. The Scanning Electron Microscope (SEM) was utilized and tensile tests were performed on the test specimens to characterize the structure and properties of the composites. The integration of CY powder and LLDPE resulted in an increment of the modulus of elasticity, but a reduction in tensile strength and elongation at break. The morphology characterization of these composites, determined through the SEM, showed poor interfacial adhesion between the filler and the thermoplastic LLDPE matrix.

High-density polyethylene dosimetry by transvinylene FTIR analysis

DEFF Research Database (Denmark)

McLaughlin, W.L.; Silverman, J.; Al-Sheikhly, M.

1999-01-01

and electrons. The useful dose range of 0.053 cm thick high-density polyethylene film (rho = 0.961 g cm(-3); melt index = 0.8 dg min(-1)), for irradiations by (60)Co gamma radiation and 2.0 and 0.4 MeV electron beams in deaerated atmosphere (Na gas), is about 50-10(3) kGy for FTIR transvinylene......The formation of transvinylene unsaturation, -CH=CH-, due to free-radical or cationic-initiated dehydrogenation by irradiation, is a basic reaction in polyethylene and is useful for dosimetry at high absorbed doses. The radiation-enhanced infrared absorption having a maximum at nu = 965 cm......(-l) (lambda = 10.36 mu m) is stable in air and can be measured by Fourier-transform infrared (FTIR) spectrophotometry. The quantitative analysis is a useful means of product end-point dosimetry for radiation processing with gamma rays and electrons, where polyethylene is a component of the processed product...

MECHANICAL PROPERTIES AND WATER ABSORPTION OF KENAF POWDER FILLED RECYCLED HIGH DENSITY POLYETHYLENE/NATURAL RUBBER BIOCOMPOSITES USING MAPE AS A COMPATIBILIZER

Directory of Open Access Journals (Sweden)

Azura A. Rashid

2011-06-01

Full Text Available The performance of kenaf powder (KP filled recycled high density polyethylene (rHDPE /natural rubber (NR blends with and without a compatibilizer, maleic anhydride grafted polyethylene (MAPE, were investigated. The composites with different filler loading (0 to 40 phr were prepared with a Haake internal mixer. Increasing the KP loading in rHDPE/NR/KP biocomposites reduced the tensile strength and the elongation at break but increased the stabilization torque and the tensile modulus. The addition of MAPE as a compatibilizer increased the tensile strength, elongation at break, and modulus of the composites. This might be attributed to the enhanced adhesion between the filler and polymer matrix, as evidenced from the morphology, using scanning electron microscopy. The incorporation of compatibilizer also reduced the water absorption of the composites.

Production and Structural Investigation of Polyethylene Composites with Modified Kaolin

International Nuclear Information System (INIS)

Domka, L.; Malicka, A.; Stachowiak, N.

2008-01-01

The study was undertaken to evaluate the effect of the filler (kaolin) modification with silane coupling agents on the properties of the polyethylene (HDPE Hostalen ACP 5831) composites. Powder mineral fillers are added to polymers to modify the properties of the latter and to reduce the cost of their production. A very important factor is the filler dispersion in the polymer matrix. Kaolin modified with 3-methacryloxypropyltrimethoxysilane and pure kaolin were characterised by surface area, pore size, water absorbing capacity, paraffin oil absorbing capacity, bulk density, scanning electron microscopy observations and X-ray diffraction measurements. Their performance was characterised by determination of the mechanical resistance upon static stretching and tearing, and their structure was observed in scanning electron microscopy images. The results were compared to those obtained for the composites with unmodified filler and pure HDPE. (authors)

Production and Structural Investigation of Polyethylene Composites with Modified Kaolin

Science.gov (United States)

Domka, L.; Malicka, A.; Stachowiak, N.

2008-08-01

The study was undertaken to evaluate the effect of the filler (kaolin) modification with silane coupling agents on the properties of the polyethylene (HDPE Hostalen ACP 5831) composites. Powder mineral fillers are added to polymers to modify the properties of the latter and to reduce the cost of their production. A very important factor is the filler dispersion in the polymer matrix. Kaolin modified with 3-methacryloxypropyltrimethoxysilane and pure kaolin were characterised by surface area, pore size, water absorbing capacity, paraffin oil absorbing capacity, bulk density, scanning electron microscopy observations and X-ray diffraction measurements. Their performance was characterised by determination of the mechanical resistance upon static stretching and tearing, and their structure was observed in scanning electron microscopy images. The results were compared to those obtained for the composites with unmodified filler and pure HDPE.

Graphite nanoplatelets and carbon nanotubes based polyethylene composites: Electrical conductivity and morphology

International Nuclear Information System (INIS)

Haznedar, Galip; Cravanzola, Sara; Zanetti, Marco; Scarano, Domenica; Zecchina, Adriano; Cesano, Federico

2013-01-01

Graphite nanoplatelets (GNPs) and/or multiwalled-carbon nanotubes (MWCNTs)/low density polyethylene (LDPE) composites have been obtained either via melt-mixing or solvent assisted methods. Electrical properties of samples obtained through the above mentioned methods are compared and the conductance values as function of filler fraction are discussed. The corresponding percolation thresholds are evaluated. Conductivity maps images are acquired under low-potentials scanning electron microscopy (0.3 KV) and the relationship between the obtained conductivity images and electric properties is highlighted. The synergistic role of CNTs (1D) and GNPs (2D) in improving the conductive properties of the polymer composites has been shown. - Highlights: • Graphite nanoplatelets (GNPs) and GNPs/MWCNT LDPE composites. • Low potential SEM conductivity maps. • Conducting paths between 1D and 2D C-structures (synergistic effect) are obtained. • Composites based on hybrid 1D/2D combinations show lower percolation thresholds

Shape Memory Polymer Composites of Poly(styrene-b-butadiene-b-styrene Copolymer/Liner Low Density Polyethylene/Fe3O4 Nanoparticles for Remote Activation

Directory of Open Access Journals (Sweden)

Yongkun Wang

2016-11-01

Full Text Available Magnetically sensitive shape memory poly(styrene-b-butadiene-b-styrene copolymer (SBS/liner low density polyethylene (LLDPE composites filled with various contents of Fe3O4 nanoparticles were prepared. The influence of the Fe3O4 nanoparticles content on the thermal properties, mechanical properties, fracture morphology, magnetic behavior, and shape memory effect of SBS/LLDPE/Fe3O4 composites was systematically studied in this paper. The results indicated that homogeneously dispersed Fe3O4 nanoparticles ensured the uniform heat generation and transfer in the alternating magnetic field, and endowed the SBS/LLDPE/Fe3O4 composites with an excellent magnetically responsive shape memory effect. When the shape memory composites were in the alternating magnetic field (f = 60 kHz, H = 21.21 kA·m−1, the best shape recovery ratio reached 99%, the shape retention ratio reached 99.4%, and the shape recovery speed increased significantly with the increment of Fe3O4 nanoparticles. It is anticipated that tagging products with this novel shape memory composite is helpful for the purpose of an intravascular delivery system in Micro-Electro-Mechanical System (MEMS devices.

Influence of fast neutrons on thermophysical properties of pure and borated low density polyethylene

International Nuclear Information System (INIS)

El-Khatib, A. M.; Kassem, M.

1990-01-01

The impact of radiation crosslinking on the mechanical, thermomechanical and electrical conductivity properties of LDPE and borated polyethylene have been studied and evaluated. The 8% borated polyethylene samples have added a new advantage where the tensile strength has increased to the maximum and then it became constant at higher crosslink density. Moreover, the electrical conductivity of 8% borated polyethylene is much higher than pure and 4% borated polyethylene. (author). 16 refs., 8 figs

Influence of Glycidyl Methacrylate Grafting on the Mechanical, Water Absorption, and Thermal Properties of Recycled High-Density Polyethylene/Rubber Seed Shell Particle Composites

Directory of Open Access Journals (Sweden)

Kaimeng Xu

2016-01-01

Full Text Available Rubber seed shell (RSS was modified by grafting treatment using glycidyl methacrylate (GMA at various concentrations. The RSS was then used to reinforce high-density polyethylene (HDPE. The effects of modification on the mechanical, water absorption, and thermal properties of the RSS/HDPE composites were studied using a mechanical testing instrument, weighing method, Vicat softening temperature (VST testing, thermogravimetry, and dynamic mechanical analysis. The results showed that the GMA grafting produced an improvement in the flexural and tensile properties of the composites. The water absorption rate of the composites also had an obvious decrease. While a slight increase in VST was found, the various concentrations of GMA showed no improvement in VST. GMA modification also could elevate the thermal stability of the composites at the initial decomposition stage. The optimum grafting concentration of GMA (2.5% led to the lowest thermal weight loss (37.07% and 26.56% during the first and second decomposition stages. The E’ values of the composites had a significant increase with the addition of GMA. There were two peaks of tan δ for the untreated samples, but the modified samples exhibited a shift in the transition peak at higher temperatures; moreover, the second peak disappeared.

An Investigation on Rheology of Peroxide Cross-linking of Low Density Polyethylene

DEFF Research Database (Denmark)

Ghasemi, Ismaeil; Rasmussen, Henrik K.; Szabo, Peter

2005-01-01

One of the most important post-reactor modifications of polyethylene is cross-linking. It improves some properties of polyethylene such as environmental stress cracking resistance, chemical and abrasion resistance, and service temperature. In this study, the effect of peroxide cross-linking on th......One of the most important post-reactor modifications of polyethylene is cross-linking. It improves some properties of polyethylene such as environmental stress cracking resistance, chemical and abrasion resistance, and service temperature. In this study, the effect of peroxide cross......-linking on the rheological behaviour of low density polyethylene was investigated by using a combination of creep test and differential scanning calorimeter (DSC) in isotherm condition. The used peroxide was di-cumyl peroxide and its concentration was 2 wt%. The experiments were carried out at 150,160, and 170 degrees C...

The Effects of CaCO3 Coated Wood Free Paper Usage as Filler on Water Absorption, Mechanical and Thermal Properties of Cellulose-High Density Polyethylene Composites

Directory of Open Access Journals (Sweden)

Emrah PEŞMAN

2016-11-01

Full Text Available In this study some physical, mechanical and thermal characteristics of high density polyethylene (HDPE and CaCO3 coated/pigmented wood free paper fiber composites were investigated. The fillers used in this study were uncoated cellulose, 5.8 %, 11.5 %, 16.5 % and 23.1 % CaCO3 coated wood free paper fibers. Each filler type was mixed with HDPE at 40% by weight fiber loading. In this case, the ratio of CaCO3 in plastic composites were calculated as 0 %, 2.3 %, 4.6 %, 6.6 % and 9.2 % respectively. Increased CaCO3 ratio improved the moisture resistant, flexural and tensile strength of cellulose-HDPE composites. However, the density of the cellulose-HDPE composites increased with CaCO3 addition. Energy Dispersive Spectroscopy on Scanning Electron Microscope analysis demonstrated the uniform distribution of CaCO3 and cellulose fiber in plastic matrix. In addition, the thermal properties of fiber plastic composites were investigated. The results of Differential scanning calorimetry analysis revealed that the crystallinity of the samples decreased with increasing CaCO3 content. Consequently, this work showed that CaCO3 coated waste paper fibers could be used as reinforcing filler against water absorption in thermoplastic matrix.DOI: http://dx.doi.org/10.5755/j01.ms.22.4.14222

Mechanical and Thermal Properties of Bamboo Pulp Fiber Reinforced Polyethylene Composites

Directory of Open Access Journals (Sweden)

Wenhan Ren

2014-05-01

Full Text Available The purpose of this study was to investigate the mechanical and thermal properties of high-density polyethylene (HDPE composites reinforced by bamboo pulp fibers (BPF. Using a twin-screw extruder, polymer composites were fabricated using BPF and bamboo flour (BF as the reinforcement and HDPE as the matrix. Tensile and flexural tests of the HDPE composites were performed to determine the mechanical properties under different conditions. The thermal properties of HDPE composites were characterized by thermogravimetric analysis (TGA and dynamic mechanical analysis (DMA. The results showed that BPF improved the mechanical and thermal properties of the polymer composites more than did BF. The tensile and flexural strength of composites with 30 wt% BPF were increased by 61.46% and 22.94%, respectively, while the tensile and flexural modulus were increased by 84.52% and 27.30%, respectively. Compared to composites with 50 wt% BF, the T5% of composites with 50 wt% BPF increased by 20.18 °C. As the BPF content increased, the storage modulus (E’ and loss modulus (E” initially increased, followed by a decrease. Compared to the BF/HDPE composites, BPF/HDPE composites reinforced at 30 wt% had a higher storage modulus (E’ and loss modulus (E” and lower damping parameter (tanδ.

Radiation-Induced Grafting with One-Step Process of Waste Polyurethane onto High-Density Polyethylene

Directory of Open Access Journals (Sweden)

Jong-Seok Park

2015-12-01

Full Text Available The recycling of waste polyurethane (PU using radiation-induced grafting was investigated. The grafting of waste PU onto a high-density polyethylene (HDPE matrix was carried out using a radiation technique with maleic anhydride (MAH. HDPE pellets and PU powders were immersed in a MAH-acetone solution. Finally, the prepared mixtures were irradiated with an electron beam accelerator. The grafted composites were characterized by Fourier transformed infrared spectroscopy (FT-IR, surface morphology, and mechanical properties. To make a good composite, the improvement in compatibility between HDPE and PU is an important factor. Radiation-induced grafting increased interfacial adhesion between the PU domain and the HDPE matrix. When the absorbed dose was 75 kGy, the surface morphology of the irradiated PU/HDPE composite was nearly a smooth and single phase, and the elongation at break increased by approximately three times compared with that of non-irradiated PU/HDPE composite.

Large-scale fabrication of linear low density polyethylene/layered double hydroxides composite films with enhanced heat retention, thermal, mechanical, optical and water vapor barrier properties

Energy Technology Data Exchange (ETDEWEB)

Xie, Jiazhuo; Zhang, Kun; Zhao, Qinghua [College of Chemistry and Material Science, Shandong Agricultural University, 61 Daizong Street, Tai' an 271018 (China); Wang, Qingguo, E-mail: wqgyyy@126.com [College of Food Science and Engineering, Shandong Agricultural University, 61 Daizong Street, Tai' an 271018 (China); Xu, Jing, E-mail: jiaxu@sdau.edu.cn [College of Chemistry and Material Science, Shandong Agricultural University, 61 Daizong Street, Tai' an 271018 (China)

2016-11-15

Novel LDH intercalated with organic aliphatic long-chain anion was large-scale synthesized innovatively by high-energy ball milling in one pot. The linear low density polyethylene (LLDPE)/layered double hydroxides (LDH) composite films with enhanced heat retention, thermal, mechanical, optical and water vapor barrier properties were fabricated by melt blending and blowing process. FT IR, XRD, SEM results show that LDH particles were dispersed uniformly in the LLDPE composite films. Particularly, LLDPE composite film with 1% LDH exhibited the optimal performance among all the composite films with a 60.36% enhancement in the water vapor barrier property and a 45.73 °C increase in the temperature of maximum mass loss rate compared with pure LLDPE film. Furthermore, the improved infrared absorbance (1180–914 cm{sup −1}) of LLDPE/LDH films revealed the significant enhancement of heat retention. Therefore, this study prompts the application of LLDPE/LDH films as agricultural films with superior heat retention. - Graphical abstract: The fabrication process of LLDPE/LDH composite films. - Highlights: • LDH with basal spacing of 4.07 nm was synthesized by high-energy ball milling. • LLDPE composite films with homogeneous LDH dispersion were fabricated. • The properties of LLDPE/LDH composite films were improved. • LLDPE/LDH composite films show superior heat retention property.

Large-scale fabrication of linear low density polyethylene/layered double hydroxides composite films with enhanced heat retention, thermal, mechanical, optical and water vapor barrier properties

International Nuclear Information System (INIS)

Xie, Jiazhuo; Zhang, Kun; Zhao, Qinghua; Wang, Qingguo; Xu, Jing

2016-01-01

Novel LDH intercalated with organic aliphatic long-chain anion was large-scale synthesized innovatively by high-energy ball milling in one pot. The linear low density polyethylene (LLDPE)/layered double hydroxides (LDH) composite films with enhanced heat retention, thermal, mechanical, optical and water vapor barrier properties were fabricated by melt blending and blowing process. FT IR, XRD, SEM results show that LDH particles were dispersed uniformly in the LLDPE composite films. Particularly, LLDPE composite film with 1% LDH exhibited the optimal performance among all the composite films with a 60.36% enhancement in the water vapor barrier property and a 45.73 °C increase in the temperature of maximum mass loss rate compared with pure LLDPE film. Furthermore, the improved infrared absorbance (1180–914 cm −1 ) of LLDPE/LDH films revealed the significant enhancement of heat retention. Therefore, this study prompts the application of LLDPE/LDH films as agricultural films with superior heat retention. - Graphical abstract: The fabrication process of LLDPE/LDH composite films. - Highlights: • LDH with basal spacing of 4.07 nm was synthesized by high-energy ball milling. • LLDPE composite films with homogeneous LDH dispersion were fabricated. • The properties of LLDPE/LDH composite films were improved. • LLDPE/LDH composite films show superior heat retention property.

Temperature dependence of radiation effects in polyethylene

International Nuclear Information System (INIS)

Wu, G; Katsumura, Y.; Kudoh, H.; Morita, Y.; Seguchi, T.

2000-01-01

Temperature dependence of crosslinking and gas evolution under γ-irradiation was studied for high-density and low-density polyethylene samples in the 30-360degC range. It was found that crosslinking was the predominant process up to 300degC and the gel point decreased with increasing temperature. At above 300degC, however, the gel fraction at a given dose decreased rapidly with temperature and the action of radiation turned to enhance polyethylene degradation. Yields of H 2 and hydrocarbon gases increased with temperature and the compositions of hydrocarbons were dose dependent. (author)

Polyethylene-waste tire dust composites via in situ polymerization

International Nuclear Information System (INIS)

Reyes A, Y. K.; Narro C, R. I.; Ramos A, M. E.; Neira V, M. G.; Diaz E, J.; Enriquez M, F.; Valencia L, L. A.; Saade C, H.; Diaz de L, R.

2014-01-01

Polyethylene/waste tire dust (WTD) composites were obtained by an in situ polymerization technique. The surface of the WTD was modified with deposition of polyethylene by using plasma polymerization. Ethylene polymerization was carried out using bis(cyclopentadienyl) titanium dichloride (Cp 2 TiCl 2 ) as homogeneous metallocenes catalyst, while diethylaluminum chloride (DEAC), ethyl aluminum sesquichloride (EASC) and methyl alumino xane (Mao) were used as co-catalysts at two different [Al]/[Ti] molar ratio. The main characteristics of the obtained polyethylenes were determined by size exclusion chromatography, thermogravimetric analysis, differential scanning calorimetry and wide-angle X-ray diffraction. The results showed that by using EASC and Mao the highest catalytic activities were presented at a [Al]/[Ti] molar ratio of 9.17 and 18.33 respectively. Even though it was possible to obtain polyethylene using WTD (modified or unmodified) the catalytic activity was lower than in the case in which no WTD was added in ethylene polymerization. Scanning transmission electronic microscopy images evidenced that the original morphology of the polyethylenes was not modified by the presence of WTD. (Author)

Polyethylene-waste tire dust composites via in situ polymerization

Energy Technology Data Exchange (ETDEWEB)

Reyes A, Y. K.; Narro C, R. I.; Ramos A, M. E. [Universidad Autonoma de Coahuila, Facultad de Ciencias Quimicas, Blvd. Venustiano Carranza s/n, 25280 Saltillo, Coahuila (Mexico); Neira V, M. G.; Diaz E, J.; Enriquez M, F.; Valencia L, L. A.; Saade C, H.; Diaz de L, R., E-mail: ramon.diazdeleon@ciqa.edu.mx [Centro de Investigacion en Quimica Aplicada, Blvd. Enrique Reyna Hermosillo No. 40, Col. San Jose de los Cerritos, 25293 Saltillo, Coahuila (Mexico)

2014-10-01

Polyethylene/waste tire dust (WTD) composites were obtained by an in situ polymerization technique. The surface of the WTD was modified with deposition of polyethylene by using plasma polymerization. Ethylene polymerization was carried out using bis(cyclopentadienyl) titanium dichloride (Cp{sub 2}TiCl{sub 2}) as homogeneous metallocenes catalyst, while diethylaluminum chloride (DEAC), ethyl aluminum sesquichloride (EASC) and methyl alumino xane (Mao) were used as co-catalysts at two different [Al]/[Ti] molar ratio. The main characteristics of the obtained polyethylenes were determined by size exclusion chromatography, thermogravimetric analysis, differential scanning calorimetry and wide-angle X-ray diffraction. The results showed that by using EASC and Mao the highest catalytic activities were presented at a [Al]/[Ti] molar ratio of 9.17 and 18.33 respectively. Even though it was possible to obtain polyethylene using WTD (modified or unmodified) the catalytic activity was lower than in the case in which no WTD was added in ethylene polymerization. Scanning transmission electronic microscopy images evidenced that the original morphology of the polyethylenes was not modified by the presence of WTD. (Author)

Mechanical properties of low-density polyethylene filled by graphite nanoplatelets

International Nuclear Information System (INIS)

Carotenuto, G; Palomba, M; De Nicola, S; Pullini, D; Horsewell, A; Hansen, T W; Nicolais, L

2012-01-01

The mechanical properties of GNP/LDPE nanocomposites (graphite nanoplatelets/low density polyethylene) have been investigated, in order to establish the effect of nanoscale reinforcement within the polymer matrix. Results show that the presence of the filler does not involve a change in the microscopic structure of the polymer. However, on a macroscopic scale, GNPs limit the mobility of the polymer chains, resulting in an increase in stiffness for the final composite. Orientation of GNPs within the LDPE matrix is also an important issue that affects mechanical properties and it has been evaluated by testing nanocomposites made by different manufacturing techniques (compression moulding and blown extrusion). The comparison between the experimental data and the Halpin–Tsai model shows that the orientation of GNPs due to the extrusion process leads to values of tensile modulus higher than that obtained with the randomly oriented disposition resulting from the compression moulding technique. (paper)

A new look at extensional rheology of low-density polyethylene

DEFF Research Database (Denmark)

Huang, Qian; Mangnus, Marc; Alvarez, Nicolas J.

2016-01-01

The nonlinear rheology of three selected commercial low-density polyethylenes (LDPE) is measured in uniaxial extensional flow. The measurements are performed using three different devices including an extensional viscosity fixture (EVF), a homemade filament stretching rheometer (DTU-FSR) and a co...

Thermal Cracking of Low Density Polyethylene (LDPE) Waste into ...

African Journals Online (AJOL)

Waste low density polyethylene film (table water sachets) was converted into solid, liquid oil and gaseous products by thermal process in a self- designed stainless steel laboratory reactor. The waste polymer was completely pyrolized within the temperature range of 474 – 520°C and 2hours reaction time. The solid residue ...

Thermal Experimental Analysis for Dielectric Characterization of High Density Polyethylene Nanocomposites

Directory of Open Access Journals (Sweden)

Ahmed Thabet Mohamed

2016-01-01

Full Text Available The importance of nanoparticles in controlling physical properties of polymeric nanocomposite materials leads us to study effects of these nanoparticles on electric and dielectric properties of polymers in industry In this research, the dielectric behaviour of High-Density Polyethylene (HDPE nanocomposites materials that filled with nanoparticles of clay or fumed silica has been investigated at various frequencies (10 Hz-1 kHz and temperatures (20-60°C. Dielectric spectroscopy has been used to characterize ionic conduction, then, the effects of nanoparticles concentration on the dielectric losses and capacitive charge of the new nanocomposites can be stated. Capacitive charge and loss tangent in high density polyethylene nanocomposites are measured by dielectric spectroscopy. Different dielectric behaviour has been observed depending on type and concentration of nanoparticles under variant thermal conditions.

Thermoluminescence glow curves of irradiated PMMA and low density polyethylene

International Nuclear Information System (INIS)

Matsuda, Koji; Nakase, Yoshiaki; Kumakiri, Yasuhito; Tsuji, Yoshio.

1985-03-01

Light emission from polymers is observed when polymers preirradiated with ionizing radiation at low temperature are heated gradually. The light emission is supposedly resulted from recombination of electrons with active centers produced in polymers or from some other processes involving charge transfer, but no definite explanation has been given at present on the thermoluminescent centers. This report describes our studies on the effects of impurities contained in polymers and pressure of ambient gases on the thermoluminescent glow curve of PMMA and low density polyethylene, which are often used for plastic film dosimeters. In the glow curve of PMMA, only one peak was observed at 110 K in an H 2 or He atmosphere at 760 Torr, but the intensity of the peak decreased with decreasing the H 2 or He gas pressure. At 10 -5 Torr H 2 or He atmosphere the peak disappered, and two sharp peaks appeared in the temperature range from 200 to 250 K. On the other hand, in the glow curve of low density polyethylene, three peaks were observed at 120 K, 180 K and 250 K in the presence of H 2 or He gas at 760 Torr. The effects of pressure of ambient gases and impurities in the polyethylene on these peaks indicate that the peak at 120 K is due to luminescent center produced on the surface or just below the surface of the matrix by collision of excited atoms or molecules of gases with polymer molecules, the peak at 120 K is originated from impurities in the matrix, and the peak at 250 0 K corresponds to luminescent center produced in polyethylene matrix. (author)

Effect of wood flour content on the optical color, surface chemistry, mechanical and morphological properties of wood flour/recycled high density polyethylene (rHDPE) composite

Science.gov (United States)

Sheng, Chan Kok; Amin, Khairul Anuar Mat; Kee, Kwa Bee; Hassan, Mohd Faiz; Ali, E. Ghapur E.

2018-05-01

In this study, effect of wood flour content on the color, surface chemistry, mechanical properties and surface morphology of wood-plastic composite (WPC) on different mixture ratios of recycled high density polyethylene (rHDPE) and wood flour were investigated in detail. The presence of wood flour in the composite indicates a significant total color change and a decrease of lightness. Functional groups of wood flour in WPC can be seen clearer from the Fourier transform infrared (FTIR) spectra as the wood flour content increases. The mechanical tensile testing shows that the tensile strength of Young's modulus is improved, whereas the strain and elongation at break were reduced by the addition of wood flour. The gap between the wood flour microvoid fibre and rHDPE matrix becomes closer when the wood flour content is increased as observed by scanning electron microscope (SEM) image. This finding implies a significant improvement on the interaction of interfacial adhesion between the rHDPE matrix and wood flour filler in the present WPC.

Investigation of utilization of process of polyethylene waste of low density for creation of competitive materials with application of phenol formaldehyde oligomers

International Nuclear Information System (INIS)

Agakishieva, M.A.; Bilalov, Ya. M; Ibragimova, S. M; Dadasheva, G. I; Rezaei, Rudabeh

2007-01-01

Full text: The possibility of the utilization of low density polyethylene wastes by means of their modification with phenol formaldehyde oligomers (Ph FO) and PhFO with the thiourathenes has been investigation. Theology properties of the investigated systems showed that the obtained compositions can be able to be processed by the ordinary methods such as extrusion and casting

Fabrication and materials properties of high-density polyethylene (HDPE)/biphasic calcium phosphate (BCP) hybrid bone plates

International Nuclear Information System (INIS)

Jo, Sun Young; Youn, Min Ho; Lim, Youn Mook; Gwon, Hui Jeong; Park, Jong Seok; Nho, Young Chang

2010-01-01

Biphasic calcium phosphate-reinforced high-density polyethylene (BCP/HDPE) hybrid composite is a new orthopedic biomaterial, which was made to simulate a natural bone composition. Calcium phosphate systems and HDPE hybrid composites have been used in biomedical applications without any inflammatory response. Differences in natural bone of both materials have motivated the use of coupling agents to improve their interfacial interfacial interactions. The composites were prepared using medical grade BCP powder and granular polyethylene. This material was produced by replacing the mineral component and collagen soft tissue of the bone with BCP and HDPE, respectively. As expected, increased volume fraction of either reinforcement type over 0 ∼ 50 vol.% resulted in a increased Vickers hardness and Young's modulus. Thus, BCP particle-reinforced HDPE composites possessed improved material and mechanical properties. BCP particles-reinforced composites were anisotropic due to an alignment of the particles in the matrix during a processing. On the other hand, bending and tensile strength was dramatically changed in the matrix. To change the material and mechanical properties of HDPE/BCP composites, the process of a blending was used, and its effect on the microstructure and mechanical proprieties of HDPE/BCP composites were investigated by means of FT-IR/ATR spectroscopy, XRD, FE-SEM, Vickers Hardness Testing Machine, Universal Testing Machine, Mercury Porosimeter and Ultrasonic Flaw Detector at room temperature. For the evaluation of the cell viability and proliferation onto the external surface of HDPE/BCP hybrid plates with a HaCaT cell line, which is a multipotent cell line able to differentiate towards different phenotypes under the action of biological factors, has been evaluated with in vitro studies and quantified by colormetric assays. These findings indicate that the HDPE/BCP hybrid plates are biocompatible and non-toxic

Preparation and properties studies of halogen-free flame retardant form-stable phase change materials based on paraffin/high density polyethylene composites

International Nuclear Information System (INIS)

Cai Yibing; Wei Qufu; Huang Fenglin; Gao Weidong

2008-01-01

The halogen-free flame retardant form-stable phase change materials (PCM) based on paraffin/high density polyethylene (HDPE) composites were prepared by using twin-screw extruder technique. The structures and properties of the form-stable PCM composites based on intumescent flame retardant system with expandable graphite (EG) and different synergistic additives, such as ammonium polyphosphate (APP) and zinc borate (ZB) were characterized by scanning electronic microscope (SEM), thermogravimetric analyses (TGA), dynamic Fourier-transform infrared (FTIR) spectra, differential scanning calorimeter (DSC) and Cone calorimeter test. The TGA results showed that the halogen-free flame retardant form-stable PCM composites produced a larger amount of charred residue at 700 deg. C, although the onset of weight loss of the halogen-free flame retardant form-stable PCM composites occurred at a lower temperature due to the thermal decomposition of flame retardant. The DSC measurements indicated that the additives of flame retardant had little effect on the thermal energy storage property, and the temperatures of phase change peaks and the latent heat of the paraffin showed better occurrence during the freezing process. The dynamic FTIR monitoring results revealed that the breakdowns of main chains (HDPE and paraffin) and formations of various residues increased with increasing thermo-oxidation temperature. It was also found from the Cone calorimeter tests that the peak of heat release rate (PHRR) decreased significantly. Both the decrease of the PHRR and the structure of charred residue after combustion indicated that there was a synergistic effect between the EG and APP, contributing to the improved flammability of the halogen-free flame retardant form-stable PCM composites

Electrical and mechanical properties of highly elongated high density polyethylene as cryogenic insulation materials

International Nuclear Information System (INIS)

Yoshino, Katsumi; Park, Dae-Hee; Miyata, Kiyomi; Yamaoka, Hitoshi; Itoh, Minoru; Ichihara, Syouji.

1989-01-01

Electrical and mechanical properties of highly elongated high density polyethylene were investigated in the temperature range between 4.2 K and 400 K from a viewpoint of electrical insulation at low temperature and the following properties have been clarified. (1) The electrical conductivity of samples decreases with increasing draw ratio, and also decreases at cryogenic temperature. (2) Breakdown strength of highly elongated sample is similar to that of non-elongated sample. It is nearby temperature independent below 300 K but at higher temperature it falls steeply. (3) Mechanical breakdown stress and elastic modulus of high density polyethylene increase with increasing draw ratio. Their values at liquid nitrogen temperature are much higher than that at room temperature. On the other hand, strains decreases at liquid nitrogen temperature. (4) Break of the sample develops in the direction of 45deg from the direction of stress both at room temperature and at cryogenic temperature. (5) The characteristic of mechanical breakdown at liquid nitrogen temperature can be explained by a brittleness fracture process. (6) Toughness of high density polyethylene increases with increasing draw ratio until draw ratio of 5, and it decreased, and increase at higher draw ratio. However at extremely high draw ratio of 10 it again increases. These findings clearly indicate that highly elongated high density polyethylene has good electrical and mechanical properties at cryogenic temperature and can be used as the insulating materials at cryogenic temperature. (author)

Preparation and Characterisation of Linear Low-Density Polyethylene / Thermoplastic Starch Blends Filled with Banana Fibre

Science.gov (United States)

Kahar, A. W. M.; Ann, L. Ju

2017-06-01

In this study, the influence of banana fibre (BF) loading using sodium hydroxide (NaOH) pre-treated and succinic anhydride-treated (SA) BF on the mechanical properties of linear low-density polyethylene (LLDPE)/thermoplastic starch (TPS) matrix is investigated. LLDPE/TPS/BF composites were developed under different BF conditions, with and without chemical modifications with the BF content ranging from 5% to 30% based on the total composite. The tensile strength showed an increase with an increase of fibre content up to 10%, thereby decreasing gradually beyond this level. NaOH pre-treated and SA treated BF added with LLDPE/TPS composite displays a higher tensile strength as compared to untreated BF in LLDPE/TPS composites. Thermal behaviour of the BF incorporated in LLDPE/TPS composite was characterised using differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). This showed that SA treated BF exhibits better thermal stability, compared to other composites. This is because of the improvement in interfacial adhesion existing between both the fibre and matrix. In addition, a morphology study confirmed that pre-treated and treated BF had excellent interfacial adhesion with LLDPE/TPS matrix, leading to better mechanical properties of resultant composites.

A complete life cycle assessment of high density polyethylene plastic bottle

Science.gov (United States)

Treenate, P.; Limphitakphong, N.; Chavalparit, O.

2017-07-01

This study was aimed to determine environmental performances of a lubricant oil bottle made from high density polyethylene and to develop potential measures for reducing its impacts. A complete life cycle assessment was carried out to understand a whole effect on the environment from acquiring, processing, using, and disposing the product. Two scenarios of disposal phase; recycle and incineration: were examined to quantify a lesser degree on environmental impact. The results illustrated that major impacts of the two scenarios were at the same categories with the highest contributor of raw material acquisition and pre-processing. However, all impacts in case of recycling provided a lower point than that in case of incineration, except mineral extraction. Finally, feasible measures for reducing the environmental impact of high density polyethylene plastic bottle were proposed in accordance with 3Rs concept.

Effect of high energy electron beam (10 MeV) on specific heat capacity of low-density polyethylene/hydroxyapatite nano-composite

Energy Technology Data Exchange (ETDEWEB)

Soltani, Z., E-mail: zhr_soltani@yahoo.com [Health Physics and Radiation Dosimetry Research Laboratory, Department of Energy Engineering and Physics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Ziaie, F. [Radiation Application Research School, Nuclear Science & Technology Research Institute, Tehran (Iran, Islamic Republic of); Ghaffari, M. [Polymer Group, Golestan University, Golestan (Iran, Islamic Republic of); Beigzadeh, A.M. [Radiation Application Research School, Nuclear Science & Technology Research Institute, Tehran (Iran, Islamic Republic of)

2017-02-01

In the present work, thermal properties of low density polyethylene (LDPE) and its nano composites are investigated. For this purpose LDPE reinforced with different weight percents of hydroxyapatite (HAP) powder which was synthesized via hydrolysis method are produced. The samples were irradiated with 10 MeV electron beam at doses of 75 to 250 kGy. Specific heat capacity measurement have been carried out at different temperatures, i.e. 25, 50, 75 and 100 °C using modulated temperature differential scanning calorimetry (MTDSC) apparatus and the effect of three parameters include of temperature, irradiation dose and the amount of HAP nano particles as additives on the specific heat capacity of PE/HAP have been investigated precisely. The MTDSC results indicate that the specific heat capacity have decreased by addition of nano sized HAP as reinforcement for LDPE. On the other hand, the effect of radiation dose is reduction in the specific heat capacity in all materials including LDPE and its nano composites. The HAP nano particles along with cross-link junctions due to radiation restrain the movement of the polymer chains in the vicinity of each particle and improve the immobility of polymer chains and consequently lead to reduction in specific heat capacity. Also, the obtained results confirm that the radiation effect on the specific heat capacity is more efficient than the reinforcing effect of nano-sized hydroxyapatite.

Influence of flavour absorption by food-packaging materials (low-density polyethylene, polycarbonate and polyethylene terephthalate) on taste perception of a model solution and orange juice

NARCIS (Netherlands)

Willige, van R.W.G.; Linssen, J.P.H.; Legger, A.; Voragen, A.G.J.

2003-01-01

The influence of flavour absorption by low-density polyethylene (LDPE), polycarbonate (PC) and polyethylene terephthalate (PET) on taste perception of a model solution containing seven flavour compounds and orange juice in glass bottles was studied with and without pieces of the respective plastic

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

Zinc layered hydroxide salts: intercalation and incorporation into low-density polyethylene

Directory of Open Access Journals (Sweden)

Silvia Jaerger

2014-12-01

Full Text Available In this study, polymer composites using low-density polyethylene (LDPE and layered hydroxide salts (LHS were synthesized. The following compositions of LHS were obtained Zn5(OH8(An-2/n.yH2O, where A was varied in order to obtain hydrophilic (A = NO3- or hydrophobic (A = DDS- - dodecyl sulfate or DBS- - dodecyl benzene sulfonate. Synthesis was carried out by co-precipitation in alkaline medium and drying, being followed by characterization via Fourier-transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction and scanning electron microscopy. A variable amount of filler was then incorporated into the LDPE via extrusion, which was then injection molded to obtain specimens for evaluating tensile properties (Young's modulus, tensile strength, strain at break and toughness. For comparison, the sodium salts of the surfactants (NaDDS and NaDBS were also used as fillers in LDPE. The X-ray diffraction results indicated that the hydrophobic LHS were exfoliated in the polymer matrix, whereas the hydrophilic LHS was only delaminated. In the LDPE composites, melting and crystallization temperatures were nearly constant, along with the crystallinity indexes. The mechanical properties were mainly varied when the organophilic LHS was used. Overall, fillers based on LHS, especially those containing hydrophobic anions, may be interesting alternatives in the production of reinforced thermoplastics.

Effect of γ-aminopropyltriethoxy silane (γ-APS) coupling agent on mechanical and morphological properties of high density polyethylene (HDPE)/acrylonitrile butadiene rubber (NBR)/palm pressed fibre (PPF) composites

Science.gov (United States)

Norizan, Nabila Najwa; Santiagoo, Ragunathan; Ismail, Hanafi

2017-07-01

The fabrication of High Density Polyethylene (HDPE)/ Acrylonitrile-butadiene rubber (NBR)/ Palm Pressed Fibre (PPF) composite were investigated. The effect of γ-Aminopropyltriethoxy Silane (APS) as coupling agent on the properties of HDPE/ NBR/ PPF composite were studied. The composites were melt mixed using heated two roll mill at 180°C and speed of 15rpm with six different loading (100/0/10, 80/20/10, 70/30/10, 60/40/10, 50/50/10, and 40/60/10). The effects of γ-APS silane on mechanical, and morphological properties were examined using universal tensile machine (UTM) and scanning electron microscopy (SEM), respectively. Tensile strength and Young's modulus of HDPE/ NBR/ PPF composites decrease with increasing of NBR loading, whilst increasing the elongation at break. However, treated composites have resulted 3% to 29%, and 9% to 19%, higher in tensile strength and young's modulus compared to untreated composites. This was due to the better adhesion between HDPE/ NBR matrices and PPF filler with the presence of silanol moieties. From the morphological study, the micrograph of treated composites has proved the well bonded and good attachment of PPF filler with HDPE/ NBR matrices which resulted to better tensile strength to the HDPE/ NBR/ PPF composites.

Investigation of Thermal Properties of High-Density Polyethylene/Aluminum Nanocomposites by Photothermal Infrared Radiometry

Science.gov (United States)

Koca, H. D.; Evgin, T.; Horny, N.; Chirtoc, M.; Turgut, A.; Tavman, I. H.

2017-12-01

In this study, thermal properties of high-density polyethylene (HDPE) filled with nanosized Al particles (80 nm) were investigated. Samples were prepared using melt mixing method up to filler volume fraction of 29 %, followed by compression molding. By using modulated photothermal radiometry (PTR) technique, thermal diffusivity and thermal effusivity were obtained. The effective thermal conductivity of nanocomposites was calculated directly from PTR measurements and from the measurements of density, specific heat capacity (by differential scanning calorimetry) and thermal diffusivity (obtained from PTR signal amplitude and phase). It is concluded that the thermal conductivity of HDPE composites increases with increasing Al fraction and the highest effective thermal conductivity enhancement of 205 % is achieved at a filler volume fraction of 29 %. The obtained results were compared with the theoretical models and experimental data given in the literature. The results demonstrate that Agari and Uno, and Cheng and Vachon models can predict well the thermal conductivity of HDPE/Al nanocomposites in the whole range of Al fractions.

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.

Gamma radiation effects on the rheological properties of high and low density polyethylenes

International Nuclear Information System (INIS)

Rangel-Nafaile, C.; Garcia-Rejon, A.; Garcia Leon, A.

1986-01-01

High energy radiation of polymeric materials is a topic of considerable interest from commercial and scientific points of view. Within an inert atmosphere, irradiation of polyethylene yields a crosslinking effect with a consequent improvement in its mechanical properties in comparison to the virgin materials. Additionally, if irradiated specimens are melted and recrystallized, the radiation-induced crosslinking hinders their crystalline growth altering dramatically their flow properties such as the elasticity. This work portrays the effects of the gamma radiation on the rheological properties of high and low density polyethylenes manufactured by PEMEX and analyzes the implications of theoretical results derived from the Acierno's model when it is implemented with the rheological properties of high energy irradiated polyethylenes. (author)

Form-stable paraffin/high density polyethylene composites as solid-liquid phase change material for thermal energy storage: preparation and thermal properties

International Nuclear Information System (INIS)

Sari, Ahmet

2004-01-01

This paper deals with the preparation of paraffin/high density polyethylene (HDPE) composites as form-stable, solid-liquid phase change material (PCM) for thermal energy storage and with determination of their thermal properties. In such a composite, the paraffin (P) serves as a latent heat storage material and the HDPE acts as a supporting material, which prevents leakage of the melted paraffin because of providing structural strength. Therefore, it is named form-stable composite PCM. In this study, two kinds of paraffins with melting temperatures of 42-44 deg. C (type P1) and 56-58 deg. C (type P2) and latent heats of 192.8 and 212.4 J g -1 were used. The maximum weight percentage for both paraffin types in the PCM composites without any seepage of the paraffin in the melted state were found as high as 77%. It is observed that the paraffin is dispersed into the network of the solid HDPE by investigation of the structure of the composite PCMs using a scanning electronic microscope (SEM). The melting temperatures and latent heats of the form-stable P1/HDPE and P2/HDPE composite PCMs were determined as 37.8 and 55.7 deg. C, and 147.6 and 162.2 J g -1 , respectively, by the technique of differential scanning calorimetry (DSC). Furthermore, to improve the thermal conductivity of the form-stable P/HDPE composite PCMs, expanded and exfoliated graphite (EG) by heat treatment was added to the samples in the ratio of 3 wt.%. Thereby, the thermal conductivity was increased about 14% for the form-stable P1/HDPE and about 24% for the P2/HDPE composite PCMs. Based on the results, it is concluded that the prepared form-stable P/HDPE blends as composite type PCM have great potential for thermal energy storage applications in terms of their satisfactory thermal properties and improved thermal conductivity. Furthermore, these composite PCMs added with EG can be considered cost effective latent heat storage materials since they do not require encapsulation and extra cost to enhance

Synthesis and characterization of gold nanotube/nanowire–polyurethane composite based on castor oil and polyethylene glycol

International Nuclear Information System (INIS)

Ganji, Yasaman; Kasra, Mehran; Salahshour Kordestani, Soheila; Bagheri Hariri, Mohiedin

2014-01-01

Gold nanotubes/nanowires (GNT/NW) were synthesized by using the template-assisted electrodeposition technique and mixed with castor oil–polyethylene glycol based polyurethane (PU) to fabricate porous composite scaffolds for biomedical application. 100 and 50 ppm of GNT/NW were used to synthesize composites. The composite scaffolds were characterized by Fourier transform infrared spectroscopy, dynamic mechanical thermal analysis, differential scanning calorimetry, and scanning electron microscopy. Cell attachment on polyurethane–GNT/NW composites was investigated using fat-derived mesenchymal stem cells. Addition of 50 or 100 ppm GNT/NW had significant effects on thermal, mechanical, and cell attachment of polyurethane. Higher crosslink density and better cell attachment and proliferation were observed in polyurethane containing 50 ppm GNT/NW. The results revealed that GNT/NW formed hydrogen bonding with the polyurethane matrix and improved the thermomechanical properties of nanocomposites. Compared with pure PU, better cellular attachment on polyurethane–GNT/NW composites was observed resulting from the improved surface properties of composites. - Highlights: • Polyurethane–gold nanotubes/nanowires (GNT/NWs) composites were synthesized. • Tan δ, E′ and E″ were increased upon addition of 50 ppm of GNT/NW. • Better cell attachment was observed in composites containing 50 ppm of GNT/NW. • GNT/NWs can make a bridge between the pores of the porous polymeric scaffolds. • GNT/NWs increased the crosslink density of the polymeric matrix

Synthesis and characterization of gold nanotube/nanowire–polyurethane composite based on castor oil and polyethylene glycol

Energy Technology Data Exchange (ETDEWEB)

Ganji, Yasaman, E-mail: y.ganji@aut.ac.ir [Faculty of Biomedical Engineering, Amirkabir University of Technology, 424 Hafez Ave., Tehran (Iran, Islamic Republic of); Kasra, Mehran, E-mail: mkasra@aut.ac.ir [Faculty of Biomedical Engineering, Amirkabir University of Technology, 424 Hafez Ave., Tehran (Iran, Islamic Republic of); Salahshour Kordestani, Soheila, E-mail: s.kordestani@aut.ac.ir [Faculty of Biomedical Engineering, Amirkabir University of Technology, 424 Hafez Ave., Tehran (Iran, Islamic Republic of); Bagheri Hariri, Mohiedin, E-mail: mohibagheri@gmail.com [Materials Science and Engineering Department, Sharif University of Technology, Azadi Ave., Tehran (Iran, Islamic Republic of)

2014-09-01

Gold nanotubes/nanowires (GNT/NW) were synthesized by using the template-assisted electrodeposition technique and mixed with castor oil–polyethylene glycol based polyurethane (PU) to fabricate porous composite scaffolds for biomedical application. 100 and 50 ppm of GNT/NW were used to synthesize composites. The composite scaffolds were characterized by Fourier transform infrared spectroscopy, dynamic mechanical thermal analysis, differential scanning calorimetry, and scanning electron microscopy. Cell attachment on polyurethane–GNT/NW composites was investigated using fat-derived mesenchymal stem cells. Addition of 50 or 100 ppm GNT/NW had significant effects on thermal, mechanical, and cell attachment of polyurethane. Higher crosslink density and better cell attachment and proliferation were observed in polyurethane containing 50 ppm GNT/NW. The results revealed that GNT/NW formed hydrogen bonding with the polyurethane matrix and improved the thermomechanical properties of nanocomposites. Compared with pure PU, better cellular attachment on polyurethane–GNT/NW composites was observed resulting from the improved surface properties of composites. - Highlights: • Polyurethane–gold nanotubes/nanowires (GNT/NWs) composites were synthesized. • Tan δ, E′ and E″ were increased upon addition of 50 ppm of GNT/NW. • Better cell attachment was observed in composites containing 50 ppm of GNT/NW. • GNT/NWs can make a bridge between the pores of the porous polymeric scaffolds. • GNT/NWs increased the crosslink density of the polymeric matrix.

Modification of high density polyethylene by gold implantation using different ion energies

Energy Technology Data Exchange (ETDEWEB)

Nenadović, M.; Potočnik, J. [INS Vinca, Laboratory of Atomic Physics, University of Belgrade, Mike Alasa 12–14, 11001 Belgrade (Serbia); Mitrić, M. [INS Vinca, Condensed Matter Physics Laboratory, University of Belgrade, Mike Alasa 12–14, 11001 Belgrade (Serbia); Štrbac, S. [ICTM Institute of Electrochemistry, University of Belgrade, Njegoseva 12, 11001 Belgrade (Serbia); Rakočević, Z., E-mail: zlatkora@vinca.rs [INS Vinca, Laboratory of Atomic Physics, University of Belgrade, Mike Alasa 12–14, 11001 Belgrade (Serbia)

2013-11-01

High density polyethylene (HDPE) samples were modified by Au{sup +} ion implantation at a dose of 5 × 10{sup 15} ions cm{sup −2}, using energies of 50, 100, 150 and 200 keV. The existence of implanted gold in the near-surface region of HDPE samples was confirmed by X-ray diffraction analysis. Surface roughness and Power Spectral Density analyses based on Atomic Force Microscopy (AFM) images of the surface topography revealed that the mechanism of HDPE modification during gold ion implantation depended on the energy of gold ions. Histograms obtained from phase AFM images indicated a qualitative change in the chemical composition of the surface during implantation with gold ions with different energies. Depth profiles obtained experimentally from cross-sectional Force Modulation Microscopy images and ones obtained from a theoretical simulation are in agreement for gold ions energies lower than 100 keV. The deviation that was observed for higher energies of the gold ions is explained by carbon precipitation in the near surface region of the HDPE, which prevented the penetration of gold ions further into the depth of the sample. - Highlights: • HDPE was implanted by Au{sup +} ions using energies of 50, 100, 150 and 200 keV. • Surface composition was analyzed from phase AFM images. • FMM depth profiles are in agreement with theoretical ones for energies up to 100 keV. • A deviation is observed for higher gold ion energies.

Modification of high density polyethylene by gold implantation using different ion energies

International Nuclear Information System (INIS)

Nenadović, M.; Potočnik, J.; Mitrić, M.; Štrbac, S.; Rakočević, Z.

2013-01-01

High density polyethylene (HDPE) samples were modified by Au + ion implantation at a dose of 5 × 10 15 ions cm −2 , using energies of 50, 100, 150 and 200 keV. The existence of implanted gold in the near-surface region of HDPE samples was confirmed by X-ray diffraction analysis. Surface roughness and Power Spectral Density analyses based on Atomic Force Microscopy (AFM) images of the surface topography revealed that the mechanism of HDPE modification during gold ion implantation depended on the energy of gold ions. Histograms obtained from phase AFM images indicated a qualitative change in the chemical composition of the surface during implantation with gold ions with different energies. Depth profiles obtained experimentally from cross-sectional Force Modulation Microscopy images and ones obtained from a theoretical simulation are in agreement for gold ions energies lower than 100 keV. The deviation that was observed for higher energies of the gold ions is explained by carbon precipitation in the near surface region of the HDPE, which prevented the penetration of gold ions further into the depth of the sample. - Highlights: • HDPE was implanted by Au + ions using energies of 50, 100, 150 and 200 keV. • Surface composition was analyzed from phase AFM images. • FMM depth profiles are in agreement with theoretical ones for energies up to 100 keV. • A deviation is observed for higher gold ion energies

A hierarchical classification approach for recognition of low-density (LDPE) and high-density polyethylene (HDPE) in mixed plastic waste based on short-wave infrared (SWIR) hyperspectral imaging

Science.gov (United States)

Bonifazi, Giuseppe; Capobianco, Giuseppe; Serranti, Silvia

2018-06-01

The aim of this work was to recognize different polymer flakes from mixed plastic waste through an innovative hierarchical classification strategy based on hyperspectral imaging, with particular reference to low density polyethylene (LDPE) and high-density polyethylene (HDPE). A plastic waste composition assessment, including also LDPE and HDPE identification, may help to define optimal recycling strategies for product quality control. Correct handling of plastic waste is essential for its further "sustainable" recovery, maximizing the sorting performance in particular for plastics with similar characteristics as LDPE and HDPE. Five different plastic waste samples were chosen for the investigation: polypropylene (PP), LDPE, HDPE, polystyrene (PS) and polyvinyl chloride (PVC). A calibration dataset was realized utilizing the corresponding virgin polymers. Hyperspectral imaging in the short-wave infrared range (1000-2500 nm) was thus applied to evaluate the different plastic spectral attributes finalized to perform their recognition/classification. After exploring polymer spectral differences by principal component analysis (PCA), a hierarchical partial least squares discriminant analysis (PLS-DA) model was built allowing the five different polymers to be recognized. The proposed methodology, based on hierarchical classification, is very powerful and fast, allowing to recognize the five different polymers in a single step.

Performance of composite sand cement brick containing recycle concrete aggregate and waste polyethylene terephthalate with different mix design ratio

Science.gov (United States)

Azmi, N. B.; Khalid, F. S.; Irwan, J. M.; Mazenan, P. N.; Zahir, Z.; Shahidan, S.

2018-04-01

This study is focuses to the performance of composite sand cement brick containing recycle concrete aggregate and waste polyethylene terephthalate. The objective is to determine the mechanical properties such as compressive strength and water absorption of composite brick containing recycled concrete aggregate and polyethylene terephthalate waste and to determine the optimum mix ratio of bricks containing recycled concrete aggregate and polyethylene terephthalate waste. The bricks specimens were prepared by using 100% natural sand, they were then replaced by RCA at 25%, 50% and 75% with proportions of PET consists of 1.0%, 1.5%, 2.0% and 2.5% by weight of natural sand. Based on the results of compressive strength, it indicates that the replacement of RCA shows an increasing strength as the strength starts to increase from 25% to 50% for both mix design ratio. The strength for RCA 75% volume of replacement started to decrease as the volume of PET increase. However, the result of water absorption with 50% RCA and 1.0% PET show less permeable compared to control brick at both mix design ratio. Thus, one would expect the density of brick decrease and the water absorption to increase as the RCA and PET content is increased.

Effect of Heat Drawing Process on Mechanical Properties of Dry-Jet Wet Spun Fiber of Linear Low Density Polyethylene/Carbon Nanotube Composites

Directory of Open Access Journals (Sweden)

Jong Won Kim

2017-01-01

Full Text Available Polyethylene is one of the most commonly used polymer materials. Even though linear low density polyethylene (LLDPE has better mechanical properties than other kinds of polyethylene, it is not used as a textile material because of its plastic behavior that is easy to break at the die during melt spinning. In this study, LLDPE fibers were successfully produced with a new approach using a dry-jet wet spinning and a heat drawing process. The fibers were filled with carbon nanotubes (CNTs to improve the strength and reduce plastic deformation. The crystallinity, degree of orientation, mechanical properties (strength to yield, strength to break, elongation at break, and initial modulus, electrical conductivity, and thermal properties of LLDPE fibers were studied. The results show that the addition of CNTs improved the tensile strength and the degree of crystallinity. The heat drawing process resulted in a significant increase in the tensile strength and the orientation of the CNTs and polymer chains. In addition, this study demonstrates that the heat drawing process effectively decreases the plastic deformation of LLDPE.

Preparation and characterization of high density polyethylene and residual fibre of Attalea funifera Mart (piacava) composites; Preparacao e caracterizacao de compositos de polietileno de alta densidade com residuos de fibras de piacava da especie Attalea funifera Mart

Energy Technology Data Exchange (ETDEWEB)

Agrela, Sara P.; Guimaraes, Danilo H.; Jose, Nadia M., E-mail: saraagrela@hotmail.co [Universidade Federal da Bahia (GECIM/IQ/UFBA), Salvador, BA (Brazil). Inst. de Quimica. Grupo de Energia e Ciencias dos Materiais; Carvalho, Gleidson G.P. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Escola de Medicina Veterinaria. Dept. de Producao Animal; Carvalho, Ricardo F. [Universidade Federal da Bahia (EP/UFBA), Salvador, BA (Brazil). Escola Politecnica. Curso de Mestrado em Engenharia Ambiental Urbana

2009-07-01

The use of natural fiber reinforcement thermoplastic polymer is continuously increasing. This fact is manly due to its advantages as low cost, availability, recyclability, low energy demand and then environmental appeal if compared to synthetics fibers. The composites were prepared in different fiber volume ratios (5%, 10% and 20%) mixed with high density polyethylene (HDPE) and heated at 190 deg C. Thermogravimetric analysis and differential scanning calorimetry were used to investigate thermal stability. The composites structure was characterized by Fourier Transform Infrared spectroscopy, X-ray diffractometry. Fiber and residue of piassava (Attalea funifera Mart) chemical composition were determined by Van Soest Method. The results indicate that thermo stability of the composites of HDPE prepared with fiber volume ratios up to 20% is only slightly lowered. (author)

Sound Transmission Properties of Mineral-filled High-Density Polyethylene (HDPE and Wood-HDPE Composites

Directory of Open Access Journals (Sweden)

Birm-June Kim

2014-11-01

Full Text Available Wood plastic composites (WPCs offer various advantages and potential as a competitive alternative to conventional noise barriers. For this purpose, the influence of composite formulation on the sound transmission loss (TL of WPCs needs to be fully understood. In TL testing, stiffness and surface density are major factors influencing the sound insulation property of filled plastics and WPCs. Experimental TL values decreased as sound frequency increased; and the TL values increased after passing a certain frequency level. The comparison of experimental TL curves among filled composites showed that the addition of fillers led to an increase in resonance frequency and TL values. However, at high filling levels, the stiffness decrease led to TL reductions. The experimental TL curves of filled composites, composed of mass law and stiffness law predictions, were well approximated with their combined TL predictions.

Method for making a low density polyethylene waste form for safe disposal of low level radioactive material

Science.gov (United States)

Colombo, P.; Kalb, P.D.

1984-06-05

In the method of the invention low density polyethylene pellets are mixed in a predetermined ratio with radioactive particulate material, then the mixture is fed through a screw-type extruder that melts the low density polyethylene under a predetermined pressure and temperature to form a homogeneous matrix that is extruded and separated into solid monolithic waste forms. The solid waste forms are adapted to be safely handled, stored for a short time, and safely disposed of in approved depositories.

Radicals mediated magnetism in Ar plasma treated high-density polyethylene

Science.gov (United States)

Orendáč, M.; Čižmár, E.; Kažiková, V.; Orendáčová, A.; Řezníčková, A.; Kolská, Z.; Švorčík, V.

2018-05-01

Electron-spin resonance of high-density polyethylene treated by Ar plasma at 300 K was performed in X-band at temperatures from 2.1 K to 290 K. The observed spectra suggest presence of allyl radicals, whereas the central peak may be attributed to polyenyl radicals or dangled bonds. Pronounced narrowing of the resonance line observed above glassy temperature of polyethylene may be ascribed to thermally activated motional effect with the activation energy Ea /kB = 160 K. The absence of strong exchange interactions is suggested by negligible exchange narrowing found at 2.1 K. The suggestion is supported by the analysis of the temperature dependence of the intensity at low temperatures, which is explicable assuming the coexistence of non-interacting radicals and S = 1/2 dimers with a distribution of antiferromagnetic couplings varying from 2 K to nominally 25 K.

Synthesis and characterization of gold nanotube/nanowire-polyurethane composite based on castor oil and polyethylene glycol.

Science.gov (United States)

Ganji, Yasaman; Kasra, Mehran; Salahshour Kordestani, Soheila; Bagheri Hariri, Mohiedin

2014-09-01

Gold nanotubes/nanowires (GNT/NW) were synthesized by using the template-assisted electrodeposition technique and mixed with castor oil-polyethylene glycol based polyurethane (PU) to fabricate porous composite scaffolds for biomedical application. 100 and 50 ppm of GNT/NW were used to synthesize composites. The composite scaffolds were characterized by Fourier transform infrared spectroscopy, dynamic mechanical thermal analysis, differential scanning calorimetry, and scanning electron microscopy. Cell attachment on polyurethane-GNT/NW composites was investigated using fat-derived mesenchymal stem cells. Addition of 50 or 100 ppm GNT/NW had significant effects on thermal, mechanical, and cell attachment of polyurethane. Higher crosslink density and better cell attachment and proliferation were observed in polyurethane containing 50 ppm GNT/NW. The results revealed that GNT/NW formed hydrogen bonding with the polyurethane matrix and improved the thermomechanical properties of nanocomposites. Compared with pure PU, better cellular attachment on polyurethane-GNT/NW composites was observed resulting from the improved surface properties of composites. Copyright © 2014 Elsevier B.V. All rights reserved.

Interfacial Shear Strength Evaluation of Pinewood Residue/High-Density Polyethylene Composites Exposed to UV Radiation and Moisture Absorption-Desorption Cycles

Directory of Open Access Journals (Sweden)

Soledad C. Pech-Cohuo

2016-03-01

Full Text Available In outdoor applications, the mechanical performance of wood-plastic composites (WPCs is affected by UV radiation, facilitating moisture intake and damaging the wood-polymer interfacial region. The purpose of this study was to evaluate the effect of moisture absorption-desorption cycles (MADCs, and the exposure to UV radiation on the interfacial shear strength (IFSS of WPCs with 40% pinewood residue and 60% high-density polyethylene. One of the WPCs incorporated 5% coupling agent (CA with respect to wood content. The IFSS was evaluated following the Iosipescu test method. The specimens were exposed to UV radiation using an accelerated weathering test device and subsequently subjected to four MADCs. Characterization was also performed by scanning electron microscopy (SEM and Fourier transform infrared spectroscopy (FTIR. The absorption and desorption of moisture was slower in non-UV-irradiated WPCs, particularly in those with the CA. The UV radiation did not significantly contribute to the loss of the IFSS. Statistically, the CA had a favorable effect on the IFSS. Exposure of the samples to MADCs contributed to reduce the IFSS. The FTIR showed lignin degradation and the occurrence of hydrolysis reactions after exposure to MADCs. SEM confirmed that UV radiation did not significantly affect the IFSS.

THE GRAFTING OF MALEIC-ANHYDRIDE ON HIGH-DENSITY POLYETHYLENE IN AN EXTRUDER

NARCIS (Netherlands)

GANZEVELD, KJ; JANSSEN, LPBM

The grafting of maleic anhydride (MAH) on high density polyethylene in a counter-rotating twin screw extruder has been studied. As the reaction kinetics appear to be affected by mass transfer, good micro mixing in the extruder is important. Due to the competing mechanisms of increasing mixing and

Diffusion of multiwall carbon nanotubes (MWCNTs) through a high density polyethylene (HDPE) geomembrane.

Science.gov (United States)

Saheli, P T; Rowe, R K; Petersen, E J; O'Carroll, D M

2017-05-01

The new applications for carbon nanotubes (CNTs) in various fields and consequently their greater production volume have increased their potential release to the environment. Landfills are one of the major locations where carbon nanotubes are expected to be disposed and it is important to ensure that they can limit the release of CNTs. Diffusion of multiwall carbon nanotubes (MWCNTs) dispersed in an aqueous media through a high-density polyethylene (HDPE) geomembrane (as a part of the landfill barrier system) was examined. Based on the laboratory tests, the permeation coefficient was estimated to be less than 5.1×10 -15 m 2 /s. The potential performance of a HDPE geomembrane and geosynthetic clay liner (GCL) as parts of a composite liner in containing MWCNTs was modelled for six different scenarios. The results suggest that the low value of permeation coefficient of an HDPE geomembrane makes it an effective diffusive barrier for MWCNTs and by keeping the geomembrane defects to minimum during the construction (e.g., number of holes and length of wrinkles) a composite liner commonly used in municipal solid waste landfills will effectively contain MWCNTs.

Effect of Reinforcement Shape and Fiber Treatment on the Mechanical Properties of Oil Palm Empty Fruit Bunch-Polyethylene Composites

International Nuclear Information System (INIS)

Arif, M. F.; Yusoff, P. S. M. M.; Eng, K. K.

2010-01-01

High Density Polyethylene (HDPE) composites were fabricated using oil palm empty fruit bunch (EFB) as the reinforcing material. The effect of reinforcement shape on the tensile and flexural properties, that is 5 mm average length of short fiber and 325-400 μm size distribution of particulate filler have been studied. Overall, EFB short fiber-HDPE composites yield higher mechanical properties compared to EFB particulate-HDPE composites. For both types of composites, considerable improvement showed in tensile and flexural modulus. However, the tensile strength decreased with increase in EFB content. Attempts to improve these properties using alkali and two types of silane, namely γ-Methacryloxypropyltrimethoxysilane (MTS) and vinyltriethoxysilane (VTS) were described. It is found that both types of silane enhanced the mechanical properties of composites. MTS showed better tensile strength compared to VTS. However, only marginal improvement obtained from alkali treatments.

Effect of Reinforcement Shape and Fiber Treatment on the Mechanical Properties of Oil Palm Empty Fruit Bunch-Polyethylene Composites

Science.gov (United States)

Arif, M. F.; Yusoff, P. S. M. M.; Eng, K. K.

2010-03-01

High Density Polyethylene (HDPE) composites were fabricated using oil palm empty fruit bunch (EFB) as the reinforcing material. The effect of reinforcement shape on the tensile and flexural properties, that is 5 mm average length of short fiber and 325-400 μm size distribution of particulate filler have been studied. Overall, EFB short fiber-HDPE composites yield higher mechanical properties compared to EFB particulate-HDPE composites. For both types of composites, considerable improvement showed in tensile and flexural modulus. However, the tensile strength decreased with increase in EFB content. Attempts to improve these properties using alkali and two types of silane, namely γ-Methacryloxypropyltrimethoxysilane (MTS) and vinyltriethoxysilane (VTS) were described. It is found that both types of silane enhanced the mechanical properties of composites. MTS showed better tensile strength compared to VTS. However, only marginal improvement obtained from alkali treatments.

Nanocomposites of high-density polyethylene with amorphous calcium phosphate: in vitro biomineralization and cytocompatibility of human mesenchymal stem cells

International Nuclear Information System (INIS)

Hild, Nora; Fuhrer, Roland; Mohn, Dirk; Bubenhofer, Stephanie B; Grass, Robert N; Luechinger, Norman A; Stark, Wendelin J; Feldman, Kirill; Dora, Claudio

2012-01-01

Polyethylene is widely used as a component of implants in medicine. Composites made of high-density polyethylene (HDPE) containing different amounts of amorphous calcium phosphate nanoparticles were investigated concerning their in vitro biomedical performance. The nanoparticles were produced by flame spray synthesis and extruded with HDPE, the latter complying with Food and Drug Administration regulations. Mechanical properties such as Young's modulus and contact angle as well as in vitro biomineralization of the nanocomposites hot-pressed into thin films were evaluated. The deposition of a hydroxyapatite layer occurred upon immersion in simulated body fluid. Additionally, a cell culture study with human mesenchymal stem cells for six weeks allowed a primary assessment of the cytocompatibility. Viability assays (alamarBlue and lactate dehydrogenase detection) proved the absence of cytotoxic effects of the scaffolds. Microscopic images after hematoxylin and eosin staining confirmed typical growth and morphology. A preliminary experiment analyzed the alkaline phosphatase activity after two weeks. These findings motivate further investigations on bioactive HDPE in bone tissue engineering. (paper)

Nanocomposites of high-density polyethylene with amorphous calcium phosphate: in vitro biomineralization and cytocompatibility of human mesenchymal stem cells.

Science.gov (United States)

Hild, Nora; Fuhrer, Roland; Mohn, Dirk; Bubenhofer, Stephanie B; Grass, Robert N; Luechinger, Norman A; Feldman, Kirill; Dora, Claudio; Stark, Wendelin J

2012-10-01

Polyethylene is widely used as a component of implants in medicine. Composites made of high-density polyethylene (HDPE) containing different amounts of amorphous calcium phosphate nanoparticles were investigated concerning their in vitro biomedical performance. The nanoparticles were produced by flame spray synthesis and extruded with HDPE, the latter complying with Food and Drug Administration regulations. Mechanical properties such as Young's modulus and contact angle as well as in vitro biomineralization of the nanocomposites hot-pressed into thin films were evaluated. The deposition of a hydroxyapatite layer occurred upon immersion in simulated body fluid. Additionally, a cell culture study with human mesenchymal stem cells for six weeks allowed a primary assessment of the cytocompatibility. Viability assays (alamarBlue and lactate dehydrogenase detection) proved the absence of cytotoxic effects of the scaffolds. Microscopic images after hematoxylin and eosin staining confirmed typical growth and morphology. A preliminary experiment analyzed the alkaline phosphatase activity after two weeks. These findings motivate further investigations on bioactive HDPE in bone tissue engineering.

Degradation of low-density polyethylene in the presence of water and deuterium oxide

International Nuclear Information System (INIS)

Sedgwick, R.D.; Al-Sultan, Y.Y.; Abushihada, A.M.

1981-01-01

The degradation of low-density polyethylene in the presence of water as the degradative agent was studied at a temperature of 450 0 C and a pressure greater than 160 atm. The experimental work was conducted in an autoclave of 333-mL capacity. The results indicate the presence of paraffins, olefines, dienes, and aromatics in the degradation products. The occurrence of aromatics in the products demonstrates the importance of this degradation procedure for obtaining these valuable materials. The present work (Part 1) is believed to be the first publication to discuss the production of aromatics from polyethylenes degradation

Elastomer modified polypropylene–polyethylene blends as matrices for wood flour–plastic composites

Science.gov (United States)

Craig Clemons

2010-01-01

Blends of polyethylene (PE) and polypropylene (PP) could potentially be used as matrices for wood–plastic composites (WPCs). The mechanical performance and morphology of both the unfilled blends and wood-filled composites with various elastomers and coupling agents were investigated. Blending of the plastics resulted in either small domains of the minor phase in a...

Preparation, structure and properties of uniaxially oriented polyethylene-silver nanocomposites

NARCIS (Netherlands)

Dirix, Y.J.L.; Bastiaansen, C.W.M.; Caseri, W.R.; Smith, P.

1999-01-01

Uniaxially oriented composites of high-density polyethylene and silver nanoparticles were prepared using solution-casting, melt-extrusion and solid-state drawing techniques. The absorption spectrum in the visible wavelength range of the drawn nanocomposites was observed to strongly depend on the

Electrical conductivity of the «polyethylene — vanadium dioxide» composite

Directory of Open Access Journals (Sweden)

Antonova E. V.

2013-06-01

Full Text Available Samples of the «polyethylene — VO2» composite have been obtained using technologies for manufacturing self-healing polyswitch fuses. The volume fraction of vanadium dioxide in the samples ranged from 0,25 to 0,6. It is shown that the electrical conductivity of the composite is of percolation character. The paper presents research results of the microstructure, the resistance temperature dependence and current-voltage characteristics of polymer composite samples, as well as the impact of the VO2 content on the samples.

Solid-phase photocatalytic degradation of polyethylene-goethite composite film under UV-light irradiation

International Nuclear Information System (INIS)

Liu, G.L.; Zhu, D.W.; Liao, S.J.; Ren, L.Y.; Cui, J.Z.; Zhou, W.B.

2009-01-01

A novel photodegradable polyethylene-goethite (PE-goethite) composite film was prepared by embedding the goethite into the commercial polyethylene. The degradation of PE-goethite composite films was investigated under ultraviolet light irradiation. The photodegradation activity of the PE plastic was determined by monitoring its weight loss, scanning electron microscopic (SEM) analysis and FT-IR spectroscopy. The weight of PE-goethite (1 wt%) sample steadily decreased and led to the total 16% reduction in 300 h under UV-light intensity for 1 mW/cm 2 . Through SEM observation there were some cavities around the goethite powder in the composite films, but there were few changes except some surface chalking phenomenon in pure PE film. The degradation rate could be controlled by changing the concentration of goethite particles in PE plastic. The degradation of composite plastic initiated on PE-goethite interface and then extended into polymer matrix induced by the diffusion of the reactive oxygen species generated on goethite particle surface. The photocatalytic degradation mechanism of the composite films was briefly discussed.

The influence of modification of elastomer compositions in polyethylene oxides on their resistance to mineral oils

Directory of Open Access Journals (Sweden)

E. P. Uss

2017-01-01

Full Text Available The influence of modifying of elastomer compositions based on nitrile rubber in the medium of low molecular weight polyethylene oxide on resistance of rubbers to liquid aggressive mediawas studied. Standard hydrocarbon oils – oil ASTM №1 and ASTM №3, having a constant chemical composition and properties, were used as aggressive fluids. Resistance of elastomer compositions to standard oil was evaluated by change in weight, volume and relative compression set after keeping the samples in these oils at elevated temperatures. The influence of aggressive environment on the degree of swelling and the value of compression set of compositions modified in polyethylene oxides medium was established. It has been shown that the mass/volume of modified rubbers during aging in oil ASTM №1 reduced to a lesser degree compared to unmodified samples, which is probably due to the influence of low molecular weight polyethylene oxides for the formation of vulcanizates structure. At the same time exposure to oil ASTM №3 of elastomer compositions increases the degree of swelling of modified rubber more than unmodified, which can be due to destruction by the action of aggressive medium additional intermolecular bonds between macromolecules of polyethylene oxide and rubber, resulting in increased flexibility of the elastomeric matrix segments. It revealed that modification of rubbers in low molecular weightpolyethylene oxides facilitates preparation of rubber with low compression set after aging in standard oils at elevated temperatures.

Surface modification of polyethylene by diffuse barrier discharge plasma

Czech Academy of Sciences Publication Activity Database

Novák, I.; Števiar, M.; Popelka, A.; Chodák, I.; Mosnáček, J.; Špírková, Milena; Janigová, I.; Kleinová, A.; Sedliačik, J.; Šlouf, Miroslav

2013-01-01

Roč. 53, č. 3 (2013), s. 516-523 ISSN 0032-3888 R&D Projects: GA AV ČR(CZ) IAAX08240901 Institutional research plan: CEZ:AV0Z40500505 Keywords : low-density polyethylene * plasma discharge * surface modification Subject RIV: JI - Composite Materials Impact factor: 1.441, year: 2013

Development of antifungal films based on low-density polyethylene and thyme oil for avocado packaging

CSIR Research Space (South Africa)

Kesavan Pillai, Sreejarani

2015-10-01

Full Text Available Trilayer low-density polyethylene (LDPE) films were prepared by incorporating varying concentrations of thyme oil, as the antifungal active additive for avocado packaging. A comprehensive thermal, structural, mechanical, and functional...

Effects of welding parameters on friction stir spot welding of high density polyethylene sheets

International Nuclear Information System (INIS)

Bilici, Mustafa Kemal; Yukler, Ahmet Irfan

2012-01-01

Graphical abstract: (a) Schematic illustration of the cross section of a friction stir spot weld and (b) Geometry of the weld bonded area, x: nugget thickness and y: the thickness of the upper sheet. Highlights: → Welding parameters affect the FSSW nugget formation and the strength of the joint. → Melting of polyethylene occurred in the vicinity of the tool pin. → The joint that fractures with a pull nugget failure mode has a higher strength. -- Abstract: Friction stir spot welding parameters affect the weld strength of thermoplastics, such as high density polyethylene (HDPE) sheets. The effects of the welding parameters on static strength of friction stir spot welds of high density polyethylene sheets were investigated. For maximizing the weld strength, the selection of welding parameters is very important. In lap-shear tests two fracture modes were observed; cross nugget failure and pull nugget failure. The tool rotational speed, tool plunge depth and dwell time were determined to be important in the joint formation and its strength. The joint which had a better strength fails with a pull nugget failure morphology. Weld cross section image analysis of the joints were done with a video spectral comparator. The plunge rate of the tool was determined to have a negligible effect on friction stir spot welding.

Rheological characterization of LDPE{sub Al} (low density polyethylene and aluminum) e HDPE (high density polyethylene); Caracterizacao das propriedades reologicas da mistura LDPE{sub Al} (polietileno de baixa densidade e aluminio) e HDPE (polietileno de alta densidade)

Energy Technology Data Exchange (ETDEWEB)

Santa Marinha, Ana Beatriz Abreu; Pacheco, Elen Beatriz Acordi Vasques; Monteiro, Elisabeth Ermel da Costa [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Macromoleculas

2008-07-01

The long life packaging contains paper, polyethylene and aluminum for packaging of food. A few part of total amount produced is recycled and another is discharged in landfills in Brazil. The low density polyethylene and aluminum (LDPE{sub Al}) was obtained from recycling this packaging. The rheological properties of the blends were intermediate to ones of the pure polymers. In a general way, the rheological properties were not modified by the aluminum presence. (author)

Poly(ethylene glycol)/carbon quantum dot composite solid films exhibiting intense and tunable blue–red emission

International Nuclear Information System (INIS)

Hao, Yanling; Gan, Zhixing; Xu, Jiaqing; Wu, Xinglong; Chu, Paul K.

2014-01-01

Highlights: • Poly(ethylene glycol)/carbon quantum dots (PEG/CQDs) composite solid films exhibiting strong and tunable blue–red emission were prepared. Successful preparation of tunable emitting CQDs solid films can extend the application of carbon quantum dots in photoelectric devices. • The mechanism of the tunable emission from the PEG/CQDs composite solid films was discussed. • On the basis of the characteristics of the PL from solid films in this work, the complex PL origins of CQDs were further defined. The PL mechanism provides insights into the fluorescence mechanism of CQDs and may promotes their applications. • Poly(ethylene glycol); carbon quantum dots; Strong and tunable blue-red emission; The fluorescent quantum yield of 12.6%. - Abstract: Although carbon quantum dots (CQDs) possess excellent luminescence properties, it is a challenge to apply water-soluble CQDs to tunable luminescent devices. Herein, quaternary CQDs are incorporated into poly(ethylene glycol) to produce poly(ethylene glycol)/CQD composite solid films which exhibit strong and tunable blue–red emission. The fluorescent quantum yield reaches 12.6% which is comparable to that of many liquid CQDs and the photoluminescence characteristics are determined to elucidate the fluorescence mechanism. The CQD solid films with tunable optical properties bode well for photoelectric devices especially displays

Determination of charge carrier mobility in doped low density polyethylene using DC transients

DEFF Research Database (Denmark)

Khalil, M.Salah; Henk, Peter O; Henriksen, Mogens

1989-01-01

Charge carrier mobility was determined for plain and doped low-density polyethylene (LDPE) using DC transient currents. Barium titanate was used as a strongly polar dopant and titanium dioxide as a semiconductor dopant. The values of the mobility obtained were on the order of 10-10 cm2 v-1 s-1...

Performance of water source heat pump system using high-density polyethylene tube heat exchanger wound with square copper wire

Directory of Open Access Journals (Sweden)

Xin Wen Zhang

2015-07-01

Full Text Available Surface water source heat pump system is an energy-efficient heat pump system. Surface water heat exchanger is an important part of heat pump system that can affect the performance of the system. In order to enhance the performance of the system, the overall heat transfer coefficient (U value of the water exchanger using a 32A square copper coiled high-density polyethylene tube was researched. Comparative experiments were conducted between the performance of the coiled high-density polyethylene tube and the 32A smooth high-density polyethylene tube. At the same time, the coefficient of performance of the heat pump was investigated. According to the result, the U value of the coiled tube was 18% higher than that of the smooth tube in natural convection and 19% higher in forced convection. The coefficient of performance of the heat pump with the coiled tube is higher than that with the smooth tube. The economic evaluation of the coiled tube was also investigated.

Evaluation of the radiation resistance of high-density polyethylene

International Nuclear Information System (INIS)

Dougherty, D.R.; Adams, J.W.; Barletta, R.R.

1984-03-01

Mechanical tests following gamma irradiation and creep tests during irradiation have been conducted on high-density polyethylene (HDPE) to provide data to help assess the adequacy of this material for use in high integrity containers (HICs). Two types of HDPE, a highly cross-linked rotationally molded material and a non-cross-linked blow molded material, were used in these tests. Gamma-ray irradiations were performed at several dose rates in environments of air, Barnwell and Hanford backfill soils, and ion-exchange resins. The results of tensile and bend tests on these materials following irradiation are presented along with results on creep during irradiation. 8 references, 9 figures, 2 tables

Flammability of radiation cross-linked low density polyethylene as an insulating material for wire and cable

International Nuclear Information System (INIS)

Basfar, A.A.

2002-01-01

Various formulations of low-density polyethylene blended with ethylene vinyl acetate were prepared to improve the flame retardancy for wire and cable applications. The prepared formulations were cross-linked by γ-rays to 50, 100, 150 and 200 kGy in the presence of trimethylolpropane triacrylate (TMPTA). The effect of thermal aging on mechanical properties of these formulations were investigated. In addition, the influence of various combinations of aluminum trihydroxide and zinc borate as flame retardant fillers on the flammability was explored. Limiting oxygen index (LOI) and average extent of burning were used to characterize the flammability of investigated formulations. An improved flame retardancy of low density polyethylene was achieved by various combinations of flame ratardant fillers and cross-linking by gamma radiation

Improvement of mechanical and thermal properties of high energy electron beam irradiated HDPE/hydroxyapatite nano-composite

Science.gov (United States)

Mohammadi, M.; Ziaie, F.; Majdabadi, A.; Akhavan, A.; Shafaei, M.

2017-01-01

In this research work, the nano-composites of high density polyethylene/hydroxyapatite samples were manufactured via two methods: In the first method, the granules of high density polyethylene and nano-structure hydroxyapatite were processed in an internal mixer to prepare the nano-composite samples with a different weight percentage of the reinforcement phase. As for the second one, high density polyethylene was prepared in nano-powder form in boiling xylene. During this procedure, the hydroxyapatite nano-powder was added with different weight percentages to the solvent to obtain the nano-composite. In both of the procedures, the used hydroxyapatite nano-powder was synthesized via hydrolysis methods. The samples were irradiated under 10 MeV electron beam in 70-200 kGy of doses. Mechanical, thermal and morphological properties of the samples were investigated and compared. The results demonstrate that the nano-composites which we have prepared using nano-polyethylene, show better mechanical and thermal properties than the composites prepared from normal polyethylene granules, due to the better dispersion of nano-particles in the polymer matrix.

Thermal and mechanical properties of injection molded recycled high density polyethylene blends with virgin isotactic polypropylene

International Nuclear Information System (INIS)

Madi, N.K.

2013-01-01

Highlights: ► Recycled high density polyethylene and isotactic polypropylene blends have been prepared by melt compounding. ► Thermal study showed that iPP is not well dispersed into the rHDPE matrix. ► Tensile testing shows that there is strong correlation between the thermal properties and the tensile behavior of rHDPE/ipp blends. - Abstract: Polymer blending has become an important field in polymer research and especially in the area of recycling. In this research the target was to reduce the polymer waste problem. Therefore, recycled high density polyethylene (rHDPE) and virgin isotactic polypropylene (vPP) blends containing upto 30 wt% of vPP have been prepared by melt compounding method using injection molding at 220 °C. The thermal properties, thermal degradation and the mechanical properties of the polymer blends were studied using differential scanning calorimetry (DSC), Thermogravimetric analysis (TGA), and tensile testing method. DSC study shows that in all the blends there are two melting peaks, one around the melting temperature of rHDPE and another one around the melting point of vPP, indicating that vPP is not well dispersed into the rHDPE matrix. The changes in the heat of fusion for the rHDPE/iPP polymer blends versus vPP content suggests that incorporating vPP affects the crystallinity of the system. TGA analysis of the polymer blends shows that parts of rHDPE with 95/5 upto 80/20 of vPP are mostly stable composition which brings about valuable stabilization to the rHDPE. Tensile testing shows that there is strong correlation between the thermal properties and the tensile behavior of rHDPE/vpp blends

IER 203 CED-2 Report: LLNL Final Design for BERP Ball With a Composite Reflector of Thin Polyethylene Backed by Nickel

Energy Technology Data Exchange (ETDEWEB)

Percher, C. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Heinrichs, D. P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kim, S. K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2016-07-18

This report documents the results of final design (CED-2) for IER 203, BERP Ball Composite Reflection, and focuses on critical configurations with a 4.5 kg α-phase plutonium sphere reflected by a combination of thin high-density polyethylene (HDPE) backed by a thick nickel reflector. The Lawrence Livermore National Laboratory’s (LLNL’s) Nuclear Criticality Safety Division, in support of fissile material operations, calculated surprisingly reactive configurations when a fissile core was surrounded by a thin, moderating reflector backed by a thick metal reflector. These composite reflector configurations were much more reactive than either of the single reflector materials separately. The calculated findings have resulted in a stricter-than-anticipated criticality control set, impacting programmatic work. IER 203 was requested in response to these seemingly anomalous calculations to see if the composite reflection effect could be shown experimentally. This report focuses on the Beryllium Reflected Plutonium (BERP) ball as a fissile material core reflected by polyethylene and nickel. A total of four critical configurations were designed as part of CED-2. Fabrication costs are estimated to be $98,500, largely due to the cost of the large nickel reflectors. The IER 203 experiments could reasonably be expected to begin in early FY2017.

Flat-pressed wood plastic composites from sawdust and recycled polyethylene terephthalate (PET): physical and mechanical properties.

Science.gov (United States)

Rahman, Khandkar-Siddikur; Islam, Md Nazrul; Rahman, Md Mushfiqur; Hannan, Md Obaidullah; Dungani, Rudi; Khalil, Hps Abdul

2013-01-01

This study deals with the fabrication of composite matrix from saw dust (SD) and recycled polyethylene terephthalate (PET) at different ratio (w/w) by flat-pressed method. The wood plastic composites (WPCs) were made with a thickness of 6 mm after mixing the saw dust and PET in a rotary type blender followed by flat press process. Physical i.e., density, moisture content (MC), water absorption (WA) and thickness swelling (TS), and mechanical properties i.e., Modulus of Elasticity (MOE) and Modulus of Rupture (MOR) were assessed as a function of mixing ratios according to the ASTM D-1037 standard. WA and TS were measured after 24 hours of immersion in water at 25, 50 and 75°C temperature. It was found that density decreased 18.3% when SD content increased from 40% to 70% into the matix. WA and TS increased when the PET content decreased in the matrix and the testing water temperature increased. MOE and MOR were reached to maximum for the fabricated composites (2008.34 and 27.08 N/mm(2), respectively) when the SD content were only 40%. The results indicated that the fabrication of WPCs from sawdust and PET would technically feasible; however, the use of additives like coupling agents could further enhance the properties of WPCs.

Synthesis of carbon nanostructures from high density polyethylene (HDPE) and polyethylene terephthalate (PET) waste by chemical vapour deposition

Science.gov (United States)

Hatta, M. N. M.; Hashim, M. S.; Hussin, R.; Aida, S.; Kamdi, Z.; Ainuddin, AR; Yunos, MZ

2017-10-01

In this study, carbon nanostructures were synthesized from High Density Polyethylene (HDPE) and Polyethylene terephthalate (PET) waste by single-stage chemical vapour deposition (CVD) method. In CVD, iron was used as catalyst and pyrolitic of carbon source was conducted at temperature 700, 800 and 900°C for 30 minutes. Argon gas was used as carrier gas with flow at 90 sccm. The synthesized carbon nanostructures were characterized by FESEM, EDS and calculation of carbon yield (%). FESEM micrograph shows that the carbon nanostructures were only grown as nanofilament when synthesized from PET waste. The synthesization of carbon nanostructure at 700°C was produced smooth and the smallest diameter nanofilament compared to others. The carbon yield of synthesized carbon nanostructures from PET was lower from HDPE. Furthermore, the carbon yield is recorded to increase with increasing of reaction temperature for all samples. Elemental study by EDS analysis were carried out and the formation of carbon nanostructures was confirmed after CVD process. Utilization of polymer waste to produce carbon nanostructures is beneficial to ensure that the carbon nanotechnology will be sustained in future.

Wax co-cracking synergism of high density polyethylene to alternative fuels

Directory of Open Access Journals (Sweden)

Magdy Motawie

2015-09-01

Full Text Available Attempts have been made to understand the thermal degradation of high density polyethylene (HDPE and their combined co-cracking using different ratios of HDPE and petroleum wax under nitrogen atmosphere. We have conducted the experiments using HDPE as the raw material and petroleum wax as co-feed by at 400 and 450 °C reaction temperatures. The product distribution was noted along with reaction time of 0.5–3 h for the degradation. Thermal gravimetric analysis (TGA technique was used to measure the weight change of the feedstock as a function of temperature and time. Differential scanning calorimetry (DSC was used to determine the degradation temperature. Products were characterized using gas chromatography (GC and infrared spectroscopy (FTIR, some other standard physical methods were used to determine the main properties of the liquid products. Results show that the mixed plastic-wax samples could be converted into gases, gasoline, and middle distillate depending upon the composition of feed polymer/wax ratio. It was found that the products mostly consisted of paraffin and olefin compounds, with carbon numbers of C1–C4, C5–C9 and C10–C19 in the case of gases, gasoline and middle distillate respectively.

Preparation and tensile properties of linear low density polyethylene/rambutan peels (Nephelium chryseum Blum.) flour blends

Science.gov (United States)

Nadhirah, A. Ainatun.; Sam, S. T.; Noriman, N. Z.; Voon, C. H.; Samera, S. S.

2015-05-01

The effect of rambutan peels flour (RPF) content on the tensile properties of linear low density polyethylene filled with rambutan peel flour was studied. RPF was melt blended with linear low-density polyethylene (LLDPE). LLDPE/RPF blends were prepared by using internal mixer (brabender) at 160 °C with the flour content ranged from 0 to 15 wt%. The tensile properties were tested by using a universal testing machine (UTM) according to ASTM D638. The highest tensile strength was observed for pure LLDPE while the tensile strength LLDPE/RPF decreased gradually with the addition of rambutan peels flour content from 0% to 15%. Young's modulus of 63 µm to 250 µm rambutan peels blends with LLDPE with the fiber loading of 0 - 15 wt% increased with increasing fiber loading.

INFLUENCE OF COCONUT SHELL ADDITION ON PHYSICO-MECHANICAL PROPERTIES OF WOOD PLASTIC COMPOSITES1

Directory of Open Access Journals (Sweden)

Éverton Hillig

2018-04-01

Full Text Available ABSTRACT In this study, composites with three types of thermoplastic matrix and cellulosic material in a proportion of 40% were produced. The three thermoplastic matrices were high density polyethylene (HDPE, polypropylene (PP and low density polyethylene (LDPE, and the cellulosic materials were pure wood flour (Pinus taeda L or a mixture of wood flour and coconut shell flour (Cocus nucifera L in equal ratios. The objective was to evaluate the influence of addition of coconut shell on the physico-mechanical properties (density, strength and rigidity and the distribution of the cellulosic material in the thermoplastic matrix of the manufactured composites. It was found that the composites had a satisfactory distribution of wood flour in thermoplastic matrices, but the addition of coconut shell promoted bubble formation in the resulting pieces and, thus, interfered with the material properties. The use of a coupling agent promoted interfacial adhesion (cellulose - thermoplastic matrix, which was better in high density polyethylene composites, followed by polypropylene and low density polyethylene. In general, the coconut shell addition caused a decrease of all properties compared to composites made with Loblolly Pine. In addition, the interactions between thermoplastic type and cellulosic matrix type have been statistically confirmed, which caused variations in the studied properties

Effect of reaction time and polyethylene glycol monooleate-isocyanate composition on the properties of polyurethane-polysiloxane modified epoxy

Science.gov (United States)

Triwulandari, Evi; Ramadhan, Mohammad Kemilau; Ghozali, Muhammad

2017-11-01

Polyurethane-polysiloxane modified epoxy based on polyethylene glycol monooleate (PSME-PEGMO) was synthesized. Polyethylene glycol monooleate (PEGMO) for the synthesis of PSME-GMO was synthesized via esterification between oleic acid and polyethylene glycol by using sodium hydroxide as catalyst. Synthesis of PSME-PEGMO was conducted by reacting epoxy, isocyanate, PEGMO, and polysiloxane (hydrolyzed and condensable 3-glycidyloxypropyltrimethoxysilane) simultaneously in one step. This synthesis was carried out by varied the reaction time (1, 2, 3 hours), PEGMO-isocyanate composition (PI composition: 10 and 20 % toward epoxy), and isocyanate/PEGMO ratio (NCO/OH ratio: 1.5 and 2.5). Characterization of PSME-PEGMO was conducted by determining the isocyanate conversion, viscosity analysis, mechanical properties (tensile strength and elongation at break) and thermal analysis using thermogravimetric analysis (TGA). The data show that the PI composition and NCO/OH ratio does not affect the isocyanate conversion linearly. The viscosity of PSME-PEGMO product at ratio and composition variation show has tended to increase with increasing of reaction time. The highest tensile strength and elongation at break PSME-PEGMO was shown by PI composition 20%, NCO/OH ratio 2.5 and reaction time 3 hours.

Enhancement of in vitro high-density polyethylene (HDPE) degradation by physical, chemical, and biological treatments.

Science.gov (United States)

Balasubramanian, V; Natarajan, K; Rajeshkannan, V; Perumal, P

2014-11-01

Partially degraded high-density polyethylene (HDPE) was collected from plastic waste dump yard for biodegradation using fungi. Of various fungi screened, strain MF12 was found efficient in degrading HDPE by weight loss and Fourier transform infrared (FT-IR) spectrophotometric analysis. Strain MF12 was selected as efficient HDPE degraders for further studies, and their growth medium composition was optimized. Among those different media used, basal minimal medium (BMM) was suitable for the HDPE degradation by strain MF12. Strain MF12 was subjected to 28S rRNA sequence analysis and identified as Aspergillus terreus MF12. HDPE degradation was carried out using combinatorial physical and chemical treatments in conjunction to biological treatment. The high level of HDPE degradation was observed in ultraviolet (UV) and KMnO4/HCl with A. terreus MF12 treatment, i.e., FT10. The abiotic physical and chemical factors enhance the biodegradation of HDPE using A. terreus MF12.

Characteristics of Friction Stir Processed UHMW Polyethylene Based Composite

Science.gov (United States)

Hussain, G.; Khan, I.

2018-01-01

Ultra-high molecular weight polyethylene (UHMWPE) based composites are widely used in biomedical and food industries because of their biocompatibility and enhanced properties. The aim of this study was to fabricate UHMWPE / nHA composite through heat assisted Friction Stir Processing. The rotational speed (ω), feed rate (f), volume fraction of nHA (v) and shoulder temperature (T) were selected as the process parameters. Macroscopic and microscopic analysis revealed that these parameters have significant effects on the distribution of reinforcing material, defects formation and material mixing. Defects were observed especially at low levels of (ω, T) and high levels of (f, v). Low level of v with medium levels of other parameters resulted in better mixing and minimum defects. A 10% increase in strength with only 1% reduction in Percent Elongation was observed at the above set of conditions. Moreover, the resulted hardness of the composite was higher than that of the parent material.

Hybrid composites

CSIR Research Space (South Africa)

Jacob John, Maya

2009-04-01

Full Text Available mixed short sisal/glass hybrid fibre reinforced low density polyethylene composites was investigated by Kalaprasad et al [25].Chemical surface modifications such as alkali, acetic anhydride, stearic acid, permanganate, maleic anhydride, silane...

Effect of Aspergillus versicolor strain JASS1 on low density polyethylene degradation

Science.gov (United States)

Gajendiran, A.; Subramani, S.; Abraham, J.

2017-11-01

Low density polyethylene (LDPE) waste disposal remains one of the major environmental concerns faced by the world today. In past decades, major focus has been given to enhance the biodegradation of LDPE by microbial species. In this present study, Aspergillus versicolor with the ability to degrade LDPE was isolated from municipal landfill area using enrichment technique. Based on 18S rRNA gene sequencing confirmed its identity as Aspergillus versicolor. The biodegradation study was carried out for 90 d in M1 medium. The degradation behaviour of LDPE films by Aspergillus versicolor strain JASS1 were confirmed by weight loss, CO2 evolution, Scanning electron microscopy (SEM) analysis, Atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR) technique. From current investigation, it can be concluded that our isolated strain JASS1 had the potential to degrade LDPE films and it can be useful in solving the problem caused by polyethylene in the environment.

Flexural properties of polyethylene, glass and carbon fiber-reinforced resin composites for prosthetic frameworks.

Science.gov (United States)

Maruo, Yukinori; Nishigawa, Goro; Irie, Masao; Yoshihara, Kumiko; Minagi, Shogo

2015-01-01

High flexural properties are needed for fixed partial denture or implant prosthesis to resist susceptibility to failures caused by occlusal overload. The aim of this investigation was to clarify the effects of four different kinds of fibers on the flexural properties of fiber-reinforced composites. Polyethylene fiber, glass fiber and two types of carbon fibers were used for reinforcement. Seven groups of specimens, 2 × 2 × 25 mm, were prepared (n = 10 per group). Four groups of resin composite specimens were reinforced with polyethylene, glass or one type of carbon fiber. The remaining three groups served as controls, with each group comprising one brand of resin composite without any fiber. After 24-h water storage in 37°C distilled water, the flexural properties of each specimen were examined with static three-point flexural test at a crosshead speed of 0.5 mm/min. Compared to the control without any fiber, glass and carbon fibers significantly increased the flexural strength (p glass fiber (p glass fibers (p > 0.05). Fibers could, therefore, improve the flexural properties of resin composite and carbon fibers in longitudinal form yielded the better effects for reinforcement.

Ultrasonic Characterisation of Epoxy Resin/Polyethylene Terephthalate (PET Char Powder Composites

Directory of Open Access Journals (Sweden)

Imran ORAL

2016-11-01

Full Text Available This study is carried out in order to determine the elastic properties of the Epoxy Resin (ER / Polyethylene terephthalate (PET Char Powder Composites by ultrasonic wave velocity measurement method. Plastic waste was recycled as raw material for the preparation of epoxy composite materials. The supplied chars were mixed with epoxy resin matrix at weight percentages of 10 %, 20 % and 30 % for preparing ER/PET Char Powder (PCP composites. The effect of PET char powder on the elastic properties of ER/PCP composites were investigated by ultrasonic pulse-echo method. According to the obtained results, the composition ratio of 80:20 is the most appropriate composition ratio, which gave the highest elastic constants values for ER/PCP composites. On the other hand, the best electrical conductivity value was obtained for 70:30 composition ratio. It was observed that ultrasonic shear wave velocity correlated more perfectly than any other parameters with hardness.DOI: http://dx.doi.org/10.5755/j01.ms.22.4.12190

Effect of expanded graphite on the phase change materials of high density polyethylene/wax blends

Energy Technology Data Exchange (ETDEWEB)

AlMaadeed, M.A., E-mail: m.alali@qu.edu.qa [Center for Advanced Materials, Qatar University, 2713 Doha (Qatar); Labidi, Sami [Center for Advanced Materials, Qatar University, 2713 Doha (Qatar); Krupa, Igor [QAPCO Polymer Chair, Center for Advanced Materials, Qatar University, P.O. Box 2713, Doha (Qatar); Karkri, Mustapha [Université Paris-Est CERTES, 61 avenue du Général de Gaulle, 94010 Créteil (France)

2015-01-20

Highlights: • Expanded graphite (EG) and low melting point (42.3 °C) wax were added to HDPE to form phase change material. • EG was well dispersed in the composites and did not affect the melting or crystallization of the HDPE matrix. • EG increased the thermal stability of the composites by reducing chain mobility and inhibiting degradation. • The addition of a relatively small quantity of EG enhances the heat conduction in the composite. • HDPE/40% RT42 that contained up to 15% EG demonstrated excellent mechanical and thermal properties and can be used as PCM. - Abstract: Phase change materials fabricated from high density polyethylene (HDPE) blended with 40 or 50 wt% commercial wax (melting point of 43.08 °C) and up to 15 wt% expanded graphite (EG) were studied. Techniques including scanning electron microscope (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and an experimental device to measure diffusivity and conductivity (DICO) were used to determine the microstructural, mechanical and thermal properties of the composites. The composites possessed good mechanical properties. Additionally, no leaching was observed during material processing or characterization. Although the Young’s modulus increased with the addition of EG, no significant changes in tensile strength were detected. The maximum Young’s modulus achieved was 650 MPa for the HDPE/40% wax composite with 15 wt% EG. The EG was well dispersed within the composites and did not affect the melting or crystallization of the HDPE matrix. The incorporation of EG increased the thermal stability of the composites by reducing chain mobility and inhibiting degradation. The intensification of thermal conductivity occurred with increasing fractions of EG, which was attributed to the high thermal conductivity of graphite. The maximum quantity of heat stored by latent heat was found for the HDPE/40% wax composite with EG. The addition of a relatively small quantity

Effect of expanded graphite on the phase change materials of high density polyethylene/wax blends

International Nuclear Information System (INIS)

AlMaadeed, M.A.; Labidi, Sami; Krupa, Igor; Karkri, Mustapha

2015-01-01

Highlights: • Expanded graphite (EG) and low melting point (42.3 °C) wax were added to HDPE to form phase change material. • EG was well dispersed in the composites and did not affect the melting or crystallization of the HDPE matrix. • EG increased the thermal stability of the composites by reducing chain mobility and inhibiting degradation. • The addition of a relatively small quantity of EG enhances the heat conduction in the composite. • HDPE/40% RT42 that contained up to 15% EG demonstrated excellent mechanical and thermal properties and can be used as PCM. - Abstract: Phase change materials fabricated from high density polyethylene (HDPE) blended with 40 or 50 wt% commercial wax (melting point of 43.08 °C) and up to 15 wt% expanded graphite (EG) were studied. Techniques including scanning electron microscope (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and an experimental device to measure diffusivity and conductivity (DICO) were used to determine the microstructural, mechanical and thermal properties of the composites. The composites possessed good mechanical properties. Additionally, no leaching was observed during material processing or characterization. Although the Young’s modulus increased with the addition of EG, no significant changes in tensile strength were detected. The maximum Young’s modulus achieved was 650 MPa for the HDPE/40% wax composite with 15 wt% EG. The EG was well dispersed within the composites and did not affect the melting or crystallization of the HDPE matrix. The incorporation of EG increased the thermal stability of the composites by reducing chain mobility and inhibiting degradation. The intensification of thermal conductivity occurred with increasing fractions of EG, which was attributed to the high thermal conductivity of graphite. The maximum quantity of heat stored by latent heat was found for the HDPE/40% wax composite with EG. The addition of a relatively small quantity

Iridescent cellulose nanocrystal/polyethylene oxide composite films with low coefficient of thermal expansion

Science.gov (United States)

Jairo A. Diaz; Julia L. Braun; Robert J. Moon; Jeffrey P. Youngblood

2015-01-01

Simultaneous control over optical and thermal properties is particularly challenging and highly desired in fields like organic electronics. Here we incorporated cellulose nanocrystals (CNCs) into polyethylene oxide (PEO) in an attempt to preserve the iridescent CNC optical reflection given by their chiral nematic organisation, while reducing the composite thermal...

Effect of low-density polyethylene on smoke emissions from burning of simulated debris piles

Science.gov (United States)

Seyedehsan Hosseini; Qi Li; Manish Shrivastava; David R. Weise; David R. Cocker; J. Wayne Miller; Heejung S Jung

2014-01-01

Low-density polyethylene (LDPE) plastic is used to keep piled debris from silvicultural activities—activities associated with development and care of forests—dry to enable efficient disposal by burning. The effects of inclusion of LDPE in this manner on smoke emissions are not well known. In a combustion laboratory experiment, 2-kg mixtures of LDPE and manzanita (

Catalytic degradation of waste high-density polyethylene into fuel products using BaCO{sub 3} as a catalyst

Energy Technology Data Exchange (ETDEWEB)

Jan, M. Rasul; Shah, Jasmin; Gulab, Hussain [Institute of Chemical Sciences, University of Peshawar, N.W.F.P. (Pakistan)

2010-11-15

Waste high-density polyethylene (HDPE) was degraded thermally and catalytically using BaCO{sub 3} as a catalyst under different conditions of temperature, cat/pol ratio and time. The oil collected at optimum conditions (450 C, 0.1 cat/pol ratio and 2 h reaction time) was fractionated at different temperatures and fuel property of the fractions and parent oil was evaluated by their physicochemical parameters for fuel tests. The results were compared with the standard values for gasoline, kerosene and diesel oil. Boiling point distribution (BPD) curves were plotted from the gas chromatographic study of the samples and compared with that of the standard gasoline, kerosene and diesel. The oil samples were analyzed using GC/MS in order to find out their composition. The physical parameters and the composition of the parent oil and its fractions support the resemblance of the samples with the standard fuel oils. The light fractions best match with gasoline, the middle fractions match with kerosene and the heavier fractions match with diesel oil in almost all of the characteristic properties. (author)

Fluorescence properties of dansyl groups covalently bonded to the surface of oxidatively functionalized low-density polyethylene film

Science.gov (United States)

Holmes-Farley, S. R.; Whitesides, G. M.

1985-12-01

Brief oxidation of low-density polyethylene film with chromic acid in aqueous sulfuric acid introduced carboxylic acid and ketone and/or aldehyde groups onto the surface of the film. The carboxylic acid moieties can be used to attach more complex functionality to the polymer surface. We are developing this surface-functionalized polyethylene (named polyethylene carboxylic acid, PE-CO2H, to emphasize the functional group that dominates its surface properties) as a substrate with which to study problems in organic surface chemistry--especially wetting, polymer surface reconstruction, and adhesion--using physical-organic techniques. This document describes the preparation, characterization, and fluorescence properties of derivatives of PE-CO2H in which the Dansyl (5-dimethylaminonaphthalene-1-sulfonyl) group has been covalently attached by amide links to the surface carbonyl moieties.

Study of effects gamma radiation linear low density polyethylene (LLDPE) injected

International Nuclear Information System (INIS)

Oliveira, Ana Claudia Feitoza de

2014-01-01

The use of package sterilization through gamma radiation aim to reduce the microbiological contamination. The linear low density polyethylene (LLDPE) can be obtained by a process in solution, suspension or gaseous phase, depending on the type of the catalyzer used, that can be heterogeneous, or homogeneous, or metallocenes Ziegler-Natta. According to the literature, the gamma radiation presents a high penetration at polymeric materials causing the appearing of scissions, reticulation, and degradation when oxygen presence. This paper were irradiated with 60 Co with 2000 kCi of activity, in presence of air, samples of LLDPE injected. Utilized doses of 5, 10, 20, 50 or 100 kGy, and about 5 kGy.h -1 dose rates, at room temperature. After irradiation, the samples were heated for 60 min at 100 deg C to promote recombination and annihilation of residual radicals. For characterization of PEBLD were used methods; Melt flow index, swelling, gel fraction, Fourier Transform Infrared (FTIR), Differential Scanning Calorimetry (DSC), X-Ray Diffraction (DRX), Thermogravimetric Analysis (TG), Dynamic Mechanical Analysis (DMA), rheological measurements, Scanning Electronic Microscopy and mechanical tests to identify the effects or gamma radiation in polyethylene. (author)

COMPOSITE POLYMERICADDITIVESDESIGNATED FORCONCRETEMIXES BASED ONPOLYACRYLATES, PRODUCTS OF THERMAL DECOMPOSITION OF POLYAMIDE-6 AND LOW-MOLECULAR POLYETHYLENE

Directory of Open Access Journals (Sweden)

Polyakov Vyacheslav Sergeevich

2012-07-01

4 the optimal composite additive that increases the time period of stiffening of the cement grout , improves the water resistance and the compressive strength of concrete, represents the composition of polyacrylates and polymethacrylates, products of thermal decomposition of polyamide-6 and low-molecular polyethylene in the weight ratio of 1:1:0.5.

Plasma Treatment of Agave Fiber Powder and Its Effect on the Mechanical and Thermal Properties of Composites Based on Polyethylene

Directory of Open Access Journals (Sweden)

Florentino Soriano Corral

2016-01-01

Full Text Available Composites based on low-density polyethylene (LDPE were prepared with Agave fiber powder (AFP that was coated by plasma polymerization process using ethylene gas. Treated and pristine AFP were analyzed by infrared spectroscopy, scanning electron microscopy, and contact water angle for the assessment of surface properties. The polymer composites were prepared by melt mixing using 0, 5, 10, and 20 wt% of AFP and their mechanical and thermal properties were measured. Dispersion evaluation in water confirmed that the AFP treated changed from hydrophilic to hydrophobic behavior and it was also corroborated with water contact angle tests. The addition of treated and untreated AFP (200 mesh at 20 wt% promotes an increase of Young’s modulus of the composites of up to 60% and 32%, respectively, in relation to the neat matrix. Also, an increase of crystallinity of LDPE was observed by the addition of treated and untreated AFP; however no significant effect on the crystallization temperature was observed in LDPE containing AFP.

A Nanotechnology Approach to Lightweight Multifunctional Polyethylene Composite Materials for Use Against the Space Environment, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Polyethylene-based composite materials are under consideration as multifunctional structural materials, with the expectation that they can provide radiation...

The Effect of wheat straw particle size on the mechanical and water absorption properties of wheat straw/low density polyethylene biocomposites for packaging applications

Directory of Open Access Journals (Sweden)

Behjat Tajeddin

2017-08-01

Full Text Available Natural composites with biodegradability properties can be used as a renewable alternative to replacing conventional plastics. Thus, to reduce the plastics applications in the packaging industry, biocomposites content of wheat straw (with 40, 100, 140 mesh as a natural biodegradable composite and low density polyethylene (LDPE as a common synthetic polymer in the packaging industry were prepared and characterized by the mechanical and water absorption properties. Polyethylene-graft-maleic anhydride was used as a compatibilizer material. Morphology of wheat straw flour was studied by optical microscope to obtain the aspect ratio (L/D. The tensile and flexural tests were applied for determining mechanical properties and scanning electron microscope (SEM was used for particles distribution and sample structures. The water absorption of the samples was calculated by weight difference. The results indicated that the particle size of wheat straw four and the L/D amount are Significantly affected on the tensile strength and water absorption of the samples. However, the effect of wheat sraw particle size on the flexural strength was not significant. Overall conclusions show that by increasing the particle size of the filler (wheat straw, can prepare the biocomposite with better tensile strength and less water absorption compared with smaller particle size.

Physical properties of drawn very low density polyethylene films

Energy Technology Data Exchange (ETDEWEB)

Kim, B.S. [Yeungnam University, Kyongsan (Korea, Republic of); Lee, J.Y. [Korea Institute of Footwear and Leather Technology, Pusan (Korea, Republic of)

1998-05-01

Very low density polyethylene (VLDPE) films were prepared by quenching the pressed melt in ice water. The films were drawn with universal testing machine under constant temperature at four different temperatures, 30, 60, 80, and 110 {sup o} C. Thermal, mechanical properties, grossity, and gas permeability of the drawn VLDPE films as a function of draw ratio were investigated to examine their applicability to packaging. The films showed tow melting peaks, i.e., low temperature endotherm (LTE) and high temperature endotherm (HTE). The melting temperatures were increased with the draw ratio and the drawing temperature. The mechanical properties of the VLDPE film drawn at 80 {sup o} C were superior to those drawn at 110 {sup o} C. The grossity and gas permeability of the VLDPE film drawn at 110 {sup o} C were found to be best among the drawn films.

Assessment of the Resistance to External Factors of Low-Density Polyethylene Modified with Natural Fillers

Directory of Open Access Journals (Sweden)

Karolina Głogowska

2017-12-01

Full Text Available The study reports the results of investigation of basic processing and thermal properties of low-density polyethylene modified with two types of natural filler: wheat bran and pumpkin seed hulls, their content ranging from 5% to 15% relative to the matrix. In addition, the physical properties of the produced granulates are determined, i.e. the relationship between their density and the applied contents of the tested fillers. Furthermore, the study reports the results concerning the longitudinal shrinkage, abrasion resistance and cold water absorption of injection molded tensile specimens.

LDPE/HDPE/Clay Nano composites: Effects of Compatibilizer on the Structure and Dielectric Response

International Nuclear Information System (INIS)

David, Z.E.; Ngo, A.D.

2013-01-01

PE/clay nano composites were prepared by mixing a commercially available premixed polyethylene/O-MMT master batch into a polyethylene blend matrix containing 80 wt% low-density polyethylene and 20 wt% high-density polyethylene with and without anhydride modified polyethylene (PE-MA) as the compatibilizer using a corotating twin-screw extruder. In this study, the effect of nano clay and compatibilizer on the structure and dielectric response of PE/clay nano composites has been investigated. The microstructure of PE/clay nano composites was characterized using wide-angle X-ray diffraction (WAXD) and a scanning electron microscope (SEM). Thermal properties were examined using differential scanning calorimetry (DSC). The dielectric response of neat PE was compared with that of PE/clay nano composite with and without the compatibilizer. The XRD and SEM results showed that the PE/O-MMT nano composite with the PE-MA compatibilizer was better dispersed. In the nano composite materials, two relaxation modes are detected in the dielectric losses. The first relaxation is due to a Maxwell-Wagner-Sillars interfacial polarization, and the second relaxation can be related to dipolar polarization. A relationship between the degree of dispersion and the relaxation rate f m ax of Maxwell-Wagner-Sillars was found and discussed.

Wine evolution and spatial distribution of oxygen during storage in high-density polyethylene tanks.

Science.gov (United States)

del Alamo-Sanza, María; Laurie, V Felipe; Nevares, Ignacio

2015-04-01

Porous plastic tanks are permeable to oxygen due to the nature of the polymers with which they are manufactured. In the wine industry, these types of tanks are used mainly for storing wine surpluses. Lately, their use in combination with oak pieces has also been proposed as an alternative to mimic traditional barrel ageing. In this study, the spatial distribution of dissolved oxygen in a wine-like model solution, and the oxygen transfer rate (OTR) of high-density polyethylene tanks (HDPE), was analysed by means of a non-invasive opto-luminescence detector. Also, the chemical and sensory evolution of red wine, treated with oak pieces, and stored in HDPE tanks was examined and compared against traditional oak barrel ageing. The average OTR calculated for these tanks was within the commonly accepted amounts reported for new barrels. With regards to wine evolution, a number of compositional and sensory differences were observed between the wines aged in oak barrels and those stored in HDPE tanks with oak barrel alternatives. The use of HDPE tanks in combination with oak wood alternatives is a viable alternative too for ageing wine. © 2014 Society of Chemical Industry.

Ballistic behavior of ultra-high molecular weight polyethylene composite: effect of gamma radiation

International Nuclear Information System (INIS)

Alves, Andreia L. dos Santos; Nascimento, Lucio F.C.; Suarez, Joao C. Miguez; lucio2002bol.com.br

2003-01-01

Since World War II, textile composites have been used as ballistic armor. Ultra-high molecular weight polyethylene (UHMWPE) fibers are used in the production of armor materials. As they have been developed and commercialized only recently, there is not enough information about the effect of environmental agents in the ballistic performance of UHMWPE composites. In the present work, was evaluated the ballistic behavior of composite plates manufactured with UHMWPE fibers after exposure to gamma radiation. The ballistic tests results were related to the macromolecular alterations induced by the radiation through mechanical (hardness, impact and flexure) and physicochemical (Ftir/Mir. DSC and TGA) testing. It was observed that irradiation induces changes in the UHMWPE, degrading the ballistic performance of the composite. These results are presented and discussed. (author)

Effect of fiber geometry on macroscale friction of ordered low-density polyethylene nanofiber arrays.

Science.gov (United States)

Lee, Dae Ho; Kim, Yongkwan; Fearing, Ronald S; Maboudian, Roya

2011-09-06

Ordered low-density polyethylene (LDPE) nanofiber arrays are fabricated from silicon nanowire (SiNW) templates synthesized by a simple wet-chemical process based on metal-assisted electroless etching combined with colloidal lithography. The geometrical effect of nanofibrillar structures on their macroscale friction is investigated over a wide range of diameters and lengths under the same fiber density. The optimum geometry for contacting a smooth glass surface is presented with discussions on the compromise between fiber tip-contact area and fiber compliance. A friction design map is developed, which shows that the theoretical optimum design condition agrees well with the LDPE nanofiber geometries exhibiting high measured friction. © 2011 American Chemical Society

Leak detection in medium density polyethylene (MDPE) pipe using pressure transient method

Science.gov (United States)

Amin, M. M.; Ghazali, M. F.; PiRemli, M. A.; Hamat, A. M. A.; Adnan, N. F.

2015-12-01

Water is an essential part of commodity for a daily life usage for an average person, from personal uses such as residential or commercial consumers to industries utilization. This study emphasizes on detection of leaking in medium density polyethylene (MDPE) pipe using pressure transient method. This type of pipe is used to analyze the position of the leakage in the pipeline by using Ensemble Empirical Mode Decomposition Method (EEMD) with signal masking. Water hammer would induce an impulse throughout the pipeline that caused the system turns into a surge of water wave. Thus, solenoid valve is used to create a water hammer through the pipelines. The data from the pressure sensor is collected using DASYLab software. The data analysis of the pressure signal will be decomposed into a series of wave composition using EEMD signal masking method in matrix laboratory (MATLAB) software. The series of decomposition of signals is then carefully selected which reflected intrinsic mode function (IMF). These IMFs will be displayed by using a mathematical algorithm, known as Hilbert transform (HT) spectrum. The IMF signal was analysed to capture the differences. The analyzed data is compared with the actual measurement of the leakage in term of percentage error. The error recorded is below than 1% and it is proved that this method highly reliable and accurate for leak detection.

Characteristics of heat shrinkable high density polyethylene crosslinked by γ-irradiation

International Nuclear Information System (INIS)

Kang, Phil Hyun; Nho, Young Chang

2001-01-01

The effects of γ-irradiation on the crosslinking of high density polyethylene (HDPE) was investigated for the purpose of obtaining a suitable formulation for heat shrinkable materials. In this study the HDPE specimens were prepared by blending with cross linking agents and pressed into a 0.2 mm sheet at 180 .deg. C. γ-irradiation was conducted at 40 to 100 kGy in nitrogen. The heat shrinkable property and thermal mechanical property of the HDPE sheets have been investigated. It was found that the degree of crosslinking of the irradiated HDPE samples were increased with irradiation dose. Compared with the HDPE containing triallylisocyanurate, the HDPE containing trimethlol propane triacrylate shows a slight increase in crosslinking density. The heat transformation and dimension change of HDPE decreased with increasing radiation dose. The heat shrinkage of the samples increased with increasing annealing temperatures. The thermal resistance of HDPE increased upon the crosslinking of HDPE

Amperometric Biosensor Based on Zirconium Oxide/Polyethylene Glycol/Tyrosinase Composite Film for the Detection of Phenolic Compounds.

Science.gov (United States)

Ahmad, Nor Monica; Abdullah, Jaafar; Yusof, Nor Azah; Ab Rashid, Ahmad Hazri; Abd Rahman, Samsulida; Hasan, Md Rakibul

2016-06-29

A phenolic biosensor based on a zirconium oxide/polyethylene glycol/tyrosinase composite film for the detection of phenolic compounds has been explored. The formation of the composite film was expected via electrostatic interaction between hexacetyltrimethylammonium bromide (CTAB), polyethylene glycol (PEG), and zirconium oxide nanoparticles casted on screen printed carbon electrode (SPCE). Herein, the electrode was treated by casting hexacetyltrimethylammonium bromide on SPCE to promote a positively charged surface. Later, zirconium oxide was mixed with polyethylene glycol and the mixture was dropped cast onto the positively charged SPCE/CTAB. Tyrosinase was further immobilized onto the modified SPCE. Characterization of the prepared nanocomposite film and the modified SPCE surface was investigated by scanning electron microscopy (SEM), Electrochemical Impedance Spectroscopy (EIS), and Cyclic voltamogram (CV). The developed biosensor exhibits rapid response for less than 10 s. Two linear calibration curves towards phenol in the concentrations ranges of 0.075-10 µM and 10-55 µM with the detection limit of 0.034 µM were obtained. The biosensor shows high sensitivity and good storage stability for at least 30 days.

Investigating the mechanical and barrier properties to oxygen and fuel of high density polyethylene–graphene nanoplatelet composites

Energy Technology Data Exchange (ETDEWEB)

Honaker, K., E-mail: honakers@egr.msu.edu; Vautard, F.; Drzal, L.T.

2017-02-15

Highlights: • Melt mixing used to investigate high density polyethylene and graphene nanoplatelet composite. • Addition of graphene nanoplatelets resulted in a stiffer polymer matrix. • Presence of graphene nanoplatelets causes a decrease in oxygen and fuel permeation. - Abstract: Graphene nanoplatelets (GnP) of different sizes were investigated for their ability to modify high density polyethylene (HDPE) for potential fuel system applications, focusing on compounding via melt mixing in a twin-screw extruder. Mechanical properties, crystallinity of the polymer, and permeation to oxygen and fuel were assessed as a function of GnP concentration. The surface of GnP acted as a nucleation site for the generation of HDPE crystallites, increasing the crystallinity. The flexural properties were improved, clearly influenced by platelet size and quality of dispersion. A sharp, 46% decrease of the impact resistance was observed, even at low GnP concentration (0.2 wt.%). With a 15 wt.% GnP-M-15 (platelets with a 15 μm diameter), a 73% reduction in oxygen permeation was observed and a 74% reduction in fuel vapor transmission. This correlation was similar throughout the GnP concentration range. The smaller diameter platelets had a lesser effect on the properties.

Influence of food matrix on absorption of flavour compounds by linear low-density polyethylene: proteins and carbohydrates

NARCIS (Netherlands)

Willige, van R.W.G.; Linssen, J.P.H.; Voragen, A.G.J.

2000-01-01

The influence of oil and food components in real food products on the absorption of four flavour compounds (limonene, decanal, linalool and ethyl 2-methyl butyrate) into linear low-density polyethylene (LLDPE) was studied using a large volume injection GC in vial extraction method. Model food

THE EFFECT OF DIAMETER ON THE MECHANICAL-PROPERTIES OF AMORPHOUS-CARBON FIBERS FROM LINEAR LOW-DENSITY POLYETHYLENE

NARCIS (Netherlands)

PENNING, JP; LAGCHER, R; PENNINGS, AJ

The mechanical properties of amorphous carbon fibers, derived from linear low density polyethylene strongly depend on the fibre diameter, which may be attributed to the presence of a skin/core structure in these fibres. High strength carbon fibres could thus be prepared by using thin precursor

Rheo-optical Raman study of microscopic deformation in high-density polyethylene under hot drawing

OpenAIRE

Kida, Takumitsu; Hiejima, Yusuke; Nitta, Koh-hei

2015-01-01

In situ observation of the microscopic structural changes in high-density polyethylene during hot drawing was performed by incorporating a temperature-controlled tensile machine into a Raman spectroscopy apparatus. It was found that the load sharing and molecular orientation during elongation drastically changed at 50°C. The microscopic stress of the crystalline chains decreased with increasing temperature and diminished around 50°C. Moreover, the orientation of the crystalline chains was gre...

A study of the barrier properties of polyethylene coated with a nanocellulose/magnetite composite film

Directory of Open Access Journals (Sweden)

Đorđević Nenad

2016-01-01

Full Text Available The morphological, thermal and barrier properties of low-density polyethylene/polycaprolactone-modified nanocellulose hybrid materials were investigated in this paper. Nanonocelulose/magnetite (NC-Fe3O4 nanocomposite and maleic acid functionalized NC/magnetite (NCMA-Fe3O4 nanocomposite were prepared and used as filler at various concentrations (5, 10 and 15 wt. % in polycaprolactone (PCL layer. PE was coated with PCL/NC/magnetite layer. The addition of the filler did not unfavorably affect the inherent properties of the polymer, especially its barrier properties. Oxygen permeation measurements show that the oxygen barrier properties of magnetite enriched PCL film were improved due to chemical activity of added material. The highest level of barrier capacity was observed for PE samples coated with PCL based composite with NCMA-Fe3O4 micro/-nanofiller, which implies the significant contribution of nanocellulose surface modification with maleic anhydride residue to improved barrier properties. [Projekat Ministarstva nauke Republike Srbije, br. III45019 i br. OI172013

Polyethylene/hydrophilic polymer blends for biomedical applications.

Science.gov (United States)

Brynda, E; Houska, M; Novikova, S P; Dobrova, N B

1987-01-01

Polyethylene blends with poly(2-hydroxyethyl methacrylate) [poly(HEMA)] or poly(2,3-dihydroxypropyl methacrylate) [poly(DHPMA)] were prepared by swelling polyethylene with HEMA or 2,3-epoxypropyl methacrylate (EPMA) and by polymerization of the respective monomers. Poly(EPMA) in blends was hydrolysed to poly(DHPMA) with acetic acid. The blends had similar surface and bulk compositions. Swelling with water and surface wettability were proportional to the content of the hydrophilic component; at the same content the polyethylene/poly(DHPMA) blends appeared more hydrophilic than those of polyethylene/poly(HEMA). Thrombus formation in contact with blood examined ex vivo and in vivo was considerably slower on the blends than on unmodified polyethylene. The tests indicated optima in composition; the best biological response was achieved with the blends containing about 14% poly(HEMA) or 16% poly(DHPMA).

Preparation and performance of novel polyvinylpyrrolidone/polyethylene glycol phase change materials composite fibers by centrifugal spinning

Science.gov (United States)

Zhang, Xiaoguang; Qiao, Jiaxin; Zhao, Hang; Huang, Zhaohui; Liu, Yangai; Fang, Minghao; Wu, Xiaowen; Min, Xin

2018-01-01

Currently, phase change materials (PCMs) composite fibers are typically prepared by electrospinning. However, electrospinning exhibits safety concerns and a low production rate, which limit its practical applications as a cost-effective fiber fabrication approach. Therefore, a novel, and simple centrifugal spinning technology is employed to extrude fibers from composite solutions using a high-speed rotary and perforated spinneret. The composite fibers based on polyvinylpyrrolidone (PVP) and polyethylene glycol (PEG) were prepared by centrifugal spinning. The SEM of PVP/PEG composite fibers indicated that the fibrous morphology is well preserved. The DSC and TGA indicated that PVP/PEG composite fibers exhibit good thermal properties.

High-density polyethylene (HDPE)-degrading potential bacteria from marine ecosystem of Gulf of Mannar, India.

Science.gov (United States)

Balasubramanian, V; Natarajan, K; Hemambika, B; Ramesh, N; Sumathi, C S; Kottaimuthu, R; Rajesh Kannan, V

2010-08-01

Assessment of high-density polyethylene (HDPE)-degrading bacteria isolated from plastic waste dumpsites of Gulf of Mannar. Rationally, 15 bacteria (GMB1-GMB15) were isolated by enrichment technique. GMB5 and GMB7 were selected for further studies based on their efficiency to degrade the HDPE and identified as Arthrobacter sp. and Pseudomonas sp., respectively. Assessed weight loss of HDPE after 30 days of incubation was nearly 12% for Arthrobacter sp. and 15% for Pseudomonas sp. The bacterial adhesion to hydrocarbon (BATH) assay showed that the cell surface hydrophobicity of Pseudomonas sp. was higher than Arthrobacter sp. Both fluorescein diacetate hydrolysis and protein content of the biofilm were used to test the viability and protein density of the biomass. Acute peak elevation was observed between 2 and 5 days of inoculation for both bacteria. Fourier transform infrared (FT-IR) spectrum showed that keto carbonyl bond index (KCBI), Ester carbonyl bond index (ECBI) and Vinyl bond index (VBI) were increased indicating changes in functional group(s) and/or side chain modification confirming the biodegradation. The results pose us to suggest that both Pseudomonas sp. and Arthrobacter sp. were proven efficient to degrade HDPE, albeit the former was more efficacious, yet the ability of latter cannot be neglected. Recent alarm on ecological threats to marine system is dumping plastic waste in the marine ecosystem and coastal arena by anthropogenic activity. In maintenance phase of the plastic-derived polyethylene waste, the microbial degradation plays a major role; the information accomplished in this work will be the initiating point for the degradation of polyethylene by indigenous bacterial population in the marine ecosystem and provides a novel eco-friendly solution in eco-management.

Fabrication and mechanical properties of self-reinforced poly(ethylene terephthalate composites

Directory of Open Access Journals (Sweden)

2011-03-01

Full Text Available Self-reinforced poly(ethylene terephthalate (PET composites prepared by using a modified film-stacking technique were examined in this study. The starting materials included a high tenacity PET yarn (reinforcement and a low melting temperature biodegradable polyester resin (matrix, both of which differ in their melting temperatures with a value of 56°C. This experiment produced composite sheets at three consolidation temperatures (Tc: 215, 225, and 235°C at a constant holding time (th: 6.5 min, and three holding times (3, 6.5 and 10 min at a constant consolidation temperature of 225°C. This study observed a significant improvement in the mechanical properties obtained in self-reinforced PET composites compared to the pure polyester resin. The results of tensile, flexural, and Izod impact tests proved that optimal conditions are low consolidation temperature and short holding time. The absorbed impact energy of the best self-reinforced PET composite material was 854.0 J/m, which is 63 times that of pure polyester resin.

The influence of oxidation on space charge formation in gamma-irradiated low-density polyethylene

CERN Document Server

Chen, G; Xie, H K; Banford, H M; Davies, A E

2003-01-01

The research presented in this paper investigates the role of oxidation in the formation of space charge in gamma-irradiated low-density polyethylene after being electrically stressed under dc voltage. Polyethylene plaques both with and without antioxidant were irradiated up to 500 kGy using a sup 6 sup 0 Co gamma source and space charge distributions were measured using the piezoelectric induced pressure wave propagation method. It has been found that a large amount of positive charge evolved adjacent to the cathode in the sample without antioxidant and was clearly associated with oxidation of the surface. The amount of charge formed for a given applied stress increased with the dose absorbed by the material. A model has been proposed to explain the formation of space charge and its profile. The charge decay after the removal of the external applied stress is dominated by a process being controlled by the cathode interfacial stress (charge injection) rather than a conventional RC circuit model. On the other ...

Formulation and characterization of polyethylenes and organo-clays. Barrier properties of the obtained nano-composites; Formulation et caracterisation de polyethylenes charges avec des argiles. Proprietes barriere des nanocomposites obtenus

Energy Technology Data Exchange (ETDEWEB)

Wache, R

2004-10-01

The particularity of polymer layered silicate nano-composites is based on the exfoliation of the clay platelets in the polymer matrix. Therefore properties may be dramatically modified with very low clay loading. In this work polyethylene and organo-clay have been melt blended. Due to a lack of polarity, the polymer chains do not intercalate the clay stacking. However exfoliation is achieved using maleate polyethylene. We used this polymer as a compatibilizer to promote clay exfoliation in the polyethylene matrix. Partial exfoliation is obtained. Barrier properties of these materials have been characterized. Permeability is higher for the clay reinforced products than their matrix. To understand the poor permeability results a tortuosity model has been developed. The quality of the interface seems to be involved. Several organo-clays and compatibilizers have been tested to improve it. But for the concentrations of these products used polyethylene clay interactions always exist and lead to an increase of diffusion. (author)

Flow and breakup in extension of low-density polyethylene

DEFF Research Database (Denmark)

Rasmussen, Henrik; Fasano, Andrea

2018-01-01

The breakup during the extension of a low-density polyethylene Lupolen 1840D, as observed experimentally by Burghelea et al. (J Non-Newt Fluid Mech 166:1198–1209 2011), was investigated. This was observed during the extension of an circular cylinder with radius R0 = 4 mm and length L0 = 5mm....... The sample was attached to two flat end plates, separated exponentially in time to extend the samples. A numerical method based on a Lagrangian kinematics description in a continuum mechanical framework was used to calculate the extension of an initially cylindrically shaped sample with and without small...... the error bars as reported experimentally by Burghelea et al. (J Non-Newt Fluid Mech 166:1198–1209 2011). At low extensional rates, the measurements were considerably above the calculated ones. A very small relative suppression in the surface (0.1%) was required to achieve an agreement with all measurements...

Conversion of Mixed Plastic Wastes (High Density Polyethylene and Polypropylene) into Liquid Fuel

International Nuclear Information System (INIS)

Chaw Su Su Hmwe; Tint Tint Kywe; Moe Moe Kyaw

2010-12-01

In this study, mixed plastic wastes were converted into liquid fuels. Mixed plastic wastes used were high density polyethylene (HDPE) and polypropylene (PP). The pyrolysis of mixed plastic waste to liquid fuel was carried out with and without prepared zeolite catalyst.The catalyst was characterized by X-ray Diffraction (XRD). This catalyst was pre-treated for activation. The experiments were carried out at temperature range of 350-410C.Physical properties (density, kinematic, viscosity,refractive index)of prepared liquid fuel samples were measured. From this study, yields of liquid fuel and gas fuel were found to be 41-64% and 15-35% respectively. As for by products, char was obtained as the yield percentages from 9 to 14% and wax (yield% - 1 to 14) was formed during pyrolysis.

Rice husk ash – A valuable reinforcement for high density polyethylene

International Nuclear Information System (INIS)

Ayswarya, E.P.; Vidya Francis, K.F.; Renju, V.S.; Thachil, Eby Thomas

2012-01-01

Highlights: ► RHA is formed from the incineration of rice husk. ► RHA is mainly a mixture of silica with various metallic compounds. ► RHA is a valuable reinforcing material for HDPE. ► RHA can be incorporated into HDPE by the melt blending process. ► The best mechanical properties are observed at 1.5% RHA and 15% compatibilizer. -- Abstract: This paper presents the results of a study on the use of rice husk ash (RHA) for property modification of high density polyethylene (HDPE). Rice husk is a waste product of the rice processing industry. It is used widely as a fuel which results in large quantities of RHA. Here, the characterization of RHA has been done with the help of X-ray diffraction (XRD), Inductively Coupled Plasma Atomic Emission Spectroscopy (ICPAES), light scattering based particle size analysis, Fourier transform infrared spectroscopy (FTIR) and Scanning Electron Microscope (SEM). Most reports suggest that RHA when blended directly with polymers without polar groups does not improve the properties of the polymer substantially. In this study RHA is blended with HDPE in the presence of a compatibilizer. The compatibilized HDPE-RHA blend has a tensile strength about 18% higher than that of virgin HDPE. The elongation-at-break is also higher for the compatibilized blend. TGA studies reveal that uncompatibilized as well as compatibilized HDPE-RHA composites have excellent thermal stability. The results prove that RHA is a valuable reinforcing material for HDPE and the environmental pollution arising from RHA can be eliminated in a profitable way by this technique.

Low-pressure plasma enhanced immobilization of chitosan on low-density polyethylene for bio-medical applications

International Nuclear Information System (INIS)

Pandiyaraj, K. Navaneetha; Ferraria, Ana Maria; Rego, Ana Maria Botelho do; Deshmukh, Rajendra R.; Su, Pi-Guey; Halleluyah, Jr. Mercy; Halim, Ahmad Sukari

2015-01-01

Highlights: • Acrylic acid (AAc) was grafted on LDPE film by in situ plasma polymerization. • Molecules of PEG and chitosan were immobilized on AAc grafted LDPE films. • Surface modified LDPE exhibits excellent hydrophilic property. • Surface modified LDPE resist the adsorption of protein and adhesion of platelets. - Abstract: With the aim of improving blood compatibility of low density polyethylene (LDPE) films, an effective low-pressure plasma technology was employed to functionalize the LDPE film surfaces through in-situ grafting of acrylic acid (AAc). Subsequently, the molecules of poly(ethylene glycol) (PEG) and chitosan (CHI) were immobilized on the surface of grafted LDPE films. The unmodified and modified LDPE films were analyzed using various characterization techniques such as contact angle, atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR) and X-ray photo electron spectroscopy (XPS) to understand the changes in surface properties such as hydrophilicity, surface topography and chemical composition, respectively. Furthermore, LDPE films have been subjected to an ageing process to determine the durability of the plasma assisted surface modification. The blood compatibility of the surface modified LDPE films was confirmed by in vitro tests. It was found that surface modified LDPE films show better hydrophilic behavior compared with the unmodified one. FTIR and XPS results confirm the successful immobilization of CHI on the surface of LDPE films. LDPE films showed marked morphological changes after grafting of AAc, PEG and CHI which were confirmed through AFM imaging. The in vitro blood compatibility tests have clearly demonstrated that CHI immobilized LDPE films exhibit remarkable anti thrombogenic nature compared with other modified films. Surface modified LDPE films through low-pressure plasma technique could be adequate for biomedical implants such as artificial skin substrates, urethral catheters or cardiac stents

Low-pressure plasma enhanced immobilization of chitosan on low-density polyethylene for bio-medical applications

Energy Technology Data Exchange (ETDEWEB)

Pandiyaraj, K. Navaneetha, E-mail: dr.knpr@gmail.com [Surface Engineering Laboratory, Department of Physics, Sri Shakthi Institute of Engineering and Technology, L& T by pass, Chinniyam Palayam (post), Coimbatore, 641062 (India); Ferraria, Ana Maria; Rego, Ana Maria Botelho do [Centro de Química- Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, University of Lisbon (Portugal); Deshmukh, Rajendra R. [Department of Physics, Institute of Chemical Technology, Matunga, Mumbai 400 019 (India); Su, Pi-Guey [Department of Chemistry, Chinese Culture University, Taipei 111, Taiwan (China); Halleluyah, Jr. Mercy; Halim, Ahmad Sukari [Reconstructive Science Unit, School of Medical Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan (Malaysia)

2015-02-15

Highlights: • Acrylic acid (AAc) was grafted on LDPE film by in situ plasma polymerization. • Molecules of PEG and chitosan were immobilized on AAc grafted LDPE films. • Surface modified LDPE exhibits excellent hydrophilic property. • Surface modified LDPE resist the adsorption of protein and adhesion of platelets. - Abstract: With the aim of improving blood compatibility of low density polyethylene (LDPE) films, an effective low-pressure plasma technology was employed to functionalize the LDPE film surfaces through in-situ grafting of acrylic acid (AAc). Subsequently, the molecules of poly(ethylene glycol) (PEG) and chitosan (CHI) were immobilized on the surface of grafted LDPE films. The unmodified and modified LDPE films were analyzed using various characterization techniques such as contact angle, atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR) and X-ray photo electron spectroscopy (XPS) to understand the changes in surface properties such as hydrophilicity, surface topography and chemical composition, respectively. Furthermore, LDPE films have been subjected to an ageing process to determine the durability of the plasma assisted surface modification. The blood compatibility of the surface modified LDPE films was confirmed by in vitro tests. It was found that surface modified LDPE films show better hydrophilic behavior compared with the unmodified one. FTIR and XPS results confirm the successful immobilization of CHI on the surface of LDPE films. LDPE films showed marked morphological changes after grafting of AAc, PEG and CHI which were confirmed through AFM imaging. The in vitro blood compatibility tests have clearly demonstrated that CHI immobilized LDPE films exhibit remarkable anti thrombogenic nature compared with other modified films. Surface modified LDPE films through low-pressure plasma technique could be adequate for biomedical implants such as artificial skin substrates, urethral catheters or cardiac stents

Amperometric Biosensor Based on Zirconium Oxide/Polyethylene Glycol/Tyrosinase Composite Film for the Detection of Phenolic Compounds

Directory of Open Access Journals (Sweden)

Nor Monica Ahmad

2016-06-01

Full Text Available A phenolic biosensor based on a zirconium oxide/polyethylene glycol/tyrosinase composite film for the detection of phenolic compounds has been explored. The formation of the composite film was expected via electrostatic interaction between hexacetyltrimethylammonium bromide (CTAB, polyethylene glycol (PEG, and zirconium oxide nanoparticles casted on screen printed carbon electrode (SPCE. Herein, the electrode was treated by casting hexacetyltrimethylammonium bromide on SPCE to promote a positively charged surface. Later, zirconium oxide was mixed with polyethylene glycol and the mixture was dropped cast onto the positively charged SPCE/CTAB. Tyrosinase was further immobilized onto the modified SPCE. Characterization of the prepared nanocomposite film and the modified SPCE surface was investigated by scanning electron microscopy (SEM, Electrochemical Impedance Spectroscopy (EIS, and Cyclic voltamogram (CV. The developed biosensor exhibits rapid response for less than 10 s. Two linear calibration curves towards phenol in the concentrations ranges of 0.075–10 µM and 10–55 µM with the detection limit of 0.034 µM were obtained. The biosensor shows high sensitivity and good storage stability for at least 30 days.

Effect of ultraviolet radiation in the photo-oxidation of High Density Polyethylene and Biodegradable Polyethylene films

International Nuclear Information System (INIS)

Martínez-Romo, A; Mota, R González; Bernal, J J Soto; Candelas, I Rosales; Reyes, C Frausto

2015-01-01

One of the most widely used plastics in the world is the High density polyethylene (HDPE), it is a stable material due to its carbon-carbon bonds, causing their slow degradation; which is why we are looking for alternative ways to accelerate the degradation process of this polymer. An alternative is the addition of oxidized groups in its molecular structure, which results in the development of polymers susceptible to biodegradation (PE-BIO). In this paper, HDPE and PE-BIO films were exposed to UV-B radiation (320-280 nm) at different exposure times, 0-60 days. The effects of UV radiation in samples of HDPE and PE-BIO were characterized using infrared spectroscopy with attenuated total reflectance (ATR). The results show that the exposed materials undergo changes in their molecular structure, due to the infrared bands formed which corresponds to the photo-oxidation of HDPE and PE films when submitted to UV-B radiation

The impact of nanoclay on the crystal growth kinetics and morphology of biodegradable poly(ethylene succinate) composite

CSIR Research Space (South Africa)

Bandyopadhyay, J

2012-07-01

Full Text Available The impact of nanoclay on the isothermal crystal growth kinetics and morphology of biodegradable poly(ethylene succinate) (PES) is reported. A PES composite (PESNC) containing 5 wt% organically modified montmorillonite, was prepared via solvent...

Facile Fabrication of Electrically Conductive Low-Density Polyethylene/Carbon Fiber Tubes for Novel Smart Materials via Multiaxial Orientation.

Science.gov (United States)

Li, Yijun; Nie, Min; Wang, Qi

2018-01-10

Electromechanical sensors are indispensable components in functional devices and robotics application. However, the fabrication of the sensors still maintains a challenging issue that high percolation threshold and easy failure of conductive network are derived from uniaxial orientation of conductive fillers in practical melt processing. Herein, we reported a facile fabrication method to prepare a multiaxial low-density polyethylene (LDPE)/carbon fibers (CFs) tube with bidirectional controllable electrical conductivity and sensitive strain-responsive performance via rotation extrusion technology. The multidimensional helical flow is confirmed in the reverse rotation extrusion, and the CFs readily respond to the flow field leading to a multiaxial orientation in the LDPE matrix. In contrast to uniaxial LDPE/CF composites, which perform a "head to head" conjunction, multiaxial-orientated CF networks exhibit a unique multilayer structure in which the CFs with distinct orientation direction intersect in the interface, endowing the LDPE/CF composites with a low percolation threshold (15 wt %) to those of the uniaxial ones (∼35 wt %). The angles between two axes play a vital role in determining the density of the conductive networks in the interface, which is predominant in tuning the bending-responsive behaviors with a gauge factor range from 12.5 to 56.3 and the corresponding linear respond region from ∼15 to ∼1%. Such a superior performance of conductive LDPE/CF tube confirms that the design of multiaxial orientation paves a novel way to facile fabrication of advanced cost-effective CF-based smart materials, shedding light on promising applications such as smart materials and intelligent engineering monitoring.

Structure and thermal performance of poly(ethylene glycol) alkyl ether (Brij)/porous silica (MCM-41) composites as shape-stabilized phase change materials

Energy Technology Data Exchange (ETDEWEB)

Zhang, Lingjian; Shi, Haifeng, E-mail: haifeng.shi@gmail.com; Li, Weiwei; Han, Xu; Zhang, Xingxiang, E-mail: zhangpolyu@gmail.com

2013-10-20

Graphical abstract: The maximum 50 wt% Brij58 is loaded into the porous MCM-41 networks, and a new peak at 18.8° in XRD patterns confirmed the changes of crystallization behavior of Brij58 against the bulk one. - Highlights: • Poly(ethylene glycol) hexadecyl ether and poly(ethylene glycol) octadecyl ether have the good thermal storage ability. • New peak at 18.8° proved the coexisted confined crystallization and nucleation-induced crystallization. • Poly(ethylene glycol) alkyl ether/MCM-41 PCMs exhibits the good thermal stability. - Abstract: A series of shape-stabilized phase change materials (PCMs), composed of poly(ethylene glycol) hexadecyl ether (Brij58) or poly(ethylene glycol) octadecyl ether (Brij76) and porous silica (MCM-41), were prepared by the physical mixing method. The structure, thermal stability, energy storage ability and crystallization behavior of these composites are deeply investigated and characterized by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), wide-angle X-ray diffraction (WAXD) and thermogravimetric analysis (TGA). Obvious phase transition behavior and energy storage capability are observed for these Brij/MCM-41 composites, and the heat storage efficiency increased with the weight of Brij component. New peak at 18.8° demonstrated that the pore size and the surface adsorption ability of MCM-41 affect the crystallization behavior of Brij molecule. The crystalline structure and energy storage ability of these Brij/MCM-41 composites are discussed based on the crystallization process.

Mechanical and thermal properties of biocomposites from nonwoven industrial Fique fiber mats with Epoxy Resin and Linear Low Density Polyethylene

Science.gov (United States)

Hidalgo-Salazar, Miguel A.; Correa, Juan P.

2018-03-01

In this work Linear Low Density Polyethylene-nonwoven industrial Fique fiber mat (LLDPE-Fique) and Epoxy Resin-nonwoven industrial Fique fiber mat (EP-Fique) biocomposites were prepared using thermocompression and resin film infusion processes. Neat polymeric matrices and its biocomposites were tested following ASTM standards in order to evaluate tensile and flexural mechanical properties. Also, thermal behavior of these materials has been studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Tensile and flexural test revealed that nonwoven Fique reinforced composites exhibited higher modulus and strength but lower deformation capability as compared with LLDPE and EP neat matrices. TG thermograms showed that nonwoven Fique fibers incorporation has an effect on the thermal stability of the composites. On the other hand, Fique fibers did not change the crystallization and melting processes of the LLDPE matrix but restricts the motion of EP macromolecules chains thus increases the Tg of the EP-Fique composite. Finally, this work opens the possibility of considering non-woven Fique fibers as a reinforcement material with a high potential for the manufacture of biocomposites for automotive applications. In addition to the processing test specimens, it was also possible to manufacture a part of LLDPE-Fique, and one part of EP-Fique.

An investigation on chloroprene-compatibilized acrylonitrile butadiene rubber/high density polyethylene blends.

Science.gov (United States)

Ahmed, Khalil

2015-11-01

Blends of acrylonitrile butadiene rubber/high density polyethylene (NBR/HDPE) compatibilized by Chloroprene rubber (CR) were prepared. A fixed quantity of industrial waste such as marble waste (MW, 40 phr) was also included. The effect of the blend ratio and CR on cure characteristics, mechanical and swelling properties of MW-filled NBR/HDPE blends was investigated. The results showed that the MW-filled NBR/HDPE blends revealed an increase in tensile strength, tear, modulus, hardness and cross-link density for increasing weight ratio of HDPE. The minimum torque (M L) and maximum torque (M H) of blends increased with increasing weight ratio of HDPE while scorch time (ts2) cure time (tc90), compression set and abrasion loss of blends decreased with increasing weight ratio of HDPE. The blends also showed a continuous reduction in elongation at break as well as swelling coefficient with increasing HDPE amount in blends. MW filled blends based on CR provided the most encouraging balance values of overall properties.

An investigation on chloroprene-compatibilized acrylonitrile butadiene rubber/high density polyethylene blends

Directory of Open Access Journals (Sweden)

Khalil Ahmed

2015-11-01

Full Text Available Blends of acrylonitrile butadiene rubber/high density polyethylene (NBR/HDPE compatibilized by Chloroprene rubber (CR were prepared. A fixed quantity of industrial waste such as marble waste (MW, 40 phr was also included. The effect of the blend ratio and CR on cure characteristics, mechanical and swelling properties of MW-filled NBR/HDPE blends was investigated. The results showed that the MW-filled NBR/HDPE blends revealed an increase in tensile strength, tear, modulus, hardness and cross-link density for increasing weight ratio of HDPE. The minimum torque (ML and maximum torque (MH of blends increased with increasing weight ratio of HDPE while scorch time (ts2 cure time (tc90, compression set and abrasion loss of blends decreased with increasing weight ratio of HDPE. The blends also showed a continuous reduction in elongation at break as well as swelling coefficient with increasing HDPE amount in blends. MW filled blends based on CR provided the most encouraging balance values of overall properties.

Biodegradation of low density polyethylene by the action of a microbial consortium isolated from a landfill, Lima, Peru

Directory of Open Access Journals (Sweden)

Diego Uribe

2011-05-01

Full Text Available In this paper, we describe the isolation and biodegradation activity of microorganisms on low density polyethylene. The microorganisms were collected from plastic materials with evidence of deterioration from a landfill. The samples were filtered and selected in a mineral salts medium at pH 5.5 and 7 for bacteria and fungi respectively. Six strains were isolated, identified as Pseudomonas sp. Hyalodendron sp., Penicillium sp. and Rhodotorula sp. Microbial activity was evidenced by changes in the infrared spectrum of polyethylene with respect to the polymer without treatment. Reduction of carbonyl index (83.89% at pH 7 and 4.08% at pH 5.5 and double bonds index (19.77% at pH 7 and 6.47% at pH 5.5 were observed. Finally we determined the percentage of weight lost by the polyethylene subjected to activity of the strains, with a decrease of 5.4% at pH 7 and 4.8% at pH5, 5.

Gamma irradiation effects on the grafting of low-density polyethylene with diethyl maleate

International Nuclear Information System (INIS)

Sanchez, Y.; Albano, C.; Karam, A.; Perera, R.; Silva, P.; Gonzalez, J.

2005-01-01

In this work, a low-density polyethylene (LDPE) was grafted with diethyl maleate (DEM) using gamma-rays from a Cobalt-60 source at different absorbed doses and monomer concentrations between 5 and 30 wt.%. This process was carried out in a decalin solution at 10 w/v% to obtain a homogeneous dispersion of the monomer into the polyethylene matrix. It was found that the grafting degree increases with the absorbed doses, as a consequence of the increased amount of energy given to the system, which made the grafting process more favorable. The grafting degree also increases with the concentration of DEM, because a higher concentration makes the insertion easier due to the increased availability of the free monomer. The highest grafting degree was obtained at 200 kGy of absorbed dose and with 30 wt.% of DEM. The melt flow index (MFI) values showed a decreasing trend as the absorbed dose was increased. This fact reveals that crosslinking and grafting are taking place simultaneously, this behavior being remarkable at higher irradiation doses. The results from thermogravimetric analysis (TGA) showed that the initial degradation temperatures remained almost unchanged with the absorbed dose

Electrical properties and features of the crystallization behaviour and the phase morphology of polyethylene blends

International Nuclear Information System (INIS)

Kolesov, I.S.; Radusch, H.-J.; Kolesov, S.N.

1999-01-01

It was discovered that polyethylene blends show a typical concentration dependence of the specific electrical resistance and the electrical strength measured by the surge voltage method. The concentration dependencies show two local maxima at definite blend compositions (ω LDPE = 0,2 to 0,4 and 0,7 to 0,8). The results of investigation of the melt and crystallization behavior as well as of the supermolecular structure of these blends point out that the changes caused by mixing in topology and packaging density of the inter-phases between the phases and crystallites have an influence on the electrical properties of the polyethylene blends in correspondence to the composition. The changed structure-property relationships are caused essentially by a possible co-crystallization of the components and by the interactions at separate seeds formation. (orig.)

Hyperbranched polyester polyol plasticized tapioca starch/low density polyethylene blends

Energy Technology Data Exchange (ETDEWEB)

Guzman, Manuel; Giraldo, Diego; Murillo, Edwin, E-mail: edwinalbertomurillo@gmail.com [Universidad de Antioquia, Medellin (Colombia); Universidad Francisco de Paula Santander, San Jose de Cucuta (Colombia)

2017-01-15

n this work, low density polyethylene (LDPE)/plasticised starch (TPS) blends were prepared. The TPS employed in this study was obtained by plasticization of tapioca starch with a hyperbranched polyester polyol. Differential scanning calorimetry analysis showed that the melting temperature increased with the TPS content. The opposite effect was exhibited in the crystallization temperature and additional changes were not observed during the heating. X-ray diffraction analysis showed a reduction in intensity of the peak at Bragg’s angle 17.5°, proving a diminution on A type crystallinity with the increasing amount of LDPE. Micrographs obtained by scanning electron microscopy exhibited starch granules without destructure. TPS acted as a filler to LDPE, since the mechanical properties (Young's modulus and tensile strength) improved ostensibly. The Young' modulus and tensile strength decreased with the amount of LDPE, however, the elongation at break exhibited an opposite behavior. (author)

Hyperbranched polyester polyol plasticized tapioca starch/low density polyethylene blends

Directory of Open Access Journals (Sweden)

Manuel Guzmán

Full Text Available Abstract In this work, low density polyethylene (LDPE/plasticized starch (TPS blends were prepared. The TPS employed in this study was obtained by plasticization of tapioca starch with a hyperbranched polyester polyol. Differential scanning calorimetry analysis showed that the melting temperature increased with the TPS content. The opposite effect was exhibited in the crystallization temperature and additional changes were not observed during the heating. X-ray diffraction analysis showed a reduction in intensity of the peak at Bragg’s angle 17.5°, proving a diminution on A type crystallinity with the increasing amount of LDPE. Micrographs obtained by scanning electron microscopy exhibited starch granules without destructure. TPS acted as a filler to LDPE, since the mechanical properties (Young’s modulus and tensile strength improved ostensibly. The Young’ modulus and tensile strength decreased with the amount of LDPE, however, the elongation at break exhibited an opposite behavior.

The alterations in high density polyethylene properties with gamma irradiation

Science.gov (United States)

Zaki, M. F.; Elshaer, Y. H.; Taha, Doaa. H.

2017-10-01

In the present investigation, high density polyethylene (HDPE) polymer has been used to study the alterations in its properties under gamma-irradiation. Physico-chemical properties have been investigated with different spectroscopy techniques, Fourier Transform Infrared spectroscopy (FTIR), X-ray diffraction (XRD), biocompatibility properties, as well as, mechanical properties change. The FT-IR analysis shows the formation of new band at 1716 cm-1 that is attributed to the oxidation of irradiated polymer chains, which is due to the formation of carbonyl groups (C˭O). XRD patterns show that a decrease in the crystallite size and increase in the Full Width at Half Maximum (FWHM). This means that the crystallinity of irradiated samples is decreased with increase in gamma dose. The contact angle measurements show an increase in the surface free energy as the gamma irradiation increases. The measurements of mechanical properties of irradiated HDPE samples were discussed.

Hyperbranched polyester polyol plasticized tapioca starch/low density polyethylene blends

International Nuclear Information System (INIS)

Guzman, Manuel; Giraldo, Diego; Murillo, Edwin

2017-01-01

n this work, low density polyethylene (LDPE)/plasticised starch (TPS) blends were prepared. The TPS employed in this study was obtained by plasticization of tapioca starch with a hyperbranched polyester polyol. Differential scanning calorimetry analysis showed that the melting temperature increased with the TPS content. The opposite effect was exhibited in the crystallization temperature and additional changes were not observed during the heating. X-ray diffraction analysis showed a reduction in intensity of the peak at Bragg’s angle 17.5°, proving a diminution on A type crystallinity with the increasing amount of LDPE. Micrographs obtained by scanning electron microscopy exhibited starch granules without destructure. TPS acted as a filler to LDPE, since the mechanical properties (Young's modulus and tensile strength) improved ostensibly. The Young' modulus and tensile strength decreased with the amount of LDPE, however, the elongation at break exhibited an opposite behavior. (author)

Thermal and electrical conductivity enhancement of graphite nanoplatelets on form-stable polyethylene glycol/polymethyl methacrylate composite phase change materials

International Nuclear Information System (INIS)

Zhang, Lei; Zhu, Jiaoqun; Zhou, Weibing; Wang, Jun; Wang, Yan

2012-01-01

Graphite nanoplatelets (GnPs), obtained by sonicating the expanded graphite, were employed to simultaneously enhance the thermal (k) and electrical (σ) conductivity of organic form-stable phase change materials (FSPCMs). Using the method of in situ polymerization upon ultrasonic irradiation, GnPs serving as the conductive fillers and polyethylene glycol (PEG) acting as the phase change material (PCM) were uniformly dispersed and embedded inside the network structure of polymethyl methacrylate (PMMA), which contributed to the well package and self-supporting properties of composite FSPCMs. X-ray diffraction and Fourier transform infrared spectroscopy results indicated that the GnPs were physically combined with PEG/PMMA matrix and did not participate in the polymerization. The GnPs additives were able to effectively enhance the k and σ of organic FSPCM. When the mass ratio of GnP was 8%, the k and σ of FSPCM changed up to 9 times and 8 orders of magnitude over that of PEG/PMMA matrix, respectively. The improvements in both k and σ were mainly attributed to the well dispersion and large aspect ratio of GnPs, which were endowed with benefit of forming conducting network in polymer matrix. It was also confirmed that all the prepared specimens possessed available thermal storage density and thermal stability. -- Highlights: ► GnPs were employed to simultaneously enhance the k and σ of organic FSPCMs. ► PEG/PMMA/GnPs composite FSPCMs were prepared by in situ polymerization method. ► The composite FSPCMs exhibited well package and self-supporting properties. ► GnPs additives effectively enhanced the k and σ of composite FSPCMs. ► All the composites possessed available thermal storage density and thermal stability.

The role of intramolecular crosslinking in the radiolysis of bulk crystallized high density polyethylene

International Nuclear Information System (INIS)

Lyons, B.J.

1986-01-01

Intramolecular crosslinks have been suggested to occur in bulk crystallized, irradiated, high density polyethylene (HDPE) and to account for the low rates of gel formation, especially those of previously annealed samples when compared with that manifested by the same resin when previously quenched from the melt. Such crosslinks do not contribute to the development of gel and contribute to only a limited extent to the elastic properties above the crystalline melting point when compared with intermolecular crosslinks, but, if the mesh size of the intra- and inter-molecular networks are comparable, are fully reflected in the rupture elongation. The rupture elongations of a wide range of HDPE resins, for a given sol fraction or elastic modulus, are found to be at least as high as and often higher than those of low (LDPE) or linear low (LLDPE) polyethylene resins, indicating that intramolecular crosslinking of this type does not occur to a significantly greater extent in these higher crystallinity resins. Other factors more likely to account for the reduced rates of inter alia gel formation in some HDPE resins are discussed. (author)

Measurement of radon permeability through polyethylene membrane using scintillation detector

Energy Technology Data Exchange (ETDEWEB)

Ashry, A.H.; Abou-Leila, M. [Department of Physics, Faculty of Education, Ain Shams University, Cairo (Egypt); Abdalla, A.M., E-mail: aymanabdalla62@hotmail.co [Department of Physics, Faculty of Education, Ain Shams University, Cairo (Egypt); Department of Physics, Faculty of Sciences and Arts, Najran University, Najran, P.O. Box. 11001 (Saudi Arabia); Advanced Materials and Nano-Engineering Laboratory (AMNEL), Centre for Advanced Materials and Nano-Engineering (CAMNE), Najran University, Najran, P.O. Box. 11001 (Saudi Arabia)

2011-01-15

The permeability of Radon 222 through polyethylene membranes has been studied using activated charcoal technique. The permeability constant of Radon 222 through low-density polyethylene, linear low-density Polyethylene and high density polyethylene samples has been measured. There is a considerable agreement between the values obtained by our method and the method suggested by W. Arafa [2002. Permeability of radon 222 through some materials. Radiat. Meas. 35, 207-211], and SSNTD technique suggested by A. Hafez and G. Somogyi [1986. Determination of radon and thoron permeability through some plastics by track technique. Int. J. Radiat. Appl. Instrum. Nucl. Track Radiat. Meas. 12 (1-6), 697-700]. In this work Radon permeability through different polyethylene membranes has been measured using three different methods, i.e. solid state nuclear track technique, W. Arafa [2002. Permeability of radon 222 through some materials. Radiat. Meas. 35, 207-211]method and our proposed method. In addition to this, in this study, the diffusion coefficient of radon in charcoal as well as solubility of Radon in polyethylene membrane has been taken into consideration.

Measurement of radon permeability through polyethylene membrane using scintillation detector

International Nuclear Information System (INIS)

Ashry, A.H.; Abou-Leila, M.; Abdalla, A.M.

2011-01-01

The permeability of Radon 222 through polyethylene membranes has been studied using activated charcoal technique. The permeability constant of Radon 222 through low-density polyethylene, linear low-density Polyethylene and high density polyethylene samples has been measured. There is a considerable agreement between the values obtained by our method and the method suggested by W. Arafa [2002. Permeability of radon 222 through some materials. Radiat. Meas. 35, 207-211], and SSNTD technique suggested by A. Hafez and G. Somogyi [1986. Determination of radon and thoron permeability through some plastics by track technique. Int. J. Radiat. Appl. Instrum. Nucl. Track Radiat. Meas. 12 (1-6), 697-700]. In this work Radon permeability through different polyethylene membranes has been measured using three different methods, i.e. solid state nuclear track technique, W. Arafa [2002. Permeability of radon 222 through some materials. Radiat. Meas. 35, 207-211] method and our proposed method. In addition to this, in this study, the diffusion coefficient of radon in charcoal as well as solubility of Radon in polyethylene membrane has been taken into consideration.

Conjunctivodacryocystorhinostomy using a high-density porous polyethylene-coated tear drain tube.

Science.gov (United States)

Pushker, Neelam; Khurana, Saurbhi; Shrey, Dinesh; Bajaj, Mandeep S; Chawla, Bhavna; Chandra, Mahesh

2013-08-01

To evaluate the outcome of conjunctivodacryocystorhinostomy using a high-density porous polyethylene (HDPP)-coated tear drain tube. Patients with epiphora due to a proximal lacrimal system block were included in a prospective interventional case study. A total of 22 eyes were treated with lacrimal bypass surgery using the HDPP-coated tube. On follow-up (12-41 months), 21 eyes had a patent well-positioned tube with subjective relief of epiphora. In one eye, a loose sleeve was noted during surgery. The tube dislodged postoperatively and was removed. A high success rate with only a few minor complications is achievable using a HDPP-coated tear drain tube for lacrimal bypass surgery. Long-term follow-up is required to look for tube blockage due to conjunctival or nasal mucosal overgrowth.

Radiation effect on polyethylene tube operational properties

International Nuclear Information System (INIS)

Kagan, D.F.; Kantor, L.A.; Sokolov, I.A.; Pogrebetskij, G.E.; Perlova, N.A.; Chumakov, V.V.

1975-01-01

The operational properties (stability on prolonged usage and creeping) were determined for pressure pipes made of high-density and low-density polyethylene subjected to γ-radiation. The dependence of the period up to the breaking point on the radiation dosage was extreme in character, with a maximum being near 25 Mrad. With an increase in the irradiation dosage the character of the breaking changes from plastic (at 0-15 Mrad) to brittle (at higher dosages). The plots of creepage, indepent from the amount of radiation, can be described by logarithmic equation epsilon=epsilonsub(0)+K lgt (where, epsilon-deformation of creepage, %; epsilonsub(0)- and K - creepage constants). Therefore creepage can be considered as a criterion determining the carrying capacity of the γ-irradiated polyethylene. It was established that only radiation-grafted high-density polyethylene is suitable for hot water supply pipes

Influence of nanoclay on properties of HDPE/wood composites

Science.gov (United States)

Yong Lei; Qinglin Wu; Craig M. Clemons; Fei Yao; Yanjun Xu

2007-01-01

Composites based on high density polyethylene (HDPE), pine flour, and organic clay were made by melt compounding and then injection molding. The influence of clay on crystallization behavior, mechanical properties, water absorption, and thermal stability of HDPE/pine composites was investigated. The HDPE/pine composites containing exfoliated clay were made by a two-...

Solid polymer electrolyte on the basis of polyethylene carbonate-lithium perchlorate system

International Nuclear Information System (INIS)

Dukhanin, G.P.; Dumler, S.A.; Sablin, A.N.; Novakov, I.A.

2009-01-01

Reaction in the system polyethylene carbonate-lithium perchlorate was investigated by IR spectroscopy, differential thermal and X-ray structural analyses. Specific electric conductivity of the prepared composition has been measured. Solid polymer electrolytes on the basis of polyethylene carbonate have conducting properties as electrolytes on the basis of unmodified polyethylene oxide. Compositions of polyethylene carbonate : LiClO 4 =10 : 1Al 2 O 3 -ZrO 2 possess maximum value of electrical conductivity. Activation energies of the process is calculated for all investigated compositions, and dependence of these values from concentration of lithium perchlorate is established

RF plasma cleaning of silicon substrates with high-density polyethylene contamination

Science.gov (United States)

Cagomoc, Charisse Marie D.; De Leon, Mark Jeffry D.; Ebuen, Anna Sophia M.; Gilos, Marlo Nicole R.; Vasquez, Magdaleno R., Jr.

2018-01-01

Upon contact with a polymeric material, microparticles from the polymer may adhere to a silicon (Si) substrate during device processing. The adhesion contaminates the surface and, in turn, leads to defects in the fabricated Si-based microelectronic devices. In this study, Si substrates with artificially induced high-density polyethylene (HDPE) contamination was exposed to 13.56 MHz radio frequency (RF) plasma utilizing argon and oxygen gas admixtures at a power density of 5.6 W/cm2 and a working pressure of 110 Pa for up to 6 min of treatment. Optical microscopy studies revealed the removal of up to 74% of the polymer contamination upon plasma exposure. Surface free energy (SFE) increased owing to the removal of contaminants as well as the formation of polar groups on the Si surface after plasma treatment. Atomic force microscopy scans showed a decrease in surface roughness from 12.25 nm for contaminated samples to 0.77 nm after plasma cleaning. The smoothening effect can be attributed to the removal of HDPE particles from the surface. In addition, scanning electron microscope images showed that there was a decrease in the amount of HDPE contaminants adhering onto the surface after plasma exposure.

Radiation Graft Copolymerization of Butyl methacrylate and Acrylamide onto Low density polyethylene and polypropylene films and its application in wastewater treatment

International Nuclear Information System (INIS)

Abdel Ghaffar, A.M.; El-Arnaouty, M.B.; Aboulfotouh, M.E.; Taher, N.H.

2012-01-01

Butyl methacrylate and Acrylamide (BMA/AAm) comonomer were grafted onto Low density polyethylene and polypropylene films using direct gamma radiation by grafting technique. The influences of grafting conditions such as solvent, monomer concentration, monomer composition, and irradiation dose on the grafting yield were determined. It was found that, using DMF as a solvent enhanced the copolymerization process. The grafting yield increases with comonomer concentration up to 60 %. . Also it was found that, the degree of grafting of (BMA/AAm) onto LDPE and PP films increases as the AAm content increases till optimum value at (50:50) %. The grafting yield of the comonomer found to be increased with increasing radiation dose. It was observed that the degree of grafting of polyethylene films is higher than that for polypropylene films. Some selected properties of the graft copolymers, such as water uptake and thermal properties determined by using thermogravimetric analysis (TGA) has been carried out. The morphology and structure of grafted films was investigated by using SEM, IR and X-ray diffraction. The improvement in such properties of the prepared copolymers was observed which makes possible uses in some practical applications such as in the removal of some heavy metals from wastewater. It was found that the maximum metal uptake by the copolymer is ordered in the sequence of Cu 2+ > CO 2+ > Ni 2+ ions.

New three-phase polymer-ceramic composite materials for miniaturized microwave antennas

Directory of Open Access Journals (Sweden)

Li Zhang

2016-09-01

Full Text Available Unique polymer-ceramic composites for microwave antenna applications were prepared via melt extrusion using high-density polyethylene (HDPE as the matrix and low-density polyethylene (LDPE coated BaO–Nd2O3–TiO2 (BNT ceramic-powders as the filler. By incorporating LDPE into the composites via a coating route, high ceramic-powder volume content (up to 50 vol% could be achieved. The composites exhibited good microwave dielectric and thermomechanical behaviors. As BNT ceramic content increased from 10 vol% to 50 vol%, the permittivity of the composites increased from 3.45 (9 GHz to 11.87 (7 GHz, while the dielectric loss remained lower than 0.0016. Microstrip antennas for applications in global positioning systems (GPS were designed and fabricated from the composites containing 50 vol% BNT ceramics. The results indicate that the composites that have suitable permittivity and low dielectric loss are promising candidates for applications in miniaturized microwave devices, such as antennas.

New three-phase polymer-ceramic composite materials for miniaturized microwave antennas

Science.gov (United States)

Zhang, Li; Zhang, Jie; Yue, Zhenxing; Li, Longtu

2016-09-01

Unique polymer-ceramic composites for microwave antenna applications were prepared via melt extrusion using high-density polyethylene (HDPE) as the matrix and low-density polyethylene (LDPE) coated BaO-Nd2O3-TiO2 (BNT) ceramic-powders as the filler. By incorporating LDPE into the composites via a coating route, high ceramic-powder volume content (up to 50 vol%) could be achieved. The composites exhibited good microwave dielectric and thermomechanical behaviors. As BNT ceramic content increased from 10 vol% to 50 vol%, the permittivity of the composites increased from 3.45 (9 GHz) to 11.87 (7 GHz), while the dielectric loss remained lower than 0.0016. Microstrip antennas for applications in global positioning systems (GPS) were designed and fabricated from the composites containing 50 vol% BNT ceramics. The results indicate that the composites that have suitable permittivity and low dielectric loss are promising candidates for applications in miniaturized microwave devices, such as antennas.

Bio-oil production via co-pyrolysis of almond shell as biomass and high density polyethylene

International Nuclear Information System (INIS)

Önal, Eylem; Uzun, Başak Burcu; Pütün, Ayşe Eren

2014-01-01

Highlights: • We investigate to see the effect of HDPE addition on thermal decomposition of lignocellulosic materials. • Increasing the proportion of HDPE in mixtures increases the oil yields. • After co-pyrolysis applied, obtained oil is more stable due to having lower oxygen content and higher heating value. • The addition of HDPE to aS has a positive effect on fuel properties of obtained oil. - Abstract: Biomass from almond shell (aS) was co-pyrolyzed with high density polyethylene (HDPE) polymer to investigate the synergistic effects on the product yields and compositions. The pyrolysis temperature was selected as 500 °C, based on results of TGA-DTG. Co-pyrolysis of HDPE-biomass mixtures were pyrolysed with various proportions such as 1:0, 1:1, 1:2, 2:1 and 0:1. The yield of liquids produced during co-pyrolysis enhanced 23%, as the weight ratio of HDPE in the mixture was doubled. Obtained bio-oils were analyzed with using column chromatography, 1 H NMR, GC/MS, and FT-IR. According to analyses results, produced liquids by co-pyrolysis had higher carbon (26% higher) and hydrogen contents (78% higher), lower oxygen content (%86 less) with a higher heating value (38% higher) than those of biomass oil

Characterization of the degree of cross-linking in radiation cross-linked low and high density polyethylenes

International Nuclear Information System (INIS)

Posselt, K.; Haedrich, W.

1986-01-01

In practice the cross-linking of irradiated polyethylene is mostly characterized by solubility and thermomechanical data. The irradiation of samples of a LDPE and a HDPE yields very different gel-dose curves. But for a quantitative comparison the complicated connection between the gel values and the corresponding densities of cross-links, especially the dependence on the initial molecular size distribution, has to take into consideration. The analysis of the solubility data according to the statistical theory of cross-linking developed by Inokuti and Saito shows that at equal doses in both investigated PE types in spite of the different gel values nearly the same densities of cross-links are present. That result is confirmed by the densities of cross-links determined from stress-strain measurements at 423 K. (author)

Natural fibre high-density polyethylene and lead oxide composites for radiation shielding

CERN Document Server

El-Sayed, A; Ismail, M R

2003-01-01

Study has been made of the radiation shielding provided by recycled agricultural fibre and industrial plastic wastes produced as composite materials. Fast neutron and gamma-ray spectra behind composites of fibre-plastic (rho = 1.373 g cm sup - sup 3) and fibre-plastic-lead (rho = 2.756 g cm sup - sup 3) have been measured using a collimated reactor beam and neutron-gamma spectrometer with a stilbene scintillator. The pulse shape discriminating technique based on the zero-cross-over method was used to discriminate between neutron and gamma-ray pulses. Slow neutron fluxes have been measured using a collimated reactor beam and BF sub 3 counter, leading to determination of the macroscopic cross-section (SIGMA). The removal cross-sections (SIGMA sub R) of fast neutrons have been determined from measured results and elemental composition of the composites. For gamma-rays, total linear attenuation coefficients (mu) and total mass attenuation coefficients (mu/rho) have been determined from use of the XCOM code and me...

Mechanical and thermal properties of biocomposites from nonwoven industrial Fique fiber mats with Epoxy Resin and Linear Low Density Polyethylene

Directory of Open Access Journals (Sweden)

Miguel A. Hidalgo-Salazar

2018-03-01

Full Text Available In this work Linear Low Density Polyethylene-nonwoven industrial Fique fiber mat (LLDPE-Fique and Epoxy Resin-nonwoven industrial Fique fiber mat (EP-Fique biocomposites were prepared using thermocompression and resin film infusion processes. Neat polymeric matrices and its biocomposites were tested following ASTM standards in order to evaluate tensile and flexural mechanical properties. Also, thermal behavior of these materials has been studied by differential scanning calorimetry (DSC and thermogravimetric analysis (TGA. Tensile and flexural test revealed that nonwoven Fique reinforced composites exhibited higher modulus and strength but lower deformation capability as compared with LLDPE and EP neat matrices. TG thermograms showed that nonwoven Fique fibers incorporation has an effect on the thermal stability of the composites. On the other hand, Fique fibers did not change the crystallization and melting processes of the LLDPE matrix but restricts the motion of EP macromolecules chains thus increases the Tg of the EP-Fique composite. Finally, this work opens the possibility of considering non-woven Fique fibers as a reinforcement material with a high potential for the manufacture of biocomposites for automotive applications. In addition to the processing test specimens, it was also possible to manufacture a part of LLDPE-Fique, and one part of EP-Fique. Keywords: Biocomposites, Natural materials, Nonwoven Fique fiber mat, LLDPE, Epoxy Resin

Effect of Die Head Temperature at Compounding Stage on the Degradation of Linear Low Density Polyethylene/Plastic Film Waste Blends after Accelerated Weathering

Directory of Open Access Journals (Sweden)

S. M. Al-Salem

2016-01-01

Full Text Available Accelerated weathering test was performed on blends of linear low density polyethylene (LLDPE and plastic film waste constituting the following percentages of polyolefin polymers (wt.%: LLDPE (46%, low density polyethylene (LDPE, 51%, high density polyethylene (HDPE, 1%, and polypropylene (PP, 2%. Compounded blends were evaluated for their mechanical and physical (optical properties. The impact of photodegradation on the formulated blends was studied, and loss of mechanical integrity was apparent with respect to both the exposure duration to weathering and waste content. The effect of processing conditions, namely, the die head temperature (DHT of the blown-film assembly used, was investigated in this work. It was witnessed that surpassing the melting point of the blends constituting polymers did not always result in a synergistic behaviour between polymers. This was suspected to be due to the loss of amorphous region that polyolefin polymers get subjected to with UV exposure under weathering conditions and the effect of the plastic waste constituents. The total change in colour (ΔE did not change with respect to DHT or waste content due to rapid change degradation on the material’s surface. Haze (% and light transmission (% decreased with the increase in waste content which was attributed to lack of miscibility between constituting polymers.

Degradation behavior of linear low density polyethylene by ultraviolet radiation exposition for agricultural applications

Energy Technology Data Exchange (ETDEWEB)

Poveda, Patricia N.S.; Silva, Leonardo G.A., E-mail: lgasilva@ipen.br, E-mail: patricianegrini@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Ciro, Rosemeire, E-mail: rosemeireciro@msn.com [Faculdades Oswaldo Cruz (FOC), Sao Paulo, SP (Brazil); Viana, Hamilton M., E-mail: hmviana@gmail.com [Centro Universitario Fundacao de Santo Andre (FSA/FAENG), Santo Andre, SP (Brazil)

2013-07-01

Polyethylene is the most important polymer used in agricultural applications. Polymers are susceptible to changes in their chemical structures that affect their mechanical properties under weather condition. In Polyethylene, photo-oxidation can occur because of impurities or chromophore groups (catalytic residue, mineral fillers, some commercial additives as stabilizers, lubricants, plasticizers, etc.). The critical ageing factors for greenhouse built with LDPE film are: total solar radiation, air temperature, relative humidity, mechanical stress, agrochemicals, air pollution, and combinations of these factors. Exposure of plastics to UV radiation causes a loss in their mechanical properties and/or change in appearance, including reduced ductility, color changes, yellowing and cracking. Additives are added to plastics to enhance the durability of the final product. Today, there are several additive systems (light stabilizers) developed to work according to resin, final application, type of cultivation, and other characteristics. The main types of light stabilizers are: UV absorbers, quenchers and free radicals scavengers. In addition to the conventional organic additives, some inorganic additives were obtained recently with the development of nanotechnology. This study evaluates the different additive systems (HALS, NPCC, nZnO and nTiO{sub 2}), applied 0.25% (in weight) in LLDPE. The samples were mixed by high rotation homogenizer and extrusion. Later, the samples were molded by injection and aged in QUV-B simulating 6 months of exposure to weather. Tests of FT-IR and tensile strength comparing to the non-aged samples were carried out in order to evaluate the performance of several additive systems concerning the degradation behavior of linear low density polyethylene. (author)

Degradation behavior of linear low density polyethylene by ultraviolet radiation exposition for agricultural applications

International Nuclear Information System (INIS)

Poveda, Patricia N.S.; Silva, Leonardo G.A.; Ciro, Rosemeire; Viana, Hamilton M.

2013-01-01

Polyethylene is the most important polymer used in agricultural applications. Polymers are susceptible to changes in their chemical structures that affect their mechanical properties under weather condition. In Polyethylene, photo-oxidation can occur because of impurities or chromophore groups (catalytic residue, mineral fillers, some commercial additives as stabilizers, lubricants, plasticizers, etc.). The critical ageing factors for greenhouse built with LDPE film are: total solar radiation, air temperature, relative humidity, mechanical stress, agrochemicals, air pollution, and combinations of these factors. Exposure of plastics to UV radiation causes a loss in their mechanical properties and/or change in appearance, including reduced ductility, color changes, yellowing and cracking. Additives are added to plastics to enhance the durability of the final product. Today, there are several additive systems (light stabilizers) developed to work according to resin, final application, type of cultivation, and other characteristics. The main types of light stabilizers are: UV absorbers, quenchers and free radicals scavengers. In addition to the conventional organic additives, some inorganic additives were obtained recently with the development of nanotechnology. This study evaluates the different additive systems (HALS, NPCC, nZnO and nTiO 2 ), applied 0.25% (in weight) in LLDPE. The samples were mixed by high rotation homogenizer and extrusion. Later, the samples were molded by injection and aged in QUV-B simulating 6 months of exposure to weather. Tests of FT-IR and tensile strength comparing to the non-aged samples were carried out in order to evaluate the performance of several additive systems concerning the degradation behavior of linear low density polyethylene. (author)

Characteristics of recycled and electron beam irradiated high density polyethylene samples

International Nuclear Information System (INIS)

Cardoso, Jessica R.; Gabriel, Leandro; Geraldo, Aurea B.C.; Moura, Eduardo

2015-01-01

Polymers modification by irradiation is a well-known process that allows degradation and cross-linking in concurrent events; this last is expected when an increase of mechanical properties is required. Actually, the interest of recycling and reuse of polymeric material is linked to the increase of plastics ending up in waste streams. Therefore, these both irradiation and recycling process may be conducted to allow a new use to this material that would be discarded by an improvement of its mechanical properties. In this work, the High Density Polyethylene (HDPE) matrix has been recycled five times from original substrate. The electron beam irradiation process was applied from 50 kGy to 200 kGy in both original and recycled samples; in this way, mechanical properties and thermal characteristics were evaluated. The results of applied process and material characterization are discussed. (author)

Characteristics of recycled and electron beam irradiated high density polyethylene samples

Energy Technology Data Exchange (ETDEWEB)

Cardoso, Jessica R.; Gabriel, Leandro; Geraldo, Aurea B.C.; Moura, Eduardo, E-mail: jrcardoso@ipen.br, E-mail: lgabriell@gmail.com, E-mail: ageraldo@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2015-07-01

Polymers modification by irradiation is a well-known process that allows degradation and cross-linking in concurrent events; this last is expected when an increase of mechanical properties is required. Actually, the interest of recycling and reuse of polymeric material is linked to the increase of plastics ending up in waste streams. Therefore, these both irradiation and recycling process may be conducted to allow a new use to this material that would be discarded by an improvement of its mechanical properties. In this work, the High Density Polyethylene (HDPE) matrix has been recycled five times from original substrate. The electron beam irradiation process was applied from 50 kGy to 200 kGy in both original and recycled samples; in this way, mechanical properties and thermal characteristics were evaluated. The results of applied process and material characterization are discussed. (author)

Characterization of injected linear low density polyethylene (LLDPE) irradiated by gamma-ray

International Nuclear Information System (INIS)

Oliveira, Ana C.F.; Parra, Duclerc F.; Ferreto, Helio F.R.; Lugao, Ademar B.

2013-01-01

The aim of this paper is to investigate of gamma irradiation effects on linear low density polyethylene (LLDPE) injected. Polymers processed by gamma radiation have new physical-chemical and mechanical properties. The ionizing radiation promotes chain scission and creates free radicals which can recombine, providing their annihilation, for crosslinking or branching. The polymer was irradiated with a source of 60 Co at doses of 5, 10, 20, 50 or 100 kGy at about 5 kGy s -1 rate, at room temperature. The changes in molecular structure of LLDPE were evaluated using melt flow index, gel fraction, differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FT-IR) and thermogravimetry analysis (TG). The results showed that the properties depend on dose irradiation. (author)

The improvement of polyethylene prostheses through radiation crosslinking

International Nuclear Information System (INIS)

Du Plessis, T.A.; Grobbelaar, C.J.; Marais, F.

1977-01-01

During the past decade, remarkable progress has been made in the utilization of high-density polyethylene (HDPE) as a material for the manufacture of prostheses used in orthopaedic operations. This polymer contributes largely to the success of total hip replacement. In the case of total knee replacement it was considered imperative that a more hard-wearing polymer should be developed if at all possible, because not only are the cold-flow characteristics of ordinary high-density polyethylene at high pressures a limiting factor, but particle formation from friction can furthermore lead to physiological side-effects which adversely affect the efficacy of joints made from this material, especially so in the case of knee-joints. Bearing in mind the excellent improvements to be obtained through the radiation crosslinking of polyethylene film, the radiation crosslinking of high-density polyethylene prostheses seemed to be a logical avenue to investigate. Experimental details are presented. Gamma radiation was used. Impact strength and tensile strength measurements were made on specimens irradiated over a dose range of 0 to 80 Mrad. The results are discussed. (U.K.)

Young Modulus of Crystalline Polyethylene from ab Initio Molecular Dynamics

NARCIS (Netherlands)

Hageman, J.C.L.; Meier, Robert J.; Heinemann, M.; Groot, R.A. de

1997-01-01

The Young modulus for crystalline polyethylene is calculated using ab initio molecular dynamics based on density functional theory in the local density approximation (DFT-LDA). This modulus, which can be seen as the ultimate value for the Young modulus of polyethylene fibers, is found to be 334 GPa.

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.

Atomistic simulation of CO 2 solubility in poly(ethylene oxide) oligomers

KAUST Repository

Hong, Bingbing

2013-10-02

We have performed atomistic molecular dynamics simulations coupled with thermodynamic integration to obtain the excess chemical potential and pressure-composition phase diagrams for CO2 in poly(ethylene oxide) oligomers. Poly(ethylene oxide) dimethyl ether, CH3O(CH 2CH2O)nCH3 (PEO for short) is a widely applied physical solvent that forms the major organic constituent of a class of novel nanoparticle-based absorbents. Good predictions were obtained for pressure-composition-density relations for CO2 + PEO oligomers (2 ≤ n ≤ 12), using the Potoff force field for PEO [J. Chem. Phys. 136, 044514 (2012)] together with the TraPPE model for CO2 [AIChE J. 47, 1676 (2001)]. Water effects on Henrys constant of CO2 in PEO have also been investigated. Addition of modest amounts of water in PEO produces a relatively small increase in Henrys constant. Dependence of the calculated Henrys constant on the weight percentage of water falls on a temperature-dependent master curve, irrespective of PEO chain length. © 2013 Taylor & Francis.

Study on polyethylene glycol/epoxy resin composite as a form-stable phase change material

International Nuclear Information System (INIS)

Fang Yutang; Kang Huiying; Wang Weilong; Liu Hong; Gao Xuenong

2010-01-01

Form-stable polyethylene glycol (PEG)/epoxy resin (EP) composite as a novel phase change material (PCM) was prepared using casting molding method. In this new material, PEG acts as the latent heat storage material and EP polymer serves as the supporting material, which provides structural strength and prevents the leakage of the melted PEG. The structure and morphology of the novel composite were observed using Fourier transformation infrared spectroscope (FTIR) and scanning electronic microscope (SEM). The thermo-mechanical property and transition behavior were characterized by polarizing optical microscope (POM), static thermo-mechanical analysis (TMA) and differential scanning calorimeter (DSC). The experimental results show that, as a result of the physical tangled function of the epoxy resin carrier to the PEG segment, the composite macroscopically presents the solid-solid phase change characteristic.

Heat shrinkable behavior, physico-mechanical and structure properties of electron beam cross-linked blends of high-density polyethylene with acrylonitrile-butadiene rubber

Science.gov (United States)

Reinholds, Ingars; Kalkis, Valdis; Merijs-Meri, Remo; Zicans, Janis; Grigalovica, Agnese

2016-03-01

In this study, heat-shrinkable composites of electron beam irradiated high-density polyethylene (HDPE) composites with acrylonitrile-butadiene rubber (NBR) were investigated. HDPE/NBR blends at a ratio of components 100/0, 90/10, 80/20, 50/50 and 20/80 wt% were prepared using a two-roll mill. The compression molded films were irradiated high-energy (5 MeV) accelerated electrons up to irradiation absorbed doses of 100-300 kGy. The effect of electron beam induced cross-linking was evaluated by the changes of mechanical properties, gel content and by the differences of thermal properties, detected by differential scanning calorimetry. The thermo-shrinkage forces were determined as the kinetics of thermorelaxation and the residual shrinkage stresses of previously oriented (stretched up to 100% at above melting temperature of HDPE and followed by cooling to room temperature) specimens of irradiated HDPE/NBR blends under isometric heating-cooling mode. The compatibility between the both components was enhanced due to the formation of cross-linked sites at amorphous interphase. The results showed increase of mechanical stiffness of composites with increase of irradiation dose. The values of gel fraction compared to thermorelaxation stresses increased with the growth of irradiation dose level, as a result of formation cross-linked sites in amorphous PP/NBR interphase.

Changes in mechanical properties due to gamma irradiation of high-density polyethylene (HDPE

Directory of Open Access Journals (Sweden)

S. S. Cota

2007-06-01

Full Text Available This paper presents an experimental analysis of the effect of dose and dose rate parameters during gamma irradiation of high-density polyethylene (HDPE samples. Considerations concerning the influence of these parameters on HDPE mechanical strength properties as a result of the predominance of oxidative degradation or of cross-linking are presented. The experimental results show an improvement of HDPE mechanical strength as dose increases, indicating the predominance of cross-linking over oxidative degradation and that lower doses are necessary to obtain a similar change in resistance parameters when radiation is applied at lower dose rates, showing that gamma radiation affects the HDPE in a more efficient way at lower dose rates.

Changes in mechanical properties due to gamma irradiation of high-density polyethylene (HDPE)

International Nuclear Information System (INIS)

Cota, S.S.; Vasconcelos, V.; Senne Junior, M.; Carvalho, L.L.; Rezende, D.B.; Correa, R.F.

2007-01-01

This paper presents an experimental analysis of the effect of dose and dose rate parameters during gamma irradiation of high-density polyethylene (HDPE) samples. Considerations concerning the influence of these parameters on HDPE mechanical strength properties as a result of the predominance of oxidative degradation or of cross-linking are presented. The experimental results show an improvement of HDPE mechanical strength as dose increases, indicating the predominance of cross-linking over oxidative degradation and that lower doses are necessary to obtain a similar change in resistance parameters when radiation is applied at lower dose rates, showing that gamma radiation affects the HDPE in a more efficient way at lower dose rates. (author)

Oil-Impregnated Polyethylene Films

Science.gov (United States)

Mukherjee, Ranit; Habibi, Mohammad; Rashed, Ziad; Berbert, Otacilio; Shi, Shawn; Boreyko, Jonathan

2017-11-01

Slippery liquid-infused porous surfaces (SLIPS) minimize the contact angle hysteresis of a wide range of liquids and aqueous food products. Although hydrophobic polymers are often used as the porous substrate for SLIPS, the choice of polymer has been limited to silicone-based or fluorine-based materials. Hydrocarbon-based polymers, such as polyethylene, are cost effective and widely used in food packaging applications where SLIPS would be highly desirable. However, to date there have been no reports on using polyethylene as a SLIPS substrate, as it is considered highly impermeable. Here, we show that thin films of low-density polyethylene can be stably impregnated with carbon-based oils without requiring any surface modification. Wicking tests reveal that oils with sufficient chemical compatibility follow Washburn's equation. The nanometric effective pore size of the polyethylene does result in a very low wicking speed, but by using micro-thin films and a drawdown coater, impregnation can still be completed in under one second. The oil-impregnated polyethylene films promoted ultra-slippery behavior for water, ketchup, and yogurt while remaining durable even after being submerged in ketchup for over one month. This work was supported by Bemis North America (AT-23981).

Thermomechanical behaviour of stabilized polyethylene irradiated with gamma rays

Energy Technology Data Exchange (ETDEWEB)

Novakovic, Lj; Markovic, V; Gal, O; Stannett, V T

1986-01-01

The moduli of elasticity at 150/sup 0/C for irradiated linear low density and low density polyethylenes, pure and with 0.5% antioxidants were determined using the penetration technique. Simultaneously, on similar samples, the gel content was measured. Analysing the radiation parameters and comparing data derived from the two methods the efficiency of radiation crosslinking of different polyethylenes and the effect of antioxidants is discussed.

Thermomechanical behaviour of stabilized polyethylene irradiated with gamma rays

International Nuclear Information System (INIS)

Novakovic, Lj.; Markovic, V.; Gal, O.; Stannett, V.T.

1986-01-01

The moduli of elasticity at 150 C for irradiated linear low density and low density polyethylenes, pure and with 0.5% antioxidants were determined using the penetration technique. Simultaneously, on similar samples, the gel content was measured. Analysing the radiation parameters and comparing data derived from the two methods the efficiency of radiation crosslinking of different polyethylenes and the effect of antioxidants is discussed. (author)

Wet self-cleaning of superhydrophobic microfiber adhesives formed from high density polyethylene.

Science.gov (United States)

Lee, Jongho; Fearing, Ronald S

2012-10-30

Biologically inspired adhesives developed for switchable and controllable adhesion often require repetitive uses in general, dirty, environments. Superhydrophobic microstructures on the lotus leaf lead to exceptional self-cleaning of dirt particles on nonadhesive surfaces with water droplets. This paper describes the self-cleaning properties of a hard-polymer-based adhesive formed with high-aspect-ratio microfibers from high-density polyethylene (HDPE). The microfiber adhesive shows almost complete wet self-cleaning of dirt particles with water droplets, recovering 98% of the adhesion of the pristine microfiber adhesives. The low contact angle hysteresis indicates that the surface of microfiber adhesives is superhydrophobic. Theoretical and experimental studies reveal a design parameter, length, which can control the adhesion without affecting the superhydrophobicity. The results suggest some properties of biologically inspired adhesives can be controlled independently by adjusting design parameters.

Thermal and optical excitation of trapped electrons in high-density polyethylene (HDPE) studied through positron annihilation

International Nuclear Information System (INIS)

Nahid, F.; Zhang, J.D.; Yu, T.F.; Ling, C.C.; Fung, S.; Beling, C.D.

2011-01-01

Positronium (Ps) formation in high-density polyethylene (HDPE) has been studied below the glass transition temperature. The formation probability increases with positron irradiation time due to an increasing number of inter-track trapped electrons becoming available for positron capture. The temperature variation of the saturated Ps level is discussed in different models. The quenching of trapped electrons by light has been studied and the optical de-trapping cross-section for different photon energies has been estimated over the visible region.

Swift heavy ion irradiation effects on carbonyl and trans-vinylene groups in high and low density polyethylene

International Nuclear Information System (INIS)

Grosso, M.F. del; Chappa, V.C.; Arbeitman, C.R.; Garcia Bermudez, G.; Behar, M.

2009-01-01

In this work, we have studied the effects of swift heavy ion irradiation on the creation of new functional groups in high and low density polyethylene (HDPE and LDPE). Polymers were irradiated with different ions (6.77 MeV He and 47 MeV Li) and fluences. The induced changes were analyzed by Fourier transform infrared (FTIR) spectroscopy. Creation and damage cross sections for some groups were compared for two different types of PE.

Swift heavy ion irradiation effects on carbonyl and trans-vinylene groups in high and low density polyethylene

Energy Technology Data Exchange (ETDEWEB)

Grosso, M.F. del, E-mail: delgrosso@tandar.cnea.gov.a [Gerencia de Investigacion y Aplicaciones, TANDAR-CNEA (Argentina); Chappa, V.C. [Gerencia de Investigacion y Aplicaciones, TANDAR-CNEA (Argentina); CONICET (Argentina); Arbeitman, C.R. [Gerencia de Investigacion y Aplicaciones, TANDAR-CNEA (Argentina); Garcia Bermudez, G. [Gerencia de Investigacion y Aplicaciones, TANDAR-CNEA (Argentina); CONICET (Argentina); Escuela de Ciencia y Tecnologia, UNSAM (Argentina); Behar, M. [Instituto de Fisica, UFRGS, Porto Alegre (Brazil)

2009-10-01

In this work, we have studied the effects of swift heavy ion irradiation on the creation of new functional groups in high and low density polyethylene (HDPE and LDPE). Polymers were irradiated with different ions (6.77 MeV He and 47 MeV Li) and fluences. The induced changes were analyzed by Fourier transform infrared (FTIR) spectroscopy. Creation and damage cross sections for some groups were compared for two different types of PE.

Experimental investigation of the effect of titanium dioxide and barium titanate additives on DC transient currents in low density polyethylene

DEFF Research Database (Denmark)

Khalil, M.S; Henk, Peter O; Henriksen, Mogens

1988-01-01

The effect of titanium dioxide as a semiconductive additive and barium titanate as a highly polar additive on the DC transient currents in low-density polyethylene is investigated. Experiments were made using thick specimens under a high electric field (>25×106 V/m) and a constant temperature of 40...

THE ANALYSIS OF PARTIAL DISCHARGE (PD FROM ELECTRICAL TREEING IN LINEAR LOW DENSITY POLYETHYLENE (LLDPE AND HIGH DENSITY POLYETHYLENE (HDPE

Directory of Open Access Journals (Sweden)

Hermawan Hermawan

2012-02-01

Full Text Available Recently, the transmission of electric energy has been developed by insulated cable. The suitable materialas an insulated cable is LLDPE and HDPE. In order to understand the quality of insulation system, themeasuring of PD has done. PD could begin completely insulation failure (breakdown. Therefore, it is veryimportant to understand the characteristic of PD and the enclose event on it, because PD is a main factorwhich caused insulation failure.This paper presents the result of PD measurement in the laboratory that used needle-plane electrode. Itwas supported by equipments such as osiloskop Digital GDS 2104 GW Instek, HPF, and RC detector.Polymer sample that used in this research is LLDPE (Linier Low Density Polyethylene and HDPE with 20x 4 x 25 mm3 dimension in each. Needle was made by steel (length 50 mm and diameter 1.15 mm, it wasstick to the polymer material. The distance between needle to the plane is 5 mm. The applied voltage foreach sample was 16 kVrms, 18 kVrms, 20 kVrms and 22 kVrms. The Taking of PD data was done in thefirst minute, 10th minute, 20th and so on until 180th minute.The measurement result shows that the characteristic of PD number and maximum charge as a function oftime and as a function of applied voltage inclined increasing both on LLDPE and HDPE. But, PD intensityin HDPE is higher than LLDPE.

Study of the formation of polyethylene composites and lignocellulose materials by means of irradiation and extrusion

International Nuclear Information System (INIS)

Azevedo, Marcos Bertrand de; Romero, Guillermo R.; Gonzalez, Maria Elisa; Smolko, Eduardo E.

2000-01-01

One of the greatest opportunities for using of biomass as a precursor in the production of polymeric materials is the lignocellulose composites that can combine high performance with low costs. This work is a initial study on the production of a lignocellulose reinforced polyethylene composite. A compatibilization made by a induced gamma radiation grafting reaction was used to increase the adhesion between the matrix and the reinforced or filled fibers. The lignocellulose materials were exposed to gamma radiation in order to promote a molecular degradation and increase its reactivity. The polymer, the lignocellulose material and the compatibilization were processed by extrusion and the composite produced by this process were characterized by mechanical tests. (author)

Tensile mechanical response of polyethylene – clay nanocomposites.

Directory of Open Access Journals (Sweden)

2007-03-01

Full Text Available In this work we report on the microstructural and the mechanical characteristics of high density polyethylene (HDPE-clay nanocomposites, with particular attention to the creep behaviour. The samples were prepared through melt compounding, using two high-density polyethylenes with different melt flow rate (MFR, two different organo-modified clays, and changing the relative amount of a polyethylene grafted with maleic anhydride (PEgMA compatibilizer. The intercalation process is more effective as the matrix melt viscosity decreases (higher MFR, while the clay interlamellar spacing increases as the compatibilizer amount increases. The relative stiffness of the nanocomposites increases with the addition of clay, with a limited enhancement of the relative yield stress. The better intercalation obtained by the addition of the compatibilizer is not accompanied by a concurrent improvement of the tensile mechanical properties. The creep resistance is enhanced by the introduction of clay, with an appreciable dependence on both the polyethylene and the clay type.

Investigation on the effect of formulation and process variables of Polyethylene Foams Production

International Nuclear Information System (INIS)

Barikani, H.; Sarai, M.

2001-01-01

Polyolefin foams such as polyethylene, polypropylene and their copolymers have been extensively used in packaging, automotive, military, marine, cable industries and sports, due to their unique properties namely: light weight, chemical resistance, thermal insulation, inertness, abrasion resistance, buoyancy and low cost. With regards to domestic mass production of polyethylene, replacement of polyurethane with polyethylene foam is very important in some applications from economical point of view. In this research preparation of high density and low density polyethylene foams were studied and the effect of formulation factors such as blowing agent, cross-linker, calcium carbonate, zinc oxide and processing factors such as heat, pressure and reaction time on density and cell size were investigated

Catalytic co-pyrolysis of paper biomass and plastic mixtures (HDPE (high density polyethylene), PP (polypropylene) and PET (polyethylene terephthalate)) and product analysis

International Nuclear Information System (INIS)

Chattopadhyay, Jayeeta; Pathak, T.S.; Srivastava, R.; Singh, A.C.

2016-01-01

Catalytic co-pyrolysis of biomass and plastics (HDPE (high density polyethylene), PP (polypropylene) and PET (polyethylene terephthalate)) has been performed in a fixed-bed reactor in presence of cobalt based alumina, ceria and ceria-alumina catalysts to analyze the product distribution and selectivity. Catalysts are synthesized using co-precipitation method and characterized by BET (Brunauer–Emmett–Teller) surface area and XRD analysis. The effect of catalytic co-pyrolysis at different temperature with product distribution has been evaluated. The results have clearly shown the synergistic effect between biomass and plastics, the liquid products gradually increases forming with rise in the plastic content in the blend. Gaseous products have yielded most during pyrolysis of blend having biomass/plastics ratio of 5:1 with the presence of 40% Co/30% CeO_2/30% Al_2O_3 catalyst with hydrogen gas production touched its peak of 47 vol%. Catalytic performance enhanced with increase with the cobalt loading, with best performance attributing to 40% Co/30% CeO_2/30% Al_2O_3 catalyst. - Highlights: • Catalytic co-pyrolysis of biomass and plastics (HDPE, PP & PET) blends in fixed-bed reactor. • Strong synergistic effect evident between biomass and plastics. • Solid residue diminished with application of catalysts. • Aromatics and olefins production increases with higher plastic content. • More hydrogen production with application of catalysts with higher cobalt content.

Process for producing chlorinated polyethylene

International Nuclear Information System (INIS)

Nose, Shinji; Takayama, Shin-ichi; Kodama, Takashi.

1970-01-01

A process for chlorinated polyethylene by the chlorination of an aqueous suspension of polyethylene without the use catalysts is given, using 5-55% by gel content of cross-linked polyethylene powders. The products have favorable material workability, transparency, impact strength and tensile properties. In the case of peroxide cross-linking, a mixture of peroxides with polyethylene must be ground after heat treatment. The polyethylene may preferably have a gel content of 5-55%. The chlorination temperature may be 40 0 C or more, preferably 60 0 to 160 0 C. In one example, high pressure polymerized fine polyethylene powders of 15μ having a density of 0.935 g/cc, a softening point of 114 0 C, an average molecular weight of 35,000 were irradiated in air with 40 Mrad electron beams from a 2 MV Cockcroft-Walton type accelerator at room temperature. The thus irradiated polyethylene had a gel content of 55% and a softening point of 119 0 C. It was chlorinated upto a chlorine content of 33% at 100 0 C. Products were white crystals having a melting point of 122 0 C and a melting heat value of 32 mcal/mg. A sheet formed from this product showed a tensile strength of 280 kg/cm 2 , an elongation of 370% and a hardness of 90. (Iwakiri, K.)

Effect of degrading yellow oxo-biodegradable low-density polyethylene films to water quality

Science.gov (United States)

Requejo, B. A.; Pajarito, B. B.

2017-05-01

Polyethylene (PE) contributes largely to plastic wastes that are disposed in aquatic environment as a consequence of its widespread use. In this study, yellow oxo-biodegradable low-density PE films were immersed in deionized water at 50°C for 49 days. Indicators of water quality: pH, oxidation-reduction potential, turbidity, and total dissolved solids (TDS), were monitored at regular intervals. It was observed that pH initially rises and then slowly decreases with time, oxidation-reduction potential decreases then slowly increases with time, turbidity rises above the control at varied rates, and TDS increases abruptly and rises at a hindered rate. Moreover, the films potentially leach out lead chromate. The results imply that degrading oxo-biodegradable LDPE films results to significant reduction of water quality.

Phase Behavior of Blends of Linear and Branched Polyethylenes on Micron-Length Scales via Ultra-Small-Angle Neutron Scattering (USANS)

International Nuclear Information System (INIS)

Agamalian, M.M.; Alamo, R.G.; Londono, J.D.; Mandelkern, L.; Wignall, G.D.

1999-01-01

SANS experiments on blends of linear, high density (HD) and long chain branched, low density (LD) polyethylenes indicate that these systems form a one-phase mixture in the melt. However, the maximum spatial resolution of pinhole cameras is approximately equal to 10 3 and it has therefore been suggested that data might also be interpreted as arising from a bi-phasic melt with large a particle size ( 1 m), because most of the scattering from the different phases would not be resolved. We have addressed this hypothesis by means of USANS experiments, which confirm that HDPEILDPE blends are homogenous in the melt on length scales up to 20 m. We have also studied blends of HDPE and short-chain branched linear low density polyethylenes (LLDPEs), which phase separate when the branch content is sufficiently high. LLDPEs prepared with Ziegler-Natta catalysts exhibit a wide distribution of compositions, and may therefore be thought of as a blend of different species. When the composition distribution is broad enough, a fraction of highly branched chains may phase separate on m-length scales, and USANS has also been used to quantify this phenomenon

Durability of a fin-tube latent heat storage using high density polyethylene as PCM

Science.gov (United States)

Zauner, Christoph; Hengstberger, Florian; Etzel, Mark; Lager, Daniel; Hofmann, Rene; Walter, Heimo

2017-10-01

Polymers have rarely been used as storage materials in latent heat storages up to now. Thus, we systematically screened all polymers available on a large-scale, selected promising ones based on their theoretical properties and experimentally tested more than 50 candidates. We found that polyethylene, polyoxymethylene and polyamides are promising even as recycled material. Especially high density polyethylene (HDPE) turned out to be suitable as was shown by detailed thermophysical characterization including more than 1000 heating and cooling cycles for INEOS Rigidex HD6070EA. We built a storage with 170 kg HDPE and a total mass of 600 kg based on a fin-tube heat exchanger and characterized its energy capacity, power characteristics and temperature profiles using a thermal oil test rig. In total we performed 30 melting and crystallization cycles where the whole storage was above 100 °C for more than 140 hours. After usage we examined the interior of the storage by cutting it into various pieces. A thin layer of degradation was observed on the surfaces of the PCM which is most likely related to thermo-oxidative degeneration of HDPE. However, the bulk of the PCM is still intact as well as the heat exchanger itself.

Biodegradation of low-density polyethylene (LDPE by mixed culture of Lysinibacillus xylanilyticus and Aspergillus niger in soil.

Directory of Open Access Journals (Sweden)

Atefeh Esmaeili

Full Text Available In this study, two strains of Aspergillus sp. and Lysinibacillus sp. with remarkable abilities to degrade low-density polyethylene (LDPE were isolated from landfill soils in Tehran using enrichment culture and screening procedures. The biodegradation process was performed for 126 days in soil using UV- and non-UV-irradiated pure LDPE films without pro-oxidant additives in the presence and absence of mixed cultures of selected microorganisms. The process was monitored by measuring the microbial population, the biomass carbon, pH and respiration in the soil, and the mechanical properties of the films. The carbon dioxide measurements in the soil showed that the biodegradation in the un-inoculated treatments were slow and were about 7.6% and 8.6% of the mineralisation measured for the non-UV-irradiated and UV-irradiated LDPE, respectively, after 126 days. In contrast, in the presence of the selected microorganisms, biodegradation was much more efficient and the percentages of biodegradation were 29.5% and 15.8% for the UV-irradiated and non-UV-irradiated films, respectively. The percentage decrease in the carbonyl index was higher for the UV-irradiated LDPE when the biodegradation was performed in soil inoculated with the selected microorganisms. The percentage elongation of the films decreased during the biodegradation process. The Fourier transform infra-red (FT-IR, x-ray diffraction (XRD and scanning electron microscopy (SEM were used to determine structural, morphological and surface changes on polyethylene. These analyses showed that the selected microorganisms could modify and colonise both types of polyethylene. This study also confirmed the ability of these isolates to utilise virgin polyethylene without pro-oxidant additives and oxidation pretreatment, as the carbon source.

Biodegradation of Low-Density Polyethylene (LDPE) by Mixed Culture of Lysinibacillus xylanilyticus and Aspergillus niger in Soil

Science.gov (United States)

Esmaeili, Atefeh; Pourbabaee, Ahmad Ali; Alikhani, Hossein Ali; Shabani, Farzin; Esmaeili, Ensieh

2013-01-01

In this study, two strains of Aspergillus sp. and Lysinibacillus sp. with remarkable abilities to degrade low-density polyethylene (LDPE) were isolated from landfill soils in Tehran using enrichment culture and screening procedures. The biodegradation process was performed for 126 days in soil using UV- and non-UV-irradiated pure LDPE films without pro-oxidant additives in the presence and absence of mixed cultures of selected microorganisms. The process was monitored by measuring the microbial population, the biomass carbon, pH and respiration in the soil, and the mechanical properties of the films. The carbon dioxide measurements in the soil showed that the biodegradation in the un-inoculated treatments were slow and were about 7.6% and 8.6% of the mineralisation measured for the non-UV-irradiated and UV-irradiated LDPE, respectively, after 126 days. In contrast, in the presence of the selected microorganisms, biodegradation was much more efficient and the percentages of biodegradation were 29.5% and 15.8% for the UV-irradiated and non-UV-irradiated films, respectively. The percentage decrease in the carbonyl index was higher for the UV-irradiated LDPE when the biodegradation was performed in soil inoculated with the selected microorganisms. The percentage elongation of the films decreased during the biodegradation process. The Fourier transform infra-red (FT-IR), x-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to determine structural, morphological and surface changes on polyethylene. These analyses showed that the selected microorganisms could modify and colonise both types of polyethylene. This study also confirmed the ability of these isolates to utilise virgin polyethylene without pro-oxidant additives and oxidation pretreatment, as the carbon source. PMID:24086254

DC Thermal Plasma Design and Utilization for the Low Density Polyethylene to Diesel Oil Pyrolysis Reaction

Directory of Open Access Journals (Sweden)

Hossam A. Gabbar

2017-06-01

Full Text Available The exponential increase of plastic production produces 100 million tonnes of waste plastics annually which could be converted into hydrocarbon fuels in a thermal cracking process called pyrolysis. In this research work, a direct current (DC thermal plasma circuit is designed and used for conversion of low density polyethylene (LDPE into diesel oil in a laboratory scale pyrolysis reactor. The experimental setup uses a 270 W DC thermal plasma at operating temperatures in the range of 625 °C to 860 °C for a low density polyethylene (LDPE pyrolysis reaction at pressure = −0.95, temperature = 550 °C with τ = 30 min at a constant heating rate of 7.8 °C/min. The experimental setup consists of a vacuum pump, closed system vessel, direct current (DC plasma circuit, and a k-type thermocouple placed a few millimeters from the reactant sample. The hydrocarbon products are condensed to diesel oil and analyzed using flame ionization detector (FID gas chromatography. The analysis shows 87.5% diesel oil, 1,4-dichlorobenzene (Surr, benzene, ethylbenzene and traces of toluene and xylene. The direct current (DC thermal plasma achieves 56.9 wt. % of diesel range oil (DRO, 37.8 wt. % gaseous products and minimal tar production. The direct current (DC thermal plasma shows reliability, better temperature control, and high thermal performance as well as the ability to work for long operation periods.

Self-sensing performance of MWCNT-low density polyethylene nanocomposites

Science.gov (United States)

Gupta, Tejendra K.; Kumar, S.; Khan, Amal Z.; Varadarajan, Kartik M.; Cantwell, Wesley J.

2018-01-01

Carbon nanotubes (CNTs) based polymer nanocomposites offer a range of remarkable properties. Here, we demonstrate self-sensing performance of low density polyethylene (LDPE)-multiwalled carbon nanotubes (MWCNTs) nanocomposites for the first time. The dispersion of the CNTs and the morphology of the nanocomposites was investigated using scanning electron microscopy, x-ray diffraction and Raman spectroscopic techniques. The thermal properties were measured using thermal gravimetric analysis and differential scanning calorimetry and were found to increase with increasing wt% of MWCNTs in LDPE matrix. An overall improvement in ultimate tensile strength, yield strength and Young’s modulus was found to be 59.6%, 48.5% and 129.3%, respectively for 5.0 wt% loading of MWCNTs. The electrical percolation threshold was observed at 1.0 wt% of MWCNTs and the highest electrical conductivity of 2.8 × 10-2 Scm-1 was observed at 5.0 wt% loading of MWCNTs. These piezo-resistive nanocomposites offer tunable self-sensing capabilities with gauge factors in the ranges of 17-52 and 42-530 in linear elastic (strain ˜3%) and inelastic regimes (strain ˜15%) respectively. Our demonstration would provide guidelines for the fabrication of low cost, self-sensing MWCNT-LDPE nanocomposites for potential use as civil water pipelines and landfill membranes.

Cementitious building material incorporating end-capped polyethylene glycol as a phase change material

Science.gov (United States)

Salyer, Ival O.; Griffen, Charles W.

1986-01-01

A cementitious composition comprising a cementitious material and polyethylene glycol or end-capped polyethylene glycol as a phase change material, said polyethylene glycol and said end-capped polyethylene glycol having a molecular weight greater than about 400 and a heat of fusion greater than about 30 cal/g; the compositions are useful in making pre-formed building materials such as concrete blocks, brick, dry wall and the like or in making poured structures such as walls or floor pads; the glycols can be encapsulated to reduce their tendency to retard set.

Preparation of Basalt Incorporated Polyethylene Composite with Enhanced Mechanical Properties for Various Applications

Directory of Open Access Journals (Sweden)

Bredikhin Pavel

2017-01-01

Full Text Available The present article showed the possibility of increasing the complex of mechanical properties of polyolefins with dispersed mineral fillers obtained by fine grinding of basalt rocks via ball mill processing. The composites based on dispersed basalt, which were derived from Samara rock mass (Russia with rare earth elements containing, were obtained by extrusion combining the binder and filler, followed by preparation injection-molded test samples. The study of mechanical properties of materials developed showed the possibility of a significant increase in strength characteristics of different types of polyethylene: the breaking stress at static bending for HDPE can be increasing more than 60% and the impact strength by more than 4 times. In addition the incorporation of the dispersed basalt also enhanced the thermal properties of the composites (the oxygen index of HDPE increases from 19 to 25%.

Radiation-modified blends of the basis of polyethylene terephthalate and polypropylene

International Nuclear Information System (INIS)

Mery-Meri, R.; Revyakin, O.; Zicans, J.

2000-01-01

The binary composite systems on the basis of post-consumer poly-(ethylene terephthalate) and polypropylene have been investigated. Mechanical properties of the compositions were studied in detail in order to expand the application possibilities of tested binary composites. Structural changes of the poly (ethylene terephthalate) / polypropylene blends depending on the concentration of the components were investigated also. Additionally, the optimum processing conditions were established. Particular attention was paid to study the influence of the ionizing γ-radiation on the structural and mechanical properties of the composition systems tested. The magnitude of the adsorbed dose od γ-radiation was established to affect differently the structure of poly(ethylene terephalate) and polypropylene. At small absorbed doses (50 kGy) crosslinking of the polymer was observed for both poly(ethylene terephthalate) and polypropylene resulting in the increase of some mechanical properties of pure materials as well of their compositions, whereas the absorbed dose of 300 kGy caused the destruction of the tested materials. It is important to mention that the rate of radiation-chemical destruction of polypropylene is higher than poly(ethylene terephthalate) destruction rate. (author)

Decoration of multi-walled carbon nanotubes by polymer wrapping and its application in MWCNT/polyethylene composites.

Science.gov (United States)

Hsiao, An-En; Tsai, Shu-Ya; Hsu, Mei-Wen; Chang, Shinn-Jen

2012-05-06

We dispersed the non-covalent functionalization of multi-walled carbon nanotubes (CNTs) with a polymer dispersant and obtained a powder of polymer-wrapped CNTs. The UV-vis absorption spectrum was used to investigate the optimal weight ratio of the CNTs and polymer dispersant. The powder of polymer-wrapped CNTs had improved the drawbacks of CNTs of being lightweight and difficult to process, and it can re-disperse in a solvent. Then, we blended the polymer-wrapped CNTs and polyethylene (PE) by melt-mixing and produced a conductive masterbatch and CNT/PE composites. The polymer-wrapped CNTs showed lower surface resistivity in composites than the raw CNTs. The scanning electron microscopy images also showed that the polymer-wrapped CNTs can disperse well in composites than the raw CNTs.

Degradation assessment of natural weathering on low density polyethylene/thermoplastic soya spent powder blends

Science.gov (United States)

Nuradibah, M. A.; Sam, S. T.; Noriman, N. Z.; Ragunathan, S.; Ismail, H.

2015-07-01

Soya spent powder was blended with low density polyethylene (LDPE) ranging from 5-25 wt%. Glycerol was added to soya spent powder (SSP) for preparation of thermoplastic soya spent powder (TSSP). Then, the blends were exposed to natural weathering for 6 months. The susceptibility of the LDPE/soya spent powder blends based on its tensile, morphological properties and structural changes was measured every three months. The tensile strength of LDPE/TSSP blends after 6 months of weathering was the lowest compared to the other blends whereas LDPE/SSP blends after 6 months of weathering demonstrated the lowest elongation at break (Eb). Large pore can be seen on the surface of 25 wt% of LDPE/SSP blends.

Investigation of space charge distribution of low-density polyethylene/GO-GNF (graphene oxide from graphite nanofiber) nanocomposite for HVDC application.

Science.gov (United States)

Kim, Yoon Jin; Ha, Son-Tung; Lee, Gun Joo; Nam, Jin Ho; Ryu, Ik Hyun; Nam, Su Hyun; Park, Cheol Min; In, Insik; Kim, Jiwan; Han, Chul Jong

2013-05-01

This paper reported a research on space charge distribution in low-density polyethylene (LDPE) nanocomposites with different types of graphene and graphene oxide (GO) at low filler content (0.05 wt%) under high DC electric field. Effect of addition of graphene oxide or graphene, its dispersion in LDPE polymer matrix on the ability to suppress space charge generation will be investigated and compared with MgO/LDPE nanocomposite at the same filler concentration. At an applied electric field of 80 kV/mm, a positive packet-like charge was observed in both neat LDPE, MgO/LDPE, and graphene/LDPE nanocomposites, whereas only little homogenous space charge was observed in GO/LDPE nanocomposites, especially with GO synthesized from graphite nano fiber (GNF) which is only -100 nm in diameter. Our research also suggests that dispersion of graphene oxide particles on the polymer matrix plays a significant role to the performance of nanocomposites on suppressing packet-like space charge. From these results, it is expected that nano-sized GO synthesized from GNF can be a promising filler material to LDPE composite for HVDC applications.

Thermoplastic elastomers blends based on linear low density polyethylene, ethylene-1-octene copolymers and ground rubber tire

Directory of Open Access Journals (Sweden)

Marisa Cristina Guimarães Rocha

2014-01-01

Full Text Available Blends of linear low density polyethylene (LLDPE ethylene-1-octene copolymers (EOC, with different 1-octene (OC content, and ground rubber tire (GRT were prepared by melt mixing in a twin screw extruder. Five different compositions of LLDPE/EOC/GRT blends were processed in the extruder to evaluate the effect of EOC addition to the LLDPE/GRT blends. The addition of EOC to LLDPE/GRT blends improves the mechanical properties. Besides, the replacement of 5% of GRT by EOC grades (OC = 20 or 30 wt % in the 50/50 LLDPE/GRT blend, leads to a significant increase of ultimate tensile properties. The EOC comonomer content affects the properties of LLDPE/EOC and LLDPE/EOC/GRT blends. Dynamical-mechanical analyses showed that, with the addition of EOC to LLDPE/GRT blends, the Tg of GRT and the Tg of EOC are closer. This effect is more pronounced when the EOC with the highest content of comonomer (30 wt % is added to LLDPE/GRT blend. In this case, only one peak related to the Tg of the rubber phase can be visualized in the amorphous region. These findings indicate that EOC may act as compatibilizer agent for LLDPE/GRT blends.

Fabrication of a Nano-ZnO/Polyethylene/Wood-Fiber Composite with Enhanced Microwave Absorption and Photocatalytic Activity via a Facile Hot-Press Method

Directory of Open Access Journals (Sweden)

Baokang Dang

2017-11-01

Full Text Available A polyethylene/wood-fiber composite loaded with nano-ZnO was prepared by a facile hot-press method and was used for the photocatalytic degradation of organic compounds as well as for microwave absorption. ZnO nanoparticles with an average size of 29 nm and polyethylene (PE powders were dispersed on the wood fibers’ surface through a viscous cationic polyacrylamide (CPAM solution. The reflection loss (RL value of the resulting composite was −21 dB, with a thickness of 3.5 mm in the frequency of 17.17 GHz. The PE/ZnO/wood-fiber (PZW composite exhibited superior photocatalytic activity (84% methyl orange degradation within 300 min under UV light irradiation. ZnO nanoparticels (NPs increased the storage modulus of the PZW composite, and the damping factor was transferred to the higher temperature region. The PZW composite exhibited the maximum flexural strength of 58 MPa and a modulus of elasticity (MOE of 9625 MPa. Meanwhile, it also displayed dimensional stability (thickness swelling value of 9%.

Interfacial stick–slip transition in hydroxyapatite filled high density ...

Indian Academy of Sciences (India)

Unknown

flow curves of composites and that of unfilled system remain identical. Filler addition lowers the .... Injection moulding grade high density polyethylene,. HD6070EA, was ... rheometer (Rosand Precision Ltd., UK) using version. 6⋅10 software. .... Bagley E B, Cabbot I M and West D C 1958 J. Appl. Phys. 29. 109. Blyler L L and ...

Study of gamma irradiated polyethylenes by temperature modulated differential scanning calorimetry

International Nuclear Information System (INIS)

Secerov, B.; Galovic, S.; Trifunovic, S.; Milicevic, D.; Suljovrujic, E.

2011-01-01

Complete text of publication follows. The various polyethylenes (PEs) and effects of high energy radiation on theirs structures were widely studied in the past using conventional Differential Scanning Calorimetry (DSC) measurements. In this work, we applied the Temperature Modulated Differential Scanning Calorimetry (TMDSC) technique in order to obtain more information about the influence of initial structural differences and gamma radiation on the evolution in structure and thermal properties of different polyethylenes. For this reason, low density polyethylene (LDPE), linear low density polyethylene (LLDPE) and high density polyethylene (HDPE) samples were exposed to gamma radiation, in air, to a wide range of absorbed doses (up to 2400 kGy). The separation of the total heat flow TMDSC signal into a reversing and nonreversing part enabled to observed the low temperature enthalpy relaxation (related to the existence of the 'rigid amorphous phase') and recrystallization processes as well as to follow their and/or radiation-induced evolution of melting in a more revealing manner compared to the case of the conventional DSC. Consequently, our results indicate that TMDSC could improve the understanding of radiation-induced effects in polymers.

Poly(ethylene oxide)/poly(butylene terephthalate) segmented block copolymers: the effect of copolymer composition on physical properties and degradation behavior

NARCIS (Netherlands)

Deschamps, A.A.; Grijpma, Dirk W.; Feijen, Jan

2001-01-01

In this study, the influence of copolymer composition on the physical properties and the degradation behavior of thermoplastic elastomers based on poly(ethylene oxide) (PEO) and poly(butylene terephthalate) (PBT) segments is investigated. These materials are intended to be used in medical

Dynamic adsorption of mixtures of Rhodamine B, Pb (II), Cu (II) and Zn(II) ions on composites chitosan-silica-polyethylene glycol membrane

Science.gov (United States)

Mahatmanti, F. W.; Rengga, W. D. P.; Kusumastuti, E.; Nuryono

2018-04-01

The adsorption of a solution mixture of Rhodamine B, Pb (II), Cu (II) and Zn(II) was studied using dynamic methods employing chitosan-silica-polyethylene glycol (Ch/Si/P) composite membrane as an adsorptive membrane. The composite Ch/Si/P membrane was prepared by mixing a chitosan-based membrane with silica isolated from rice husk ash (ASP) and polyethylene glycol (PEG) as a plasticizer. The resultant composite membrane was a stronger and more flexible membrane than the original chitosan-based membrane as indicated by the maximum percentage of elongation (20.5 %) and minimum Young’s Modulus (80.5 MPa). The composite membrane also showed increased mechanical and hydrophilic properties compared to the chitosan membranes. The membrane was used as adsorption membrane for Pb (II), Cu (II), Cd (II) ions and Rhodamine B dyes in a dynamic system where the permeation and selectivity were determined. The permeation of the components was observed to be in the following order: Rhodamine B > Cd (II) > Pb (II) > Cu (II) whereas the selectivity was shown to decrease the order of Cu (II) > Pb (II) > Cd (II) > Rhodamine B.

Evaluating Weathering of Food Packaging Polyethylene-Nano-clay Composites: Release of Nanoparticles and their Impacts.

Science.gov (United States)

Han, Changseok; Zhao, Amy; Varughese, Eunice; Sahle-Demessie, E

2018-01-01

Nano-fillers are increasingly incorporated into polymeric materials to improve the mechanical, barrier or other matrix properties of nanocomposites used for consumer and industrial applications. However, over the life cycle, these nanocomposites could degrade due to exposure to environmental conditions, resulting in the release of embedded nanomaterials from the polymer matrix into the environment. This paper presents a rigorous study on the degradation and the release of nanomaterials from food packaging composites. Films of nano-clay-loaded low-density polyethylene (LDPE) composite for food packaging applications were prepared with the spherilene technology and exposed to accelerated weathering of ultraviolet (UV) irradiation or low concentration of ozone at 40 °C. The changes in the structural, surface morphology, chemical and physical properties of the films during accelerated weathering were investigated. Qualitative and quantitative changes in properties of pristine and aged materials and the release of nano-clay proceeded slowly until 130 hr irradiation and then accelerated afterward resulting complete degradation. Although nano-clay increased the stability of LDPE and improved thermal and barrier properties, they accelerated the UV oxidation of LDPE. With increasing exposure to UV, the surface roughness, chemiluminescence index, and carbonyl index of the samples increased while decreasing the intensity of the wide-angle X-ray diffraction pattern. Nano-clay particles with sizes ranging from 2-8 nm were released from UV and ozone weathered composite. The concentrations of released nanoparticles increased with an increase in aging time. Various toxicity tests, including reactive oxygen species generation and cell activity/viability were also performed on the released nano-clay and clay polymer. The released nano-clays basically did not show toxicity. Our combined results demonstrated the degradation properties of nano-clay particle-embedded LDPE composites

PORTSMOUTH ON-SITE DISPOSAL CELL HIGH DENSITY POLYETHYLENE GEOMEMBRANE LONGEVITY

Energy Technology Data Exchange (ETDEWEB)

Phifer, M.

2012-01-31

It is anticipated that high density polyethylene (HDPE) geomembranes will be utilized within the liner and closure cap of the proposed On-Site Disposal Cell (OSDC) at the Portsmouth Gaseous Diffusion Plant. The likely longevity (i.e. service life) of HDPE geomembranes in OSDC service is evaluated within the following sections of this report: (1) Section 2.0 provides an overview of HDPE geomembranes, (2) Section 3.0 outlines potential HDPE geomembranes degradation mechanisms, (3) Section 4.0 evaluates the applicability of HDPE geomembrane degradation mechanisms to the Portsmouth OSDC, (4) Section 5.0 provides a discussion of the current state of knowledge relative to the longevity (service life) of HDPE geomembranes, including the relation of this knowledge to the Portsmouth OSDC, and (5) Section 6.0 provides summary and conclusions relative to the anticipated service life of HDPE geomembranes in OSDC service. Based upon this evaluation it is anticipated that the service life of HDPE geomembranes in OSDC service would be significantly greater than the 200 year service life assumed for the OSDC closure cap and liner HDPE geomembranes. That is, a 200 year OSDC HDPE geomembrane service life is considered a conservative assumption.

Portsmouth On-Site Disposal Cell High Density Polyethylene Geomembrane Longevity

International Nuclear Information System (INIS)

Phifer, M.

2012-01-01

It is anticipated that high density polyethylene (HDPE) geomembranes will be utilized within the liner and closure cap of the proposed On-Site Disposal Cell (OSDC) at the Portsmouth Gaseous Diffusion Plant. The likely longevity (i.e. service life) of HDPE geomembranes in OSDC service is evaluated within the following sections of this report: (1) Section 2.0 provides an overview of HDPE geomembranes, (2) Section 3.0 outlines potential HDPE geomembranes degradation mechanisms, (3) Section 4.0 evaluates the applicability of HDPE geomembrane degradation mechanisms to the Portsmouth OSDC, (4) Section 5.0 provides a discussion of the current state of knowledge relative to the longevity (service life) of HDPE geomembranes, including the relation of this knowledge to the Portsmouth OSDC, and (5) Section 6.0 provides summary and conclusions relative to the anticipated service life of HDPE geomembranes in OSDC service. Based upon this evaluation it is anticipated that the service life of HDPE geomembranes in OSDC service would be significantly greater than the 200 year service life assumed for the OSDC closure cap and liner HDPE geomembranes. That is, a 200 year OSDC HDPE geomembrane service life is considered a conservative assumption.

Radiation-assisted grafting of vinylidene chloride onto high-density polyethylene

Science.gov (United States)

Nagesh, N.; Dokhale, P. A.; Bhoraskar, V. N.

1999-06-01

6 MeV electrons and Co-60 icons/Journals/Common/gamma" ALT="gamma" ALIGN="TOP"/>-rays were used for grafting vinylidene chloride (VDC) onto high-density polyethylene (HDPE) samples. The HDPE samples were immersed in vinylidene chloride and irradiated either with Co-60 icons/Journals/Common/gamma" ALT="gamma" ALIGN="TOP"/>-rays or with 6 MeV electrons. In both cases, the radiation dose was varied in the range 1.25-7.5 kGy. The grafted samples were characterized by IR spectroscopy to obtain information about the chemical bonds and with the 14 MeV neutron activation analysis technique for estimating the number of chlorine atoms. The formation of stable bonds between the VDC molecules and the polymer chains could be achieved either with 6 MeV electrons or with Co-60 icons/Journals/Common/gamma" ALT="gamma" ALIGN="TOP"/>-rays. Both the number of chlorine atoms and the sample-surface conductivity increased with the radiation dose but the increases achieved with 6 MeV electrons were greater than those achieved with Co-60 icons/Journals/Common/gamma" ALT="gamma" ALIGN="TOP"/>-rays.

Morphology Development and Mechanical Properties Variation during Cold-Drawing of Polyethylene-Clay Nanocomposite Fibers

OpenAIRE

Bartolomeo Coppola; Paola Scarfato; Loredana Incarnato; Luciano Di Maio

2017-01-01

In this work, the influence of composition and cold-drawing on nano- and micro-scale morphology and tensile mechanical properties of PE/organoclay nanocomposite fibers was investigated. Nanocomposites were prepared by melt compounding in a twin-screw extruder, using a maleic anhydride grafted linear low density polyethylene (LLDPE–g–MA) and an organomodified montmorillonite (Dellite 67G) at three different loadings (3, 5 and 10 wt %). Fibers were produced by a single-screw extruder and drawn ...

Experimental study of the density and viscosity of polyethylene glycols and their mixtures at temperatures from 293 K to 473 K and at atmospheric pressure

International Nuclear Information System (INIS)

Sagdeev, D.I.; Fomina, M.G.; Mukhamedzyanov, G.Kh.; Abdulagatov, I.M.

2011-01-01

Highlights: → Viscosity and density of polyethylene glycols. → Combined experimental apparatus for density and viscosity measurements. → Vogel-Tamman-Fulcher model for viscosity. - Abstract: A new apparatus to measure simultaneously the density and viscosity of liquids has been designed and constructed based on the hydrostatic weighing and falling-body principles. The density and viscosity of monoethylene glycol (MEG), diethylene glycol (DEG), and triethylene glycol (TEG) and their binary, (50%MEG + 50%DEG), (50%MEG + 50%TEG), (50%DEG + 50%TEG), and ternary (33.33%MEG + 33.33%DEG + 33.34%TEG) mixtures have been measured over the temperature range from 293 K to 473 K and at atmospheric pressure. The expanded uncertainty of the density, pressure, temperature, and viscosity measurements at the 95% confidence level with a coverage factor of k = 2 is estimated to be 0.15% to 0.30%, 0.05%, 0.06 K, and 1.5% to 2.0% (depending on temperature and pressure ranges), respectively. The theoretically based Arrhenius-Andrade and Vogel-Tamman-Fulcher type equations were used to describe the temperature dependence of measured viscosities for pure polyethylene glycols and their mixtures.

Effect of processing method on the mechanical and thermal of Silvergrass/HDPE composites

Science.gov (United States)

Liu, Bing; Jin, Yueqiang; Wang, Shuying

2017-05-01

This paper investigates the effect of compression and injection molding methods on properties of Silvergrass-HDPE (High Density Polyethylene) composites, with respect to mechanical behaviors. Maleated polyethylene (MAPE) was added in the composite and improved the mechanical property of the composite. The research founds MAPE can improve the mechanical property because it improved the interfacial compatibility as a coupling agent. When added a content of 8% of MAPE, Silvergrass-HDPE composites made from compression molding shows a better mechanical performance in tensile strength and flexural strength than that made from injection molding, with increasing Silvergrass fiber content from 30% to 50%. However, the WPCs (wood plastics composites) made from injection molding had a lower degree of crystallinity with or without MAPE treatment.

Study of the effect of gamma irradiation on carbon black loaded low-density polyethylene films

International Nuclear Information System (INIS)

Salem, M.A.; Hussein, A.; El-Ahdal, M.A.

2003-01-01

The effect of gamma irradiation on the tensile and physico-chemical properties of low-density polyethylene (LDPE) films loaded with different concentrations of carbon black (C.B) has been studied. The results showed that the behavior of the samples during gamma irradiation is complicated and this may be due to scission and the interaction between oxidation and crosslinking processes. The tensile properties are modified by the presence of carbon black. Film sample containing 7% C.B was found to exhibit a nearly stabilized tensile behavior with radiation dose, which allows to use this formulation in packaging for food sterilization and in preservation of weak cobalt-gamma sources. (author)

Temperature dependence study of positronium formation in high density polyethylene by positron annihilation lifetime spectroscopy

International Nuclear Information System (INIS)

Nahid, F.; Beling, C.D.; Fung, S.

2007-01-01

Positron annihilation lifetime spectroscopy has been used to study the formation of positronium in high density polyethylene as a function of temperature over the range 30 K-350 K. It is observed that the thermal history of the sample, while having no influence on the positronium lifetime, has a strong effect on the formation of positronium. A hysteresis is seen in the positronium formation probability in cooling and heating cycles. This is explained on a two channel formation model, the first channel being through ''blob'' formation and the second through the pick-up of shallow trapped electrons. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Strength and thermal stability of fiber reinforced plastic composites ...

African Journals Online (AJOL)

Therefore, the strength properties and thermal stability of plastic composites reinforced with rattan fibers were investigated in this work. Particles of rattan species (Eremospatha macrocarpa (EM) and Laccosperma secundiflorum (LS)) were blended with High-Density Polyethylene (HDPE) to produce fiber reinforced plastic ...

Pengaruh Konsentrasi Maleat Anhidrat Terhadap Derajat Grafting Maleat Anhidrat Pada High Density Polyethylene ( HDPE ) Dengan Inisiator Benzoil Peroksida

OpenAIRE

Iwan Pranata Sitepu

2009-01-01

Telah dilakukan penelitian tentang pengaruh konsentrasi maleat anhidrat terhadap derajat grafting maleat anhidrat pada High Density Polyethylene ( HDPE ) dengan inisiator Benzoil Peroksida, dilakukan dengan teknik pengolahan reaktif dalam Internal Mixer pada suhu 1450C dan waktu proses selama 60 menit dengan variasi komposisi HDPE:MA:BPO, 95:3:2, 92:6:2, 89:9:2, 86:12:2 dan 83:15:2. Selanjutnya dilakukan penentuan derajat grafting dengan metode titrasi dan analisis spektra FTIR untuk menen...

Chemical recycling of plastic wastes made from polyethylene (LDPE and HDPE) and polypropylene (PP)

International Nuclear Information System (INIS)

Achilias, D.S.; Roupakias, C.; Megalokonomos, P.; Lappas, A.A.; Antonakou, E.V.

2007-01-01

The recycling of either model polymers or waste products based on low-density polyethylene (LDPE), high-density polyethylene (HDPE) or polypropylene (PP) is examined using the dissolution/reprecipitation method, as well as pyrolysis. In the first technique, different solvents/non-solvents were examined at different weight percent amounts and temperatures using as raw material both model polymers and commercial products (packaging film, bags, pipes, food-retail outlets). The recovery of polymer in every case was greater than 90%. FT-IR spectra and tensile mechanical properties of the samples before and after recycling were measured. Furthermore, catalytic pyrolysis was carried out in a laboratory fixed bed reactor with an FCC catalyst using again model polymers and waste products as raw materials. Analysis of the derived gases and oils showed that pyrolysis gave a mainly aliphatic composition consisting of a series of hydrocarbons (alkanes and alkenes), with a great potential to be recycled back into the petrochemical industry as a feedstock for the production of new plastics or refined fuels

Chemical recycling of plastic wastes made from polyethylene (LDPE and HDPE) and polypropylene (PP).

Science.gov (United States)

Achilias, D S; Roupakias, C; Megalokonomos, P; Lappas, A A; Antonakou, Epsilon V

2007-11-19

The recycling of either model polymers or waste products based on low-density polyethylene (LDPE), high-density polyethylene (HDPE) or polypropylene (PP) is examined using the dissolution/reprecipitation method, as well as pyrolysis. In the first technique, different solvents/non-solvents were examined at different weight percent amounts and temperatures using as raw material both model polymers and commercial products (packaging film, bags, pipes, food-retail outlets). The recovery of polymer in every case was greater than 90%. FT-IR spectra and tensile mechanical properties of the samples before and after recycling were measured. Furthermore, catalytic pyrolysis was carried out in a laboratory fixed bed reactor with an FCC catalyst using again model polymers and waste products as raw materials. Analysis of the derived gases and oils showed that pyrolysis gave a mainly aliphatic composition consisting of a series of hydrocarbons (alkanes and alkenes), with a great potential to be recycled back into the petrochemical industry as a feedstock for the production of new plastics or refined fuels.

Atomistic simulation of CO 2 solubility in poly(ethylene oxide) oligomers

KAUST Repository

Hong, Bingbing; Panagiotopoulos, Athanassios Z.

2013-01-01

We have performed atomistic molecular dynamics simulations coupled with thermodynamic integration to obtain the excess chemical potential and pressure-composition phase diagrams for CO2 in poly(ethylene oxide) oligomers. Poly(ethylene oxide

Salt-Induced Control of the Grafting Density in Poly(ethylene glycol) Brush Layers by a Grafting-to Approach

DEFF Research Database (Denmark)

Ortiz, Roberto; Olsen, Stefan; Thormann, Esben

2018-01-01

In this work, a method to obtain control of the grafting density during the formation of polymer brush layers by the grafting-to method of thiolated poly(ethylene glycol) onto gold is presented. The grafting density of the polymer chains was adjusted by adding Na2SO4 in concentrations between 0.......2 and 0.9 M to the aqueous polymer solution during the grafting process. The obtained grafting densities ranged from 0.26 to 1.60 chains nm-2, as determined by surface plasmon resonance. The kinetics of the grafting process were studied in situ by a quartz crystal microbalance with dissipation......, and a mushroom to brush conformational transition was observed when the polymer was grafted in the presence of Na2SO4. The transition from mushroom to brush was only observed for long periods of grafting, highlighting the importance of time to obtain high grafting densities. Finally, the prepared brush layer...

Molecular weight​/branching distribution modeling of low-​density-​polyethylene accounting for topological scission and combination termination in continuous stirred tank reactor

NARCIS (Netherlands)

Yaghini, N.; Iedema, P.D.

2014-01-01

We present a comprehensive model to predict the molecular weight distribution (MWD),(1) and branching distribution of low-density polyethylene (IdPE),(2) for free radical polymerization system in a continuous stirred tank reactor (CSTR).(3) The model accounts for branching, by branching moment or

Tensile behaviour and properties of a bone analogue composite (HA, HDPE) crosslinked by gamma radiation

International Nuclear Information System (INIS)

Romero, G.; Smolko, Eduardo E.

2005-01-01

A natural composite material, hydroxyapatite (HA) and high density polyethylene (HDPE) crosslinked by ionizing radiations is been developed as a bioactive analogue material for bone replacement. Mechanical properties of the composites irradiated up to 300 kGy under tensile tests was studied. Gel content and micrographs of different composite fractures are shown. (author)

Caracterisation des proprietes dielectriques de materiaux composites a base de polyethylene terephtalate recycle

Science.gov (United States)

Mebarki, Fouzia

The aim of this study is to examine the possibility of using thermoplastic composite materials for electrical applications such as supports of automotive engine ignition systems. We are particularly interested in composites based on recycled polyethylene terephtalate (PET). Conventional isolations like PET cannot meet the new prescriptive requirements. The introduction of reinforcement materials, such as glass fibers and mica can improve the mechanical characteristics of these materials. However, this enhancement may also reduce electrical properties especially since these composites have to be used under severe thermal and electric stresses. In order to estimate PET composite insulation lifetimes, accelerated aging tests were carried out at temperatures ranging from room temperature to 140°C and at a frequency of 300Hz. Studies at high temperature will help to identify the service temperature of candidate materials. Dielectric breakdown tests have been made on a large number of samples according to the standard of dielectric strength tests of solid insulating ASTM D-149. These tests have to identify the problematic samples and to check solid insulation quality. The different knowledge gained from this analysis was used to predict material performance. This will give the company the possibility to improve existing formulations and subsequently develop a material having electrical and thermal properties suitable for this application.

Mechanical Property Characteristics of Butt-Fusion Joint of High Density Polyethylene Pipe for NPP Safety Class Application

International Nuclear Information System (INIS)

Oh, Youngjin; Kim, Kyoungsu; Lee, Seunggun; Park, Heungbae; Yu, Jeongho; Kim, Jongsung; Kim, Jeonghyun; Jang, Changheui; Choi, Sunwoong

2013-01-01

Several NPPs in United States replaced parts of sea water or raw water system pipes to HDPE (high density polyethylene) pipes, which have outstanding resistance for oxidation and seismic loading. ASME B and PV code committee developed Code Case N-755, which describes rules for the construction of Safety Class 3 polyethylene pressure piping components. Several NPP's in US proposed relief requests in order to apply Code Case N-755. Although US NRC permitted using Code Case N-755 and HDPE materials for Class 3 buried piping, their permission was limited to only 10 years because of several concerns for material performance of HDPE. US NRC's major concerns are about material properties and the quality of fusion zone of HDPE. In this study, material property tests for HDPE fusion zone are conducted with varying standard fusion procedures. Mechanical property tests for fused material for HDPE pipes were conducted. Fused material shows lower toughness than base material and fused material of lower fusion pressure shows higher toughness than that of higher fusion pressure

Biodegradation of low density polyethylene (LDPE) by a new ...

African Journals Online (AJOL)

aghomotsegin

The microbial degradation of LDPE was also analyzed by the change in pH of the culture ... The generation of biodegradable polyethylene requires ...... Use of scanning electron microscope for the examination of actinomycetes. J. Gen. Microbiol. 48:171-177. Yamada-Onodera K, Mukumoto H, Katsuyaya Y, Saiganji A, Tani ...

Pyrolysis of olive residue/low density polyethylene mixture:Part I Thermogravimetric kinetics

Institute of Scientific and Technical Information of China (English)

无

2008-01-01

This paper demonstrates the thermal pyrolysis of olive residue, low density polyethylene (LDPE) and olive residue/LDPE mixture in an inert atmosphere of N2 using thermogravimetric analysis (TGA). Measurements were carried out in the temperature range 300K~973K at heating rates of 2K/min, 10K/min, 20K/min and 50K/min. Based on the results obtained, three temperature regimes were selected for studying the non-isothermal kinetics of olive residue/LDPE mixture. The first two were dominated by the olive residue pyrolysis, while the third was linked to the LDPE pyrolysis, which occurred at much higher temperatures. Discrepancies between the experimental and calculated TG/DTG profiles were considered as a measurement of the extent of interactions occurring on co-pyrolysis. The maximum degradation temperatures of each component in the mixture were higher than those the individual components;thus an increase in thermal stability was expected. The kinetic parameters associated with thermal degradation were determined using Friedman isoconversional method.

Tuning the Density of Poly(ethylene glycol Chains to Control Mammalian Cell and Bacterial Attachment

Directory of Open Access Journals (Sweden)

Ahmed Al-Ani

2017-08-01

Full Text Available Surface modification of biomaterials with polymer chains has attracted great attention because of their ability to control biointerfacial interactions such as protein adsorption, cell attachment and bacterial biofilm formation. The aim of this study was to control the immobilisation of biomolecules on silicon wafers using poly(ethylene glycol(PEG chains by a “grafting to” technique. In particular, to control the polymer chain graft density in order to capture proteins and preserve their activity in cell culture as well as find the optimal density that would totally prevent bacterial attachment. The PEG graft density was varied by changing the polymer solubility using an increasing salt concentration. The silicon substrates were initially modified with aminopropyl-triethoxysilane (APTES, where the surface density of amine groups was optimised using different concentrations. The results showed under specific conditions, the PEG density was highest with grafting under “cloud point” conditions. The modified surfaces were characterised with X-ray photoelectron spectroscopy (XPS, ellipsometry, atomic force microscopy (AFM and water contact angle measurements. In addition, all modified surfaces were tested with protein solutions and in cell (mesenchymal stem cells and MG63 osteoblast-like cells and bacterial (Pseudomonas aeruginosa attachment assays. Overall, the lowest protein adsorption was observed on the highest polymer graft density, bacterial adhesion was very low on all modified surfaces, and it can be seen that the attachment of mammalian cells gradually increased as the PEG grafting density decreased, reaching the maximum attachment at medium PEG densities. The results demonstrate that, at certain PEG surface coverages, mammalian cell attachment can be tuned with the potential to optimise their behaviour with controlled serum protein adsorption.

The use of poly(ethylene terephthalate)-poly(aniline) composite for trypsin immobilisation

Energy Technology Data Exchange (ETDEWEB)

Caramori, S.S. [Laboratorio de Quimica de Proteinas, Departamento de Bioquimica e Biologia Molecular, Instituto de Ciencias Biologicas, Universidade Federal de Goias, Cx. Postal 131, 74001-970 Goiania-GO (Brazil)], E-mail: samanthabio@hotmail.com; Fernandes, K.F. [Laboratorio de Quimica de Proteinas, Departamento de Bioquimica e Biologia Molecular, Instituto de Ciencias Biologicas, Universidade Federal de Goias, Cx. Postal 131, 74001-970 Goiania-GO (Brazil)], E-mail: katia@icb.ufg.br

2008-08-01

This paper presents trypsin immobilisation on strips of poly(ethylene terephthalate)-poly(aniline), activated with glutaraldehyde (PET-PANIG) composite. The photomicrography of the material showed changes corresponding to the chemical modifications produced in the steps of synthesis. The immobilisation process was very efficient under optimal conditions (18.6%). The immobilised and free enzyme presented the same pH and temperature optimum. PET-PANIG-trypsin was able to hydrolyse casein, albumin, gelatine, and skimmed milk. Km{sub app} value for PET-PANIG-trypsin was very close to Km of the free enzyme for casein. Immobilised trypsin showed higher stability than the free enzyme, with 100% activity after 14 days of storage at 4 deg. C and 100% operational stability after 4 cycles of use.

Safety and durability of low-density polyethylene bags in solar water disinfection applications.

Science.gov (United States)

Danwittayakul, Supamas; Songngam, Supachai; Fhulua, Tipawan; Muangkasem, Panida; Sukkasi, Sittha

2017-08-01

Solar water disinfection (SODIS) is a simple point-of-use process that uses sunlight to disinfect water for drinking. Polyethylene terephthalate (PET) bottles are typically used as water containers for SODIS, but a new SODIS container design has recently been developed with low-density polyethylene (LDPE) bags and can overcome the drawbacks of PET bottles. Two nesting layers of LDPE bags are used in the new design: the inner layer containing the water to be disinfected and the outer one creating air insulation to minimize heat loss from the water to the surroundings. This work investigated the degradation of LDPE bags used in the new design in actual SODIS conditions over a period of 12 weeks. The degradation of the LDPE bags was investigated weekly using a scanning electron microscope, Fourier transform infrared spectroscopy, ultraviolet-visible spectrophotometer, and tensile strength tester. It was found that the LDPE bags gradually degraded under the sunlight due to photo-oxidation reactions, especially in the outer bags, which were directly exposed to the sun and surroundings, leading to the reduction of light transmittance (by 11% at 300 nm) and tensile strength (by 33%). In addition, possible leaching of organic compounds into the water contained in the inner bags was examined using gas chromatography-mass spectrometer. 2,4-Di-tert-butylphenol was found in some SODIS water samples as well as the as-received water samples, in the concentration range of 1-4 μg/L, which passes the Environmental Protection Agency Drinking Water Guidance on Disinfection By-Products.

A study of gamma-irradiated polyethylenes by temperature modulated differential scanning calorimetry

Science.gov (United States)

Galovic, S.; Secerov, B.; Trifunovic, S.; Milicevic, D.; Suljovrujic, E.

2012-09-01

Various polyethylenes (PEs) and the effects of high-energy radiation on their structures were widely studied in the past using conventional Differential Scanning Calorimetry (DSC) measurements. In this work, we used the Temperature Modulated Differential Scanning Calorimetry (TMDSC) technique in order to obtain more information about the influence of the initial structural differences and gamma radiation on the evolution in structure and thermal properties of different polyethylenes. For this reason, low density polyethylene (LDPE), linear low density polyethylene (LLDPE) and high density polyethylene (HDPE) samples were exposed to gamma radiation, in air, to a wide range of absorbed doses (up to 2400 kGy). The separation of the total heat flow TMDSC signal into a reversing and non-reversing part enabled us to observe the low-temperature enthalpy relaxation (related to the existence of the "rigid amorphous phase") and recrystallisation processes, as well as to follow their radiation-induced evolution and/or that of melting in a more revealing manner compared to the case of the conventional DSC. Consequently, our results indicate that TMDSC could improve the understanding of radiation-induced effects in polymers.

Thermal properties of polyethylene reinforced with recycled–poly (ethylene terephthalate) flakes.

Science.gov (United States)

Ruqiyah Nik Hassan, Nik; Mazni Ismail, Noor; Ghazali, Suriati; Nuruzzaman, Dewan Muhammad

2018-04-01

In this study, recycled plastic bottles (RPET) were used as a filler in high density polyethylene (HDPE) thermoplastic. The plastic sheet of RPET/HDPE was prepared by using hot and cold press machine. The effects of RPET addition and hot press process to the thermal properties of the composite RPET/HDPE were investigated using differential scanning calorimetry (DSC) and thermogravimetric (TGA). Results from DSC analysis show that the melting point of HDPE slightly shifted to a higher temperature for about 2°C to 4°C with the addition of RPET as a filler. The starting degradation temperature of RPET/HDPE composite examined from TGA analysis also seen to be slightly increased. It was observed that the incorporation of recycled PET flakes into HDPE is achievable using hot press process with slight improvement seen in both melting point and thermal stability of the composite compared to the neat HDPE.

Effect of PET functionalization in composites of

Directory of Open Access Journals (Sweden)

Cristina Cazan

2017-03-01

Full Text Available The functionalization of polyethylene terephthalate (PET from tire rubber–PET–high density polyethylene (HDPE composites represents a key strategy for improving the composite properties. This is a practical and effective method to improve the interface between matrix (waste tire rubber and fillers (waste PET and HDPE. By PET functionalization, adherence and surface properties of composite materials can be controlled. PET functionalization was performed with polyethylene glycol (PEG 400, 1% and sodium dodecyl sulphate (SDS 1%. The characterization of the components and composite are discussed in terms of surface energy values (evaluated from water contact angle measurements and surface morphology by using scanning electron microscopy (SEM. The structural and conformational changes were investigated by Fourier Transform Infrared (FTIR Spectroscopy while the crystalline structure was studied by X-ray diffraction (XRD. The improved interfacial adhesion, thermal stability and mechanical properties (stress–strain, compression and impact resistance of the composites are correlated with the PET functionalization, with non-ionic (PEG and an anionic surfactant (SDS. The results proved that the interface properties are improved by functionalization of PET. The best mechanical properties were recorded at 30 min moulding. The samples with 45% PET–SDS showed the best combination of mechanical properties: tensile strength (1.56 N/mm2, impact strength (43.72 kJ/m2 and compression (158.78 N/mm2.

Anisotropic dynamic mass density for fluidsolid composites

KAUST Repository

Wu, Ying; Mei, Jun; Sheng, Ping

2012-01-01

By taking the low frequency limit of multiple-scattering theory, we obtain the dynamic effective mass density of fluidsolid composites with a two-dimensional rectangular lattice structure. The anisotropic mass density can be described by an angle

Suitability of Recycled Polyethylene/Palm Kernel Shell-Iron Filings Composite for Automobile Application

Directory of Open Access Journals (Sweden)

I.A. Samotu

2015-06-01

Full Text Available A recycling aimed research was carried out to produce a new composite material and proffer suggestion for the possible use of the newly developed composite material. The empty water sachet (commonly called pure water nylon in Nigeria, was used as a matrix, which was reinforced by carbonized palm kernel shell (CPKS particulate and iron fillings. The percentage composition of iron fillings was maintained at 5 wt%, while that of palm kernel shell ash was varied from 5 wt% - 20 wt% at an interval of 5 %. The composites were compounded and compressively moulded. Physical and mechanical properties of the composites were tested for alongside three conventional car bumper samples, and the results obtained shows that the composite material could be used to produce a car bumper among other parts of automobile like dashboard due to their impact strength and low density. Impact strength - density ratio for the materials gave prime information on the possible application of the developed material. Scanning Electron Microscope (SEM was used to examine the distribution of the reinforcement within the matrix. After results analysis, materials with 5 wt% of CPKS and that with 10 wt% of CPKS were recommended for the car bumper production following their high impact strength - density ratio of 0.26 and 0.19 respectively, which are higher as compared to that of a conventional bumper material measured alongside the composite materials.

Ultralow energy ion beam surface modification of low density polyethylene.

Science.gov (United States)

Shenton, Martyn J; Bradley, James W; van den Berg, Jaap A; Armour, David G; Stevens, Gary C

2005-12-01

Ultralow energy Ar+ and O+ ion beam irradiation of low density polyethylene has been carried out under controlled dose and monoenergetic conditions. XPS of Ar+-treated surfaces exposed to ambient atmosphere show that the bombardment of 50 eV Ar+ ions at a total dose of 10(16) cm(-2) gives rise to very reactive surfaces with oxygen incorporation at about 50% of the species present in the upper surface layer. Using pure O+ beam irradiation, comparatively low O incorporation is achieved without exposure to atmosphere (approximately 13% O in the upper surface). However, if the surface is activated by Ar+ pretreatment, then large oxygen contents can be achieved under subsequent O+ irradiation (up to 48% O). The results show that for very low energy (20 eV) oxygen ions there is a dose threshold of about 5 x 10(15) cm(-2) before surface oxygen incorporation is observed. It appears that, for both Ar+ and O+ ions in this regime, the degree of surface modification is only very weakly dependent on the ion energy. The results suggest that in the nonequilibrium plasma treatment of polymers, where the ion flux is typically 10(18) m(-2) s(-1), low energy ions (<50 eV) may be responsible for surface chemical modification.

Effects of processing method and moisture history on laboratory fungal resistance of wood-HDPE composites.

Science.gov (United States)

Craig M. Clemons; Rebecca E. Ibach

2004-01-01

The purpose of this study was to clarify the effects of composite processing and moisture sorption on laboratory fungal resistance of wood-plastic composites. A 2-week water soaking or cyclic boiling-drying procedure was used to infuse moisture into composites made from high-density polyethylene filled with 50 percent wood flour and processed by extrusion, compression...

Experimental study of co-pyrolysis of polyethylene/sawdust mixtures

Directory of Open Access Journals (Sweden)

Berrueco Cesar

2004-01-01

Full Text Available A study of the behavior of the thermal decomposition of mixtures of biomass and thermoplastics, such as polyethylene, is of interest for processes for the thermal recovery of industrial and urban wastes such as pyrolysis or gasification. No solid residue is formed during the thermal degradation of pure polyethylene. However, the addition of biomass, which generates char can vary the product distribution and increase the heating value of the gas obtained. A study of the thermal degradation of pine sawdust, polyethylene and mixtures of polyethylene and pine sawdust has been carried out in a fluidized bed reactor. Experiments were carried out at five different temperatures: 640, 685, 730, 780, and 850 ºC. The yields and composition of the derived oil, wax, and gas were determined. The addition of polyethylene increases the gas production and decreases the production of waxes and liquids for the different temperatures tested. The main gases produced from the co-pyrolysis process were, at low temperatures, carbon monoxide ethylene, carbon dioxide, propylene, butadiene, methane and pentadiene while at high temperatures the gas composition changed drastically, the main components being carbon monoxide (more than 33 wt.%, ethylene, methane benzene and hydrogen. The analysis of the liquid fraction shows a decrease of the concentration of oxygenated and aliphatic compounds.

Effect of ionizing radiation on nanocomposites of high density polyethylene with pseudoboehmite obtained by sol-gel process

International Nuclear Information System (INIS)

Miranda, Leila F.; Munhoz Junior, Antonio H.; Terence, Mauro C.; Alves, Alexandre P.

2009-01-01

Nanocomposites are polymeric hybrid materials where inorganic substances of nanometric dimensions are dispersed in a polymeric matrix. The fillers present area of raised surface, promoting better dispersion in the polymeric matrix and therefore an improvement of the physical properties of the composite that depends on the homogeneity of the material. The nanocomposites preparation with polymeric matrix allows in many cases to find a relation enters a low cost, due to the use of minor amount of filler, and a raised performance level. Nanocomposites were obtained with pseudoboehmite synthesized by sol-gel process and high density polyethylene with different concentrations of pseudoboehmite. The aim of this work was to study the effects of ionizing radiation on the properties of the nanocomposites obtained. The nanocomposites were prepared by melt intercalation technique and subsequently, the samples were molded by injection, irradiated and submitted to thermal and mechanical tests. The mechanical properties (impact strength and tensile strength), temperature of thermal distortion (HDT) and Vicat softening temperature of the non irradiated and irradiated nanocomposites were determined. The irradiation doses were of 30, 50 and 100kGy in a gamma cell. The results showed an increase in the values of tensile strength; a decrease in the impact strength and an increase in the temperature of thermal distortion (HDT) evidencing the interaction of nanofiller with the polymeric matrix. (author)

The relationship between sol fraction and radiation dose in radiation crosslinking of low-density polyethylene (LDPE)/ethylenevinylacetate copolymer (EVA) blend

International Nuclear Information System (INIS)

Zhang, W.X.; Liu, Y.T.; Sun, J.Z.

1990-01-01

In this paper, two different methods were used to prepare the blend of low-density polyethylene (LDPE) and ethylene vinyl acetate copolymer (EVA). One of them was mechanical blending, and the other was solution blending. The relationship between sol fraction and radiation dose of different weight ratio polymer blends has been studied. The method to calculate the β b value of polymer blend system (LDPE/EVA) has been established. (author)

Influence of adipic acid on tensile and morphology properties of linear low density polyethylene/rambutan peels flour blends

Science.gov (United States)

Nadhirah, A. A.; Sam, S. T.; Noriman, N. Z.; Ragunathan, S.; Ismail, H.

2015-07-01

This study investigate about the tensile and morphological properties of degradable polymer produced from linear low density polyethylene/rambutan peel flour (LLDPE/RPF) blends and adipic acid (AA) was used as a compatibilizer by varying the rambutan peel flour (RPF) amount from 0-25wt%. The samples were subjected to tensile and morphological tests. AA compatibilized showed higher strength compared to uncompatibilized blends. The Young's modulus for LLDPE/RPF blends increased with increasing flour content. However, the addition of adipic acid had reduced the Young's Modulus.

The effect of gamma radiation on hardness evolution in high density polyethylene at elevated temperatures

International Nuclear Information System (INIS)

Chen, Pei-Yun; Chen, C.C.; Harmon, Julie P.; Lee, Sanboh

2014-01-01

This research focuses on characterizing hardness evolution in irradiated high density polyethylene (HDPE) at elevated temperatures. Hardness increases with increasing gamma ray dose, annealing temperature and annealing time. The hardness change is attributed to the variation of defects in microstructure and molecular structure. The kinetics of defects that control the hardness are assumed to follow the first order structure relaxation. The experimental data are in good agreement with the predicted model. The rate constant follows the Arrhenius equation, and the corresponding activation energy decreases with increasing dose. The defects that control hardness in post-annealed HDPE increase with increasing dose and annealing temperature. The structure relaxation of HDPE has a lower energy of mixing in crystalline regions than in amorphous regions. Further, the energy of mixing for defects that influence hardness in HDPE is lower than those observed in polycarbonate (PC), poly(methyl methacrylate) (PMMA) and poly (hydroxyethyl methacrylate) (HEMA). This is due to the fact that polyethylene is a semi-crystalline material, while PC, PMMA and PHEMA are amorphous. - Highlights: • Hardness of HDPE increases with increasing gamma ray dose, annealing time and temperature. • The hardness change arises from defects in microstructure and molecular structure. • Defects affecting hardness follow a kinetics of structure relaxation. • The structure relaxation has a low energy of mixing in crystalline regime

The effect of gamma radiation on hardness evolution in high density polyethylene at elevated temperatures

Energy Technology Data Exchange (ETDEWEB)

Chen, Pei-Yun [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 300, Taiwan (China); Chen, C.C. [Institute of Nuclear Energy Research, Longtan, Taoyuan 325, Taiwan (China); Harmon, Julie P. [Department of Chemistry, University of South Florida, Tampa, FL 33620 (United States); Lee, Sanboh, E-mail: sblee@mx.nthu.edu.tw [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 300, Taiwan (China)

2014-08-01

This research focuses on characterizing hardness evolution in irradiated high density polyethylene (HDPE) at elevated temperatures. Hardness increases with increasing gamma ray dose, annealing temperature and annealing time. The hardness change is attributed to the variation of defects in microstructure and molecular structure. The kinetics of defects that control the hardness are assumed to follow the first order structure relaxation. The experimental data are in good agreement with the predicted model. The rate constant follows the Arrhenius equation, and the corresponding activation energy decreases with increasing dose. The defects that control hardness in post-annealed HDPE increase with increasing dose and annealing temperature. The structure relaxation of HDPE has a lower energy of mixing in crystalline regions than in amorphous regions. Further, the energy of mixing for defects that influence hardness in HDPE is lower than those observed in polycarbonate (PC), poly(methyl methacrylate) (PMMA) and poly (hydroxyethyl methacrylate) (HEMA). This is due to the fact that polyethylene is a semi-crystalline material, while PC, PMMA and PHEMA are amorphous. - Highlights: • Hardness of HDPE increases with increasing gamma ray dose, annealing time and temperature. • The hardness change arises from defects in microstructure and molecular structure. • Defects affecting hardness follow a kinetics of structure relaxation. • The structure relaxation has a low energy of mixing in crystalline regime.

Matter composition at high density by effective scaled lagrangian

Energy Technology Data Exchange (ETDEWEB)

Hyun, Chang Ho; Min, Dong Pil [Dept. of Physics, Seoul National Univ., Seoul (Korea, Republic of)

1998-06-01

We investigate the matter composition at around the neutron star densities with a model lagrangian satisfying Brown-Rho scaling law. We calculate the neutron star properties such as maximum mass, radius, hyperon compositions and central density. We compare our results with those of Walecka model. (orig.)

Thermal stability of radiation-modified polyethylene

International Nuclear Information System (INIS)

Vinogradova, T.B.; Sirota, A.G.; Bal'tenas, R.A.; Stanyavichus, V.I.; Knebel'man, A.M.; Sil'chenko, S.A.

1989-01-01

In the work reported here, the authors investigated the thermooxidative resistance, at temperatures from 373 to 473 K, of polyethylene that had been cross-linked by exposure to radiation and formulated with various heat stabilizers. Thus, these studies of the thermooxidative resistance of polyethylene-based compositions that have been cross-linked by the radiation-chemical method have shown that, in this particular series of heat-stabilizers, the greatest effect at temperatures of 373-473 K is given by the FAU-13. The DTPhDMI has the greatest heat-stabilizing effect in the temperature interval 448-473 K, whereas the heat resistance of materials containing Diaphen NN or Phenozan-23 is higher at 373-423 K. These comparative results are in agreement with data for unirradiated and chemically cross-linked polyethylene

Quantification of branching in model three-arm star polyethylene

KAUST Repository

Ramachandran, Ramnath; Beaucage, Gregory B.; Rai, Durgesh K.; Lohse, David J.; Sun, Thomas; Tsou, Andy; Norman, Alexander Iain; Hadjichristidis, Nikolaos

2012-01-01

The versatility of a novel scaling approach in quantifying the structure of model well-defined 3-arm star polyethylene molecules is presented. Many commercial polyethylenes have long side branches, and the nature and quantity of these branches varies widely among the various forms. For instance, low-density polyethylene (LDPE) is typically a highly branched structure with broad distributions in branch content, branch lengths and branch generation (in hyperbranched structures). This makes it difficult to accurately quantify the structure and the inherent structure-property relationships. To overcome this drawback, model well-defined hydrogenated polybutadiene (HPB) structures have been synthesized via anionic polymerization and hydrogenation to serve as model analogues to long-chain branched polyethylene. In this article, model 3-arm star polyethylene molecules are quantified using the scaling approach. Along with the long-chain branch content in polyethylene, the approach also provides unique measurements of long-chain branch length and hyperbranch content. Such detailed description facilitates better understanding of the effect of branching on the physical properties of polyethylene. © 2012 American Chemical Society.

Quantification of branching in model three-arm star polyethylene

KAUST Repository

Ramachandran, Ramnath

2012-01-24

The versatility of a novel scaling approach in quantifying the structure of model well-defined 3-arm star polyethylene molecules is presented. Many commercial polyethylenes have long side branches, and the nature and quantity of these branches varies widely among the various forms. For instance, low-density polyethylene (LDPE) is typically a highly branched structure with broad distributions in branch content, branch lengths and branch generation (in hyperbranched structures). This makes it difficult to accurately quantify the structure and the inherent structure-property relationships. To overcome this drawback, model well-defined hydrogenated polybutadiene (HPB) structures have been synthesized via anionic polymerization and hydrogenation to serve as model analogues to long-chain branched polyethylene. In this article, model 3-arm star polyethylene molecules are quantified using the scaling approach. Along with the long-chain branch content in polyethylene, the approach also provides unique measurements of long-chain branch length and hyperbranch content. Such detailed description facilitates better understanding of the effect of branching on the physical properties of polyethylene. © 2012 American Chemical Society.

Heat shrinkable behavior, physico-mechanical and structure properties of electron beam cross-linked blends of high-density polyethylene with acrylonitrile-butadiene rubber

International Nuclear Information System (INIS)

Reinholds, Ingars; Kalkis, Valdis; Merijs-Meri, Remo; Zicans, Janis; Grigalovica, Agnese

2016-01-01

In this study, heat-shrinkable composites of electron beam irradiated high-density polyethylene (HDPE) composites with acrylonitrile-butadiene rubber (NBR) were investigated. HDPE/NBR blends at a ratio of components 100/0, 90/10, 80/20, 50/50 and 20/80 wt% were prepared using a two-roll mill. The compression molded films were irradiated high-energy (5 MeV) accelerated electrons up to irradiation absorbed doses of 100–300 kGy. The effect of electron beam induced cross-linking was evaluated by the changes of mechanical properties, gel content and by the differences of thermal properties, detected by differential scanning calorimetry. The thermo-shrinkage forces were determined as the kinetics of thermorelaxation and the residual shrinkage stresses of previously oriented (stretched up to 100% at above melting temperature of HDPE and followed by cooling to room temperature) specimens of irradiated HDPE/NBR blends under isometric heating–cooling mode. The compatibility between the both components was enhanced due to the formation of cross-linked sites at amorphous interphase. The results showed increase of mechanical stiffness of composites with increase of irradiation dose. The values of gel fraction compared to thermorelaxation stresses increased with the growth of irradiation dose level, as a result of formation cross-linked sites in amorphous PP/NBR interphase. - Highlights: • Binary blends of HDPE/NBR have been irradiated with 5 MeV accelerated electrons. • Increase of NBR content and irradiation dose improves cross-linking efficiency. • Thermo-shrinkage and residual stresses are investigated for oriented specimens. • Cross-linked HDPE/NBR composites can be successfully used as thermos-shrinkable materials.

Changes in wood flour/HDPE composites after accelerated weathering with and without water spray

Science.gov (United States)

Nicole M. Stark

2005-01-01

Wood-plastic lumber is promoted as a low-maintenance high-durability product. After weathering, however, wood-plasticcomposites (WPCs) often fide and lose mechanical properties. In the first part ofthis study, 50%wood-flour-filled high-density polyethylene (HDPE) composite samples were injection molded or extruded. Composites were exposed to two accelerated weathering...

Effect of Radiation on Physical and Mechanical Properties of Polyblend polyethylene (LDPE)-Akrilonitril Butadiene Styrene(ADS)

International Nuclear Information System (INIS)

Infrawan, M.H.; Mashuri; Sudirman

2001-01-01

Poly blend material is blended material that made of two or more polymer material with or without chemical reaction. Polyethylene (LDPE)- ABS poly blend material was made of two materials, ABS resin and Low Density Polyethylene (LDPE). This research is conducted to synthesize LDPE and ABS poly blend material before and after irradiation by γ ray and to investigate the effect of γ-ray irradiation doses on mechanical, and physical properties. This effect will enhanced mechanical properties of poly blend LDPE and ABS material that was caused by crosslinking. The gel fraction showed that the crosslinking occurred. The other effect of γ-ray irradiation are increased tensile strength and melting point, but the elongation at break, and yield strength decreased. The best composition to get the best properties is 5 % LDPE : 95 % ABS

Effect of Modified Red Pottery Clay on the Moisture Absorption Behavior and Weatherability of Polyethylene-Based Wood-Plastic Composites

Directory of Open Access Journals (Sweden)

Qingde Li

2017-01-01

Full Text Available Red pottery clay (RPC was modified using a silane coupling agent, and the modified RPC (mRPC was then used to enhance the performance of high-density polyethylene-based wood-plastic composites. The effect of the mRPC content on the performances of the composites was investigated through Fourier transform infrared spectrometry, differential mechanical analysis (DMA and ultraviolet (UV-accelerated aging tests. After adding the mRPC, a moisture adsorption hysteresis was observed. The DMA results indicated that the mRPC effectively enhanced the rigidity and elasticity of the composites. The mRPC affected the thermal gravimetric, leading to a reduction of the thermal degradation rate and a right-shift of the thermal degradation peak; the initial thermal degradation temperature was increased. After 3000 h of UV-accelerated aging, the flexural strength and impact strength both declined. For aging time between 0 and 1000 h, the increase in amplitude of ΔL* (luminescence and ΔE* (color reached a maximum; the surface fading did not became obvious. ΔL* and ΔE* increased more significantly between 1000 and 2000 h. These characterization results indicate that the chromophores of the mRPC became briefly active. However, when the aging times were higher than 2000 h, the photo-degradation reaction was effectively prevented by adding the mRPC. The best overall enhancement was observed for an mRPC mass percentage of 5%, with a storage modulus of 3264 MPa and an increase in loss modulus by 16.8%, the best anti-aging performance and the lowest degree of color fading.

Production and Mechanical Characterization of Ballistic Thermoplastic Composite Materials

OpenAIRE

D. Korsacilar; C. Atas

2014-01-01

In this study, first thermoplastic composite materials /plates that have high ballistic impact resistance were produced. For this purpose, the thermoplastic prepreg and the vacuum bagging technique were used to produce a composite material. Thermoplastic prepregs (resin-impregnated fiber) that are supplied ready to be used, namely high-density polyethylene (HDPE) was chosen as matrix and unidirectional glass fiber was used as reinforcement. In order to compare the fiber c...

Radiation Induced Crosslinking of Polyethylene in the Presence of Bifunctional Vinyl Monomers

DEFF Research Database (Denmark)

Joshi, M. S.; Singer, Klaus Albert Julius; Silverman, J.

1977-01-01

Several reports have been published showing that the radiation induced grafting of bifunctional vinyl monomers to low density polyethylene results in a product with an unusually high density of crosslinks. The same grafting reactions are shown to reduce the incipient gel dose by more than a factor...... of fifty. This paper is concerned with the apparent crosslinking produced by the radiation grafting of two monomers to polyethylene: acrylic acid and acrylonitrile....

Evaluation and modeling of the eutectic composition of various drug-polyethylene glycol solid dispersions.

Science.gov (United States)

Baird, Jared A; Taylor, Lynne S

2011-06-01

The purpose of this study was to gain a better understanding of which factors contribute to the eutectic composition of drug-polyethylene glycol (PEG) blends and to compare experimental values with predictions from the semi-empirical model developed by Lacoulonche et al. Eutectic compositions of various drug-PEG 3350 solid dispersions were predicted, assuming athermal mixing, and compared to experimentally determined eutectic points. The presence or absence of specific interactions between the drug and PEG 3350 were investigated using Fourier transform infrared (FT-IR) spectroscopy. The eutectic composition for haloperidol-PEG and loratadine-PEG solid dispersions was accurately predicted using the model, while predictions for aceclofenac-PEG and chlorpropamide-PEG were very different from those experimentally observed. Deviations in the model prediction from ideal behavior for the systems evaluated were confirmed to be due to the presence of specific interactions between the drug and polymer, as demonstrated by IR spectroscopy. Detailed analysis showed that the eutectic composition prediction from the model is interdependent on the crystal lattice energy of the drug compound (evaluated from the melting temperature and the heat of fusion) as well as the nature of the drug-polymer interactions. In conclusion, for compounds with melting points less than 200°C, the model is ideally suited for predicting the eutectic composition of systems where there is an absence of drug-polymer interactions.

Modulation of Protein Adsorption and Cell Proliferation on Polyethylene Immobilized Graphene Oxide Reinforced HDPE Bionanocomposites.

Science.gov (United States)

Upadhyay, Rahul; Naskar, Sharmistha; Bhaskar, Nitu; Bose, Suryasarathi; Basu, Bikramjit

2016-05-18

The uniform dispersion of nanoparticles in a polymer matrix, together with an enhancement of interfacial adhesion is indispensable toward achieving better mechanical properties in the nanocomposites. In the context to biomedical applications, the type and amount of nanoparticles can potentially influence the biocompatibility. To address these issues, we prepared high-density polyethylene (HDPE) based composites reinforced with graphene oxide (GO) by melt mixing followed by compression molding. In an attempt to tailor the dispersion and to improve the interfacial adhesion, we immobilized polyethylene (PE) onto GO sheets by nucleophilic addition-elimination reaction. A good combination of yield strength (ca. 20 MPa), elastic modulus (ca. 600 MPa), and an outstanding elongation at failure (ca. 70%) were recorded with 3 wt % polyethylene grafted graphene oxide (PE-g-GO) reinforced HDPE composites. Considering the relevance of protein adsorption as a biophysical precursor to cell adhesion, the protein adsorption isotherms of bovine serum albumin (BSA) were determined to realize three times higher equilibrium constant (Keq) for PE-g-GO-reinforced HDPE composites as compared to GO-reinforced composites. To assess the cytocompatibility, we grew osteoblast cell line (MC3T3) and human mesenchymal stem cells (hMSCs) on HDPE/GO and HDPE/PE-g-GO composites, in vitro. The statistically significant increase in metabolically active cell over different time periods in culture for up to 6 days in MC3T3 and 7 days for hMSCs was observed, irrespective of the substrate composition. Such observation indicated that HDPE with GO or PE-g-GO addition (up to 3 wt %) can be used as cell growth substrate. The extensive proliferation of cells with oriented growth pattern also supported the fact that tailored GO addition can support cellular functionality in vitro. Taken together, the experimental results suggest that the PE-g-GO in HDPE can effectively be utilized to enhance both mechanical and

Structural and magnetic characterization of copper sulfonated phthalocyanine grafted onto treated polyethylene

Energy Technology Data Exchange (ETDEWEB)

Reznickova, A., E-mail: alena.reznickova@vscht.cz [Department of Solid State Engineering, University of Chemistry and Technology, 166 28, Prague 6 (Czech Republic); Kolska, Z. [Department of Solid State Engineering, University of Chemistry and Technology, 166 28, Prague 6 (Czech Republic); Faculty of Science, J.E. Purkyne University, 400 96 Usti nad Labem (Czech Republic); Orendac, M.; Cizmar, E. [Faculty of Science, P.J. Safarik University, Park Angelinum 9, 04013 Kosice (Slovakia); Sajdl, P. [Department of Power Engineering, University of Chemistry and Technology, 166 28, Prague 6 (Czech Republic); Svorcik, V. [Department of Solid State Engineering, University of Chemistry and Technology, 166 28, Prague 6 (Czech Republic)

2016-08-30

Highlights: • Polyethylene (PE) surface was activated by argon plasma discharge. • Monolayer of copper phthalocyanine was achieved. • ESR proved that CuPc coated PE surface exhibits magnetic properties. • The studied structures may have potential application in spintronics and data storage. - Abstract: This study focuses on high density polyethylene (HDPE) activated by Ar plasma treatment, subsequently grafted with copper sulfonated phthalocyanine (CuPc) especially pointing out to the surface and magnetic properties of those composites. Properties of pristine PE and their plasma treated counterparts were studied by different experimental techniques: X-ray photoelectron spectroscopy (XPS), UV–vis spectroscopy, zeta potential and by electron spin resonance (ESR). XPS analysis confirmed the successful grafting of phthalocyanine. The highest absorption was found for the sample grafted with {sup b}CuPc for 1 h. Electrokinetic analysis also confirmed the plasma treatment and also subsequent CuPc grafting influence significantly the surface chemistry and charge. These results correspond well with XPS determination. ESR studies confirmed the presence of CuPc grafted on HDPE. It was found, that grafting is mediated by magnetically inactive functional groups, rather than radicals. Magnetic properties of CuPc do not seem to change significantly after grafting CuPc on polyethylene surface.

Correlation between Onset Oxidation Temperature (OOT) and Fourier Transform Infrared Spectroscopy (FTIR) for monitoring the restabilization of Recycled Low-density Polyethylene (LDPE)

Energy Technology Data Exchange (ETDEWEB)

Ruvolo-Filho, Adhemar; Pelozzi, Tadeu Luiz Alonso, E-mail: adhemar@power.ufscar.br [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Departamento de Quimica

2013-07-01

In this work a new method was developed for monitoring the oxidative stability of restabilized and non-restabilized low-density polyethylene (LDPE) during multiple extrusion cycles. The method is based on correlations between Fourier Transform Infrared Spectroscopy (FTIR) and Onset Oxidation Temperature (OOT). Non-linear calibration curves correlating the concentration of primary or secondary antioxidants and the OOT values were obtained. (author)

Comparison of mechanical properties of multi-walled carbon nanotube and graphene nanosheet/polyethylene oxide composites plasticized with lithium triflate

Science.gov (United States)

Jurkane, A.; Gaidukov, S.

2017-10-01

A strong engineering interest in nanostructured conducting polymers and its composite materials have been widely used to build various sensor devices, electronic interconnect devices, fuel cells and batteries. Preparation of polymeric nano-composites with finely controlled structure, especially, at nano-scale, is still one of the most perspective modification ways of the properties of polymeric composites. Multi-walled carbon nanotube (MWCNT)/polyethylene oxide (PEO) and graphene nanosheets (GR)/PEO composites and composite of MWCNT/GR/PEO were prepared by solution casting and hot-pressing method. Composites were plasticized by 5% of Lithium triflate (LiTrifl), which play role of additional ion source in conducting polymer composite. Mechanical tensile tests were performed to evaluate nanoparticles influence on the mechanical strength of the conductive polymer composite materials. Difference of tensile tests of prepared composition can be seen from tensile tests data curves. The results of tensile tests indicated that the nanoparticles can provide PEO/5%LiTrifl composite with stiffening effects at rather low filler content (at least 0.05% by volume).

Dodecylamine functionalization of carbon nanotubes to improve dispersion, thermal and mechanical properties of polyethylene based nanocomposites

Science.gov (United States)

Ferreira, F. V.; Franceschi, W.; Menezes, B. R. C.; Brito, F. S.; Lozano, K.; Coutinho, A. R.; Cividanes, L. S.; Thim, G. P.

2017-07-01

This study presents the effect of dodecylamine (DDA) functionalization of carbon nanotubes (CNTs) on the thermo-physical and mechanical properties of high-density polyethylene (HDPE) based composites. Here, we showed that the functionalization with DDA improved the dispersion of the CNTs as well as the interfacial adhesion with the HDPE matrix via non-covalent interactions. The better dispersion and interaction of CNT in the HDPE matrix as a function of the surface chemistry was correlated with the improved thermo-physical and mechanical properties.

Fatigue resistance, debonding force, and failure type of fiber-reinforced composite, polyethylene ribbon-reinforced, and braided stainless steel wire lingual retainers in vitro

NARCIS (Netherlands)

Foek, Dave Lie Sam; Yetkiner, Enver; Ozcan, Mutlu

Objective: To analyze the fatigue resistance, debonding force, and failure type of fiber-reinforced composite, polyethylene ribbon-reinforced, and braided stainless steel wire lingual retainers in vitro. Methods: Roots of human mandibular central incisors were covered with silicone, mimicking the

Aqueous preparation of polyethylene glycol/sulfonated graphene phase change composite with enhanced thermal performance

International Nuclear Information System (INIS)

Li, Hairong; Jiang, Ming; Li, Qi; Li, Denian; Chen, Zongyi; Hu, Waping; Huang, Jing; Xu, Xizhe; Dong, Lijie; Xie, Haian; Xiong, Chuanxi

2013-01-01

Highlights: • We report an aqueous preparation technique of PEG/graphene phase change composite. • Hydrophilic sulfonated graphene (SG) nanosheets were synthesized. • Large increase in thermal conductivity is attained at low SG loading. • High latent heat is retained due to the low filler loading. • Affinity between SG and PEG contributes to the enhanced thermal performance. - Abstract: A polyethylene glycol (PEG)/sulfonated graphene (SG) phase change composite with enhanced thermal performance was prepared by solution processing in aqueous medium. It is remarkable that the addition of only 4 wt.% of SG to PEG could lead to a four times higher increase in thermal conductivity and a slight decrease in the phase change enthalpy, which is attributed to the formation of efficient thermal conductive network within the PEG matrix relevant to the excellent thermal property and unique 2-dimensional morphology of graphene as well as strong interface affinity between PEG matrix and SG nanosheets. The aqueous preparation technique is expected to pioneer a new way to prepare environment friendly organic phase change materials, and the production of PEG/SG composites is potentially scalable due to the facile fabricating process

Polyethylene/synthetic boehmite alumina nanocomposites: Structure, thermal and rheological properties

Directory of Open Access Journals (Sweden)

2010-05-01

Full Text Available Synthetic boehmite alumina (BA has been incorporated up to 8 wt% in low density polyethylene (LDPE and high density polyethylene (HDPE, respectively, by melt compounding. The primary nominal particle size of these two BA grades was 40 and 60 nm, respectively. The dispersion of the BA in polyethylene (PE matrices was investigated by scanning and transmission electron microscopy techniques (SEM and TEM. The thermal (melting and crystallization, thermooxidative (oxidation induction temperature and time, and rheological behaviors of the nanocomposites were determined. It was found that BA is nanoscale dispersed in both LDPE and HDPE without any surface treatment and additional polymeric compatibilizer. BA practically did not influence the thermal (melting and crystallization and rheological properties of the parent PEs. On the other hand, BA worked as a powerful thermooxidative stabilizer for LDPE, and especially for HDPE nanocomposites.

POLYETHYLENE ENCAPSULATION

International Nuclear Information System (INIS)

Kalb, P.

2001-01-01

(NRC, 1991; 1983) Because polyethylene is a relatively new material, it is difficult to predict its long-term durability. However, prior to scale-up of the microencapsulation process, a study was conducted to evaluate potential degradation mechanisms. The study examined potential effects on mechanical integrity from exposure to chemicals and solvents, thermal cycling, saturated environments, microbial attack, and high gamma-radiation fields (Kalb et al., 1991). At ambient temperatures, polyethylene is relatively inert to most chemicals, including organic solvents, acids, and alkaline solutions. Exposure to changes in temperature or saturated soil conditions have been shown to degrade the mechanical integrity of some waste forms, but had little or no measurable impact on polyethylene waste forms. Low-density polyethylene is not susceptible to growth of microbial organisms, a fact that is evidenced by the lack of plastics decomposition in municipal waste landfills. When exposed to gamma-radiation at total doses of up to lo8 rad, additional cross-linking of the polymer occurs, resulting in increased strength and lower leachability

Assessment of low density polyethylene characteristics for hazardous waste immobilization; Avaliacao das caracteristicas do polietileno de baixa densidade visando a imobilizacao de rejeitos perigosos

Energy Technology Data Exchange (ETDEWEB)

Cota, Stela; Carvalho, Larissa Lara de; Pacheco, Graziella Rajao Cota; Oliveira, Tania Valeria de; Senne Junior, Murillo; Pacheco, Raquel R. Janot [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil)]. E-mail: sdsc@cdtn.br

2005-07-01

This paper analyses the properties of low density polyethylene (LDPE) to allow choosing the more suitable to be used as matrices for radioactive and hazardous waste immobilization. Four virgin and recycled LDPE, with different melting index, were evaluated by extrusion and compressive strength tests. A preliminary immobilization test has been carried out using a simulated waste and one of the evaluated polymers and the homogeneity of the final waste product was determinate by the analysis of the material density. (author)

Graphite-high density polyethylene laminated composites with high thermal conductivity made by filament winding

Directory of Open Access Journals (Sweden)

W. Lv

2018-03-01

Full Text Available The low thermal conductivity of polymers limits their use in numerous applications, where heat transfer is important. The two primary approaches to overcome this limitation, are to mix in other materials with high thermal conductivity, or mechanically stretch the polymers to increase their intrinsic thermal conductivity. Progress along both of these pathways has been stifled by issues associated with thermal interface resistance and manufacturing scalability respectively. Here, we report a novel polymer composite architecture that is enabled by employing typical composites manufacturing method such as filament winding with the twist that the polymer is in fiber form and the filler in form of sheets. The resulting novel architecture enables accession of the idealized effective medium composite behavior as it minimizes the interfacial resistance. The process results in neat polymer and 50 vol% graphite/polymer plates with thermal conductivity of 42 W·m–1·K–1 (similar to steel and 130 W·m–1·K–1 respectively.

Radiation Shielding of Lunar Regolith/Polyethylene Composites and Lunar Regolith/Water Mixtures

Science.gov (United States)

Johnson, Quincy F.; Gersey, Brad; Wilkins, Richard; Zhou, Jianren

2011-01-01

Space radiation is a complex mixed field of ionizing radiation that can pose hazardous risks to sophisticated electronics and humans. Mission planning for lunar exploration and long duration habitat construction will face tremendous challenges of shielding against various types of space radiation in an attempt to minimize the detrimental effects it may have on materials, electronics, and humans. In late 2009, the Lunar Crater Observation and Sensing Satellite (LCROSS) discovered that water content in lunar regolith found in certain areas on the moon can be up to 5.6 +/-2.8 weight percent (wt%) [A. Colaprete, et. al., Science, Vol. 330, 463 (2010). ]. In this work, shielding studies were performed utilizing ultra high molecular weight polyethylene (UHMWPE) and aluminum, both being standard space shielding materials, simulated lunar regolith/ polyethylene composites, and simulated lunar regolith mixed with UHMWPE particles and water. Based on the LCROSS findings, radiation shielding experiments were conducted to test for shielding efficiency of regolith/UHMWPE/water mixtures with various percentages of water to compare relative shielding characteristics of these materials. One set of radiation studies were performed using the proton synchrotron at the Loma Linda Medical University where high energy protons similar to those found on the surface of the moon can be generated. A similar experimental protocol was also used at a high energy spalation neutron source at Los Alamos Neutron Science Center (LANSCE). These experiments studied the shielding efficiency against secondary neutrons, another major component of space radiation field. In both the proton and neutron studies, shielding efficiency was determined by utilizing a tissue equivalent proportional counter (TEPC) behind various thicknesses of shielding composite panels or mixture materials. Preliminary results from these studies indicated that adding 2 wt% water to regolith particles could increase shielding of

Supercritical CO2 foaming of radiation crosslinked polypropylene/high-density polyethylene blend: Cell structure and tensile property

Science.gov (United States)

Yang, Chenguang; Xing, Zhe; Zhang, Mingxing; Zhao, Quan; Wang, Mouhua; Wu, Guozhong

2017-12-01

A blend of isotactic polypropylene (PP) with high-density polyethylene (HDPE) in different PP/HDPE ratios was irradiated by γ-ray to induce cross-linking and then foamed using supercritical carbon dioxide (scCO2) as a blowing agent. Radiation effect on the melting point and crystallinity were analyzed in detail. The average cell diameter and cell density were compared for PP/HDPE foams prepared under different conditions. The optimum absorbed dose for the scCO2 foaming of PP/HDPE in terms of foaming ability and cell structure was 20 kGy. Tensile measurements showed that the elongation at break and tensile strength at break of the crosslinked PP/HDPE foams were higher than the non-crosslinked ones. Of particular interest was the increase in the foaming temperature window from 4 ℃ for pristine PP to 8-12 ℃ for the radiation crosslinked PP/HDPE blends. This implies much easier handling of scCO2 foaming of crosslinked PP with the addition of HDPE.

Density of biogas digestate depending on temperature and composition.

Science.gov (United States)

Gerber, Mandy; Schneider, Nico

2015-09-01

Density is one of the most important physical properties of biogas digestate to ensure an optimal dimensioning and a precise design of biogas plant components like stirring devices, pumps and heat exchangers. In this study the density of biogas digestates with different compositions was measured using pycnometers at ambient pressure in a temperature range from 293.15 to 313.15K. The biogas digestates were taken from semi-continuous experiments, in which the marine microalga Nannochloropsis salina, corn silage and a mixture of both were used as feedstocks. The results show an increase of density with increasing total solid content and a decrease with increasing temperature. Three equations to calculate the density of biogas digestate were set up depending on temperature as well as on the total solid content, organic composition and elemental composition, respectively. All correlations show a relative deviation below 1% compared to experimental data. Copyright © 2015. Published by Elsevier Ltd.

Study of positron annihilation lifetime spectroscopy in carbon black-filled HDPE composite

CERN Document Server

Zhang Xian Feng; Zhou Xian Yi; Weng Hu Imin; Ye Bang Jiao; Han Rong Dian; Jia Shao Jin; Zhang Zhi Cheng

2002-01-01

The variation of the electrical conductivity of high density polyethylene (HDPE) with the carbon black (CB) content was studied using positron annihilation lifetime spectroscopy (PALS) and free-volume model, the crystallinity of HDPE/CB composite and 'percolation' effect were discussed with measurements of conductivity and DSC test

Solid-state poly(ethylene glycol)-polyurethane/polymethylmethacrylate/rutile TiO2 nanofiber composite electrolyte-correlation between morphology and conducting properties

International Nuclear Information System (INIS)

Chilaka, Naresh; Ghosh, Sutapa

2012-01-01

Highlights: ► Semi IPN composite of PEG-PU/PMMA with different wt% of rutile TiO 2 is synthesized. ► Formation of nanocomposite is confirmed by SEM, XRD and IR spectroscopic analysis. ► DSC and TGA confirmed the enhanced thermal stability of the composite. ► Composite with 18 wt% rutile TiO 2 is found to be the best conducting material. - Abstract: A series of lithium electrolyte materials based on hybrid of semi Inter penetrating Polymer Network of [poly(ethylene glycol)-polyurethane-polymethylmethacrylate] [60:40] and TiO 2 nanofibers is described. TiO 2 nanofibers are made by simple solvothermal procedure. Rutile phase of TiO 2 and its fibrous morphology are confirmed by X-ray diffraction pattern and scanning electron microscopy image respectively. Semi Inter penetrating Polymer Network of polyethylene glycol-polyurethane/polymethylmethacrylate with LiClO 4 and its nanocomposite with different weight percent of TiO 2 nano fibers have been synthesized. The formation of Inter penetrating Polymer Network and its amorphous nature are confirmed by Fourier transform infrared spectra, X-ray diffraction pattern and differential scanning calorimetry results. Thermo gravimetric analysis shows enhanced thermal stability of the composite compared to the semi Inter penetrating Polymer Network system. The electrical characterizations of the nanocomposites are done by current–voltage (I–V) measurements and impedance spectroscopy. These results confirm that incorporation of TiO 2 nanofibers by 18% enhances the conductivity of the Inter penetrating Polymer Network system by ten times . The nanoscale structure of the inorganic material is found to be responsible for the bulk properties of the system, especially those that differ from the properties of similar, pure salt-in-polymer electrolytes. Further differential scanning calorimetry, scanning electron microscopy and impedance data confirm the presence of two polymeric phases in the semi Inter penetrating Polymer

The potential of bamboo in the design of polymer composites

Directory of Open Access Journals (Sweden)

Patrícia Santos Delgado

2012-08-01

Full Text Available Bamboo is an alternative sustainable material for use in product design and has been incorporated into the concepts of eco-design. Here, we investigated the mechanical properties and morphologies of low density polyethylene (LDPE/bamboo flour (BF composites that were modified with polyethylene-graft-maleic anhydride (PE-g-MA and glycerol. Scanning electron microscopy (SEM and tensile tests of the composites demonstrated poor adhesion between the filler and matrix. Contact angle measurement showed that the surface of LDPE was modified by the presence of the load. The thermal stability of the composites was studied by measuring the oxidation induction time (OIT. Preliminary bacterial penetration tests were performed using culture inoculums of E. coli and S. aureus to investigate the natural antibacterial and bacteriostatic properties attributed to bamboo. Furthermore, bamboo may have interesting antioxidant activity with potential for use in food packaging applications.

Electrically and Thermally Conductive Low Density Polyethylene-Based Nanocomposites Reinforced by MWCNT or Hybrid MWCNT/Graphene Nanoplatelets with Improved Thermo-Oxidative Stability

OpenAIRE

Sandra Paszkiewicz; Anna Szymczyk; Daria Pawlikowska; Jan Subocz; Marek Zenker; Roman Masztak

2018-01-01

In this paper, the electrical and thermal conductivity and morphological behavior of low density polyethylene (LDPE)/multi-walled carbon nanotubes (MWCNTs) + graphene nanoplatelets (GNPs) hybrid nanocomposites (HNCs) have been studied. The distribution of MWCNTs and the hybrid of MWCNTs/GNPs within the polymer matrix has been investigated with scanning electron microscopy (SEM). The results showed that the thermal and electrical conductivity of the LDPE-based nanocomposites increased along wi...

Characterization of laser beam transmission through a High Density Polyethylene (HDPE) plate

Science.gov (United States)

Genna, S.; Leone, C.; Tagliaferri, V.

2017-02-01

Infrared (IR) light propagation in semicrystalline polymers involves mechanisms such as reflection, transmission, absorption and internal scattering. These different rates determine either the interaction mechanism, either the temperatures reached in the IR heating processes. Consequently, the knowledge of these rates is fundamental in the development of IR heating processes in order to avoid the polymer's damage and to increase the process energy efficiency. Aim of this work is to assess a simple procedure to determine the rates of absorbed, reflected, transmitted and scattered energy in the case of an unfilled High Density Polyethylene (HDPE) plate. Experimental tests were performed by exposing a HDPE plate, 3 mm in thickness, to a diode laser source, working at the fundamental wavelength of 975 nm. The transmitted power was measured by power meter, the reflected one by applying the Beer-Lambert law to sample of different thickness. IR thermal images were adopted to measure the absorbed ratio. The scattered ratio was measured by energetic balance, as difference between the incoming power and the other ratios. Finally, IR thermal images were adopted to measure the scattered ratio and to validate the procedure.

Characterization of radiation-cross-linked, high-density polyethylene for thermal energy storage

International Nuclear Information System (INIS)

Whitaker, R.B.; Craven, S.M.; Etter, D.E.; Jendrek, E.F.; Nease, A.B.

1983-01-01

Electron beam cross-linked high-density polyethylene (HDPE) pellets (DuPont Alathon, 0.93 MI) have been characterized for potential utility in thermal energy storage applications, before and after up to 500 melt-freeze cycles in ethylene glycol. Up to 95% of the HDPE's initial DSC differential scanning calorimetry Δ H/sub f/ value (44.7 cal/g) (at 1.25 0 C/min cooling rates) was retained up to 9.0 Mrad radiation dosage. Form-stability after 500 melt-freeze cycles was very good at this dosage level. X-ray diffraction measurements showed little difference between irradiated HDPE's and the unirradiated control, indicating that cross-linking occurred primarily in the amorphous regions. FTIR spectroscopy showed the pellets to be uniformly reacted. The ratios of the 965-cm -1 absorption band (trans RCH=CRH') to the 909-cm -1 band (RCH=CH 2 ) increased with increasing radiation dosage, up to 18 Mrad. Gel contents reached a maximum of 75% at the 13.5 Mrad dosage, indicating that other reactions, in addition to cross-linking, occurred at the highest (18 Mrad) dosage level. 15 references, 5 figures, 4 tables

Effect of titanium dioxide (TiO2) on largely improving solar reflectance and cooling property of high density polyethylene (HDPE) by influencing its crystallization behavior

International Nuclear Information System (INIS)

Wang, Shichao; Zhang, Jun

2014-01-01

Highlights: • HDPE/TiO 2 composites have more perfect crystal structure. • Refractive index is the key factor affecting the final solar reflectance. • HDPE/TiO 2 composites can achieve high solar reflectance. • The real cooling property is in accordance with solar reflectance. - Abstract: In this study, the different crystal forms of titanium dioxide (TiO 2 ) were added into high density polyethylene (HDPE) to fabricate cool material. Crystal structure, crystallization behavior, crystal morphology were investigated by wide angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC) and polarized optical microscope (POM). Scanning electron microscope (SEM) was applied to observe dispersion of TiO 2 particles in the HDPE matrix and the cross section morphology. The solar reflectance and actual cooling property were evaluated by UV–Vis–NIR spectrometer and a self-designed device. By adding TiO 2 particles into HDPE matrix, the polymer chain could crystallize into more perfect and thermal stable lamella. The presence of TiO 2 particles dramatically increased the number of nucleation site therefore decreased the crystal size. The subsequent solar reflectance was related to the degree of crystallinity, the spherulite size of HDPE, refractive index, and distribution of TiO 2 particles in HDPE matrix. It was found the rutile TiO 2 could largely improve the total solar reflectance from 28.2% to 51.1%. Finally, the temperature test showed that the composites had excellent cooling property, which was in accordance with solar reflectance result

Surface characterization of weathered wood-plastic composites produced from modified wood flour

Science.gov (United States)

James S. Fabiyi; Armando G. McDonald; Nicole M. Stark

2007-01-01

The effects of weathering on the surface properties of wood-plastic composites (WPC) were examined. High-density polyethylene (HDPE) based WPCs made from modified wood flour (untreated, extractives free, and holocellulose (delignified) fibers) were subjected to accelerated (xenon-arc) weathering. Colorimetry and Fourier-transform infrared spectroscopy were employed to...

Influence of different factors on the destruction of films based on polylactic acid and oxidized polyethylene

Science.gov (United States)

Podzorova, M. V.; Tertyshnaya, Yu. V.; Pantyukhov, P. V.; Shibryaeva, L. S.; Popov, A. A.; Nikolaeva, S.

2016-11-01

Influence of different environmental factors on the degradation of film samples based on polylactic acid and low density polyethylene with the addition of oxidized polyethylene was studied in this work. Different methods were used to find the relationship between degradation and ultraviolet, moisture, oxygen. It was found that the addition of oxidized polyethylene, used as a model of recycled polyethylene, promotes the degradation of blends.

Thermal, tensile and rheological properties of low density polyethylene (LDPE) processed irradiated by gamma-ray

International Nuclear Information System (INIS)

Ferreto, Helio F.R.; Oliveira, Ana C.F. de; Parra, Duclerc F.; Lugao, Ademar B.

2013-01-01

The aim of this paper is to investigate structural changes of low density polyethylene (LDPE) modified by ionizing radiation (gamma rays). The gamma radiation process for modification of commercial polymers is a widely applied technique to promote new physical-chemical and mechanical properties. Gamma irradiation originates free radicals which can induce chain scission or recombination, providing its annihilation, branching or crosslinking. The samples were prepare in hydraulic press in temperature 180 deg C after was irradiated with gamma source of 60 Co at doses of 5, 10, 20, 50 or 100 kGy at a dose rate of 5 kGy/h in inert atmosphere. The changes in molecular structure of LDPE, after gamma irradiations were evaluated using thermogravimetric analysis (TGA) and tensile machine and oscillatory rheology. The results showed the variations of the properties depending on the dose at each atmosphere. (author)

Properties of concrete modified with waste Low Density Polyethylene and saw dust ash

Science.gov (United States)

Srimanikandan, P.; Sreenath, S.

2017-07-01

The increase in industrialization creates need for disposal of large quantity of by-products. To overcome the difficulty of disposal, these by-products can be used as a replacement for raw material. In this concern, non-conventional industrial wastes such as plastic bags, PET bottles, pulverized waste Low Density Polyethylene (LDPE) and biological waste such as saw-dust ash, coconut coir were used as a replacement in concrete. In this project, saw-dust ash and pulverized waste LDPE were introduced as the partial replacement for cement and fine aggregates respectively. 0%, 5%, 10%, 15% and 20% of sand by volume was replaced with LDPE and 0%, 1%, 3%, 5% and 10% of cement by volume was replaced with saw dust ash. Standard cube, cylinder and prism specimens were cast to assess the compressive strength, split tensile strength and flexural strength of modified concrete after 28 days of curing. Optimum percentage of replacement was found by comparing the test results. The mix with 5% of LDPE and 3% of saw dust ash showed a better result among the other mixes.

On the sensitivity of dimensional stability of high density polyethylene on heating rate

Directory of Open Access Journals (Sweden)

2007-02-01

Full Text Available Although high density polyethylene (HDPE is one of the most widely used industrial polymers, its application compared to its potential has been limited because of its low dimensional stability particularly at high temperature. Dilatometry test is considered as a method for examining thermal dimensional stability (TDS of the material. In spite of the importance of simulation of TDS of HDPE during dilatometry test it has not been paid attention by other investigators. Thus the main goal of this research is concentrated on simulation of TDS of HDPE. Also it has been tried to validate the simulation results and practical experiments. For this purpose the standard dilatometry test was done on the HDPE speci­mens. Secant coefficient of linear thermal expansion was computed from the test. Then by considering boundary conditions and material properties, dilatometry test has been simulated at different heating rates and the thermal strain versus temper­ature was calculated. The results showed that the simulation results and practical experiments were very close together.

Reorganizing Neural Network System for Two Spirals and Linear Low-Density Polyethylene Copolymer Problems

Directory of Open Access Journals (Sweden)

G. M. Behery

2009-01-01

Full Text Available This paper presents an automatic system of neural networks (NNs that has the ability to simulate and predict many of applied problems. The system architectures are automatically reorganized and the experimental process starts again, if the required performance is not reached. This processing is continued until the performance obtained. This system is first applied and tested on the two spiral problem; it shows that excellent generalization performance obtained by classifying all points of the two-spirals correctly. After that, it is applied and tested on the shear stress and the pressure drop problem across the short orifice die as a function of shear rate at different mean pressures for linear low-density polyethylene copolymer (LLDPE at 190∘C. The system shows a better agreement with an experimental data of the two cases: shear stress and pressure drop. The proposed system has been also designed to simulate other distributions not presented in the training set (predicted and matched them effectively.

Potential Use of In Situ Material Composites such as Regolith/Polyethylene for Shielding Space Radiation

Science.gov (United States)

Theriot, Corey A.; Gersey, Buddy; Bacon, Eugene; Johnson, Quincy; Zhang, Ye; Norman, Jullian; Foley, Ijette; Wilkins, Rick; Zhou, Jianren; Wu, Honglu

2010-01-01

NASA has an extensive program for studying materials and methods for the shielding of astronauts to reduce the effects of space radiation when on the surfaces of the Moon and Mars, especially in the use of in situ materials native to the destination reducing the expense of materials transport. The most studied material from the Moon is Lunar regolith and has been shown to be as efficient as aluminum for shielding purposes (1). The addition of hydrogenous materials such as polyethylene should increase shielding effectiveness and provide mechanical properties necessary of structural materials (2). The neutron radiation shielding effectiveness of polyethylene/regolith stimulant (JSC-1A) composites were studied using confluent human fibroblast cell cultures exposed to a beam of high-energy spallation neutrons at the 30deg-left beam line (ICE house) at the Los Alamos Neutron Science Center. At this angle, the radiation spectrum mimics the energy spectrum of secondary neutrons generated in the upper atmosphere and encountered when aboard spacecraft and high-altitude aircraft. Cell samples were exposed in series either directly to the neutron beam, within a habitat created using regolith composite blocks, or behind 25 g/sq cm of loose regolith bulk material. In another experiment, cells were also exposed in series directly to the neutron beam in T-25 flasks completely filled with either media or water up to a depth of 20 cm to test shielding effectiveness versus depth and investigate the possible influence of secondary particle generation. All samples were sent directly back to JSC for sub-culturing and micronucleus analysis. This presentation is of work performed in collaboration with the NASA sponsored Center for Radiation Engineering and Science for Space Exploration (CRESSE) at Prairie View A&M.

EVALUATION OF ULTRASONIC PHASED-ARRAY FOR DETECTION OF PLANAR FLAWS IN HIGH-DENSITY POLYETHYLENE (HDPE) BUTT-FUSION JOINTS

Energy Technology Data Exchange (ETDEWEB)

Prowant, Matthew S.; Denslow, Kayte M.; Moran, Traci L.; Jacob, Rick E.; Hartman, Trenton S.; Crawford, Susan L.; Mathews, Royce; Neill, Kevin J.; Cinson, Anthony D.

2016-09-21

The desire to use high-density polyethylene (HDPE) piping in buried Class 3 service and cooling water systems in nuclear power plants is primarily motivated by the material’s high resistance to corrosion relative to that of steel and metal alloys. The rules for construction of Class 3 HDPE pressure piping systems were originally published in Code Case N-755 and were recently incorporated into the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME BPVC) Section III as Mandatory Appendix XXVI (2015 Edition). The requirements for HDPE examination are guided by criteria developed for metal pipe and are based on industry-led HDPE research or conservative calculations.

Mechanical Reinforcement of Epoxy Composites with Carbon Fibers and HDPE

Science.gov (United States)

He, R.; Chang, Q.; Huang, X.; Li, J.

2018-01-01

Silanized carbon fibers (CFs) and a high-density polyethylene with amino terminal groups (HDPE) were introduced into epoxy resins to fabricate high-performance composites. A. mechanical characterization of the composites was performed to investigate the effect of CFs in cured epoxy/HDPE systems. The composites revealed a noticeable improvement in the tensile strength, elongation at break, flexural strength, and impact strength in comparison with those of neat epoxy and cured epoxy/HDPE systems. SEM micrographs showed that the toughening effect could be explained by yield deformations, phase separation, and microcracking.

Modeling benzene permeation through drinking water high density polyethylene (HDPE) pipes.

Science.gov (United States)

Mao, Feng; Ong, Say Kee; Gaunt, James A

2015-09-01

Organic compounds such as benzene, toluene, ethyl benzene and o-, m-, and p-xylene from contaminated soil and groundwater may permeate through thermoplastic pipes which are used for the conveyance of drinking water in water distribution systems. In this study, permeation parameters of benzene in 25 mm (1 inch) standard inside dimension ratio (SIDR) 9 high density polyethylene (HDPE) pipes were estimated by fitting the measured data to a permeation model based on a combination of equilibrium partitioning and Fick's diffusion. For bulk concentrations between 6.0 and 67.5 mg/L in soil pore water, the concentration-dependent diffusion coefficients of benzene were found to range from 2.0×10(-9) to 2.8×10(-9) cm2/s while the solubility coefficient was determined to be 23.7. The simulated permeation curves of benzene for SIDR 9 and SIDR 7 series of HDPE pipes indicated that small diameter pipes were more vulnerable to permeation of benzene than large diameter pipes, and the breakthrough of benzene into the HDPE pipe was retarded and the corresponding permeation flux decreased with an increase of the pipe thickness. HDPE pipes exposed to an instantaneous plume exhibited distinguishable permeation characteristics from those exposed to a continuous source with a constant input. The properties of aquifer such as dispersion coefficients (DL) also influenced the permeation behavior of benzene through HDPE pipes.

Enhancement of high density polyethylene high integrity containers at a low level radioactive waste disposal site

International Nuclear Information System (INIS)

Sauer, R.E.; Wong, O.P.

1989-01-01

High integrity containers (HIC) made of high density polyethylene (HDPE) have been used for disposal in South Carolina since the late seventies. With the recent definitive position taken by the NRC on the suitability of these containers for disposal, alternative means of assuring the structural integrity of the containers for the long term became necessary. The authors' company has developed an utilized reinforced concrete caissons at the Hanford, Washington site as an additional barrier and structural element to assure the long term high integrity function of the current HDPE HIC's also known as Poly HIC's on the market. This paper outlines the background of the HIC's in question, the NRC positions and ruling, and presents technical bases for the applicability of appropriately designed concrete overpacks to augment the structural integrity of HIC's

Elaboration of recycled polyethylene foams reticulated by radiation

International Nuclear Information System (INIS)

Galicia M, M.

2000-01-01

In this work some obtained results are presented to make irradiation tests on recycled polymeric material (polyethylene) as well as mixtures of this with certain additive classes (foaming and reticulating agents) which will be used for the foams elaboration, objective of this work. Two types of foaming basically exist which are elaborated with low density polyethylene base. They are: a) the extruded and, b) the reticulated through ionizing radiation and chemically. Some of the properties that the expanded or foamed polyethylene are: flexibility, resistance, thermal stability, inter medium mechanical properties between the highly flexible foams and rigid among others. All of them determined by the cell type which conform them. Also was carried out the characterization of the obtained material contributing of this manner to diminish the quantity of solid wastes generated. (Author)

MANUFACTURING BIODEGRADABLE COMPOSITE MATERIALS BASED ON POLYETHYLENE AND FUNCTIONALIZED BY ALCOHOLYSIS OF ETHYLENE-VINYL ACETATE COPOLYMER

Directory of Open Access Journals (Sweden)

Aleksandr A. Shabarin

2016-06-01

Full Text Available Introduction. The continuous growth of production and consumption of plastic packaging creates a serious problem of disposal of package. This problem has ecological character, because the contents of the landfills decompose for decades, emit toxic com¬pounds and pollute the environment. The work is devoted to obtaining and investigation mechanical and rheological properties of biodegradable composite materials based on polyethylene and starch. Materials and Methods. In this work the author used polyethylene grade HDPE 273- 83 (GOST 16338-85, Sevilen brand 12206-007 (TU 6-05-1636-97 and potato starch (GOST 53876-2010 as a filler. Functionalization of sevilen was carried in the 30 % ethanol solution KOH at a temperature 80 °C during 3 hours. Compounding components was carried out at the laboratory of the two rotary mixer HAAKE PolyLab Rheomix 600 OS with rotors Banbury. Formation of plates for elastic strength and rheological studies were carried out on a hydraulic press Gibitre. Elastic and strength tests were carried out on the tensile machine the UAI-7000 M. Rheology tests were carried out on the rheometer Haake MARS III. The humidity filler (starch authors determined by the thermogravimetric method on the analyzer of moisture “Evlas-2M”. Results. It is shown, that the filler should not contain more than 7% moisture. Functionalization of ethylene with vinyl acetate copolymer (sevilen has performed by the method of alkaline alcoholysis. By the method of IC – spectroscopy the authors confirmed the presence of hydroxyl groups in the polymer. Using as a compatibilizer functionalized by the method of alcoholises has greatly ( significantly improved physical, mechanical and rheological properties of composite materials. Optimal content of sevilen (F in the compound according to the results of experiments amount 10 %. Discussion and Conclusions. Using of functionalized by the method of alcoholysis ethy-lene-vinyl acetate copolymer as a

Development of a Short-term Failure Assessment of High Density Polyethylene Pipe Welds - Application of the Limit Load Analysis -

Energy Technology Data Exchange (ETDEWEB)

Ryu, Ho-Wan; Han, Jae-Jun; Kim, Yun-Jae [Korea University, Seoul (Korea, Republic of); Kim, Jong-Sung [Sunchon National University, Suncheon (Korea, Republic of); Kim, Jeong-Hyeon; Jang, Chang-Heui [KAIST, Daejeon (Korea, Republic of)

2015-04-15

In the US, the number of cases of subterranean water contamination from tritium leaking through a damaged buried nuclear power plant pipe continues to increase, and the degradation of the buried metal piping is emerging as a major issue. A pipe blocked from corrosion and/or degradation can lead to loss of cooling capacity in safety-related piping resulting in critical issues related to the safety and integrity of nuclear power plant operation. The ASME Boiler and Pressure Vessel Codes Committee (BPVC) has recently approved Code Case N-755 that describes the requirements for the use of polyethylene (PE) pipe for the construction of Section III, Division 1 Class 3 buried piping systems for service water applications in nuclear power plants. This paper contains tensile and slow crack growth (SCG) test results for high-density polyethylene (HDPE) pipe welds under the environmental conditions of a nuclear power plant. Based on these tests, the fracture surface of the PENT specimen was analyzed, and the fracture mechanisms of each fracture area were determined. Finally, by using 3D finite element analysis, limit loads of HDPE related to premature failure were verified.

Adhesion, Growth, and Maturation of Vascular Smooth Muscle Cells on Low-Density Polyethylene Grafted with Bioactive Substances

Directory of Open Access Journals (Sweden)

Martin Parizek

2013-01-01

Full Text Available The attractiveness of synthetic polymers for cell colonization can be affected by physical, chemical, and biological modification of the polymer surface. In this study, low-density polyethylene (LDPE was treated by an Ar+ plasma discharge and then grafted with biologically active substances, namely, glycine (Gly, polyethylene glycol (PEG, bovine serum albumin (BSA, colloidal carbon particles (C, or BSA+C. All modifications increased the oxygen content, the wettability, and the surface free energy of the materials compared to the pristine LDPE, but these changes were most pronounced in LDPE with Gly or PEG, where all the three values were higher than in the only plasma-treated samples. When seeded with vascular smooth muscle cells (VSMCs, the Gly- or PEG-grafted samples increased mainly the spreading and concentration of focal adhesion proteins talin and vinculin in these cells. LDPE grafted with BSA or BSA+C showed a similar oxygen content and similar wettability, as the samples only treated with plasma, but the nano- and submicron-scale irregularities on their surface were more pronounced and of a different shape. These samples promoted predominantly the growth, the formation of a confluent layer, and phenotypic maturation of VSMC, demonstrated by higher concentrations of contractile proteins alpha-actin and SM1 and SM2 myosins. Thus, the behavior of VSMC on LDPE can be regulated by the type of bioactive substances that are grafted.

Surface modification of polyethylene by plasma

International Nuclear Information System (INIS)

Colin O, E.

2003-01-01

The products made of polyethylene (PE) go from construction materials, electric insulating until packing material. The films for bags and pack occupy 83.6% of the distribution of the market of PE approximately. The enormous quantity of PE that is generated by its indiscriminate use brings as consequence a deterioration to the atmosphere, due to the long life that they present as waste. This work is a study on the modification of low density polyethylene films. In this type of thin materials, the changes in the surface meet with largely on the conformation of the rest of the material. To induce changes that modify the surface of PE, plasmas were used with reactive atmospheres of air, oxygen and nitrogen. The experimentation that was carries out went to introduce the PE to a cylindrical reactor where it was generated the plasma of air, oxygen and nitrogen to different times of exposure. After having carried out the exposure to the plasma, it was found that in the polyethylene it modifies their morphology, crystallinity, hydrophobicity, composition and electric conductivity. The analytical techniques that were used to characterize later to the polyethylene of being in contact with the plasma were: X-ray diffraction, Scanning Electron Microscopy, Infrared spectroscopy, Electric conductivity, Angle of contact and finally Thermal Gravimetric Analysis. The content of this work it is presented in five chapters: In the chapter 1 there are presented some general concepts of plasma and of the one polymer in study PE. In the chapter 2 it is made a general revision on modification of surfaces, as well as the properties that were modified in polymeric materials that were exposed to plasma in previous works. In the chapter 3 the experimental part and the conditions used are described in the modification of the PE. Also in this chapter a brief description it is made of the used characterization techniques. The results and discussion are presented in the chapter 4. These results

Properties of a composite of polyethylene and cellulose fibers of sugarcane bagasse

International Nuclear Information System (INIS)

Romero, G.R.; Gonzalez, Maria E.

2003-01-01

One way of revalorizing agricultural wastes is to combine them with synthetic polymers to obtain adequate materials for certain purposes. In this paper, a trial was made to incorporate the maximum possible amount of lignocellulose fibers from sugarcane bagasse into a polyethylene matrix. The mixture was performed by means of a laboratory extruder with corotating twin screw. During the extrusion of polyethylene, the fiber was gradually added through the feeding hopper. A composition of about 50 % (w/w) of PE - fiber was obtained. Higher fiber content resulted in a lack of cohesion of the extruded material. The extruded bars were molded into 3-mm sheets by compression molding at 140 C degrees and 20 Ton. Irradiation of the molded sheets was performed with the aim of improving the material properties. Water absorption was measured according to the procedures of ASTM D 570-95, at 25 C degrees, 60 C degrees and 100 C degrees, in comparison with non-irradiated material. Less than 4 % (w/w) water absorption was measured at the higher temperatures, with no significant differences between irradiated and control samples. At 25 C degrees, after 168-h immersion, water absorption of irradiated samples was 5.3 % while control ones absorbed 6.5%. No dimensional changes were noticed after drying of the tested probes. According to these results, the material presented very good resistance to the action of water. However, no important effect was obtained by irradiation. This suggests that either the irradiation dose or the irradiation conditions were not adequate to induce an appreciable degree of crosslinking. This aspect will be studied by means of irradiation with increasing doses and measuring the crosslinking degree. Mechanical properties of obtained materials will also be studied. (author)

Steady State Simulation of Two-Gas Phase Fluidized Bed Reactors in Series for Producing Linear Low Density Polyethylene

Directory of Open Access Journals (Sweden)

Ali Farhangiyan Kashani

2012-12-01

Full Text Available A linear low density polyethylene (LLDPE production process, including two- fuidized bed reactors in series (FBRS and other process equipment, was completely simulated by Aspen Polymer Plus software. Fluidized bed reactors were considered as continuous stirred tank reactors (CSTR consisted of polymer and gas phases. POLY-SRK and NRTL-RK equations of state were used to describe polymer and non-polymer streams, respectively. In this simulation, a kinetic model, based on a double active site heterogeneous Ziegler-Natta catalyst was used for simulation of LLDPE process consisting of two FBRS. Simulator using this model has the capability to  predict a number of  principal characteristics of LLDPE such as melt fow index (MFI, density, polydispersity index, numerical and weight average molecular weights (Mn,Mw and copolymer molar fraction (SFRAC. The results of the simulation were compared with industrial plant data and a good agreement was observed between the predicted model and plant data. The simulation results show the relative error of about 0.59% for prediction of polymer mass fow and 2.67% and 0.04% for prediction of product MFI and density, respectively.

Melt density and the average composition of basalt

Science.gov (United States)

Stolper, E.; Walker, D.

1980-01-01

Densities of residual liquids produced by low pressure fractionation of olivine-rich melts pass through a minimum when pyroxene and plagioclase joint the crystallization sequence. The observation that erupted basalt compositions cluster around the degree of fractionation from picritic liquids corresponding to the density minimum in the liquid line of descent may thus suggest that the earth's crust imposes a density fiber on the liquids that pass through it, favoring the eruption of the light liquids at the density minimum over the eruption of denser more fractionated and less fractionated liquids.

Price Density Forecasts in the U.S. Hog Market: Composite Procedures

NARCIS (Netherlands)

Trujillo Barrera, A.A.; Garcia, P.; Mallory, M.

2013-01-01

Abstract We develop and evaluate quarterly out-of-sample individual and composite density forecasts for U.S. hog prices using data from 1975.I to 2010.IV. Individual forecasts are generated from time series models and the implied distribution of USDA outlook forecasts. Composite density forecasts

Surface chemistry changes of weathered HDPE/wood-flour composites studied by XPS and FTIR spectroscopy

Science.gov (United States)

Nicole M. Stark; Laurent M. Matuana

2004-01-01

The use of wood-derived fillers by the thermoplastic industry has been growing, fueled in part by the use of wood-fiber–thermoplastic composites by the construction industry. As a result, the durability of wood-fiber– thermoplastic composites after ultraviolet exposure has become a concern. Samples of 100% high-density polyethylene (HDPE) and HDPE filled with 50% wood-...

Characterization of solidified radioactive waste and container due to the incorporation of high density polyethylene granules and powder in mortar matrices

International Nuclear Information System (INIS)

Peric, A.D.

1999-01-01

Powder and granules of the high density polyethylene (PEHD) were used to prepare mortar based matrices for immobilization of radioactive waste materials containing 137 Cs, as well as containers for solidified radioactive waste form. Seven types of matrices, differ due to the percentage of granules and filler material added, were investigated. PEHD powder and granules were added to mortar matrix preparations with the objective of improving physico-chemical characteristics of the radwaste-mortar matrix mixtures, in particular the leach-rate of the immobilized radionuclide, as well as mechanical characteristics either of mortar matrix and container. In this paper, only mechanical strength aspect of the investigated mortar and concrete container formulations, is presented. The equivalent diameter of the PEHD granules used was 2.0 mm. PEHD granules were used to replace 100 volume percent of stone granules, sifted size of 2.0 mm, normally used in the matrix preparation, in order to decrease the porosity and density of the mortar matrix and to avoid segregation of the stone particles at the bottom of the immobilized radioactive waste cylindrical form. PEHD powder, particle size of 250 micrometer, was added as filler to the mortar formulation, replacing 5, 8 and 10 wt% of the total cement weight in matrix formulation and 15 and 18 wt% of the total cement weight in container formulation. Cured samples were investigated on mechanical strength, using 150 MPa hydraulic press, in order to determine influence of added polyethylene granules and powder on samples resistance to mechanical forces that solidified waste materials and concrete containers may experience at the disposal site. Results of performed investigations have shown that samples prepared with polyethylene granules, replacing 100 wt% of the stone granules, have almost twice as much mechanical strength than samples prepared with stone aggregate. Samples prepared with PEHD granules and powder have mechanical strength

Effect of annealing and biaxial deformation on the dielectric properties of composites of multiwall carbon nanotubes and poly(ethylene terephthalate)

Science.gov (United States)

Urvakis, Marius; Kupreviciute, Auste; Banys, Juras; Macutkevic, Jan; Mayoral, Beatriz; McNally, Tony

2012-01-01

The dielectric properties of composites of poly(ethylene terephthalate) (PET) with MWCNTs were investigated over a wide frequency and temperature range below and close to the electrical percolation threshold. In composites with 1 wt.% multiwall carbon nanotubes (MWCNT) inclusions, the dielectric properties below room temperature are mostly determined by β relaxation, as a consequence of the rotation of PET molecules. In stretched samples, the CNTs are oriented at about 45 deg to the stretch direction. Such deformation increased the potential for molecular rotation. However, annealing after stretching increased homogeneity of the composite and decreased the potential barrier for polymer chain rotation. Electrical conductivity effects and Maxwell-Wagner polarization mostly cause the dielectric properties of the samples with 2% MWCNT inclusions. The potential barrier for carrier tunneling is lowest in the annealed sample.

Biodegradation of films of low density polyethylene (LDPE, poly(hydroxibutyrate-co-valerate (PHBV, and LDPE/PHBV (70/30 blend with Paecilomyces variotii

Directory of Open Access Journals (Sweden)

Thayse Marques Passos

2015-02-01

Full Text Available The increased consumption of plastics in the world has been a subject of great concern and special attention by the scientific community. The aim is to promote development of materials that are biodegradable in a shorter time upon disposal in the environment. The most used synthetic plastics are difficult to biodegrade because they are made of long hydrocarbon chains, such as polyethylene (PE, polypropylene (PP, poly(vinyl chloride (PVC, which are hydrophobic and resistant to the action of microbial enzymes. The use of alternative materials (natural polyesters can minimize the harm to dumps and landfills upon their disposal, because they are susceptible to the action of microorganisms. In this study we evaluated the biodegradation/biodeterioration of PHBV (poly(3-hydroxybutyrate-co-hydroxyvalerate films, LDPE (low density polyethylene and the blend of LDPE/PHBV (70/30 by the fungus Paecilomyces variotii, using different methods: optical microscopy (OM, scanning electronic microscopy (SEM and Fourier Transform Infrared spectroscopy (FTIR.

Thermal Analysis, Mechanical and Rheological Behaviour of Melt Manufactured Polyethylene/Liquid Crystal Polymer Blends

Directory of Open Access Journals (Sweden)

Ilze ELKSNITE

2011-07-01

Full Text Available Modification of properties of conventional thermoplastics with thermotropic liquid crystal polymers, from one hand, allows decrease their viscosities, substantially facilitating processing conditions, and, from another hand, allows increase their exploitation properties. Orientation of the labile structure of liquid crystal polymer in extrusion or injection moulding causes specific reinforcement (so-called self-reinforcement to occur in the blends containing liquid crystal polymer. Up to now the effect of self-reinforcement is mostly investigated in the blends, containing considerable amount of liquid crystal polymer. In this research the effect of minor amounts of liquid crystalline co-polyester modifier on the properties of polyethylene is investigated. Various compositions of laboratory synthesized hydroxybenzoic acid /polyethylene terephtalate copolymer containing polyethylene composites have been manufactured by thermoplastic blending. It has been observed that 1 modulus of elasticity, yield strength and ultimate strength increase with raising the content of liquid crystalline modifier; 2 void content in the investigated polyethylene/liquid crystal copolymer composites is not greater that 1 %; 3 addition of liquid crystalline co-polyester modifier improves arrangement of PE crystalline phase.http://dx.doi.org/10.5755/j01.ms.17.2.483

Shape stabilised phase change materials (SSPCMs): High density polyethylene and hydrocarbon waxes

Energy Technology Data Exchange (ETDEWEB)

Mu, Mulan, E-mail: mmu01@qub.ac.uk, E-mail: m.basheer@qub.ac.uk; Basheer, P. A. M., E-mail: mmu01@qub.ac.uk, E-mail: m.basheer@qub.ac.uk [School of Planning, Architecture and Civil Engineering, Queen' s University Belfast, BT9 5AG (United Kingdom); Bai, Yun, E-mail: yun.bai@ucl.ac.uk [Department of Civil, Environmental and Geomatic Engineering, University College London, WC1E 6BT (United Kingdom); McNally, Tony, E-mail: t.mcnally@warwick.ac.uk [WMG, University of Warwick, CV4 7AL (United Kingdom)

2014-05-15

Shape stabilised phase change materials (SSPCMs) based on high density polyethylene (HDPE) with high (HPW, T{sub m}=56-58 °C) and low (L-PW, T{sub m}=18-23 °C) melting point waxes were prepared by melt-mixing in a twin-screw extruder and their potential in latent heat thermal energy storage (LHTES) applications for housing assessed. The structure and morphology of these blends were investigated by scanning electron microscopy (SEM). Both H-PW and L-PW were uniformly distributed throughout the HDPE matrix. The melting point and latent heat of the SSPCMs were determined by differential scanning calorimetry (DSC). The results demonstrated that both H-PW and L-PW have a plasticisation effect on the HDPE matrix. The tensile and flexural properties of the samples were measured at room temperature (RT, 20±2 °C) and 70 °C, respectively. All mechanical properties of HDPE/H-PW and HDPE/L-PW blends decreased from RT to 70 °C. In all instances at RT, modulus and stress, irrespective of the mode of deformation was greater for the HDPE/H-PW blends. However, at 70 °C, there was no significant difference in mechanical properties between the HDPE/H-PW and HDPE/L-PW blends.

Polyethylene solidification of low-level wastes

International Nuclear Information System (INIS)

Kalb, P.D.; Colombo, P.

1985-02-01

This topical report describes the results of an investigation on the solidification of low-level radioactive waste in polyethylene. Waste streams selected for this study included those which result from advanced volume reduction technologies (dry evaporator concentrate salts and incinerator ash) and those which remain problematic for solidification using contemporary agents (ion exchange resins). Four types of commercially available low-density polyethylenes were employed which encompass a range of processing and property characteristics. Process development studies were conducted to ascertain optimal process control parameters for successful solidification. Maximum waste loadings were determined for each waste and polyethylene type. Property evaluation testing was performed on laboratory-scale specimens to assess the potential behavior of actual waste forms in a disposal environment. Waste form property tests included water immersion, deformation under compressive load, thermal cycling and radionuclide leaching. Recommended waste loadings of 70 wt % sodium sulfate, 50 wt % boric acid, 40 wt % incinerator ash, and 30 wt % ion exchange resins, which are based on process control and waste form performance considerations are reported. 37 refs., 33 figs., 22 tabs

Hot water extracted wood fiber for production of wood plastic composites (WPCs)

Science.gov (United States)

Manuel Raul Pelaez-Samaniego; Vikram Yadama; Eini Lowell; Thomas E. Amidon; Timothy L. Chaffee

2013-01-01

Undebarked ponderosa pine chips were treated by hot water extraction to modify the chemical composition. In the treated pine (TP) , the mass was reduced by approximately 20%, and the extract was composed mainly of degradation products of hemicelluloses. Wood flour produced from TP and unextracted chips (untreated pine, UP) was blended with high-density polyethylene (...

Developing light nano-composites with improved mechanical properties for neutron shielding

Energy Technology Data Exchange (ETDEWEB)

Jamali, F. [Shiraz Univ. of Medical Sciences (Iran, Islamic Republic of). School of Medicine; Mortazavi, S.M.J. [Shiraz Univ. of Medical Sciences (Iran, Islamic Republic of). Dept. of Medical Physics and Medical Engineering; Shiraz Univ. of Medical Sciences (Iran, Islamic Republic of). The Center for Radiological Research; Kardan, M. [Nuclear Science and Technology Institute, Tehran (Iran, Islamic Republic of). Radiation Application School; Mosleh-Shirazi, M.A. [Shiraz Univ. of Medical Sciences (Iran, Islamic Republic of). Radiotherapy Dept.; Sina, S. [Shiraz Univ. of Medical Sciences (Iran, Islamic Republic of). Radiation Research Center; Rahpeyma, J.

2017-12-15

Although radiation exposures in manned space missions are normally below the limits recommended to NASA by NCRP, in long-duration deep space exploratory missions astronauts may receive relatively high doses of ionizing radiation. Novel light polyethylene-based composites can be considered as effective radiation shields in space explorations. However, normally these composites cannot provide desired mechanical properties. Over the past several years our laboratories have focused on developing efficient methods for both physical and biological protection of the crew in long term space missions. In this study carbon nanotubes and either nano-sized or micro-sized boron carbide (B{sub 4}C) fillers were incorporated into the continuous phase of low density polyethylene (LDPE). In the next phase, the mechanical characteristics of the composites as well as their neutron attenuation properties were studied. Findings of this study indicated enhanced mechanical properties accompanied by an enhanced shielding efficiency for neutrons at some specific weight fraction of the fillers.

RF magnetron sputtering and evaporation of polyisobutylene and low density polyethylene

Czech Academy of Sciences Publication Activity Database

Kousal, J.; Hanuš, J.; Choukourov, A.; Hlídek, P.; Biederman, H.; Slavinská, D.; Zemek, Josef

2005-01-01

Roč. 200, 1-4 (2005), s. 472-475 ISSN 0257-8972 R&D Projects: GA MŠk(CZ) OC 527.10; GA MŠk(CZ) ME 553 Institutional research plan: CEZ:AV0Z10100521 Keywords : magnetron * radio frequency * sputtering * polyethylene * polyisobutylene Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.646, year: 2005

Characterization of polyester composites from recycled polyethylene terephthalate reinforced with empty fruit bunch fibers

International Nuclear Information System (INIS)

Tan, Chiachun; Ahmad, Ishak; Heng, Muichin

2011-01-01

Highlights: → Unsaturated polyester resin (UPR) was synthesized from recycled PET. → Effect of surface treatment on EFB/UPR was studied. → Treatment on EFB improved the mechanical and thermal properties. → Treatment on EFB also improved fiber-matrix interaction. -- Abstract: Unsaturated polyester resin (UPR) was synthesized from recycled polyethylene terephthalate (PET) which acted as a matrix for the preparation of UPR/empty fruit bunch fibers (EFB) composite. Chemical recycling on fine pieces of PET bottles were conducted through glycolysis process using ethylene glycol. The unsaturated polyester resin (UPR) was then prepared by reacting the glycolysed product with maleic anhydride. FTIR analysis of glycolyzed product and prepared UPR showed that cross-links between unsaturated polyester chain and styrene monomer occurred at the unsaturated sites which resulted in the forming of cross-linking network. The preparation of UPR/EFB composite was carried out by adding EFB into prepared UPR matrix. The effects of surface treatment on EFB with sodium hydroxide solution (NaOH), silane coupling agent and maleic anhydride (MA) were then studied. The experimental results showed that treated EFB have higher values of tensile and impact strength compared with untreated EFB. The best results were obtained for silane treatment followed by MA and NaOH treatments where the tensile strength was increased by about 21%, 18% and 13% respectively. SEM micrographs of the tensile fracture surfaces of UPR/EFB composite also proved that treatment on EFB has increased the interfacial adhesion between the fiber and UPR matrix compared to the untreated UPR/EFB composite.

Synthesis and Properties of High Strength Thin Film Composites of Poly(ethylene Oxide and PEO-PMMA Blend with Cetylpyridinium Chloride Modified Clay

Directory of Open Access Journals (Sweden)

Mohammad Saleem Khan

2015-01-01

Full Text Available Ion-conducting thin film composites of polymer electrolytes were prepared by mixing high MW poly(ethylene oxide (PEO, poly(methyl methacrylate (PMMA as a polymer matrix, cetylpyridinium chloride (CPC modified MMT as filler, and different content of LiClO4 by using solution cast method. The crystallinity, ionic conductivity (σ, and mechanical properties of the composite electrolytes and blend composites were evaluated by using XRD, AC impedance, and UTM studies, respectively. The modification of clay by CPC showed enhancement in the d-spacing. The loading of clay has effect on crystallinity of PEO systems. Blend composites showed better mechanical properties. Young’s modulus and elongation at break values showed increase with salt and clay incorporation in pure PEO. The optimum composition composite of PEO with 3.5 wt% of salt and 3.3 wt% of CPMMT exhibited better performance.

Preparations and thermal properties of micro- and nano-BN dispersed HDPE composites

International Nuclear Information System (INIS)

Jung, Jinwoo; Kim, Jaewoo; Uhm, Young Rang; Jeon, Jae-Kyun; Lee, Sol; Lee, Hi Min; Rhee, Chang Kyu

2010-01-01

The thermal properties of micro-sized boron nitride (BN) and nano-sized BN dispersed high density polyethylene (HDPE) composites were investigated by means of differential scanning calorimetry (DSC) and thermo-gravimetric analysis (TGA). Nano-BN powder was prepared by using a ball mill process before it was mixed in HDPE. To enhance the dispersivity of nano-BN in the polymer matrix, the surfaces of the nano-particles were treated with low density polyethylene (LDPE) which was dissolved in the cyclohexane solvent. The average particle sizes of micro-BN powder and LDPE coated nano-BN powder were ∼10 μm and ∼100 nm respectively. Dispersion and distribution of 5 wt% and 20 wt% of micro-BN and nano-BN respectively mixed in HDPE were observed by using the scanning electron microscope (SEM). According to the thermal analyses of pure HDPE, micro-BN/HDPE, and nano-BN/HDPE, 20 wt% nano-BN/HDPE composite shows the lowest enthalpy of fusion (ΔH m ) and better thermal conductive characteristics compared to the others.

Biodegradation of thermally treated high-density polyethylene (HDPE) by Klebsiella pneumoniae CH001.

Science.gov (United States)

Awasthi, Shraddha; Srivastava, Pratap; Singh, Pardeep; Tiwary, D; Mishra, Pradeep Kumar

2017-10-01

Biodegradation of plastics, which are the potential source of environmental pollution, has received a great deal of attention in the recent years. We aim to screen, identify, and characterize a bacterial strain capable of degrading high-density polyethylene (HDPE). In the present study, we studied HDPE biodegradation using a laboratory isolate, which was identified as Klebsiella pneumoniae CH001 (Accession No MF399051). The HDPE film was characterized by Universal Tensile Machine (UTM), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), and Atomic Force Microscope (AFM) before and after microbial incubation. We observed that this strain was capable of adhering strongly on HDPE surface and form a thick biofilm, when incubated in nutrient broth at 30 °C on 120 rpm for 60 days. UTM analysis showed a significant decrease in weight (18.4%) and reduction in tensile strength (60%) of HDPE film. Furthermore, SEM analysis showed the cracks on the HDPE surface, whereas AFM results showed an increase in surface roughness after bacterial incubation. Overall, these results indicate that K. pneumoniae CH001 can be used as potential candidate for HDPE degradation in eco-friendly and sustainable manner in the environment.

Potential of bacteria isolated from landfill soil in degrading low density polyethylene plastic

Science.gov (United States)

Munir, E.; Sipayung, F. C.; Priyani, N.; Suryanto, D.

2018-03-01

Plastic is an important material and used for many purposes. It is returned to the environment as a waste which is recently considered as the second largest solid waste. The persistency of plastic in the environment has been attracted researchers from a different point of view. The study of the degradation of plastic using bacteria isolated from local landfill soil was conducted. Low density polyethylene (LDPE) plastic was used as tested material. Potential isolates were obtained by culturing the candidates in mineral salt medium broth containing LDPE powder. Two of ten exhibited better growth response in the selection media and were used in degradation study. Results showed that isolate SP2 and SP4 reduced the weight of LDPE film significantly to a weight loss of 10.16% and 12.06%, respectively after four weeks of incubation. Scanning electron micrograph analyses showed the surface of LDPE changed compared to the untreated film. It looked rough and cracked, and bacteria cells attached to the surface was also noticed. Fourier transform infrared spectroscopy analyses confirmed the degradation of LDPE film. These results indicated that bacteria isolated from landfill might play an important role in degrading plastic material in the landfill.

Gamma irradiation technology for composite materials

International Nuclear Information System (INIS)

Romero, Guillermo R; Gonzalez, Maria E.

2003-01-01

A composite of sugar cane bagasse and low-density polyethylene was prepared. Gamma -radiation of Cobalt-60 (Co 60 ) and reactive additives were used, to make compatible the lignocellulosic fibers with the polymeric matrix. Gamma-radiation was applied in different stages with different purposes: a) Irradiation of cellulosic fibers treated or not with reactive additive, in presence of air, to produce macro radicals increasing their reactivity during extrusion with polyethylene. A homogeneous and fusible material resulted that can be used as raw material in thermoforming processes with cost in between that of its constitutive elements; b) Irradiation of final products, to produce the cross-linking of polymeric chains. The fibers remain trapped in the cross-linked matrix. A homogeneous and infusible material with high mechanical properties was obtained. (author)

Effect of Strain Rate on Microscopic Deformation Behavior of High-density Polyethylene under Uniaxial Stretching

Directory of Open Access Journals (Sweden)

Kida Takumitsu

2017-01-01

Full Text Available The microscopic deformation behaviors such as the load sharing and the molecular orientation of high-density polyethylene under uniaxial stretching at various strain rates were investigated by using in-situ Raman spectroscopy. The chains within crystalline phase began to orient toward the stretching direction beyond the yielding region and the orientation behavior was not affected by the strain rate. While the stretching stress along the crystalline chains was also not affected by the strain rate, the peak shifts of the Raman bands at 1130, 1418, 1440 and 1460 cm-1, which are sensitive to the interchain interactions obviously, depended on the strain rate; the higher strain rates lead to the stronger stretching stress or negative pressure on the crystalline and amorphous chains. These effects of the strain rate on the microscopic deformation was associated with the cavitation and the void formation leading to the release of the internal pressure.

Release mechanisms of acetaminophen from polyethylene oxide/polyethylene glycol matrix tablets utilizing magnetic resonance imaging.

Science.gov (United States)

Tajiri, Tomokazu; Morita, Shigeaki; Sakamoto, Ryosaku; Suzuki, Masazumi; Yamanashi, Shigeyuki; Ozaki, Yukihiro; Kitamura, Satoshi

2010-08-16

Release mechanism of acetaminophen (AAP) from extended-release tablets of hydrogel polymer matrices containing polyethylene oxide (PEO) and polyethylene glycol (PEG) were achieved using flow-through cell with magnetic resonance imaging (MRI). The hydrogel forming abilities are observed characteristically and the layer thickness which is corresponding to the diffusion length of AAP has a good correlation with the drug release profiles. In addition, polymeric erosion contribution to AAP releasing from hydrogel matrix tablets was directly quantified using size-exclusion chromatography (SEC). The matrix erosion profile indicates that the PEG erosion kinetic depends primarily on the composition ratio of PEG to PEO. The present study has confirmed that the combination of in situ MRI and SEC should be well suited to investigate the drug release mechanisms of hydrogel matrix such as PEO/PEG. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Silver nanoparticles as a key feature of a plasma polymer composite layer in mitigation of charge injection into polyethylene under dc stress

International Nuclear Information System (INIS)

Milliere, L; Makasheva, K; Laurent, C; Despax, B; Boudou, L; Teyssedre, G

2016-01-01

The aim of this work is to limit charge injection from a semi-conducting electrode into low density polyethylene (LDPE) under dc field by tailoring the polymer surface using a silver nanoparticles-containing layer. The layer is composed of a plane of silver nanoparticles embedded in a semi-insulating organosilicon matrix deposited on the polyethylene surface by a plasma process. Size, density and surface coverage of the nanoparticles are controlled through the plasma process. Space charge distribution in 300 μm thick LDPE samples is measured by the pulsed-electroacoustic technique following a short term (step-wise voltage increase up to 50 kV mm −1 , 20 min in duration each, followed by a polarity inversion) and a longer term (up to 12 h under 40 kV mm −1 ) protocols for voltage application. A comparative study of space charge distribution between a reference polyethylene sample and the tailored samples is presented. It is shown that the barrier effect depends on the size distribution and the surface area covered by the nanoparticles: 15 nm (average size) silver nanoparticles with a high surface density but still not percolating form an efficient barrier layer that suppress charge injection. It is worthy to note that charge injection is detected for samples tailored with (i) percolating nanoparticles embedded in organosilicon layer; (ii) with organosilicon layer only, without nanoparticles and (iii) with smaller size silver particles (<10 nm) embedded in organosilicon layer. The amount of injected charges in the tailored samples increases gradually in the samples ranking given above. The mechanism of charge injection mitigation is discussed on the basis of complementary experiments carried out on the nanocomposite layer such as surface potential measurements. The ability of silver clusters to stabilize electrical charges close to the electrode thereby counterbalancing the applied field appears to be a key factor in explaining the charge injection

Effects of Polyethylene Grafted Maleic Anhydride on the Mechanical, Morphological, and Swelling Properties of Poly (Vinyl Chloride / Epoxidized Natural Rubber / Kenaf Core Powder Composites

Directory of Open Access Journals (Sweden)

Rohani Abdul Majid

2014-10-01

Full Text Available The effects of polyethylene grafted maleic anhydride (PE-g-MA on the properties of poly (vinyl chloride/epoxidized natural rubber (PVC/ENR kenaf core powder composites were studied, with four different loadings of kenaf core powder (5, 10, 15, and 20 phr. The tensile properties indicated that the strength and elongation at break of the composites exhibited an increase for samples with PE-g-MA. Morphological analysis using a scanning electron microscope (SEM showed better dispersion of kenaf fiber with the addition of PE-g-MA and less kenaf powder agglomeration. Furthermore, the swelling index indicated that composites with PE-g-MA showed lower toluene absorption than composites without PE-g-MA.

Effects of plasma on polyethylene fiber surface for prosthodontic application

Directory of Open Access Journals (Sweden)

Silvana Marques Miranda SPYRIDES

2015-12-01

Full Text Available ABSTRACT Plasma technology has the potential to improve the adherence of fibers to polymeric matrices, and there are prospects for its application in dentistry to reinforce the dental particulate composite. Objectives This study aimed to investigate the effect of oxygen or argon plasma treatment on polyethylene fibers. Material and Methods Connect, Construct, InFibra, and InFibra treated with oxygen or argon plasma were topographically evaluated by scanning electron microscopy (SEM, and chemically by X-ray photoelectron spectroscopy (XPS. For bending analysis, one indirect composite (Signum was reinforced with polyethylene fiber (Connect, Construct, or InFibra. The InFibra fiber was subjected to three different treatments: (1 single application of silane, (2 oxygen or argon plasma for 1 or 3 min, (3 oxygen or argon plasma and subsequent application of silane. The samples (25x2x2 mm, 6 unreinforced and 60 reinforced with fibers, were subjected to three-point loading tests to obtain their flexural strength and deflection. The results were statistically analyzed with ANOVA and the Bonferroni correction for multiple comparison tests. Results SEM analysis showed that oxygen and argon plasma treatments promote roughness on the polyethylene fiber surface. X-ray photoelectron spectroscopy (XPS analysis shows that both plasmas were effective in incorporating oxygenated functional groups. Argon or oxygen plasma treatment affected the flexural strength and deflection of a fiber reinforced composite. The application of silane does not promote an increase in the flexural strength of the reinforced composites. Conclusions Oxygen and argon plasma treatments were effective in incorporating oxygenated functional groups and surface roughness. The highest strength values were obtained in the group reinforced with polyethylene fibers treated with oxygen plasma for 3 min.

Structure development during isothermal crystallisation of high-density polyethylene: Synchrotron small-angle X-ray scattering study

International Nuclear Information System (INIS)

Ślusarczyk, Czesław

2013-01-01

Isothermal melt crystallisation in high-density polyethylene (HDPE) was studied using the time-resolved SAXS method with synchrotron radiation over a wide range of crystallisation temperatures. The SAXS profile was analysed by an interface distribution function, g 1 (r), which is a superposition of three contributions associated with the size distributions of crystalline (L C ) and amorphous (L A ) layers and a distribution of long period (LP). The morphological parameters extracted from the g 1 (r) functions show that the lamellar thickness increases with time, obeying a logarithmic time dependence. The time evolution of L C observed for the sample crystallised at 122 °C leads to the conclusion that crystallisation proceeds according to the mechanism of thickening growth. For samples crystallised at lower temperatures (116 °C and 118 °C), the lamellar thickening mechanism has been observed. The rate of lamellar thickening in these cases is much lower than that at 122 °C. At 40 °C, thickening of the crystalline layer does not occur. The interface distribution functions were deconvoluted, and the relative standard deviation σ C /L C obtained in this way is an additional parameter that is varied during crystallisation and can be used for analysis of this process. Time-dependent changes in the σ C /L C at large supercooling (T C =40 °C) indicates that L C presents a broad distribution in which the relative standard deviation increases with time. At lower supercooling (T C =122 °C), L C shows a much sharper distribution. In this case, the relative standard deviation decreases with time. - Highlights: • Isothermal melt crystallisation of high-density polyethylene (HDPE) was studied by time-resolved synchrotron small-angle X-ray scattering (SAXS) over a wide-range of supercoolings. • The SAXS profile was analysed by an interface distribution, g 1 (r), function. • At large supercooling (40 °C) the thickening of the crystalline layer does not occur. At

Tissue response to intraperitoneal implants of polyethylene oxide-modified polyethylene terephthalate.

Science.gov (United States)

Desai, N P; Hubbell, J A

1992-01-01

Polyethylene terephthalate films surface modified with polyethylene oxide of mol wt 18,500 g/mol (18.5 k) by a previously described technique, were implanted in the peritoneal cavity of mice, along with their respective untreated controls, for periods of 1-28 d. The implants were retrieved and examined for tissue reactivity and cellular adherence. The control polyethylene terephthalate surfaces showed an initial inflammatory reaction followed by an extensive fibrotic response with a mean thickness of 60 microns at 28 d. By contrast, polyethylene oxide-modified polyethylene terephthalate showed only a mild inflammatory response and no fibrotic encapsulation throughout the implantation period: at 28 d a cellular monolayer was observed. Apparently either the polyethylene oxide-modified surface was stimulating less inflammation, which was in turn stimulating less fibroblastic overgrowth, or the cellular adhesion to the polyethylene oxide-modified surface was too weak to support cellular multilayers.

Effect of titanium dioxide (TiO{sub 2}) on largely improving solar reflectance and cooling property of high density polyethylene (HDPE) by influencing its crystallization behavior

Energy Technology Data Exchange (ETDEWEB)

Wang, Shichao; Zhang, Jun, E-mail: zhangjun@njtech.edu.cn

2014-12-25

Highlights: • HDPE/TiO{sub 2} composites have more perfect crystal structure. • Refractive index is the key factor affecting the final solar reflectance. • HDPE/TiO{sub 2} composites can achieve high solar reflectance. • The real cooling property is in accordance with solar reflectance. - Abstract: In this study, the different crystal forms of titanium dioxide (TiO{sub 2}) were added into high density polyethylene (HDPE) to fabricate cool material. Crystal structure, crystallization behavior, crystal morphology were investigated by wide angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC) and polarized optical microscope (POM). Scanning electron microscope (SEM) was applied to observe dispersion of TiO{sub 2} particles in the HDPE matrix and the cross section morphology. The solar reflectance and actual cooling property were evaluated by UV–Vis–NIR spectrometer and a self-designed device. By adding TiO{sub 2} particles into HDPE matrix, the polymer chain could crystallize into more perfect and thermal stable lamella. The presence of TiO{sub 2} particles dramatically increased the number of nucleation site therefore decreased the crystal size. The subsequent solar reflectance was related to the degree of crystallinity, the spherulite size of HDPE, refractive index, and distribution of TiO{sub 2} particles in HDPE matrix. It was found the rutile TiO{sub 2} could largely improve the total solar reflectance from 28.2% to 51.1%. Finally, the temperature test showed that the composites had excellent cooling property, which was in accordance with solar reflectance result.

Flexible poly(ethylene carbonate)/garnet composite solid electrolyte reinforced by poly(vinylidene fluoride-hexafluoropropylene) for lithium metal batteries

Science.gov (United States)

He, Zijian; Chen, Long; Zhang, Bochen; Liu, Yongchang; Fan, Li-Zhen

2018-07-01

Solid-state electrolytes with high ionic conductivities, great flexibility, and easy processability are needed for high-performance solid-state rechargeable lithium batteries. In this work, we synthesize nanosized cubic Li6.25Al0.25La3Zr2O12 (LLZO) by solution combustion method and develop a flexible garnet-based composite solid electrolyte composed of LLZO, poly(ethylene carbonate) (PEC), poly(vinylidene fluoride-hexafluoropropylene) (P(VdF-HFP) and lithium bis(fluorosulfonyl)imide (LiFSI)). In the flexible composite solid electrolytes, LLZO nanoparticles, as ceramic matrix, have a positive effect on ionic conductivities and lithium ion transference number (tLi+). PEC, as a fast ion-conducting polymer, possesses high tLi+ inherently. P(VdF-HFP), as a binder, can strengthen mechanical properties. Consequently, the as-prepared composite solid electrolyte demonstrates high tLi+ (0.82) and superb thermal stability (remaining LLZO matrix after burning). All-solid-state LiFePO4|Li cells assembled with the flexible composite solid electrolyte deliver a high initial discharge specific capacity of 121.4 mAh g-1 and good cycling stability at 55 °C.

The Effect of Water Cement Ratio on Cement Brick Containing High Density Polyethylene (HDPE as Sand Replacement

Directory of Open Access Journals (Sweden)

Ali Noorwirdawati

2018-01-01

Full Text Available Waste disposal can contribute to the problem of environmental pollution. Most of the waste material is plastic based, because the nature of difficult of plastic degradable by itself. In order to overcome the problem, many study has been conducted on the reuse of plastic material into various field such as civil engineering and construction. In this study, municipal solid waste (MSW in the form of High Density Polyethylene (HDPE plastic was used to replace sand in cement sand brick production. The HDPE used in this study was obtained from a recycle factory at Nilai, Negeri Sembilan. 3% of HDPE replacement was applied in this study, with the cement-sand mix design of 1:6 and water-cement ratio 0.35, 0.40, 0.45 and 0.50 respectively. All specimens were tested for compressive strength and water absorption at 7 and 28 days. The density of the bricks was also recorded. The finding show that brick with 3% HDPE content and 0.45 of water-cement ratio at 28 days of age curing show the highest compressive strength, which is 19.5N/mm2 compared to the control specimen of 14.4 N/mm2.

Reflective Polyethylene Mulch Reduces Mexican Bean Beetle (Coleoptera: Coccinellidae) Densities and Damage in Snap Beans.

Science.gov (United States)

Nottingham, L B; Kuhar, T P

2016-08-01

Mexican bean beetle, Epilachna varivestis Mulsant, is a serious pest of snap beans, Phaseolus vulgaris L., in the eastern United States. These beetles are intolerant to direct sunlight, explaining why individuals are typically found on the undersides of leaves and in the lower portion of the plant canopy. We hypothesized that snap beans grown on reflective, agricultural polyethylene (plastic mulch) would have fewer Mexican bean beetles and less injury than those grown on black plastic or bare soil. In 2014 and 2015, beans were seeded into beds of metallized, white, and black plastic, and bare soil, in field plots near Blacksburg, VA. Mexican bean beetle density, feeding injury, predatory arthropods, and snap bean yield were sampled. Reflected light intensity, temperature, and humidity were monitored using data loggers. Pyranometer readings showed that reflected light intensity was highest over metallized plastic and second highest over white plastic; black plastic and bare soil were similarly low. Temperature and humidity were unaffected by treatments. Significant reductions in Mexican bean beetle densities and feeding injury were observed in both metallized and white plastic plots compared to black plastic and bare soil, with metallized plastic having the fewest Mexican bean beetle life stages and injury. Predatory arthropod densities were not reduced by reflective plastic. Metallized plots produced the highest yields, followed by white. The results of this study suggest that growing snap beans on reflective plastic mulch can suppress the incidence and damage of Mexican bean beetle, and increase yield in snap beans. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Electrospun nylon fibers for the improvement of mechanical properties and for the control of degradation behaviour of poly(lactide)-based composites

CSIR Research Space (South Africa)

Neppalli, R

2012-05-01

Full Text Available to the Hosemann model29 that assumes the presence of lamellar stacks having an in�nite side dimension. This assumption takes into account a monodimensional electron density change along the normal direction to the lamellae. The intensity pro�le was evaluated... features was previously noted for polyethylene and polypropylene composites �lled with polyethylene-grafted multiwall CNTs and polypropylene-grafted CNTs, respectively.34,35 A clear relationship between lamellar features and mechanical properties...

Development of Composite Made of HDPE and Fiber Reinforced Polymer Dust

International Nuclear Information System (INIS)

Muhamad Noor Izwan Ishak; Ismail Mustapha; Mohd Reusmazran Yusof; Yusof Abdullah; Nor Pai'za Mohamad Hasan; Mohamad Ridzuan Ahamad; Md Fakarudin Ab Rahman; Hafizal Yazid; Ainul Mardhiah Terry; Airwan Affandi Mahmood; Nurliyana Abdullah

2016-01-01

Full text: Composite of High Density Polyethylene and Fiber Reinforced Polymer Dust (HDPE/ FRPD) were prepared by melt mixing technique. The blend was mixed and compression molded by hydraulic press at 150 degree Celsius. Effect of blend ratio on mechanical properties of the developed composite was determined. Tensile properties of the blends found to show decreasing trend with addition of FRPD. While impact strength and hardness properties showed promising result. Reuse of ' Fiber Reinforced Polymer ' dust can be improved by the present invention. (author)

Study of the Auger line shape of polyethylene and diamond

Energy Technology Data Exchange (ETDEWEB)

Dayan, M; Pepper, S V

1984-03-01

The KVV Auger electron line shapes of carbon in polyethylene and diamond have been studied. The spectra were obtained in derivative form by electron beam excitation. They were treated by background subtraction, integration and deconvolution to produce the intrinsic Auger line shape. Electron energy loss spectra provided the response function in the deconvolution procedure. The line shape from polyethylene is compared with spectra from linear alkanes and with a previous spectrum of Kelber et al. Both spectra are compared with the self-convolution of their full valence band densities of states and of their p-projected densities. The experimental spectra could not be understood in terms of existing theories. This is so even when correlation effects are qualitatively taken into account according to the theories of Cini and Sawatzky and Lenselink.

Relationship between bacterial density and chemical composition of ...

African Journals Online (AJOL)

TUOYO

Key words: Bacterial density, chemical composition, oxidation pond, sewage, tropics. INTRODUCTION ... pond for about two weeks during which algae, bacteria and other organisms act ..... Chloride can serve as nutrient for micro- organisms ...

A directional entrapment modification on the polyethylene surface by the amphiphilic modifier of stearyl-alcohol poly(ethylene oxide) ether

Science.gov (United States)

Lu, Qiang; Chen, Yi; Huang, Juexin; Huang, Jian; Wang, Xiaolin; Yao, Jiaying

2018-05-01

A novel entrapment modification method involving directional implantation of the amphiphilic modifier of stearyl-alcohol poly(ethylene oxide) ether (AEO) into the high-density polyethylene (HDPE) surface is proposed. This modification technique allows the AEO modifier to be able to spontaneously attain and subsequently penetrate into the swollen HDPE surface with its hydrophobic stearyl segment, while its hydrophilic poly(ethylene oxide) (PEO) segment spontaneously points to water. The AEO modifier with a HLB number below 8.7 was proved appropriate for the directional entrapment, Nevertheless, AEOs with larger HLB numbers were also effective modifiers in the presence of salt additives. In addition, a larger and hydrophobic micelle, induced respectively by the AEO concentration above 1.3 × 10-2 mol/L and the entrapping temperature above the cloud point of AEO, could lead to a sharp contact angle decline of the modified surface. Finally, a hydrophilic HDPE surface with the modifier coverage of 38.9% was reached by the directional entrapment method, which is far larger than that of 19.2% by the traditional entrapment method.

The effect of crystallization pressure on macromolecular structure, phase evolution, and fracture resistance of nano-calcium carbonate-reinforced high density polyethylene

International Nuclear Information System (INIS)

Yuan, Q.; Yang, Y.; Chen, J.; Ramuni, V.; Misra, R.D.K.; Bertrand, K.J.

2010-01-01

We describe here phase evolution and structural changes that are induced when high density polyethylene (HDPE) containing dispersion of nano-calcium carbonate is isothermally crystallized in the pressure range of 0.1-100 MPa. To delineate and separate the effects of applied crystallization pressure from nanoparticle effects, a relative comparison is made between neat HDPE and HDPE containing nano-calcium carbonate under similar experimental conditions. X-ray diffraction studies point toward the evolution of monoclinic phase at high crystallization pressure together with the commonly observed orthorhombic phase of HDPE. Furthermore, the nucleation of monoclinic phase is promoted by nanoparticles even at low crystallization pressure. The equilibrium melting point is insignificantly influenced on the addition of nanoparticle, such that the crystallization pressure has no obvious effect. The strong thermodynamic interaction between nano-calcium carbonate and HDPE is supported by the shift in glass transition temperature and changes in the modification of absorption bands of HDPE in Fourier transform infrared (FTIR) spectrum. Furthermore, the reinforcement of HDPE with nano-calcium carbonate increases impact strength and alters the micromechanism from crazing-tearing in polyethylene to fibrillated fracture in polymer nanocomposite, such that the fibrillation increases with crystallization pressure.

Investigation of photo-biodegradation of starch-filled polyethylene films under the environment conditions of Tehran

International Nuclear Information System (INIS)

Naeimian, F.; Khoylou, F.; Sheikh, N.; Akhavan, A.; Hassanpour, S.; Sohrabpour, M.

2006-01-01

In this work biodegradable polymers have been formulated for packaging purposes and with a view to reduce the environmental accumulation of plastic waste. Degradation of the polymers under the specific weathering conditions of Tehran was studied. In this work low-density polyethylene was formulated with two wheat starch concentrations, maleic anhydride, glycerol as well as a pro-oxidant system of oleic acid, benzoyl peroxide and ferric stearate. The formulated master batches were mixed by using a laboratory two-roll mill at 190 d ig C prepared master batches were mixed with the commercial low-density polyethylene to prepare compounds 1 and 2 containing 1.2 and 6.4 percents wheat starch. The low-density polyethylene control films as well as the formulated compounds were compression moulded in a hot press at 130 d ig C films were subjected to three general conditions of atmospheric exposure, buried in soil and combined conditions of soil burial/ atmospheric exposure. The three environmental conditions impact upon the formulated and control films were investigated through tensile strength, elongation-at-break, carbonyl index, water absorption, weight loss as well as SEM analysis. The microbial investigation was followed by growing the Penicillium Asymmetrica, which had the main population in microbial flora of the soil, on formulated and control films. The studies revealed that the incorporation of this pro-oxidant system with the addition of 6.4% wheat starch enhance the degradation rate of commercial low-density polyethylene films to a significant degree

Promising Poly(ε-caprolactone Composite Reinforced with Weft-Knitted Polyester for Small-Diameter Vascular Graft Application

Directory of Open Access Journals (Sweden)

Fu-Jun Wang

2014-01-01

Full Text Available The present study was designed to improve the mechanical performance of a small-diameter vascular prosthesis made from a flexible membrane of poly(ε-caprolactone (PCL. PCL reinforcement was achieved by embedding a tubular fabric knitted from polyethylene terephthalate (PET yarns within the freeze-dried composite structure. The knitting density of PET fabric influenced the mechanical properties of the new vascular graft. Results showed that the composite prototype has good mechanical properties, water permeability, elastic recovery, and suture retention strength. Increases in loop density increased compressive strength and suture retention strength and decreased elastic recovery. The new composite prototype vascular graft has promising potential applications in clinics because of its excellent mechanical properties.

Viscoelastic behaviour and fracture toughness of linear-low-density polyethylene reinforced with synthetic boehmite alumina nanoparticles

Directory of Open Access Journals (Sweden)

D. Pedrazzoli

2013-08-01

Full Text Available Aim of the present study is to investigate how synthetic boehmite alumina (BA nanoparticles modify the viscoleastic and fracture behaviour of linear low-density polyethylene. Nanocomposites containing up to 8 wt% of untreated and octyl silane-functionalized BA nanoparticles, were prepared by melt compounding and hot pressing. The BA nanoparticles were finely and unformly dispersed within the matrix according to scanning electron microscopy inspection. The results of quasi-static tensile tests indicated that nanoparticles can provide a remarkable stiffening effect at a rather low filler content. Short term creep tests showed that creep stability was significatively improved by nanofiller incorporation. Concurrently, both storage and loss moduli were enhanced in all nanocomposites, showing better result for surface treated nanoparticles. The plane-stress fracture toughness, evaluated by the essential work of fracture approach, manifested a dramatic increase (up to 64% with the BA content, with no significant differences among the various types of BA nanoparticles.

Interactions of polyethylene glycols with water studied by measurements of density and sound velocity

International Nuclear Information System (INIS)

Ayranci, Erol; Sahin, Melike

2008-01-01

Densities and sound velocities of ethylene glycol (EG) and polyethylene glycols (PEGs) of molecular weight 200, 300, 400, 550, 600, 1000, 1450, 3350, 8000, and 10,000 at (288.15, 298.15, and 308.15) K were measured with high precision vibrating tube densimeter and sound velocity measuring device. They were used to evaluate apparent molar volumes, V o , and apparent molar isentropic compressibilities, K ΦS . Infinite dilution values of these parameters, V o 0 , and K ΦS 0 , were obtained from their plot as a function of molality. The variations of V o 0 , and K ΦS 0 , with the number of repeating units in PEGs and with temperature were examined. Comparison of the experimentally obtained data was made with the available literature data and also with some values predicted according to group additivity approach. The results were interpreted in terms of hydration and conformational effects of PEGs in water. A correlation was also examined between V o 0 or K ΦS 0 values of PEGs in water and equilibrium moisture contents of PEGs as well as the water vapor permeabilities (WVP) of edible films containing PEGs

Influence of non-thermal plasma forming gases on improvement of surface properties of low density polyethylene (LDPE)

Energy Technology Data Exchange (ETDEWEB)

Pandiyaraj, K. Navaneetha, E-mail: dr.knpr@gmail.com [Surface Engineering Laboratory, Department of Physics, Sri Shakthi Institute of Engineering and Technology, L and T by pass, Chinniyam Palayam (post), Coimbatore 641062 (India); Deshmukh, R.R. [Department of Physics, Institute of Chemical Technology, Matunga, Mumbai 400 019 (India); Ruzybayev, Inci; Shah, S. Ismat [Department of Physics and Astronomy, Department of Materials Science and Engineering, University of Delaware, 208 Dupont Hall, Newark, NJ (United States); Su, Pi-Guey [Department of Chemistry, Chinese Culture University, Taipei 111, Taiwan (China); Halleluyah, Jr. mercy; Halim, Ahmad Sukari [School of Medical Sciences, Health Campus Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan (Malaysia)

2014-07-01

Owing to the superior physico-chemical properties, the low density polyethylene (LDPE) has been widely used in the various industrial applications; especially in biomedical field for artificial organs, medical devices and disposable clinical apparatus. However, the poor anticoagulation property is one of the main drawbacks of the LDPE due to its poor surface properties. Therefore, in this paper we present the effect of plasma forming gases such as argon (Ar), oxygen (O{sub 2}), air and argon-oxygen (Ar + O{sub 2}) mixture on improvement of the surfaces properties of LDPE film using direct current (dc) excited glow discharge plasma. Contact angle with evaluation of surface energy, X-ray photo electron spectroscopy (XPS), atomic force microscopy (AFM) techniques were used to examine the change in surface properties such as hydrophilicity, chemical composition and surface topography, respectively. Furthermore, the hydrophobic recovery of the plasma treated LDPE was analyzed using ageing effect under different storage condition i.e. in air and water. The adhesive strength of the LDPE films was determined using T-peel test. In vitro tests were used to examine the blood compatibility of the surface modified LDPE films. It has been found that the hydrophilicity of the various plasma treated LDPE films was improved significantly due to the formation of oxygen containing polar groups such as OH, COO, C-O, C=O as confirmed by contact angle and XPS analysis. AFM revealed the changes in surface topography of plasma processed films. The gas mixture Ar + O{sub 2} plasma influenced the remarkable improvement on the surface properties of a LDPE film compared with other gaseous plasmas. These physiochemical changes induced by the plasma on the surface facilitate to improve the adhesive strength and blood compatibility.

Influence of non-thermal plasma forming gases on improvement of surface properties of low density polyethylene (LDPE)

International Nuclear Information System (INIS)

Pandiyaraj, K. Navaneetha; Deshmukh, R.R.; Ruzybayev, Inci; Shah, S. Ismat; Su, Pi-Guey; Halleluyah, Jr. mercy; Halim, Ahmad Sukari

2014-01-01

Owing to the superior physico-chemical properties, the low density polyethylene (LDPE) has been widely used in the various industrial applications; especially in biomedical field for artificial organs, medical devices and disposable clinical apparatus. However, the poor anticoagulation property is one of the main drawbacks of the LDPE due to its poor surface properties. Therefore, in this paper we present the effect of plasma forming gases such as argon (Ar), oxygen (O 2 ), air and argon-oxygen (Ar + O 2 ) mixture on improvement of the surfaces properties of LDPE film using direct current (dc) excited glow discharge plasma. Contact angle with evaluation of surface energy, X-ray photo electron spectroscopy (XPS), atomic force microscopy (AFM) techniques were used to examine the change in surface properties such as hydrophilicity, chemical composition and surface topography, respectively. Furthermore, the hydrophobic recovery of the plasma treated LDPE was analyzed using ageing effect under different storage condition i.e. in air and water. The adhesive strength of the LDPE films was determined using T-peel test. In vitro tests were used to examine the blood compatibility of the surface modified LDPE films. It has been found that the hydrophilicity of the various plasma treated LDPE films was improved significantly due to the formation of oxygen containing polar groups such as OH, COO, C-O, C=O as confirmed by contact angle and XPS analysis. AFM revealed the changes in surface topography of plasma processed films. The gas mixture Ar + O 2 plasma influenced the remarkable improvement on the surface properties of a LDPE film compared with other gaseous plasmas. These physiochemical changes induced by the plasma on the surface facilitate to improve the adhesive strength and blood compatibility.

Molecular level computational studies of polyethylene and polyacrylonitrile composites containing single walled carbon nanotubes: effect of carboxylic acid functionalization on nanotube-polymer interfacial properties

Directory of Open Access Journals (Sweden)

Shayesteh eHaghighatpanah

2014-09-01

Full Text Available Molecular dynamics and molecular mechanics methods have been used to investigate additive-polymer interfacial properties in single walled carbon nanotube – polyethylene and single walled carbon nanotube – polyacrylonitrile composites. Properties such as the interfacial shear stress and bonding energy are similar for the two composites. In contrast, functionalizing the single walled carbon nanotubes with carboxylic acid groups leads to an increase in these properties, with a larger increase for the polar polyacrylonitrile composite. Increasing the percentage of carbon atoms that were functionalized from 1% to 5% also leads to an increase in the interfacial properties. In addition, the interfacial properties depend on the location of the functional groups on the single walled carbon nanotube wall.

Method to measure composition modifications in polyethylene terephthalate during ion beam irradiation

Science.gov (United States)

Abdesselam, M.; Stoquert, J. P.; Chami, S.; Djebara, M.; Chami, A. C.; Siad, M.

2009-01-01

Matter losses of polyethylene terephthalate (PET, Mylar) films induced by 1600 keV deuteron beams have been investigated in situ simultaneously by nuclear reaction analysis (NRA), deuteron forward elastic scattering (DFES) and hydrogen elastic recoil detection (HERD) in the fluence range from 1 × 10 14 to 9 × 10 16 cm -2. Volatile degradation products escape from the polymeric film, mostly as hydrogen-, oxygen- and carbon-containing molecules. Appropriate experimental conditions for observing the composition and thickness changes during irradiation are determined. 16O(d,p 0) 17O, 16O(d,p 1) 17O and 12C(d,p 0) 13C nuclear reactions were used to monitor the oxygen and carbon content as a function of deuteron fluence. Hydrogen release was determined simultaneously by H(d,d)H DFES and H(d,H)d HERD. Comparisons between NRA, DFES and HERD measurements show that the polymer carbonizes at high fluences because most of the oxygen and hydrogen depletion has already occured below a fluence of 3 × 10 16 cm -2. Release curves for each element are determined. Experimental results are consistent with the bulk molecular recombination (BMR) model.

Extraction of CdS pigment from waste polyethylene

NARCIS (Netherlands)

Wanrooij, P.H.P.; Agarwal, U.S.; Meuldijk, J.; Kasteren, van J.M.N.; Lemstra, P.J.

2006-01-01

Cadmium sulfide has often been used as a pigment in plastics such as high-density polyethylene (HDPE). Removal of CdS after the useful life of plastics is desired since it poses an environmental hazard in the waste phase of these plastics. In this study, a process is investigated to convert the

Cross-linked compared with historical polyethylene in THA: an 8-year clinical study.

Science.gov (United States)

Geerdink, Carel H; Grimm, Bernd; Vencken, Wendy; Heyligers, Ide C; Tonino, Alphons J

2009-04-01

Wear particle-induced osteolysis is a major cause of aseptic loosening in THA. Increasing wear resistance of polyethylene (PE) occurs by increasing the cross-link density and early reports document low wear rates with such implants. To confirm longer-term reductions in wear we compared cross-linked polyethylene (irradiation in nitrogen, annealing) with historical polyethylene (irradiation in air) in a prospective, randomized clinical study involving 48 patients who underwent THAs with a minimum followup of 7 years (mean, 8 years; range, 7-9 years). The insert material was the only variable. The Harris hip score, radiographic signs of osteolysis, and polyethylene wear were recorded annually. Twenty-three historical and 17 moderately cross-linked polyethylene inserts were analyzed (five patients died, three were lost to followup). At 8 years, the wear rate was lower for cross-linked polyethylene (0.088 +/- 0.03 mm/year) than for the historical polyethylene (0.142 +/- 0.07 mm/year). This reduction (38%) did not diminish with time (33% at 5 years). Acetabular cyst formation was less frequent (39% versus 12%), affected fewer DeLee and Charnley zones (17% versus 4%), and was less severe for the cross-linked polyethylene. The only revision was for an aseptically loose cup in the historical polyethylene group. Moderately cross-linked polyethylene maintained its wear advantage with time and produced less osteolysis, showing no signs of aging at mid-term followup. Level I, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Improved accuracy of cortical bone mineralization measured by polychromatic microcomputed tomography using a novel high mineral density composite calibration phantom

International Nuclear Information System (INIS)

Deuerling, Justin M.; Rudy, David J.; Niebur, Glen L.; Roeder, Ryan K.

2010-01-01

Purpose: Microcomputed tomography (micro-CT) is increasingly used as a nondestructive alternative to ashing for measuring bone mineral content. Phantoms are utilized to calibrate the measured x-ray attenuation to discrete levels of mineral density, typically including levels up to 1000 mg HA/cm 3 , which encompasses levels of bone mineral density (BMD) observed in trabecular bone. However, levels of BMD observed in cortical bone and levels of tissue mineral density (TMD) in both cortical and trabecular bone typically exceed 1000 mg HA/cm 3 , requiring extrapolation of the calibration regression, which may result in error. Therefore, the objectives of this study were to investigate (1) the relationship between x-ray attenuation and an expanded range of hydroxyapatite (HA) density in a less attenuating polymer matrix and (2) the effects of the calibration on the accuracy of subsequent measurements of mineralization in human cortical bone specimens. Methods: A novel HA-polymer composite phantom was prepared comprising a less attenuating polymer phase (polyethylene) and an expanded range of HA density (0-1860 mg HA/cm 3 ) inclusive of characteristic levels of BMD in cortical bone or TMD in cortical and trabecular bone. The BMD and TMD of cortical bone specimens measured using the new HA-polymer calibration phantom were compared to measurements using a conventional HA-polymer phantom comprising 0-800 mg HA/cm 3 and the corresponding ash density measurements on the same specimens. Results: The HA-polymer composite phantom exhibited a nonlinear relationship between x-ray attenuation and HA density, rather than the linear relationship typically employed a priori, and obviated the need for extrapolation, when calibrating the measured x-ray attenuation to high levels of mineral density. The BMD and TMD of cortical bone specimens measured using the conventional phantom was significantly lower than the measured ash density by 19% (p<0.001, ANCOVA) and 33% (p<0.05, Tukey's HSD

Thermally stimulated current of electron beam irradiation cross-linked polyethylene, (3)

International Nuclear Information System (INIS)

Aihara, Mitsugu; Aida, Fumio; Shiono, Takeo

1984-01-01

In the past, electron-beam irradiation was for the most part applied to rather thin insulation electric cables. Considering application to thick insulation, high voltage power cables (6.6 kV or more), the authors experimented on the charge accumulation and crystallizing properties of polyethylene due to irradiation, using three differently crystallizing samples, high and low density polyethylenes (HDPE and LDPE) and straight chain low density polyethylene (LLDPE), and have obtained some findings. Those are summarized as follows. (1) The crystallizing properties (crystallinity, the size of spherulite, etc.) of polyethylene varied according to the cooling condition, and affected the thermally stimulated current (TSC). (2) In HDPE and LDPE, the behaviour of crystallization differed. In HDPE, fine crystals decreased, and spherulites significantly grew in slow cooling, but in LDPE, the generation of fine crystals and the growth of spherulites simultaneously progressed. (3) The TSC peak area for HDPE was scarcely affected by slow cooling, but that for LDPE greatly increased. (4) The TSC of irradiated polyethylene showed peaks corresponding to the melting temperatures of fine crystals and spherulites when collecting voltage Vc was lowered. (5) The above facts suggest that fine crystals and spherulites took part as charge trap sites, but the aspect of participation was different in HDPE and LDPE. (6) LLDPE has the properties of both HDPE and LDPE in view of the crystallinity, charge accumulation was small, and it was hard to be affected by cooling condition. Accordingly, it seemed to be an interesting material as the PE for irradiation. A differential scanning calorimeter and laser small angle scattering method were used for the analysis of the measured results of TSC. (Wakatsuki, Y.)

Influence of light energy density on heat generation during photoactivation of dental composites with different dentin and composite thickness

Directory of Open Access Journals (Sweden)

Ricardo Danil Guiraldo

2009-08-01

Full Text Available OBJECTIVE: The aim of this study was to determine the influence of different energy densities on the heat generated during photoactivation of Filtek Z250 (3M/ESPE and Z100 (3M/ESPE composite resins with different dentin and composite thickness. MATERIAL AND METHODS: The temperature increase was registered with a type-K thermocouple connected to a digital thermometer (Iopetherm 46. A chemically polymerized acrylic resin base was prepared to serve as a guide for the thermocouple and as a support for 0.5-, 1.0-, and 1.5-mm-thick bovine dentin discs. Circular elastomer molds (1.0 mm-height x 3.0-mm diameter or 2.0-mm height x 3.0-mm diameter were adapted on the acrylic resin base to standardize the composite resin thickness. A conventional halogen light-curing unit (XL 2500, 3M/ESPE was used with light intensity of 700 mW/cm². Energy density was calculated by the light intensity applied during a certain time with values of 28 J/cm² for Z100 and 14 J/cm² for Filtek Z250. The temperature change data were subjected to three-way ANOVA and Tukey's test at 5% level. RESULTS: The higher energy density (Z100 promoted greater temperature increase (p<0.05 than the lower energy density (Filtek Z250. For both composites and all composite thicknesses, the lowest dentin thickness (0.5 mm yielded significantly higher (p<0.05 temperature increase than the other two dentin thicknesses. The 1-mm-thick composite resin layer yielded significantly higher (p<0.05 temperature changes for both composites and all dentin thicknesses. CONCLUSIONS: Temperature increase was influenced by higher energy density and dentin/composite thickness.

Recycling polyethylene terephthalate wastes as short fibers in Strain-Hardening Cementitious Composites (SHCC).

Science.gov (United States)

Lin, Xiuyi; Yu, Jing; Li, Hedong; Lam, Jeffery Y K; Shih, Kaimin; Sham, Ivan M L; Leung, Christopher K Y

2018-05-26

As an important portion of the total plastic waste bulk but lack of reuse and recycling, the enormous amounts of polyethylene terephthalate (PET) solid wastes have led to serious environmental issues. This study explores the feasibility of recycling PET solid wastes as short fibers in Strain-Hardening Cementitious Composites (SHCCs), which exhibit strain-hardening and multiple cracking under tension, and therefore have clear advantages over conventional concrete for many construction applications. Based on micromechanical modeling, fiber dispersion and alkali resistance, the size of recycled PET fibers was first determined. Then the hydrophobic PET surface was treated with NaOH solution followed by a silane coupling agent to achieve the dual purpose of improving the fiber/matrix interfacial frictional bond (from 0.64 MPa to 0.80 MPa) and enhancing the alkali resistance for applications in alkaline cementitious environment. With surface treatment, recycling PET wastes as fibers in SHCCs is a promising approach to significantly reduce the material cost of SHCCs while disposing hazardous PET wastes in construction industry. Copyright © 2018 Elsevier B.V. All rights reserved.

Ultra strong polymer fibers : Ab initio calculations on polyethylene

NARCIS (Netherlands)

Hageman, J.C.L.; Groot, R.A. de; Meier, Robert J.

1998-01-01

The Car-Parrinello technique is used to study the electronic structure of orthorhombic polyethylene as well as the elastic modulus. The theoretical band structure and density of states are in very good agreement with experiments. The best experimentally realized elastic modulus is better than 86% of

Effect of Boron and Phosphate compounds on Thermal and Fire Properties of wood/HDPE composites

Science.gov (United States)

Turgay Akbulut; Nadir Ayrilmis; Turker Dundar; Ali Durmus; Robert H. White; Murat Teker

2011-01-01

Melting and non-isothermal crystallization behaviors, oxidative induction time, and fire performance of the injection-molded wood flour-high density polyethylene (HDPE) composites (WPCs) incorporated with different levels (4, 8, or 12 wt %) of boron compounds [borax/boric acid (BX/BA) (0.5:0.5 wt %), zinc borate (ZB)] and phosphorus compounds [mono- and di-ammonium...

Catalytic thermal decomposition of polyethylene determined by thermogravimetric treatment

International Nuclear Information System (INIS)

Nisar, J.; Khan, M.S.; Khan, M.A.

2014-01-01

In this study low density polyethylene (LDPE) has been studied by thermogravimetric analysis (TGA) using commercially available oxides as catalysts. TGA experiments were used to evaluate the activity of different catalysts on low density polyethylene (LDPE) degradation and to study the effect in terms of type and amount of catalyst used. All the catalysts used improved the pyrolysis of LDPE. The reaction rates were found to increase with increase in amount of catalyst. Among the catalysts used, alumina acidic active catalyst performed better at all four fractions. Moreover, alumina acidic active reduced weight loss temperature better than others tested catalysts. The effect of alumina neutral catalyst on the pyrolysis of LDPE is less pronounced due to its small surface area and pore size. The effect of these catalysts showed that surface area, number of acidic sites and pore size were found as the key factors for the energy efficient degradation of polymers. (author)

Thermal Stress Effect on Density Changes of Hemp Hurds Composites

Science.gov (United States)

Schwarzova, Ivana; Cigasova, Julia; Stevulova, Nadezda

2016-12-01

The aim of this article is to study the behavior of prepared biocomposites based on hemp hurds as a filling agent in composite system. In addition to the filler and water, an alternative binder, called MgO-cement was used. For this objective were prepared three types of samples; samples based on untreated hemp hurds as a referential material and samples based on chemically (with NaOH solution) and physically (by ultrasonic procedure) treated hemp hurds. The thermal stress effect on bulk density changes of hemp hurds composites was monitored. Gradual increase in temperature led to composites density reduction of 30-40 %. This process is connected with mass loss of the adsorbed moisture and physically bound water and also with degradation of organic compounds present in hemp hurds aggregates such as pectin, hemicelluloses and cellulose. Therefore the changes in the chemical composition of treated hemp hurds in comparison to original sample and its thermal decomposition were also studied.

Thermal Stress Effect on Density Changes of Hemp Hurds Composites

Directory of Open Access Journals (Sweden)

Schwarzova Ivana

2016-12-01

Full Text Available The aim of this article is to study the behavior of prepared biocomposites based on hemp hurds as a filling agent in composite system. In addition to the filler and water, an alternative binder, called MgO-cement was used. For this objective were prepared three types of samples; samples based on untreated hemp hurds as a referential material and samples based on chemically (with NaOH solution and physically (by ultrasonic procedure treated hemp hurds. The thermal stress effect on bulk density changes of hemp hurds composites was monitored. Gradual increase in temperature led to composites density reduction of 30-40 %. This process is connected with mass loss of the adsorbed moisture and physically bound water and also with degradation of organic compounds present in hemp hurds aggregates such as pectin, hemicelluloses and cellulose. Therefore the changes in the chemical composition of treated hemp hurds in comparison to original sample and its thermal decomposition were also studied.

Influence of the irradiation conditions on the effect of radiation on polyethylene

Directory of Open Access Journals (Sweden)

BOJANA SECEROV

2004-12-01

Full Text Available Two types of polyethylene, low density (LDPE and high density (HDPE, as well as low density polyethylene containing an antioxidant were subjected to g-irradiation in the presence of air and in water. The irradiated polymers were studied using IR spectrophotometric analysis. The radiation induced oxidative degradation was followed through the formation of oxygen containing groups by the development of bands in the 1850–1650 cm-1 region and double bonds formation by the development of bands in the 1050–850 cm-1 region. The crosslinking efficiency was determined by measuring the gel content by extraction with xylene. The radiation induced changes in the molecular structure, evolution of oxygen containing species and formation, of vinyl double bonds as well as of the crosslinking efficiency are discussed in terms of the properties of the polymers in an electric field of low strength.

Multifunctional Carbon Nanotube/Polyethylene Complex Composites for Space Radiation Shielding, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Polyethylene (PE), due to its high hydrogen content relative to its weight, has been identified by NASA as a promising radiation shielding material against galactic...

Grafting functional antioxidants on highly crosslinked polyethylene

Science.gov (United States)

Al-Malaika, S.; Riasat, S.; Lewucha, C.

2016-05-01

The problem of interference of antioxidants, such as hindered phenols, with peroxide-initiated crosslinking of polyethylene was addressed through the use of functional (reactive) graftable antioxidants (g-AO). Reactive derivatives of hindered phenol and hindered amine antioxidants were synthesised, characterised and used to investigate their grafting reactions in high density polyethylene; both non-crosslinked (PE) and highly peroxide-crosslinked (PEXa). Assessment of the extent of in-situ grafting of the antioxidants, their retention after exhaustive solvent extraction in PE and PEXa, and the stabilising performance of the grafted antioxidants (g-AO) in the polymer were examined and benchmarked against conventionally stabilised crosslinked & non-crosslinked polyethylene. It was shown that the functional antioxidants graft to a high extent in PEXa, and that the level of interference of the g-AOs with the polymer crosslinking process was minimal compared to that of conventional antioxidants which bear the same antioxidant function. The much higher level of retention of the g-AOs in PEXa after exhaustive solvent extraction, compared to that of the corresponding conventional antioxidants, accounts for their superior long-term thermal stabilising performance under severe extractive conditions.

Landscape crop composition effects on cotton yield, Lygus hesperus densities and pesticide use.

Science.gov (United States)

Meisner, Matthew H; Zaviezo, Tania; Rosenheim, Jay A

2017-01-01

Landscape crop composition surrounding agricultural fields is known to affect the density of crop pests, but quantifying these effects, as well as measuring how they translate to changes in yield, is difficult. Using a large dataset consisting of 1498 records of commercial cotton production in California between 1997 and 2008, we explored the relationship between landscape composition and cotton yield, the density of Lygus hesperus (a key cotton pest) at field-level and within-field spatial scales and pesticide use. We found that the crop composition immediately adjacent to a cotton field was associated with substantial differences in cotton yield, L. hesperus density and pesticide use. Furthermore, crops that tended to be associated with increased L. hesperus density also tended to be associated with increased pesticide use and decreased cotton yield. Our results suggest a possible mechanism by which landscape composition can affect cotton yield: by increasing the density of pests which in turn damage cotton plants. Our quantification of how surrounding crops affect pest densities, and in turn yield, in cotton fields has significant impacts for cotton farmers, who can use this information to help optimize crop selection and ranch layout. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Preliminary evaluation of the immobilization of simulated evaporator concentrate waste in low density polyethylene by extrusion process

International Nuclear Information System (INIS)

Cota, Stela; Oliveira, Tania Valeria S. de; Senne Junior, Murillo; Pacheco, Graziella

2007-01-01

Simulated evaporator concentrate was prepared by pre-treating sodium borate with calcium hydroxide to produce an insoluble borate salt. The resultant solid waste was blended by extrusion with virgin low density polyethylene (LDPE) in the proportion of 30 wt%. Samples were prepared to evaluate homogeneity, mechanical strength and leaching behavior. The homogeneity of each sample individually and in consecutive samples was indirectly estimated by sectioning each sample in four pieces and submitting each piece to density determination (ASTM standard D-792). Mechanical strength was evaluated through determination of compressive strength (ASTM standard D-695), and the results were compared to the value for the pure polymer and with the limit established by CNEN standard NN-6.09 for cement waste products. Samples were also tested for leaching by accelerated leaching test (ASTM standard C1308). Results showed a good homogeneity. Standard deviations of the density measurements were less than 1% for a single sample and less than 6% considering 3 samples. Polymer compressive strength at yield point and at 5% and 10% strain have increased after the mixture with the simulated waste, indicating an increase on the material strength. Estimated compressive strength was above CNEN standard limit for cement waste products if 5% strain could be considered a reasonable limit to assure structural integrity of the material. Cumulated leaching fraction after 11 days of accelerated leaching test was found to be below 10%, and diffusion coefficient was estimated as 9.06 x 10 -10 cm 2 /s, with deviation of 8.3%. (author)

Preliminary evaluation of the immobilization of simulated evaporator concentrate waste in low density polyethylene by extrusion process

Energy Technology Data Exchange (ETDEWEB)

Cota, Stela; Oliveira, Tania Valeria S. de; Senne Junior, Murillo; Pacheco, Graziella [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)]. E-mail: sdsc@cdtn.br

2007-07-01

Simulated evaporator concentrate was prepared by pre-treating sodium borate with calcium hydroxide to produce an insoluble borate salt. The resultant solid waste was blended by extrusion with virgin low density polyethylene (LDPE) in the proportion of 30 wt%. Samples were prepared to evaluate homogeneity, mechanical strength and leaching behavior. The homogeneity of each sample individually and in consecutive samples was indirectly estimated by sectioning each sample in four pieces and submitting each piece to density determination (ASTM standard D-792). Mechanical strength was evaluated through determination of compressive strength (ASTM standard D-695), and the results were compared to the value for the pure polymer and with the limit established by CNEN standard NN-6.09 for cement waste products. Samples were also tested for leaching by accelerated leaching test (ASTM standard C1308). Results showed a good homogeneity. Standard deviations of the density measurements were less than 1% for a single sample and less than 6% considering 3 samples. Polymer compressive strength at yield point and at 5% and 10% strain have increased after the mixture with the simulated waste, indicating an increase on the material strength. Estimated compressive strength was above CNEN standard limit for cement waste products if 5% strain could be considered a reasonable limit to assure structural integrity of the material. Cumulated leaching fraction after 11 days of accelerated leaching test was found to be below 10%, and diffusion coefficient was estimated as 9.06 x 10{sup -10} cm{sup 2}/s, with deviation of 8.3%. (author)

A Comprehensive Study of Photorefractive Properties in Poly(ethylene glycol Dimethacrylate— Ionic Liquid Composites

Directory of Open Access Journals (Sweden)

Mostafa A. Ellabban

2016-12-01

Full Text Available A detailed investigation of the recording, as well as the readout of transmission gratings in composites of poly(ethylene glycol dimethacrylate (PEGDMA and ionic liquids is presented. Gratings with a period of about 5.8 micrometers were recorded using a two-wave mixing technique with a coherent laser beam of a 355-nm wavelength. A series of samples with grating thicknesses d 0 = 10 … 150 micrometers, each for two different exposure times, was prepared. The recording kinetics, as well as the post-exposure properties of the gratings were monitored by diffracting a low intensity probe beam at a wavelength of 633 nm for Bragg incidence. To obtain a complete characterization, two-beam coupling experiments were conducted to clarify the type and the strength of the recorded gratings. Finally, the diffraction efficiency was measured as a function of the readout angle at different post-exposure times. We found that, depending on the parameters, different grating types (pure phase and/or mixed are generated, and at elevated thicknesses, strong light-induced scattering develops. The measured angular dependence of the diffraction efficiency can be fitted using a five-wave coupling theory assuming an attenuation of the gratings along the thickness. For grating thicknesses larger than 85 microns, light-induced scattering becomes increasingly important. The latter is an obstacle for recording thicker holograms, as it destroys the recording interference pattern with increasing sample depth. The obtained results are valuable in particular when considering PEGDMA-ionic liquid composites in the synthesis of advanced polymer composites for applications, such as biomaterials, conductive polymers and holographic storage materials.

Improvement of the thermal and thermo-oxidative stability of high-density polyethylene by free radical trapping of rare earth compound

Energy Technology Data Exchange (ETDEWEB)

Ran, Shiya; Zhao, Li; Han, Ligang [Laboratory of Polymer Materials and Engineering, Ningbo Institute of Technology, ZhejiangUniversity, Ningbo, 315100 (China); MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Institute of Polymer Composites, Zhejiang University, Hangzhou, 310027 (China); Guo, Zhenghong, E-mail: guozhenghong@nit.zju.edu.cn [Laboratory of Polymer Materials and Engineering, Ningbo Institute of Technology, ZhejiangUniversity, Ningbo, 315100 (China); Fang, Zhengping [Laboratory of Polymer Materials and Engineering, Ningbo Institute of Technology, ZhejiangUniversity, Ningbo, 315100 (China); MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Institute of Polymer Composites, Zhejiang University, Hangzhou, 310027 (China)

2015-07-20

Highlights: • Polyethylene filled with ytterbium trifluoromethanesulfonate was prepared. • A low Yb loading improved thermal stability of PE obviously by radical trapping. • Yb(OTf){sub 3} is expected to be an efficient thermal stabilizer for the polymer. - Abstract: A kind of rare earth compound, ytterbium trifluoromethanesulfonate (Yb(OTf){sub 3}), was introduced into high-density polyethylene (HDPE) by melt compounding to investigate the effect of Yb(OTf){sub 3} on the thermal and thermo-oxidative stability of HDPE. The results of thermogravimetric (TG) and differential scanning calorimetry (DSC) showed that the addition of Yb(OTf){sub 3} made the thermal degradation temperatures dramatically increased, the oxidative induction time (OIT) extended, and the enthalpy (ΔH{sub d}) reduced. Very low Yb(OTf){sub 3} loading (0.5 wt%) in HDPE could increase the onset degradation temperature in air from 334 to 407 °C, delay the OIT from 11.0 to 24.3 min, and decrease the ΔH{sub d} from 61.0 to 13.0 J/g remarkably. Electron spin resonance spectra (ESR), thermogravimetric analysis coupled to Fourier transform infrared spectroscopy (TGA-FTIR), rheological investigation and pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) indicated that the free radicals-trapping ability of Yb(OTf){sub 3} was responsible for the improved thermal and thermo-oxidative stability.