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Sample records for acrylonitrile butadiene styrene

  1. Characterisation of recycled acrylonitrile-butadiene-styrene and high-impact polystyrene from waste computer equipment in Brazil.

    Science.gov (United States)

    Hirayama, Denise; Saron, Clodoaldo

    2015-06-01

    Polymeric materials constitute a considerable fraction of waste computer equipment and polymers acrylonitrile-butadiene-styrene and high-impact polystyrene are the main thermoplastic polymeric components found in waste computer equipment. Identification, separation and characterisation of additives present in acrylonitrile-butadiene-styrene and high-impact polystyrene are fundamental procedures to mechanical recycling of these polymers. The aim of this study was to evaluate the methods for identification of acrylonitrile-butadiene-styrene and high-impact polystyrene from waste computer equipment in Brazil, as well as their potential for mechanical recycling. The imprecise utilisation of symbols for identification of the polymers and the presence of additives containing toxic elements in determinate computer devices are some of the difficulties found for recycling of acrylonitrile-butadiene-styrene and high-impact polystyrene from waste computer equipment. However, the considerable performance of mechanical properties of the recycled acrylonitrile-butadiene-styrene and high-impact polystyrene when compared with the virgin materials confirms the potential for mechanical recycling of these polymers.

  2. Preparing cellulose nanocrystal/acrylonitrile-butadiene-styrene nanocomposites using the master-batch method.

    Science.gov (United States)

    Ma, Libo; Zhang, Yang; Meng, Yujie; Anusonti-Inthra, Phuriwat; Wang, Siqun

    2015-07-10

    The master-batch method provides a simple way to apply cellulose nanocrystal (CNC) as reinforcement in a hydrophobic matrix. The two-stage process includes making high-CNC content (70 wt%) master batch pellets, then mixing acrylonitrile-butadiene-styrene (ABS) and maleic anhydride grafted polyethylene with the master batch pellets to prepare the ABS/CNC nanocomposite in extruder. SEM image indicates that self-assembled CNC nanosheets disperse evenly throughout the polymer matrix. The improved mechanical properties shown in tensile and DMA tests reveal that the CNC combines well with the ABS. TGA results show that the thermal degradation temperature of CNC in the master batch increases because of the protection of the ABS coating. This approach not only improves the dispersion ability and the thermal stability of CNC, but it is also applicable to use with other hydrophobic thermoplastics in industrial scale production. PMID:25857992

  3. Structures and Properties Characterization of Acrylonitrile-butadiene-styrene/Organo-palygorskite Clay Composites

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhe; CHANG Ying; XU Jian; WU Zhancui; MA Hengchang; LEI Ziqiang

    2012-01-01

    Palygorskite (PGS) and vinyl tris-(2-methoxyethoxy) silane (KH-172) modified palygorskite (OPGS) were used to prepare acrylonitrile-butadiene-styrene (ABS)/clay composites.Thermal stability of the composites was evaluated by using thermogravimetric analysis (TGA).The morphology of the fractured surface and the degree of dispersion of the clay in the ABS matrix were observed by scanning electron microscopy (SEM).X-ray diffraction (XRD) analysis results showed the variation of the crystal structure.Measurements of the tensile properties of the ABS/clay composites proved that the ABS/OPGS composited material represented the most excellent tensile property,because of good compatibility and dispersion of ABS with OPGS.

  4. Flame Retardant Effects of Nano-Clinoptilolite on AcrylonitrileButadiene-Styrene (ABS Nano-Composite

    Directory of Open Access Journals (Sweden)

    Aboulfazl Barati

    2012-01-01

    Full Text Available In recent years, intumescent technology has found a place in polymer science as a method of providing flame retardance to polymeric materials. On heating, fire-retardant intumescent material restricts the action of the heat flux or flame. The proposed mechanism is based on charred layer acting as physical barrier, which slows down heat and mass transfer between the gas and the condensed phases. In this paper, the flammability of intumescent fire-retardant acrylonitrile-butadiene-styrene (ABS matrix composites consisting of hydromagnesite (HMg as an acid source and blowing agent, pentaerythritol (PER as a carbonisation agent and natural zeolite (clinoptilolite rich, Kansar Shargh as a synergistic agent were examined. The flammability of composites was characterized by limiting oxygen index (LOI measurement and horizontal burning tests. A synergistic effect in flame retardancy was observed when natural zeolites were used in combination with HMg and PER.

  5. EFFECT OF AMPHIPHILIC POLY (STYRENE-B-ETHYLENE OXIDE) DIBLOCK COPOLYMER INTERCALATED LAYERED SILICATE AS FILLER ON ACRYLONITRILE-BUTADIENE-STYRENE RESIN

    Institute of Scientific and Technical Information of China (English)

    Guo Tianying; Zhang Jie; Hao Guangjie; Song Moudao; Zhang Banghua

    2003-01-01

    The diblock copolymers intercalated layered silicate was prepared via a melt dispersion technique. Then the effect of intercalated hybrid as filler on acrylonitrile- butadiene-styrene resin was characterized by X-ray diffraction, transmission electron microscopy, stress-strain measurements in elongation.

  6. 21 CFR 177.1030 - Acrylonitrile/butadiene/styrene/methyl methacrylate copolymer.

    Science.gov (United States)

    2010-04-01

    ... as determined by a method titled “Analysis of Cycopac Resin for Residual β-(2-Hydroxyethylmercapto... the range of 13.0 to 16.0 percent as determined by Micro-Kjeldahl analysis. (2) Residual acrylonitrile... a gas chromatographic method titled “Determination of Residual Acrylonitrile and Styrene...

  7. Crack initiation and propagation on the polymeric material ABS (Acrylonitrile Butadiene Styrene, under ultrasonic fatigue testing

    Directory of Open Access Journals (Sweden)

    G. M. Domínguez Almaraz

    2015-10-01

    Full Text Available Crack initiation and propagation have been investigated on the polymeric material ABS (Acrylonitrile Butadiene Styrene, under ultrasonic fatigue testing. Three controlled actions were implemented in order to carry out fatigue tests at very high frequency on this material of low thermal conductivity, they are: a The applying load was low to limit heat dissipation at the specimen neck section, b The dimensions of testing specimen were small (but fitting the resonance condition, in order to restraint the temperature gradient at the specimen narrow section, c Temperature at the specimen neck section was restrained by immersion in water or oil during ultrasonic fatigue testing. Experimental results are discussed on the basis of thermo-mechanical behaviour: the tail phenomenon at the initial stage of fatigue, initial shear yielding deformation, crazed development on the later stage, plastic strain on the fracture surface and the transition from low to high crack growth rate. In addition, a numerical analysis is developed to evaluate the J integral of energy dissipation and the stress intensity factor K, with the crack length

  8. Carbon nanotube buckypaper reinforced acrylonitrile-butadiene-styrene composites for electronic applications.

    Science.gov (United States)

    Díez-Pascual, Ana M; Gascón, David

    2013-11-27

    Novel acrylonitrile-butadiene-styrene (ABS) nanocomposites reinforced with pristine or functionalized single- or multiwalled carbon nanotube buckypaper (BP) sheets were manufactured via hot-compression and vacuum infiltration. Their morphology, thermal, mechanical, and electrical properties were comparatively investigated. Scanning electron microscopy and thermogravimetric analysis showed that the infiltration process leads to better BP impregnation than the hot-press technique. BPs made from functionalized or short nanotubes form compact networks that hamper the penetration of the matrix chains, whereas those composed of pristine tubes possess large pores that facilitate the polymer flow, resulting in composites with low degree of porosity and improved mechanical performance. Enhanced thermal and electrical properties are found for samples incorporating functionalized BPs since dense networks lead to more conductive pathways, and a stronger barrier effect to the diffusion of degradation products, thus better thermal stability. According to dynamic mechanical analysis these composites exhibit the highest glass transition temperatures, suggesting enhanced filler-matrix interactions as corroborated by the Raman spectra. The results presented herein demonstrate that the composite performance can be tailored by controlling the BP architecture and offer useful insights into the structure-property relationships of these materials to be used in electronic applications, particularly for EMI shielding and packaging of integrated circuits. PMID:24171494

  9. THERMAL DECOMPOSITION AND FLAMMABILITY OF ACRYLONITRILE-BUTADIENE-STYRENE/MULTI-WALLED CARBON NANOTUBES COMPOSITES

    Institute of Scientific and Technical Information of China (English)

    Li-fang Tong; Hai-yun Ma; Zheng-ping Fang

    2008-01-01

    Thermal and flammability properties of acrylonitrile-butadiene-styrene copolymer (ABS) with the addition of multi-walled carbon nanotubes (MWNTs) were studied. ABS/MWNTs composites were prepared via melt blending with the MWNTs content varied from 0.2% to 4.0% by mass. Thermogravimetry results showed that the addition of MWNTs accelerated the degradation of ABS during the whole process under air atmosphere, and both onset and maximum degradation temperature were lower than those of pure ABS. The destabilization effect of MWNTs on the thermal stability of the composites became unobvious under nitrogen, and the addition of MWNTs could improve the maximum degradation temperature. The heat release rate and time of ignition (tign) for the composites reduced greatly with the addition of MWNTs especially when the concentration of nanotubes was higher than 1.0%. The accumulation of carbon nanotubes with a network structure was observed and the char layer became thicker with increasing nanotubes concentration. Results from Raman spectra showed a higher degree of graphitization for the residues of ABS/MWNTs composites.

  10. Fabrication of Acrylonitrile-Butadiene-Styrene Nanostructures with Anodic Alumina Oxide Templates, Characterization and Biofilm Development Test for Staphylococcus epidermidis.

    Directory of Open Access Journals (Sweden)

    Camille Desrousseaux

    Full Text Available Medical devices can be contaminated by microbial biofilm which causes nosocomial infections. One of the strategies for the prevention of such microbial adhesion is to modify the biomaterials by creating micro or nanofeatures on their surface. This study aimed (1 to nanostructure acrylonitrile-butadiene-styrene (ABS, a polymer composing connectors in perfusion devices, using Anodic Alumina Oxide templates, and to control the reproducibility of this process; (2 to characterize the physico-chemical properties of the nanostructured surfaces such as wettability using captive-bubble contact angle measurement technique; (3 to test the impact of nanostructures on Staphylococcus epidermidis biofilm development. Fabrication of Anodic Alumina Oxide molds was realized by double anodization in oxalic acid. This process was reproducible. The obtained molds present hexagonally arranged 50 nm diameter pores, with a 100 nm interpore distance and a length of 100 nm. Acrylonitrile-butadiene-styrene nanostructures were successfully prepared using a polymer solution and two melt wetting methods. For all methods, the nanopicots were obtained but inside each sample their length was different. One method was selected essentially for industrial purposes and for better reproducibility results. The flat ABS surface presents a slightly hydrophilic character, which remains roughly unchanged after nanostructuration, the increasing apparent wettability observed in that case being explained by roughness effects. Also, the nanostructuration of the polymer surface does not induce any significant effect on Staphylococcus epidermidis adhesion.

  11. Fittings of unplasticized polyvinyl chloride (PVC-U), chlorinated polyvinyl chloride (PVC-C) or acrylonitrile/butadiene/styrene (ABS) with plain sockets for pipes under pressure - Dimensions of sockets - Metric series

    CERN Document Server

    International Organization for Standardization. Geneva

    1985-01-01

    Fittings of unplasticized polyvinyl chloride (PVC-U), chlorinated polyvinyl chloride (PVC-C) or acrylonitrile/butadiene/styrene (ABS) with plain sockets for pipes under pressure - Dimensions of sockets - Metric series

  12. The effects of electron beam irradiation on the thermal properties, fatigue life and natural weathering of styrene butadiene rubber/recycled acrylonitrile-butadiene rubber blends

    International Nuclear Information System (INIS)

    Research highlights: → Addition of TMPTA helps to align polymer chains through crosslinking. → Improvement in fatigue life of irradiated blends due to formation of irradiation-induced crosslinks. → Excessive crosslinking caused reduction of tensile properties of irradiated SBR/NBRr blends. -- Abstract: The effects of electron beam (EB) irradiation on the thermal properties, fatigue life and natural weathering of styrene butadiene rubber/recycled acrylonitrile-butadiene rubber (SBR/NBRr) blends were investigated. The SBR/NBRr blends were prepared at 95/5, 85/15, 75/25, 65/35, or 50/50 blend ratios with and without the presence of a 3 part per hundred rubber (phr) of polyfunctional monomer, trimethylolpropane triacrylate (TMPTA). Results indicate that the crystallisation temperature (Tc) observed in polymeric blends is due to the alignment of polymer chains forming a semi-crystalline phase. Addition of TMPTA helps to align polymer chains through crosslinking. More crosslinking occurred between polymer blends with the help of TMPTA, upon irradiation. The improvement in fatigue life can also be associated with the stabilisation of SBR/NBRr blends upon irradiation and irradiation-induced crosslinking, which was accomplished with relatively low radiation-induced oxidative degradation in the presence of TMPTA. The tensile properties of both blends decreased over the periods of environmental exposure due to the effect of polymer degradation. After 6 months, the irradiated SBR/NBRr blends could not retain better retention [mainly with 25, 35 or 50 phr of recycled acrylonitrile-butadiene rubber (NBRr) particles] due to the samples becoming brittle over the long period of outdoor exposure.

  13. Effect of reactive compatibilization on the morphology and physical properties of bisphenol-A-polycarbonate/acrylonitrile-butadiene-styrene blends

    Science.gov (United States)

    Wildes, Gregg Stephen

    1998-11-01

    An amine functional styrene-acrylonitrile (SAN-amine) polymer is proposed as a reactive compatibilizer for bisphenol-A-polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) blends. This polymer is miscible with the styrene/acrylonitrile (SAN) copolymer matrix of ABS materials, and the pendant secondary amine groups react with PC at the carbonate linkage to form a SAN-g-PC copolymer. The graft copolymer molecules reside at the PC/ABS interface and provide improved morphological stability at elevated temperatures by suppressing phase coalescence. The synthesis of this reactive compatibilizer and its reaction with carbonate moieties is described. Characterization of this reaction was done by NMR and GPC using model secondary amine and carbonate containing compounds. A technique was developed for the quantitative measurement of the kinetics of dispersed phase particle coalescence in these blends; the morphology was examined using TEM. While uncompatibilized PC/SAN blends showed an increase in particle size from approximately 1 mum to 2 mum (depending on PC viscosity) in less than five minutes at 270sp°C; compatibilized blends containing as little as 1% SAN-amine exhibited no change in morphology after 20 minutes. The effects of dispersed phase concentration, viscosity ratio and interfacial compatibilization using the SAN-amine compatibilizer on the process induced morphology of PC/SAN blends were also examined. Dispersed phase particle size increased significantly with SAN concentration and, although the morphology of uncompatibilized PC/SAN blends mixed in a Brabender mixer, single and twin screw extruders were quite similar, the twin screw extruder produced significantly finer morphologies in blends containing SAN-amine. The average particle size for blends compatibilized with the SAN-amine polymer was approximately half that of uncompatibilized blends and was relatively independent of viscosity ratio and dispersed phase composition. The fracture of thin (3.18 mm

  14. Analysis of acrylonitrile, 1,3-butadiene, and related compounds in acrylonitrile-butadiene-styrene copolymers for kitchen utensils and children's toys by headspace gas chromatography/mass spectrometry.

    Science.gov (United States)

    Ohno, Hiroyuki; Kawamura, Yoko

    2010-01-01

    A headspace gas chromatography/mass spectrometry method was developed for the simultaneous determination of the residual levels of acrylonitrile (AN), 1,3-butadiene (1,3-BD), and their related compounds containing propionitrile (PN) and 4-vinyl-1-cyclohexene (4-VC) in acrylonitrile-butadiene-styrene (ABS) copolymers for kitchen utensils and children's toys. A sample was cut into small pieces, then N,N-dimethylacetamide and an internal standard were added in a sealed headspace vial. The vial was incubated for 1 h at 90 degrees C and the headspace gas was analyzed by gas chromatography/mass spectrometry. The recovery rates of the analytes were 93.3-101.8% and the coefficients of variation were 0.3-6.5%. In ABS copolymers, the levels were 0.3-50.4 microg/g for AN, ND-4.5 microg/g for PN, 0.06-1.58 microg/g for 1,3-BD, and 1.1-295 microg/g for 4-VC. The highest level was found for 4-VC, which is a dimer of 1,3-BD, and the next highest was for AN, which is one of the monomers of the ABS copolymer. Furthermore, the method was also applied to acrylonitrile-styrene (AS) copolymers and polystyrenes (PS) for kitchen utensils, and nitrile-butadiene rubber (NBR) gloves. In AS copolymers, AN and PN were detected at 16.8-54.5 and 0.8-6.9 microg/g, respectively. On the other hand, the levels in PS and NBR samples were all low. PMID:21313827

  15. Isolation of the {epsilon}-caprolactam denitrifying bacteria from a wastewater treatment system manufactured with acrylonitrile-butadiene-styrene resin

    Energy Technology Data Exchange (ETDEWEB)

    Wang, C.-C. [Department of Environmental Engineering, Hungkuang University, Shalu, Taichung 433, Taiwan (China)]. E-mail: chunchin@sunrise.hk.edu.tw; Lee, C.-M. [Department of Environmental Engineering, National Chung Hsing University, Taichung 402, Taiwan (China)

    2007-06-25

    {epsilon}-Caprolactam has high COD and toxicity, so its discharge to natural water and soil systems may lead to an adverse environmental effect on water quality, endangering public health and welfare. This investigation attempts to isolate {epsilon}-caprolactam denitrifying bacteria from a wastewater treatment system manufactured with acrylonitrile-butadiene-styrene (ABS) resin. The goal is to elucidate the effectiveness of isolated pure strain and ABS mixed strains in treating {epsilon}-caprolactam from synthetic wastewater. The results reveal that Paracoccus versutus MDC-3 was isolated from the wastewater treatment system manufactured with ABS resin. The ABS mixed strains and P. versutus MDC-3 can consume up to 1539 mg/l {epsilon}-caprolactam to denitrify from synthetic wastewater. Complete {epsilon}-caprolactam removal depended on the supply of sufficient electron acceptors (nitrate). Strain P. versutus MDC-3, Hyphomicrobium sp. HM, Methylosinus pucelana and Magnetospirillum sp. CC-26 are related closely, according to the phylogenetic analyses of 16S rDNA sequences.

  16. Isolation of the epsilon-caprolactam denitrifying bacteria from a wastewater treatment system manufactured with acrylonitrile-butadiene-styrene resin.

    Science.gov (United States)

    Wang, Chun-Chin; Lee, Chi-Mei

    2007-06-25

    epsilon-Caprolactam has high COD and toxicity, so its discharge to natural water and soil systems may lead to an adverse environmental effect on water quality, endangering public health and welfare. This investigation attempts to isolate epsilon-caprolactam denitrifying bacteria from a wastewater treatment system manufactured with acrylonitrile-butadiene-styrene (ABS) resin. The goal is to elucidate the effectiveness of isolated pure strain and ABS mixed strains in treating epsilon-caprolactam from synthetic wastewater. The results reveal that Paracoccus versutus MDC-3 was isolated from the wastewater treatment system manufactured with ABS resin. The ABS mixed strains and P. versutus MDC-3 can consume up to 1539mg/l epsilon-caprolactam to denitrify from synthetic wastewater. Complete epsilon-caprolactam removal depended on the supply of sufficient electron acceptors (nitrate). Strain P. versutus MDC-3, Hyphomicrobium sp. HM, Methylosinus pucelana and Magnetospirillum sp. CC-26 are related closely, according to the phylogenetic analyses of 16S rDNA sequences. PMID:17161908

  17. Reclamation of post-consumer plastics for development of polycarbonate and acrylonitrile butadiene styrene based nanocomposites with nanoclay

    Science.gov (United States)

    Zicans, Janis; Meri, Remo Merijs; Ivanova, Tatjana; Berzina, Rita; Saldabola, Ruuta; Maksimov, Robert

    2016-05-01

    Suitability of recycled acrylonitrile-butadiene-styrene (R-ABS) and recycled polycarbonate (R-PC) for the development of polymer matrix nanocomposites with organically modified nanoclay (OMMT) is evaluated in comparison to virgin polymers (V-ABS and V-PC) based systems. The influence of OMMT content on the structure as well as calorimetric, mechanical and thermal properties of virgin and recycled polymers containing systems is revealed. Increase in stiffness and strength of virgin and recycled polymers based systems is observed along with rising nanoclay content. However, it is observed that reinforcing efficiency of clays on the R-ABS containing systems is reduced to certain extent in comparison to those, based on virgin polymers. It is shown, that in the presence of OMMT approximation of glass transition temperatures of both polymeric components is observed, which can testify about certain improvement of compatibility between PC and ABS. Increment of the modulus of elasticity and yield strength of the nanocomposites is associated with anisodiametric shape of OMMT, as well as with intercalation of polymer within the interlaminar space of the clay nanoparticles. It is also demonstrated that addition of nanoclay improves thermogravimetric behavior of the investigated compositions. Consequently, it is suggested that nanoclays can be used as promising functional additives and replace halogenated flame-retardants, without reducing mechanical properties of the composites.

  18. FINITE ELEMENT SIMULATION FOR YIELD STRESS OF HARD POLY(VINYL CHLORIDE)/ACRYLONITRILE-BUTADIENE-STYRENE BLENDS AT DIFFERENT CROSSHEAD SPEEDS

    Institute of Scientific and Technical Information of China (English)

    Pei-hua Du; Jie Yu; Peng-fei Lin; Yi-hu Song; Qiang Zneng

    2011-01-01

    Hard poly(vinyl chloride) (PVC)/acrylonitrile-butadiene-styrene (ABS) blends were prepared using injectionmolding and influence of crosshead speed on mechanical properties was examined.Based on morphology parameters obtained from transmission electron microscopy photography and the material parameters from true stress-strain curves of neat PVC and ABS,yield stresses of the blends at different crosshead speeds were simulated employing a two-dimensional nine-particle model based on the finite element analysis (FEA).The FEA results were compared with the experimental yielding stress and the good agreement validated the simulation approach.The FEA approach allowed establishing a yielding criterion related to local yielding of the interstitial matrix between ABS particles.

  19. Flame retardancy mechanisms of bisphenol A bis(diphenyl phosphate) in combination with zinc borate in bisphenol A polycarbonate/acrylonitrile-butadiene-styrene blends

    International Nuclear Information System (INIS)

    Bisphenol A polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) with and without bisphenol A bis(diphenyl phosphate) (BDP) and 5 wt.% zinc borate (Znb) were investigated. The pyrolysis was studied by thermogravimetry (TG), TG-FTIR and NMR, the fire behaviour with a cone calorimeter applying different heat fluxes, LOI and UL 94. Fire residues were examined with NMR. BDP affects the decomposition of PC/ABS and acts as a flame retardant in the gas and condensed phases. The addition of Znb results in an additional hydrolysis of PC. The fire behaviour is similar to PC/ABS, aside from a slightly increased LOI and a reduced peak heat release rate, both caused by borates improving the barrier properties of the char. In PC/ABS + BDP + Znb, the addition of Znb yields a borate network and amorphous phosphates. Znb also reacts with BDP to form alpha-zinc phosphate and borophosphates that suppress the original flame retardancy mechanisms of BDP. The inorganic-organic residue formed provides more effective flame retardancy, in particular at low irradiation in the cone calorimeter, and a clear synergy in LOI, whereas for more developed fires BDP + Znb become less effective than BDP in PC/ABS with respect to the total heat evolved.

  20. Co-recycling of acrylonitrile-butadiene-styrene waste plastic and nonmetal particles from waste printed circuit boards to manufacture reproduction composites.

    Science.gov (United States)

    Sun, Zhixing; Shen, Zhigang; Zhang, Xiaojing; Ma, Shulin

    2015-01-01

    This study investigated the feasibility of using acrylonitrile-butadiene-styrene (ABS) waste plastic and nonmetal particles from waste printed circuit boards (WPCB) to manufacture reproduction composites (RC), with the aim of co-recycling these two waste resources. The composites were prepared in a twin-crew extruder and investigated by means of mechanical testing, in situ flexural observation, thermogravimatric analysis, and dimensional stability evaluation. The results showed that the presence of nonmetal particles significantly improved the mechanical properties and the physical performance of the RC. A loading of 30 wt% nonmetal particles could achieve a flexural strength of 72.6 MPa, a flexural modulus of 3.57 GPa, and an impact strength of 15.5 kJ/m2. Moreover, it was found that the application of maleic anhydride-grafted ABS as compatilizer could effectively promote the interfacial adhesion between the ABS plastic and the nonmetal particles. This research provides a novel method to reuse waste ABS and WPCB nonmetals for manufacturing high value-added product, which represents a promising way for waste recycling and resolving the environmental problem.

  1. Butadiene-acrylonitrile elastomers as PVC modifiers

    OpenAIRE

    M. Rojek; J. Stabik

    2007-01-01

    Purpose: The purpose of the paper is to present the results of research programme on influence of acrylonitrile-butadiene copolymers on plasticized polyvinylchloride compounds used as window gasket material.Design/methodology/approach: Short review concerning application of modified plasticized PVC compounds as gasket material was presented. In experimental part two types of acrylonitrile-butadiene copolymers were used as elastomeric plasticizers for PVC. Formulations with fifteen dif...

  2. Laser transmission welding of Acrylonitrile-Butadiene-Styrene (ABS) using a tailored high power diode-laser optical fiber coupled system

    Science.gov (United States)

    Rodríguez-Vidal, E.; Quintana, I.; Etxarri, J.; Otaduy, D.; González, F.; Moreno, F.

    2012-06-01

    Laser transmission welding (LTW) of polymers is a direct bonding technique which is already used in different industrial applications sectors such as automobile, microfluidic, electronic and biomedicine. This technique offers several advantages over conventional methods, especially when a local deposition of energy and minimum thermal distortions are required. In LTW one of the polymeric materials needs to be transparent to the laser wavelength and the second part needs to be designed to be absorbed in IR spectrum. This report presents a study of laser weldability of ABS (acrylonitrile/butadiene/styrene) filled with two different concentrations of carbon nanotubes (0.01% and 0.05% CNTs). These additives are used as infrared absorbing components in the laser welding process, affecting the thermal and optical properties of the material and, hence, the final quality of the weld seam. A tailored laser system has been designed to obtain high quality weld seams with widths between 0.4 and 1.0mm. It consists of two diode laser bars (50W per bar) coupled into an optical fiber using a non-imaging solution: equalization of the beam quality factor (M2) in the slow and fast axes by a pair of micro step-mirrors. The beam quality factor has been analyzed at different laser powers with the aim to guarantee a coupling efficiency to the multimode optical fiber. The power scaling is carried out by means of multiplexing polarization technique. The analysis of energy balance and beam quality is performed in two linked steps: first by means ray tracing simulations (ZEMAX®) and second, by validation. Quality of the weld seams is analyzed in terms of the process parameters (welding speed, laser power and clamping pressure) by visual and optical microscope inspections. The optimum laser power range for three different welding speeds is determinate meanwhile the clamping pressure is held constant. Additionally, the corresponding mechanical shear tests were carried out to analyze the

  3. Modification of PVC compounds with butadiene-acrylonitrile elastomers

    OpenAIRE

    J. Stabik; M. Rojek

    2006-01-01

    Purpose: The purpose of the paper is to present the research programme on influence of acrylonitrile-butadiene copolymers on properties of plasticized polyvinylchloride as window gaskets material.Design/methodology/approach: Short literature review concerning application of modified PVC as gasket material was presented. In experimental part two types of acrylonitrile-butadiene copolymers were used as elastomeric plasticizers. Compounds with fifteen different levels of modifiers content (up to...

  4. Blends of Styrene-Butadiene-Styrene Triblock Copolymer with Random Styrene-Maleic Anhydride Copolymers

    NARCIS (Netherlands)

    Piccini, Maria Teresa; Ruggeri, Giacomo; Passaglia, Elisa; Picchioni, Francesco; Aglietto, Mauro

    2002-01-01

    Blends of styrene-butadiene-styrene triblock copolymer (SBS) with random styrene-maleic anhydride copolymers (PS-co-MA), having different MA content, were prepared in a Brabender Plastigraph mixer. The presence of polystyrene (PS) blocks in the SBS copolymer and the high styrene content (93 and 86 w

  5. Biocompatibility of epoxidized styrene-butadiene-styrene block copolymer membrane

    International Nuclear Information System (INIS)

    Styrene-butadiene-styrene block copolymer (SBS) membrane was prepared by solution casting method and then was epoxidized with peroxyformic acid generated in situ to yield the epoxidized styrene-butadiene-styrene block copolymer membrane (ESBS). The structure and properties of ESBS were characterized with infrared spectroscopy, Universal Testing Machine, differential scanning calorimetry (DSC), and thermogravimetry analysis (TGA). The performances of contact angle, water content, protein adsorption, and water vapor transmission rate on ESBS membrane were determined. After epoxidation, the hydrophilicity of the membrane increased. The water vapor transmission rate of ESBS membrane is similar to human skin. The biocompatibility of ESBS membrane was evaluated with the cell culture of fibroblasts on the membrane. It revealed that the cells not only remained viable but also proliferated on the surface of the various ESBS membranes and the population doubling time for fibroblast culture decreased.

  6. Modification of PVC compounds with butadiene-acrylonitrile elastomers

    Directory of Open Access Journals (Sweden)

    J. Stabik

    2006-04-01

    Full Text Available Purpose: The purpose of the paper is to present the research programme on influence of acrylonitrile-butadiene copolymers on properties of plasticized polyvinylchloride as window gaskets material.Design/methodology/approach: Short literature review concerning application of modified PVC as gasket material was presented. In experimental part two types of acrylonitrile-butadiene copolymers were used as elastomeric plasticizers. Compounds with fifteen different levels of modifiers content (up to 25% by weight were prepared and tested. Additionally three commercial compounds were tested as reference formulations. The following test were performed: Shore hardness, short-term and long-term elastic recovery, tensile strength, elongation at break and migration of plasticizers from gasket material to unplasticized PVC.Findings: Application of acrylonitrile-butadiene copolymers as PVC modifier enhanced many properties essential for window gasket materials such as long-term and short term elastic recovery, tensile strength and elongation at break. At the same time addition of these elastomers did not change migration of other plasticizers contained in gasket material. Obtained results indicated that among tested compounds best properties as gasket material exhibited plasticized PVC with 23% of acrylonitrile-butadiene copolymer Chemigum P83. Reference commercial compounds exhibited worse performance properties than compounds with this acrylonitrile-butadiene copolymer. Practical implications: Research programme allowed to elaborate plasticized PVC compounds modified with acrylonitrile-butadiene copolymer that can be industrially applied for PVC window gaskets.Originality/value: Obtained results are of scientific and practical value. Research programme allowed to investigate the influence of elastomeric modifiers on plasticized PVC properties. Research results are also of practical importance.

  7. Comparison of sodium naphthenate and air-ionization corona discharge as surface treatments for the ethylene-tetrafluoroethylene polymer (ETFE) to improve adhesion between ETFE and acrylonitrile-butadiene-styrene polymer (ABS) in the presence of a cyanoacrylate adhesive (CAA)

    Science.gov (United States)

    Lucía Johanning-Solís, Ana; Stradi-Granados, Benito A.

    2014-09-01

    This study compares two ethylene-tetrafluoroethylene (ETFE) surface activation treatments, namely chemical attack with a solution of sodium naphthenate and plasma erosion via air-ionization corona discharge in order to improve the adhesive properties of the ETFE. An experimental design was prepared for both treatments in order to assess the effect of the treatment characteristics on the tensile load needed to break the bond between the ETFE and the acrylonitrile-butadiene-styrene polymer (ABS) formed with a cyanoacrylate adhesive (CAA) applied between them. The reason for the selection of this problem is that both polymers are frequently used in the biomedical industry for their properties, and they need to be joined firmly in biomedical devices, and the cyanoacrylate adhesive is the adhesive traditionally used for fluoropolymers, in this case the ETFE, and the same CAA has also shown good adhesion with ABS. However, the strength of the bond for the triplet ETFE-CAA-ABS has not been reported and the improvement of the strength of the bond with surface treatments is not found in scholarly journals for modern medical devices such as stents and snares. Both treatments were compared based on the aforementioned design of experiments. The case where ETFE receives no surface treatment serves as the reference. The results indicated that the three factors evaluated (initial drying of the material, temperature of the chemical bath, and immersion time), and their interactions have no significant effect over the tensile load at failure (tensile strength) of the adhesive bond being evaluated. For the air-ionization corona discharge treatment, two factors were evaluated: discharge exposition time and air pressure. The results obtained from this experimental design indicate that there is no significant difference between the levels of the factors evaluated. These results were unexpected as the ranges used were representative of the maximum ranges permissible in manufacturing

  8. Blends of Styrene-Butadiene-Styrene Triblock Copolymer with Random Styrene-Maleic Anhydride Copolymers

    OpenAIRE

    Piccini, Maria Teresa; Ruggeri, Giacomo; Passaglia, Elisa; Picchioni, Francesco; Aglietto, Mauro

    2002-01-01

    Blends of styrene-butadiene-styrene triblock copolymer (SBS) with random styrene-maleic anhydride copolymers (PS-co-MA), having different MA content, were prepared in a Brabender Plastigraph mixer. The presence of polystyrene (PS) blocks in the SBS copolymer and the high styrene content (93 and 86 wt.-%, respectively) in the two kinds of used PS-co-MA samples afforded a good compatibility between the PS phases of the two polymers. On the other hand, the presence of polar anhydride groups allo...

  9. Recycling of Chrome Tanned Leather Dust in Acrylonitrile Butadiene Rubber

    Science.gov (United States)

    El-Sabbagh, Salwa H.; Mohamed, Ola A.

    2010-06-01

    Concerns on environmental waste problem caused by chrome tanned leather wastes in huge amount have caused an increasing interest in developing this wastes in many composite formation. This leather dust was used as filler in acrylonitrile butadiene rubber (NBR) before treatment and after treatment with ammonia solution and sod. formate. Different formulations of NBR/ leather dust (untreated-treated with ammonia solution—treated with sod. formate) composites are prepared. The formed composite exhibit a considerable improvement in some of their properties such as rheometric characteristics especially with composites loaded with treated leather dust. Tensile strength, modulus at 100% elongation, hardness and youngs modulus were improved then by further loading start to be steady or decrease. Cross linking density in toluene were increased by incorporation of leather dust treated or untreated resulting in decreases in equilibrium swelling. Distinct increase in the ageing coefficient of both treated and untreated leather with drop in NBR vulcanizates without leather dust. Addition of leather dust treated or untreated exhibit better thermal stability.

  10. Chrome-tanned leather shavings as a filler of butadiene-acrylonitrile rubber.

    Science.gov (United States)

    Przepiórkowska, A; Chrońska, K; Zaborski, M

    2007-03-01

    The noxious wastes from the tanning industry such as chrome-tanned leather shavings were used as the only filler of rubber mixes containing carboxylated butadiene-acrylonitrile rubber (XNBR) or butadiene-acrylonitrile rubber (NBR), and a dispersing agent Limanol PEV (Schill & Seilacher). The best form addition of leather powder to the rubber mixes is mixed the waste protein with zinc oxide. The leather powder added to the rubber mixes improves the mechanical properties: tensile strength (T(s)), elongation at break (epsilon(b)) and increase the cross-linking density of carboxylated XNBR and NBR rubber mixes. Satisfactory results of these studies are presented in this work. PMID:16942836

  11. Carbon nanotubes as reinforcement of styrene-butadiene rubber

    International Nuclear Information System (INIS)

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

  12. STUDY ON THE EPOXY RESIN TOUGHENED BY HYDROXY-TERMINATED BUTADIENE-ACRYLONITRILE COPOLYMER

    Institute of Scientific and Technical Information of China (English)

    HAN Xiaozu; LI Shaoying; ZHANG Qingyu

    1990-01-01

    Toughened epoxy resin with excellent properties was obtained by adding organic acid anhydride curing agent and hydroxy-terminated butadiene-acrylonitrile copolymer (HTBN), which is cheaper than CTBN. The anhydride reacts with both epoxy groups on epoxy resin and hydroxyl groups on HTBN. As a result the soft long chains of HTBN and the rigid chain of epoxy resin form one network, giving the resin toughness. Two-phase structure of the toughened resin was observed by SEM and TEM.

  13. Durability of styrene-butadiene latex modified concrete

    Energy Technology Data Exchange (ETDEWEB)

    Shaker, F.A.; El-Dieb, A.S.; Reda, M.M. [Ain Shams Univ., Cairo (Egypt). Dept. of Structural Engineering

    1997-05-01

    The durability of reinforced concrete structures represents a major concern to many investigators. The use of latex modified concrete (LMC) in construction has urged researchers to review and investigate its different properties. This study is part of a comprehensive investigation carried on the use of polymers in concrete. The main objective of this study to investigate and evaluate the main durability aspects of Styrene-Butadiene latex modified concrete (LMC) compared to those of conventional concrete. Also, the main microstructural characteristics of LMC were studied using a Scanning Electron Microscope (SEM). The SEM investigation of the LMC showed major differences in its microstructure compared to that of the conventional concrete. The LMC proved to be superior in its durability compared to the durability of conventional concrete especially its water tightness (measured by water penetration, absorption, and sorptivity tests), abrasion, corrosion, and sulphate resistance.

  14. Evaluation of tri-steps modified styrene-butadiene-styrene block copolymer membrane for wound dressing

    International Nuclear Information System (INIS)

    Tri-steps modified styrene-butadiene-styrene block copolymer (SBS) membrane was prepared with epoxidation, ring opening reaction with maleated ionomer and layer-by-layer assembled polyelectrolyte technique. The tri-steps modified SBS membrane was characterized by infrared spectroscopy and X-ray photoelectron spectroscope (XPS). The structures of the modified SBS membranes were identified with methylene blue and azocarmine G. The content of amino group on the surface of the modified membrane was calculated from uptake of an acid dye. The values of the contact angle, water absorption, water vapor transmission rate and the adsorption of fibronectin on the membranes were determined. To evaluate the biocompatibility of the tri-steps modified SBS membrane, the cytotoxicity, antibacterial and growth profile of the cell culture of 3T3 fibroblasts on the membrane were evaluated. The bactericidal activity was found on the modified SBS. From the cell culture of 3T3 fibroblasts on the membrane, it revealed that the cells not only remained viable but also proliferated on the surface of the tri-steps modified SBS membranes. As the membranes are sterile semipermeable with bactericidal activity and transparent allowing wound checks, they can be considered for shallow wound with low exudates. - Highlights: ► Styrene-butadiene-styrene block copolymer (SBS) was modified with tri-steps. ► The tri-steps are epoxidation, ring opening reaction and layer-by-layer assembly. ► Modified SBS membrane for wound dressing is evaluated. ► Membranes are sterile semipermeable with bactericidal activity and transparent. ► Membranes can be considered for shallow wound with low exudates.

  15. Electromechanical responses of poly(3-thiopheneacetic acid/acrylonitrile-butadiene rubbers

    Directory of Open Access Journals (Sweden)

    2008-12-01

    Full Text Available Acrylonitrile-butadiene rubber (NBR and blends of poly(3-thiopheneacetic acid/ acrylonitrile-butadiene rubber, P3TAA/NBR, were fabricated, and the electrorheological properties, dielectric, and electrical conductivities were investigated . The electrorheological properties were determined under an oscillatory shear mode in a frequency range of 0.1 to 100 rad/s at various electric field strengths, from 0 to 2 kV/mm, at a fixed 27°C to observe the effects of acrylonitrile content (ACN in the rubber systems and the conductive particle concentration in the blends. For the pure rubber systems, the storage modulus response (ΔG′ is linearly dependent on its dielectric constant (ε′, and increases with the ACN content. For the NBR/P3TAA blends, the storage modulus response varies nonlinearly with the dielectric constant. The bending responses of the rubbers and the blends were investigated in a vertical cantilever fixture. For the pure rubber system, the bending angle and the dielectrophoresis force vary linearly with electric field strength. For the blend system, the bending angle and the dielectrophoresis force vary nonlinearly with electric field strength.

  16. Preparation of anionically polymerized butadiene-co-styrene copolymer-multiwalled carbon nanotubes nanocomposites

    Institute of Scientific and Technical Information of China (English)

    Zhong Guang; Wang, Jing Hua; Ling Xu

    2012-01-01

    Poly(butadiene-co-styrene) copolymer/multi-walled carbon nanotubes (SB-MWNTs) nanocomposites are prepared via terminating anionically synthesized living poly(butadiene-styryl)lithium with acyl chlorides on the MWNTs,which obtained from the carboxylation and acylation of the MWNTs.Results from the characterization of the SB-MWNTs nanocomposites,including its soluble in solvent,UV-vis and TEM of the dissolved samples,TGA and SEM of nanocomposites are presented and discussed respectively.MWNTs treated by SB can be easily distributed in the SBR (styrene-butadiene rubber) matrix.

  17. EFFECTS OF STYRENE-BUTADIENE-STYRENE ON STIFFNESS OF ASPHALT CONCRETE AT DIFFERENT TRAFFIC CONDITIONS

    Directory of Open Access Journals (Sweden)

    GHOLAMALI SHAFABAKHSH

    2016-04-01

    Full Text Available The previous studies have explored the effects of Styrene-Butadiene-Styrene (SBS as the most prevalent modifier for asphalt mixtures. The current study intends to compare stiffness modulus of control and SBS modified asphalt mixtures under different traffic loadings. To this end, resilient modulus tests were performed on both conventional and SBS modified specimens. Tests were conducted at 5, 25 and 40°C with loading times of 50, 100, 300, 600 and 1000 milliseconds and 4, 9 and 30 as ratio of rest periods (between loading pulses to loading times (R/L. Using these test parameters and haversine and square loading pulses that represent vertical stress distribution at different depths within an asphalt layer, a variety of traffic densities and vehicle speeds were simulated and their effects on stiffness of asphalt concrete were determined. Results indicated that SBS modification provide higher stiffness under haversine pulse with long loading time at 40°C, so that it was about 3 times of unmodified mixture stiffness. The effect of traffic density that represented by R/L was significant only in long loading time (1000 ms especially under haversine pulse.

  18. Radiation-induced crosslinking of poly(styrene-butadiene-styrene) block copolymers and their sulfonation

    Science.gov (United States)

    Lee, Sun-Young; Song, Ju-Myung; Sohn, Joon-Yong; Shul, Yong-Gun; Shin, Junhwa

    2013-12-01

    Several crosslinked poly(styrene-butadiene-styrene) (c-SBS) block copolymer films were prepared using a gamma ray or electron beam with various irradiation doses and the prepared c-SBS film was then subjected to sulfonation using a chlorosulfonic acid (CSA) solution to introduce a sulfonic acid group. To estimate the degree of crosslinking, the gel fractions and FT-IR spectra of the c-SBS films were used and the results indicate that the degree of crosslinking is increased with an increase in the radiation dose. The surface morphology and mechanical property of the c-SBS films were observed using SEM and UTM instruments, respectively. The sulfonated c-SBS films were investigated by measuring the ion exchange capacity (IEC) and by observing the cross-sectional distribution patterns of sulfonic acid group using an SEM-EDX instrument. The IEC and SEM-EDX studies indicate that the sulfonated c-SBS membranes can be successfully prepared through the radiation crosslinking of the SBS film and the subsequent sulfonation with a diluted CSA solution.

  19. Recycling cycle of materials applied to acrylonitrile-butadiene-styrene/policarbonate blends with styrene-butadiene-styrene copolymer addition

    Science.gov (United States)

    Cândido, L. H. A.; Ferreira, D. B.; Júnior, W. Kindlein; Demori, R.; Mauler, R. S.

    2014-05-01

    The scope of this research is the recycling of polymers from mobile phones hulls discarded and the performance evaluation when they are submitted to the Recycling Cycle of Materials (RCM). The studied material was the ABS/PC blend in a 70/30 proportion. Different compositions were evaluated adding virgin material, recycled material and using the copolymer SBS as impact modifier. In order to evaluate the properties of material's composition, the samples were characterized by TGA, FTIR, SEM, IZOD impact strength and tensile strength tests. At the first stage, the presented results suggest the composition containing 25% of recycled material and 5% of SBS combines good mechanical performance to the higher content of recycled material and lower content of impact modifier providing major benefits to recycling plans. Five cycles (RCM) were applied in the second stage; they evidenced a decrease trend considering the impact strength. At first and second cycle the impact strength was higher than reference material (ABS/PC blend) and from the fourth cycle it was lower. The superiority impact strength in the first and second cycles can be attributed to impact modifier effect. The thermal tests and the spectrometry didn't show the presence of degradation process in the material and the TGA curves demonstrated the process stability. The impact surface of each sample was observed at SEM. The microstructures are not homogeneous presenting voids and lamellar appearance, although the outer surface presents no defects, demonstrating good moldability. The present work aims to assess the life cycle of the material from the successive recycling processes.

  20. Synthesis And Properties Of Functional Ultra-High Molecular Weight Transparent Styrene-Butadiene Block Copolymer

    Institute of Scientific and Technical Information of China (English)

    GONG Guang-bi; ZHAO Xu-tao; WANG Gui-lun

    2004-01-01

    Functional ultra-high molecular weight transparent styrene-butadiene block copolymer possesses both high transparency and impact resistance and has excellent comprehensive properties prior to other transparent resins. In this paper we not only use anionic polymerization process which includes 1 time addition of initiator and 3 time addition of monomers, but also introduce functional coupling agent for the fist time to prepare mentioned functional block copolymer.The typical preparation process is described as the following: (a) Adding cyclohexane, styrene and initiator to the polymerizer, the polymerization is carried out at 50~75℃; (b) adding a mixture of styrene, butadiene and cyclohexane, the polymerization is carried out at 50~70℃ ;(c) adding a mixture of butadiene and cyclohexane, the polymerization is finished at 60~70℃ ;(d) adding coupling agent which is a substituted trimethoxysilane being expressed as N-silane, O-silane and being converted into a functional group (-NH, -OH) of mentioned block copolymer, coupling at 75~90℃ for 1 hr; (e) The amounts of coupling agent are about one sixth to one third of the initiator; (f) treating the prepared copolymer solution with some water and Carbon dioxide at 50~70℃ for 15 min.The copolymer is from three-arm to six-arm mono-modal radial block copolymer having 75~90%styrene, 10~25% butadiene and functional group of-NH or-OH. of the copolymer, Mw is from 30×104 to 120×104, Mw/Mn from 2.0 to 2.5, Izod notched impact strength 50~65 J/m,light transmission not less 87.5%, tensile strength not less 45 Mpa.The exploratory research shows that the mole ratio and feed rate of the random copolymerized styrene-butadiene, as well as the total ratio of styrene-butadiene have greater influence on the properties of the copolymer. The following model is established:Y=bo +∑3j=1 bjxj+∑3j=1bkjxkxj+∑3j=1bjjx2j (k<j)Where: Y is the light transmission, tensile strength, elongation, Izod notched impact

  1. Production and market analysis of styrene butadiene rubber%丁苯橡胶生产及市场分析

    Institute of Scientific and Technical Information of China (English)

    晓战东; 孙雅斌; 白延军; 苏波; 郭滨诗

    2013-01-01

    The paper summarizes the production and market of styrene butadiene rubber both at home and abroad,analyzes the domestic styrene butadiene rubber development trend,and puts forward some advices on the problems in the domestic styrene butadiene rubber industry.%综述了国内外丁苯橡胶的生产及市场情况,对国内丁苯橡胶的市场发展趋势进行了分析.此外,还对国内丁苯橡胶行业存在的不足提出了几点建议.

  2. Carboxyl-terminated butadiene-acrylonitrile-toughened epoxy/carboxyl-modified carbon nanotube nanocomposites: Thermal and mechanical properties

    OpenAIRE

    H. F. Xie; Wang, Y. T.; Wang, C. S.; H. Y. Yin; Wang, L.L.; R. S. Cheng

    2012-01-01

    Carboxyl-modified multi-walled carbon nanotubes (MWCNT–COOHs) as nanofillers were incorporated into diglycidyl ether of bisphenol A (DGEBA) toughened with carboxyl-terminated butadiene-acrylonitrile (CTBN). The carboxyl functional carbon nanotubes were characterized by Fourier-transform infrared spectroscopy and thermogravimetric analysis. Furthermore, cure kinetics, glass transition temperature (Tg), mechanical properties, thermal stability and morphology of DGEBA/CTBN/MWCNT–COOH...

  3. Morphology and Dynamic Mechanical Properties of Diglycidyl Ether of Bisphenol-A Toughened with Carboxyl-Terminated Butadiene-Acrylonitrile

    Science.gov (United States)

    Hong, S. D.; Chung, S. Y.; Fedors, R. F.; Moacanin, J.; Gupta, A.

    1984-01-01

    The fracture toughness of an incorporation of a carboxyl-terminated butadiene acrylonitrile (CTBN) elastomer in diglycidyl ether bisphenol A (DGEBA) resin was investigated. Measurements of dynamic mechanical properties, scanning electron microscopy and small-angle X-ray scattering were carried out to characterize the state of cure, morphology and particle size and size distribution of the neat resins and their graphite fiber reinforced composites.

  4. Gamma Radiation Shielding Properties of Styrene- Butadiene Rubber/Lead Oxide Composites

    International Nuclear Information System (INIS)

    Styrene-butadiene rubber/lead oxide composites were prepared as gamma-radiation shields. The composites were prepared with different concentrations of red lead oxide (Pb3O4). The assessment of the linear attenuation coefficient of the SBR/lead oxide composites for gamma -rays from 137Cs gamma -radiation point source was studied. The styrene-butadiene rubber/lead oxide composites can attain up to about 43% of the shielding capacity of pure lead. The incorporation of high concentrations of lead oxide and the effect of accumulative irradiation doses up to 3000 kGy on the physico-mechanical properties of the composites were studied. These led to hardening of the SBR rubber/lead oxide composites

  5. Thermal Stability and Flammability of Styrene-Butadiene Rubber-Based (SBR) Ceramifiable Composites

    OpenAIRE

    Rafał Anyszka; Dariusz M. Bieliński; Zbigniew Pędzich; Przemysław Rybiński; Mateusz Imiela; Mariusz Siciński; Magdalena Zarzecka-Napierała; Tomasz Gozdek; Paweł Rutkowski

    2016-01-01

    Ceramifiable styrene-butadiene (SBR)-based composites containing low-softening-point-temperature glassy frit promoting ceramification, precipitated silica, one of four thermally stable refractory fillers (halloysite, calcined kaolin, mica or wollastonite) and a sulfur-based curing system were prepared. Kinetics of vulcanization and basic mechanical properties were analyzed and added as Supplementary Materials. Combustibility of the composites was measured by means of cone calorimetry. Their t...

  6. Performance Analysis of Styrene Butadiene Rubber-Latex on Cement Concrete Mixes.

    OpenAIRE

    Er. Kapil Soni; Dr. Y. P Joshi

    2014-01-01

    To improve the performance of concrete, polymers are mixed with concrete. It has been observed that polymer-modified concrete (PMC) is more durable than conventional concrete due to superior strength and high durability. In this research, effect of Styrene-Butadiene Rubber (SBR) latex on compressive strength and flexural strength of concrete has been studied and also the optimum polymer (SBR-Latex) content for concrete is calculated. This research was carried out to establish t...

  7. MORPHOLOGY,INTERFACIAL INTERACTION AND PROPERTIES OF STYRENE-BUTADIENE RUBBER/MODIFIED HALLOYSITE NANOTUBE NANOCOMPOSITES

    Institute of Scientific and Technical Information of China (English)

    贾德民

    2009-01-01

    A natural nanotubular material,halloysite nanotubes(HNTs),was introduced to prepare styrene-butadiene rubber/modified halloysite nanotube(SBR/m-HNT) nanocomposites.Complex of resorcinol and hexamethylenetetramine (RH) was used as the interfacial modifier.The structure,morphology and mechanical properties of SBR/m-HNT nanocomposites,especially the interfacial interactions,were investigated.SEM and TEM observations showed that RH can not only facilitate the dispersion and orientation of HNTs in SBR matrix ...

  8. 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.

  9. Microstrueture and Properties of Fluoroelastomer/Butadiene-Acrylonitrile Rubber Interpenetrating Polymer Networks

    Institute of Scientific and Technical Information of China (English)

    CHEN Chunming; XIONG Chuanxi; YANG Jian; DONG Lijie

    2008-01-01

    Interpenetrating polymer networks(IPNs)based on fluoroelastomer/butadiene-acrylonitrile rubber(FKM/NBR)by molten blending at a high temperature and chemical cross-linking of two components were prepared.The influence of the two networks component on the mechanical properties and thermostabilities was studied.The experimental results show that the mechanical properties of the IPNs are superior to those of the individual FKM and NBR networks due to forming the case of interpenetrating and intercross-linking between the two networks,the mechanical properties and thermal resistance exhibit higher values when 80/20(w/w)FKM and NBR is blended and respectively cured simultaneously.The co-continuous morphology of the IPNs in the blends of 80/20(w/w)FKM/NBR is found by transmission electron microscopy(TEM),the differential scanning calorimetry(DSC)determination shows that the blends of 80/20(w/w)FKM/NBR have better compatibility,and the glass transition temperature of the elastomer is -21.5℃.

  10. The physical and degradation properties of starch-graft-acrylonitrile/carboxylated nitrile butadiene rubber latex films.

    Science.gov (United States)

    Misman, M A; Azura, A R; Hamid, Z A A

    2015-09-01

    Starch-graft-acrylonitrile (ANS) is compounded with carboxylated nitrile butadiene rubber (XNBR) latex. The control XNBR and the ANS/XNBR latex films were prepared through a coagulant dipping process. The films were subjected to ageing and soil burial procedures. For the biodegradation experiment, the surface of the film was assessed after the 2nd, 4th and 8th week of soil burial. The ANS, XNBR, and ANS/XNBR colloidal stability were determined with a Malvern Zetasizer. For the dipped latex films, the mechanical, morphological and thermal properties were analyzed. The addition of ANS into the XNBR latex increased the stability of the colloidal dispersions, decreased the latex film tensile strength, but increased the elongation at break due to the bipolar interaction of the ANS and XNBR particles. The ANS/XNBR latex films aged faster than the control films while the morphological analysis showed the existence of a starch crystal region and the formation of microbial colonies on the surfaces of the films. Based on the TGA-DTA curves, a higher ΔT was observed for the ANS/XNBR latex films signifying high thermal energy needed for the film to thermally degrade. PMID:26005134

  11. Mechanical property modification and morphology of poly(styrene-b-hydrogenated butadiene-b-styrene)/poly(hydrogenated butadiene) blends

    Energy Technology Data Exchange (ETDEWEB)

    Baetzold, J.P.; Gancarz, I.; Quan, X.; Koberstein, J.T. (Univ. of Connecticut, Storrs, CT (United States))

    1994-09-12

    The mechanical properties and morphology of a series of triblock copolymer blends with midblock associating homopolymers of varying molecular weight (Mw) have been characterized. The symmetric triblock copolymer studied contains polystyrene endblocks and midblocks of hydrogenated poly(1,2-butadiene) and is mixed with hydrogenated poly (1,2-butadiene) homopolymers of Mw both below and above that of the copolymer midblock. The rubbery plateau modulus determined by dynamic mechanical spectroscopy increases with increasing Mw of the homopolymer at fixed overall homopolymer content. At fixed Mw, the composition dependence of the plateau modulus is complex and shows unusually synergistic behavior. For high Mw homopolymers the plateau modulus increases initially upon homopolymer addition. Small angle neutron scattering and TEM are employed to determine the morphological changes. In all cases, the blends exhibit a lamellar microphase structure, with homopolymer macrophases apparent at high homopolymer contents. The apparent homopolymer solubility limits are found to be inversely related to the homopolymer Mw. The results indicate that the lamellar repeat distance decreases upon addition of the lowest Mw homopolymer and that the microdomains swell in blends containing homopolymers with Mw similar to that of the midblock sequence and are unchanged for high Mw homopolymers with negligible solubility. The results suggest that the interesting mechanical response of the blends can be explained by consideration of the changes in their entanglement structure resulting from confinement of the homopolymer chains within the highly constrained environment of the midblock lamellae.

  12. STUDY ON STYRENE-BUTADIENE BLOCK COPOLYMER FOR THE MODIFICATION OF TIRE TREAD

    Institute of Scientific and Technical Information of China (English)

    WANG Yan; CHEN Weijie; MU Ruifeng; WANG Yongwei; YU Fengnian; LIU Qing

    1996-01-01

    This paper mainly deals with the design and synthesis of a novel styrene-butadiene block copolymer. When this copolymer is used in the tread portion of tyres, it can improve wet skid resistance and reduce rolling resistance without sacrificing its general physicalmechanical properties. The visco-elastic curve of tire tread using the novel copolymer as its rubber portion was showed. Reactivity ratios for two monomers in the polymerizing system were calculated. The diagrams of differential, integral and finite difference calculi throughout the whole molecular chain were presented. The influence of the micro- and macro-structure of the copolymer chain on wet skid resistance and rolling resistance was discussed.

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

    OpenAIRE

    Yu, P.; He, H; Jiang, C; Wang, D; Jia, Y.; Zhou, L.; D. M. Jia

    2015-01-01

    In this study, lignin-novolac epoxy resin networks were fabricated in the styrene butadiene rubber (SBR) matrix by combination of latex compounding and melt mixing. Firstly, SBR/lignin compounds were co-coagulated by SBR latex and lignin aqueous solution. Then the novolac epoxy resin (F51) was added in the SBR/lignin compounds by melt compounding method. F51 was directly cured by lignin via the ring-opening reaction of epoxy groups of F51 and OH groups (or COOH groups) of lignin during the cu...

  14. Magnetic properties of barium ferrite dispersed within polystyrene-butadiene-styrene block copolymers.

    Science.gov (United States)

    Chipara, M; Skomski, R; Ali, N; Hui, D; Sellmyer, D J

    2009-06-01

    Magnetic properties of nanocomposite materials obtained by dispersing barium ferrite nanoparticles within polystyrene-butadiene-styrene block copolymer, in the temperature range, 300 to 500 K are reported. The temperature dependence of the magnetization at saturation, averaged uniaxial magnetocrystalline anisotropy, and coercive field of thick films are analyzed. A "matrix effect" was noticed within the glass transition range of the hard component (polystyrene) of the polymeric matrix. The reported modifications of the magnetic properties were assigned to the competition between the magnetic and mechanical reorientation of nanoparticles within the polymeric matrix. Such modifications were not observed in barium ferrite dispersed in cement. PMID:19504902

  15. Dielectric study of Poly(styrene- co -butadiene) Composites with Carbon Black, Silica, and Nanoclay

    KAUST Repository

    Vo, Loan T.

    2011-08-09

    Dielectric spectroscopy is used to measure polymer relaxation in styrene-butadiene rubber (SBR) composites. In addition to the bulk polymer relaxation, the SBR nanocomposites also exhibit a slower relaxation attributed to polymer relaxation at the polymer-nanoparticle interface. The glass transition temperature associated with the slower relaxation is used as a way to quantify the interaction strength between the polymer and the surface. Comparisons were made among composites containing nanoclay, silica, and carbon black. The interfacial relaxation glass transition temperature of SBR-clay nanocomposites is more than 80 °C higher than the SBR bulk glass transition temperature. An interfacial mode was also observed for SBR-silica nanocomposites, but the interfacial glass transition temperature of SBR-silica nanocomposite is somewhat lower than that of clay nanocomposites. An interfacial mode is also seen in the carbon black filled system, but the signal is too weak to analyze quantitatively. The interfacial polymer relaxation in SBR-clay nanocomposites is stronger compared to both SBR-carbon black and SBR-silica composites indicating a stronger interfacial interaction in the nanocomposites containing clay. These results are consistent with dynamic shear rheology and dynamic mechanical analysis measurements showing a more pronounced reinforcement for the clay nanocomposites. Comparisons were also made among clay nanocomposites using different SBRs of varying styrene concentration and architecture. The interfacial glass transition temperature of SBR-clay nanocomposites increases as the amount of styrene in SBR increases indicating that styrene interacts more strongly than butadiene with clay. © 2011 American Chemical Society.

  16. 21 CFR 177.1020 - Acrylonitrile/butadiene/sty-rene co-polymer.

    Science.gov (United States)

    2010-04-01

    ... acrylonitrile adduct as determined by a method titled “Analysis of Cycopac Resin for Residual β-(2... copolymer is in the range of 16 to 18.5 percent as determined by Micro-Kjeldahl analysis. (2) Residual... determined by a gas chromatographic method titled “Determination of Residual Acrylonitrile and...

  17. Performance Analysis of Styrene Butadiene Rubber-Latex on Cement Concrete Mixes.

    Directory of Open Access Journals (Sweden)

    Er. Kapil Soni

    2014-03-01

    Full Text Available To improve the performance of concrete, polymers are mixed with concrete. It has been observed that polymer-modified concrete (PMC is more durable than conventional concrete due to superior strength and high durability. In this research, effect of Styrene-Butadiene Rubber (SBR latex on compressive strength and flexural strength of concrete has been studied and also the optimum polymer (SBR-Latex content for concrete is calculated. This research was carried out to establish the effects of polymer addition on compressive and flexural strength using concrete with mix design of constant water-cement ratio at local ambient temperature. The mixes were prepared with Styrene-Butadiene Rubber (SBR latex -cement ratio of 0 %, 5%, 10%, 15% and 20%. Slump test was conducted on fresh concrete while compressive strength and flexural strength were determined at different age. A locally available Perma-Latex is used as SBR Latex. It has been observed that SBR latex has negative effect at early age while at 28 days, the addition of SBR latex in concrete results in enhancement of compressive strength and Flexural Strength. Based on the results of this study, latex modified concrete made using Perma-Latex may be recommended to be used with various types of concrete structures. However, for the mixes rich in cement, the dosage of SBR latex needs to be adjusted to maintain required workability of concrete.

  18. Modification of poly(styrene-block-butadiene-block-styrene) [SBS] with phosphorus containing fire retardants

    DEFF Research Database (Denmark)

    Chernyy, Sergey; Ullah, Saif; Jomaas, Grunde;

    2015-01-01

    of the Psingle bondH containing fire retardants to a double bonds of poly(butadiene) block of SBS were found, affording varied degree of the modification (0.2–21 mol%). Alternatively, a two-step procedure based on an epoxidation step followed by hydrolysis of the epoxides with phosphoric acid was developed......An elaborate survey of the chemical modification methods for endowing highly flammable SBS with increased fire resistant properties by means of chemical modification of the polymer backbone with phosphorus containing fire retardant species is presented. Optimal conditions for free radical addition...... application of the H3PO4 modified SBS as a fire retardant additive for bitumen material, in combination with synergetic melamine species, offered 25% better self-extinguishing properties of such formulation already at a low loading level of the fire retardant components (3.5 wt.%)....

  19. DYNAMIC MECHANICAL PROPERTIES OF STYRENE-BUTADIENE COMPOSITES REINFORCED BY DEFATTED SOY FLOUR AND CARBON BLACK CO-FILLER

    Science.gov (United States)

    Carboxylated styrene-butadiene (SB) composites reinforced by a mixture of defatted soy flour (DSF) and carbon black (CB) were investigated in terms of their dynamic mechanical properties. DSF is an abundant renewable commodity and has a lower cost than CB. DSF contains soy protein, soy carbohydrat...

  20. Regenerated thermosetting styrene-co-acrylonitrile sandwich composite panels reinforced by jute fibre: structures and properties

    Indian Academy of Sciences (India)

    Jinglong Li; Qin Peng; Anrong Zeng; Junlin Li; Xiaole Wu; Xiaofei Liu

    2016-02-01

    Jute fibres-reinforced sandwich regenerated composite panels were fabricated using industrial waste thermosetting styrene-co-acrylonitrile (SAN) foam scraps via compression moulding for the purpose of recycling waste SAN foam and obtaining high physical performance. The jute fibres were, respectively, treated by heat, sodium hydroxide (NaOH) solution (5.0 wt%), and N,N-dimethylacetamide (DMAc) in order to improve the mechanical properties of the composites. The structures and mechanical properties of the composites were studied. The SAN matrix got compact and some crystalline region formed in SAN matrix via compression moulding. The composite reinforced by DMAc-treated jute fibres performed optimum mechanical properties among the regenerated panels whose impact strength, flexural strength, and compressive strength were 19.9 kJ m−2, 41.7 MPa, and 61.0 MPa, respectively. Good interfacial bonding between DMAc-treated fibres and SAN matrix was verified by peel test and exhibited in SEM photographs. Besides, the water absorption of DMAc-treated fibres composite was lower than other SAN/jute fibre-reinforced sandwich composite panels.

  1. High-Energy-Density Poly(styrene-co-acrylonitrile) Thin Films

    Science.gov (United States)

    Wen, Fei; Xu, Zhuo; Xia, Weimin; Ye, Hongjun; Wei, Xiaoyong; Zhang, Zhicheng

    2013-12-01

    The dielectric response of poly(styrene-co-acrylonitrile) (PSAN) thin films fabricated by a solution casting process was investigated in this work. Linear dielectric behavior was obtained in PSAN films under an electric field at frequencies from 100 Hz to 1 MHz and temperature of -50°C to 100°C. The polymer films exhibited an intermediate dielectric permittivity of 4 and low dielectric loss (tan δ) of 0.027. Under 400 MV/m, the energy density of the PSAN films was 6.8 J/cm3, which is three times higher than that of biaxially oriented polypropylene (BOPP) (about 1.6 J/cm3). However, their charge-discharge efficiency (about 90%) was rather close to that of BOPP. The calculated effective dielectric permittivity of the PSAN films under high electric field was as high as 9, which may be attributed to the improved displacement of the cyanide groups (-CN) polarized at high electric fields. These high-performance features make PSAN attractive for high-energy-density capacitor applications.

  2. Quantitative characterization of the sequential mers distribution in styrene-butadiene copolymers by {sup 13} C; Caracterizacao quantitativa da distribuicao sequencial dos meros em copolimeros de estireno e butadieno por RMN de {sup 13} C

    Energy Technology Data Exchange (ETDEWEB)

    Canevarolo, Sebastiao [Sao Carlos Univ., SP (Brazil). Dept. de Engenharia de Materiais

    1996-06-01

    Various types and grades of styrene-butadiene co-polymers were analysed by {sup 13} C-NMR: random SBR, blocked SSBR (a styrene block is introduced in the random SBR chain) and SBS triblock copolymers. It was determined the styrene content (%), the styrene-butadiene mers distribution in terms of the S-B and B-S-B sequences content (characteristics of the random portions of the chain) and also the isomers content in the butadiene phase. (author)

  3. Microstructural analysis of carbon nanotubes produced from pyrolysis/combustion of styrene-butadiene rubber

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Joner O.; Zhuo, Chuanwei; Levendis, Yannis A. [Northeastern Univ., Boston, MA (United States). Coll. of Engineering. Dept. of Mechanical and Industrial Engineering; Tenorio, Jorge A.S. [University of Sao Paulo (USP), SP (Brazil). Polytechnic School. Dept. of Metallurgical and Materials Engineering

    2010-07-01

    Styrene-Butadiene-Rubber (SBR) is a synthetic rubber copolymer used to fabricate several products. This study aims to demonstrate the use of SBR as feedstock for carbon nanotubes (CNTs) growth, and therefore to establish a novel process for destination for wastes produced from SBR. Pellets of this rubber were controlled burned at temperature of 1000 deg C, and a catalyst system was used to synthesize the nanomaterials. CNTs are materials with a wide range of potential applications due to their extraordinary mechanical, thermal and electrical properties. Produced materials were characterized by SEM and TEM, and the hydrocarbons emissions were measured using GC. Results showed that materials with diameters of 30-100 nm and lengths of about 30 {mu}m were formed. That materials presented similar structures of multi-walled CNTs. Therefore, the use of SBR to produce carbon nanotubes showed quite satisfactory and an interesting field for future investments. (author)

  4. Synthesis and characterization of miktoarm star copolymer of styrene and butadiene using multifunctional macromolecular initiator

    Institute of Scientific and Technical Information of China (English)

    Hai Yan Zhang; Xing Ying Zhang

    2009-01-01

    A new kind of multifunctional macromolecular initiator with Sn-C bonds and polydiene arms was synthesized by living anionic polymerization.At first,polydiene-stannum chloride(PD-SnCl3)was prepared by the reaction of n-butyl-Li(n-BuLi),stannic chloride(SnCl4)and diene.Then PD-SnCl3 was used to react with the dilithium initiator to prepare the multifunctional organic macromolecular initiators.The result suggested that the initiators had a remarkable yield by GPC,nearly 90%.By using these multifunctional macromolecular initiators,styrene and butadiene were effectively polymerized via anionic polymerization,which gave birth to novel miktoarm star copolymers.The relative molecular weight and polydispersity index,microstructure contents,copolymerization components,glass transition temperature(Tg)and morphology of the miktoarm star copolymers were investigated by GPC-UV,1H NMR,DSC and TEM,respectively.

  5. Experimental thermal transport evolution of silane activated nano-clay reinforced styrene butadiene elastomeric nanocomposites

    Science.gov (United States)

    Iqbal, S. S.; Iqbal, N.; Jamil, T.; Bashir, A.; Shahid, M.

    2016-08-01

    In this study, silane activated nanoclay was reinforced in styrene butadiene rubber (SBR) to enhance the thermal resistance/stability and mechanical properties of SBR. silane activated nanoclay with variant concentrations was impregnated in the rubber matrix to fabricate polymer nanocomposites under control processing conditions. Experimental thermal transport, thermal oxidation, phase transition study, and mechanical properties of the nanocomposite specimens were carried out. Thermal insulation, thermal stability, and heat flow response were remarkably enhanced with the addition of nanokaolinite in the polymer matrix. Phase transition temperatures, their corresponding enthalpies, tensile strength, elastic modulus, elongation at break and hardness of the rubber composites were positively influenced with the filler incorporation into the host matrix. The Even dispersion of nanoreinforcements, morphological and compositional analyses of the thermal transport tested specimens were performed using scanning electron microscopy and energy dispersive spectroscopy, respectively.

  6. Analysis of recycled poly (styrene-co-butadiene) sulfonation: a new approach in solid catalysts for biodiesel production

    OpenAIRE

    Aguilar-Garnica, Efrén; Paredes-Casillas, Mario; Herrera-Larrasilla, Tito E; Rodríguez-Palomera, Felicia; Ramírez-Arreola, Daniel E

    2013-01-01

    The disposal of solid waste is a serious problem worldwide that is made worse in developing countries due to inadequate planning and unsustainable solid waste management. In Mexico, only 2% of total urban solid waste is recycled. One non-recyclable material is poly (styrene-co-butadiene), which is commonly used in consumer products (like components of appliances and toys), in the automotive industry (in instrument panels) and in food services (e.g. hot and cold drinking cups and glasses). In ...

  7. Fire and Gas Barrier Properties of Poly(styrene-co-acrylonitrile Nanocomposites Using Polycaprolactone/Clay Nanohybrid Based-Masterbatch

    Directory of Open Access Journals (Sweden)

    S. Benali

    2008-01-01

    Full Text Available Exfoliated nanocomposites are prepared by dispersion of poly(ε-caprolactone (PCL grafted montmorillonite nanohybrids used as masterbatches in poly(styrene-co-acrylonitrile (SAN. The PCL-grafted clay nanohybrids with high inorganic content are synthesized by in situ intercalative ring-opening polymerization of ε-caprolactone between silicate layers organomodified by alkylammonium cations bearing two hydroxyl functions. The polymerization is initiated by tin alcoholate species derived from the exchange reaction of tin(II bis(2-ethylhexanoate with the hydroxyl groups borne by the ammonium cations that organomodified the clay. These highly filled PCL nanocomposites (25 wt% in inorganics are dispersed as masterbatches in commercial poly(styrene-co-acrylonitrile by melt blending. SAN-based nanocomposites containing 3 wt% of inorganics are accordingly prepared. The direct blend of SAN/organomodified clay is also prepared for sake of comparison. The clay dispersion is characterized by wide-angle X-ray diffraction (WAXD, atomic force microscopy (AFM, and solid state NMR spectroscopy measurements. The thermal properties are studied by thermogravimetric analysis. The flame retardancy and gas barrier resistance properties of nanocomposites are discussed both as a function of the clay dispersion and of the matrix/clay interaction.

  8. Carboxyl-terminated butadiene-acrylonitrile-toughened epoxy/carboxyl-modified carbon nanotube nanocomposites: Thermal and mechanical properties

    Directory of Open Access Journals (Sweden)

    H. F. Xie

    2012-09-01

    Full Text Available Carboxyl-modified multi-walled carbon nanotubes (MWCNT–COOHs as nanofillers were incorporated into diglycidyl ether of bisphenol A (DGEBA toughened with carboxyl-terminated butadiene-acrylonitrile (CTBN. The carboxyl functional carbon nanotubes were characterized by Fourier-transform infrared spectroscopy and thermogravimetric analysis. Furthermore, cure kinetics, glass transition temperature (Tg, mechanical properties, thermal stability and morphology of DGEBA/CTBN/MWCNT–COOHs nanocomposites were investigated by differential scanning calorimetry (DSC, dynamic mechanical analysis (DMA, universal test machine, thermogravimetric analysis and scanning electron microscopy (SEM. DSC kinetic studies showed that the addition of MWCNT–COOHs accelerated the curing reaction of the rubber-toughened epoxy resin. DMA results revealed that Tg of rubber-toughened epoxy nanocomposites lowered with MWCNT–COOH contents. The tensile strength, elongation at break, flexural strength and flexural modulus of DGEBA/CTBN/MWCNT-COOHs nanocomposites were increased at lower MWCNT-COOH concentration. A homogenous dispersion of nanocomposites at lower MWCNT–COOH concentration was observed by SEM.

  9. A COMPARISON BETWEEN THE MORPHOLOGY OF SEMICRYSTALLINE POLYMER BLENDS OF POLY(EPSILON-CAPROLACTONE)/POLY(VINYL METHYL-ETHER) AND POLY(EPSILON-CAPROLACTONE)/(STYRENE-ACRYLONITRILE)

    NARCIS (Netherlands)

    OUDHUIS, AACM; THIEWES, HJ; VANHUTTEN, PF; TENBRINKE, G

    1994-01-01

    The morphology of polymer blends of poly(epsilon-caprolactone) (PCL) and poly(vinyl methyl ether) (PVME) is compared with that of PCL and a random copolymer of styrene and acrylonitrile (SAN). The main objective is to determine the influence of the glass transition temperature of the amorphous compo

  10. Devulcanization of styrene butadiene rubber by microwave energy: Effect of the presence of ionic liquid

    Directory of Open Access Journals (Sweden)

    S. Seghar

    2015-12-01

    Full Text Available In this study, styrene butadiene rubber (SBR was devulcanized using microwave irradiation. In particular, effect of ionic liquid (IL, pyrrolidinium hydrogen sulfate [Pyrr][HSO4], on the devulcanization performance was studied. It was observed that the evolution of the temperature reached by rubber powder exposed to microwave irradiation for different energy values was favored by the presence of ionic liquid [Pyrr][HSO4] significantly over the whole range of the microwave energy values. Beyond the threshold point of 220 Wh/kg, the soluble fraction after devulcanization sharply increased with increasing devulcanization microwave energy. For the powder mixed with [Pyrr][HSO4], the increase was more significant. Furthermore, the crosslink density was observed to decrease slowly with the microwave energy up to 220 Wh/kg, beyond which the crosslink density decreased significantly for the rubber impregnated with IL. For the rubber with IL, significant and continuous increase in Tg with microwave energy values was observed in comparison with the SBR where no change in transition temperature was observed. Mechanical shearing of rubber gums in the two-roll mill favored the devulcanization process, which indicated that the combination of mechanical loading with microwave energy and IL is an efficient procedure allowing an optimal devulcanization of rubbers.

  11. Bond Characteristics of Macro Polypropylene Fiber in Cementitious Composites Containing Nanosilica and Styrene Butadiene Latex Polymer

    Directory of Open Access Journals (Sweden)

    Jae-Woong Han

    2015-01-01

    Full Text Available This study evaluated the bond properties of polypropylene (PP fiber in plain cementitious composites (PCCs and styrene butadiene latex polymer cementitious composites (LCCs at different nanosilica contents. The bond tests were evaluated according to JCI SF-8, in which the contents of nanosilica in the cement were 0, 2, 4, 6, 8, and 10 wt%, based on cement weight. The addition of nanosilica significantly affected the bond properties between macro PP fiber and cementitious composites. For PCCs, the addition of 0–2 wt% nanosilica enhanced bond strength and interface toughness, whereas the addition of 4 wt% or more reduced bond strength and interface toughness. The bond strength and interfacial toughness of LCCs also increased with the addition of up to 6% nanosilica. The analysis of the relative bond strength showed that the addition of nanosilica affects the bond properties of both PCC and LCC. This result was confirmed via microstructural analysis of the macro PP fiber surface after the bond tests, which revealed an increase in scratches due to frictional forces and fiber tearing.

  12. Mechanical and Thermal Properties of Styrene Butadiene Rubber - Functionalized Carbon Nanotubes Nanocomposites

    KAUST Repository

    Laoui, Tahar

    2013-01-01

    The effect of reinforcing styrene butadiene rubber (SBR) with functionalized carbon nanotubes on the mechanical and thermal properties of the nanocomposite was investigated. Multi-walled carbon nanotubes (CNTs) were functionalized with phenol functional group to enhance their dispersion in SBR matrix. Surface functionalization of the CNTs was carried out using acid treatment and FTIR technique was utilized so as to ascertain the presence of phenol functional group. This was followed with the dispersion of the functionalized CNTs into a polymer solution and a subsequent evaporation of the solvent. This study has demonstrated the inherent capability of CNTs as reinforcing filler as demonstrated by the substantial improvement in Young\\'s Modulus, tensile strength and energy of absorption of the nanocomposites. The tensile strength increased from 0.17 MPa (SBR) to 0.48 MPa while the Young\\'s Modulus increased from 0.25 MPa to 0.83 MPa when 10wt% functionalized CNTs was added. With the addition of 1wt% reinforcement-a peak value of 4.1 KJ energy absorption was obtained. The homogenous dispersion of CNT-Phenol is thought to be responsible for the considerable enhancement in the reported properties. Copyright © Taylor & Francis Group, LLC.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-08-15

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

  14. Styrene-butadiene rubber/halloysite nanotubes nanocomposites modified by methacrylic acid

    Energy Technology Data Exchange (ETDEWEB)

    Guo Baochun [Department of Polymer Materials and Engineering, South China University of Technology, Guangzhou 510640 (China)], E-mail: psbcguo@scut.edu.cn; Lei Yanda; Chen Feng; Liu Xiaoliang; Du Mingliang; Jia Demin [Department of Polymer Materials and Engineering, South China University of Technology, Guangzhou 510640 (China)

    2008-12-30

    Methacrylic acid (MAA) was used to improve the performance of styrene-butadiene rubber (SBR)/halloysite nanotubes (HNTs) nanocomposites by direct blending. The detailed interaction mechanisms of MAA and the in situ formed zinc methacrylate (ZDMA) were revealed by X-ray diffraction (XRD), surface area and porosity analysis, X-ray photoelectron spectroscopy (XPS) together with crosslink density determination. The strong interfacial bonding between HNTs and rubber matrix is resulted through ZDMA and MAA intermediated linkages. ZDMA connects SBR and HNTs via grafting/complexation mechanism. MAA bonds SBR and HNTs through grafting/hydrogen bonding mechanism. Significantly improved dispersion of HNTs in virtue of the interactions between HNTs and MAA or ZDMA was achieved. Effects of MAA content on the vulcanization behavior, morphology and mechanical properties of the nanocomposites were investigated. Promising mechanical properties of MAA modified SBR/HNTs nanocomposites were obtained. The changes in vulcanization behavior, mechanical properties and morphology were correlated with the interactions between HNTs and MAA or ZDMA and the largely improved dispersion of HNTs.

  15. MORPHOLOGY, INTERFACIAL INTERACTION AND PROPERTIES OF STYRENE-BUTADIENE RUBBER/MODIFIED HALLOYSITE NANOTUBE NANOCOMPOSITES

    Institute of Scientific and Technical Information of China (English)

    Zhi-xin Jia; Yuan-fang Luo; Shu-yan Yang; Bao-chun Guo; Ming-liang Du; De-min Jia

    2009-01-01

    A natural nanotubular material, halloysite nanotubes (HNTs), was introduced to prepare styrene-butadiene rubber/modified halloysite nanotube (SBR/m-HNT) nanocomposites. Complex of resorcinol and hexamethylenetetramine (RH) was used as the interracial modifier. The structure, morphology and mechanical properties of SBR/m-HNT nanocomposites, especially the interfacial interactions, were investigated. SEM and TEM observations showed that RH can not only facilitate the dispersion and orientation of HNTs in SBR matrix at nanometer scale, but also enhance the interracial combination between HNTs and rubber matrix. FTIR and XPS investigations confirmed that a number of hydrogen bonds were formed between the phenol hydroxyl groups in resorcinol-formaldehyde resin derived from RH and the oxygen atoms in Si-O bonds or hydroxyl groups on HNTs surfaces. The m-HNTs modified with RH have significant reinforcing effect on SBR vulcanizates. RH as a good interfacial modifier can remarkably improve mechanical properties of SBR/HNT composites. The substantial improvement of comprehensive properties for SBR/m-HNT nanocomposites can be attributed to good dispersion and orientation of HNTs in SBR matrix at nanometer scale and the enhanced interracial interaction between HNTs and rubber matrix.

  16. Thermal Stability and Flammability of Styrene-Butadiene Rubber-Based (SBR Ceramifiable Composites

    Directory of Open Access Journals (Sweden)

    Rafał Anyszka

    2016-07-01

    Full Text Available Ceramifiable styrene-butadiene (SBR-based composites containing low-softening-point-temperature glassy frit promoting ceramification, precipitated silica, one of four thermally stable refractory fillers (halloysite, calcined kaolin, mica or wollastonite and a sulfur-based curing system were prepared. Kinetics of vulcanization and basic mechanical properties were analyzed and added as Supplementary Materials. Combustibility of the composites was measured by means of cone calorimetry. Their thermal properties were analyzed by means of thermogravimetry and specific heat capacity determination. Activation energy of thermal decomposition was calculated using the Flynn-Wall-Ozawa method. Finally, compression strength of the composites after ceramification was measured and their micromorphology was studied by scanning electron microscopy. The addition of a ceramification-facilitating system resulted in the lowering of combustibility and significant improvement of the thermal stability of the composites. Moreover, the compression strength of the mineral structure formed after ceramification is considerably high. The most promising refractory fillers for SBR-based ceramifiable composites are mica and halloysite.

  17. Application of Composite Powders Recycled from Graphite Tailings in Styrene-Butadiene Rubber

    Science.gov (United States)

    Hai, Yun; Liao, Libing; Lv, Guocheng; Qin, Faxiang; Mei, Lefu; Wei, Yaozu

    2015-11-01

    With styrene-butadiene rubber (SBR) as matrix and composite powders recycled from graphite tailings as fillers, the influence of the particle size and content of the composite powders on the tensile strength and electrical conductivity of the composite powder-filled SBR were studied. The results showed that composite powder recycled from graphite tailings could reinforce SBR, whose tensile strength was significantly increased with reducing the particle size of the composite powder, but it had little effect on the conductivity of the system. With composite powders as fillers in conjunction with conductive carbon black, the tensile strength and electrical conductivity of the system were greatly improved. The maximum tensile strength of the SBR filled with composite powder and conductive carbon black increased by 47% compared to that of the single composite powder-filled SBR. When the filling content of conductive carbon black was 10 phr and that of composite powder was above 30 phr, the volume resistivity of SBR showed a sharp decline, reaching a minimum about 106 Ω cm at 40 phr. All the results indicated that composite powder recycled from graphite tailings can be applied effectively as filler in SBR. It has great economic and environmental benefits.

  18. Power Efficient, Restart-Capable Acrylonitrile-Butadiene-Styrene Arc Ignitor for Hybrid Rockets

    OpenAIRE

    Whitmore, Stephen; Merkely, Daniel; Inkley, Nathan

    2014-01-01

    Because hybrid rocket propellant materials are individually chemically stable prior to mixing within the combustion chamber, these systems possess well-known safety advantages. Unfortunately, the relative stability of traditional hybrid propellants also makes hybrid systems difficult to ignite. Hybrid ignition has historically involved one of three means, 1) pyrotechnic charges, 2) plasma torch, and 3) electric spark plugs with bi-propellant injectors. All of these methods possess distinct di...

  19. Radiation-induced copolymerization of styrene/ n-butyl acrylate in the presence of ultra-fine powdered styrene-butadiene rubber

    Science.gov (United States)

    Yu, Haibo; Peng, Jing; Zhai, Maolin; Li, Jiuqiang; Wei, Genshuan; Qiao, Jinliang

    2007-11-01

    Styrene (St)/ n-butyl acrylate (BA) copolymers were prepared by two-stage polymerization: St/BA was pre-polymerized to a viscous state by bulk polymerization with initiation by benzoyl peroxide (BPO) followed by 60Co γ-ray radiation curing. The resultant copolymers had higher molecular weight and narrower molecular weight distribution than conventional methods. After incorporation of ultra-fine powdered styrene-butadiene rubber (UFSBR) with a particle size of 100 nm in the monomer, the glass transition temperature ( Tg) of St-BA copolymer increased at low rubber content. Both the St-BA copolymer and the St-BA copolymer/UFSBR composites had good transparency at BA content below 40%.

  20. Variation of long periodicity in blends of styrene butadiene, styrene copolymer/polyaniline using small angle X-ray scattering data

    Indian Academy of Sciences (India)

    B G Soares; Fernando G Souza Jr; A Manjunath; H Somashekarappa; R Somashekar; Siddaramaiah

    2007-09-01

    Small angle X-ray scattering data have been recorded for the blends of styrene butadiene, styrene copolymer/polyaniline using the beamline of the LNLS (Laboratorio Nacional de Luz sincroton-Campinas, Brazil). Employing one-dimensional Hosemann's paracrystalline model, we have simulated the meridional reflections of these blends in order to compute the long periodicity and hence to find the variation with concentrations of the blends. Within the region of available experimental data we observe that there is a linear relationship between long periodicity and concentration of blends. These parameters are compared with physical measurements like tensile strength to find the structure–property relation in these blends.

  1. Glass Transition and Molecular Mobility in Styrene-Butadiene Rubber Modified Asphalt.

    Science.gov (United States)

    Khabaz, Fardin; Khare, Rajesh

    2015-11-01

    Asphalt, a soft matter consisting of more than a thousand chemical species, is of vital importance for the transportation infrastructure, yet it poses significant challenges for microscopic theory and modeling approaches due to its multicomponent nature. Polymeric additives can potentially enhance the thermo-mechanical properties of asphalt, thus helping reduce the road repair costs; rational design of such systems requires knowledge of the molecular structure and dynamics of these systems. We have used molecular dynamics (MD) simulations to investigate the volumetric, structural, and dynamic properties of the neat asphalt as well as styrene-butadiene rubber (SBR) modified asphalt systems. The volume-temperature behavior of the asphalt systems exhibited a glass transition phenomenon, akin to that observed in experiments. The glass transition temperature, room temperature density, and coefficient of volume thermal expansion of the neat asphalt systems so evaluated were in agreement with experimental data when the effect of the high cooling rate used in simulations was accounted for. While the volumetric properties of SBR modified asphalt were found to be insensitive to the presence of the SBR additive, the addition of SBR led to an increase in the aggregation of asphaltene molecules. Furthermore, addition of SBR caused a reduction in the mobility of the constituent molecules of asphalt, with the reduction being more significant for the larger constituent molecules. Similar to other glass forming liquids, the reciprocal of the diffusion coefficient of the selected molecules was observed to follow the Vogel-Fulcher-Tammann (VFT) behavior as a function of temperature. These results suggest the potential for using polymeric additives for enhancing the dynamic mechanical properties of asphalt without affecting its volumetric properties. PMID:26451630

  2. Mechanical performance of styrene-butadiene-rubber filled with carbon nanoparticles prepared by mechanical mixing

    Energy Technology Data Exchange (ETDEWEB)

    Saatchi, M.M. [Department of Chemical and Petroleum Engineering, Sharif University of Technology, P.O. Box 11155-9465, Tehran (Iran, Islamic Republic of); Shojaei, A., E-mail: akbar.shojaei@sharif.edu [Department of Chemical and Petroleum Engineering, Sharif University of Technology, P.O. Box 11155-9465, Tehran (Iran, Islamic Republic of)

    2011-09-15

    Highlights: {yields} We compare influence of carbon blacks and carbon nanotube on properties of SBR. {yields} We model mechanical behavior of SBR nanocomposites by the micromechanical model. {yields} Mechanical properties of carbon black/SBR is greatly dominated by bound rubber. {yields} Mechanical properties of SBR/nanotube is governed by big aspect ratio of nanotube. - Abstract: Reinforcement of styrene-butadiene-rubber (SBR) was investigated using two different carbon blacks (CBs) with similar particle sizes, including highly structured CB and conventional CB, as well as multi-walled carbon nanotube (MWCNT) prepared by mechanical mixing. The attempts were made to examine reinforcing mechanism of these two different classes of carbon nanoparticles. Scanning electron microscopy and electrical conductivity measurement were used to investigate morphology. Tensile, cyclic tensile and stress relaxation analyses were performed. A modified Halpin-Tsai model based on the concept of an equivalent composite particle, consisting of rubber bound, occluded rubber and nanoparticle, was proposed. It was found that properties of CB filled SBR are significantly dominated by rubber shell and occluded rubber in which molecular mobility is strictly restricted. At low strains, these rubber constituents can contribute in hydrodynamic effects, leading to higher elastic modulus. However, at higher strains, they contribute in stress hardening resulting in higher elongation at break and higher tensile strength. These elastomeric regions can also influence stress relaxation behaviors of CB filled rubber. For SBR/MWCNT, the extremely great inherent mechanical properties of nanotube along with its big aspect ratio were postulated to be responsible for the reinforcement while their interfacial interaction was not so efficient.

  3. Stepwise Swelling of a Thin Film of Lamellae-Forming Poly(styrene-b-butadiene) in Cyclohexane Vapor

    DEFF Research Database (Denmark)

    Di, Zhenyu; Posselt, Dorthe; Smilgies, Detlef-M.;

    2012-01-01

    We investigated the swelling of a thin film of lamellae-forming poly(styrene-b-butadiene) in cyclohexane vapor. The vapor pressure and thus the degree of swelling of the film are increased in a stepwise manner using a custom-built sample cell. The resulting structural changes during and after each...... normal has a sharp maximum. These observations point to the formation of new lamellae. During the subsequent swelling steps, the lamellar thickness overshoots only weakly. The behavior thus resembles qualitatively our previous results on a similar thin film during swelling in saturated vapor...

  4. Analysis of recycled poly (styrene-co-butadiene) sulfonation: a new approach in solid catalysts for biodiesel production.

    Science.gov (United States)

    Aguilar-Garnica, Efrén; Paredes-Casillas, Mario; Herrera-Larrasilla, Tito E; Rodríguez-Palomera, Felicia; Ramírez-Arreola, Daniel E

    2013-01-01

    The disposal of solid waste is a serious problem worldwide that is made worse in developing countries due to inadequate planning and unsustainable solid waste management. In Mexico, only 2% of total urban solid waste is recycled. One non-recyclable material is poly (styrene-co-butadiene), which is commonly used in consumer products (like components of appliances and toys), in the automotive industry (in instrument panels) and in food services (e.g. hot and cold drinking cups and glasses). In this paper, a lab-scale strategy is proposed for recycling poly (styrene-co-butadiene) waste by sulfonation with fuming sulfuric acid. Tests of the sulfonation strategy were carried out at various reaction conditions. The results show that 75°C and 2.5 h are the operating conditions that maximize the sulfonation level expressed as number of acid sites. The modified resin is tested as a heterogeneous catalyst in the first step (known as esterification) of biodiesel production from a mixture containing tallow fat and canola oil with 59% of free fatty acids. The preliminary results show that esterification can reach 91% conversion in the presence of the sulfonated polymeric catalyst compared with 67% conversion when the reaction is performed without catalyst. PMID:24098857

  5. The Structure of the Free Volume in Poly(styrene-co-acrylonitrile) from Positron Lifetime and Pressure Volume Temperature (PVT) Experiments

    OpenAIRE

    Dlubek, Gunter; Bondarenko, Vladimir; Al-Qaradawi, Ilham Y.; Kilburn, Duncan; Krause-Rehberg, Reinhard

    2004-01-01

    Summary: The structure of the free volume and its temperature dependence between 25 and 190 °C of copolymers of styrene with acrylonitrile, SAN (0 to 50 mol-% AN), is studied by pressure volume temperature (PVT) experiments and positron annihilation lifetime spectroscopy (PALS). In this second part of the work, PALS data are reported from which the temperature dependence of the mean size and size distribution of local free volumes (subnanometer size holes) is analysed. The mean hole volume, v...

  6. Preparation of acrylonitrile butadiene rubber by soap-free emulsion polymerization%无皂乳液聚合制备丁二烯-丙烯腈橡胶

    Institute of Scientific and Technical Information of China (English)

    桂强; 梁琨; 钟启林; 马朋高; 张元寿; 王真琴

    2011-01-01

    In this paper,soap-free acrylonitrile butadiene rubber was prepared using sulfate polymerisable emulsifier KD SE-10 by emulsion copolymerization at low temperature. The article studied the influence of the amount of polymerisable emulsifier on mooney viscosity, bound acrylonitrile content, the gel ratio, tensile strength and molecular weight. And the amount of KD SE-10 was determined as 2. 7%~3.0wt%. Acrylonitrile butadiene rubber prepared has the remarkable characteristics of high-strength,excellent oil resistance and narrow molecular weight distribution.%采用硫酸盐类可聚合乳化剂烯丙氧基壬基苯氧基丙醇聚氧乙烯醚硫酸铵(KD SE-10)通过低温乳液聚合法制备无皂丁腈橡胶.详细考察了可聚合乳化剂用量对门尼粘度、结合丙烯腈含量、凝胶量、拉伸强度、相对分子质量的影响情况,并确定了KD SE-10用量为2.7%~3.0%(质量分数).制得的无皂丁腈橡胶相比普通丁腈橡胶具有显著的高强度、更优良的耐油性、相对分子质量分布窄的特点.

  7. Volume shrinkage and rheological studies of epoxidised and unepoxidised poly(styrene-block-butadiene-block-styrene) triblock copolymer modified epoxy resin-diamino diphenyl methane nanostructured blend systems.

    Science.gov (United States)

    George, Sajeev Martin; Puglia, Debora; Kenny, Josè M; Parameswaranpillai, Jyotishkumar; Vijayan P, Poornima; Pionteck, Jűrgen; Thomas, Sabu

    2015-05-21

    Styrene-block-butadiene-block-styrene (SBS) copolymers epoxidised at different epoxidation degrees were used as modifiers for diglycidyl ether of the bisphenol A-diamino diphenyl methane (DGEBA-DDM) system. Epoxy systems containing modified epoxidised styrene-block-butadiene-block-styrene (eSBS) triblock copolymer with compositions ranging from 0 to 30 wt% were prepared and the curing reaction was monitored in situ using rheometry and pressure-volume-temperature (PVT) analysis. By controlling the mole percent of epoxidation, we could generate vesicles, worm-like micelles and core-shell nanodomains. At the highest mole percent of epoxidation, the fraction of the epoxy miscible component in the triblock copolymer (epoxidised polybutadiene (PB)) was maximum. This gave rise to core-shell nanodomains having a size of 10-15 nm, in which the incompatible polystyrene (PS) becomes the core, the unepoxidised PB becomes the shell and the epoxidised PB interpenetrates with the epoxy phase. On the other hand, the low level of epoxidation gave rise to bigger domains having a size of ∼1 μm and the intermediate epoxidation level resulted in a worm-like structure. This investigation specifically focused on the importance of cure rheology on nanostructure formation, using rheometry. The reaction induced phase separation of the PS phase in the epoxy matrix was carefully explored through rheological measurements. PVT measurements during curing were carried out to understand the volume shrinkage of the blend, confirming that shrinkage behaviour is related to the block copolymer phase separation process during curing. The volume shrinkage was found to be maximum in the case of blends with unmodified SBS, where a heterogeneous morphology was observed, while a decrease in the shrinkage was evidenced in the case of SBS epoxidation. It could be explained by two effects: (1) solubility of the epoxidised block copolymer in the DGEBA leads to the formation of nanoscopic domains upon

  8. Inner Stucture of Thin Films of Lamellar Poly(styrene-b-butadiene) Diblock Copolymers as revealed by Grazing-Incidence Small-Angle Scattering

    DEFF Research Database (Denmark)

    Busch, Peter; Posselt, Dorthe; Smilgies, Detlef-Matthias;

    2007-01-01

    The lamellar orientation in supported, thin films of poly(styrene-b-butadiene) (P(S-b-B)) depends on block copolymer molar mass. We have studied films from nine block copolymer samples with molar masses between 13.9 and 183 kg/mol using grazing-incidence small-angle X-ray scattering (GISAXS) and ...

  9. Carbon Nanotube-thermally Reduced Graphene Hybrid/Styrene Butadiene Rubber Nano Composites: Mechanical, Morphological and Dielectric Studies

    Directory of Open Access Journals (Sweden)

    Jiji Abraham

    2015-07-01

    Full Text Available Styrene Butadiene Rubber composites with mixture of carbon nanotube and thermally reduced graphene were prepared and morphological, mechanical and dielectric properties of the composites were studied. Aim of this study is to understand the dispersion and reinforcement behaviour of hybrid filler in rubber matrix. Improved mechanical properties in the presence of graphene are due to the good dispersion and improved compatibility with the matrix. The formation of a mixed filler network showed a synergistic effect on the improvement of electrical as well as various mechanical properties. This method provides a simple route to enhance the dispersion of carbon nanotubes and to improve the electrical property of the polymer composites. It is concluded that introduction of thermally reduced graphene to CNT-SBR composites can improve the mechanical properties of the composites up to an optimum concentration of the graphene after that performance will be diminished due to the agglomeration of graphene.

  10. Processing of styrene butadiene rubber-carbon black nanocomposites with gradation of crosslink density: Static and dynamic mechanical characterization

    International Nuclear Information System (INIS)

    The concentrations of sulfur and accelerator were varied in the nanocomposites of carbon black (CB)-filled styrene-butadiene rubber (SBR) matrix to introduce the gradation of the crosslink density. These curatives were varied from 1 to 11 phr (per hundred rubber) along the span of 3-mm thick sheet using the construction-based layering method. The static and dynamic mechanical characterizations of these functionally graded polymeric nanocomposites (FGPNCs) were carried out. With increasing crosslink density along thickness, hardness and modulus increase while the ultimate properties like tensile strength and elongation at break droop down. The dynamic mechanical analysis of FGPNCs exhibits the increment in the storage modulus than the uniformly dispersed polymeric nanocomposites (UDPNCs) employing the same average amount of curatives. The peak position of tan δmax remains at the same temperature while the value mitigates in FGPNCs. In FGPNCs, tan δ peak intimates the broadness in the transition region

  11. Processing of styrene butadiene rubber-carbon black nanocomposites with gradation of crosslink density: Static and dynamic mechanical characterization

    Energy Technology Data Exchange (ETDEWEB)

    Ahankari, S.S. [Advanced Nano Engineering Materials Laboratory, Materials Science Programme, Indian Institute of Technology Kanpur, Kanpur 208016 (India); Kar, Kamal K. [Advanced Nano Engineering Materials Laboratory, Materials Science Programme, Indian Institute of Technology Kanpur, Kanpur 208016 (India); Advanced Nano Engineering Materials Laboratory, Materials Science Programme and Department of Mechanical Engineering, Indian Institute of Technology Kanpur, Kanpur 208016 (India)], E-mail: kamalkk@iitk.ac.in

    2008-09-15

    The concentrations of sulfur and accelerator were varied in the nanocomposites of carbon black (CB)-filled styrene-butadiene rubber (SBR) matrix to introduce the gradation of the crosslink density. These curatives were varied from 1 to 11 phr (per hundred rubber) along the span of 3-mm thick sheet using the construction-based layering method. The static and dynamic mechanical characterizations of these functionally graded polymeric nanocomposites (FGPNCs) were carried out. With increasing crosslink density along thickness, hardness and modulus increase while the ultimate properties like tensile strength and elongation at break droop down. The dynamic mechanical analysis of FGPNCs exhibits the increment in the storage modulus than the uniformly dispersed polymeric nanocomposites (UDPNCs) employing the same average amount of curatives. The peak position of tan {delta}{sub max} remains at the same temperature while the value mitigates in FGPNCs. In FGPNCs, tan {delta} peak intimates the broadness in the transition region.

  12. Comparison of nano CaCO{sub 3} and flyash filled with styrene butadiene rubber on mechanical and thermal properties

    Energy Technology Data Exchange (ETDEWEB)

    S. Mishra; N.G. Shimpi

    2005-10-01

    Different particle sizes (21, 15, 9 nm) of CaCO{sub 3} were synthesized by in-situ deposition technique and confirmed by X-ray diffraction method. The nano CaCO{sub 3} was added from 0.1 wt % to 0.5 wt % in the styrene butadiene rubber (SBR). Rubber nanocomposties were compounded on two-roll mill and molded in compression molding machine. Mechanical properties such as tensile strength, elongation at break, modulus at 300 % elongation, hardness, specific gravity, swelling index, flame retardency and abrasion resistance were studied. These results were compared with flyash filled SBR. There was an improvement in properties of rubber nanocomposites because of uniform dispersion of nano CaCO{sub 3} particles in the matrix that intercalates the rubber chains. Hence degree of crosslinking increases multifold in comparison to commercial CaCO{sub 3} and flyash.

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

    International Nuclear Information System (INIS)

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

  14. Studies on blends of cycloaliphatic epoxy resin with varying concentrations of carboxyl terminated butadiene acrylonitrile copolymer I: Thermal and morphological properties

    Indian Academy of Sciences (India)

    Garima Tripathi; Deepak Srivastava

    2009-04-01

    Differential scanning calorimetric (DSC), thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA) of the blends of cycloaliphatic epoxy (CAE) resin toughened with liquid elastomer such as carboxyl terminated butadiene acrylonitrile copolymer (CTBN) have been carried out. Exothermal heat of reaction due to cross linking of the resin in the presence of diamino diphenyl sulphone (DDS, an amine hardener) showed a decreasing trend with increasing rubber concentration. Enhancement of thermal stability as well as lower mass loss of the epoxy–rubber blends with increasing rubber concentration have been observed in thermogravimetric analysis (TGA). Dynamic mechanical properties reflected a monotonic decrease in the storage modulus (′) with increasing rubber concentration. The loss modulus (″) and the loss tangent (tan ) values, however, showed an increasing trend with rise of temperature up to a maximum (peak) followed by a gradual fall in both cases.

  15. Production,research and development of oil-extended styrene-butadiene rubber%充油丁苯橡胶生产及研发现状

    Institute of Scientific and Technical Information of China (English)

    白玉光; 王玉瑛; 李树丰

    2011-01-01

    充油丁苯橡胶具有加工性能好、生热低、低温挠屈性好等特点,尤其用于胎面胶时,具有优异的牵引性能和耐磨耗性,在乳聚丁苯橡胶(ESBR)的生产中占据重要位置.本文概述了目前国内充油丁苯橡胶的生产及消费情况,并对国内充油丁苯橡胶的研发现状进行了小结,对充油丁苯橡胶的发展提出了建议.%Oil-extended styrene-butadiene rubber is a leading rubber during ESBR production because of its good processability, low heat generation, cold flexibility, especially excellent traction and abrasion loss as tread rubber. This paper briefly describes production, consumption, research and development of oil-extended styrene-butadiene rubber in China, and proposes some advices on oil-extended styrene-butadiene rubber development.

  16. Plane-interface-induced lignin-based nanosheets and its reinforcing effect on styrene-butadiene rubber

    Directory of Open Access Journals (Sweden)

    C. Jiang

    2014-09-01

    Full Text Available Lignin was viewed as a spherical microgel in aqueous alkali. While spread out in a monolayer or adsorbed on a surface, lignin was made up of flexible, disk-like molecules with approximately the same thickness of 2 nm. According to this principle, we employed the lamina of montmorillonite (MMT as a plane template to anchor cationic lignin (CL on its two sides, resulting in the formation of CL-MMT hybrid materials (CLM. The isotherm adsorption behavior and structure characteristics of CLM were studied. The results showed that CLM was individually dispersed nanosheets with a thickness of about 5 nm when the mass ratio of CL to MMT is more than 2:1 and prepared at acidic or neutral pH. Compared to the cocoagulation of lignin and styrene-butadiene rubber (SBR, CLM obviously accelerated the coagulation rate, due to the reduction of surface activity of CL restricted by MMT. The nanoscale dispersion of CLM in SBR matrix significantly improved the tensile strength of CLM/SBR nanocomposites to 14.1 MPa by adding only 10 phr CLM and cardanol glycidyl ether (CGE as compatibilizer. Dynamic mechanical analysis (DMA showed that the glass transition temperature of SBR/CLM nanocomposites decreased with increasing CLM loading. Correspondingly, a special interfacial structure was proposed.

  17. Characterization on the phase separation behavior of styrene-butadiene rubber/polyisoprene/organoclay ternary blends under oscillatory shear

    Science.gov (United States)

    Liu, Xianggui; Dong, Xia; Liu, Wei; Xing, Qian; Zou, Fasheng; Han, Charles C.; Wang, Dujin; Liang, Aimin; Li, Chuanqing; Xie, Ximing

    2015-09-01

    The present work investigated the influence of organoclay (organo-montmorillonite, OMMT) on the phase separation behavior and morphology evolution of solution polymerized styrene-butadiene rubber (SSBR)/low vinyl content polyisoprene (LPI) blends with rheological methodology. It was found that the incorporation of OMMT not only reduced the droplet size of the dispersion phase, slowed down the phase separation kinetics, also enlarged the processing miscibility window of the blends. The determination on the wetting parameters indicated that due to the oscillatory shear effect, the OMMT sheets might localize at the interface between the two phases and act as compatibilizer or rigid barrier to prevent domain coarsening, resulting in slow phase separation kinetics, small droplet size, and stable morphology. The analysis of rheological data by the Palierne model provided further confirmation that the addition of OMMT can decrease the interfacial tension and restrict the relaxation of melt droplets. Therefore, a vivid "sea-fish-net" model was proposed to describe the effect of OMMT on the phase separation behavior of SSBR/LPI blends, in which the OMMT sheets acted as the barrier (net) to slow down the domain coarsening/coalescence in phase separation process of SSBR/LPI blends.

  18. Stepwise swelling of a thin film of lamellae-forming poly(styrene-b- butadiene) in cyclohexane vapor

    KAUST Repository

    Di, Zhenyu

    2012-06-26

    We investigated the swelling of a thin film of lamellae-forming poly(styrene-b-butadiene) in cyclohexane vapor. The vapor pressure and thus the degree of swelling of the film are increased in a stepwise manner using a custom-built sample cell. The resulting structural changes during and after each step were followed in situ using time-resolved grazing-incidence small-angle X-ray scattering (GISAXS). During the first step, the lamellar thickness increases strongly, before it decreases again. At the same time, the full width at half-maximum (FWHM) of the diffuse Bragg reflection along the film normal has a sharp maximum. These observations point to the formation of new lamellae. During the subsequent swelling steps, the lamellar thickness overshoots only weakly. The behavior thus resembles qualitatively our previous results on a similar thin film during swelling in saturated vapor of cyclohexane; however, it deviates from earlier theoretical predictions. We propose a theory that is quantitatively correct for the description of the dependence of the lamellar thickness on the polymer volume fraction in the late stage of the swelling steps. © 2012 American Chemical Society.

  19. Mortality of a cohort of workers in the styrene-butadiene polymer manufacturing industry (1943-1982)

    Energy Technology Data Exchange (ETDEWEB)

    Matanoski, G.M.; Santos-Burgoa, C.; Schwartz, L. (Johns Hopkins School of Hygiene and Public Health, Baltimore, MD (USA))

    1990-06-01

    A cohort of 12,110 male workers employed 1 or more years in eight styrene-butadiene polymer (SBR) manufacturing plants in the United States and Canada has been followed for mortality over a 40-year period, 1943 to 1982. The all-cause mortality of these workers was low (standardized mortality ratio (SMR) = 0.81) compared to that of the general population. However, some specific sites of cancers had SMRs that exceeded 1.00. These sites were then examined by major work divisions. The sites of interest included leukemia and non-Hodgkin's lymphoma in whites. The SMRs for cancers of the digestive tract were higher than expected, especially esophageal cancer in whites and stomach cancer in blacks. The SMR for arteriosclerotic heart disease in black workers was significantly higher than would be expected based on general population rates. Employees were assigned to a work area based on job longest held. The SMRs for specific diseases differed by work area. Production workers showed increased SMRs for hematologic neoplasms and maintenance workers, for digestive cancers. A significant excess SMR for arteriosclerotic heart disease occurred only in black maintenance workers, although excess mortality from this disease occurred in blacks regardless of where they worked the longest. A significant excess SMR for rheumatic heart disease was associated with work in the combined, all-other work areas. For many causes of death, there were significant deficits in the SMRs.

  20. Physico-mechanical properties and thermal stability of thermoset nanocomposites based on styrene-butadiene rubber/phenolic resin blend

    Energy Technology Data Exchange (ETDEWEB)

    Shojaei, Akbar, E-mail: akbar.shojaei@sharif.edu [Department of Chemical and Petroleum Engineering, Sharif University of Technology, P.O. Box 11155-9465, Tehran (Iran, Islamic Republic of); Faghihi, Morteza [Department of Chemical and Petroleum Engineering, Sharif University of Technology, P.O. Box 11155-9465, Tehran (Iran, Islamic Republic of)

    2010-02-15

    Effect of organoclay (OC) on the performance of styrene-butadiene rubber (SBR)/phenolic resin (PH) blend prepared by two-roll mill was investigated. The influence of OC content ranging between 2.5 and 30 phr on the performance of SBR/PH was investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), interfacial energy analysis, tensile, dynamic mechanical, swelling, cure rheometry and thermogravimetric analysis (TGA). It was found that the OC is mainly localized in the SBR phase of SBR/PH blend through the kinetically favored mechanism relevant to rubber chains. The results also demonstrated the positive role of PH on the dispersion of OC. Both PH and OC showed accelerating role on the cure rate of SBR and increased the crosslinking density of the rubber phase. Additionally, the mechanical and dynamic mechanical properties of SBR were influenced by incorporation of both PH and OC. TGA showed that the OC improves thermal stability of SBR vulcanizate, while it exhibits a catalytic role in presence of PH.

  1. The filler-rubber interface in styrene butadiene nanocomposites with anisotropic silica particles: morphology and dynamic properties.

    Science.gov (United States)

    Tadiello, L; D'Arienzo, M; Di Credico, B; Hanel, T; Matejka, L; Mauri, M; Morazzoni, F; Simonutti, R; Spirkova, M; Scotti, R

    2015-05-28

    Silica-styrene butadiene rubber (SBR) nanocomposites were prepared by using shape-controlled spherical and rod-like silica nanoparticles (NPs) with different aspect ratios (AR = 1-5), obtained by a sol-gel route assisted by a structure directing agent. The nanocomposites were used as models to study the influence of the particle shape on the formation of nanoscale immobilized rubber at the silica-rubber interface and its effect on the dynamic-mechanical behavior. TEM and AFM tapping mode analyses of nanocomposites demonstrated that the silica particles are surrounded by a rubber layer immobilized at the particle surface. The spherical filler showed small contact zones between neighboring particles in contact with thin rubber layers, while anisotropic particles (AR > 2) formed domains of rods preferentially aligned along the main axis. A detailed analysis of the polymer chain mobility by different time domain nuclear magnetic resonance (TD-NMR) techniques evidenced a population of rigid rubber chains surrounding particles, whose amount increases with the particle anisotropy, even in the absence of significant differences in terms of chemical crosslinking. Dynamic measurements demonstrate that rod-like particles induce stronger reinforcement of rubber, increasing with the AR. This was related to the self-alignment of the anisotropic silica particles in domains able to immobilize rubber. PMID:25899456

  2. Effects of aminopropyltriethoxysilane (γ-APS) on tensile properties and morphology of polypropylene (PP), recycle acrylonitrile butadiene rubber (NBRr) and sugarcane bagasse (SCB) composites

    Science.gov (United States)

    Santiagoo, Ragunathan; Omar, Latifah; Zainal, Mustaffa; Ting, Sam Sung; Ismail, Hanafi

    2015-07-01

    The performance of sugarcane baggase (SCB) treated with γ-APS filled polypropylene (PP)/recycled acrylonitrile butadiene rubber (NBRr) biocomposites were investigated. The composites with different filler loading ranging from 5 to 30 wt % were prepared using heated two roll mill by melt mixing at temperature of 180 °C. Tensile properties of the PP/NBRr/SCB composites which is tensile strength, Young Modulus and elongation at break were investigated. Increasing of treated SCB filler loading in PP/NBRr/SCB composites have increased the Young modulus however decreased the tensile strength and elongation at break of the PP/NBRr/SCB composites. From the results, γ-APS treated SCB composites shown higher tensile strength and Young Modulus but lower elongation at break when compared to the untreated SCB composites. This is due to the stronger bonding between γ-APS treated SCB with PP/NBRr matrices. These findings was supported by micrograph pictures from morphological study. SCB filler treated with γ-APS has improved the adhesion as well as gave strong interfacial bonding between SCB filler and PP/NBRr matrices which results in good tensile strength of PP/NBRr/SCB composites.

  3. Preparation and Characterization of Carboxyl-terminated Poly (butadiene-co-acrylonitrile)-epoxy Resin Prepolymers for Fusion-bonded-epoxy Powder Coating

    Institute of Scientific and Technical Information of China (English)

    LIU Jingcheng; JIA Xiuli; ZHANG Shengwen; LIU Ren; LIU Xiaoya

    2012-01-01

    Liquid carboxyl-terminated poly(butadiene-co-acrylonitrile)(CTBN)-epoxy resin(EP)prepolymers were prepared with different contents of CTBN.The chemical reactions between EP and CTBN were characterized by Fourier ransform infrared (FTIR) spectroscopy and gel permeation chromatography (GPC).The scanning electron micrograph (SEM) and dynamic mechanical analysis (DMA) of curing films showed phase separation,and the rubber particles were finely dispersed in the epoxy matrix.Mechanical properties analysis of curing films showed that impact strength and elongation at break increased significantly upon the addition of CTBN,indicating good toughness of the modified epoxy resins.Thermogravimetric analysis (TGA) showed that the incorporation of CTBN had little effect on the thermal stability of EP.Fusion-bondedepoxy (FBE) powder coatings modified with CTBN-EP prepolymers were prepared.The experimental results demonstrate the ability of CTBN-EP prepolymers,toughening technology to dramatically enhance the flexibility and impact resistance of FBE coatings without compromising other key properties such as corrosion protection.

  4. Water-responsive mechanically adaptive nanocomposites based on styrene-butadiene rubber and cellulose nanocrystals--processing matters.

    Science.gov (United States)

    Annamalai, Pratheep K; Dagnon, Koffi L; Monemian, Seyedali; Foster, E Johan; Rowan, Stuart J; Weder, Christoph

    2014-01-22

    Biomimetic, stimuli-responsive polymer nanocomposites based on a hydrophobic styrene-butadiene rubber (SBR) matrix and rigid, rod-like cellulose nanocrystals (CNCs) isolated from cotton were prepared by three different approaches, and their properties were studied and related to the composition, processing history, and exposure to water as a stimulus. The first processing approach involved mixing an aqueous SBR latex with aqueous CNC dispersions, and films were subsequently formed by solution-casting. The second method utilized the first protocol, but films were additionally compression-molded. The third method involved the formation of a CNC organogel via a solvent exchange with acetone, followed by infusing this gel, in which the CNCs form a percolating network with solutions of SBR in tetrahydrofuran. The thermomechanical properties of the materials were established by dynamic mechanical thermal analysis (DMTA). In the dry state, all nanocomposites show much higher tensile storage moduli, E', than the neat SBR or the SBR latex. E' increases with the CNC content and depends strongly on the processing method, which appears to influence the morphology of the SBR nanocomposites produced. The highest E' values were observed for the solution cast samples involving an SBR latex, where E' increased from 3 MPa for the neat SBR to ca. 740 MPa for the nanocomposite containing 20% v/v CNCs. Upon submersion in deionized water, a dramatic reduction of E' was observed, for example from 740 to 5 MPa for the solution-cast nanocomposite containing 20% v/v CNCs. This change is interpreted as a disengagement of the percolating CNC network, on account of modest aqueous swelling and competitive hydrogen bonding of water molecules with the CNCs. It is shown that the method of preparation also influenced the swelling behavior and kinetics of modulus switching, consistent with different arrangements of the CNCs, which serve as channels for water absorption and transport within the

  5. One-step Preparation and Antibacterial Property of Poly(N-iso- propyl-acrylamide) Grafted Poly(acrylonitrile/styrene) Micro- spheres Immobilized with Silver Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    FENG,Jiao; FAN,Liheng; CHU,Hong; XIONG,Wanbin; JIANG,Jinqiang; CHEN,Mingqing

    2009-01-01

    Monodispersed silver nanoparticles were immobilized onto the surface of poly(N-isopropylacrylamide) grafted poly(acrylonitrile/styrene) (PNIPAAm-g-PAN/PSt) microspheres by a one-step method using AgNO3 as a silver source. This process was performed via the coordination interaction between Ag ions and amide groups on PNIPAAm-g-PAN/PSt microsphere surfaces with the reduction of the corresponding ions by ethanol taking place simultaneously. Fourier transform infrared (FTIR) spectroscopy and ultraviolet (UV)-visible spectra illustrated that the silver nanoparticles were successfully immobilized onto the PNIPAAm-g-PAN/PSt microspheres. The size and morphology of silvered microspheres were characterized by transmission electron microscopy (TEM). The weight percent of silver nanoparticles immobilized onto the microspheres was 12% based on the determination of thermogravimetric analysis (TGA). The antibacterial tests demonstrated that the as-prepared silvered microspheres showed activity against Gram-negative bacteria.

  6. Design and Synthesis of Transparent Poly (acrylonitrile butadiene-styrene) and Relationship Between Its Phase Construction and Transparency

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A series of transparent ABS(T-ABS) resins were prepared by emulsion in situ suspension polymerization. The influences of the particle size and the content of rubber particles on the transparency of T-ABS resins were studied by varying the size and content of rubber particles in a single model system( rubber particles with a uniform size). The optical properties of T-ABS resins were investigated in a mixed system of SBR/PB particles and a bi-modal particle system(rubber particles with two different sizes, 70 and 400 nm in diameter) of SBR particles. It was found that when the size of the smaller particles (70 nm) in the mixed system of SBR/PB particles was in the range of 50-100 nm in diameter, the T-ABS resins showed a better transparency. These results provide a flexible and practical process for the preparation of T-ABS resins with good optical and mechanical properties.

  7. Effect of winding layer and speed on kenaf/glass fiber hybrid reinforced acrylonitrile butadiene styrene (ABS) composites

    Science.gov (United States)

    Khoni, Norizzahthul Ainaa Abdul; Sharifah Shahnaz S., B.; Ghazali, Che Mohd Ruzaidi

    2016-07-01

    The usage of natural fiber is becoming significant in composite industries due to their good performance. Single and continuous natural fibers have relatively high mechanical properties; especially their young modulus can be as high as glass fibers. Filament winding is a method to produce technically aligned composites which have high fibers content. The properties of filament winding can be tailored to meet the end product requirements. This research studied the compression properties of kenaf/glass fibers hybrid reinforced composites. Kenaf/glass fibers hybrid composite samples were fabricated by filament winding technique and their properties were compared with the properties of neat kenaf fiber and glass fibers composites. The kenaf/glass fiber hybrid composites exhibited higher strength compared to the neat glass fibers composites. Composites of helical pattern, which produced at low winding speed showed better compression resistance than hoop pattern winding, which produced at high winding speed. As predicted, kenaf composite showed highest water absorption; followed by kenaf/glass fiber hybrid composites while neat glass fiber has lowest water absorption capability.

  8. STUDY ON THE SEQUENCE STRUCTURE OF BUTADIENE-STYRENE RUBBER BY 13C-NMR METHOD Ⅲ. QUANTITATIVE CHARACTERIZATION OF SEQUENCE STRUCTURE

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiaonong; HU Liping; YAN Baozhen; JIAO Shuke

    1990-01-01

    The quantitative description of the sequence structure of emulsion-processed SBR and solution-processed SBR (by lithium catalyst)was carried out based on their spectral data of 13C-NMR.The calculating formulae which could be used to obtain diad concentration from the peak intensities of carbon spectra, average block length, average number of block, and the microstructure composition of the molecular chain were derived. The quantitative result showed that on the molecular chain styrene unit had the tendency to attach to trans-1,4 butadiene unit. The calculated result of the microstructure was in good agreement with that obtained through IR measurement.

  9. Methoxy Silane in Styrene-butadiene Synthetic Resin%甲氧基硅烷在丁苯合成树脂的研究

    Institute of Scientific and Technical Information of China (English)

    王平; 舒畅; 蓝晓; 钟凤清

    2012-01-01

    The star styrene-butadiene copolymerization were synthesized by using styrene and butadiene as monomers, n-BuLi as initiator, Methyl-trimethoxy-silane as coupling agent and cyclohexane as solvent by anionic polymerization. The effect of quantity of coupling agent, feed stock times, polymerization temperature and polymerization time on the coupling efficiency(CE%) and average branching number(BN) were investigated.%以苯乙烯、丁二烯为单体,N—BuLi为引发剂,环己烷为溶剂,甲基三甲氧基硅烷为偶联剂,通过负离子聚合和偶联反应,制备含有多种嵌段水平的星形r苯透明抗冲树脂。并初步探讨了偶联剂加入量、加料次数、温度、时间和基峰分子量与偶联效率、支化度(臂数)的关系。

  10. 1,3-Butadiene, styrene and lymphohematopoietic cancer among male synthetic rubber industry workers--Preliminary exposure-response analyses.

    Science.gov (United States)

    Sathiakumar, Nalini; Brill, Ilene; Leader, Mark; Delzell, Elizabeth

    2015-11-01

    We updated the mortality experience of North American synthetic rubber industry workers to include follow-up from 1944 through 2009, adding 11 years of mortality data to previous investigations. The present analysis used Cox regression to examine the exposure-response relationship between 1,3-butadiene (BD) and styrene (STY) parts per million (ppm)-years and leukemia (N = 114 deaths), non-Hodgkin lymphoma (NHL) (N = 89) and multiple myeloma (MM) (N = 48). A pattern of largely monotonically increasing rate ratios across deciles of BD ppm-years and a positive, statistically significant exposure-response trend were observed for BD ppm-years and leukemia. Using continuous, untransformed BD ppm-years the regression coefficient (β) adjusted only for age was 2.6 × 10(-4) (p race and plant was 2.9 × 10(-4) (p separate effects of these two agents could not be estimated. For NHL, a pattern of approximately monotonically increasing rate ratios across deciles of exposure was seen for STY but not for BD; the test of trend was statistically significant in one of five models that used different STY exposure metrics and adjusted for age and other covariates. BD ppm-years and STY ppm-years were not associated with MM. The present analyses indicated a positive exposure-response relationship between BD cumulative exposure and leukemia. This result along with other research and biological information support an interpretation that BD causes leukemia in humans. STY exposure also was positively associated with leukemia, but its independent effect could not be delineated because of its strong correlation with BD, and there is no external support for a STY-leukemia association. STY, but not BD, was associated positively with NHL. The interpretation of this result is uncertain because the exposure-response data were statistically imprecise and because consistent support for causality from other studies is lacking. The current study provides no support for an association

  11. Studies on the physico-mechanical and thermal characteristics of blends of DGEBA epoxy, 3,4 epoxy cyclohexylmethyl, 3',4'-epoxycylohexane carboxylate and carboxyl terminated butadiene co-acrylonitrile (CTBN)

    International Nuclear Information System (INIS)

    Toughening of blend of diglycidyl ether of bisphenol-A (DGEBA) and 3,4 epoxy cyclohexylmethyl, 3',4'-epoxycylohexane carboxylate, i.e. cycloaliphatic epoxy resin (CAE) with varying weight ratios (0-25 wt%) of carboxyl terminated butadiene acrylonitrile (CTBN) copolymer have been investigated. Fourier transform infrared (FTIR) spectroscopic analysis established that the interaction between oxirane groups of DGEBA, CAE and CTBN were responsible for characteristics peak shifts in the blends compared to their counterparts. Physico-mechanical properties of the prepared samples, e.g. tensile, flexural and impact strengths showed an optimum concentration of CTBN (15 wt%) into epoxy matrix, which offered maximum toughening. Thermal stability of the prepared samples was analyzed by dynamic thermogravimetric runs. Cross-sections of the cured samples which failed during impact testing have been critically studied through scanning electron microscopic (SEM) analysis to gain insight into the phase morphology

  12. Studies on the physico-mechanical and thermal characteristics of blends of DGEBA epoxy, 3,4 epoxy cyclohexylmethyl, 3',4'-epoxycylohexane carboxylate and carboxyl terminated butadiene co-acrylonitrile (CTBN)

    Energy Technology Data Exchange (ETDEWEB)

    Tripathi, Garima [Department of Plastic Technology, H. B. Technological Institute, Kanpur 208002 (India); Srivastava, Deepak [Department of Plastic Technology, H. B. Technological Institute, Kanpur 208002 (India)], E-mail: deepak_sri92@rediffmail.com

    2008-11-25

    Toughening of blend of diglycidyl ether of bisphenol-A (DGEBA) and 3,4 epoxy cyclohexylmethyl, 3',4'-epoxycylohexane carboxylate, i.e. cycloaliphatic epoxy resin (CAE) with varying weight ratios (0-25 wt%) of carboxyl terminated butadiene acrylonitrile (CTBN) copolymer have been investigated. Fourier transform infrared (FTIR) spectroscopic analysis established that the interaction between oxirane groups of DGEBA, CAE and CTBN were responsible for characteristics peak shifts in the blends compared to their counterparts. Physico-mechanical properties of the prepared samples, e.g. tensile, flexural and impact strengths showed an optimum concentration of CTBN (15 wt%) into epoxy matrix, which offered maximum toughening. Thermal stability of the prepared samples was analyzed by dynamic thermogravimetric runs. Cross-sections of the cured samples which failed during impact testing have been critically studied through scanning electron microscopic (SEM) analysis to gain insight into the phase morphology.

  13. 40 CFR 63.500 - Back-end process provisions-carbon disulfide limitations for styrene butadiene rubber by emulsion...

    Science.gov (United States)

    2010-07-01

    .... There shall be a standard operating procedure representing the production of every grade of styrene... or 1A of 40 CFR part 60, appendix A, as required, shall be used for selection of the sampling sites. (ii) The gas volumetric flow rate shall be determined using Method 2, 2A, 2C, or 2D of 40 CFR part...

  14. 纤维素纳米纤维-丁苯胶乳复合材料的制备与表征%Preparation and characterization of cellulose-nanoifbers/styrene-butadiene latex (NFs/SBL) composites

    Institute of Scientific and Technical Information of China (English)

    宋冰; 石勇; 陆海龙; 马金霞; 周小凡

    2016-01-01

    采用共混法制备不同纤维素纳米纤维含量的纤维素纳米纤维-丁苯胶乳复合材料,并通过拉伸性能、扫描电镜、热重分析以及红外光谱检测该复合材料的相关性能。分析结果表明:纤维素纳米纤维能均匀分散在丁苯胶乳溶液中,对丁苯胶乳有较好的补强效果;和丁苯胶乳相比,制得复合材料的裂断伸长率增大,弹性变好;但纤维素纳米纤维的加入对丁苯胶乳热稳定性的影响不明显。%Cellulose-nanofibers/styrene-butadiene latex(NFs-SBL) composites were prepared by blending different amount of cellulose nanofibers with styrene-butadiene latex(SBL), through the tensile properties testing, scanning electron microscopy (SEM), thermo-gravimetric analysis and infrared spectrometric analysis(FT-IR). The result showed that NFs are dispersed uniformly in styrene-butadiene latex and showed a good reinforcing effect on SBL, composite material breaking elongation increased and elastic becoming good. However, the addition of NFs had a less impact on thermal stability of styrene-butadiene latex.

  15. Utilizing carbon dioxide as a reaction medium to mitigate production of polycyclic aromatic hydrocarbons from the thermal decomposition of styrene butadiene rubber.

    Science.gov (United States)

    Kwon, Eilhann E; Yi, Haakrho; Castaldi, Marco J

    2012-10-01

    The CO(2) cofeed impact on the pyrolysis of styrene butadiene rubber (SBR) was investigated using thermogravimetric analysis (TGA) coupled to online gas chromatography/mass spectroscopy (GC/MS). The direct comparison of the chemical species evolved from the thermal degradation of SBR in N(2) and CO(2) led to a preliminary mechanistic understanding of the formation and relationship of light hydrocarbons (C(1-4)), aromatic derivatives, and polycyclic aromatic hydrocarbons (PAHs), clarifying the role of CO(2) in the thermal degradation of SBR. The identification and quantification of over 50 major and minor chemical species from hydrogen and benzo[ghi]perylene were carried out experimentally in the temperature regime between 300 and 500 °C in N(2) and CO(2). The significant amounts of benzene derivatives from the direct bond dissociation of the backbone of SBR, induced by thermal degradation, provided favorable conditions for PAHs by the gas-phase addition reaction at a relatively low temperature compared to that with conventional fuels such as coal and petroleum-derived fuels. However, the formation of PAHs in a CO(2) atmosphere was decreased considerably (i.e., ∼50%) by the enhanced thermal cracking behavior, and the ultimate fates of these species were determined by different pathways in CO(2) and N(2) atmospheres. Consequently, this work has provided a new approach to mitigate PAHs by utilizing CO(2) as a reaction medium in thermochemical processes. PMID:22950720

  16. The use of styrene-butadiene rubber waste as a potential filler in nitrile rubber: order of addition and size of waste particles

    Directory of Open Access Journals (Sweden)

    D. A. Baeta

    2009-03-01

    Full Text Available Styrene-butadiene rubber (SBR has large applications in the shoe industry, especially as expanded sheets used to produce insoles and inner soles. According to TG analysis, the rubber content in SBR residues (SBR-r was found to be around 26-wt%. Based on that data, a cost-effective technique for the reuse of SBR-r in Nitrile rubber (NBR was developed. Later, the effect of SBR-r on the cure behavior, mechanical performance, swelling, and crosslink density of reused rubber was investigated, with more emphasis placed on the effect of both particle size and loading of waste filler. Cure characteristics such as optimum cure time and scorch time were then reduced by the increasing amount of SBR-r filler. Owing to the reinforced nature of the largest particle size SBR-r, the best results for the mechanical properties of NBR were those in which SBR-r was added at the end of the cure process. The study has thus shown that SBR residue (SBR-r can be used as an economical alternative filler in NBR.

  17. Adhesion properties of styrene-butadiene rubber (SBR/Standard Malaysian Rubber (SMR L-based adhesives in the presence of phenol formaldehyde resin

    Directory of Open Access Journals (Sweden)

    2007-10-01

    Full Text Available The adhesion properties, i. e. viscosity, tack and peel strength of styrene-butadiene rubber (SBR/Standard Malaysian Rubber (SMR L-based pressure-sensitive adhesive was studied using phenol formaldehyde resin as the tackifying resin. Toluene was used as the solvent throughout the experiment. SBR composition in SBR/SMR L blend used was 0, 20, 40, 60, 80, 100%. Three different resin loadings, i. e. 40, 80 and 120 parts per hundred parts of rubber (phr were used in the adhesive formulation. The viscosity of adhesive was determined by a HAAKE Rotary Viscometer whereas loop tack and peel strength of paper/polyethylene terephthalate (PET film were measured using a Lloyd Adhesion Tester operating at 30 cm/min. Results indicate that the viscosity of adhesive decreases with increasing % SBR whereas loop tack passes through a maximum value at 20% SBR for all resin loadings. Except for the control sample (without resin, the peel strength shows a maximum value at 60% SBR for the three modes of peel tests. For a fixed % SBR, adhesive sample containing 40 phr phenol formaldehyde resin always exhibits the highest loop tack and peel strength, an observation which is associated to the optimum wettability of adhesive on the substrate.

  18. Water soluble styrene butadiene rubber and sodium carboxyl methyl cellulose binder for ZnFe2O4 anode electrodes in lithium ion batteries

    Science.gov (United States)

    Zhang, Rongyu; Yang, Xu; Zhang, Dong; Qiu, Hailong; Fu, Qiang; Na, Hui; Guo, Zhendong; Du, Fei; Chen, Gang; Wei, Yingjin

    2015-07-01

    ZnFe2O4 nano particles as an anode material for lithium ion batteries are prepared by the glycine-nitrate combustion method. The mixture of styrene butadiene rubber and sodium carboxyl methyl cellulose (SBR/CMC) with the weight ratio of 1:1 is used as the binder for ZnFe2O4 electrode. Compared with the conventional polyvinylidene-fluoride (PVDF) binder, the SBR/CMC binder is much cheaper and environment benign. More significantly, this water soluble binder significantly improves the rate capability and cycle stability of ZnFe2O4. A discharge capacity of 873.8 mAh g-1 is obtained after 100 cycles at the 0.1C rate, with a very little capacity fading rate of 0.06% per cycle. Studies show that the SBR/CMC binder enhances the adhesion of the electrode film to the current collector, and constructs an effective three-dimensional network for electrons transport. In addition, the SBR/CMC binder helps to form a uniform SEI film thus prohibiting the formation of lithium dendrite. Electrochemical impedance spectroscopy shows that the SBR/CMC binder lowers the ohmic resistance of the electrode, depresses the formation of SEI film and facilitates the charge transfer reactions at the electrode/electrolyte interface. These advantages highlight the potential applications of SBR/CMC binder in lithium ion batteries.

  19. Application of solution polymerized styrene-butadiene rubber 2557-A in tire%溶聚丁苯橡胶2557-A在轮胎中的应用

    Institute of Scientific and Technical Information of China (English)

    徐燕; 孙举涛; 徐文清; 张萍; 孙学红

    2012-01-01

    In accordance with the pure carbon black formula, solution polymerized styrene-butadiene rubber ( SSBR, grade 2557-A) and emulsion styrene-butadiene rubber(ESBR, grade 1712) were applied to crown rubbers of all-steel and semi-steel radial tires seperately, their application results were compared, and the acceptable crown rubber formula of SSBR 2557-A was achieved. The all-steel and semi-steel radial tires were trial-produced, and their performances were tested. The results showed that compared to ESBR 1712 all-ateel crown vulcanizate. The tensile strength, modulus at 100% and 300% , abrasion resistance ( Akron) , compression heat built-up as well as the balance between wet skid resistance and rolling resistance of the equivalent SSBR 2557-A crown vulcani- zate increased, but abrasion resistance ( DIN ) decreased- And compared to ESBR 1712 semi-stell crown vulcanizate, the equivalent SSBR 2557-A also improved semi-steel crown vulcanizate in skid resistance without changing any other performances. The trial tire based on SSBR 2557-A all-steel crown rubber formula passed endurance test, and the tire based on SSBR 2557-A semi-steel crown rubber formula met the national standard in outer dia, strength, unseating resistance, highspeed performance and durability, in addition, it had substantial high wet skid resistance and noise performance.%按照纯炭黑配方,将溶聚丁苯橡胶(SSBR,牌号为2557 -A)同乳聚丁苯橡胶(ESBR,牌号为1712)对比应用于全钢和半钢子午线轮胎胎冠胶配方中,确定了合适的胎冠胶配方,且进行了轮胎的试制和性能检测.结果表明,与ESBR 1712全钢胎冠胶相比,同等用量SSBR 2557 -A的胎冠胶拉伸强度、定伸应力、Akron磨耗性能和压缩生热等性能均得到提高,但DIN磨耗性能有所下降,且具有更优的抗湿滑性和更低的滚动阻力;与ESBR 1712半钢胎冠胶相比,SSBR 2557 -A胎冠胶具有优异的抗湿滑性能,而其他性能相差不大;采用SSBR 2557 -A

  20. Transport characteristics of organic solvents through carbon nanotube filled styrene butadiene rubber nanocomposites: the influence of rubber-filler interaction, the degree of reinforcement and morphology.

    Science.gov (United States)

    Abraham, Jiji; Maria, Hanna J; George, Soney C; Kalarikkal, Nandakumar; Thomas, Sabu

    2015-05-01

    The transport behaviour of some aromatic and aliphatic solvents through carbon nanotube filled styrene butadiene rubber composites has been investigated. The aim of the present work is to investigate the role of the sorption technique in analysing the compatibility and the reinforcing effect of MWCNTs as a filler in the SBR matrix. It also focuses on the investigation of the relationship between the dispersion of CNTs in the SBR matrix and its transport behaviour. The diffusion and transport of organic solvents through the membranes have been investigated in detail as a function of CNT content, nature of solvent and temperature in the range of 28-60 °C. Solvent uptake, diffusion, sorption and permeation constants were investigated and were found to decrease with the increase of CNT loading. Transport properties could be related to the morphology of the nanocomposites. At high concentration CNT particles form a local filler-filler network in the rubber matrix. As a result, the transport of solvent molecules through the polymer is hindered. The rubber-solvent interaction parameter, enthalpy and entropy of sorption have also been estimated from the transport data. The values of rubber-solvent interaction parameters obtained from the diffusion experiments have been used to calculate the molecular mass between the crosslinks of the network polymer. The better reinforcement at higher filler loading was confirmed from the cross-link density values. The extent of reinforcement was evaluated using Kraus and Cunneen and Russel equations. The Affine and Phantom models for chemical crosslinks were used to predict the mobility of the crosslinks. The Phantom model gave better fitting indicating that the chains can move freely through one another, i.e. the junction points fluctuate over time around their mean position without any hindrance from the neighbouring molecule. The diffusivity datas of the systems have shown dependence on the temperature and microstructure of the

  1. Synthesis and characterization of poly(styrene-co-methyl methacrylate); Sintese e caracterizacao do poli(estireno-co-metacrilato de metila)

    Energy Technology Data Exchange (ETDEWEB)

    Augustinho, Tiago R.; Abarca, Silvia A.C.; Machado, Ricardo A.F. [Departamento de Engenharia Quimica e Alimentos - Universidade Federal de Santa Catarina - UFSC, Florianopolis, SC (Brazil)

    2011-07-01

    Polystyrene (PS) is nowadays commonly used due its advantages over competitors. PS presents a lower cost when compared with Acrylonitrile Butadiene Styrene (ABS) and with Polyethylene Tere-phthalate (PET), and can be easier processed than polypropylene (PP). At expandable form (EPS), can be used as projective equipment, thermal insulation, floating boards, refrigerators, isothermal, and low cost applications such as packaging and disposable material. Searching for more resistant materials and with a low cost, researches with copolymers materials are being developed. In this study, copolymerization reactions were carried out by suspension polymerization using monomers styrene and methyl methacrylate (MMA) with styrene. Styrene was in the highest percentage in relation to the MMA. The MMA was selected because is a monomer that presents a higher resistance than PS. The copolymerization was confirmed by performing infrared spectroscopy (IR), nuclear magnetic resonance of hydrogen (RMN{sup 1}H), differential scanning calorimetry (DSC) and thermogravimetry (TGA). (author)

  2. Determination of Bound Acrylonitrile Content in Acrylonitrile-butadiene Rubber(NBR) by Infrared Spectroscopy Method%红外光谱法测定丁腈橡胶中的结合丙烯腈含量

    Institute of Scientific and Technical Information of China (English)

    高杜娟; 黄世英; 赵家琳; 刘俊保

    2015-01-01

    Infrared spectrometry in this article was used to determinate the bound acrylonitrile content in nitrile rubber( NBR). In the process of experimenting,the sample preparation conditions were determined and the stand-ard values of seven substitute standard sample were confirmed by Kjeldahl method,through which the quantitative calculation formula was get. And finally,the results were compared with the method of element analysis.%本文采用红外光谱法测定丁腈橡胶( NBR)中的结合丙烯腈含量,确定了样品前处理条件,通过凯氏定氮法确定7个代用标准胶中结合丙烯腈含量的标准值,得出了结合丙烯腈含量的定量计算公式,测试结果与元素分析法进行了对比。

  3. Treatment Process Transformation of Wastewater From Styrene Butadiene Rubber Production%丁苯橡胶生产废水整改的必要性及工艺路线

    Institute of Scientific and Technical Information of China (English)

    胡雍; 刘伟; 高勇

    2014-01-01

    The properties of wastewater from styrene butadiene rubber production were discussed as well as its influence on operation of wastewater treatment unit; the pilot of wastewater treatment and comparison of the water quality data were carried out by using a variety of techniques, the suitable process route for treating styrene butadiene rubber production wastewater was determined, the pretreated water can meet the biochemical system of sewage plant.%论述了某化工厂丁苯橡胶生产废水的特性及对厂区污水处理场运行的影响;通过采用各种工艺技术对该废水进行小试并对水质数据比对,得出适合丁苯橡胶生产废水改造的工艺路线,使经预处理后的水质不会对污水处理场生化系统造成冲击。

  4. 丙烯腈-苯乙烯磺酸共聚物/层状双金属氢氧化物纳米复合质子传导聚合物电解质的制备与表征%Synthesis and characterization of proton-conducting polymer electrolytes based on acrylonitrile-styrene sulfonic acid copolymer/layered double hydroxides nanocomposites

    Institute of Scientific and Technical Information of China (English)

    王盎然; 包永忠; 翁志学; 黄志明

    2008-01-01

    Acrylonitrile-sodium styrene sulfonate copolymer/layered double hydroxides nanocomposites were prepared by in situ aqueous precipitation copolymerization of acrylonitrile (AN) and sodium styrene sulfonate (SSS) in the presence of 4-vinylbenzene sulfonate intercalated layered double hydroxides (MgAl-VBS LDHs) and transferred to acrylonitrile-styrene sulfonic acid (AN-SSA) copolymer/LDHs nanocomposites as a proton-conducting polymer electrolyte. MgAl-VBS LDHs were prepared by a coprecipitation method, and the structure and composition of MgAl-VBS LDHs were determined by X-ray diffraction (XRD), infrared spectroscopy, and elemental analysis. X-ray diffraction result of AN-SSS copolymer/LDHs nanocomposites indicated that the LDHs layers were well dispersed in the AN-SSS copolymer matrix. All the AN-SSS copolymer/LDHs nanocomposites showed significant enhancement of the decomposition temperatures compared with the pristine AN-SSS copolymer, as identified by the thermogravimetric analysis. The methanol crossover was decreased and the proton conductivity was highly enhanced for the AN-SSA copolymer/LDHs nanocomposite electrolyte systems In the case of the nanocomposite electrolyte containing 2% (by mass) LDHs, the proton conductivity of 2.60×10-3 S·m-1 was achieved for the polymer electrolyte.

  5. 乳聚丁苯橡胶后处理工艺技术改进%Technology improvement in post-processing unit of emulsion polymerization styrene butadiene rubber production

    Institute of Scientific and Technical Information of China (English)

    李愿鹏

    2012-01-01

    乳聚丁苯橡胶生产中,后处理单元是决定产品质量的关键环节.针对后处理单元非计划停车频繁、运行周期短的状况,从工艺、设备、现场管理等方面进行了分析,找出影响后处理单元稳定运行的主要因素并进行了改进.%The post-processing unit is the key link to the quality of products in the emulsion polymerization styrene butadiene rubber production. According to the condition of the frequent unplanned shutdowns and short cycle operation status, the a-nalysis is carried out from technology, equipment, site management, etc. The main factors influencing the stable operation of post-processing unit are found out and improved,

  6. Inlfuence of Different Toughness Agents on Weatherability of Acrylonitrile-Styrene Copolymer%不同增韧剂对丙烯腈-苯乙烯共聚物耐候性的影响

    Institute of Scientific and Technical Information of China (English)

    贺芳; 黄兴宇; 钱晶; 申娟

    2015-01-01

    Using seven different toughness agents in acrylonitrile-styrene copolymer(SAN Resin)was studied,the influence of high glue powder,acrylic resin(ACR),maleic anhydride grafted EPDM (EPDM–g–MAH),styrene copolymer(MBS),ethylene butyl acrylate(EBA),maleic anhydride grafted PE–LD(PE–LD–g–MAH)and ethylene methyl acrylate(EMA) on mechanical properties of acrylonitrile styrene copolymer(SAN resin)was respectively researched. And temperature test machine and xenon lamp climate chamber were used to analysis of the influence of different toughness agents on the weatherability of SAN. The results show that compared with other toughness agents,the impact strength of SAN resin with MBS is the best. The impact strength of SAN resin is decreasing with the lower temperature,EBA and EPDM–g–MAH could improve the impact strength of SAN resin in low temperature. And Xenon lamp aging test results show that the SAN resin will appear the phenomenon of xanthochroia after xenon lamp aging test,but EPDM–g–MAH,MBS and EBA could improve the light resistance properties of SAN resin,and the effect of EPDM–g–MAH is the best.%采用7种增韧剂:高胶粉、丙烯酸酯类树脂(ACR),马来酸酐接枝三元乙丙橡胶(EPDM–g–MAH),苯乙烯三元共聚物(MBS),乙烯丙烯酸丁酯(EBA),马来酸酐接枝低密度聚乙烯(PE–LD–g–MAH),乙烯–甲基丙烯酸酯(EMA)对丙烯腈-苯乙烯共聚物(SAN)进行增韧改性,通过高低温实验箱和氙灯人工气候试验箱来研究各增韧剂对SAN耐候性的影响。结果表明,添加增韧剂MBS的SAN冲击强度最高;随着温度的降低,SAN的冲击强度是下降的, EBA,EPDM–g–MAH能改善SAN的低温冲击强度;氙灯光照老化试验结果表明,SAN经过光照老化后都会出现黄变现象,而添加了EPDM–g–MAH,MBS,EBA的SAN的耐光照老化性能都有所提高,其中添加了EPDM–g–MAH的耐光照老化性最好。

  7. CASE-COHORT STUDY OF STYRENE EXPOSURE AND ISCHEMIC HEART DISEASE INVESTIGATORS

    Science.gov (United States)

    Investigators examined workers exposed to styrene while working in styrene-butadiene polymer manufacturing plants between 1943 and 1982. Workers who had died from ischemic heart disease were compared to a subgroup of all men employed in two styrene-butadiene polymer manufac...

  8. Morphology and contact angle studies of poly(styrene-co-acrylonitrile modified epoxy resin blends and their glass fibre reinforced composites

    Directory of Open Access Journals (Sweden)

    2007-06-01

    Full Text Available In this study, the surface characteristics of blends and composites of epoxy resin were investigated. Poly(styrene-co-acylonitrile (SAN was used to modify diglycedyl ether of bisphenol-A (DGEBA type epoxy resin cured with diamino diphenyl sulfone (DDS and the modified epoxy resin was used as the matrix for fibre reinforced composites (FRP’s. E-glass fibre was used as the fibre reinforcement. The scanning electron micrographs of the fractured surfaces of the blends and composites were analyzed. Morphological analysis revealed different morphologies such as dispersed, cocontinuous and phase-inverted structures for the blends. Contact angle studies were carried out using water and methylene iodide at room temperature. The solid surface energy was calculated using harmonic mean equations. Blending of epoxy resin increases its contact angle. The surface free energy, work of adhesion, interfacial free energy, spreading coefficient and Girifalco-Good’s interaction parameter were changed significantly in the case of blends and composites. The incorporation of thermoplastic and glass fibre reduces the wetting and hydrophilicity of epoxy resin.

  9. Scientific Opinion on the safety assessment of the substances (butadiene, ethyl acrylate, methyl methacrylate, styrene copolymer either not crosslinked or crosslinked with divinylbenzene or 1,3-butanediol dimethacrylate, in nanoform, for use in food contact materials

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF

    2014-04-01

    Full Text Available This scientific opinion of the EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids deals with the safety assessment of the additives (butadiene, ethyl acrylate, methyl methacrylate, styrene copolymer either not crosslinked or crosslinked with divinylbenzene or 1,3-butanediol dimethacrylate, in nanoform, (FCM substance Nos 998, 859 and 1043, intended to be used up to 10 % w/w as an impact modifier in rigid (unplasticized polyvinylchloride (PVC. The final material is intended to be used for contact with all food types, at room temperature or lower, for long time storage. The monomers constituting the copolymer are listed in Regulation (EU 10/2011. The migration from PVC of the low molecular weight fraction of the additive below 1000 Da was estimated to be about 0.009 mg/kg food. Considering that these low molecular weight oligomers are made from authorised monomers, which by reaction are expected to lack the reactive functional groups, they do not give rise to safety concern. The migration of the additive in nanoparticle form from the PVC was estimated, using conservative migration modelling, to be about 1 x 10-6 mg/kg food and so consumer exposure would be very low, if any. The CEF Panel concluded that there is no safety concern for the consumer if the substances are used as additives individually or in combination at up to a total of 10 % w/w in rigid PVC used in contact with all food types at ambient temperature or below including long-term storage.

  10. Structure and Properties of Clay/Butadiene-Styrene-Vinyl Pyridine Rubber Nanocomposites%粘土/丁吡橡胶纳米复合材料的结构与性能研究

    Institute of Scientific and Technical Information of China (English)

    何少剑; 王益庆; 张立群

    2013-01-01

    The clay/butadiene-styrene-vinyl pyridine rubber nanocomposites were prepared by latex compounding method,and their structure and properties were investigated. The results showed that,the dispersion of clay in the nanocomposites was good,and the addition level of clay affected the structure of the nanocomposites. As the addition level of clay increased, the storage modulus of the mixed compound and vulcanizate increased gradually, the loss factor of vulcanizate increased as the strain increased,the Shore A hardness and modulus at 100% elongation increased gradually,and the air tightness was improved. The nanocomposites showed the best tensile properties when the addition level of clay was 20 phr.%采用乳液共沉法制备粘土/丁吡橡胶纳米复合材料,并对其结构和性能进行研究.结果表明:粘土/丁吡橡胶纳米复合材料的整体分散效果较好,粘土用量对纳米复合材料的类型有影响;随着粘土用量的增大,粘土/丁吡橡胶混炼胶和硫化胶的储能模量逐渐增大,硫化胶的损耗因子随应变的增大而增大,邵尔A型硬度和100%定伸应力逐渐增大,气密性能提高;当粘土用量为20份时,复合材料的拉伸性能最佳.

  11. Caraterização composicional do AES - um copolímero de enxertia de poli(estireno-co-acrilonitrila em poli(etileno-co-propileno-co-dieno Compositional characterization of AES a graft copolymer based on poly(styrene-co-acrylonitrile and poly(etyhlene-co-propylene-co-diene

    Directory of Open Access Journals (Sweden)

    Renato Turchet

    2006-06-01

    Full Text Available O objetivo deste trabalho é a caracterização do AES, um copolímero de enxertia de poli(estireno-co-acrilonitrila, SAN, em poli(etileno-co-propileno-co-dieno, EPDM. Para tanto, o AES foi submetido à extração seletiva de seus componentes: o SAN livre, o EDPM livre, e o copolímero de enxertia EPDM-g-SAN. O AES e suas frações foram caracterizados por espectroscopia de infravermelho, análise elementar, calorimetria diferencial de varredura e ressonância magnética nuclear, RMN¹H e RMN13C. O AES analisado apresenta a seguinte composição em massa: 65% de EPDM-g-SAN, 13% de EPDM livre e 22% de SAN livre. O EPDM apresenta 69,8% em massa de etileno, 26,5% em massa de propileno e 4,6% em massa do dieno, 2-etilideno-5-norboneno, ENB. O SAN apresenta razão em massa acrilonitrila/estireno de 28/72 e distribuição randômica de comonômeros de estireno e acrilonitrila. Estes resultados são concordantes com a composição do AES fornecida pelo fabricante, indicando que a metodologia proposta é adequada.This work aims the characterization of AES, a graft copolymer based on poly(styrene-co-acrylonitrile, SAN, and poly(etyhlene-co-propylene-co-diene, EPDM. AES was submitted to selective extraction of its components: free SAN, EPDM chains and the graft copolymer EPDM-g-SAN. AES and its fractions were characterized by infrared spectroscopy, elemental analysis, differential scanning calorimetry, 13C and ¹H nuclear magnetic resonance. The AES has 65 wt % of EPDM-g-SAN, 13 wt % of free EPDM and 22 wt % of free SAN. EPDM has 69.8 wt % of ethylene, 26.5 wt % of propylene and 4.6 wt % of diene, 2-ethylidene-5-norbonene ENB. SAN presents acrylonitrile/styrene mass ratio of 28/72 and a random distribution of acrylonitrile and styrene comonomers. These results are in agreement with the composition reported by the AES supplier, indicating that the proposed methodology is adequate.

  12. Polybenzoxazole-filled nitrile butadiene rubber compositions

    Science.gov (United States)

    Gajiwala, Himansu M. (Inventor); Guillot, David G. (Inventor)

    2008-01-01

    An insulation composition that comprises at least one nitrile butadiene rubber (NBR) having an acrylonitrile content that ranges from approximately 26% by weight to approximately 35% by weight and polybenzoxazole (PBO) fibers. The NBR may be a copolymer of acrylonitrile and butadiene and may be present in the insulation composition in a range of from approximately 45% by weight to approximately 56% by weight of a total weight of the insulation composition. The PBO fibers may be present in a range of from approximately 3% by weight to approximately 10% by weight of a total weight of the insulation composition. A rocket motor including the insulation composition and a method of insulating a rocket motor are also disclosed.

  13. Desempenho físico-químico e mecânico de concreto de cimento Portland com borracha de estireno-butadieno reciclada de pneus Physicochemical and mechanical performance of portland cement concrete with recycled styrene-butadiene tyre-rubber waste

    Directory of Open Access Journals (Sweden)

    Camila Freitas

    2009-01-01

    Full Text Available Physicochemical and mechanical techniques were carried out to characterize three concrete tyre-rubber waste dosages such as 5, 10 and 15%, w/w. The elastomeric material was identified as styrene-butadiene rubber (SBR. It was observed that the growing SBR content in the mixture decreased the concrete performance. The best results were presented by 5% w/w tyre-rubber waste concrete sample. This composition was tested at Mourão hydroelectric powerplant spillway as repairing material.

  14. Synthesis of star-shaped solution-polymerized styrene-butadiene rubber using 1,1-diphenylhexyllithium%1,1-二苯基己基锂合成星形溶聚丁苯橡胶

    Institute of Scientific and Technical Information of China (English)

    陈波; 穆春雨; 白玉; 徐利民; 赵素合; 张兴英

    2011-01-01

    1,1 -diphenylhexyllithium ( DPHL) was prepared by the addition reaction of n-butyllithium ( n-BuLi) and 1,1 -diphenylethlene ( DPE) , with cyclohexane as solvent, and the factors affecting the yield, stability and initial activity of the product were studied. Linear-shaped solution-polymerized styrene-butadiene rubber (SSBR) was synthesized by ionic polymerization with DPHL as initiator, cyclohexane as solvent, and tetrahydrofuran (THF) as polar regulator. Star-shaped SSBR was subsequently prepared by a coupling reaction, using SnCl4 as the coupling agent. The coupling efficiency was measured. The effects of varying the structure of the chain ends, reaction time, and amount of SnCl4 on the coupling efficiency and the properties of the resulting SSBR were investigated. The results showed that the yield and purity of the DPHL were maximimized when n(DPE)/n(n-BuLi) was 1, the concentration decreased to below 90% of the original value if it was kept over 30 days at 2 t , and the diphenylalkyl group introduced by the initiator was present at the chain end of the polymers. The coupling efficiency was the highest when using the following reaction conditions; a molecular weight of 7. 0 × 104, reaction time of 60 min, and n( Cl- )/n(Li+ ) of 1. 12; it could be increased further by converting the chain ends to butadiene. Compared with that obtained using n-BuLi as an initiator, the star-shaped SSBR initiated by DPHL possessed higher tensile strength, tear strength and elongation at break, lower compression temperature rise, higher tan5 at 0 ℃ and lower tanδ at 60 ℃ .%以环己烷为溶剂,1,1-二苯基乙烯(DPE)与正丁基锂(n-BuLi)反应得到1,1-二苯基己基锂(DPHL),对其产率、稳定性和引发活性进行了研究.然后以DPHL为引发剂,四氢呋喃为结构调节剂,采用负离子聚合方法合成了线形溶聚丁苯橡胶(SSBR);最后以SnC14偶联制备星形SSBR.用凝胶渗透色谱仪、核磁共振对产物进行了表征,考查了端基结

  15. Properties of a new thermoplastic elastomer-sulfonated styrene-butadiene rubber ionomers and their blends%热塑性橡胶——磺化丁苯橡胶离聚体的性能及其共混

    Institute of Scientific and Technical Information of China (English)

    敖枝平; 谢洪泉

    2001-01-01

    丁苯橡胶(SBR)作为高不饱和度的橡胶被成功地用硫酸乙酸酐作为磺化剂在石油醚及丁酮混合溶剂配成的浓溶液中磺化,并用乙酸盐中和成离聚体。研究了离聚体及其他聚合物的共混物的熔融流动性及力学性能。结果表明,SBR离聚体能很容易在硬脂酸锌存在下熔融加工,其行为象热塑性橡胶,硬脂酸锌能降低布拉本特(Brabender)混和机的扭矩所表示的熔融粘度,并增加流动活化能和离聚体的拉伸强度。离聚体的磺酸基含量能增加熔融粘度及拉伸强度。用于中和的阳离子的种类明显地影响离聚体的性能。离聚体与聚丙烯或SBS的共混物在拉伸强度上表现出协同效应,而它与聚苯乙烯或顺-1,4聚丁二烯则呈现抵消效应。%Styrene-butadiene rubber(SBR)synthesized from emulsion polymerization was sulfonated successfully by sulfuric acid and acetic anhydride in a mixed solvent of petroleum ether and methy ethyl ketone at high concentration and neutralized with metallic acetate to form ionomer.Melt flow and mechanical properties of the ionomers and of their blends with polypropylene,SBS,polystyrene or cis-1,4 polybutadiene were studied.

  16. Solubility parameter of poly(styrene-b-butadiene-b-styrene)

    Science.gov (United States)

    Wohlfarth, Ch.

    This document is part of Subvolume D2 'Polymer Solutions - Physical Properties and their Relations I (Thermodynamic Properties: PVT -Data and miscellaneous Properties of polymer Solutions) of Volume 6 `Polymers' of Landolt-Börnstein - Group VIII `Advanced Materials and Technologies'.

  17. Preparation of Activated Nano-sized Kaolin Clay as Styrene Butadiene Rubber Filler%应用于橡胶补强的活性纳米高岭土制备

    Institute of Scientific and Technical Information of China (English)

    杜艳艳; 王燕民; 潘志东

    2013-01-01

    An activated nano-sized kaolin clay was prepared via an effective process with various methods such as chemical pre-intercalation, ultra-fine grinding, acid etching, drying and surface modification with cetyltrimethyl ammonium bromide (CTAB) and hydrogen silicone. The results show that the micron-sized kaolin clay that is pre-intercalated with urea is ground in a high-eneigy density stirred bead mill to prepare the nano-sized particles with the fineness of 70% < 100 nm and the lamella thickness of 10-30 nm effectively. This hybrid method could reduce the energy consumption in the preparation of the nano-sized kaolin clay, compared to the single ultra-fine grinding method. The acid etching treatment increased the specific surface area of the activated nano-sized kaolin clay without the destruction of the layered structure. The particles coated with CTAB and hydrogen silicone oil appeared a superior hydrophobicity. The azeotropic distillation drying could produce the well-dispersive activated nano-sized kaolin clay, compared to the spray drying. In addition, the as-prepared activated nano-sized kaolin clay could be used as a styrene butadiene rubber filler to improve the tensile strength and rate, and reduce the vulcanizing time.%采用化学插层-超细研磨-酸侵渍活化-干燥-表面改性的方法有效地制备了活性纳米高岭土.结果表明:通过化学插层与超细研磨的复合方法可制备70%的颗粒小于100 nm的高岭土,其片厚为10~30 nm.与单纯采用机械研磨的方法相比,该复合方法可以降低超细研磨所需的能耗.经酸侵渍活化处理可增大活性纳米高岭土的比表面积,但未破坏高岭土特有的层状结构.在活性纳米高岭土表面包覆十六烷基三甲基溴化铵和含氢硅油,可使其具有良好的亲油疏水性能.另外,对比喷雾干燥方法,经共沸蒸馏干燥的活性纳米高岭土粉体具有更好的分散性,制得的活性纳米高岭土作

  18. Interlaboratories Comparison of Analysis Data of Styrene Butadiene Rubber(SBR)1502 and Result Analysis%苯乙烯-丁二烯橡胶(SBR)1502实验室间数据比对结果分析

    Institute of Scientific and Technical Information of China (English)

    曹帅英; 魏玉丽; 汤妍雯; 刘俊保; 吴毅

    2013-01-01

    Rules for Proficiency Testing(CNAS-RL02:2007)explicitly stipulates that laboratories to apply for accreditation and accredited laboratories must demonstrate their testing ability in its field, it is the only way to join series of quality activities including ability validation, measurement and verification, comparison data with authorities. National accredited laboratories in the synthetic rubber industry are less, so it is more difficult to organize activities of proficiency testing. In order to satisfy the requirements of production enterprises and related laboratories in synthetic rubber industry, national quality supervision and inspection center of synthetic rubber organized interlaboratories comparison of analysis data of styrene butadiene rubber ( SBR ) 1502, statistics and analysis of comparison results were carried out by robust statistical technique, and all laboratories represented the industrial test level. The measurement results of raw rubber Mooney viscosity, ash, mix Mooney viscosity, tensile modulus at 300%in 50 min were ideal, but measurement results of volatile matter, tensile modulus at 300%in 25 min and 35 min, tensile strength and elongation at break in 35 min showed many problems, two or more laboratories appeared questionable values or outliers, part of the laboratories lacked the ability of chemical analysis and testing. Therefore, the related training content should be strengthen, the experimental instruments should be added,the interlaboratories comparison should be actively carried out.%  《能力验证规则》CNAS-RL02:2007中明确规定,申请认可的实验室和已经通过认可的实验室要证明其在该领域具有的检验能力,参加能力验证、测量审核、与权威机构比对以及多家实验室间数据比对等系列质量活动是必经之路。在合成橡胶行业通过国家认可实验室较少,组织能力验证活动比较困难,为了满足合成橡胶行业有关生产企业及相关实

  19. Effects of different cations on properties of ionomers of maleated styrene-butadiene-styrene triblock copolymer%阳离子对顺酐化苯乙烯-丁二烯-苯乙烯三嵌段共聚物离聚体性能的影响

    Institute of Scientific and Technical Information of China (English)

    刘大刚; 谢洪泉; 高玉

    2011-01-01

    The ionomers containing different cations, such as sodium, lithium, potassium, calcium,zinc, lead, magnesium, and ethyl ammonium were synthesized from the ionization of maleated styrenebutadiene-styrene triblock copolymer ( SBS ) .Effects of different cations on the thermal, mechanical, oil resistance and adhesive properties of the ionomers were studied. The results showed that, in addition to the glass transition temperatures (Tg) of butadiene and styrene blocks, the ionomers exhibited third Tg, which is due to the dissociation of the ionic domains. For the monovalent alkali metal cation neutralized ionomers, the higher the ionic potential, the higher the dissociation temperature of ionic domains, tensile strength and lap shear strength to iron plates and the order from large to small was Li+ > Na+> K+; for the divalent cation neutralized ionomers, the dissociation temperature of ionic domains decreased in the order of Ca2+> Zn2+>Pb2+ , whereas the tensile strength decreased in the order of Ca2+> Zn2 + > Mg2 + , but all were lower than those of the monovalent alkali metal cation neutralized ionomers. The oil resistance of the divalent cation neutralized ionomers was better than that of the monovalent cation neutralized ionomers or SBS.The lap shear strength of zinc ion neutralized ionomer to iron plates was the highest of all, being 0. 594 MPa.%将顺酐化苯乙烯-丁二烯-苯乙烯三嵌段共聚物(SBS)离子化得到含不同阳离子的离聚体,考察了不同阳离子对离聚体热性能、物理机械性能、耐油性能和粘接性能的影响.结果表明,离聚体有3个玻璃化转变温度(Tg),其中2个是SBS固有的Tg,另一个是离子微区的离解温度;对于含1价阳离子的离聚体,离子电离势越高,离聚体的离解温度、拉伸强度和搭接剪切强度基本越高,即从大到小依次为含锂离聚体、含钠离聚体、含钾离聚体;含2价阳离子离聚体的离解温度从大到小依次为含钙离聚

  20. Application of Environmental Friendly Flame Retardants Made of Gray Aluminum and Boron Mud in Styrene Butadiene Rubber%硼泥、铝灰制备的环保阻燃剂在丁苯橡胶中的应用研究

    Institute of Scientific and Technical Information of China (English)

    仲维娜; 刘大晨

    2012-01-01

    以工业废料铝灰和硼泥制备主要成分为水滑石的环保阻燃剂,并将其添加到丁苯橡胶(SBR)中,研究其对阻燃性能和力学性能的影响.结果表明,随环保阻燃剂用量的增加,SBR的阻燃性能提高.使用硼泥、铝灰制备的环保阻燃剂为主的复配阻燃体系后,阻燃效果更好.但环保阻燃剂的大量使用会导致硫化胶物理机械性能下降,采用偶联剂处理后,SBR力学性能提高.%This research used the environmental friendly flame retardants which were made of some in- dustrial waste, i. e. , Gray aluminum and boron mud and had Layered Double Hydroxide (LDH) as its ma- jor component, and added these flame retardants into styrene butadiene rubber(SBR) to study its effect on the burning behaviour and mechanical characteristics on Emulsion-polymerized styrene butadiene rub- ber. The results showed that the burning behaviour of SBR was improved with increasing amount of these environmental friendly flame retardants. With the mating systems dominated by the environmental friendly flame retardants,it has very good flame residence performance. Using environmental friendly flame retard- ants in large amount will result in reduced physical and mechanical characteristics of vulcanixed rubber, then methods of modified flame retardants and reinforcement of ru6ber are taken into account to improve the mechanical properties of SBR

  1. Styrene-Based Copolymer for Polymer Membrane Modifications

    Directory of Open Access Journals (Sweden)

    Harsha Srivastava

    2016-05-01

    Full Text Available Poly(vinylidene fluoride (PVDF was modified with a styrene-based copolymer. The crystalline behavior, phase, thermal stability, and surface morphology of the modified membranes were analyzed. The membrane surface roughness showed a strong dependence on the styrene-acrylonitrile content and was reduced to 34% for a PVDF/styrene-acrylonitrile blend membrane with a 40/60 ratio. The thermal and crystalline behavior confirmed the blend miscibility of both polymers. It was observed in X-ray diffraction (XRD experiments that the modified PVDF membranes show a drastic reduction in their crystallinity. The neat PVDF membrane has the highest degradation rate, which decreased with the addition of the styrene-based copolymer.

  2. Surface modification of carbon black for the reinforcement of polycarbonate/acrylonitrile–butadiene–styrene blends

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, B.B. [School of Chemical Engineering, Fuzhou University, Fuzhou 350108 (China); Chen, Y. [School of materials Engineering, Fujian Agriculture and Forestry University, Fuzhou 350002 (China); Wang, F. [School of Chemical Engineering, Fuzhou University, Fuzhou 350108 (China); Hong, R.Y., E-mail: rhong@suda.edu.cn [School of Chemical Engineering, Fuzhou University, Fuzhou 350108 (China); College of Chemistry, Chemical Engineering and Materials Science & Key Laboratory of Organic Synthesis of Jiangsu Province, Soochow University, SIP, Suzhou 215123 (China)

    2015-10-01

    Highlights: • CB was modified through the method of oxygen plasma treatment. • Surface modified CB applied in PC/ABS blends. • The treated CB showed better compatibility in PC/ABS blends. • PC/ABS blends with treated CB showed better mechanical and thermal properties. - Abstract: The surface of carbon black was modified by oxygen plasma treatment for different times (10, 20 and 30 min). In order to increase the applicability of carbon black (CB), functional groups were grafted on the generally inert surface of CB using oxygen plasma. The surface compositional and structural changes that occurred on CB were investigated by SEM, FT-IR, Raman spectroscopy, XRD and BET. Subsequently, CB reinforced polycarbonate (PC)/acrylonitrile-butadiene-styrene (ABS) composites were prepared by internal batch mixing with the addition of different content of CB (3, 6, 9, 12 wt%). The morphology of PC/ABS/CB (7/3/6 wt%) nanocomposites was studied through scanning electron microscopy. Observations of SEM images showed that the plasma-treated CB had a better dispersion in the blend matrix. Moreover, the mechanical tests showed that the tensile strength and impact strength were improved by 32.4% and 22.5%, respectively, with the addition of plasma-treated CB. In addition, the thermal stability was improved and glass transition temperatures of both PC and ABS increased as shown by TGA and DSC, respectively.

  3. Surface modification of carbon black for the reinforcement of polycarbonate/acrylonitrile–butadiene–styrene blends

    International Nuclear Information System (INIS)

    Highlights: • CB was modified through the method of oxygen plasma treatment. • Surface modified CB applied in PC/ABS blends. • The treated CB showed better compatibility in PC/ABS blends. • PC/ABS blends with treated CB showed better mechanical and thermal properties. - Abstract: The surface of carbon black was modified by oxygen plasma treatment for different times (10, 20 and 30 min). In order to increase the applicability of carbon black (CB), functional groups were grafted on the generally inert surface of CB using oxygen plasma. The surface compositional and structural changes that occurred on CB were investigated by SEM, FT-IR, Raman spectroscopy, XRD and BET. Subsequently, CB reinforced polycarbonate (PC)/acrylonitrile-butadiene-styrene (ABS) composites were prepared by internal batch mixing with the addition of different content of CB (3, 6, 9, 12 wt%). The morphology of PC/ABS/CB (7/3/6 wt%) nanocomposites was studied through scanning electron microscopy. Observations of SEM images showed that the plasma-treated CB had a better dispersion in the blend matrix. Moreover, the mechanical tests showed that the tensile strength and impact strength were improved by 32.4% and 22.5%, respectively, with the addition of plasma-treated CB. In addition, the thermal stability was improved and glass transition temperatures of both PC and ABS increased as shown by TGA and DSC, respectively

  4. Reinforcement of Styrene-Butadiene Rubber with Silica Modified by Silane Coupling Agents: Experimental and Theoretical Chemistry Study%硅烷偶联剂改性白炭黑补强丁苯橡胶:实验和量化研究

    Institute of Scientific and Technical Information of China (English)

    任慧; 屈一新; 赵素合

    2006-01-01

    The properties of styrene-butadiene rubber (SBR) reinforced by modified silica was investigated according to national standards. Silica was modified by silane coupling agents KH-570, KH-590, and KH-792. The optimized geometries of molecular modified silica reinforced SBR were obtained by using B3LYP calculation of density functional theory with the 6-31+G basis sets. The natural bond orbital analyses were carried out. The Si-O bond length of silica modified by KH-792 was the shortest and the electronegative of O was the highest. It indicated that the connection between silica and KH-792 was the tightest. Higher tensile strength and elongation of reinforced SBR was obtained by silica modified with the KH-792. It was caused by large delocalization of lone pair electrons of the two N atoms in KH-792. The S-C bond length in silica modified by KH-590 was longer than the ordinary S-C bond length. Then the sulfur free radical (·S·) was produced more easily in vulcanization. The degree of crosslink was increased by the cross-linkage of the rubber molecule and the sulfur free radical. That was why the highest stress and tear strength of reinforced SBR was produced when silane coupling agent KH-590 was used. The calculation results was in accord with experimental data.

  5. Fatigue resistance of starch/carbon black/styrene-butadiene rubber composites%淀粉/炭黑/丁苯橡胶复合材料的抗疲劳性能

    Institute of Scientific and Technical Information of China (English)

    杨磊; 吴友平

    2012-01-01

    Starch/carbon black( CB)/styrene-bu-tadiene rubber (SBR) composites were prepared by emulsion blending with small amount of starch equiv-alently replacing CB , and the effect of starch amount on fatigue resistance of the composites was investigated. The results showed that the optimum replacing amount of starch was 5-8 phr when styrene-butadi-ene latex was 100 phr, the total amount of CB and starch was 50 phr. Under this condition, the fatigueresistance of starch/CB/SBR composites was improved evidently. The fatigue resistance of starch/ CB/SBR composites had a certain correlation with cutting resistance, trouser tear strength and loss factor.%采用乳液共混法,用少量淀粉等量替代炭黑,制备淀粉/炭黑/丁苯橡胶(SBR)复合材料,研究了淀粉用量对复合材料抗疲劳性能的影响.结果表明,当丁苯胶乳为100份、炭黑与淀粉的总量为50份时,淀粉最佳替代量为5~8份,在此条件下复合材料的抗疲劳性能大幅度提高;淀粉/炭黑/SBR复合材料的抗疲劳性能与硫化胶的抗切割性能、裤形撕裂强度以及损耗因子有一定的相关性.

  6. Propriedades Mecânicas de Blendas de Nylon-6/Acrilonitrila-EPDM-Estireno (AES Compatibilizadas com Copolímero Acrílico Reativo (MMA-MA Mechanical Properties of Nylon-6/Acrylonitrile-EPDM-Styrene (AES Blends Compatibilized with Reactive Acrylic Copolymer (MMA-MA

    Directory of Open Access Journals (Sweden)

    Adriane Bassani

    2002-01-01

    Full Text Available Foram estudadas blendas de nylon-6 com copolímero de acrilonitrila/EPDM/estireno (AES utilizando, como agentes compatibilizantes, uma série de copolímeros reativos de metacrilato de metila-anidrido maleico (MMA-MA. As unidades anidrido maleico (MA, destes copolímeros, podem reagir com os grupos finais de cadeia do nylon-6. Como verificado através de reometria de torque, os copolímeros MMA-MA podem gerar copolímeros in situ na interface das blendas durante o processamento. O principal enfoque deste trabalho foi estudar os efeitos da funcionalidade e concentração dos grupos anidrido maleico do compatibilizante sobre as propriedades mecânicas das blendas. Os resultados mostraram que a incorporação dos copolímeros MMA-MA melhorou significativamente a resistência ao impacto sob entalhe das blendas nylon-6/AES. As blendas contendo copolímero MMA-MA com 1,3% em peso de MA podem ser classificadas como supertenazes e mantêm sua tenacidade em temperaturas abaixo de zero.Blends of nylon-6 with acrylonitrile/EPDM/styrene (AES using a series of methyl methacrylate-maleic anhydride (MMA-MA copolymers as compatibilizing agents were prepared. The maleic anhydride (MA units in the copolymers are capable to react with the nylon-6 end groups. The MMA-MA copolymer has a potencial to form in situ copolymers at the blend interface during melt processing as indicated by torque rheometry tests. This study focuses on the effects of functionality and concentration of the reactive maleic anhydride units of the compatibilizer on the mechanical properties of these blends. The results show that incorporation of the MMA-MA copolymer significantly improves the impact strength of nylon-6/AES blends. The blend containing 1.3wt% of MA in the copolymer is supertough at room temperature, and remains tough at subzero temperatures.

  7. 顶空气相色谱法测定丙烯腈-苯乙烯(AS)塑料中残留的7种单体%Determination of 7 residual monomers in acrylonitrile-styrene plastic by gas chromatography with head space sampler

    Institute of Scientific and Technical Information of China (English)

    朱文亮; 周勇; 陈晓鹏; 谭锦萍; 吴炜亮

    2012-01-01

    A reliable method had been developed for determination of 7 residual monomers in acrylonitrile- styrene (AS) plastic by headspace-gas chromatography. The samples were completely dissolved into N, N-diethylformamide,and then the gas after achieved equilibrium in the headspace bottle was extracted by headspace injection equipment for gas chromatography analysis. The optimum conditions of gas chromatography and headspace injection were obtained by experiments. The optimum conditions of headspace injection were usage of solvent 3mL,heating temperature 120℃ ,time for equilibrium 40min. The average recoveries of 7 residual monomers were 95.71%-106.89%,the detection limits were 0.25N1.0mg/kg. The analysis method not only improved detection efficiency,but also cut down the detection cost. Meanwhile,this method was simple, rapid,accurate,and sensitive.%建立了顸空气相色谱法测定丙烯腈-苯乙烯(AS)塑料中7种残留单体的分析方法。以N,N-二甲基甲酰胺为溶剂溶解AS塑料,于顶空装置中平衡后,进样进行气相分析。通过实验得到了优化的气相色谱分离条件及顶空条件,其中优化的顸空条件为溶剂使用量3mL,加热温度120℃,平衡时间40min。7种残留单体的平均回收率为95.71%-106.89%,检出限为0.25-1.0mg/kg。该方法既提高了检测效率,又降低了检测成本。同时,此方法还具有简便、快速、灵敏、准确等优点.

  8. Intumescent flame retardant prepared by inverse suspension polymerization and its application in styrene-butadiene rubber%用反相悬浮聚合法制备膨胀型阻燃剂及其在丁苯橡胶中的应用

    Institute of Scientific and Technical Information of China (English)

    朱启龙

    2012-01-01

    The sodium polyacrylate-in situ encapsulated intumescent flame retardant ( IFR ) was prepared in the inverse suspension polymerization of sodium acrylate by adding ammonium polyphosphate, pentaerythritol and melamine, and Fourier transform infrared spectroscopy was used to characterize the structure of the flame retardant. The effects of melamine amount and the mass ratio of ammonium polyphosphate to pentaerythritol on the flame retar-dancy of styrene-butadiene rubber ( SBR ) vulcani-zates were investigated, the thermal property of flame retardant SBR was studied by thermogravime-try, and the combustion surface morphology of SBR filled with IFR was observed by scanning electron microscopy. The results showed that when the mass fraction of melamine was 3. 0% in IFR system, the mass ratio of ammonium polyphosphate to pentaerythritol was 4. 00 to 5. 67, the carbon residue yield of the system was the highest and the flame retardan-cy was better. The flame retardancy of SBR with IFR was improved correspondingly. When the IFR mass fraction was 30% in styrene-butadiene rubber vul-canizate, the oxygen index of the flame retardant rubber could achieve up to 27. 5% ; the SBR filled with IFR could form a relatively dense layer of carbon foam when it was burned, indicating that the IFR had a better intumescent flame retardant effect on SBR.%采用反相悬浮法聚合丙烯酸钠,同时将化学膨胀阻燃体系( IFR)三组分聚磷酸铵、季戊四醇和三聚氰胺加入到聚合体系中进行原位包裹,用傅里叶变换红外光谱时聚合产物的结构进行了表征,研究了三聚氰胺用量和聚磷酸铵与季戊四醇配比对丁苯橡胶硫化胶阻燃效果的影响,采用热重法分析了阻燃丁苯橡胶的热性能,并通过扫描电镜观察了添加IFR的丁苯橡胶在燃烧后表面的微现形态.结果表明,三聚氰胺的质量分数为IFR体系的3.0%、聚磷酸铵与季戊四醇的质量比为4.00~5.67时IFR体系的剩炭率最高,阻

  9. Morphology and Dynamic Mechanical Properties of Styrene Containing Tri-Block Copolymers for Electromagnetic Wave Interaction Applications

    Science.gov (United States)

    Peddini, S.; Mauritz, K.; Nikles, D.; Weston, J.

    2008-03-01

    Styrene containing triblock copolymers, namely poly(styrene-ethylene/butylene-styrene) (SEBS) and poly(styrene-butadiene-styrene)] (SBS), were selectively modified by attaching polar groups to facilitate the in-growth of an inorganic component. In case of SEBS, the styrene block was sulfonated, and in SBS, the butadiene block was hydroxylated. The extent of modification was determined by analytical and spectroscopic methods. This presentation shows the morphology and dynamical mechanical properties of both block copolymers before and after modification. Nanocomposites of these block copolymers were prepared by inclusion of magnetic metal oxides via an in-situ precipitation and self assembly processes and their morphology and dynamical mechanical properties were studied. Magnetic properties of these polymers filled with iron oxide nanoparticles were measured using an alternating gradient magnetometer (AGM) at room temperature to observe the magnetic hysteresis.

  10. Solubility parameter of poly(styrene-co-acrylonitrile)

    Science.gov (United States)

    Wohlfarth, Ch.

    This document is part of Subvolume D2 'Polymer Solutions - Physical Properties and their Relations I (Thermodynamic Properties: PVT -Data and miscellaneous Properties of polymer Solutions) of Volume 6 `Polymers' of Landolt-Börnstein - Group VIII `Advanced Materials and Technologies'.

  11. Effect of Nano-CaCO3 on Mechanical Properties of Filled Powdered Styrene-Butadiene Rubber Vulcanizate%纳米碳酸钙对填充型粉末丁苯橡胶硫化胶力学性能的影响

    Institute of Scientific and Technical Information of China (English)

    屈国梁; 陈雪梅; 马新胜

    2011-01-01

    Nano-CaCO3 filled styrene-butadiene rubber (SBR) powder P(SBR/CaCO3 ) was prepared with condensation coprecipitation method. The effect of nano-CaCO3 filling amount on the mechanical properties ofP(SBR/CaCO3) vulcanizate was studied. Then the material was compared with the bulk vulcanizate of mixed SBR/nano-CaCO3. It is found that when the nano-CaCO3 filling amount of P (SBR/CaCO3) vulcanizate and SBR/CaCO3 vulcanizate was the same, the mechanical properties of the former were basically superior to the later.When the filling amount of the nano-CaCO3 was 100 phr, the best mechanical properties of P (SBR/CaCO3) vulcanizate could be obtained, while the tensile strength could reach 13. 38 MPa which was obviously better than that of the SBR/CaCO3 one. It was originate from that the nano-CaCO3 in the former had better dispersion and interface bonding force than that in the later, which led to the better mechanical properties.%采用凝聚共沉法制备了纳米碳酸钙填充型粉末丁苯橡胶[P(SBR/CaCO3)],研究了纳米碳酸钙填充量对P(SBR/CaCO3)硫化胶力学性能的影响,并与块状丁苯橡胶/纳米碳酸钙机械混炼胶(SBR/CaCO3)硫化胶的进行了比较.结果表明:当纳米碳酸钙填充量相同时,P(SBR/CaCO3)硫化胶的力学性能基本上都优于SBR/CaCO3硫化胶的,当纳米碳酸钙填充量为100份时,P(SBR/CaCO3)硫化胶的力学性能最佳,其拉伸强度达13.38 MPa,明显好于SBR/CaCO3硫化胶的;纳米碳酸钙在P(SBR/CaCO3)硫化胶中比在SBR/CaCO3硫化胶中具有更好的分散性和界面结合力,因此具有更好的力学性能.

  12. 环保型填充油的乳化工艺及对丁苯橡胶充油效果的影响%Emulsification process of environmental-friendly extending oil and its influence on oil-extending effect of styrene-butadiene rubber

    Institute of Scientific and Technical Information of China (English)

    李晶; 王永峰; 吴宇

    2013-01-01

    Environmental-friendly oil-extended styrene-butadiene rubber ( SBR) was prepared with high Mooney viscosity SBR 1723 latex and environmental-friendly extending oil in which the mass fraction of polycyclic aromatic hydrocarbons was less than 3. 0% as materials, and the influences of emulsification process on emulsification effect of extending oil and properties of environmental-frendly oil-extended SBR were investigated. The results showed that the properties of the obtained environmental-friendly oil-extended SBR met the requirements of technical indicators under the conditions of emulsifying temperature 70 ℃ , extending oil/water/emulsi-fier (mass ratio) 100/200/2, stirring rate of agglomeration 163 r/min, agglomerating temperature 65 -70℃ when the emulsification process was used, by which the emulsifier disproportionated rosin acid soap was added into extending oil and stirred first and then the water was added.%以高门尼黏度丁苯橡胶(SBR) 1723基础胶浆和稠环芳烃质量分数低于3.0%的环保型橡胶填充油为原料制备环保型充油SBR,考察了乳化工艺对填充油乳化效果的影响以及所制得的环保型充油SBR的性能.结果表明,在以歧化松香酸钾皂为乳化剂、先将乳化剂加入填充油中搅拌一段时间后再加入水的油乳化方式、油乳化温度为70℃、填充油/水/乳化剂(质量比)为100/200/2以及凝聚时搅拌转速为163r/min、凝聚温度为65~70℃的条件下,所得产品的各项性能指标满足产品标准的要求.

  13. Application of styrene-butadiene rubber/organic montmorillonite nanocomposites synthesized by emulsion coprecipitated method in tire tread%乳液共沉法丁苯橡胶/有机蒙脱土纳米复合材料在轮胎胎面中的应用

    Institute of Scientific and Technical Information of China (English)

    张洪林; 高增亮; 宋国君; 谷正; 王振太; 李正勇; 李天真; 李迎; 邱艳平; 贾凤玲

    2009-01-01

    用乳液共沉法在中试装置上制备了丁苯橡胶/有机蒙脱土(SBR/OMMT)乳液共沉胶,研究了纳米复合材料的微观结构、力学性能、磨耗性能、加工性能等,讨论了其替代SBR在半钢子午线轮胎胎面中的应用效果.透射电子显微镜观察表明制备的乳液共沉胶是一种插层型纳米复合材料,OMMT与橡胶基质结合得较好;乳液共沉胶的拉伸强度、撕裂强度、硬度、回弹性等与SBR 1502基本相当,扯断伸长率和压缩永久变形有所增大,耐磨耗性能大幅度提高;以乳液共沉胶替代SBR 1502及部分炭黑在半钢子午线轮胎胎面中的应用效果良好,胶料的力学性能、加工性能及成品胎性能均能满足工业生产要求.%Styrene-butadiene rubber(SBR)/organic montmorillonite(OMMT) nanocomposites were synthesized by emulsion coprecipitation method in pilot plant. The structure, mechanical properties, abrasion properties and processing properties of the nanocomposites were studied. And the application of the nanocomposites in tread of semi-steel radical tire of SBR 1502 was investingated. The results of transmission electron microscope showed that the purpose products were intercalation nanocomposites, and the bond between OMMT and SBR matrix was better. The SBR/OMMT nanocomposites had similar tensile strength, tear strength, hardness and resilience to SBR 1502, while the elongation at break, compression set and abrasion properties were higher. The effect of SBR/OMMT composites in the application of tread of semi-steel radical tire instead of SBR 1502 and carbon black was good, and the mechanical properties, processing properties of the composites and the performance of the finished tire could meet requirements of production.

  14. POLYMER-SUPPORTED LANTHANIDE COMPLEXES FOR THE POLYMERIZATION OF BUTADIENE

    Institute of Scientific and Technical Information of China (English)

    YU Guangqian; LI Yuliang; LIU Chongming

    1992-01-01

    The characteristics of styrene-acrylic acid copolymer supported lanthanide complexes(SAAC Ln)(Ln=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) were described.butadiene, a peak in activity appeared at Nd and Pr, Sm, Eu and the heavy lanthanides exhibited low or no activities. The effects of some factors on the activities were discussed. The microstructure of the polymers obtained with all the lanthanides in the series were the same and the content of cis-1,4 polybutadiene attained was more than 98%.

  15. Compatibilization of blends of low density polyethylene and poly(vinyl chloride) by segmented EB(SAN-block-EB)(n) block copolymers

    NARCIS (Netherlands)

    Kroeze, E; ten Brinke, G.; Hadziioannou, G

    1997-01-01

    Hydrogenated segmented poly[butadiene-block-((styrene-co-acrylonitrile)-block-butadiene)(n)] block copolymers, which were developed by use of the polymeric iniferter technique, were tested for their compatibilizing capacities for (10/90) LDPE/PVC blends. The acrylonitrile content of the SAN blocks o

  16. Reinforcement of hydrogenated carboxylated nitrile-butadiene rubber by multi-walled carbon nanotubes

    International Nuclear Information System (INIS)

    Hydrogenated carboxylated acrylonitrile-butadiene rubber (HXNBR) and multi-walled carbon nanotubes (MWCNT) composites were prepared. The dispersion of MWCNT in HXNBR matrix was evaluated by field emission scanning electron microscopy. HXNBR/MWCNT composite had shorter scorch time and optimum curing time compared with that of unfilled HXNBR. The tensile strength and modulus of HXNBR/MWCNT composites increased with increasing MWCNT content. Mooney-Rivlin equation was used to describe the stress-strain behavior of unfilled HXNBR and the strain amplification factor was taken into account for HXNBR/MWCNT composites. The Mullins effect and dynamic mechanical properties of HXNBR/MWCNT composite were also investigated.

  17. Synthesis of SAN-PB-SAN triblock copolymers via a ''living'' copolymerization with macro-photoiniferters

    NARCIS (Netherlands)

    Kroeze, E; de Boer, B.; ten Brinke, G.; Hadziioannou, G

    1996-01-01

    A technique is described for the synthesis of poly((styrene-co-acrylonitrile)-block-butadiene-block-(styrene-co-acrylonitrile)) (SAN-PB-SAN) triblock copolymers through polybutadiene-based photo-iniferters. Dihydroxy- and dicarboxy-terminated polybutadienes were transformed into the chloro-terminate

  18. 21 CFR 180.22 - Acrylonitrile copolymers.

    Science.gov (United States)

    2010-04-01

    ..., preferably with animals exposed in utero to the chemical, (2) studies of multigeneration reproduction with... between acrylonitrile monomer and cyanide ion, and (6) a literature search on the effects of...

  19. Recycling of engineering plastics from waste electrical and electronic equipments: influence of virgin polycarbonate and impact modifier on the final performance of blends.

    Science.gov (United States)

    Ramesh, V; Biswal, Manoranjan; Mohanty, Smita; Nayak, Sanjay K

    2014-05-01

    This study is focused on the recovery and recycling of plastics waste, primarily polycarbonate, poly(acrylonitrile-butadiene-styrene) and high impact polystyrene, from end-of-life waste electrical and electronic equipments. Recycling of used polycarbonate, acrylonitrile-butadiene-styrene, polycarbonate/acrylonitrile-butadiene-styrene and acrylonitrile-butadiene-styrene/high impact polystrene material was carried out using material recycling through a melt blending process. An optimized blend composition was formulated to achieve desired properties from different plastics present in the waste electrical and electronic equipments. The toughness of blended plastics was improved with the addition of 10 wt% of virgin polycarbonate and impact modifier (ethylene-acrylic ester-glycidyl methacrylate). The mechanical, thermal, dynamic-mechanical and morphological properties of recycled blend were investigated. Improved properties of blended plastics indicate better miscibility in the presence of a compatibilizer suitable for high-end application.

  20. Species differences in metabolism of 1,3-butadiene

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, R.F.

    1995-02-01

    1,3-Butadiene (BD) is a 4-carbon gaseous compound with two double bonds. Used in high tonnage to make styrene-butadiene polymers in the rubber industry. Because of large amounts in use, BD was tested for toxicity in 2-year inhalation exposures of both Sprague-Dawley rats and B6C3F{sub 1} mice. The results of the two-species studies were dramatically different. In the initial study in mice, BD was shown to be a potent multiple-site carcinogen at exposure levels of 625 and 1250 ppM. There were increased incidences of neoplasia in the heart, lung, mammary gland, and ovary; malignant lymphomas resulted in early deaths of the mice so that the planned 2-year study was stopped after only 61 weeks of exposure. The second study in mice was conducted at much lower exposure concentrations (6.25, 20, 62.5, 200, and 625 ppM) and lasted 104 weeks. Increased incidences of hemangiosarcomas of the heart and lung neoplasia were observed in males exposed to 62.5 ppM BD, while females had increased lung neoplasia even at the 6.25 ppM exposure level. Early deaths from lymphomas were again observed at the high exposure concentration (625 ppm). A noncancer toxicity observed in mice was a macrocytic, megaloblastic anemia.

  1. Starch Modification by Graft Copolymerization of Acrylonitrile

    Institute of Scientific and Technical Information of China (English)

    刘瑞贤; 李莉; 茹宗玲; 张黎明; 高建平; 田汝川

    2003-01-01

    The graft copolymerization of acrylonitrile (AN) onto starch under the initiation of potassium permanganate was investigated. The effect of various reaction conditions on the graft copolymerization was studied. The relationships between the grafting rate and the initiator concentration of potassium permanganate, monomer acrylonitrile and backbone starch, as well as reaction temperature were established. The oxidation reaction of starch with manganic ions and valence changes of manganic ions during the graft copolymerization were discussed. The results show that manganic ion Mn7+ underwent a series of valence changes during the graft copolymerization: Mn(Ⅶ) → Mn(Ⅳ) → Mn(Ⅲ) → Mn(Ⅱ). The grafting rate of the graft copolymerization of acrylonitrile onto starch is also given.

  2. Coconut shell powder as cost effective filler in copolymer of acrylonitrile and butadiene rubber.

    Science.gov (United States)

    Keerthika, B; Umayavalli, M; Jeyalalitha, T; Krishnaveni, N

    2016-08-01

    Filler is one of the major additives in rubber compounds to enhance the physical properties. Even though numerous benefits obtained from agricultural by products like coconut shell, rice husk etc., still they constitute a large source of environmental pollution. In this investigation, one of the agricultural bye product coconut shell powder (CSP) is used as filler in the compounding KNB rubber. It shows the positive and satisfied result was achieved only by the use of filler Fast Extrusion Furnace (FEF) and coconut shell powder (CSP) which was used 50% in each. The effect of these fillers on the mechanical properties of a rubber material at various loading raging from 0 to 60PHP was studied. Mercaptodibanzothiazole disulphide (MBTS) was used as an accelerator. The result shows that presence of 25% and 50% of the composites has better mechanical properties like Hardness, Tensile strength, Elongation at break and Specific gravity when compared with other two combinations. Even though both 25% and 50% of composites shows good mechanical properties, 50% of CSP have more efficient than 25% of CSP. PMID:27060197

  3. RANDOM COPOLYMER BLENDS OF STYRENE, PARA-FLUORO STYRENE AND ORTHO-FLUORO STYRENE

    NARCIS (Netherlands)

    OUDHUIS, AACM; TENBRINKE, G; KARASZ, FE

    1993-01-01

    This study completes the investigation of the phase behaviour of polymer blends involving styrene (S), ortho-fluoro styrene (oFS) and para-fluoro styrene (pFS). As before, due to the proximity of the glass transition temperatures of most blends investigated, the miscibility or immiscibility is estab

  4. Organic chemistry. A rhodium catalyst for single-step styrene production from benzene and ethylene.

    Science.gov (United States)

    Vaughan, Benjamin A; Webster-Gardiner, Michael S; Cundari, Thomas R; Gunnoe, T Brent

    2015-04-24

    Rising global demand for fossil resources has prompted a renewed interest in catalyst technologies that increase the efficiency of conversion of hydrocarbons from petroleum and natural gas to higher-value materials. Styrene is currently produced from benzene and ethylene through the intermediacy of ethylbenzene, which must be dehydrogenated in a separate step. The direct oxidative conversion of benzene and ethylene to styrene could provide a more efficient route, but achieving high selectivity and yield for this reaction has been challenging. Here, we report that the Rh catalyst ((Fl)DAB)Rh(TFA)(η(2)-C2H4) [(Fl)DAB is N,N'-bis(pentafluorophenyl)-2,3-dimethyl-1,4-diaza-1,3-butadiene; TFA is trifluoroacetate] converts benzene, ethylene, and Cu(II) acetate to styrene, Cu(I) acetate, and acetic acid with 100% selectivity and yields ≥95%. Turnover numbers >800 have been demonstrated, with catalyst stability up to 96 hours.

  5. Organic chemistry. A rhodium catalyst for single-step styrene production from benzene and ethylene.

    Science.gov (United States)

    Vaughan, Benjamin A; Webster-Gardiner, Michael S; Cundari, Thomas R; Gunnoe, T Brent

    2015-04-24

    Rising global demand for fossil resources has prompted a renewed interest in catalyst technologies that increase the efficiency of conversion of hydrocarbons from petroleum and natural gas to higher-value materials. Styrene is currently produced from benzene and ethylene through the intermediacy of ethylbenzene, which must be dehydrogenated in a separate step. The direct oxidative conversion of benzene and ethylene to styrene could provide a more efficient route, but achieving high selectivity and yield for this reaction has been challenging. Here, we report that the Rh catalyst ((Fl)DAB)Rh(TFA)(η(2)-C2H4) [(Fl)DAB is N,N'-bis(pentafluorophenyl)-2,3-dimethyl-1,4-diaza-1,3-butadiene; TFA is trifluoroacetate] converts benzene, ethylene, and Cu(II) acetate to styrene, Cu(I) acetate, and acetic acid with 100% selectivity and yields ≥95%. Turnover numbers >800 have been demonstrated, with catalyst stability up to 96 hours. PMID:25908817

  6. 29 CFR 1910.1045 - Acrylonitrile.

    Science.gov (United States)

    2010-07-01

    ... addition, contact lenses should not be worn in areas where eye contact with acrylonitrile can occur. v... eye exposure. The employer shall assure that no employee is exposed to skin contact or eye contact... eye or skin contact with liquid AN may occur, the employer shall provide at no cost to the...

  7. The influence of carbon black on curing kinetics and thermal aging of acrylonitrile–butadiene rubber

    Directory of Open Access Journals (Sweden)

    Jaroslava Budinski-Simendić

    2009-10-01

    Full Text Available Elastomers based on a copolymer of butadiene and acrylonitrile (NBR have excellent oil resistance but are very sensitive for degradation at very high temperatures. The aim of this applicative contribution was to determine the effect of high abrasion furnace carbon black with primary particle size 46 nm on aging properties of elastomeric materials based on NBR as network precursor. The curing kinetics was determined using the rheometer with an oscillating disk, in which the network formation process is registered by the torque variation during time. The vulcanizates were obtained in a hydraulic press at 150 °C. The mechanical properties of elastomeric composites were determined before and after thermal aging in an air circulating oven. The reinforcing effect of the filler particles was assessed according to mechanical properties before and after aging.

  8. Surface amination of poly(acrylonitrile)

    OpenAIRE

    Hartwig, Andreas; Mulder, Marcel; Smolders, Cees A.

    1994-01-01

    The surface amination of poly (acrylonitrile) by ammonia plasma treatment has been studied. Furthermore, two other surface modification techniques have been investigated, the plasma chemical decomposition of an amino group containing chemical (tris-(2-aminoethyl)amine) onto the polymer surface and the surface reduction by lithium aluminium hydride. The three different methods are compared with respect to the adhesion improvement of the coatings onto the modified surfaces.

  9. 21 CFR 177.1040 - Acrylonitrile/styrene copoly-mer.

    Science.gov (United States)

    2010-04-01

    ...: Substances Limitation Condensation polymer of toluene sulfonamide and formaldehyde 0.15 pct maximum. (c... of Polymer Extracted from Barex 210 Resin Pellets”; “Procedure for the Determination of Molecular... multilayer construction by ASTM method D-1434-82, “Standard Method for Determining Gas...

  10. Thermodynamics of coil-hyperbranched poly(styrene-b-acrylated epoxidized soybean oil) block copolymers

    Science.gov (United States)

    Lin, Fang-Yi; Hohmann, Austin; Hernández, Nacú; Cochran, Eric

    Here we present the phase behavior of a new type of coil-hyperbranched diblock copolymer: poly(styrene- b-acrylated epoxidized soybean oil), or PS-PAESO. PS-PAESO is an example of a biorenewable thermoplastic elastomer (bio-TPE). To date, we have shown that bio-TPEs can be economical commercial substitutes for their petrochemically derived analogues--such as poly(styrene- b-butadiene- b-styrene) (SBS)--in a range of applications including pressure sensitive adhesives and bitumen modification. From a polymer physics perspective, PS-PAESO is an interesting material in that it couples a linear coil-like block with a highly branched block. Thus in contrast to the past five decades of studies on linear AB diblock copolymers, coil-hyperbranched block copolymers are relatively unknown to the community and can be expected to deviate substantially from the standard ``universal'' phase behavior in the AB systems. To explore these new materials, we have constructed a library of PS-PAESO materials spanning a range of molecular weight and composition values. The phase transition behavior and the morphology information will be interpreted by isochronal temperature scanning in dynamic shear rheology, small angle X-ray scattering and the corresponding transmission electron microscopy.

  11. Application of gamma irradiation for incorporation of rubber powder in the formulations of acrylonitrile-butadiene rubber (NBR)

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-01

    Full text: Polymeric materials do not decompose easily, disposal of waste polymers is a major environmental problem of global character. Recycling is an economical alternative and environmentally recommended for polymers consumed and discarded by society. As regards the rubber in object, its natural decomposition is much slower due to their highly crosslinked, in three-dimensional networks, structures which makes it an infusible and insoluble material. Moreover, these three dimensional structures entails several problems for their recovery and reprocessing. The aim of this paper was to study the behavior of NBR rubber recycle. It was used rubber powder from industry. The powder was irradiated in master-batch composition and used directly in classical formulations for rubber vulcanization. The master-batch processed was irradiated at doses of 50, 100 and 150kGy in {sup 60}Co source at 5 kGy s{sup -1} rate, at room temperature. Gamma radiation created active sites during devulcanization that promoted further integration of the rubber powder in formulations for commercial use. The processes were compared and their products were characterized by analytical methods of the physical properties such as tensile strength and elongation. The greatest change in the properties of polymeric materials by exposure to ionizing radiation resulted mainly of two main reactions occurring in the polymer molecule: chains scission (degradation) and crosslinking. Although these two processes occur simultaneously in all the polymers, the predominance of one or other effect depends mainly of the chemical structure of each polymer, and the irradiation conditions. In the results was observed the behavior of nitrile rubber under different doses and radiation improvement of the mechanical properties. (author)

  12. Commercial Application of the XYA-5 Catalyst in Acrylonitrile Unit

    Institute of Scientific and Technical Information of China (English)

    Li Zhengguang

    2008-01-01

    The XYA-5 catalyst was first applied in commercial scale on an 80-kt/a acrylonitrile unit at the Daqing Refining and Chemical Company.Test results had shown that the once-through yield of acrylonitrile exceeded 80% with the unit consumption of propylene reaching 1032 kg on each ton of acryionitrile.The product quality could be easily put under control and the distribution of reaction products was reasonable with good cleaning performance and stability of the catalyst that was suitable for use on this commercial unit.

  13. Polyacrylamide polymers derived from acrylonitrile without intermediate isolation

    Energy Technology Data Exchange (ETDEWEB)

    Norton, C.J.; Falk, D.O.

    1977-04-05

    Hydrolyzed and neutralized acrylonitrile is polymerized in solution without isolation to produce a high molecular weight polyacrylamide useful for mobility control in secondary recovery of petroleum. The polyacrylamide optionally may be hydrolyzed, methylolated, and sulfomethylated to further enhance its water-thickening properties. This procedure reduces the cost of making polyacrylamide. (5 claims)

  14. Exposure to styrene and chronic health effects

    DEFF Research Database (Denmark)

    Kolstad, Henrik; Juel, K; Olsen, J H;

    1995-01-01

    To study the occurrence of non-malignant diseases and solid cancers in workers exposed to styrene in the Danish reinforced plastics industry.......To study the occurrence of non-malignant diseases and solid cancers in workers exposed to styrene in the Danish reinforced plastics industry....

  15. Helbredsrisici ved eksponering for styren i glasfiberplastindustrien

    DEFF Research Database (Denmark)

    Kolstad, Henrik Albert; Ebbehøj, Nielse; Bonde, Jens Peter;

    2012-01-01

    or relevant exposure levels. We recommend reconsideration of the current Danish threshold limit value of 25 ppm, biological monitoring of styrene exposed workers, and epidemiological analyses of styrene exposure levels and long-term health effects among employees of the Danish reinforced plastics industry....

  16. A New Quenching Process and Tower to Improve the Recovery of Acrylonitrile

    Institute of Scientific and Technical Information of China (English)

    甘永胜; 顾军民; 方永成

    2004-01-01

    Quenching process and design of the quenching tower in acrylonitrile production in China were studied in order to decrease the polymerization loss of acrylonitrile in the quenching tower. Based on the research of acrylonitrile polymerization in the quenching tower, a new quenching process was proposed to avoid the disadvantages of the original process. Two kinds of internals were installed to improve the performance of the quenching tower. Through a series of air-flow and real-flow model experiments, the new quenching process and new design were showed to be successful in enhancing the mass and heat transfer in the vapor-liquid system and decreasing the loss of acrylonitrile.Industrial application showed satisfactory results of decrease of the acrylonitrile loss in the quenching tower by about 4.5% and increase of the acrylonitrile recovery of the whole plant by more than 4%.

  17. Styrene Aziridination by Iron(IV) Nitrides.

    Science.gov (United States)

    Muñoz, Salvador B; Lee, Wei-Tsung; Dickie, Diane A; Scepaniak, Jeremiah J; Subedi, Deepak; Pink, Maren; Johnson, Michael D; Smith, Jeremy M

    2015-09-01

    Thermolysis of the iron(IV) nitride complex [PhB(tBuIm)3Fe≡N] with styrene leads to formation of the high-spin iron(II) aziridino complex [PhB(tBuIm)3Fe-N(CH2CHPh)]. Similar aziridination occurs with both electron-rich and electron-poor styrenes, while bulky styrenes hinder the reaction. The aziridino complex [PhB(tBuIm)3Fe-N(CH2CHPh)] acts as a nitride synthon, reacting with electron-poor styrenes to generate their corresponding aziridino complexes, that is, aziridine cross-metathesis. Reaction of [PhB(tBuIm)3Fe-N(CH2CHPh)] with Me3SiCl releases the N-functionalized aziridine Me3SiN(CH2CHPh) while simultaneously generating [PhB(tBuIm)3FeCl]. This closes a synthetic cycle for styrene azirdination by a nitride complex. While the less hindered iron(IV) nitride complex [PhB(MesIm)3Fe≡N] reacts with styrenes below room temperature, only bulky styrenes lead to tractable aziridino products. PMID:26179563

  18. Thermal Stability of Poly (acrylonitrile-methyl acrylate) Copolymers

    Institute of Scientific and Technical Information of China (English)

    HAN Na; ZHANG Xing-xiang; WANG Xue-chen

    2008-01-01

    Poly (acrylonitrile-methyl acrylate) copolymer was synthesized by water depositing polymerization and has a typical feed ratio of 85/15. And then 1 - 3 wt% lauryl alcohol maleic anhydride (LAM) was adopted as stabilizer to mix with the acrylonitrile based copolymer. The mixtures were characterized by using Fourier Transform Infrared Spectroscopy (FTIR), Nuclear Magnetic Resonance (1H NMR ), Gel Permeation Chromatography ( GPC ), Differential Scanning Calorimetry (DSC), optic microscope and Ubbelohde viscosimetryr etc. The melting point (Tm) and glass transition temperature (Tg) of the 85/15 AN/MA copolymer mixed with LAM all decrease with the increase of stabilizer content. The lowest Tg and Tm were 116.1 ℃ and 209. 1℃ respectively at the heating rate of 100℃/min when the content of LAM is 2 wt%. The 85°/15 AN/MA copolymer mixed with 1 - 3 w t% LAM possess good thermal stability up to 30 min at 220 ℃.

  19. Polymerization of Acrylonitrile with(Diisopropylamido)Bis(indenyl) Lanthanides

    Institute of Scientific and Technical Information of China (English)

    李刚; 张学全; 应来强; 巴小微; 崔冬梅; 唐涛; 金鹰泰

    2002-01-01

    The polymerization of acrylonitrile was studied using (diisopropylamido)bis(indenyl) lanthanides, Ind2LnN(i-Pr)2(Ln=Y, Yb) as a single-component catalyst. The effects of the amount of catalyst, monomer concentration and polymerization temperature on catalytic activity and molecular weight of polyacrylonitrile(PAN) were studied. The results show that the catalytic activity is raised obviously with rising polymerization temperature. The monomer conversion reaches 64% under polymerization temperature, monomer concentration and catalyst concentration are 50 ℃, 5.1 mol*L-1 and 0.3%(molar ratio) sequentially. The conversion and molecular weight of the polymer increase appreciably with adding additive, PhONa. When the molar ratio of PhONa to the catalyst is three, the conversion and the molecular weight is 76% and 1.32×104, respectively. The initiation mechanism for the polymerization of acrylonitrile was proposed.

  20. Radiation initiated copolymerization of allyl alcohol with acrylonitrile

    Energy Technology Data Exchange (ETDEWEB)

    Solpan, Dilek; Guven, Olgun [Hacettepe Univ., Ankara (Turkey). Dept. of Chemistry

    1996-07-01

    Copolymerization of allyl alcohol (AA) with acrylonitrile (AN) initiated by {gamma}-rays has been investigated to determine the respective reactivity ratios. Three different experimental techniques, namely Fourier Transform Infrared (FTIR), Ultraviolet (UV/vis) and elemental analysis (EA) have been used for the determination of copolymer compositions. Fineman-Ross (FR), Kelen-Tudos (KT), Non-Linear Least Square (NLLS) Analysis and Q-e methods have been applied to the three sets of experimental data. It has been concluded that data obtained from elemental analysis as applied to the Non-Linear Least Square approach gave the most reliable reactivity ratios as 2.09 and 0.40 for acrylonitrile and allyl alcohol, respectively. (Author).

  1. Radiation initiated copolymerization of allyl alcohol with acrylonitrile

    Science.gov (United States)

    Şolpan, Dilek; Güven, Olgun

    1996-07-01

    Copolymerization of allyl alcohol (AA) with acrylonitrile (AN) initiated by γ-rays has been investigated to determine the respective reactivity ratios. Three different experimental techniques, namely Fourier Transform Infrared (FTIR), Ultraviolet (UV/vis) and elemental analysis (EA) have been used for the determination of copolymer compositions. Fineman-Ross (FR), Kelen-Tüdös (KT), Non-Linear Least Square (NLLS) Analysis and Q-e methods have been applied to the three sets of experimental data. It has been concluded that data obtained from elemental analysis as applied to the Non-Linear Least Square approach gave the most reliable reactivity ratios as 2.09 and 0.40 for acrylonitrile and allyl alcohol, respectively.

  2. Hydrolyzed Poly(acrylonitrile) Electrospun Ion-Exchange Fibers

    OpenAIRE

    Jassal, Manisha; Bhowmick, Sankha; Sengupta, Sukalyan; Patra, Prabir K.; Walker, Douglas I.

    2014-01-01

    A potential ion-exchange material was developed from poly(acrylonitrile) fibers that were prepared by electrospinning followed by alkaline hydrolysis (to convert the nitrile group to the carboxylate functional group). Characterization studies performed on this material using X-ray photoelectron spectroscopy, scanning electron microscopy, Fourier-Transform infra-red spectroscopy, and ion chromatography confirmed the presence of ion-exchange functional group (carboxylate). Optimum hydrolysis co...

  3. Helbredsrisici ved eksponering for styren i glasfiberplastindustrien

    DEFF Research Database (Denmark)

    Kolstad, Henrik Albert; Ebbehøj, Nielse; Bonde, Jens Peter;

    2012-01-01

    or relevant exposure levels. We recommend reconsideration of the current Danish threshold limit value of 25 ppm, biological monitoring of styrene exposed workers, and epidemiological analyses of styrene exposure levels and long-term health effects among employees of the Danish reinforced plastics industry....... system effects with for instance reduced psychological performance, colour discrimination and hearing level following long-term styrene exposure above 10 ppm. There is moderate evidence of a causal association with cancer, but data are not sufficient to allow us to pinpoint specific cancers at risk...

  4. Species difference in metabolism of inhaled butadiene

    International Nuclear Information System (INIS)

    Chronic exposure of B6C3F1 mice and Sprague-Dawley rats to butadiene (BD) produced a very high incidence of cancer in mice while the incidence in rats was much lower with different tissues affected. Studies at this institute indicate that for equivalent exposures, the blood BD epoxide concentrations in mice are 5-fold higher than in rats and > 10-fold higher than in Cynomolgus monkeys. In this study, the profiles of urinary metabolites of butadiene were determined in Cynomolgus monkeys, F344/N rats, Sprague Dawley rats, B6C3F1 mice and Syrian hamsters, species containing widely divergent hepatic epoxide hydrolase (EH) activities. Animals were exposed for 2 hr to 8,000 ppm [14C]BD and 24-hr urine samples were analyzed for metabolites. Two major urinary metabolites were identified, N-acetyl-S-(-1(or 2)-3-butene-2(or 1)-ol)cysteine (1) and N-acetyl-S-(-4-butane-1,2-diol)cysteine (2). Monkeys exposed by inhalation produced primarily metabolite 2, while rodent species produced 1-4 times as much of 1 compared to 2. The ratio of 2/1 formation was related to the hepatic epoxide hydrolase activity in different species. The high 2/1 ratio in monkeys was consistent with the lower blood epoxide levels in this species. If BD metabolism by humans is similar to that in the monkey, exposure of humans to BD may result in lower tissue concentrations of reactive metabolites than an equivalent exposure of rodents. This has important implications for assessing the risk to humans of BD exposure based on rodent studies

  5. Design, synthesis and physical properties of poly(styrene–butadiene–styrene)/poly(thiourea-azo-sulfone) blends

    Indian Academy of Sciences (India)

    Ayesha Kausar

    2014-06-01

    A new aromatic azo-polymer, poly(thiourea-azo-sulfone), has been synthesized using 1-(4-thiocarbamoylaminophenylsulfonylphenyl)thiourea and diazonium salt solution. Conducting and thermally stable rubbery blends of poly(styrene-block-butadiene-block-styrene) (SBS) triblock copolymer and poly(thiourea-azo-sulfone) (PTAS) were produced by solution blending technique. PTAS possessed fine solubility in polar solvents and high molar mass 63 × 103 g moL-1. Microscopic analysis on SBS/PTAS blends revealed good adhesion between the two polymers without macro phase separation. Electrical conductivity measurement recommended that blending of SBS with 60% PTAS was sufficiently conducting 1.43 S cm-1. A relationship between PTAS loading and thermal stability of blends was observed. With the increasing PTAS content, 10% gravimetric loss was increased from 481 to 497 °C, while glass transition improved from 123 to 136 °C (better than neat SBS but lower than PTAS). The blends also established higher tensile strength (52.40–59.96 MPa) relative to SBS. Fine balance of properties renders new SBS/PTAS, potential engineering plastics for a number of aerospace relevance.

  6. Rapid prototyping of polymeric microstructures with a UV laser

    DEFF Research Database (Denmark)

    Jensen, Martin F.; McCormack, John E.; Helbo, Bjarne;

    2003-01-01

    ion implantation of the master tool to prolong the lifetime has also been investigated. For injection moulding, where the pressure and temperature is higher than in hot embossing a positive laser ablated Acrylonitrile-butadien-styrene co-polymer (ABS) structure was used, which subsequently has been...

  7. Media surface properties and the development of nitrifying biofilms in mixed cultures for wastewater treatment.

    OpenAIRE

    Stephenson, Tom; Reid, E.; Avery, L. M.; Jefferson, Bruce

    2013-01-01

    Plastic was tested to select biofilm support media that would enhance nitrification in the presence of heterotrophs. Eight different types (acrylonitrile butadiene styrene, nylon, polycarbonate, polyethylene, polypropylene, polytetraflouroethylene (PTFE), polyvinyl chloride and tufnol) were immersed in an aerobic fed-batch reactor receiving domestic settled wastewater. Nitrification rates did not correlate with biomass concentrations, nor surface roughness of the plastics as measured by atomi...

  8. Kinetic and equilibrium studies of acrylonitrile binding to cytochrome c peroxidase and oxidation of acrylonitrile by cytochrome c peroxidase compound I

    Energy Technology Data Exchange (ETDEWEB)

    Chinchilla, Diana, E-mail: Diana_Chinchilla@yahoo.com; Kilheeney, Heather, E-mail: raindropszoo@yahoo.com; Vitello, Lidia B., E-mail: lvitello@niu.edu; Erman, James E., E-mail: jerman@niu.edu

    2014-01-03

    Highlights: •Cytochrome c peroxidase (CcP) binds acrylonitrile in a pH-independent fashion. •The spectrum of the CcP/acrylonitrile complex is that of a 6c–ls ferric heme. •The acrylonitrile/CcP complex has a K{sub D} value of 1.1 ± 0.2 M. •CcP compound I oxidizes acrylonitrile with a maximum turnover rate of 0.61 min{sup −1}. -- Abstract: Ferric heme proteins bind weakly basic ligands and the binding affinity is often pH dependent due to protonation of the ligand as well as the protein. In an effort to find a small, neutral ligand without significant acid/base properties to probe ligand binding reactions in ferric heme proteins we were led to consider the organonitriles. Although organonitriles are known to bind to transition metals, we have been unable to find any prior studies of nitrile binding to heme proteins. In this communication we report on the equilibrium and kinetic properties of acrylonitrile binding to cytochrome c peroxidase (CcP) as well as the oxidation of acrylonitrile by CcP compound I. Acrylonitrile binding to CcP is independent of pH between pH 4 and 8. The association and dissociation rate constants are 0.32 ± 0.16 M{sup −1} s{sup −1} and 0.34 ± 0.15 s{sup −1}, respectively, and the independently measured equilibrium dissociation constant for the complex is 1.1 ± 0.2 M. We have demonstrated for the first time that acrylonitrile can bind to a ferric heme protein. The binding mechanism appears to be a simple, one-step association of the ligand with the heme iron. We have also demonstrated that CcP can catalyze the oxidation of acrylonitrile, most likely to 2-cyanoethylene oxide in a “peroxygenase”-type reaction, with rates that are similar to rat liver microsomal cytochrome P450-catalyzed oxidation of acrylonitrile in the monooxygenase reaction. CcP compound I oxidizes acrylonitrile with a maximum turnover number of 0.61 min{sup −1} at pH 6.0.

  9. BIOMARKERS IN CZECH WORKERS EXPOSED TO 1,3-BUTADIENE: A TRANSITIONAL EPIDEMIOLOGIC STUDY

    Science.gov (United States)

    All the biomarkers of exposure were correlated with the measurements of butadiene recorded by the air samplers. Although the correlation between hemoglobin adducts and exposure levels was strongest, urinary metabolites were also found to be very useful measures of butadiene...

  10. POLYMERIZATION OF ACRYLONITRILE WITH ORGANOLANTHANIDES AS SINGLE-COMPONENT CATALYSTS

    Institute of Scientific and Technical Information of China (English)

    Lai-qiang Ying; Xiao-wei Ba; Yu-ying Zhao; Gang Li; Tao Tang; Ying-tai Jin

    2001-01-01

    Ind2Y(μ-Et)2A1Et2 and Ind2LnN(i-Pr)2 (Ln = Y, Yb) were used as a single-component catalyst for the polymerization of acrylonitrile (AN) respectively. The regularity of polymerization of AN and stereoregularity of polyacrylonitrile (PAN) were also studied in both cases. Both catalysts can produce PAN with molecular weight from I0,000to 30,000. In addition, the catalytic activity and molecular weights were increased by the addition of PhONa.

  11. 46 CFR 154.1750 - Butadiene or vinyl chloride: Refrigeration system.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Butadiene or vinyl chloride: Refrigeration system. 154... and Operating Requirements § 154.1750 Butadiene or vinyl chloride: Refrigeration system. A refrigeration system for butadiene or vinyl chloride must not use vapor compression unless it: (a) Avoids...

  12. On the catalytic gas phase oxidation of butadiene to furan

    Energy Technology Data Exchange (ETDEWEB)

    Kubias, B.; Rodemerck, U. [Institut fuer Angewandte Chemie Berlin-Adlershof e.V., Berlin (Germany); Ritschl, F.; Meisel, M. [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Chemie

    1998-12-31

    Applying the thermochemical selectivity criterion of Hadnett et al. It is shown that the selectivity of the furan formation is not limited by a too low strength of the C-H bonds in furan when compared with the C-H bond dissociation energy in the educt molecule butadiene. In the oxidation of butadiene on a CsH{sub 2}PMo{sub 12}O{sub 40} catalyst a maximum yield of 22 mol% furan has been obtained. To improve this comparatively low furan yield oxidation activity of the catalyst must be lowered to prevent the consecutive reaction to maleic anhydride. (orig.)

  13. Gender differences in the metabolism of 1,3-butadiene to butadiene diepoxide in Sprague-Dawley rats

    Energy Technology Data Exchange (ETDEWEB)

    Thornton-Manning, J.R.; Dahl, A.R.; Bechtold, W.E. [and others

    1995-12-01

    1,3-Butadiene (BD), a gaseous compound used in the production of rubber, is a potent carcinogen in mice and a weak carcinogen in rats. The mechanism of BD-induced carcinogenicity is thought to involve genotoxic effects of its reactive epoxide metabolites butadiene monoepoxide (BDO) and butadiene diepoxide (BDO{sub 2}). Studies in our laboratory have shown that levels of the epoxides, particularly BDO{sub 2}, are greater in mice-the more sensitive species-than rats. While both epoxides are genotoxic in a number of assays, BDO{sub 2} is mutagenic in TK6 human lymphoblastoid cells at concentrations approximately 100-fold lower than BDO. Species differences in carcinogenicity of BD have posed a dilemma to investigators deciding which animal model is most appropriate for BD risk assessment.

  14. Radical-initiated controlled synthesis of homo- and copolymers based on acrylonitrile

    Science.gov (United States)

    Grishin, D. F.; Grishin, I. D.

    2015-07-01

    Data on the controlled synthesis of polyacrylonitrile and acrylonitrile copolymers with other (meth)acrylic and vinyl monomers upon radical initiation and metal complex catalysis are analyzed. Primary attention is given to the use of metal complexes for the synthesis of acrylonitrile-based (co)polymers with defined molecular weight and polydispersity in living mode by atom transfer radical polymerization. The prospects for using known methods of controlled synthesis of macromolecules for the preparation of acrylonitrile homo- and copolymers as carbon fibre precursors are estimated. The major array of published data analyzed in the review refers to the last decade. The bibliography includes 175 references.

  15. Application of control technology developed in the polyvinyl chloride industry to polymerization processes using acrylonitrile.

    Science.gov (United States)

    Schoultz, K S; Gideon, J A; Bochinski, J H

    1979-02-01

    Polymerization processes for PVC are sufficiently similar to acrylonitrile polymerization processes to allow a significant transfer of control technology. This transfer should be of value to manufacturers of polyacrylonitrile, ABS/SAN resins, nitrile elastomer and latex who will need to install extensive additional controls to comply with the new permanent standard for acrylonitrile scheduled to be issued by OSHA in late 1978. Control strategies and individual controls developed to limit worker exposure in the PVC industry are described and evaluated relative to applicability to acrylonitrile polymerization processes. PMID:495444

  16. Comparative study of the monomer grafting: ethylene, acetylene, 1,3-butadiene and estyrene in the matrix of recycled polytetrafluoroethylene (PTFE)

    International Nuclear Information System (INIS)

    In this study it is used the recycled polytetrafluoroethylene (PTFE), that with the gamma radiation under inert atmosphere or in presence of air, it is obtained free radicals and a posterior the monomer grafting (ethylene, acetylene, styrene or 1.3 butadiene), obtaining the copolymer polytetrafluoroethylene-g-monomer. It is studied the obtention of the polymer by two methods: by direct way, via grafting, where the polymer is irradiated in presence of monomer, and via grafting when the polymer is irradiated in absence of monomer and under inert or air. The characterization of the copolymer was performed by the techniques of infrared region absorption spectroscopy with Fourier transformation (FTIR), thermogravimetric (TGA) and derivative thermogravimetry (DTG), and percentage of mass grafting (DOG)

  17. 共聚物-深剂体系的气液平衡:新UNIFAC基团热力学模型与实验研究%Vapor-Liquid Equilibrium of Copolymer+solvent Systems:Experimental Data and Thermodynamic Modeling with New UNIFAC groups

    Institute of Scientific and Technical Information of China (English)

    Rogério A.G. Sé; Martín Aznar

    2008-01-01

    Vapor-liquid equilibrium (VLE)data for copolymer solutions are necessary for several chemical processes.However,VLE data for copolymer solutions in the published report are rare.In this study.experimental VLE data for binary systems copolymer+solvent were obtained using a gravimetric-sorption apparatus.The studied systems were hexane+poly(21%acrylonitrile-co-butadiene),hexanc+poly(33%acrylonitrile-co-butadiene),hexane+poly(51%acrylonitrile-co-butadiene),hexanc+poly(23%styrene-co-butadiene),hexane+poly(45%styrene-co-butadiene),and benzene+poly(44%styrene-co-methyl methacrylate)in the range 50-70℃.The experimental data were correlated with the UNIFAC and Elbro-FV group contribution models for the activity coefficient.Two sets of functional groups had been used to represent the monomers in copolymers:literature groups and new proposed groups.The mean deviations between experimental and calculated mass fractions about 2.4%with ElbroFV and 13.3%witll Zhong were observed when the groups proposed in this study were USed.and of 3.5%for E1bro-FV and 13.2%for Zhong when literature groups were used.

  18. Catalytic dehydrogenations of ethylbenzene to styrene

    NARCIS (Netherlands)

    Nederlof, C.

    2012-01-01

    This research work on the catalytic dehydrogenation of ethylbenzene (EB) to styrene (ST) had a primary goal of developing improved catalysts for dehydrogenation processes both in CO2 as well as with O2 that can compete with the conventional dehydrogenation process in steam. In order to achieve this

  19. Plane-interface-induced lignin-based nanosheets and its reinforcing effect on styrene-butadiene rubber

    OpenAIRE

    Jiang, C.; He, H.; P. Yu; Wang, D K; Zhou, L; D. M. Jia

    2014-01-01

    Lignin was viewed as a spherical microgel in aqueous alkali. While spread out in a monolayer or adsorbed on a surface, lignin was made up of flexible, disk-like molecules with approximately the same thickness of 2 nm. According to this principle, we employed the lamina of montmorillonite (MMT) as a plane template to anchor cationic lignin (CL) on its two sides, resulting in the formation of CL-MMT hybrid materials (CLM). The isotherm adsorption behavior and structure characteristics of CLM we...

  20. Mechanical properties of heterophase polymer blends of cryogenically fractured soy flour composite filler and poly(styrene-butadiene)

    Science.gov (United States)

    Reinforcement effect of cryogenically fractured soy Flour composite filler in soft polymer was investigated in this study. Polymer composites were prepared by melt-mixing polymer and soy flour composite fillers in an internal mixer. Soy flour composite fillers were prepared by blending aqueous dis...

  1. Synthesis and characterisation of polyelectrolytes based on polymers of diallyldimethyl ammonium chloride and poly(styrene-co-butadiene)

    OpenAIRE

    Svensson, David

    2012-01-01

    In printed electronics there are many polyelectrolytes to choose from. While polyelectrolytes such as polystyrene sulfonic acid can fulfill many ofthe desired functionalities of a semiconductor, there is a need for other polyelectrolytes with other functionalities, such as functionality at low airhumidity and better cross-linking possibilities, while still functioning as a good semiconductor.Within this thesis, there is a description of general polyelectrolytes, as well as various usages.The ...

  2. Excited State Spectra and Dynamics of Phenyl-Substituted Butadienes

    DEFF Research Database (Denmark)

    Wallace-Williams, Stacie E.; Schwartz, Benjamin J.; Møller, Søren;

    1994-01-01

    A combination of steady-state and dynamic spectral measurements are used to provide new insights into the nature of the excited-state processes of all-trans-1,4-diphenyl-1,3-butadiene and several analogs: 1,4-diphenyl- 1,3-cyclopentadiene, 1,1,4,4-tetraphenylbutadiene, 1,2,3,4-tetraphenyl-1...

  3. BARRIER PROPERTY AND STRUCTURE OF ACRYLONITRILE/ACRYLIC COPOLYMERS

    Institute of Scientific and Technical Information of China (English)

    YANG Zhenghua; LI Yuesheng

    1997-01-01

    A series of acrylonitrile (AN) copolymers with methyl acrylate (MA) or ethyl acrylate (EA) as comonomer (5-23 wt%) was prepared by free-radical copolymerization. The permeability coefficients of the copolymers to oxygen and carbon dioxide were measured at 1.0 MPa and at 30 ℃, and those to water vapor also measured at 100% relative humidity and at 30 ℃. All the AN/acrylic copolymers are semicrystalline. As the acrylate content increase, the permeability coefficients of the copolymers to oxygen and carbon dioxide are increased progressively, but those to water vapor are decreased progressively. The gas permeability coefficients of the polymers were correlated with free-volume fractions or the ratio of free volume to cohesive energy.

  4. ICAR ATRP of Acrylonitrile under Ambient and High Pressure

    Directory of Open Access Journals (Sweden)

    Zhicheng Huang

    2016-03-01

    Full Text Available It is well known that well-defined polyacrylonitrile (PAN with high molecular weight (Mw > 106 g·mol−1 is an excellent precursor for high performance carbon fiber. In this work, a strategy for initiators for a continuous activator regeneration atom transfer radical polymerization (ICAR ATRP system for acrylonitrile (AN was firstly established by using CuCl2·2H2O as the catalyst and 2,2′-azobis(2-methylpropionitrile (AIBN as the thermal initiator in the presence of ppm level catalyst under ambient and high pressure (5 kbar. The effect of catalyst concentration and polymerization temperature on the polymerization behaviors was investigated. It is important that PAN with ultrahigh viscosity and average molecular weight (Mη = 1,034,500 g·mol−1 could be synthesized within 2 h under high pressure.

  5. Determination of potentially carcinogenic compounds in food : trace analysis of vinylchloride, vinylidenechloride, acrylonitrile, epichlorohydrin and diethylpyrocarbonate

    NARCIS (Netherlands)

    Lierop, van J.B.H.

    1979-01-01

    Toxicological evidence shows that some monomers present in packaging materials may be carcinogenic. These monomers, notably vinylchloride, vinylidenechloride, acrylonitrile and epichlorohydrin, may migrate from the packaging material into the food. Therefore, severe limits are set to the contents of

  6. Hydration of acrylonitrile to produce acrylamide using biocatalyst in a membrane dispersion microreactor.

    Science.gov (United States)

    Li, Jiahui; Chen, Jie; Wang, Yujun; Luo, Guangsheng; Yu, Huimin

    2014-10-01

    In this work, a membrane dispersion microreactor was utilized for the hydration of acrylonitrile to produce acrylamide. Through observation using a microscopy, it was found that the acrylonitrile was dispersed into the continuous phase (the aqueous phase contains nitrile hydratase (NHase)) as droplets with a diameter ranged from 25 to 35 μm, hence the mass transfer specific surface area was significantly increased, and the concentration of acrylamide reached 52.5 wt% within 50 min. By contrast, in stirred tanks, the concentration of acrylamide only got 39.5 wt% within 245 min. Moreover, only a few amounts of acrylonitrile were accumulated in this microreactor system. Through optimizing the flow rate, the concentration of acrylamide reached 45.8 wt% within 35 min, the short reaction time greatly weakened the inhibition of acrylonitrile and acrylamide on the enzyme activity, which is suitable for prolonging the life of free cell.

  7. Synthesis and Characterization of a Novel Acrylonitrile Copolymer Containing Glucose Pendants

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    In this work, a novel sugar-containing copolymer was synthesized by the copolymerization of α-allyl glucoside (AG) with acrylonitrile (AN). The copolymers were characterized by NMR spectroscopy. It was found that acrylonitrile-based copolymers containing as high as 22wt.% of α-allyl glucoside can be synthesized by the free radical solution copolymerization of the two monomers in DMSO with AIBN as initiator.

  8. EFFECTS OF SOLVENT POLARITY ON FREE RADICAL COPOLY MERIZATION OF 5-HEXENOIC ACID AND ACRYLONITRILE

    Institute of Scientific and Technical Information of China (English)

    WANG Bing; XIE Shishan; CAO Mengjiun

    1987-01-01

    The effects of solvent polarity on free radical copolymerization of 5-hexenoic acid and acrylonitrile at 60℃ were studied. It was observed that as the polarity of solvents enhanced, both the copolymerization rate and the reactivity ratios r1, r2 increased, while the alternating tendency of monomer units in copolymer chain decreased. It is believed that the solvent polarity raises the reactivities of acrylonitrile monomer and its growing chain radical, but causes no distinct variation in those of 5-hexenoic acid.

  9. Simple replica micromolding of biocompatible styrenic elastomers.

    Science.gov (United States)

    Borysiak, Mark D; Bielawski, Kevin S; Sniadecki, Nathan J; Jenkel, Colin F; Vogt, Bryan D; Posner, Jonathan D

    2013-07-21

    In this work, we introduce a simple solvent-assisted micromolding technique for the fabrication of high-fidelity styrene-ethylene/butylene-styrene (SEBS) microfluidic devices with high polystyrene (PS) content (42 wt% PS, SEBS42). SEBS triblock copolymers are styrenic thermoplastic elastomers that exhibit both glassy thermoplastic and elastomeric properties resulting from their respective hard PS and rubbery ethylene/butylene segments. The PS fraction gives SEBS microdevices many of the appealing properties of pure PS devices, while the elastomeric properties simplify fabrication of the devices, similar to PDMS. SEBS42 devices have wettable, stable surfaces (both contact angle and zeta potential) that support cell attachment and proliferation consistent with tissue culture dish substrates, do not adsorb hydrophobic molecules, and have high bond strength to wide range of substrates (glass, PS, SEBS). Furthermore, SEBS42 devices are mechanically robust, thermally stable, as well as exhibit low auto-fluorescence and high transmissivity. We characterize SEBS42 surface properties by contact angle measurements, cell culture studies, zeta potential measurements, and the adsorption of hydrophobic molecules. The PS surface composition of SEBS microdevices cast on different substrates is determined by time-of-flight secondary ion mass spectrometry (ToF-SIMS). The attractive SEBS42 material properties, coupled with the simple fabrication method, make SEBS42 a quality substrate for microfluidic applications where the properties of PS are desired but the ease of PDMS micromolding is favoured. PMID:23670166

  10. Synthesis, Characterization and Adsorption Studies of Sulfonated Poly(Styrene)

    International Nuclear Information System (INIS)

    Poly(styrene) was synthesized by suspension polymerization of styrene. Molar mass of poly(styrene) was determined by viscosity method. Sulfonated poly(styrene) was synthesized by direct sulfonation of poly(styrene) at 40 degree C. These products were identified by using IR spectroscopic technique. Cation exchange properties of sulfonated poly(styrene) have been determined for some metal ions such as Ni/sup 2+/, Zn/sup 2+/, Cu/sup 2+/ and Ca/sup 2+/. The distribution co-efficient and apparent adsorption capacities show that selectivity order of the metals as follow: Ni/sup 2+/ > Zn/sup 2+/ > Cu/sup 2+/ > Ca/sup 2+/. It was found that by increasing the pH of solution, the distribution Co-efficients (Kd) value also increased. (author)

  11. A Study of the Fluorescence Response of Tetraphenyl-butadiene

    OpenAIRE

    Jerry, R.; Winslow, L.(Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139, U.S.A.); Bugel, L.; Conrad, J. M.

    2010-01-01

    Tetraphenyl-butadiene (TPB) is a widely used fluorescent wavelength-shifter. A common application is in liquid-argon-based particle detectors, where scintillation light is produced in the UV at 128 nm. In liquid argon experiments, TPB is often employed to shift the scintillation light to the visible range in order to allow detection via standard photomultiplier tubes. This paper presents studies on the stability of TPB with time under exposure to light. We also examine batch-to-batch variatio...

  12. Scintillation of thin tetraphenyl butadiene films under alpha particle excitation

    CERN Document Server

    Pollmann, Tina; Kuźniak, Marcin

    2010-01-01

    The alpha induced scintillation of the wavelength shifter 1,1,4,4-tetraphenyl-1,3-butadiene (TPB) was studied to improve the understanding of possible surface alpha backgrounds in the DEAP dark matter search experiment. We found that vacuum deposited thin TPB films emit 882 +/-210 photons per MeV under alpha particle excitation. The scintillation pulse shape consists of a double exponential decay with lifetimes of 11 +/-5 ns and 275 +/-10ns.

  13. Effect of Vitamin C on Styrene Induced Respiratory Toxicity

    OpenAIRE

    Tayebeh Pol; Massumeh Ahmadizadeh; Mohamad Boazar

    2011-01-01

    Styrene (ethylbenzene) is widely used as a solvent in many industrial setting. Occupational exposure to ST can result in pulmonary toxicity. For better understanding of the mechanism by which styrene caused lung injury, this study was undertaken to investigate the effect of styrene on rat respiratory epithelial cells. The role of vitamin C (Vit C) on styrene induced toxicity was also investigated. Adult male rats were given ST (ip) at doses of 0, 200, 400 or 600 mg/kg. Another series of rats ...

  14. Styrene polymerization in three-component cationic microemulsions

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Luna, V.H.; Puig, J.E. (Universidad de Guadalajara (Mexico)); Castano, V.M. (Instituto de Fisica (Mexico)); Rodriguez, B.E.; Murthy, A.K.; Kaler, E.W. (Univ. of Delaware, Newark (USA))

    1990-06-01

    The polymerization of styrene in three-component dodecyltrimethylammonium bromide (DTAB) microemulsions is reported. The structure of the unpolymerized microemulsions, determined by conductimetry and quasielastic light scattering (QLS), is consistent with styrene-swollen micelles in equilibrium with regular micelles, both dispersed in an aqueous phase. Polymerization of these transparent microemulsions, monitored by QLS an dilatometry, produced stable, bluish monodisperse microlatices with particle radii ranging from 20 to 30 nm, depending on styrene content. Polymerization initiation appears to occur in the styrene-swollen micelles, and the polymer particles grow by recruiting monomer and surfactant from uninitiated droplets and small micelles.

  15. Conversion of 2,3-butanediol to butadiene

    Energy Technology Data Exchange (ETDEWEB)

    Lilga, Michael A.; Frye, Jr, John G.; Lee, Suh-Jane; Albrecht, Karl O.

    2016-09-06

    A composition comprising 2,3-butanediol is dehydrated to methyl vinyl carbinol and/or 1,3-butadiene by exposure to a catalyst comprising (a) M.sub.xO.sub.y wherein M is a rare earth metal, a group IIIA metal, Zr, or a combination thereof, and x and y are based upon an oxidation state of M, or (b) M.sup.3.sub.a(PO.sub.4).sub.b where M.sup.3 is a group IA, a group IIA metal, a group IIIA metal, or a combination thereof, and a and b are based upon the oxidation state of M.sup.3. Embodiments of the catalyst comprising M.sub.xO.sub.y may further include M.sup.2, wherein M.sup.2 is a rare earth metal, a group IIA metal, Zr, Al, or a combination thereof. In some embodiments, 2,3-butanediol is dehydrated to methyl vinyl carbinol and/or 1,3-butadiene by a catalyst comprising M.sub.xO.sub.y, and the methyl vinyl carbinol is subsequently dehydrated to 1,3-butadiene by exposure to a solid acid catalyst.

  16. Linear Chains of Styrene and Methyl-Styrene Molecules and their Heterojunctions on Silicon: Theory and Experiment

    OpenAIRE

    Kirczenow, George; Piva, Paul G.; Wolkow, Robert A.

    2005-01-01

    We report on the synthesis, STM imaging and theoretical studies of the structure, electronic structure and transport properties of linear chains of styrene and methyl-styrene molecules and their heterojunctions on hydrogen-terminated dimerized silicon (001) surfaces. The theory presented here accounts for the essential features of the experimental STM data including the nature of the corrugation observed along the molecular chains and the pronounced changes in the contrast between the styrene...

  17. The Formation and characteristics of Acrylonitrile/Urea Inclusion Compound

    CERN Document Server

    Zou, Jun-Ting; Pang, Wen-Min; Shi, Lei; Lu, Fei

    2012-01-01

    The formation process and composition of the acrylonitrile/urea inclusion compounds (AN/UIC) with different aging times and AN/urea molar feed ratios are studied by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). It is suggested that DSC could be one of the helpful methods to determine the guest/host ratio and the heat of decomposition. Meanwhile, the guest/host ratio and heat of deformation are obtained, which are 1.17 and 5361.53 J/mol, respectively. It is found that the formation of AN/UIC depends on the aging time. The formation process ends after enough aging time and the composition of AN/UIC becomes stable. It is suggested AN molecules included in urea canal lattice may be packed flat against each other. XRD results reveal that once AN molecules enter urea lattice, AN/UIC are formed, which possess the final structure. When AN molecules are sufficient, the content of AN/UIC increased as aging time prolonging until urea tunnels are saturated by AN.

  18. Lactoperoxidase catalyzes in vitro activation of acrylonitrile to cyanide.

    Science.gov (United States)

    Nasralla, Sherry N; Ghoneim, Asser I; Khalifa, Amani E; Gad, Mohamed Z; Abdel-Naim, Ashraf B

    2009-12-15

    Acrylonitrile (ACN) is a widely used industrial chemical. Although it is a well reported animal carcinogen, its current designation to humans is "possibly carcinogenic". The present study aimed at investigating the ability of LPO enzyme system to oxidize ACN to cyanide (CN(-)) in vitro. Detection of CN(-) served as a marker for the possible generation of free radical intermediates implicated in ACN induced toxicity in the activation process. Optimum conditions for the oxidation of ACN to CN(-) were characterized with respect to pH, temperature and time of incubation as well as ACN, LPO and H(2)O(2) concentrations in incubation mixtures. Maximum reaction velocity (V(max)) and Michaelis-Menten constant (K(m)) were assessed. Addition of nitrite (NO(2)(-)) salts to the reaction mixtures significantly enhanced the rate of the reaction. Free radical scavengers (quercetin and trolox C), LPO enzyme inhibitor (resorcinol) and competitors for LPO binding (sodium azide and indomethacin) were found to reduce the rate of CN(-) production. Inclusion of the sulfhydryl compounds glutathione (GSH), NAC (N-acetylcysteine), D-penicillamine or L-cysteine enhanced the rate of ACN oxidation. The present results demonstrate the ability of LPO enzyme system to oxidize ACN to CN(-) and provide insight for the elucidation of ACN chronic toxicity.

  19. Selective Vulnerability of the Cochlear Basal Turn to Acrylonitrile and Noise

    Directory of Open Access Journals (Sweden)

    B. Pouyatos

    2009-01-01

    Full Text Available Exposure to acrylonitrile, a high-production industrial chemical, can promote noise-induced hearing loss (NIHL in the rat even though this agent does not itself produce permanent hearing loss. The mechanism by which acrylonitrile promotes NIHL includes oxidative stress as antioxidant drugs can partially protect the cochlea from acrylonitrile+noise. Acrylonitrile depletes glutathione levels while noise can increase the formation of reactive oxygen species. It was previously noted that the high-frequency or basal turn of the cochlea was particularly vulnerable to the combined effects of acrylonitrile and noise when the octave band noise (OBN was centered at 8 kHz. Normally, such a noise would be expected to yield damage at a more apical region of the cochlea. The present study was designed to determine whether the basal cochlea is selectively sensitive to acrylonitrile or whether, by adjusting the frequency of the noise band, it would be possible to control the region of the auditory impairment. Rats were exposed to one of three different OBNs centered at different frequencies (4 kHz, 110 dB and 8 or 16 kHz at 97 dB for 5 days, with and without administration of acrylonitrile (50 mg/kg/day. The noise was set to cause limited NIHL by itself. Auditory function was monitored by recording distortion products, by compound action potentials, and by performing cochlear histology. While the ACN-only and noise-only exposures induced no or little permanent auditory loss, the three exposures to acrylonitrile+noise produced similar auditory and cochlear impairments above 16 kHz, despite the fact that the noise exposures covered 2 octaves. These observations show that the basal cochlea is much more sensitive to acrylonitrile+noise than the apical partition. They provide an initial basis for distinguishing the pattern of cochlear injury that results from noise exposure from that which occurs due to the combined effects of noise and a chemical

  20. Performance of CTBN(carboxyl-terminated poly (butadiene-co-acrylonitrile))-EP(diglycidyl ether of bisphenol-A(DGEBA)) Prepolymers and CTBN-EP/polyetheramine (PEA) System

    Institute of Scientific and Technical Information of China (English)

    SHI Minxian; HUANG Zhixiong; LI Yaming; YANG Guorui

    2009-01-01

    CTBN-EP prepolymers were synthesized from CTBN and epoxy resin under the catalysis of HTMAB.FTIR analyses indicate the formation of ester group between the carboxyl group of CTBN and the oxirane group of epoxy resin.The viscosity of modified prepolymer increases with CTBN content increasing,but the epoxy value of the prepolymer decreases greatly.DSC analyses verify that CTBN affects the curing process of CTBN-EP/PEA system.Mechanical testing presents the improved toughness of CTBN-EP/PEA curings for the decrease of tensile strength,flexural strength and compressive strength,and increase of impact strength and elongation-at-break with the CTBN content increasing.SEM micrographs show the rubber phase with many holes in diameter about 0.5-1.5μm is formed when CTBN content is lower than 10 phr.However,the pattern of SEM graph shows some stalactite-like strips when CTBN content is higher than 15 phr.Furthermore,the SEM image of 25 phr CTBN sample forms a kind of co-continuous structure.

  1. 21 CFR 177.1810 - Styrene block polymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Styrene block polymers. 177.1810 Section 177.1810... FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1810 Styrene block polymers. The...

  2. 40 CFR 721.10151 - Modified styrene, divinylbenzene polymer (generic).

    Science.gov (United States)

    2010-07-01

    ... polymer (generic). 721.10151 Section 721.10151 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10151 Modified styrene, divinylbenzene polymer (generic). (a) Chemical... as modified styrene, divinylbenzene polymer (PMN P-07-642) is subject to reporting under this...

  3. 40 CFR 80.55 - Measurement methods for benzene and 1,3-butadiene.

    Science.gov (United States)

    2010-07-01

    ... Measurement methods for benzene and 1,3-butadiene. (a) Sampling for benzene and 1,3-butadiene must be accomplished by bag sampling as used for total hydrocarbons determination. This procedure is detailed in 40 CFR... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Measurement methods for benzene and...

  4. 75 FR 9438 - Americas Styrenics, LLC-Marietta Plant a Subsidiary of Americas Styrenics, LLLC Formerly Known as...

    Science.gov (United States)

    2010-03-02

    ... was published in the Federal Register on January 25, 2010 (75 FR 3937). At the request of the State... engaged in the production of styrene monomer and polystyrene pellets. Information shows that Americas... workers of the subject firm who were adversely affected by increased customer imports of styrene...

  5. Pressure dependence of the Boson peak in poly(butadiene)

    CERN Document Server

    Frick, B

    2002-01-01

    Variation of pressure and temperature in inelastic neutron scattering experiments allows us to separate density and thermal energy contributions. We summarise briefly the influence of pressure and temperature on the dynamic scattering law of the polymer glass former poly(butadiene) far below the glass transition. We also show the advantage of using a liquid-niobium pressure cell in such studies. The effect of pressure on the boson peak is to shift the peak towards higher energies and to reduce the low-frequency modes more strongly below the boson-peak maximum than above. A decrease in the Debye-Waller factor with increasing pressure is observed. (orig.)

  6. Pressure dependence of the Boson peak in poly(butadiene)

    International Nuclear Information System (INIS)

    Variation of pressure and temperature in inelastic neutron scattering experiments allows us to separate density and thermal energy contributions. We summarise briefly the influence of pressure and temperature on the dynamic scattering law of the polymer glass former poly(butadiene) far below the glass transition. We also show the advantage of using a liquid-niobium pressure cell in such studies. The effect of pressure on the boson peak is to shift the peak towards higher energies and to reduce the low-frequency modes more strongly below the boson-peak maximum than above. A decrease in the Debye-Waller factor with increasing pressure is observed. (orig.)

  7. Synthesis and Thermal Properties of Acrylonitrile/Butyl Acrylate/Fumaronitrile and Acrylonitrile/Ethyl Hexyl Acrylate/Fumaronitrile Terpolymers as a Potential Precursor for Carbon Fiber

    OpenAIRE

    Siti Nurul Ain Md Jamil; Rusli Daik; Ishak Ahmad

    2014-01-01

    A synthesis of acrylonitrile (AN)/butyl acrylate (BA)/fumaronitrile (FN) and AN/EHA (ethyl hexyl acrylate)/FN terpolymers was carried out by redox polymerization using sodium bisulfite (SBS) and potassium persulphate (KPS) as initiator at 40 °C. The effect of comonomers, BA and EHA and termonomer, FN on the glass transition temperature (Tg) and stabilization temperature was studied using Differential Scanning Calorimetry (DSC). The degradation behavior and char yield were obtained by Thermog...

  8. Metabolism and toxicity of styrene in microsomal epoxide hydrolase-deficient mice.

    Science.gov (United States)

    Carlson, Gary P

    2010-01-01

    Styrene, which is widely used in manufacturing, is both acutely and chronically toxic to mice. Styrene is metabolized by cytochromes P-450 to the toxic metabolite styrene oxide, which is detoxified via hydrolysis with microsomal epoxide hydrolase (mEH) playing a major role. The purpose of these studies was to characterize the importance of this pathway by determining the hepatotoxicity and pneumotoxicity of styrene in wild-type and mEH-deficient (mEH(-/-)) mice. While the mEH(-/-) mice metabolized styrene to styrene oxide at the same rate as the wild-type mice, as expected there was minimal metabolism of styrene oxide to glycol. mEH(-/-) mice were more susceptible to the lethal effects of styrene. Twenty-four hours following the administration of 200 mg/kg ip styrene, mice demonstrated a greater hepatotoxic response due to styrene, as measured by increased serum sorbitol dehydrogenase activity and greater pneumotoxicity as shown by increased protein levels, cell numbers, and lactate dehydrogenase activity in bronchioalveolar lavage fluid. mEH(-/-) mice were also more susceptible to styrene-induced oxidative stress, as indicated by greater decreases in hepatic glutathione levels 3 h after styrene. Styrene oxide at a dose of 150 mg/kg did not produce hepatotoxicity in either wild-type or mEH(-/-) mice. However, styrene oxide produced pneumotoxicity that was similar in the two strains. Thus, mEH plays an important role in the detoxification of styrene but not for exogenously administered styrene oxide.

  9. Metabolism of styrene to styrene oxide and vinylphenols in cytochrome P450 2F2- and P450 2E1-knockout mouse liver and lung microsomes

    OpenAIRE

    Shen, Shuijie; Li, Lei; Ding, Xinxin; Zheng, Jiang

    2013-01-01

    Pulmonary toxicity of styrene is initiated by cytochromes P450-dependent metabolic activation. P450 2E1 and P450 2F2 are considered to be two main cytochrome P450 (CYP) enzymes responsible for styrene metabolism in mice. The objective of the current study was to determine the correlation between the formation of styrene metabolites (i.e. styrene oxide and 4-vinylphenol) and pulmonary toxicity of styrene, using Cyp2e1- and Cyp2f2-null mouse models. Dramatic decrease in the formation of styrene...

  10. Biocompatibility and characterization of polylactic acid/styrene-ethylene-butylene-styrene composites.

    Science.gov (United States)

    Tsou, Chi-Hui; Kao, Bo-Jyue; Yang, Ming-Chien; Suen, Maw-Cherng; Lee, Yi-Hsuan; Chen, Jui-Chin; Yao, Wei-Hua; Lin, Shang-Ming; Tsou, Chih-Yuan; Huang, Shu-Hsien; De Guzman, Manuel; Hung, Wei-Song

    2015-01-01

    Polylactic acid (PLA)/styrene-ethylene-butylene-styrene (SEBS) composites were prepared by melt blending. Differential scanning calorimetry (DSC) and wide angle X-ray diffraction (WXRD) were used to characterize PLA and PLA/SEBS composites in terms of their melting behavior and crystallization. Curves from thermal gravimetric analysis (TGA) illustrated that thermostability increased with SEBS content. Further morphological analysis of PLA/SEBS composites revealed that SEBS molecules were not miscible with PLA molecules in PLA/SEBS composites. The tensile testing for PLA and PLA/SEBS composites showed that the elongation at the break was enhanced, but tensile strength decreased with increasing SEBS content. L929 fibroblast cells were chosen to assess the cytocompatibility; the cell growth of PLA was found to decrease with increasing SEBS content. This study proposes possible reasons for these properties of PLA/SEBS composites.

  11. Styrene oxide isomerase of Sphingopyxis sp. Kp5.2.

    Science.gov (United States)

    Oelschlägel, Michel; Zimmerling, Juliane; Schlömann, Michael; Tischler, Dirk

    2014-11-01

    Styrene oxide isomerase (SOI) catalyses the isomerization of styrene oxide to phenylacetaldehyde. The enzyme is involved in the aerobic styrene catabolism via side-chain oxidation and allows the biotechnological production of flavours. Here, we reported the isolation of new styrene-degrading bacteria that allowed us to identify novel SOIs. Out of an initial pool of 87 strains potentially utilizing styrene as the sole carbon source, just 14 were found to possess SOI activity. Selected strains were classified phylogenetically based on 16S rRNA genes, screened for SOI genes and styrene-catabolic gene clusters, as well as assayed for SOI production and activity. Genome sequencing allowed bioinformatic analysis of several SOI gene clusters. The isolate Sphingopyxis sp. Kp5.2 was most interesting in that regard because to our knowledge this is the first time it was shown that a member of the family Sphingomonadaceae utilized styrene as the sole carbon source by side-chain oxidation. The corresponding SOI showed a considerable activity of 3.1 U (mg protein)(-1). Most importantly, a higher resistance toward product inhibition in comparison with other SOIs was determined. A phylogenetic analysis of SOIs allowed classification of these biocatalysts from various bacteria and showed the exceptional position of SOI from strain Kp5.2. PMID:25187627

  12. ABSORPTION OF CO2 AND SUBSEQUENT VISCOSITY REDUCTION OF AN ACRYLONITRILE COPOLYMER. (R829555)

    Science.gov (United States)

    Acrylonitrile (AN) copolymers (AN content greater than about 85 mol%) are traditionally solution processed to avoid a cyclization and crosslinking reaction that takes place at temperatures where melt processing would be feasible. It is well known that carbon dioxide (CO

  13. New Star-Branched Poly(acrylonitrile) Architectures : ATRP Synthesis and Solution Properties

    NARCIS (Netherlands)

    Pitto, Valentina; Voit, Brigitte I.; Loontjens, Ton J.A.; Benthem, Rolf A.T.M. van

    2004-01-01

    Atom transfer radical polymerization (ATRP) has been chosen as ‘‘living’’/controlled free radical polymerization system to synthesize a number of novel poly(acrylonitrile) (PAN) architectures. The reaction conditions for the synthesis of linear samples with control over molar mass and molar mass dis

  14. Arylation of Acrylamide and Acrylonitrile with Arenediazonium Salts Catalyzed by Palladium Acetate

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Arylation of acrylamide and acrylonitrile were carried out with various arenediazonium tetrafluoroborates in the presence of a catalytic amount of Pd(OAc)2 in ethanol and a variety of substituted (E)-cinnamamides and (E)-cinnamonitriles were obtained in high yields under mild reaction conditions.

  15. High throughput HPLC-ESI(-)-MS/MS methodology for mercapturic acid metabolites of 1,3-butadiene: Biomarkers of exposure and bioactivation.

    Science.gov (United States)

    Kotapati, Srikanth; Esades, Amanda; Matter, Brock; Le, Chap; Tretyakova, Natalia

    2015-11-01

    1,3-Butadiene (BD) is an important industrial and environmental carcinogen present in cigarette smoke, automobile exhaust, and urban air. The major urinary metabolites of BD in humans are 2-(N-acetyl-L-cystein-S-yl)-1-hydroxybut-3-ene/1-(N-acetyl-L-cystein-S-yl)-2-hydroxybut-3-ene (MHBMA), 4-(N-acetyl-L-cystein-S-yl)-1,2-dihydroxybutane (DHBMA), and 4-(N-acetyl-L-cystein-S-yl)-1,2,3-trihydroxybutyl mercapturic acid (THBMA), which are formed from the electrophilic metabolites of BD, 3,4-epoxy-1-butene (EB), hydroxymethyl vinyl ketone (HMVK), and 3,4-epoxy-1,2-diol (EBD), respectively. In the present work, a sensitive high-throughput HPLC-ESI(-)-MS/MS method was developed for simultaneous quantification of MHBMA and DHBMA in small volumes of human urine (200 μl). The method employs a 96 well Oasis HLB SPE enrichment step, followed by isotope dilution HPLC-ESI(-)-MS/MS analysis on a triple quadrupole mass spectrometer. The validated method was used to quantify MHBMA and DHBMA in urine of workers from a BD monomer and styrene-butadiene rubber production facility (40 controls and 32 occupationally exposed to BD). Urinary THBMA concentrations were also determined in the same samples. The concentrations of all three BD-mercapturic acids and the metabolic ratio (MHBMA/(MHBMA+DHBMA+THBMA)) were significantly higher in the occupationally exposed group as compared to controls and correlated with BD exposure, with each other, and with BD-hemoglobin biomarkers. This improved high throughput methodology for MHBMA and DHBMA will be useful for future epidemiological studies in smokers and occupationally exposed workers. PMID:25727266

  16. Rheology of ABS and binary of organo clay nanocomposites; Reologia de nanocompositos de ABS e mistura binaria de argilas montmorilonita organofilicas

    Energy Technology Data Exchange (ETDEWEB)

    Galvan, Danieli; Mazzucco, Mateus; Carneiro, Fabio; Bartoli, Julio R.; Morales, Ana Rita, E-mail: bartoli@unicamp.br [Fac. de Engenharia Quimica/Universidade Estadual de Campinas-DTP/FEQ/UNICAMP-, SP (Brazil); D' Avila, Marcos A. [Fac. de Engenharia Mecanica/Universidade Estadual de Campinas - DEMA/FEM/UNICAMP, SP (Brazil)

    2011-07-01

    nanocomposites of poly(acrylonitrile-butadiene-styrene) and organically modified montmorillonite clays by melt intercalation on a co-rotating twin-screw extruder were prepared and characterized. It was studied the effects of screw torque and a binary mixture of organically modified montmorillonites on the intercalation/exfoliation of organoclays in the polymer matrix, characterized by X-ray diffraction morphological analyses and by capillary and parallel plates rheological analyses. (author)

  17. Rheology of ABS and binary of organo clay nanocomposites

    International Nuclear Information System (INIS)

    nanocomposites of poly(acrylonitrile-butadiene-styrene) and organically modified montmorillonite clays by melt intercalation on a co-rotating twin-screw extruder were prepared and characterized. It was studied the effects of screw torque and a binary mixture of organically modified montmorillonites on the intercalation/exfoliation of organoclays in the polymer matrix, characterized by X-ray diffraction morphological analyses and by capillary and parallel plates rheological analyses. (author)

  18. WOOD - PLASTIC COMPOSITES FROM WASTE MATERIALS RESULTED IN THE FURNITURE MANUFACTURING PROCESS

    OpenAIRE

    Camelia COŞEREANU; Dumitru LICA

    2014-01-01

    The paper presents the application of waste materials resulted in the furniture manufacturing process as components for wood-plastic composites. The composites are produced from industrial byproducts, such as shavings and ABS (acrylonitrile butadiene styrene), without coupling agent. The two components are derived from industrial processes of furniture manufacturing: the first one consists of wood residues resulted from planing machine as planer shavings, and the second one from ABS edge band...

  19. ECOLOGICAL AND TECHNOLOGICAL ANALYSIS OF MATERIALS FOR 3D-PRINTING

    OpenAIRE

    Є.О. Бовсуновський; Зінченко, Р. О.

    2016-01-01

    The article analyzes the main materials used for 3D-printing. Particular attention is paid to the study of ecological and technological analysis of the effects of the most widely used material: Polylactic Acid and Acrylonitrile Butadiene Styrene, as well as their professional series and Nylon, Polyethylene Terephthalate, TPE on the environment. The article deals with the characteristic features of the physical properties of materials (material) for their intended purpose, according sharing al...

  20. Effects of melt blended poss nanofillers on pom and ABS thermal stability

    OpenAIRE

    Vilà Ramírez, Narciso

    2014-01-01

    This PhD thesis investigated the incorporation of Polyhedral Oligomeric Silsesquioxanes (POSS) in thermoplastic base materials via melt-blending procedures. Particularly, a focus is taken on the enhancement of the thermal resistance through the addition of different types of POSS on two popular engineering plastics known by their low thermal stability, one being a semi-crystalline copolymer i.e. polyoxymethylene (POM) and the other an amorphous copolymer i.e. acrylonitrile butadiene styren...

  1. Three-dimensional heterostructure of metallic nanoparticles and carbon nanotubes as potential nanofiller

    OpenAIRE

    Kim, Whi Dong; Huh, Jun Young; Ahn, Ji Young; Lee, Jae Beom; Lee, Dongyun; Hong, Suck Won; Kim, Soo Hyung

    2012-01-01

    The effect of the dimensionality of metallic nanoparticle-and carbon nanotube-based fillers on the mechanical properties of an acrylonitrile butadiene styrene (ABS) polymer matrix was examined. ABS composite films, reinforced with low dimensional metallic nanoparticles (MNPs, 0-D) and carbon nanotubes (CNTs, 1-D) as nanofillers, were fabricated by a combination of wet phase inversion and hot pressing. The tensile strength and elongation of the ABS composite were increased by 39% and 6%, respe...

  2. Développement des procédés "verts" pour modifier la surface d'ABS avant sa métallisation

    OpenAIRE

    Magallon Cacho, Lorena

    2009-01-01

    The ABS is a copolymer formed by Acrylonitrile-Butadiene-Styrene used in industry whose surface can be coated with a metallic deposit. The traditional process for depositing metallic films in an auto-catalytic way is know as "Electroless", However, this process uses a sulfo-chromic mixture in the preliminary stage of the surface treatment containing Cr (VI) which is a toxic, polluting agent that needs to be replaced. Therefore, it is necessary to develop new surface modification procedures wi...

  3. SOLID WASTE MANAGEMENT IN TABRIZ PETROCHEMICAL COMPLEX

    OpenAIRE

    M. A. Abduli, M. Abbasi, T. Nasrabadi, H. Hoveidi, N. Razmkhah

    2006-01-01

    Tabriz petrochemical complex is located in the northwest of Iran. Major products of this industry include raw plastics like, polyethylene, polystyrene, acrylonitrile, butadiene, styrene, etc. Sources of waste generation include service units, health and cure units, water, power, steam and industrial processes units. In this study, different types of solid waste including hazardous and non hazardous solid wastes were investigated separately. The aim of the study was to focus on the management ...

  4. Microwave Study of Recycled ABS Resins

    Institute of Scientific and Technical Information of China (English)

    A; M; Hasna

    2002-01-01

    This article provides a review of the research unde rt aken in order to determine the suitability of utilizing microwave technology in the production of Recycled ABS Acrylonitrile Butadiene Styrene resin for mouldin gs. The experimental investigation determined the suitability of the existing re cycled ABS material, the mould material used with respect to performance and lon gevity, potential commercial plant and equipment, end mould compression. Introduction Frequency Characterization of ABS The first ...

  5. Smart Card: Turning Point of Technology

    OpenAIRE

    Abhishek Mahajan; Akash Verma; Dhruv Pahuja

    2014-01-01

    A smart card, chip card, or integrated circuit card (icc) is any pocket-sized card with embedded integrated circuits. Smart Cards are secure portable storage devices used for several applications especially security related ones involving access to system’s database either online or offline. Smart cards are made of plastic, generally polyvinyl chloride, but sometimes polyethylene terephthalate based polyesters, acrylonitrile butadiene styrene orpolycarbonate. This research is chie...

  6. Charpy Impact Test on Polymeric Molded Parts

    OpenAIRE

    Alexandra Raicu

    2012-01-01

    The paper presents the Charpy impact tests on the AcrylonitrileButadiene-Styrene (ABS) polymeric material parts. The Charpy impact test, also known as the Charpy V-notch test, is a standardized strain rate test which determines the amount of energy absorbed by a material during fracture. This is a typical method described in ASTM Standard D 6110. We use for testing an Instron - Dynatup equipment which have a fully integrated hardware and software package that let us capture ...

  7. Heck Arylation of Acrylonitrile with Aryl Iodides Catalyzed by a Silica-bound Arsine Palladium(0) Complex

    Institute of Scientific and Technical Information of China (English)

    Ming Zhong CAI; Hong ZHAO; Rong Li ZHANG

    2005-01-01

    Acrylonitrile reacts with aryl iodides in the presence of tri-n-butylamine and a catalytic amount of a silica-bound arsine palladium(0) complex to afford stereoselectively (E)-cinnamonitriles in high yields.

  8. Photodegradation Mechanisms of Tetraphenyl Butadiene Coatings for Liquid Argon Detectors

    CERN Document Server

    Jones, B J P; Conrad, J M; Pla-Dalmau, A

    2013-01-01

    We report on studies of degradation mechanisms of tetraphenyl butadiene (TPB) coatings of the type used in neutrino and dark matter liquid argon experiments. Using gas chromatography coupled to mass spectrometry we have detected the ultraviolet-blocking impurity benzophenone (BP). We monitored the drop in performance and increase of benzophenone concentration in TPB plates with exposure to ultraviolet (UV) light, and demonstrate the correlation between these two variables. Based on the presence and initially exponential increase in the concentration of benzophenone observed, we propose that TPB degradation is a free radical-mediated photooxidation reaction, which is subsequently confirmed by displaying delayed degradation using a free radical inhibitor. Finally we show that the performance of wavelength-shifting coatings of the type envisioned for the LBNE experiment can be improved by 10-20%, with significantly delayed UV degradation, by using a 20% admixture of 4-tert-Butylcatechol.

  9. A Study of the Fluorescence Response of Tetraphenyl-butadiene

    CERN Document Server

    Jerry, R; Bugel, L; Conrad, J M

    2010-01-01

    Tetraphenyl-butadiene (TPB) is a widely used fluorescent wavelength-shifter. A common application is in liquid-argon-based particle detectors, where scintillation light is produced in the UV at 128 nm. In liquid argon experiments, TPB is often employed to shift the scintillation light to the visible range in order to allow detection via standard photomultiplier tubes. This paper presents studies on the stability of TPB with time under exposure to light. We also examine batch-to-batch variations. We compare scintillation-grade TPB to 99% pure TPB response. In the 99% pure samples, we report a yellowing effect, and full degradation of the TPB emission-peak, upon extended exposure to light.

  10. Aging studies on thin tetra-phenyl butadiene films

    Science.gov (United States)

    Acciarri, R.; Canci, N.; Cavanna, F.; Segreto, E.; Szelc, A. M.

    2013-10-01

    Tetra-Phenyl Butadiene (TPB) is the most commonly used compound to wave-shift the 128 nm scintillation light of liquid Argon down to the visible spectrum. We present a study on the loss of conversion efficiency of thin TPB films evaporated on reflective foils when exposed to light and atmosphere. The efficiency of the films is measured and monitored with a dedicated set-up that uses gaseous Argon excited by alpha particles to produce 128 nm photons and working at room temperature. In particular we performed a two years long exposure of the samples to lab diffuse light and atmosphere. We also performed more controlled aging tests to investigate the effect of storing samples in a inert atmosphere.

  11. Photodegradation mechanisms of tetraphenyl butadiene coatings for liquid argon detectors

    Science.gov (United States)

    Jones, B. J. P.; VanGemert, J. K.; Conrad, J. M.; Pla-Dalmau, A.

    2013-01-01

    We report on studies of degradation mechanisms of tetraphenyl butadiene (TPB) coatings of the type used in neutrino and dark matter liquid argon experiments. Using gas chromatography coupled to mass spectrometry we have detected the ultraviolet-blocking impurity benzophenone. We monitored the drop in performance and increase of benzophenone concentration in TPB plates with exposure to ultraviolet (UV) light, and demonstrate the correlation between these two variables. Based on the presence and initially exponential increase in the concentration of benzophenone observed, we propose that TPB degradation is a free radical-mediated photooxidation reaction, which is subsequently confirmed by displaying delayed degradation using a free radical inhibitor. Finally we show that the performance of wavelength-shifting coatings of the type envisioned for the LBNE experiment can be improved by 10-20%, with significantly delayed UV degradation, by using a 20% admixture of 4-tert-Butylcatechol.

  12. Dimedone-catalyzed Addition of Amines into Cyano Group: Facile Synthesis of Thiazol-2-yl Substituted E-Acrylonitriles

    Institute of Scientific and Technical Information of China (English)

    朱伟军; 屠兴超; 冯惠; 屠蔓苏; 姜波; 吴飞跃; 屠树江

    2012-01-01

    An efficient dimedone-catalyzed synthesis of highly functionalized thiazol-2-yl substituted E-acrylonitrile derivatives has been established through two-step reaction of a-thiocyanate ketones with malononitrile and amines. The a-thiocyanate ketones were subjected with malononitrile to provide thiazol-2-ylidenemalononitrile derivatives, followed with various amines in the presence of dimedone to yield the final thiazol-2-yl substituted acrylonitrile derivatives.

  13. Optimization of injection molding parameters for poly(styrene-isobutylene-styrene) block copolymer

    Science.gov (United States)

    Fittipaldi, Mauro; Garcia, Carla; Rodriguez, Luis A.; Grace, Landon R.

    2016-03-01

    Poly(styrene-isobutylene-styrene) (SIBS) is a widely used thermoplastic elastomer in bioimplantable devices due to its inherent stability in vivo. However, the properties of the material are highly dependent on the fabrication conditions, molecular weight, and styrene content. An optimization method for injection molding is herein proposed which can be applied to varying SIBS formulations in order to maximize ultimate tensile strength, which is critical to certain load-bearing implantable applications. The number of injection molded samples required to ascertain the optimum conditions for maximum ultimate tensile strength is limited in order to minimize experimental time and effort. Injection molding parameters including nozzle temperature (three levels: 218, 246, and 274 °C), mold temperature (three levels: 50, 85, and 120 °C), injection speed (three levels: slow, medium and fast) and holding pressure time (three levels: 2, 6, and 10 seconds) were varied to fabricate dumbbell specimens for tensile testing. A three-level L9 Taguchi method utilizing orthogonal arrays was used in order to rank the importance of the different injection molding parameters and to find an optimal parameter setting to maximize the ultimate tensile strength of the thermoplastic elastomer. Based on the Taguchi design results, a Response Surface Methodology (RSM) was applied in order to build a model to predict the tensile strength of the material at different injection parameters. Finally, the model was optimized to find the injection molding parameters providing maximum ultimate tensile strength. Subsequently, the theoretically-optimum injection molding parameters were used to fabricate additional dumbbell specimens. The experimentally-determined ultimate tensile strength of these samples was found to be in close agreement (1.2%) with the theoretical results, successfully demonstrating the suitability of the Taguchi Method and RSM for optimizing injection molding parameters of SIBS.

  14. Review of old chemistry and new catalytic advances in the on-purpose synthesis of butadiene.

    Science.gov (United States)

    Makshina, Ekaterina V; Dusselier, Michiel; Janssens, Wout; Degrève, Jan; Jacobs, Pierre A; Sels, Bert F

    2014-11-21

    Increasing demand for renewable feedstock-based chemicals is driving the interest of both academic and industrial research to substitute petrochemicals with renewable chemicals from biomass-derived resources. The search towards novel platform chemicals is challenging and rewarding, but the main research activities are concentrated on finding efficient pathways to produce familiar drop-in chemicals and polymer building blocks. A diversity of industrially important monomers like alkenes, conjugated dienes, unsaturated carboxylic acids and aromatic compounds are thus targeted from renewable feedstock. In this context, on-purpose production of 1,3-butadiene from biomass-derived feedstock is an interesting example as its production is under pressure by uncertainty of the conventional fossil feedstock. Ethanol, obtained via fermentation or (biomass-generated) syngas, can be converted to butadiene, although there is no large commercial activity today. Though practised on a large scale in the beginning of the 20th century, there is a growing worldwide renewed interest in the butadiene-from-ethanol route. An alternative route to produce butadiene from biomass is through direct carbohydrate and gas fermentation or indirectly via the dehydration of butanediols. This review starts with a brief discussion on the different feedstock possibilities to produce butadiene, followed by a comprehensive summary of the current state of knowledge regarding advances and achievements in the field of the chemocatalytic conversion of ethanol and butanediols to butadiene, including thermodynamics and kinetic aspects of the reactions with discussions on the reaction pathways and the type of catalysts developed. PMID:24993100

  15. Copolymerization of Indene with Acrylic Acid, Itaconic Acid and Acrylonitrile: Characterization and Reactivity Ratios

    International Nuclear Information System (INIS)

    Random copolymers of indene (In) with acrylic acid (AA), itaconic acid (IA) and acrylonitrile (AN) were synthesized by free radical polymerization in dioxane in the presence of azobisisobutyronitrile as an initiator at 60 degree C. The homopolymer of indene and acrylonitrile was prepared using K2MnO4 and sulphuric acid as an initiator, while acrylic acid and itaconic acid were prepared using K2S2O8 solution. The reactivity ratios of the monomers were calculated by different methods. X-ray diffraction as well as thermal analyses were studied. The latter was studied via thermogravimetric analysis and differential thermal analysis. The complexation with metal ions such as Cu+2 and Fe+2 was investigated. The copolymerization and the complexation processes were confirmed by FTIR spectroscopy. Also the activation energy of the prepared copolymers was determined

  16. Nitrilase-catalysed conversion of acrylonitrile by free and immobilized cells of Streptomyces sp.

    Indian Academy of Sciences (India)

    V K Nigam; A K Khandelwal; R K Gothwal; M K Mohan; B Choudhury; A S Vidyarthi; P Ghosh

    2009-03-01

    The biotransformation of acrylonitrile was investigated using thermophilic nitrilase produced from a new isolate Streptomyces sp. MTCC 7546 in both the free and immobilized state. Under optimal conditions, the enzyme converts nitriles to acids without the formation of amides. The whole cells of the isolate were immobilized in agar-agar and the beads so formed were evaluated for 25 cycles at 50°C. The enzyme showed a little loss of activity during reuse. Seventy-one per cent of 0.5 M acrylonitrile was converted to acid at 6 h of incubation at a very low density of immobilized cells, while 100% conversion was observed at 3 h by free cells.

  17. Production of biorenewable styrene: utilization of biomass-derived sugars and insights into toxicity.

    Science.gov (United States)

    Lian, Jieni; McKenna, Rebekah; Rover, Marjorie R; Nielsen, David R; Wen, Zhiyou; Jarboe, Laura R

    2016-05-01

    Fermentative production of styrene from glucose has been previously demonstrated in Escherichia coli. Here, we demonstrate the production of styrene from the sugars derived from lignocellulosic biomass depolymerized by fast pyrolysis. A previously engineered styrene-producing strain was further engineered for utilization of the anhydrosugar levoglucosan via expression of levoglucosan kinase. The resulting strain produced 240 ± 3 mg L(-1) styrene from pure levoglucosan, similar to the 251 ± 3 mg L(-1) produced from glucose. When provided at a concentration of 5 g L(-1), pyrolytic sugars supported styrene production at titers similar to those from pure sugars, demonstrating the feasibility of producing this important industrial chemical from biomass-derived sugars. However, the toxicity of contaminant compounds in the biomass-derived sugars and styrene itself limit further gains in production. Styrene toxicity is generally believed to be due to membrane damage. Contrary to this prevailing wisdom, our quantitative assessment during challenge with up to 200 mg L(-1) of exogenously provided styrene showed little change in membrane integrity; membrane disruption was observed only during styrene production. Membrane fluidity was also quantified during styrene production, but no changes were observed relative to the non-producing control strain. This observation that styrene production is much more damaging to the membrane integrity than challenge with exogenously supplied styrene provides insight into the mechanism of styrene toxicity and emphasizes the importance of verifying proposed toxicity mechanisms during production instead of relying upon results obtained during exogenous challenge. PMID:26803503

  18. Adsorption of Acrylonitrile on Some Soils and Minerals from Aqueous Solutions

    Institute of Scientific and Technical Information of China (English)

    WUDE-YI; N.MATSUE; 等

    1993-01-01

    Equilibrium and kinetic studies have been made on the adsorption of acrylonitrile(CH2=CHCN) on three soils and four minerals from aqueous solutions.It was shown that the organic matter was the major factor affecting the adsorption process in the soils.The conformity of the equilibrium data to linear type(one soil) and Langmuir type(two soils) isotherms indicated that different mechanisms were involved in the adsorption.This behavior appears bo be related to the hydrophobicity of soil organic matter due to their composition and E4/E6 ratio of humic acids.The adsorption kinetics were also different among the soils,indicating the difference in porosity of organic matter among the soils,and the kinetics strongly affected the adsorption capacity of soils for acrylonitrile.Acrylonitrile was slightly adsorbed from aqueous solutions on pyrophyllite with electrically neutral and hydrophobic nature,and practically not on montmorillonite and kaolinite saturated with Ca.However,much higher adsorption occurred on the zeolitized coal ash,probably caused by high organic carbon content(107g/kg).

  19. Acrylonitrile polymerization by Cy3PCuMe and (Bipy)2FeEt2.

    Science.gov (United States)

    Schaper, Frank; Foley, Stephen R; Jordan, Richard F

    2004-02-25

    Cy(3)PCuMe (1) undergoes reversible ligand redistribution at low temperature in solution to form the tight ion pair [Cu(PCy(3))(2)][CuMe(2)] (3). The structure of 3 was assigned on the basis of (i) the stoichiometry of the 1 = 3 equilibrium, (ii) the observation of a triplet for the PCy(3) C1 (13)C NMR resonance due to virtual coupling to two (31)P nuclei, and (iii) reverse synthesis of 1 by combining separately generated Cu(PCy(3))(2)(+) and CuMe(2)(-) ions. Complex 1 and [Cu(PCy(3))(2)][PF(6)] (5) coordinate additional PCy(3) to form (Cy(3)P)(2)CuMe and [Cu(PCy(3))(3)][PF(6)], respectively, while 3 does not. Complex 1, free PCy(3), and (bipy)(2)FeEt(2) (2) each initiate the polymerization of acrylonitrile. In each case, the polyacrylonitrile contains branches that are characteristic of an anionic polymerization mechanism. The major initiator in acrylonitrile polymerization by 1 is PCy(3), which is liberated from 1. A transient iron hydride complex is proposed to initiate acrylonitrile polymerization by 2. PMID:14971946

  20. Radiation Copolymerization of Styrene Monomer Onto Natural Rubber Film

    International Nuclear Information System (INIS)

    Studies on the effect of radiation copolymerization of styrene monomer onto natural rubber film on physical and chemical properties of natural rubber-polystyrene copolymer (NPC) have been done. Natural rubber film firstly immersed in styrene monomer in certain time, then it was wrapped with Mylar film, and then it was irradiated with gamma rays in various doses from 10,25, 50 up to 100 kGy. The styrene monomer content was also varying from 25, 50 and 100 phr (part per hundred part of rubber). Using tensile tester and hardness tester carried out physical characterization of NPC such as modulus-30G, modulus-600, elongation at break, permanent set and hardness. While chemical characterization was carried out by extraction method. The solvent used was acetone and tetrahydrofuran. The experimental results showed that by increasing the styrene monomer at the same irradiation dose, the molecule crosslinked fraction of NPC decreased, while the molecule grafted fraction was increased. But at the saine styrene monomer content, increasing irradiation dose was increasing the molecule crosslinked fraction and decreasing the molecule grafted fraction of NPC. The increasing of molecule crosslinked fraction was effected on the increasing of tensile strength, modulus, hardness, and decreasing of elongation at break of NPC. The tensile strength, modulus, aJId baldness ofNPC were achieved 195 kg/cm2, 108 kg/cm2 and 63 shore respectively at monomer content I00 phr and irradiation dose was 100 kGy

  1. Influence of Cyclodextrin on the Styrene Polymerization

    Institute of Scientific and Technical Information of China (English)

    HU Jie; LIU Bai-ling

    2004-01-01

    Cyclodextrin (CD) are oligosaccharides consisting of 6( α ), 7( β ), 8( γ ) units of1,4-linked glucose. Due to their polar hydrophilic outer shell and relatively hydrophobic cavity, theyare able to build up host-guest complexes by inclusion of suitable hydrophobic molecules. Theformation of these complexes leads to significant changes of the solubility and reactivity of the guestmolecules, but without any chemical modification. Thus, water insoluble molecules may becomecompletely water soluble simply by mixing with an aqueous solution of native CD or CD-derivatives.Hydrogen bonds or hydrophobic interactions are responsible for the stability of the complexes and itturned out that the complexed monomers could be successfully polymerized by free radicalpolymerization in water.In our present work, using styrene as monomer, potassium peroxodisulfate as radical initiator thatreacted in water in the presence ofβ-CD but without any additional surfactant, the effect ofcyclodextrin on the polymerization was described. Additionally, the acceleration mechanism ofcyclodextrin in the polymerization was also explained based on dynamic study.Table 1 Effect of CD on the monomer reactivityIt is found that β -CD could greatly accelerate the polymerization, enhance the final conversion ofmonomer. And the more the amount of β-CD was introduced, the faster the polymerization wasobtained. From Figure 1, after 5 hours reaction at 80℃, the monomer conversion in the presence of1.0g cyclodextrin reached to 95%. However, that in absence of cyclodextrin was only 60%. And themonomer conversion was not to exceed 75% even reacted for 8 hours when no CD in reactionsystem.In order to describe the acceleration of CD in the polymerization quantitatively, based onCD and without CD. As shown in Table 1, CD produced significant effect on the monomer reactivity.The relative relativities of monomer were greatly increased with the increase of the amount of CD.

  2. Principais copolímeros elastoméricos à base de butadieno utilizados na indústria automobilística The most important butadiene based elastomers employed in the automotive industry

    Directory of Open Access Journals (Sweden)

    Tereza C. J. Rocha

    2007-12-01

    Full Text Available Copolímeros elastoméricos à base de butadieno são amplamente utilizados na indústria automobilística. Dentre esses destacam-se os copolímeros de butadieno-estireno (SBR e butadieno-acrilonitrila (NBR. O SBR apresenta maior importância comercial, devido a sua aplicação na produção de pneus. Quando SBR é utilizado juntamente com o homopolímero de butadieno BR-alto cis, excelentes propriedades são obtidas para sua aplicação na banda de rodagem de pneus. O copolímero elastomérico NBR é empregado em artefatos em que é necessária boa resistência a solventes orgânicos e a óleos. Nos últimos anos, as empresas automobilísticas e produtoras de pneumáticos vêm se preocupando com o meio-ambiente e, conseqüentemente, têm investido em novos processos de síntese, mais limpos, para a produção desses elastômeros. Assim, o objetivo deste artigo é apresentar uma revisão sobre dois importantes copolímeros elastoméricos à base de butadieno, SBR e NBR, abordando os processos de síntese, características principais, processamento e aplicações.Elastomer copolymers based on butadiene are widely applied in the automotive industry. Among those copolymers the most important ones are styrene-butadiene (SBR and nitrile-butadiene (NBR. SBR presents higher commercial interest, due to its application in the tire production. When SBR is mixed with high cis-1,4 polybutadiene, excellent properties are attained for application on the pneumatics treads. NBR can be used in a wide variety of application areas requiring oil, fuel, and chemical resistance. In the last years, the automotive and pneumatic industries have been increasingly concerned with environmental issues, and have invested in synthesis processes for elastomers that are less aggressive to the environment. Thus, the purpose of this article is to present a review on two important butadiene elastomer copolymers, SBR and NBR, with emphasis on the polymerization processes. The main

  3. Styrene removal from wate gas by the fungus Exophiala Jeanselmei in a biofilter

    NARCIS (Netherlands)

    Cox, Hubertus Henricus Jacobus

    1995-01-01

    Styrene is an environmental pollutant, emitted in large quantities to the atmosphere by various industrial sectors. Legislation requires industry to reduce the emission of styrene. One option to purify industrial waste gases is biological treatment in biofilters. ... Zie: Summary

  4. Radiation grafting of styrene on starch with high efficiency

    Science.gov (United States)

    Sheikh, N.; Akhavan, A.; Ataeivarjovi, E.

    2013-04-01

    Wheat starch grafted with polystyrene (PS-g-starch) was synthesized via polymerization grafting of styrene on starch by gamma-ray. The effects of starch/styrene weight ratio, and amount of applied doses (5-40 kGy) on the percentage of grafting, G (%), were investigated. The results showed that G (%) increased with increasing starch content. The optimum condition, starch/styrene weight ratio 1/3 and the applied dose 10 kGy, led to 252.9% of grafting. The obtained graft copolymer was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, thermal gravimetric analysis, and scanning electron microscopy. FTIR spectroscopy as well as the XRD analysis exhibited the changes in chemical and crystalline structure of starch after grafting reaction. TGA demonstrated the changes in thermal stability of PS-g-starch copolymer. SEM micrographs indicated porous patches of PS adhering on the starch.

  5. Oxidation of Styrene with Molecular Oxygen in Supercritical CO2

    Institute of Scientific and Technical Information of China (English)

    Tao JIANG; Bu Xing HAN; Guo Ying ZHAO; Zhong Hao LI; Yan Hong CHANG; Hai Xiang GAO; Jun Chun LI

    2004-01-01

    The oxidation of styrene with molecular oxygen catalyzed by PdCl2+CuCl2 has been investigated in supercritical CO2 with a batch reactor. The oxidative system of styrene contains four components at the beginning and seven components during the reaction. The critical temperature, critical pressure, and critical density at different conversions are determined by using a high-pressure view cell. The effect of phase behavior on the conversion and selectivity were studied. Experimental results showed that the critical parameters of the reaction mixture at fixed initial molar ratio changed with the conversion of reactant. The conversion of styrene reached maximum near the critical density of the reaction mixture. Product selectivity also varied with density of reaction mixture and could be tuned to some degree.

  6. Development of Polyclonal Antibodies for the Detection of Styrene Oxide Modified Proteins

    OpenAIRE

    Yuan, Wei; Chung, Jouku; Gee, Shirley; Bruce D Hammock; Zheng, Jiang

    2007-01-01

    Styrene is widely used as one of the most important industrial materials for the production of synthetic rubbers, plastic, insulation, fiberglass, and automobile parts. Inhaled styrene has been reported to produce respiratory toxicity in humans and animals. Styrene oxide, a reactive metabolite of styrene formed via cytochrome P450 enzymes, has been reported to form covalent bonds with proteins, such as albumin and hemoglobin. Among all of the amino acids, cysteine is the most reactive amino a...

  7. Trends in Occupational Exposure to Styrene in the European Glass Fibre-Reinforced Plastics Industry

    OpenAIRE

    Rooij, J.G.M. van; Kasper, A.; Triebig, G; Werner, P.; Jongeneelen, F J; Kromhout, H

    2008-01-01

    Aim: This study presents temporal trends of styrene exposure for workers in the European glass fibre-reinforced plastics (GRP) industry during the period 1966–2002. Methods: Data of personal styrene exposure measurements were retrieved from reports, databases and peer-reviewed papers. Only sources with descriptive statistics of personal measurements were accepted. The styrene exposure data cover personal air samples and biological monitoring data, that is, urinary styrene metabolites (mandeli...

  8. 80 kt/a Styrene Unit Put on Stream at Jinzhou Petrochemical Company

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ The core unit of the 80-kt/a styrene project--the styrene unit was put on stream at the first attempt at Jinzhou Petro-chemical Company, symbolizing the completion of con-struction and startup of the 80 kt/a styrene unit comprised of the styrene section and the ethylbenzene section, the in-vestment in which totals 394 million RMB.

  9. Side chain alkylation of toluene with methanol over basic zeolites - novel production route towards styrene?

    NARCIS (Netherlands)

    Rep, Marco

    2002-01-01

    Styrene is an important monomer for the production of different types of (co-) polymers that are used in, e.g., toys, medical devices, food packaging, paper coatings etc. Styrene is produced with several different industrial processes. In 1998, the production of styrene monomer was approximately 21

  10. 40 CFR 721.9492 - Polymers of styrene, cyclohexyl methacrylate and substituted methacrylate.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polymers of styrene, cyclohexyl... Significant New Uses for Specific Chemical Substances § 721.9492 Polymers of styrene, cyclohexyl methacrylate...) The chemical substances identified generically as polymers of styrene, cyclohexyl methacrylate...

  11. 40 CFR 721.3800 - Formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol, ethylene...

    Science.gov (United States)

    2010-07-01

    ... polyoxyethylene fatty acid, ester with styrenated phenol, ethylene oxide adduct. 721.3800 Section 721.3800... Formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol, ethylene oxide adduct. (a... generically as formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol,...

  12. Conceptual process design of extractive distillation processes for ethylbenzene/styrene separation

    NARCIS (Netherlands)

    Jongmans, M.T.G.; Hermens, E.; Raijmakers, M.; Maassen, J.I.W.; Schuur, B.; Haan, de A.B.

    2012-01-01

    In the current styrene production process the distillation of the close-boiling ethylbenzene/styrene mixture to obtain an ethylbenzene impurity level of 100 ppm in styrene accounts for 75–80% of the energy requirements. The future target is to reach a level of 1–10 ppm, which will increase the energ

  13. 环氧树脂阳离子无皂苯丙乳液用于纸张的表面施胶%Application of Cationic Styrene-Acrylic Emulsion Modified by Epoxy Resin on Surface Sizing

    Institute of Scientific and Technical Information of China (English)

    王西锋; 张光华; 牛恒

    2011-01-01

    以丙烯腈改性淀粉为分散剂,苯乙烯(St)、丙烯酸丁酯(BA)、甲基丙烯酸二甲基氨基乙酯(DM)为单体,丙烯酰胺(AM)为交联单体,环氧树脂(E-44)为功能单体,过硫酸钾(K2S2O3)为引发剂,采用无皂乳液聚合技术合成了一种阳离子苯丙乳液表面施胶剂,并对文化纸进行表面施胶。最佳合成工艺是:w(DM)=3%,m(St):m(BA)=3,w(AM)=4%,w(E=44)=0.3%,w(K2S2O8)=0.5%。%The cationic surface sizing of styrene-acrylic polymers were synthesized by soap-free emulsion technology, using acrylonitrile modified starch as dispersant, dimethylaminoethyl methacrylate, styrene and butyl acrylate as monomers, acrylamide as cross-link

  14. New styrene-b-isobutylene-b-styrene (SIBS) glaucoma drainage implant

    Science.gov (United States)

    Orozco, Marcia A.; Acosta, Ana C.; Espana, Edgar M.; Pinchuk, Leonard; Weber, Bruce; Davis, Stewart; Arrieta, Esdras; Dubovy, Sander; Fantes, Francisco; Aly, Mohamed; Zhou, Yonghua; Parel, Jean-Marie

    2006-02-01

    Purpose: To design and test the Miami-InnFocus Drainage Implant (MiDi) as a glaucoma shunt that is biocompatible, flexible, and significantly smaller than existing commercial implants in order to prevent postoperative hypotony, inflammation, scarring, erosion, and extrusion. Methods: A new biomaterial composed of styrene-b-isobutylene-b-styrene (SIBS) was used in a novel design for a glaucoma drainage implant. The implant consists of a tube 11mm long with an inner diameter of 70, 100, and 150 μm and outer diameter of 250 μm with a 1mm2 tab located 4.5mm from the proximal tip to prevent migration. The device was implanted in 15 New Zealand White rabbits for biocompatibility and efficacy testing. A similarly designed implant made of polydimethylsiloxane was implanted in 6 other animals as a pseudo-control. Typical GDI implantation technique was modified for this device. The proximal end of the new SIBS implant was inserted 2mm into the anterior chamber and the distal end placed in a subconjunctival space created by the surgeon. Biocompatibility of the device was studied by slit-lamp follow-up and intraocular pressure (IOP) measurements recorded periodically. Results: Biocompatibility of the MiDi was excellent. A low and diffuse bleb was observed with these devices. All SIBS tubes were patent 9 months after insertion. Immunostaining demonstrated non-continuous deposition of collagen with virtually no encapsulation. No macrophages or myofibroblast were visible around the SIBS polymer which was found more bioinert than the control PDMS. Conclusion: This newly designed glaucoma implant is clinically biocompatible in the rabbit model and maintained 100% patency at 9 months.

  15. An estimation of photon scattering length in tetraphenyl-butadiene

    Science.gov (United States)

    Stolp, D.; Dalager, O.; Dhaliwal, N.; Godfrey, B.; Irving, M.; Kazkaz, K.; Manalaysay, A.; Neher, C.; Stephenson, S.; Tripathi, M.

    2016-03-01

    Tetraphenyl-butadiene (TPB) is a wavelength shifting material that can absorb ultraviolet photons and emit blue photons. It is used in the detection of vacuum ultraviolet (VUV) photons, for which typical photo-sensors, such as most photomultiplier tubes (PMT) and silicon photomultipliers (SiPM), do not have any quantum efficiency. The secondary blue light is emitted isotropically, however, due to scattering within the material, its angular distribution upon exiting the material can not be easily predicted. Here we describe a procedure for estimating the scattering length of blue light in TPB, by measuring and modeling the angular distribution as a function of layer thickness. The experiment consists of shining 254nm light at various thicknesses of TPB deposited on fused silica, and measuring the intensity of blue light using SiPMs on either side of the sample. We simulate light propagation within the sample to estimate the light yield and compare that to the data, which allows us to estimate mean scattering length for photons in TPB to be in the range 2-3 μm, with some preference for a central value of 2.75 μm.

  16. High performance light-colored nitrile-butadiene rubber nanocomposites.

    Science.gov (United States)

    Lei, Yanda; Guo, Baochun; Chen, Feng; Zhu, Lixin; Zhou, Wenyou; Jia, Demin

    2011-12-01

    High mechanical performance nitrile-butadiene rubber (NBR) with light color was fabricated by the method of in situ formation of zinc disorbate (ZDS) or magnesium disorbate (MDS). The in situ formed ZDS and its polymerization via internal mixing was confirmed by X-ray diffaraction. The mechanical properties, ageing resistance, morphology and the dynamic mechanical analysis were fully studied. It was found that with increasing loading of metallic disorbate both the curing rate and the ionic crosslink density was largely increased. The modulus, tensile strength and tear strength were largely increased. With a comparison between internal mixing and opening mixing, the mechanical performance for the former one was obviously better than the latter one. The high performance was ascribed to the finely dispersion nano domains with irregular shape and obscure interfacial structures. Except for the NBR vulcanizate with a high loading of MDS, the others' ageing resistance with incorporation of these two metallic disorbate was found to be good. Dynamic mechanical analysis (DMA) showed that, with increasing loading of metallic disorbate, the highly increased storage modulus above -20 degrees C, the up-shifted glass transition temperature (Tg) and the reduced mechanical loss were ascribed to strengthened interfacial interactions. PMID:22408977

  17. Secondary organic aerosol formation from the photooxidation of isoprene, 1,3-butadiene, and 2,3-dimethyl-1,3-butadiene under high NOx conditions

    Directory of Open Access Journals (Sweden)

    D. R. Cocker III

    2011-02-01

    Full Text Available Secondary organic aerosol (SOA formation from atmospheric oxidation of isoprene has been the subject of multiple studies in recent years; however, reactions of other conjugated dienes emitted from anthropogenic sources remain poorly understood. SOA formation from the photooxidation of isoprene, isoprene-1-13C, 1,3-butadiene, and 2,3-dimethyl-1,3-butadiene is investigated for high NOx conditions. The SOA yield measured in the 1,3-butadiene/NOx/H2O2 irradiation system (0.089–0.178 was close to or slightly higher than that measured with isoprene under similar NOx conditions (0.077–0.103, suggesting that the photooxidation of 1,3-butadiene is a possible source of SOA in urban air. In contrast, a very small amount of SOA particles was produced in experiments with 2,3-dimethyl-1,3-butadiene. Off-line liquid chromatography – mass spectrometry analysis revealed oligoesters as the major SOA products observed from all dienes investigated. The oligoesters originate from the unsaturated aldehyde gas-phase diene reaction products, which undergo oligoester formation through heterogeneous oxidation under high NOx conditions. Oligoesters produced by the dehydration reaction between nitrooxypolyol and 2-methylglyceric acid monomer or its oligomer were also discovered in these experiments with isoprene as the starting diene. These oligomers are possible sources of the 2-methyltetrols found in ambient aerosol samples collected under high NOx conditions. Furthermore, in low-temperature experiments also conducted in this study, the SOA yield measured with isoprene at 278 K was 2–3 times as high as that measured at 300 K under similar concentration conditions. Although oligomerization plays an important role in SOA formation from isoprene photooxidation, the observed temperature dependence of SOA yield is largely explained by gas/particle partitioning of semi-volatile compounds.

  18. Rich methane laminar flames doped with light unsaturated hydrocarbons. Part II: 1,3butadiene

    CERN Document Server

    Gueniche, Hadj-Ali; Fournet, René; Battin-Leclerc, Frédérique

    2007-01-01

    In line with the study presented in the part I of this paper, the structure of a laminar rich premixed methane flame doped with 1,3-butadiene has been investigated. The flame contains 20.7% (molar) of methane, 31.4% of oxygen and 3.3% of 1,3-butadiene, corresponding to an equivalence ratio of 1.8, and a ratio C4H6 / CH4 of 16 %. The flame has been stabilized on a burner at a pressure of 6.7 kPa using argon as dilutant, with a gas velocity at the burner of 36 cm/s at 333 K. The temperature ranged from 600 K close to the burner up to 2150 K. Quantified species included usual methane C0-C2 combustion products and 1,3-butadiene, but also propyne, allene, propene, propane, 1,2-butadiene, butynes, vinylacetylene, diacetylene, 1,3-pentadiene, 2-methyl-1,3-butadiene (isoprene), 1-pentene, 3-methyl-1-butene, benzene and toluene. In order to model these new results, some improvements have been made to a mechanism previously developed in our laboratory for the reactions of C3-C4 unsaturated hydrocarbons. The main reacti...

  19. Photoreductive degradation of sulfur hexafluoride in the presence of styrene

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Sulfur hexafluoride (SF6) is known as one of the most powerful greenhouse gases in the atmosphere. Reductive photodegradation of SM6 by styrene has been studied with the purpose of developing a novel remediation for sulfur hexafluoride pollution. Effects of reaction conditions on the destruction and removal efficiency (DRE) of SF6 are examined in this study. Both initial styrene-to-SF6 ratio and initial oxygen concentration exert a significant influence on DRE. SF6 removal efficiency reaches a maximum value at the initial styrene-to-SF6 ratio of 0.2. It is found that DRE increases with oxygen concentration over the range of 0 to 0.09 mol/m3 and then decreases with increasing oxygen concentration. When water vapor is fed into the gas mixture, DRE is slightly enhanced over the whole studied time scale. The X-ray Photoelectron Spectroscopy (XPS) analysis, together with gas chromatography-mass spectrometry (GC-MS) and Fourier Transform Infrared spectroscopy (FT-IR) analysis, prove that nearly all the initial fluorine residing in the gas phase is in the form of SiF4, whereas, the initial sulfur is deposited in the form of elemental sulfur, after photodegradation. Free from toxic byproducts, photodegradation in the presence of styrene may serve as a promising technique for SF6 abatement.

  20. 21 CFR 177.1820 - Styrene-maleic anhydride copolymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Styrene-maleic anhydride copolymers. 177.1820 Section 177.1820 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components of Single and Repeated...

  1. Comparing in situ removal strategies for improving styrene bioproduction.

    Science.gov (United States)

    McKenna, Rebekah; Moya, Luis; McDaniel, Matthew; Nielsen, David R

    2015-01-01

    As an important conventional monomer compound, the biological production of styrene carries significant promise with respect to creating novel sustainable materials. Since end-product toxicity presently limits styrene production by previously engineered Escherichia coli, in situ product removal by both solvent extraction and gas stripping were explored as process-based strategies for circumventing its inhibitory effects. In solvent extraction, the addition of bis(2-ethylhexyl)phthalate offered the greatest productivity enhancement, allowing net volumetric production of 836 ± 64 mg/L to be reached, representing a 320 % improvement over single-phase cultures. Gas stripping rates, meanwhile, were controlled by rates of bioreactor agitation and, to a greater extent, aeration. A periodic gas stripping protocol ultimately enabled up to 561 ± 15 mg/L styrene to be attained. Lastly, by relieving the effects of styrene toxicity, new insight was gained regarding subsequent factors limiting its biosynthesis in E. coli and strategies for future strain improvement are discussed. PMID:25034182

  2. Simultaneous production of biobased styrene and acrylates using ethenolysis

    NARCIS (Netherlands)

    Spekreijse, J.; Notre, le J.E.L.; Haveren, van J.; Scott, E.L.; Sanders, J.P.M.

    2012-01-01

    Phenylalanine (1), which could be potentially obtained from biofuel waste streams, is a precursor of cinnamic acid (2) that can be converted into two bulk chemicals, styrene (3) and acrylic acid (4), via an atom efficient pathway. With 5 mol% of Hoveyda–Grubbs 2nd generation catalyst, 1 bar of ethyl

  3. Photoreductive degradation of sulfur hexafluoride in the presence of styrene.

    Science.gov (United States)

    Huang, Li; Gu, Dinghong; Yang, Longyu; Xia, Lanyan; Zhang, Renxi; Hou, Huiqi

    2008-01-01

    Sulfur hexafluoride (SF6) is known as one of the most powerful greenhouse gases in the atmosphere. Reductive photodegradation of SF6 by styrene has been studied with the purpose of developing a novel remediation for sulfur hexafluoride pollution. Effects of reaction conditions on the destruction and removal efficiency (DRE) of SF6 are examined in this study. Both initial styrene-to-SF6 ratio and initial oxygen concentration exert a significant influence on DRE. SF6 removal efficiency reaches a maximum value at the initial styrene-to-SF6 ratio of 0.2. It is found that DRE increases with oxygen concentration over the range of 0 to 0.09 mol/m3 and then decreases with increasing oxygen concentration. When water vapor is fed into the gas mixture, DRE is slightly enhanced over the whole studied time scale. The X-ray Photoelectron Spectroscopy (XPS) analysis, together with gas chromatography-mass spectrometry (GC-MS) and Fourier Transform Infrared spectroscopy (FT-IR) analysis, prove that nearly all the initial fluorine residing in the gas phase is in the form of SiF4, whereas, the initial sulfur is deposited in the form of elemental sulfur, after photodegradation. Free from toxic byproducts, photodegradation in the presence of styrene may serve as a promising technique for SF6 abatement. PMID:18574959

  4. Microstructure and properties of styrene acrylate polymer cement concrete

    NARCIS (Netherlands)

    Zhao Su

    1995-01-01

    The paper systematically describes the evolution of the microstructure of a styrene acrylate polymer cement concrete in relation to its mechanical properties and durability. The results presented and discussed at the present paper involve the interaction of the polymer dispersion with portland cemen

  5. Synthesis and photooxidation of styrene copolymer bearing camphorquinone pendant groups

    Directory of Open Access Journals (Sweden)

    Branislav Husár

    2012-03-01

    Full Text Available (±-10-Methacryloyloxycamphorquinone (MCQ was synthesized from (±-10-camphorsulfonic acid either by a known seven-step synthetic route or by a novel, shorter five-step synthetic route. MCQ was copolymerized with styrene (S and the photochemical behavior of the copolymer MCQ/S was compared with that of a formerly studied copolymer of styrene with monomers containing the benzil (BZ moiety (another 1,2-dicarbonyl. Irradiation (λ > 380 nm of aerated films of styrene copolymers with monomers containing the BZ moiety leads to the insertion of two oxygen atoms between the carbonyl groups of BZ and to the formation of benzoyl peroxide (BP as pendant groups on the polymer backbone. An equivalent irradiation of MCQ/S led mainly to the insertion of only one oxygen atom between the carbonyl groups of camphorquinone (CQ and to the formation of camphoric anhydride (11 covalently bound to the polymer backbone. While the decomposition of pendant BP groups formed in irradiated films of styrene copolymers with pendant BZ groups leads to crosslinking, only small molecular-weight changes in irradiated MCQ/S were observed.

  6. Rich premixed laminar methane flames doped by light unsaturated hydrocarbons. II. 1,3-Butadiene

    Energy Technology Data Exchange (ETDEWEB)

    Gueniche, H.A.; Glaude, P.A.; Fournet, R.; Battin-Leclerc, F. [Departement de Chimie-Physique des Reactions, UMR 7630 CNRS, INPL-ENSIC, 1 rue Grandville, BP 20451, 54001 Nancy Cedex (France)

    2007-10-15

    In line with the study presented in Part I of this paper, the structure of a rich premixed laminar methane flame doped with 1,3-butadiene has been investigated. The flame contains 20.7% (molar) of methane, 31.4% of oxygen, and 3.3% of 1,3-butadiene, corresponding to an equivalence ratio of 1.8, and a C{sub 4}H{sub 6}/CH{sub 4} ratio of 16%. The flame has been stabilized on a burner at a pressure of 6.7 kPa using argon as dilutant, with a gas velocity at the burner of 36 cm/s at 333 K. The temperature ranged from 600 K close to the burner up to 2150 K. Quantified species included the usual methane C{sub 0}-C{sub 2} combustion products and 1,3-butadiene, but also propyne, allene, propene, propane, 1,2-butadiene, butynes, vinylacetylene, diacetylene, 1,3-pentadiene, 2-methyl-1,3-butadiene (isoprene), 1-pentene, 3-methyl-1-butene, benzene, and toluene. To model these new results, some improvements have been made to a mechanism previously developed in our laboratory for the reactions of C{sub 3}-C{sub 4} unsaturated hydrocarbons. The main reaction pathways of consumption of 1,3-butadiene and of formation of C{sub 6} aromatic species have been derived from flow rate analyses. In this case, the C{sub 4} route to benzene formation plays an important role in comparison to the C{sub 3} pathway. (author)

  7. Evaporative emissions of 1,3-butadiene from petrol-fuelled motor vehicles

    Science.gov (United States)

    Ye, Y.; Galbally, I. E.; Weeks, I. A.; Duffy, B. L.; Nelson, P. F.

    This study reports the identification and quantification of 1,3-butadiene in petrol and in the evaporative emissions from Australian light-duty passenger vehicles. The mass fraction of 1,3-butadiene in each of the different grades of any brand of Australian petrol was found to be relatively constant for a given marketing area. However, the mass fractions vary significantly between the different brands (or refineries) from 0.004±0.001% to 0.047±0.008%. The measurements of the evaporative emissions of 1,3-butadiene from in-service motor vehicles were performed using standard Australian Design Rule 37/00 (ADR 37/00) Sealed Housing Evaporative Determination (SHED) tests. For post-1985 catalyst equipped vehicles fuelled with unleaded petrol, average evaporative emissions of 1,3-butadiene were 9.4 (0.7-22) and 5.0 (0.1-23) mg per test for diurnal and hot soak SHED tests, respectively. The corresponding average evaporative emissions for the older, pre-1986 non-catalyst equipped vehicles fuelled with leaded petrol were 26.5 (11.7-45.4) and 9.2 (4.3-13.1) mg per test, respectively, about double the observed emissions from newer vehicles. For the complete vehicle set (all ages), the average mass fraction of 1,3-butadiene in the total hydrocarbon (sum of C 1-C 10 hydrocarbons) emission was 0.21±0.14% from the diurnal phase and was 0.11±0.06% from the hot-soak phase. Evaporative emissions were estimated to contribute about 4% (ranging from 1-15%) of the total (exhaust and evaporative) emissions of 1,3-butadiene from Australian motor vehicles.

  8. ION CONDUCTION IN COMPLEX OF ACRYLONITRILE-COPOLYMERIZED COMB POLYETHER WITH LITHIUM PERCHLORATE

    Institute of Scientific and Technical Information of China (English)

    XU Kang; DENG Zhenghua; WAN Guoxiang

    1991-01-01

    Poly ( oligoether methacrylate- co- acrylonitrile ) s, P ( MEOn- AN ), with oligoether pendants of different lengths were synthesized and the ion conduction property of their Li-salt complexes was studied as the function of polymer structure. At proper copolymer composition, lithium concentration and pendant length, the ion conductivity reaches 7.0×10-5S/cm at ambient temperature, together with improved mechanical strength. The ion transport in the polymer media is assisted by segmental relaxation ,which is confirmed both by the consistency between ion conductivity and Tg and by the study of TSC.

  9. Modification of fiber properties through grafting of acrylonitrile to rayon by chemical and radiation methods

    OpenAIRE

    Inderjeet Kaur; Neelam Sharma; Vandna Kumari

    2013-01-01

    Fibrous properties of rayon has been modified through synthesis of graft copolymers of rayon with acrylonitrile (AN) by chemical method using ceric ammonium nitrate (CAN/HNO3) as a redox initiator and gamma radiation mutual method. Percentage of grafting (Pg) was determined as a function of initiator concentration, monomer concentration, irradiation dose, temperature, time of reaction and the amount of water. Maximum percentage of grafting (160.01%) using CAN/HNO3 was obtained at [CAN] = 22.8...

  10. Deposition of acrylonitrile cluster ions on solid substrates: thin film formation by intracluster polymerization products.

    Science.gov (United States)

    Yoshida, Hiroyuki; Sato, Naoki

    2006-03-01

    Cluster anions of acrylonitrile (AN), known to give intracluster anionic polymerization products, were deposited on solid substrates. The obtained films were examined by using infrared absorption spectroscopy, X-ray photoemission spectroscopy, and gel permeation chromatography with the aid of quantum chemical calculations. The acquired spectroscopic data are similar to those of polyacrylonitrile (PAN), while the normal polymerization of AN or reactions related to PAN seemed not to occur noticeably. On the contrary, the product analysis shows that most of the constituent molecules of the films are formed via cyclohexane-1,3,5-tricarbonitrile (CHTCN), a dominant product of the intracluster polymerization of AN, accompanied by fragmentation and dimerization. PMID:16509718

  11. Simulation of Particle Growth in Gas Phase Polymerization of Butadiene by the Multigrain Model

    Institute of Scientific and Technical Information of China (English)

    孙建中; 赵军子; 何斯征; 周其云

    2001-01-01

    Gas phase polymerization of butadiene by neodymium catalyst was modeled. The effects of mass and heat transfer resistances in the external boundary layer and within particles, sorption of butadiene in polybutadiene,and deactivation of active sites on polymer particle growth and morphology were studied. Simulation results show that the effects of intraparticle mass and heat transfer resistances on the growth rate of polymer particles are insignificant, and that there is no significant effect of mass transfer resistance on the morphology of polymer particles.The simulation results were compared with the experimental results.

  12. Azidated Ether-Butadiene-Ether Block Copolymers as Binders for Solid Propellants

    Science.gov (United States)

    Cappello, Miriam; Lamia, Pietro; Mura, Claudio; Polacco, Giovanni; Filippi, Sara

    2016-07-01

    Polymeric binders for solid propellants are usually based on hydroxyl-terminated polybutadiene (HTPB), which does not contribute to the overall energy output. Azidic polyethers represent an interesting alternative but may have poorer mechanical properties. Polybutadiene-polyether copolymers may combine the advantages of both. Four different ether-butadiene-ether triblock copolymers were prepared and azidated starting from halogenated and/or tosylated monomers using HTPB as initiator. The presence of the butadiene block complicates the azidation step and reduces the storage stability of the azidic polymer. Nevertheless, the procedure allows modifying the binder properties by varying the type and lengths of the energetic blocks.

  13. Morphology-properties relationship on nanocomposite films based on poly(styrene-block-diene-block-styrene copolymers and silver nanoparticles

    Directory of Open Access Journals (Sweden)

    2011-02-01

    Full Text Available A comparative study on the self-assembled nanostructured morphology and the rheological and mechanical properties of four different triblock copolymers, based on poly(styrene-block-diene-block-styrene and poly(styrene-block-diene-block-styrene matrices, and of their respective nanocomposites with 1 wt% silver nanoparticles, is reported in this work. In order to obtain well-dispersed nanoparticles in the block copolymer matrix, dodecanethiol was used as surfactant, showing good affinity with both nanoparticles and the polystyrene phase of the matrices as predicted by the solubility parameters calculated based on Hoftyzer and Van Krevelen theory. The block copolymer with the highest PS content shows the highest tensile modulus and tensile strength, but also the smallest elongation at break. When silver nanoparticles treated with surfactant were added to the block copolymer matrices, each system studied shows higher mechanical properties due to the good dispersion and the good interface of Ag nanoparticles in the matrices. Furthermore, it has been shown that semiempirical models such as Guth and Gold equation and Halpin-Tsai model can be used to predict the tensile modulus of the analyzed nanocomposites.

  14. Synthesis and Properties of Styrene Butadiene Impact Resin%丁苯抗冲树脂偶合规律的研究

    Institute of Scientific and Technical Information of China (English)

    黄军左; 陈英林; 陈磊; 郭永华; 苏积蝉

    2007-01-01

    以苯乙烯、丁二烯为单体,正丁基锂(n-BuLi)为引发剂,环己烷/正己烷为溶剂,环氧大豆油为偶联剂,通过阴离子聚合和偶合反应,研究了偶联剂的用量、偶合温度、偶合时间、偶联剂的加料次数等对偶合效率的影响,结果表明适宜的偶合温度为70℃~80℃,适宜的偶合时间为10min;并结合偶联剂的分子结构对环氧大豆油的偶合机理进行了探讨.

  15. 丙烯酰氯偶联活性丁苯共聚物%Coupling reaction of living butadiene-styrene copolymers coupled with acryloyl chloride

    Institute of Scientific and Technical Information of China (English)

    徐日炜; 焦书科; 余鼎声; 张兴英; 侯元雪; 张洪敏

    2002-01-01

    以n-BuLi为引发剂,四氢呋喃(THF)为调节剂,环己烷为溶剂,采用丙烯酰氯为偶联剂对丁二烯-苯乙烯阴离子共聚体系进行偶联反应,详细考察了影响偶联反应的各种因素,如偶联剂用量、分子量、偶联反应时间、偶联反应温度、THF用量、末端基团、单体浓度等.结果表明,制备有较高相对臂数和偶联效率的溶液丁苯(SSBR)的偶联反应条件为[AC]/[BuLi]=0.7~5 (摩尔比),反应温度在50~60 ℃,反应时间60 min,THF/Li≤50(摩尔比),单体含量为12%(质量分数).

  16. Plant Growth and Water Purification of Porous Vegetation Concrete Formed of Blast Furnace Slag, Natural Jute Fiber and Styrene Butadiene Latex

    Directory of Open Access Journals (Sweden)

    Hwang-Hee Kim

    2016-04-01

    Full Text Available The purpose of this study is to investigate porous vegetation concrete formed using the industrial by-products blast furnace slag powder and blast furnace slag aggregates. We investigated the void ratio, compressive strength, freeze–thaw resistance, plant growth and water purification properties using concretes containing these by-products, natural jute fiber and latex. The target performance was a compressive strength of ≥12 MPa, a void ratio of ≥25% and a residual compressive strength of ≥80% following 100 freeze–thaw cycles. Using these target performance metrics and test results for plant growth and water purification, an optimal mixing ratio was identified. The study characterized the physical and mechanical properties of the optimal mix, and found that the compressive strength decreased compared with the default mix, but that the void ratio and the freeze–thaw resistance increased. When latex was used, the compressive strength, void ratio and freeze–thaw resistance all improved, satisfying the target performance metrics. Vegetation growth tests showed that plant growth was more active when the blast furnace slag aggregate was used. Furthermore, the use of latex was also found to promote vegetation growth, which is attributed to the latex forming a film coating that suppresses leaching of toxic components from the cement. Water purification tests showed no so significant differences between different mixing ratios; however, a comparison of mixes with and without vegetation indicated improved water purification in terms of the total phosphorus content when vegetation had been allowed to grow.

  17. Removal of styrene from waste gas stream using a biofilter

    Directory of Open Access Journals (Sweden)

    B Bina

    2004-12-01

    Full Text Available Background: Styrene is produced in large quantities in the chemical industries and it has been listed among the 189 hazardous and toxic atmospheric contaminants under Clean Air Act Amendments, 1990, due to its adverse effects on human health. The biofiltration has been widely and efficiently applied during recent decades for the treatment of air streams contaminated by volatile organic compounds at low concentrations. Also this technology has been applied widely and efficiently in the removal of styrene from waste gas streams. Methods: Biofiltration of waste gas stream polluted by styrene vapor was investigated in a three-stage bench scale reactor. Yard waste compost using shredded hard plastics as a bulking agent in a 75:25 v/v mix of plastics:compost was used to packing biofilter. The system inoculation was achieved by adding thickened activated sludge obtained from municipal wastewater treatment plant and the effects of loading rate, inlet concentration, and empty bed retention time variations on the performance and operation of biofilter were studied. Results: Microbial acclimation to styrene was achieved with inlet concentration of 65 ± 11 ppm and bed contact time of 360 s after 57 days of operation. Under steady state conditions experimental results showed equal average removal efficiency of about 84% at loading rates of 60 and 80 g m-3 h-1 with empty bed retention time of 60 s. Maximum elimination capacity was obtained up to 81 g m-3 h-1 with organic loading rate of about 120 g m-3 h-1. Reduction in performance was observed at inlet concentrations of upper than 650 ppm related to organic loading rates up to 160 g m-3 h-1 and then removal efficiency was decreased sharply. Evaluation of the concentration profile along the bed height of column indicated that the most value of elimination capacity occurred in the first section of biofilter. Elimination capacity also showed higher performance when empty bed retention time was reduced to 30 s

  18. Theoretical study on the gas phase reaction of acrylonitrile with a hydroxyl radical.

    Science.gov (United States)

    Sun, Jingyu; Wang, Rongshun; Wang, Baoshan

    2011-10-01

    The mechanism and kinetics of the reaction of acrylonitrile (CH(2)=CHCN) with hydroxyl (OH) has been investigated theoretically. This reaction is revealed to be one of the most significant loss processes of acrylonitrile. BHandHLYP and M05-2X methods are employed to obtain initial geometries. The reaction mechanism conforms that OH addition to C[double bond, length as m-dash]C double bond or C atom of -CN group to form the chemically activated adducts, 1-IM1(HOCH(2)=CHCN), 2-IM1(CH(2)=HOCHCN), and 3-IM1(CH(2)=CHCOHN) via low barriers, and direct hydrogen abstraction paths may also occur. Temperature- and pressure-dependent rate constants have been evaluated using the Rice-Ramsperger-Kassel-Marcus theory. The calculated rate constants are in good agreement with the experimental data. At atmospheric pressure with N(2) as bath gas, 1-IM1(OHCH(2)=CHCN) formed by collisional stabilization is the major product in the temperature range of 200-1200 K. The production of CH(2)CCN and CHCHCN via hydrogen abstractions becomes dominant at high temperatures (1200-3000 K).

  19. Crystallization analysis fractionation of poly(ethylene-co-styrene) produced by metallocene catalysts

    KAUST Repository

    Kamal, Muhammad Shahzad

    2013-06-06

    Ethylene homo polymer and ethylene-styrene copolymers were synthesized using Cp2ZrCl2 (1)/methyl aluminoxane (MAO) and rac-silylene-bis (indenyl) zirconium dichloride (2)/MAO catalyst systems by varying styrene concentration and reaction conditions. Crystallization analysis fractionation (CRYSTAF), DSC, FTIR and 1H NMR spectroscopy were used for characterizing the synthesized polymers. Interestingly, styrene was able to increase the activity of 1/MAO and 2/MAO catalyst systems at low concentrations, but at higher concentrations the activity decreases. The 1/MAO system at low and high pressure was unable to incorporate styrene, and the final product was pure polyethylene. On the other hand, with 2/MAO polymerization of ethylene and styrene yielded copolymer containing both styrene and ethylene. Results obtained from CRYSTAF and DSC reveal that on using 1/MAO system at high pressure, the resulting polymer in the presence of styrene has similar crystallinity as the polymer produced without styrene. Using both 1/MAO at low pressure and 2/MAO leads to decrease in crystallinity with increase in styrene concentration, even though the former does not incorporate styrene. © 2013 Springer-Verlag Berlin Heidelberg.

  20. Grafting of diethyl maleate and maleic anhydride onto styrene-b-(ethylene-co-1-butene)-b-styrene triblock copolymer (SEBS)

    NARCIS (Netherlands)

    Picchioni, F.; Ghetti, S.; Passaglia, E.; Ruggeri, G.

    2000-01-01

    In this paper a study of the bulk functionalization of styrene-b-(ethylene-co-1-butene)-b-styrene triblock copolymer (SEBS) with diethyl maleate (DEM) or maleic anhydride (MAH) and dicumyl peroxide (DCP) as initiator in a Brabender mixer is described. The determination of the functionalization degre

  1. Ternary Ag/MgO-SiO2 catalysts for the conversion of ethanol into butadiene.

    Science.gov (United States)

    Janssens, Wout; Makshina, Ekaterina V; Vanelderen, Pieter; De Clippel, Filip; Houthoofd, Kristof; Kerkhofs, Stef; Martens, Johan A; Jacobs, Pierre A; Sels, Bert F

    2015-03-01

    Ternary Ag/Magnesia-silica catalysts were tested in the direct synthesis of 1,3-butadiene from ethanol. The influence of the silver content and the type of silica source on catalytic performance has been studied. Prepared catalysts were characterized by (29) Si NMR, N2 sorption, small-angle X-ray scattering measurements, XRD, environmental scanning electron microscopy with energy dispersive X-ray analysis (ESEM/EDX), FTIR spectroscopy of adsorbed pyridine and CO2 , temperature-programmed desorption of CO2 and UV/Vis diffuse reflectance spectroscopy. Based on these characterization results, the catalytic performance of the catalysts in the 1,3-butadiene formation process was interpreted and a tentative model explaining the role of the different catalytically active sites was elaborated. The balance of the active sites is crucial to obtain an active and selective catalyst to form 1,3-butadiene from ethanol. The optimal silver loading is 1-2 wt% on a MgO-silica support with a molar Mg/Si ratio of 2. The silver species and basic sites (Mg−O pairs and basic OH groups) are of prime importance in the 1,3-butadiene production, catalyzing mainly the ethanol dehydrogenation and the aldol condensation, respectively. PMID:25410420

  2. HYDROXYL RADICAL AND OZONE INITIATED PHOTOCHEMICAL REACTIONS OF 1,3-BUTADIENE. (R826247)

    Science.gov (United States)

    1,3-Butadiene, classified as hazardous in the 1990 Clean Air Act Amendments, is an important ambient air pollutant. Understanding its atmospheric transformation is useful for its own sake, and is also helpful for eliciting isoprene's fate in the atmosphere (isoprene dominates ...

  3. Ultrasonic velocity and absorption study of binary mixtures of cyclohexane with acrylonitrile by interferometric method at different frequencies

    Science.gov (United States)

    Pawar, N. R.; Chimankar, O. P.; Bhandakkar, V. D.; Padole, N. N.

    2012-12-01

    The ultrasonic velocity (u), absorption (α), density (ρ), and viscosity (η) has been measured at different frequencies (1MHz to 10MHz) in the binary mixtures of cyclohexane with acrylonitriile over the entire range of composition at temperature 303K. Vander Waal's constant (b), adiabatic compressibility (βa), acoustic impedance (Z), molar volume (V), free length (Lf), free volume, internal pressure, intermolecular radius and relative association have been also calculated. A special application for acrylonitrile is in the manufacture of carbon fibers. These are produced by paralysis of oriented poly acrylonitrile fibers and are used to reinforce composites for high-performance applications in the aircraft, defense and aerospace industries. Other applications of acrylonitrile are in the production of fatty amines, ion exchange resins and fatty amine amides used in cosmetics, adhesives, corrosion inhibitors and water-treatment resins. Cyclohexane derivatives can be used for the synthesis of pharmaceuticals, dyes, herbicides, plant growth regulator, plasticizers, rubber chemicals, nylon, cyclamens and other organic compounds. In the view of these extensive applications of acrylonitrile and cyclohexane in the engineering process, textile and pharmaceutical industries present study provides qualitative information regarding the nature and strength of interaction in the liquid mixtures through derive parameters from ultrasonic velocity and absorption measurement.

  4. Ultrasonic velocity and absorption study of binary mixtures of cyclohexane with acrylonitrile by interferometric method at different frequencies

    International Nuclear Information System (INIS)

    The ultrasonic velocity (u), absorption (α), density (ρ), and viscosity (η) has been measured at different frequencies (1MHz to 10MHz) in the binary mixtures of cyclohexane with acrylonitriile over the entire range of composition at temperature 303K. Vander Waal's constant (b), adiabatic compressibility (βa), acoustic impedance (Z), molar volume (V), free length (Lf), free volume, internal pressure, intermolecular radius and relative association have been also calculated. A special application for acrylonitrile is in the manufacture of carbon fibers. These are produced by paralysis of oriented poly acrylonitrile fibers and are used to reinforce composites for high-performance applications in the aircraft, defense and aerospace industries. Other applications of acrylonitrile are in the production of fatty amines, ion exchange resins and fatty amine amides used in cosmetics, adhesives, corrosion inhibitors and water-treatment resins. Cyclohexane derivatives can be used for the synthesis of pharmaceuticals, dyes, herbicides, plant growth regulator, plasticizers, rubber chemicals, nylon, cyclamens and other organic compounds. In the view of these extensive applications of acrylonitrile and cyclohexane in the engineering process, textile and pharmaceutical industries present study provides qualitative information regarding the nature and strength of interaction in the liquid mixtures through derive parameters from ultrasonic velocity and absorption measurement.

  5. Secondary organic aerosol formation from the photooxidation of isoprene, 1,3-butadiene, and 2,3-dimethyl-1,3-butadiene under high NOx conditions

    Directory of Open Access Journals (Sweden)

    D. R. Cocker III

    2011-07-01

    Full Text Available Secondary organic aerosol (SOA formation from atmospheric oxidation of isoprene has been the subject of multiple studies in recent years; however, reactions of other conjugated dienes emitted from anthropogenic sources remain poorly understood. SOA formation from the photooxidation of isoprene, isoprene-1-13C, 1,3-butadiene, and 2,3-dimethyl-1,3-butadiene is investigated for high NOx conditions. The SOA yield measured in the 1,3-butadiene/NOx/H2O2 irradiation system (0.089–0.178 was close to or slightly higher than that measured with isoprene under similar NOx conditions (0.077–0.103, suggesting that the photooxidation of 1,3-butadiene is a possible source of SOA in urban air. In contrast, a very small amount of SOA particles was produced in experiments with 2,3-dimethyl-1,3-butadiene. Off-line liquid chromatography – mass spectrometry analysis revealed that the signals of oligoesters comprise a major fraction (0.10–0.33 of the signals of the SOA products observed from all dienes investigated. The oligoesters originate from the unsaturated aldehyde gas phase diene reaction products; namely, semi-volatile compounds produced by the oxidation of the unsaturated aldehyde undergo particle-phase oligoester formation. Oligoesters produced by the dehydration reaction between nitrooxypolyol and 2-methylglyceric acid monomer or its oligomer were also characterized in these experiments with isoprene as the starting diene. These oligomers are possible sources of the 2-methyltetrols found in ambient aerosol samples collected under high NOx conditions. Furthermore, in low-temperature experiments also conducted in this study, the SOA yield measured with isoprene at 278 K was 2–3 times as high as that measured at 300 K under similar concentration conditions. Although oligomerization plays an important role in SOA formation from isoprene photooxidation, the observed temperature dependence of SOA yield is largely explained by gas/particle partitioning

  6. Emission of 1,3-butadiene from petrol-driven motor vehicles

    Science.gov (United States)

    Ye, Y.; Galbally, I. E.; Weeks, I. A.

    This study reports the measurement of 1,3-butadiene emissions from 30 petrol-driven vehicles from the Australian car fleet using the Australian Design Rule 37/00 vehicle test procedure. Six of the cars tested were not equipped with catalytic converters and used leaded petrol as fuel. The remaining 24 cars were fitted with catalytic converters and used unleaded petrol. 1,3-Butadiene in exhaust samples was found to degrade rapidly in SUMMA treated stainless steel canisters and the degradation followed first-order kinetics. The rate coefficient of the decay can be represented by a linear dependence on the concentration of nitrogen oxides in the exhaust ( r2 = 0.79, n = 43), and the gas-phase reaction of NO 2 and 1,3-butadiene may have a major role in this loss. The 1,3-butadiene concentrations used to estimate vehicle emissions were corrected for this loss using the decay rate constant either observed from replicate analyses or from the NO x concentrations in the samples. The measurements showed that 1,3-butadiene was emitted at a rate of 20.7 ± 9.2 mg km -1 from 6 non-catalyst vehicles. There was considerable scatter in the observations from catalyst equipped vehicles and we infer that this was due to the malfunction of the emission control devices on some vehicles. The 19 vehicles that appeared to have functioning catalyst emission control devices had an average emission rate of 2.1 ± 1.5 mg km -1. These emission rates are consistent with atmospheric observations and are much higher than those reported previously. We calculate that more than 90% of the 1,3-butadiene in engine exhaust comes from the common alkane and aromatic constituents of the fuel. A comparison of emissions in the different phases of the drive cycle indicates that current emission controls remove more than 90% of the 1,3-butadiene from the initial exhaust mixture.

  7. Effect of ultrasonic pretreatment on emulsion polymerization of styrene.

    Science.gov (United States)

    Nagatomo, Daichi; Horie, Takafumi; Hongo, Chizuru; Ohmura, Naoto

    2016-07-01

    This study investigated the effect of pretreatment of ultrasonic irradiation on emulsion polymerization of styrene to propose a process intensification method which gives high conversion, high reaction rate, and high energy efficiency. The solution containing styrene monomer was irradiated by a horn mounted on the ultrasonic transducer with the diameter of 5mm diameter and the frequency of 28 kHz before starting polymerization. The pretreatment of ultrasound irradiation as short as 1 min drastically improved monomer dispersion and increased reaction rate even under the agitation condition with low rotational speed of impeller. Furthermore, the ultrasonic pretreatment resulted in higher monomer concentration in polymer particles and produced larger polymer particles than conventional polymerization without ultrasonic pretreatment.

  8. Effect of ultrasonic pretreatment on emulsion polymerization of styrene.

    Science.gov (United States)

    Nagatomo, Daichi; Horie, Takafumi; Hongo, Chizuru; Ohmura, Naoto

    2016-07-01

    This study investigated the effect of pretreatment of ultrasonic irradiation on emulsion polymerization of styrene to propose a process intensification method which gives high conversion, high reaction rate, and high energy efficiency. The solution containing styrene monomer was irradiated by a horn mounted on the ultrasonic transducer with the diameter of 5mm diameter and the frequency of 28 kHz before starting polymerization. The pretreatment of ultrasound irradiation as short as 1 min drastically improved monomer dispersion and increased reaction rate even under the agitation condition with low rotational speed of impeller. Furthermore, the ultrasonic pretreatment resulted in higher monomer concentration in polymer particles and produced larger polymer particles than conventional polymerization without ultrasonic pretreatment. PMID:26964957

  9. Styrene-based shape memory foam: fabrication and mathematical modeling

    Science.gov (United States)

    Yao, Yongtao; Zhou, Tianyang; Qin, Chao; Liu, Yanju; Leng, Jinsong

    2016-10-01

    Shape memory polymer foam is a promising kind of structure in the biomedical and aerospace field. Shape memory styrene foam with uniform and controlled open-cell structure was successfully fabricated using a salt particulate leaching method. Shape recovery capability exists for foam programming in both high-temperature compression and low-temperature compression (Shape recovery properties such as shape fixing property and shape recovery ratio were also characterized. In order to provide guidance for the future fabrication of shape memory foam, the theories of Gibson and Ashby as well as differential micromechanics theory were applied to predict Young’s modulus and the mechanical behavior of SMP styrene foams during the compression process.

  10. SYNDIOSPECIFIC POLYMERIZATION OF STYRENE WITH MULTI-NUCLEAR TITANIUM COMPLEXES

    Institute of Scientific and Technical Information of China (English)

    Jie Chen; Jing-yu Liu; Yan-guo Li; Yue-sheng Li

    2007-01-01

    Two multi-nuclear titanium complexes [Ti(η5-Cp*)Cl(μ-O)]3 (1) and [(η5-Cp*TiCl)(μ-O)2(η5-Cp*Ti)2(μ-O)(μ-O)2]2Ti (Cp* = C5Me5) (2) have been investigated as the precatalysts for syndiospecific polymerization of styrene. In the presence of modified methylaluminoxane (MMAO) as a cocatalyst, complexes 1 and 2 display much higher catalytic activities towards styrene polymerization, and produce the higher molecular weight polystyrenes with higher syndiotacticities and melting temperatures (Tm) than the mother complex Cp*TiCl3 does when the polymerization temperature is above 70℃and the Al/Ti molar ratio is in the low range especially.

  11. Interacting Blends of Novel Unsaturated Polyester Amide Resin with Styrene

    OpenAIRE

    Hasmukh S. Patel; Panchal, Kumar K.

    2004-01-01

    Novel unsaturated poly (ester-amide) resins (UPEAs) were prepared by the reaction between an epoxy resin, namely diglycidyl ether of bisphenol–A (DGEBA) and unsaturated aliphatic bisamic acids using a base catalyst. These UPEAs were then blended with a vinyl monomer namely, Styrene (STY.) to produce a homogeneous resin syrup. The curing of these UPEAs-STY. resin blends was carried out by using benzoyl peroxide (BPO) as a catalyst and was monitored by using a differential scanning calorimeter ...

  12. Electrochemical Dicarboxylation of Styrene: Synthesis of 2-Phenylsuccinic Acid

    Institute of Scientific and Technical Information of China (English)

    WANG, Huan; LIN, Mei-Yu; FANG, Hui-Jue; CHEN, Ting-Ting; LU, Jia-Xing

    2007-01-01

    Electrochemical dicarboxylation of styrene in the presence of atmospheric pressure of CO2 with a Ti cathode monium bromide to give 2-phenylsuccinic acid. Influences of the nature of the electrodes, the current density, the passed charge and the temperature on electrolysis were studied to optimize the electrolytic conditions, with the maximal isolated yield to be 86.07%. The mechanism of the elelctrocarboxylation process has been studied by cyclic voltammetry.

  13. Grafting titanium nitride surfaces with sodium styrene sulfonate thin films

    OpenAIRE

    Zorn, Gilad; MIGONNEY, Véronique; Castner, David G.

    2014-01-01

    The importance of titanium nitride lies in its high hardness and its remarkable resistance to wear and corrosion, which has led to its use as a coating for the heads of hip prostheses, dental implants and dental surgery tools. However, the usefulness of titanium nitride coatings for biomedical applications could be significantly enhanced by modifying their surface with a bioactive polymer film. The main focus of the present work was to graft a bioactive poly(sodium styrene sulf...

  14. MAGNETIC FIELD EFFECT ON PHOTOPOLYMERIZATION OF STYRENE MICROEMULSION

    Institute of Scientific and Technical Information of China (English)

    CHEN Yonglie; Anders Hult; Bengt Ranby

    1993-01-01

    External magnetic field increases the photo-induced polymerization rate of styrene microemulsion. The type of photoinitiator plays an important role. The photoinitiators used are dimethoxyphenyl acetophenone(DMPA), 1-hydroxycyclohexyl phenylketone ( Irgacure 184) and dimethylhydroxyacetophenone ( Darocur 1173 ). No magnetic effect was observed by using dibenzylketone (DBK) as photoinitiator. The molecular weight of the polymer is slightly affected by magnetic field. The influence of temperature has also been investigated.

  15. Styrene biofiltration in a trickle-bed reactor

    Directory of Open Access Journals (Sweden)

    V. Novak

    2008-04-01

    Full Text Available The biological treatment of styrene waste gas in a trickle-bed filter (TBF was investigated. The bioreactor consisted of a two-part glass cylinder (ID 150 mm filled with 25 mm polypropylene Pall rings serving as packing material. The bed height was 1m. Although the laboratory temperature was maintained at 22 ºC, the water temperature in the trickle-bed filter was slightly lower (about 18 ºC.The main aim of our study was to observe the effect of empty-bed residence time (EBRT on bioreactor performance at a constant pollutant concentration over an extended time period. The bioreactor was inoculated with a mixed microbial consortium isolated from a styrene-degrading biofilter that had been running for the previous two years. After three weeks of acclimation period, the bioreactor was loaded with styrene (100 mg.m-3. EBRT was in the range of 53 s to 13 s. A maximum elimination capacity (EC of 11.3 gC.m-3.h-1 was reached at an organic loading (OL rate of 18.6 gC.m-3.h-1.

  16. A preliminary regional PBPK model of lung metabolism for improving species dependent descriptions of 1,3-butadiene and its metabolites.

    Science.gov (United States)

    Campbell, Jerry; Van Landingham, Cynthia; Crowell, Susan; Gentry, Robinan; Kaden, Debra; Fiebelkorn, Stacy; Loccisano, Anne; Clewell, Harvey

    2015-08-01

    1,3-Butadiene (BD), a volatile organic chemical (VOC), is used in synthetic rubber production and other industrial processes. It is detectable at low levels in ambient air as well as in tobacco smoke and gasoline vapors. Inhalation exposures to high concentrations of BD have been associated with lung cancer in both humans and experimental animals, although differences in species sensitivity have been observed. Metabolically active lung cells such as Pulmonary Type I and Type II epithelial cells and club cells (Clara cells)(1) are potential targets of BD metabolite-induced toxicity. Metabolic capacities of these cells, their regional densities, and distributions vary throughout the respiratory tract as well as between species and cell types. Here we present a physiologically based pharmacokinetic (PBPK) model for BD that includes a regional model of lung metabolism, based on a previous model for styrene, to provide species-dependent descriptions of BD metabolism in the mouse, rat, and human. Since there are no in vivo data on BD pharmacokinetics in the human, the rat and mouse models were parameterized to the extent possible on the basis of in vitro metabolic data. Where it was necessary to use in vivo data, extrapolation from rat to mouse was performed to evaluate the level of uncertainty in the human model. A kidney compartment and description of downstream metabolism were also included in the model to allow for eventual use of available urinary and blood biomarker data in animals and humans to calibrate the model for estimation of BD exposures and internal metabolite levels. Results from simulated inhalation exposures to BD indicate that incorporation of differential lung region metabolism is important in describing species differences in pulmonary response and that these differences may have implications for risk assessments of human exposures to BD. PMID:26079054

  17. Preparation of n-tetradecane-containing microcapsules with different shell materials by phase separation method

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Rui [Department of Chemical Engineering, Tsinghua University, Beijing (China); Zhang, Yan; Zhang, Qingwu [Department of Chemical Engineering, China University of Mining and Technology, Beijing (China); Wang, Xin; Zhang, Yinping [Department of Building Science, Tsinghua University, Beijing (China)

    2009-10-15

    Microcapsules for thermal energy storage and heat-transfer enhancement have attracted great attention. Microencapsulation of n-tetradecane with different shell materials was carried out by phase separation method in this paper. Acrylonitrile-styrene copolymer (AS), acrylonitrile-styrene-butadiene copolymer (ABS) and polycarbonate (PC) were used as the shell materials. The structures, morphologies and the thermal capacities of the microcapsules were characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The ternary phase diagrams showed the potential encapsulation capabilities of the three shell materials. The effects of the shell/core ratio and the molecular weight of the shell material on the encapsulation efficiency and the thermal capacity of the microcapsules were also discussed. Microcapsules with melting enthalpy > 100 J/g, encapsulation efficiency 66-75%, particle size<1 {mu}m were obtained for all three shell materials. (author)

  18. Characterization of a Poly(styrene-block-methylacrylate-random-octadecylacrylate-block-styrene) Shape Memory ABA Triblock Copolymer

    Science.gov (United States)

    Fei, Pengzhan; Cavicchi, Kevin

    2011-03-01

    A new ABA triblock copolymer of poly(styrene-block- methylacrylate-random-octadecylacrylate-block-styrene) (PS-b- PMA-r-PODA-b-PS) was synthesized by reversible addition fragmentation chain transfer polymerization. The triblock copolymer can generate a three-dimensional, physically crosslinked network by self-assembly, where the glassy PS domains physically crosslink the midblock chains. The side chain crystallization of the polyoctadecylacrylare (PODA) side chain generates a second reversible network enabling shape memory properties. Shape memory tests by uniaxial deformation and recovery of molded dog-bone shape samples demonstrate that shape fixities above 96% and shape recoveries above 98% were obtained for extensional strains up to 300%. An outstanding advantage of this shape memory material is that it can be very easily shaped and remolded by elevating the temperature to 140circ; C, and after remolding the initial shape memory properties are totally recovered by eliminating the defects introduced by the previous deformation cycling.

  19. Poly(styrene-b-dimethylsiloxane-b-styrene) Membranes in Pervaporation for In Situ Product Recovery during Fermentation

    Science.gov (United States)

    Shin, Chaeyoung; Baer, Zachary; Ozcam, Ali Evren; Clark, Douglas; Balsara, Nitash

    2014-03-01

    In situ product recovery was investigated in fermentation experiments to enable the development of a continuous fermentation process. Our pervaporation membranes are based on poly(styrene-b-dimethylsiloxane-b-styrene) (SDS) block copolymers. Polydimethylsiloxane (PDMS) is the best known organophilic pervaporation membrane material and was utilized as the transporting phase for selective permeation of organic molecules. The polystyrene (PS) block added structural integrity to the membrane due to the high modulus of PS. SDS membranes were found to have both the enhanced robustness as well as comparable pervaporation performance to that of cross-linked PDMS membranes. The permeabilities of water and organic components through SDS membranes were studied to elucidate the sorption and transport phenomena in this system. Furthermore, experiments combining fermentation with pervaporation were performed, and continuous fermentation by using pervaporation as the sole means of removing products was successfully demonstrated for the first time.

  20. Stabilization of polypropylene, polypropylene blends with poly (styrene-b-(ethylene-co-butylene)-b-styrene) under irradiation: A comparative investigation

    Energy Technology Data Exchange (ETDEWEB)

    Luan Shifang; Yang Huawei; Shi Hengchong; Zhao Jie [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Wang Jianwei [Shandong Weigao Group Medical Polymer Company Limited, Weihai 264209 (China); Yin Jinghua, E-mail: yinjh@ciac.jl.c [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

    2011-01-15

    The aim of this paper is to investigate the stabilization of polypropylene in the poly (styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS)/polypropylene (PP) blends under irradiation with respect to PP. The PP films, SEBS/PP films were subjected to electron beam irradiation and characterized by wide angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), gel permeation chromatography (GPC), and dynamic mechanical thermal analysis (DMTA). It demonstrated that upon irradiation, the molecular weight of PP had a pronounced decrease due to the major chain scission, and the minor chain cross-linking or chain branching occurred at the higher irradiation dose. Stabilization of PP was improved in the presence of SEBS, exhibiting an enhanced irradiation resistance.

  1. Sulfonate-containing Copolymers Prepared by Semi-Continuous Emulsion Copolymerizaiton of Styrene and Sodium Styrene Sulfonate

    Institute of Scientific and Technical Information of China (English)

    Shiming HUANG; Wei XIE; Chengyou KAN; Yajie LI; Deshan LIU

    2005-01-01

    @@ 1Introduction Soap-free emulsion copolymerization of styrene (St) and sodium sulfonate styrene (NaSS) could yield homodisperse sulfonate-containing particles with clean surface. But the incorporation of NaSS could never be increased beyond 2.6 % by weight in the conventional batch and seeded emulsion copolymerization in the absence of emulsifier because large amounts of soluble polyelectrolyte would unstablize the reaction system if excessive amount of NaSS was used[1]. In our work, semi-continuous copolymerizations were carried out in the presence of mixed emulsifiers, and a new method to purify the latex polymer was developed. The influences of the NaSS mole ratio in the total monomers and the monomer addition time on the S content in the purified copolymer were investigated by elemental analysis.

  2. Effects of Surfactants on the Properties of Mortar Containing Styrene/Methacrylate Superplasticizer

    OpenAIRE

    El-Sayed Negim; Latipa Kozhamzharova; Jamal Khatib; Lyazzat Bekbayeva; Craig Williams

    2014-01-01

    The physical and mechanical properties of mortar containing synthetic cosurfactants as air entraining agent are investigated. The cosurfactants consist of a combination of 2% dodecyl benzene sodium sulfonate (DBSS) and either 1.5% polyvinyl alcohol (PVA) or 1.5% polyoxyethylene glycol monomethyl ether (POE). Also these cosurfactants were used to prepare copolymers latex: styrene/butyl methacrylate (St/BuMA), styrene/methyl methacrylate (St/MMA), and styrene/glycidyl methacrylate (St/GMA), in...

  3. Side chain alkylation of toluene with methanol over basic zeolites - novel production route towards styrene?

    OpenAIRE

    Rep, Marco

    2002-01-01

    Styrene is an important monomer for the production of different types of (co-) polymers that are used in, e.g., toys, medical devices, food packaging, paper coatings etc. Styrene is produced with several different industrial processes. In 1998, the production of styrene monomer was approximately 21 million tons that are produced or used by more than 15,000 plants worldwide. Two of the largest production processes are described in Chapter 1 and both have their major drawbacks. These drawbacks ...

  4. In vivo and in vitro characterization of poly(styrene-b-isobutylene-b-styrene) copolymer stent coatings for biostability, vascular compatibility and mechanical integrity.

    Science.gov (United States)

    Strickler, Fred; Richard, Robert; McFadden, Sharon; Lindquist, Jeff; Schwarz, Marlene C; Faust, Rudolf; Wilson, Gregory J; Boden, Mark

    2010-02-01

    The TAXUS Express 2 Paclitaxel Eluting Coronary Stent System employs a coating consisting of the thermoplastic elastomer, poly(styrene-b-isobutylene-b-styrene; SIBS), selected for its drug-eluting characteristics, vascular compatibility, mechanical properties, and biostability. This study was conducted to evaluate the impact of different SIBS (17-51 mole % styrene) compositions on mechanical properties, chemical stability, and vascular compatibility. Mechanical property (stress-strain measurements) and stability studies were conducted on polymer films with five different styrene contents (17, 24, 32, 39, and 51 mole %). The ultimate tensile strength did not change significantly with composition, but the elongation at break decreased with increased styrene content. A pulsatile fatigue test further confirmed the mechanical stability of SIBS up to 39 mole % styrene. The vascular compatibility of five different SIBS compositions was assessed using SIBS-only coated stents, in the coronary and carotid arteries in a porcine model study. The stability of the vessel wall, rate/degree of endothelialization, inflammation, and thrombus at timepoints from 30 to 180 days were evaluated. The results confirm vascular compatibility over the range of 17-51 mole % styrene.

  5. Conversion of ethanol to 1,3-butadiene over Na doped ZnxZryOz mixed metal oxides

    Energy Technology Data Exchange (ETDEWEB)

    Baylon, Rebecca A.; Sun, Junming; Wang, Yong

    2016-01-01

    Despite numerous studies on different oxide catalysts for the ethanol to 1,3-butadiene reaction, few have identified active sites (i.e., type of acidity) correlated to the catalytic performances. In this work, the type of acidity needed for ethanol to 1,3-butadiene conversion has been studied over Zn/Zr mixed oxide catalysts. Specifically, synthesis method, Zn/Zr ratio, and Na doping have been used to control the surface acid-base properties, as confirmed by characterizations such as NH3-TPD and IR-Py techniques. The 2000 ppm Na doped Zn1Zr10Oz-H with balanced base and weak Bronsted acid sites was found to give not only high selectivity to 1,3-butadiene (47%) at near complete ethanol conversion (97%), but also exhibited a much higher 1,3-butadiene productivity than other mixed oxides studied.

  6. Synthesis of novel N-, S-substituted-polyhalo-1, 3-butadienes and crystal structure of dibutadienyl homopiperazine

    Indian Academy of Sciences (India)

    Nahide Gulsah Deniz; Cemil Ibis

    2013-07-01

    Polyhalogenated-2-nitro-1, 3-butadienes are important synthetic precursors for a variety of polyfunctionalized bioactive heterocycles. Herein, we report the reactions of 1, 1, 3, 4, 4-pentachloro-2-nitro-1, 3-butadiene 1 and 4-bromo-1, 1, 3, 4-tetrachloro-2-nitro-1, 3-butadiene 2 with amino and thiol containing nucleophiles to obtain highly functionalized (E)-polyhalodiene-2-nitro-1, 3-butadiene derivatives. Most of these reactions were found to be highly selective resulting in good to high yields of the products. All new compounds have been characterized by nuclear magnetic resonance spectroscopy (NMR), mass spectrometry (MS) and Fourier transform infrared spectroscopy (FT-IR) spectroscopic data. Single crystal X-ray structure analysis of compound 8c is reported.

  7. Improved procedure for determination of acrylonitrile in foods and its application to meat.

    Science.gov (United States)

    Page, B D; Charbonneau, C F

    1985-01-01

    The previously described headspace-gas chromatographic procedure for the determination of acrylonitrile (AN) in several foods, with N/P selective detection, has been modified to include packaged luncheon meats. The loss of AN during equilibration at 100 degrees C in meat samples as well as the previously described loss in cold pack cheese and peanut butter has been studied. The loss of AN could be prevented by the addition of 10% phosphoric acid, which increases the acidity of the food-acid-salt slurry to pH 1.2-1.5. This acidification permits detection of AN at 2 ppb (5% FSD at 16 X 10(-2) amp/mV) in all foods studied. AN was not detected in 10 samples of luncheon meat packaged in AN-based plastic which contained up to 2.6 ppm AN.

  8. Studies of plastic crystal gel polymer electrolytes based on poly(vinylidene chloride-co-acrylonitrile)

    Science.gov (United States)

    Hambali, D.; Zainuddin, Z.; Supa'at, I.; Osman, Z.

    2016-02-01

    In this work, we have prepared systems of poly(vinylidene chloride-co-acrylonitrile) (PVdC-co-AN) based gel polymer electrolytes (GPEs) which are single plasticized-GPEs and double plasticized-GPEs. Both systems comprised plastic crystal succinonitrile SN to form plastic crystal gel polymer electrolyte (PGPE) films. The ionic conductivity of the PGPE films were analysed by means of a.c. impedance spectroscopy at room temperature as well as at the temperature range of 303 K to 353 K. The temperature dependence ionic conductivity was found to obey the VTF rule. To study the interactions among the constituents in the PGPEs, Fourier Transform Infrared Spectroscopy (FTIR) was carried out and hence, the complexation between them has also been confirmed.

  9. Efficient polymerization of acrylonitrile catalyzed by diValent lanthanide complex/sodium phenolate systems

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Four divalent lanthanide complexes Sm(ArO)2(THF)4, Yb(ArO)2(THF)3, Eu(ArO)2(THF)3 (ArO = 2,6-ditert-butyl-4-methylphenolate) and (ButCp)2Sm(THF)2 were synthesized. Their catalytic activities on the polymerization of acrylonitrile were studied. The catalytic activities were influenced by the central metal ions involved. The catalytic activities of these divalent lanthanide complexes can be greatly increased by adding NaOC~H2-2,6-But2-4-Me,NaOC6H4-4-But, or NaOC10H6-2-Me. The amount of additive has apparent effect on the catalytic activity, but the additive has no effect on the tacticity of the resulting polyacrylonitrile

  10. A flexible Li polymer primary cell with a novel gel electrolyte based on poly(acrylonitrile)

    Science.gov (United States)

    Akashi, Hiroyuki; Tanaka, Ko-ichi; Sekai, Koji

    The performance of a Li polymer primary cell with fire-retardant poly(acrylonitrile) (PAN)-based gel electrolytes is reported. By optimizing electrodes, electrolytes, the packaging material, and the structural design of the polymer cell, we succeeded in developing a "film-like" Li polymer primary cell with sufficient performance for practical use. The cell is flexible and less than 0.5 mm thick, which makes it suitable for a power source for some smart devices, such as an IC card. Fast cation conduction in the gel electrolyte minimizes the drop of the discharge capacity even at -20 °C. The high chemical stability of the gel electrolytes and the new packaging material allow the self-discharge rate to be limited to under 4.3%, which is equivalent to that of conventional coin-shaped or cylindrical Li-MnO 2 cells.

  11. Acrylonitrile-14C metabolism in rats: effect of the route of administration on the elimination of thiocyanate and other radioactive metabolites in urine and feces

    International Nuclear Information System (INIS)

    In Wistar rats, the elimination of the sum of radioactive metabolites of acrylonitrile-14C was not markedly influenced by the route of acrylonitrile administration. The elimination of thiocyanate, however, was significantly higher after oral (23% of the dose) than after intraperitoneal (4%), subcutaneous (4.6%), or intravenous (1.2%) administrations. The elimination of the sum of radioactive metabolites was highest in the first 4 hours after acrylonitrile administration and rapidly decreased whereas the excretion of thiocyanate reached the maximum between hours 8 and 14 after oral or intraperitoneal administration. Less than 1% of the radioactivity of the acrylonitrile-14C dose was eliminated in feces irrespective of the route of administration. (author)

  12. Covalent immobilization of glucose oxidase onto new modified acrylonitrile copolymer/silica gel hybrid supports.

    Science.gov (United States)

    Godjevargova, Tzonka; Nenkova, Ruska; Dimova, Nedyalka

    2005-08-12

    New polymer/silica gel hybrid supports were prepared by coating high surface area of silica gel with modified acrylonitrile copolymer. The concentrations of the modifying agent (NaOH) and the modified polymer were varied. GOD was covalently immobilized on these hybrid supports and the relative activity and the amount of bound protein were determined. The highest relative activity and sufficient amount of bound protein of the immobilized GOD were achieved in 10% NaOH and 2% solution of modified acrylonitrile copolymer. The influence of glutaraldehyde concentration and the storage time on enzyme efficiency were examined. Glutaraldehyde concentration of 0.5% is optimal for the immobilized GOD. It was shown that the covalently bound enzyme (using 0.5% glutaraldehyde) had higher relative activity than the activity of the adsorbed enzyme. Covalently immobilized GOD with 0.5% glutaraldehyde was more stable for four months in comparison with the one immobilized on pure silica gel, hybrid support with 10% glutaraldehyde and the free enzyme. The effect of the pore size on the enzyme efficiency was studied on four types of silica gel with different pore size. Silica with large pores (CPC-Silica carrier, 375 A) presented higher relative activity than those with smaller pore size (Silica gel with 4, 40 and 100 A). The amount of bound protein was also reduced with decreasing the pore size. The effect of particle size was studied and it was found out that the smaller the particle size was, the greater the activity and the amount of immobilized enzyme were. The obtained results proved that these new polymer/silica gel hybrid supports were suitable for GOD immobilization. PMID:16080168

  13. Photoinitiated decomposition of substituted ethylenes: The photodissociation of vinyl chloride and acrylonitrile at 193 nm

    Energy Technology Data Exchange (ETDEWEB)

    Blank, D.A.; Suits, A.G.; Lee, Y.T. [Lawrence Berkeley National Lab., CA (United States)] [and others

    1997-04-01

    Ethylene and its substituted analogues (H{sub 2}CCHX) are important molecules in hydrogen combustion. As the simplest {pi}-bonded hydrocarbons these molecules serve as prototypical systems for understanding the decomposition of this important class of compounds. The authors have used the technique of photofragment translational spectroscopy at beamline 9.0.2.1 to investigate the dissociation of vinyl chloride (X=Cl) and acrylonitrile (X=CN) following absorption at 193 nm. The technique uses a molecular beam of the reactant seeded in helium which is crossed at 90 degrees with the output of an excimer laser operating on the ArF transition, 193.3 nm. The neutral photoproducts which recoil out of the molecular beam travel 15.1 cm where they are photoionized by the VUV undulator radiation, mass selected, and counted as a function of time. The molecular beam source is rotatable about the axis of the dissociation laser. The authors have directly observed all four of the following dissociation channels for both systems: (1) H{sub 2}CCHX {r_arrow} H + C{sub 2}H{sub 2}X; (2) H{sub 2}CCHX {r_arrow} X + C{sub 2}H{sub 3}; (3) H{sub 2}CCHX {r_arrow} H{sub 2} + C{sub 2}HX; and (4) H{sub 2}CCHX {r_arrow} HX + C{sub 2}H{sub 2}. They measured translational energy distributions for all of the observed channels and measured the photoionization onset for many of the photoproducts which provided information about their chemical identity and internal energy content. In the case of acrylonitrile, selective product photoionization provided the ability to discriminate between channels 2 and 4 which result in the same product mass combination.

  14. The Effect of Uncertainty in Exposure Estimation on the Exposure-Response Relation between 1,3-Butadiene and Leukemia

    Directory of Open Access Journals (Sweden)

    George Maldonado

    2009-09-01

    Full Text Available Abstract: In a follow-up study of mortality among North American synthetic rubber industry workers, cumulative exposure to 1,3-butadiene was positively associated with leukemia. Problems with historical exposure estimation, however, may have distorted the association. To evaluate the impact of potential inaccuracies in exposure estimation, we conducted uncertainty analyses of the relation between cumulative exposure to butadiene and leukemia. We created the 1,000 sets of butadiene estimates using job-exposure matrices consisting of exposure values that corresponded to randomly selected percentiles of the approximate probability distribution of plant-, work area/job group-, and year specific butadiene ppm. We then analyzed the relation between cumulative exposure to butadiene and leukemia for each of the 1,000 sets of butadiene estimates. In the uncertainty analysis, the point estimate of the RR for the first non zero exposure category (>0–<37.5 ppm-years was most likely to be about 1.5. The rate ratio for the second exposure category (37.5–<184.7 ppm-years was most likely to range from 1.5 to 1.8. The RR for category 3 of exposure (184.7–<425.0 ppm-years was most likely between 2.1 and 3.0. The RR for the highest exposure category (425.0+ ppm-years was likely to be between 2.9 and 3.7. This range off RR point estimates can best be interpreted as a probability distribution that describes our uncertainty in RR point estimates due to uncertainty in exposure estimation. After considering the complete probability distributions of butadiene exposure estimates, the exposure-response association of butadiene and leukemia was maintained. This exercise was a unique example of how uncertainty analyses can be used to investigate and support an observed measure of effect when occupational exposure estimates are employed in the absence of direct exposure measurements.

  15. Towards a Biocatalyst for (S)-Styrene Oxide Production: Characterization of the Styrene Degradation Pathway of Pseudomonas sp. Strain VLB120

    OpenAIRE

    Panke, Sven; Witholt, Bernard; Schmid, Andreas; Wubbolts, Marcel G.

    1998-01-01

    In order to design a biocatalyst for the production of optically pure styrene oxide, an important building block in organic synthesis, the metabolic pathway and molecular biology of styrene degradation in Pseudomonas sp. strain VLB120 was investigated. A 5.7-kb XhoI fragment, which contained on the same strand of DNA six genes involved in styrene degradation, was isolated from a gene library of this organism in Escherichia coli by screening for indigo formation. T7 RNA polymerase expression e...

  16. Synthesis and Thermal Properties of Acrylonitrile/Butyl Acrylate/Fumaronitrile and Acrylonitrile/Ethyl Hexyl Acrylate/Fumaronitrile Terpolymers as a Potential Precursor for Carbon Fiber

    Directory of Open Access Journals (Sweden)

    Siti Nurul Ain Md Jamil

    2014-09-01

    Full Text Available A synthesis of acrylonitrile (AN/butyl acrylate (BA/fumaronitrile (FN and AN/EHA (ethyl hexyl acrylate/FN terpolymers was carried out by redox polymerization using sodium bisulfite (SBS and potassium persulphate (KPS as initiator at 40 °C. The effect of comonomers, BA and EHA and termonomer, FN on the glass transition temperature (Tg and stabilization temperature was studied using Differential Scanning Calorimetry (DSC. The degradation behavior and char yield were obtained by Thermogravimetric Analysis. The conversions of AN, comonomers (BA and EHA and FN were 55%–71%, 85%–91% and 76%–79%, respectively. It was found that with the same comonomer feed (10%, the Tg of AN/EHA copolymer was lower at 63 °C compared to AN/BA copolymer (70 °C. AN/EHA/FN terpolymer also exhibited a lower Tg at 63 °C when compared to that of the AN/BA/FN terpolymer (67 °C. By incorporating BA and EHA into a PAN system, the char yield was reduced to ~38.0% compared to that of AN (~47.7%. It was found that FN reduced the initial cyclization temperature of AN/BA/FN and AN/EHA/FN terpolymers to 228 and 221 °C, respectively, in comparison to that of AN/BA and AN/EHA copolymers (~260 °C. In addition, FN reduced the heat liberation per unit time during the stabilization process that consequently reduced the emission of volatile group during this process. As a result, the char yields of AN/BA/FN and AN/EHA/FN terpolymers are higher at ~45.1% and ~43.9%, respectively, as compared to those of AN/BA copolymer (37.1% and AN/EHA copolymer (38.0%.

  17. 提高丙烯腈回收率的一种新型急冷工艺和急冷塔%A new quenching process and tower to improve the recovery of acrylonitrile

    Institute of Scientific and Technical Information of China (English)

    甘永胜; 顾军民; 方永成

    2004-01-01

    Quenching process and design of the quenching tower in acrylonitrile production in China were studied in order to decrease the polymerization loss of acrylonitrile in the quenching tower.Based on the research of acrylonitrile polymerization in the quenching tower,a new quenching process was proposed to avoid the disadvantages of the original process.Two kinds of internals were installed to improve the performance of the quenching tower.Through a series of air-flow and real-flow model experiments,the new quenching process and new design were showed to be successful in enhancing the mass and heat transfer in the vapor-liquid system and decreasing the loss of acrylonitrile.Industrial application showed satisfactory results of decrease of the acrylonitrile loss in the quenching tower by about 4.5% and increase of the acrylonitrile recovery of the whole plant by more than 4%.

  18. Genotoxicity of 1,3-butadiene and its epoxy intermediates.

    Science.gov (United States)

    Walker, Vernon E; Walker, Dale M; Meng, Quanxin; McDonald, Jacob D; Scott, Bobby R; Seilkop, Steven K; Claffey, David J; Upton, Patricia B; Powley, Mark W; Swenberg, James A; Henderson, Rogene F

    2009-08-01

    Current risk assessments of 1,3-butadiene (BD*) are complicated by limited evidence of its carcinogenicity in humans. Hence, there is a critical need to identify early events and factors that account for the heightened sensitivity of mice to BD-induced carcinogenesis and to deter-mine which animal model, mouse or rat, is the more useful surrogate of potency for predicting health effects in BD-exposed humans. HEI sponsored an earlier investigation of mutagenic responses in mice and rats exposed to BD, or to the racemic mixture of 1,2-epoxy-3-butene (BDO) or of 1,2,3,4-diepoxybutane (BDO2; Walker and Meng 2000). In that study, our research team demonstrated (1) that the frequency of mutations in the hypoxanthine-guanine phosphoribosyl transferase (Hprt) gene of splenic T cells from BD-exposed mice and rats could be correlated with the species-related differences in cancer susceptibility; (2) that mutagenic-potency and mutagenic-specificity data from mice and rats exposed to BD or its individual epoxy intermediates could provide useful information about the BD metabolites responsible for mutations in each species; and (3) that our novel approach to measuring the mutagenic potency of a given chemical exposure as the change in Hprt mutant frequencies (Mfs) over time was valuable for estimating species-specific differences in mutagenic responses to BD exposure and for predicting the effect of BD metabolites in each species. To gain additional mode-of-action information that can be used to inform studies of human responses to BD exposure, experiments in the current investigation tested a new set of five hypotheses about species-specific patterns in the mutagenic effects in rodents of exposure to BD and BD metabolites: 1. Repeated BD exposures at low levels that approach the occupational exposure limit for BD workers (set by the U.S. Occupational Safety and Health Administration) are mutagenic in female mice. 2. The differences in mutagenic responses of the Hprt gene to BD

  19. Oxidative Dehydrogenation of Butane to Butadiene and Butene Using a Novel Inert Membrane Reactor

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The oxidative dehydrogenation of butane to butadiene and butene was studied using a conventional fixed-bed ractor (FBR), inert membrane reactor (IMR) and mixed inert membrane reactor (MIMR). When IMR and MIMR were employed, a ceramic membrane modified by partially coating with glaze was used to distribute oxygen to a fixed-bed of 24-V-Mg-O catalyst. The oxygen partial pressure in the catalyst bed could be decreased. The effect of feeding modes and operation conditions were investigated. The selectivity of C4 dehydrogenation products (butene and butadiene) was found to be higher in IMR than in FBR. The feeding mode with 20% of air mixing with butane in MIMR was found to be more efficient than the feeding mode with all air permeating through ceramic membrane. The MIMR gave the most smooth temperature profile along the bed.

  20. Poly(styrene-acrylic acid) magnetic polymer microspheres

    Institute of Scientific and Technical Information of China (English)

    Yanling CHENG; Liuqiang MA; Ruohui LI

    2008-01-01

    Magnetic polymer microspheres have been considered as a kind of new biopolymer materials with great advantages in bioseparation engineering and biome-dicine engineering because they have not only polymer functional groups but also magnetic characteristics. Styrene-acrylic acid copolymer (p(S-AA)) magnetic microspheres were synthesized by dispersion polymeriza-tion with Fe3O4 as core and p(S-AA) as shell. The micro-spheres were characterized by SEM, size analysis, molecular weight and solid content measurement. All of them indicate that the microspheres are small in size, nar-row in distribution, stable in chemistry and rich in func-tional groups on their surface.

  1. PHOTOINDUCED CHARGE TRANSFER POLYMERIZATION OF STYRENE INITIATED BY ELECTRON ACCEPTOR

    Institute of Scientific and Technical Information of China (English)

    CAO Weixiao; ZHANG Peng; FENG Xinde

    1995-01-01

    Photoinduced charge transfer polymerization of styrene(St) with electron acceptor as initiator was investigated. In case of fumaronitrile (FN) or maleic anhydride (MA) as initiator the polymerization takes place regularly, whereas the tetrachloro-1, 4-benzenequinone (TCQ), 2, 3-dichloro-5, 6-dicyano-1, 4-benzenequinone (DDQ) . or tetracyano ethylene (TCNE) as initiator the polymerization proceeds reluctantly only after the photoaddition reaction. A mechanism was proposed that free radicals would be formed following the charge and proton transfer in the exciplex formed between St and electron acceptors.

  2. Bioconversion of Styrene to Poly(hydroxyalkanoate) (PHA) by the New Bacterial Strain Pseudomonas putida NBUS12

    OpenAIRE

    Tan, Giin-Yu Amy; Chen, Chia-Lung; Ge, Liya; Ling LI; Tan, Swee Ngin; Wang, Jing-Yuan

    2015-01-01

    Styrene is a toxic pollutant commonly found in waste effluents from plastic processing industries. We herein identified and characterized microorganisms for bioconversion of the organic eco-pollutant styrene into a valuable biopolymer medium-chain-length poly(hydroxyalkanoate) (mcl-PHA). Twelve newly-isolated styrene-degrading Pseudomonads were obtained and partial phaC genes were detected by PCR in these isolates. These isolates assimilated styrene to produce mcl-PHA, forming PHA contents be...

  3. Letter to the Editor: Styrene-producing microbes in food-stuff

    Science.gov (United States)

    An article was published in Journal of Food Science, August 2009 (Vol. 74, Nr 6) entitled “Natural formation of styrene by cinnamon mold flora”. In the article, the authors reported on the production of styrene from several fungi typically found on cinnamon, and used cinnamic acid and similar analog...

  4. 40 CFR 721.3700 - Fatty acid, ester with styrenated phenol, ethylene oxide adduct.

    Science.gov (United States)

    2010-07-01

    ... phenol, ethylene oxide adduct. 721.3700 Section 721.3700 Protection of Environment ENVIRONMENTAL... Significant New Uses for Specific Chemical Substances § 721.3700 Fatty acid, ester with styrenated phenol... chemical substance identified generically as fatty acid, ester with styrenated phenol, ethylene...

  5. Initiation precursors and initiators in laser-induced copolymerization of styrene and maleic anhydride in acetone

    Science.gov (United States)

    Miner, Gilda A.; Meador, Willard E.; Chang, C. Ken

    1990-01-01

    The initiation step of photopolymerized styrene/maleic anhydride copolymer was investigated at 365 nm. UV absorption measurements provide decisive evidence that the styrene/maleic anhydride charge transfer complex is the sole absorbing species; however, key laser experiments suggest intermediate reactions lead to a monoradical initiating species. A mechanism for the photoinitiation step of the copolymer is proposed.

  6. Coke formation in the oxidative dehydrogenation of ethylbenzene to styrene by TEOM

    NARCIS (Netherlands)

    Nederlof, C.; Vijfhuizen, P.; Zarubina, V.; Melian-Cabrera, I.; Kapteijn, F.; Makkee, M.

    2014-01-01

    A packed bed microbalance reactor setup (TEOM-GC) is used to investigate the formation of coke as a function of time-on-stream on gamma-Al2O3 and 3P/SiO2 catalyst samples under different conditions for the ODH reaction of ethylbenzene to styrene. All samples show a linear correlation of the styrene

  7. Coke formation in the oxidative dehydrogenation of ethylbenzene to styrene by TEOM

    NARCIS (Netherlands)

    C. Nederlof; P. Vijfhuizen; V. Zarubina; I. Melián-Cabrera; F. Kapteijn; M. Makkee

    2014-01-01

    A packed bed microbalance reactor setup (TEOM-GC) is used to investigate the formation of coke as a function of time-on-stream on γ-Al2O3 and 3P/SiO2 catalyst samples under different conditions for the ODH reaction of ethylbenzene to styrene. All samples show a linear correlation of the styrene sele

  8. 21 CFR 173.70 - Chloromethylated aminated styrene-divinylbenzene resin.

    Science.gov (United States)

    2010-04-01

    ... resin. 173.70 Section 173.70 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Chloromethylated aminated styrene-divinylbenzene resin. Chloromethylated aminated styrene-divinylbenzene copolymer... resin dispersion. (c) The additive is used as a decolorizing and clarification agent for treatment...

  9. New Piperazine Derivatives Synthesized from Thio-Substituted Polyhalogeno-2-nitro-1,3-butadienes

    OpenAIRE

    S. Goksin Aydinli; Cemil Ibis

    2010-01-01

    It is known that polyhalogeno-nitro-1,3-butadienes are important starting materials for the synthesis of polyfunctionalized bioactive heterocycles. Novel N,S-substituted nitrobutadienes (4a-j) were synthesized from the reaction of the monothio-substituted nitrodiene derivatives (2a) and (2b) with some piperazine derivatives. These new compounds are stable and the structures of these products were characterized by spectroscopic data. The structure of the novel N,S-substituted nitrodiene compou...

  10. REDUCING NONSELECTIVE PROTEIN ADSORPTION AND CELL ADHESION ON POLYACRYLONITRILE FILMS BY COPOLYMERIZATION OF ACRYLONITRILE WITH α-ALLYL GLUCOSIDE

    Institute of Scientific and Technical Information of China (English)

    Rui-qiang Kou; Chao Qu; Zhi-kang Xu; You-yi Xu; Ke Yao

    2003-01-01

    In this work, the surface properties of novel sugar-containing polymers, α-allyl glucoside (AG)/acrylonitrile (AN)copolymers, were studied by contact angle, protein adsorption and cell adhesion measurements. It was found that the contact angle of the copolymer films decreased from 68° to 30° with the increase of AG content in the copolymer. The adsorption amount of bovine serum albumin (BSA) and the adhesive macrophage onto the film surface also decreased significantly with increasing α-allyl glucoside content from 0 to 42 wt% in the copolymer. These preliminary results reveal that both the hydrophilicity and the biocompatibility of polyacrylonitrile-based membranes could be improved by copolymerizing acrylonitrile with vinyl carbohydrates.

  11. Inhalation developmental toxicology studies: Teratology study of 1,3-butadiene in mice: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hackett, P.L.; Sikov, M.R.; Mast, T.J.; Brown, M.G.; Buschbom, R.L.; Clark, M.L.; Decker, J.R.; Evanoff, J.J.; Rommereim, R.L.; Rowe, S.E.; Westerberg, R.B.

    1987-11-01

    Maternal toxicity, reproductive performance and developmental toxicology were evaluated in CD-1 mice following whole-body, inhalation exposures to 0, 40, 200 and 1000 ppM of 1,3-butadiene. The female mice, which had mated with unexposed males were exposed to the chemical for 6 hours/day on 6 through 15 dg and sacrificed on 18 dg. Maternal animals were weighed prior to mating and on 0, 6, 11 and 18 dg; the mice were observed for mortality, morbidity and signs of toxicity during exposure and examined for gross tissue abnormalities at necropsy. Live fetuses were weighed and subjected to external, visceral and skeletal examinations to detect growth retardation and morphologic anomalies. Significant concentration-related decreases were detected in a number of maternal body weight measures. There was a significant concentration-related depression of fetal body weights and placental weights. Body weights of male fetuses of all exposed groups were significantly lower than values for control fetuses; weights of female fetuses were significantly depressed in the mice exposed to 200 and 1000 ppM. In the 200- and 1000-ppM exposure groups, weights of placentas of male fetuses were significantly decreased, but placental weights of female fetuses were significantly affected only in litters exposed to the highest 1,3-butadiene concentration. This exposure regimen produced significant signs of maternal toxicity at concentrations of 200 and 1000 ppM 1,3-butadiene.

  12. In Situ IR Spectroscopic Study on the Hydrogenation of 1,3-Butadiene on Fresh Mo2C/γ-Al2O3 Catalyst

    Institute of Scientific and Technical Information of China (English)

    Zhang Jing; Wu Weicheng; Liu Shiyang

    2014-01-01

    The surface species formed from the adsorption of 1,3-butadiene and 1,3-butadiene hydrogenation over the fresh Mo2C/γ-Al2O3 catalyst was studied by in situ IR spectroscopy. It is found that 1,3-butadiene adsorption on the Mo2C/γ-Al2O3 catalyst mainly formsπ-adsorbed butadiene (πs andπd) andσ-bonded surface species. These species are adsorbed mainly on the surface Moδ+(0<δ<2) sites as evidenced by co-adsorption of 1,3-butadiene and CO on the fresh Mo2C/γ-Al2O3 catalyst. The IR spectrometric analysis show that hydrogenation of 1,3-butadiene over fresh Mo2C/γ-Al2O3 catalyst produces mainly butane coupled with a small portion of butene. The selectivity of butene during the hydrogenation of 1,3-butadiene over fresh Mo2C/γ-Al2O3 catalyst might be explained by the adsorption mode of adsorbed 1,3-butadiene. Additionally, the active sites of the fresh Mo2C/γ-Al2O3 catalyst may be covered by coke during the hydrogenation reaction of 1,3-butadiene. The treatment with hydrogen at 673 K cannot remove the coke deposits from the surface of the Mo2C/γ-Al2O3 catalyst.

  13. Synthesis and Characterization of Styrene- Ethylene-Propylene-Styrene (SEPS Grafted with Maleic Anhydride (MAH for Use as Coupling Agent in Wood Polymer Composite

    Directory of Open Access Journals (Sweden)

    M. Acevedo-Morantes

    2015-10-01

    Full Text Available Styrene-Ethylene-Propylene-Styrene (SEPS block copolymer was grafted with maleic anhydride (MAH by reactive extrusion (SEPS-g-MAH using an organic peroxide as initiator in the grafting. SEPS-g-MAH was synthesized for use as coupling agent in wood polymer composite (WPC. Identification of this compatibilizer was made using Fourier transform infrared spectroscopy (FTIR and the grafting degree was determinate with titration. The characteristic peaks in FTIR analysis indicated the presence of MAH in the copolymer.

  14. Organocatalytic chemo- and regioselective oxyarylation of styrenes via a cascade reaction: remote activation of hydroxyl groups.

    Science.gov (United States)

    Zhang, Yu-Chen; Jiang, Fei; Wang, Shu-Liang; Shi, Feng; Tu, Shu-Jiang

    2014-07-01

    The first organocatalytic oxyarylation of styrenes has been established through a cascade of vinylogous Michael addition/alkoxyl transfer reactions of o- or p-hydroxylstyrenes with quinone imine ketals. The process leads to a highly chemo- and regioselective oxyarylation of styrenes and provides access to m-alkylated anilines in generally high yields and excellent diastereoselectivity (up to 99% yield, >95:5 dr). An investigation of the reaction pathway revealed that the existence and position of the hydroxyl group of styrene played crucial roles in the cascade reaction, suggesting that the two reactants were simultaneously activated by binaphthyl-derived phosphoric acid via hydrogen bonding interactions and long-distance conjugative effects. In addition, the activating group of the hydroxyl functionality in the products can be easily removed or transformed, demonstrating the applicability and utility of this strategy in styrene oxyarylation and in the synthesis of styrene-based compounds.

  15. 40 CFR 721.7020 - Distillates (petroleum), C(3-6), polymers with styrene and mixed terpenes (generic name).

    Science.gov (United States)

    2010-07-01

    ...), polymers with styrene and mixed terpenes (generic name). 721.7020 Section 721.7020 Protection of...), C(3-6), polymers with styrene and mixed terpenes (generic name). (a) Chemical substance and...), polymers with styrene and mixed terpenes (PMN P-89-676) is subject to reporting under this section for...

  16. Improved Method for Preparation of Amidoxime Modified Poly(acrylonitrile-co-acrylic acid: Characterizations and Adsorption Case Study

    Directory of Open Access Journals (Sweden)

    Nur Amirah Mohd Zahri

    2015-07-01

    Full Text Available Redox polymerization of poly(acrylonitrile-co-acrylic acid (poly(AN-co-AA is performed at 40 °C under N2 gas by varying the ratio of acrylonitrile (AN and acrylic acid (AA in the feed. The yield production of poly(acrylonitrile (PAN is 73% and poly(AN-co-AA with a feed ratio of 93:7 is the highest yield (72%. The PAN and poly(AN-co-AA are further chemically modify with hydroxylamine hydrochloride. The FTIR spectroscopy is used to confirm the copolymerization of poly(AN-co-AA and chemical modification of poly(AN-co-AA. Elemental microanalysis shows that the overall trend percentage of carbon, hydrogen, and nitrogen for all feed ratios are slightly decreasing as the feed ratio of AA is increasing except for poly(AN-co-AA 93:7. The SEM images shows that spherical diameter of poly(AN-co-AA is smaller compared to the PAN and amidoxime (AO modified poly(AN-co-AA. The TGA (thermogravimetric analysis analysis reveals that the poly(AN-co-AA degrades at lower temperatures compared to the PAN but higher than AO modified poly(AN-co-AA. The case study adsorption test showed that the AO modified poly(AN-co-AA 93:7 had the highest percentage removal of Cd2+ and Pb2+.

  17. Uptake of one and two molecules of 1,3-butadiene by platinum bis(dithiolene): a theoretical study.

    Science.gov (United States)

    Dang, Li; Ni, Shao Fei; Hall, Michael B; Brothers, Edward N

    2014-09-15

    Platinum bis(dithiolene) complexes have reactivity toward alkenes like nickel bis(dithiolene) complexes. We examined the uptake of 1,3-butadiene by platinum bis(dithiolene) [Pt(tfd)2] (tfd = S2C2(CF3)2) via a density functional theory study; both 1,2- and 1,4-additions of 1,3-butadiene to the ligands of Pt(tfd)2 to form both interligand and intraligand adducts were studied. For single 1,3-butadiene addition, direct 1,4-addition on interligand S-S, 1,2-addition on intraligand S-S, and 1,4-addition on intraligand S-C are all feasible at room temperature and are controlled by the symmetry of the highest occupied molecular orbital of 1,3-butadiene and the lowest unoccupied molecular orbital of Pt(tfd)2. However, the formation of the interligand S-S adduct through 1,4-addition of one molecule of cis-1,3-butadiene is the most favorable route, with a reaction barrier of 9.3 kcal/mol. The other two addition processes cannot compete with this one due to both higher reaction barriers and unstable adducts. Other possible pathways, such as formation of cis-interligand S-S adduct from 1,2-addition of one molecule of 1,3-butadiene via a twisted trans-interligand S-S adduct, have higher barriers. Our calculated results show that 1,4-addition of a single molecule of 1,3-butadiene on the interligand S-S gives the kinetically stable product by a one-step pathway. But of at least equal importance is the apofacial 1,4-addition of two molecules of 1,3-butadiene on the intraligand S-C of the same ligand on Pt(tfd)2, which yields the thermodynamically stable product, obtained via a short lifetime intermediate, the 1:1 intraligand S-C adduct, being formed through several pathways. The calculated results in this study well explain the experimental observation that 1:1 interligand S-S adduct was formed in a short time, and the intraligand S-C adduct from two molecules of cis-1,3-butadiene was accumulated in 20 h at 50° and characterized by X-ray crystallography. PMID:25184506

  18. Leaching of styrene and other aromatic compounds in drinking water from PS bottles

    Institute of Scientific and Technical Information of China (English)

    Maqbool Ahmad; Ahmad S.Bajahlan

    2007-01-01

    Bottled water may not be safer, or healthier, than tap water. The present studies have proved that styrene and some other aromatic compounds leach continuously from polystyrene (PS) bottles used locally for packaging. Water sapmles in contact with PS were extracted by a preconcentration technique called as "purge and trap" and analysed by gas chromatograph-mass spectrometer (GC/MS). Eleven aromatic compounds were identified in these studies. Maximum concentration of styrene in PS bottles was 29.5 μg/L. Apart from styrene, ethyl benzene, toluene and benzene were also quantified but their concentrations were much less than WHO guide line values. All other compounds were in traces. Quality of plastic and storage time were the major factor in leaching of styrene. Concentration of styrene was increased to 69.53 μg/L after one-year storage time. In Styrofoam and PS cups studies, hot water was found to be contaminated with styrene and other aromatic compounds. It was observed that temperature played a major role in the leaching of styrene monomer from Styrofoam cups. Paper cups were found to be safe for hot drinks.

  19. Influence of Layer Thickness and Raster Angle on the Mechanical Properties of 3D-Printed PEEK and a Comparative Mechanical Study between PEEK and ABS

    Directory of Open Access Journals (Sweden)

    Wenzheng Wu

    2015-09-01

    Full Text Available Fused deposition modeling (FDM is a rapidly growing 3D printing technology. However, printing materials are restricted to acrylonitrile butadiene styrene (ABS or poly (lactic acid (PLA in most Fused deposition modeling (FDM equipment. Here, we report on a new high-performance printing material, polyether-ether-ketone (PEEK, which could surmount these shortcomings. This paper is devoted to studying the influence of layer thickness and raster angle on the mechanical properties of 3D-printed PEEK. Samples with three different layer thicknesses (200, 300 and 400 μm and raster angles (0°, 30° and 45° were built using a polyether-ether-ketone (PEEK 3D printing system and their tensile, compressive and bending strengths were tested. The optimal mechanical properties of polyether-ether-ketone (PEEK samples were found at a layer thickness of 300 μm and a raster angle of 0°. To evaluate the printing performance of polyether-ether-ketone (PEEK samples, a comparison was made between the mechanical properties of 3D-printed polyether-ether-ketone (PEEK and acrylonitrile butadiene styrene (ABS parts. The results suggest that the average tensile strengths of polyether-ether-ketone (PEEK parts were 108% higher than those for acrylonitrile butadiene styrene (ABS, and compressive strengths were 114% and bending strengths were 115%. However, the modulus of elasticity for both materials was similar. These results indicate that the mechanical properties of 3D-printed polyether-ether-ketone (PEEK are superior to 3D-printed ABS.

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

    International Nuclear Information System (INIS)

    A trial was made to design and prepare rubber article that can be used to reactivate, strengthen and reinforce the hand muscles and fingers which had suffered from trouble movement.The investigated rubber article was prepared from natural and acrylonitrile rubber formulations. These formulations were processed in the form of compounds which contain significant quantities of fillers as Hisil, CaCO3 and TiO2.The rheological characteristics and physicochemical properties of the vulcanizations were determined according to standard tests. It was found that it is possible to prepare the designated rubber article for the desired purpose. The test results show that the prepared rubber article has a good chemical resistant against acid, alkali, and salt. Also it possesses high resistance to deterioration and deformation. The prepared article has an ability to retain its elastic property after the action of compressive forces at 70 degree C for 24 hours.This was conformed with applied commercial hand exercise therapeutic article

  1. Effects of acrylonitrile on lymphocyte lipid rafts and RAS/RAF/MAPK/ERK signaling pathways.

    Science.gov (United States)

    Li, X J; Li, B; Huang, J S; Shi, J M; Wang, P; Fan, W; Zhou, Y L

    2014-09-26

    Acrylonitrile (ACN) is a widely used chemical in the production of plastics, resins, nitriles, acrylic fibers, and synthetic rubber. Previous epidemiological investigations and animal studies have confirmed that ACN affects the lymphocytes and spleen. However, the immune toxicity mechanism is unknown. Lipid rafts are cell membrane structures that are rich in cholesterol and involved in cell signal transduction. The B cell lymophoma-10 (Bcl10) protein is a joint protein that is important in lymphocyte development and signal pathways. This study was conducted to examine the in vitro effects of ACN. We separated lipid rafts, and analyzed Bcl10 protein and caveolin. Western blotting was used to detect mitogen-activated protein kinase (MAPK) and phosphorylated MAPK levels. The results indicated that with increasing ACN concentration, the total amount of Bcl10 remained stable, but was concentrated mainly in part 4 to part 11 in electrophoretic band district which is high density in gradient centrifugation. Caveolin-1 was evaluated as a lipid raft marker protein; caveolin-1 content and position were relatively unchanged. Western blotting showed that in a certain range, MAPK protein was secreted at a higher level. At some ACN exposure levels, MAPK protein secretion was significantly decreased compared to the control group (P lipid raft structures, causing Bcl10 protein and lipid raft separation and restraining Ras-Raf-MAPK-extracellular signal-regulated kinase signaling pathways.

  2. Peroxydisulfate initiated synthesis of potato starch-graft-poly(acrylonitrile under microwave irradiation

    Directory of Open Access Journals (Sweden)

    2007-01-01

    Full Text Available Potato starch-graft-poly(acrylonitrile could be efficiently synthesized using small concentration of ammonium peroxydisulfate (0.0014M in aqueous medium under microwave irradiation. A representative microwave synthesized graft copolymer was characterized using Fourier Transform Infrared Spectroscopy, X-ray Diffraction, Scanning Electron Microscopy and Thermogravimetric Analysis. Under microwave conditions oxygen removal from the reaction vessel was not required and the graft copolymer was obtained in high yield using very small amount of ammonium peroxydisulfate, however using the same amount of ammonium peroxydisulfate (0.0014M on thermostatic water bath no grafting was observed up to 98°C (even in inert atmosphere. Raising the concentration of the initiator to 0.24 M resulted into 10% grafting at 50 °C but in inert atmosphere.The viscosity/shear stability of the grafted starch (aqueous solution and water/saline retention ability of the microwave synthesized graft copolymer were also studied and compared with that of the native potato starch.

  3. Nanostructured synthetic carbons obtained by pyrolysis of spherical acrylonitrile/divinylbenzene copolymers.

    Directory of Open Access Journals (Sweden)

    Danish J Malik

    Full Text Available Novel carbon materials have been prepared by the carbonization of acrylonitrile (AN/divinylbenzene (DVB suspension porous copolymers having nominal crosslinking degrees in the range of 30-70% and obtained in the presence of various amounts of porogens. The carbons were obtained by pre-oxidation of AN/DVB copolymers at 250-350°C in air followed by pyrolysis at 850°C in an N(2 atmosphere. Both processes were carried out in one furnace and the resulting material needed no further activation. Resulting materials were characterized by XPS and low temperature nitrogen adsorption/desorption. It was found that maximum pyrolysis yield was ca. 50% depending on the oxidation conditions but almost independent of the crosslinking degree of the polymers. Porous structure of the carbons was characterized for the presence of micropores and macropores, when obtained from highly crosslinked polymers or polymers oxidized at 350°C and meso- and macropores in all other cases. The latter pores are prevailing in the structure of carbons obtained from less porous AN/DVB resins. Specific surface area (BET of polymer derived carbons can vary between 440 m(2/g and 250 m(2/g depending on the amount of porogen used in the synthesis of the AN/DVB polymeric precursors.

  4. AGET ATRP of acrylonitrile with ionic liquids as reaction medium without any additional ligand

    Energy Technology Data Exchange (ETDEWEB)

    Chen Hou, E-mail: lduchenhou@hotmail.com [School of Chemistry and Materials Science, Ludong University, Yantai 264025 (China); Liang Ying; Liu Delong; Tan Zhi; Zhang Shaohong; Zheng Meiling; Qu Rongjun [School of Chemistry and Materials Science, Ludong University, Yantai 264025 (China)

    2010-05-10

    Atom transfer radical polymerization using activators generated by electron transfer (AGET ATRP) of acrylonitrile (AN) was carried out for the first time in 1-methylimidazolium acetate ([mim][AT]), 1-methylimidazolium propionate([mim][PT]), and 1-methylimidazolium butyrate ([mim][BT]), respectively. The polymerization was approached by using ascorbic acid (VC) as a reducing agent, ethyl 2-bromoisobutyrate (EBiB) as initiator, only FeBr{sub 3} as catalyst without any additional ligand. Kinetic studies showed that both AGET ATRP of AN in the absence of oxygen and in the presence of air proceeded in a well-controlled manner. Under the same conditions, the polymerization in the presence of air provided rather slower reaction rate and showed better control of molecular weight and its distribution than in the absence of oxygen. The sequence of the apparent polymerization rate constants of AGET ATRP of AN in three ionic liquids was k{sub app}([mim][AT]) > k{sub app}([mim][PT]) > k{sub app}([mim][BT]). The living nature of the polymerization was confirmed by chain end analysis and block copolymerization of methyl methacrylate with polyacrylonitrile as macroinitiator. All the three ionic liquids and FeBr{sub 3} could be recycled and reused and had no effect on the living nature of polymerization.

  5. "CAGE" VANADYL POLYCARBOXYLATE-THIOUREA COMPLEX FOR THE POLYMERIZATION OF ACRYLONITRILE

    Institute of Scientific and Technical Information of China (English)

    WU Jinyuan; YANG Chaoxiong

    1993-01-01

    The polymerization of acrylonitrile (AN) in aqueous nitric acid initiated by " cage" vanadyl polycarboxylate (P=VO)- thiourea (TU) complex was investigated. The overall rate of polymerization is Rp=9.7×105e-10,500/RT[AN][HNO3]1.5[P =VO]0.50[TU]0.76 The relationship between the induction period (τ) and the temperature of polymerization as well as the concentrations of reactants can be expressed as follows: 1/τ=4.6× 1012e-13,500/RT[HNO3]3[p=VO][TU]3/2=KτRiThe molecular weight of polyacrylonitrile(-Mn)increases with increasing monomer concentrationand decreases with increasing temperature of polymerization and concentrations of vanadyl polycarboxylate and thiourea (-M)n=KM1/τ.[AN]/[HNO3]3/2[P=VO1/2[TU]3/4=KM·1/τ·Rp/R1] The polymerization mechanism was proposed and discussed.

  6. Covalent Immobilization of Lipase on Poly ( acrylonitrile-co-maleic acid) Ultrafiltration Hollow Fiber Membrane

    Institute of Scientific and Technical Information of China (English)

    YE Peng; XU Zhi-kang; WU Jian; DENG Hong-tao; SETA Patrick

    2005-01-01

    Lipase from Candida rugosa was covalently immobilized on the surface of an ultrafiltration hollow fiber membrane fabricated from poly (acrylonitrile-co-maleic acid) (PANCMA) in which the carboxyl groups were activated with 1-ethyl-3-(dimethylaminopropyl) carbodiimide hydrochloride (EDC) and dicyclohexyl carbodiimide (DCC)/N-hydroxyl succinimide(NHS), respectively. The properties of the immobilized lipase were assayed and compared with those of the free enzyme. The maximum activities were observed in a relatively broader pH value range at high temperatures for the immobilized lipase compared to the free one. It was also found that the thermal and pH stabilities of lipase were improved upon immobilization and at 50 ℃ the thermal inactivation rate constant values are 2.1×10-2 for the free lipase, 3.2×10-3 for the immobilized lipase on the EDC-activated PANCMA membrane and 3.5×10-3 for the immobilized lipase on the DCC/NHS-activated PANCMA membrane, respectively.

  7. Cooperativity in CYP2E1 metabolism of acetaminophen and styrene mixtures.

    Science.gov (United States)

    Hartman, Jessica H; Letzig, Lynda G; Roberts, Dean W; James, Laura P; Fifer, E Kim; Miller, Grover P

    2015-10-01

    Risk assessment for exposure to mixtures of drugs and pollutants relies heavily on in vitro characterization of their bioactivation and/or metabolism individually and extrapolation to mixtures assuming no interaction. Herein, we demonstrated that in vitro CYP2E1 metabolic activation of acetaminophen and styrene mixtures could not be explained through the Michaelis-Menten mechanism or any models relying on that premise. As a baseline for mixture studies with styrene, steady-state analysis of acetaminophen oxidation revealed a biphasic kinetic profile that was best described by negative cooperativity (Hill coefficient=0.72). The best-fit mechanism for this relationship involved two binding sites with differing affinities (Ks=830μM and Kss=32mM). Introduction of styrene inhibited that reaction less than predicted by simple competition and thus provided evidence for a cooperative mechanism within the mixture. Likewise, acetaminophen acted through a mixed-type inhibition mechanism to impact styrene epoxidation. In this case, acetaminophen competed with styrene for CYP2E1 (Ki=830μM and Ksi=180μM for catalytic and effector sites, respectively) and resulted in cooperative impacts on binding and catalysis. Based on modeling of in vivo clearance, cooperative interactions between acetaminophen and styrene resulted in profoundly increased styrene activation at low styrene exposure levels and therapeutic acetaminophen levels. Current Michaelis-Menten based toxicological models for mixtures such as styrene and acetaminophen would fail to detect this concentration-dependent relationship. Hence, future studies must assess the role of alternate CYP2E1 mechanisms in bioactivation of compounds to improve the accuracy of interpretations and predictions of toxicity.

  8. Interfacing microbial styrene production with a biocompatible cyclopropanation reaction.

    Science.gov (United States)

    Wallace, Stephen; Balskus, Emily P

    2015-06-01

    The introduction of new reactivity into living organisms is a major challenge in synthetic biology. Despite an increasing interest in both the development of small-molecule catalysts that are compatible with aqueous media and the engineering of enzymes to perform new chemistry in vitro, the integration of non-native reactivity into metabolic pathways for small-molecule production has been underexplored. Herein we report a biocompatible iron(III) phthalocyanine catalyst capable of efficient olefin cyclopropanation in the presence of a living microorganism. By interfacing this catalyst with E. coli engineered to produce styrene, we synthesized non-natural phenyl cyclopropanes directly from D-glucose in single-vessel fermentations. This process is the first example of the combination of nonbiological carbene-transfer reactivity with cellular metabolism for small-molecule production. PMID:25925138

  9. Organolanthanide Compounds Containing Methanesulfonate and Pyrazinamide Ligand in Styrene Polymerization

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The synthesis of organolanthanide compounds identified as LnCp*(MS)2PzA, Ln=Sm, Tb, Yb (MS=methanesulfonate, Cp*=pentamethylcyclopentadienyl, and PzA=pyrazinamide), by the reaction of coordination compounds Ln(MS)3(PzA)4 with NaCp in THF was reported. The complexes were formulated according to elemental analyses, complexometric titration with EDTA (%Ln), and 1H NMR. IR spectroscopy revealed that PzA coordinates with lanthanide(Ⅲ) ions and methanesulfonate coordinates via oxygen atoms in a non-equivalent manner. In preliminary catalytic studies, these compounds were active in styrene polymerization that used MAO as a cocatalyst with an activity of 12.3 kg PS mol Sm-1h-1. Differential scanning calorimetry (DSC) of polystyrene showed that the polymer was mainly atactic.

  10. Mutations induced by 1,3-butadiene metabolites, butadiene diolepoxide, and 1,2,3,4-diepoxybutane at the Hprt locus in CHO-K1 cells.

    Science.gov (United States)

    Lee, Dong-Hyun; Kim, Tae-Ho; Lee, Sun-Young; Kim, Hyun-Jo; Rhee, Seung Keun; Yoon, ByoungSu; Pfeifer, Gerd P; Lee, Chong-Soon

    2002-12-31

    Butadiene (BD) is an important industrial chemical that is classified as a probable human carcinogen. Butadiene diolepoxide (BDE) and 1,2,3,4-diepoxybutane (DEB) are metabolites of carcinogenic BD and contain the DNA-reactive one and two epoxides, respectively. In this study, the mutation frequencies and mutation spectra that are induced by BDE and DEB have been investigated at the hprt locus in CHO-K1 cells. The BDE- and DEB-treated CHO-K1 cells were allowed to grow for several days, then seeded in a medium that contained 6-thioguanine in order to select the hprt mutants. BDE exhibited the mutagenic activity at concentrations that were approximately 100-times higher than DEB. The mutation spectra for BDE and DEB were determined by a reverse transcription-polymerase chain reaction of hprt mRNA, which was followed by automatic DNA sequencing of the PCR products. The mutational spectrum for BDE was exon deletions (16/41), G x C --> A x T transitions (11/41), and A x T --> G x C transitions (5/41). The mutational spectrum for DEB was exon deletions (15/39), G x C --> A x T transitions (11/39), and A x T --> T x A transversions (5/39). The most common base substitution that was induced by both BDE and DEB was G x C --> A x T transitions. The sites of the single base substitutions that were induced by BDE and DEB were guanine and adenine, which was consistent with the DNA adduct profiles. The high frequencies of the exon deletions by each metabolite occurred in the regions of exons 2, 3, or 4. These data indicate that BDE and DEB are mutagenic carcinogens by forming DNA adducts at the site of adenine and guanine, and inducing large exon deletions and single base substitutions. PMID:12521305

  11. Development of recycled plastic composites for structural applications from CEA plastics

    Science.gov (United States)

    Bhalla, Agrim

    Plastic waste from consumer electronic appliances (CEAs) such as computer and printer parts including Polystyrene (PS), Acrylonitrile Butadiene Styrene (ABS), Polystyrene (PS) and PC/ABS were collected using handheld FTIR Spectrophotometer. The blends of these plastics with High Density Polyethylene (HDPE) are manufactured under special processing conditions in a single screw compounding injection molding machine. The blends are thermoplastics have high stiffness and strength, which may enhance the mechanical properties of HDPE like tensile modulus, ultimate tensile strength, tensile break and tensile yield. These composites have a potential to be used for the future application of recycled plastic lumber, thus replacing the traditional wood lumber.

  12. A low-cost lead-acid battery with high specific-energy

    Indian Academy of Sciences (India)

    S K Martha; B Hariprakash; S A Gaffoor; D C Trivedi; A K Shukla

    2006-01-01

    Lightweight grids for lead-acid battery grids have been prepared from acrylonitrile butadiene styrene (ABS) copolymer followed by coating with lead. Subsequently, the grids have been electrochemically coated with a conductive and corrosion-resistant layer of polyaniline. These grids are about 75% lighter than those employed in conventional lead-acid batteries. Commercial-grade 6V/3.5Ah (C20-rate) lead-acid batteries have been assembled and characterized employing positive and negative plates constituting these grids. The specific energy of such a lead-acid battery is about 50 Wh/kg. The batteries can withstand fast charge-discharge duty cycles.

  13. Cooling simulation of plastic injection molding

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Analyses the cooling of mold and plastic part during injectionmolding and the continued cooling of plastic part after being ejected from mold using the heat transfer theory and Boundary Element Method (BEM) to predict the temperature distribution in both mold and plastic part,and presents the experiments carried out with plates of ABS (Acrylonitrile-Butadiene-Styrene) to verify the validity of the cooling analysis software used to simulate the temperature distribution in ABS plate parts, and concludes that the analysis software agree qualitatively well with actual experimental findings.

  14. Charpy Impact Test on Polymeric Molded Parts

    Directory of Open Access Journals (Sweden)

    Alexandra Raicu

    2012-09-01

    Full Text Available The paper presents the Charpy impact tests on the AcrylonitrileButadiene-Styrene (ABS polymeric material parts. The Charpy impact test, also known as the Charpy V-notch test, is a standardized strain rate test which determines the amount of energy absorbed by a material during fracture. This is a typical method described in ASTM Standard D 6110. We use for testing an Instron - Dynatup equipment which have a fully integrated hardware and software package that let us capture load information at very high speed from the impact tests.

  15. Effect of Pd ions in the chemical etching solution

    Institute of Scientific and Technical Information of China (English)

    Guixiang Wang; Ning Li; Deyu Li

    2007-01-01

    The acrylonitrile-butadiene-styrene (ABS) surface was etched by dipping it into chromic acid-sulfuric acid containing a trace amount of palladium. The surface roughness, activity, and valence bond were characterized by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). The results showed that with the increase of Pd concentration in the etching solution the ABS surface roughness reduced. The ratio of O to C increases and forms a large amount of O=C-O functional groups by dipping into Pd contained etching solution, thus the amount of colloids palladium adsorption increases. The carboxyl group acts as the adsorption site for the Pd/Sn catalyst.

  16. Production of super-smooth articles

    Energy Technology Data Exchange (ETDEWEB)

    Duchane, D.V.

    1981-05-29

    Super-smooth rounded or formed articles made of thermoplastic materials including various poly(methyl methacrylate) or acrylonitrile-butadiene-styrene copolymers are produced by immersing the articles into a bath, the composition of which is slowly changed with time. The starting composition of the bath is made up of at least one solvent for the polymer and a diluent made up of at least one nonsolvent for the polymer and optional materials which are soluble in the bath. The resulting extremely smooth articles are useful as mandrels for laser fusion and should be useful for a wide variety of other purposes, for example lenses.

  17. 3D‐Printing inside the Glovebox: A Versatile Tool for Inert‐Gas Chemistry Combined with Spectroscopy

    OpenAIRE

    Lederle, Felix; Kaldun, Christian; Namyslo, Jan C.; Hübner, Eike G.

    2016-01-01

    3D‐Printing with the well‐established ‘Fused Deposition Modeling’ technology was used to print totally gas‐tight reaction vessels, combined with printed cuvettes, inside the inert‐gas atmosphere of a glovebox. During pauses of the print, the reaction flasks out of acrylonitrile butadiene styrene were filled with various reactants. After the basic test reactions to proof the oxygen tightness and investigations of the influence of printing within an inert‐gas atmosphere, scope and limitations o...

  18. Inhalation developmental toxicology studies of 1,3-butadiene in the rat: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hackett, P.L.; Sikov, M.R.; Mast, T.J.; Brown, M.G.; Buschbom, R.L.; Clark, M.L.; Decker, J.R.; Evanoff, J.J.; Rommereim, R.L.; Rowe, S.E.; Westerberg, R.B.

    1987-11-01

    Maternal toxicity, reproductive performance and developmental toxicology were evaluated in Sprague-Dawley-derived rats during and following 6 hours/day, whole-body, inhalation exposures to 0, 40, 200, and 1000 ppM of 1,3-butadiene. The female rats (Ns = 24 to 28), which had mated with unexposed males, were exposed to the chemical from 6 through 15 dg and sacrificed on 20 dg. Maternal animals were weighed prior to mating and on 0, 6, 11, 16 and 20 dg; the rats were observed for mortality, morbidity and signs of toxicity during exposure and examined for gross tissue abnormalities at necropsy. Live fetuses were weighed and subjected to external, visceral and skeletal examinations to detect growth retardation and morphologic anomalies. There were no significant differences among treatment groups in maternal body weights or extragestational weights of rats exposed to 1,3-butadiene concentrations of 40 or 200 ppM, but, in animals exposed to 1000 ppM, significantly depressed body weight gains were observed during the first 5 days of exposure and extragestational weight gains tended to be lower than control values. These results, and the absence of clinical signs of toxicity, were considered to indicate that there was no maternal toxicity at exposure levels of 200 ppM or lower. The percentage of pregnant animals and the number of litters with live fetuses were unaffected by treatment. Under the conditions of this exposure regimen, there was no evidence for a teratogenic response to 1,3-butadiene exposure.

  19. Analysis and optimization of nitrile butadiene rubber sealing mechanism of ball valve

    Institute of Scientific and Technical Information of China (English)

    Xue-Guan SONG; Lin WANG; Young-Chul PARK

    2009-01-01

    An approach for analyzing and optimizing sealing mechanism of ball valve made of nitrile butadiene mbber(NBR) with finite element method was presented. The Mooney-Rivlin hyperelastic material model was chosen to characterize NBR sealing, as it has been recommended in the similar applications. That is, NBR sealing was modeled as incompressible hyperelasticity, as well as the assumption of isotropic flow. The results illustrate the structural pressure and contact pressure on the contact surface, which shows that the NBR sealing mechanism is very suitable for sealing after dimension optimization.

  20. 1,3-Butadiene hydrogenation on pd-supported systems: geometric effects

    Directory of Open Access Journals (Sweden)

    Souza P.R.N.

    2002-01-01

    Full Text Available A strong metal support interaction (SMSI effect was observed on Pd/Nb2O5 and Pd/TiO2 catalysts, and it produces small, exposed Pd ensembles. A decrease in the trans/cis 2-butene ratio was observed after reduction at 773 K. Selectivity changes were ascribed to the decoration model. Theoretical models were developed based on semi-empirical molecular-orbital calculations for 1,3-butadiene and Pd n clusters. Experimental results are in agreement with our theoretical model, which proposes a greater stabilization of the cisoid intermediate on small Pd ensembles.

  1. Self-Assembled Poly(butadiene)-b-Poly(ethylene oxide) Polymersomes as Paclitaxel Carriers

    OpenAIRE

    Li, Shuliang; Byrne, Belinda; Welsh, JoEllen; Palmer, Andre F.

    2007-01-01

    In this work, self-assembled poly(butadiene)-b-poly(ethylene oxide) (PB-PEO) polymersomes (polymer vesicles) and worm micelles were evaluated as paclitaxel carriers. Paclitaxel was successfully incorporated into PB-PEO polymersomes and worm micelles. The loading capacity of paclitaxel inside PB-PEO colloids ranged from 6.7-13.7% w/w, depending on the morphology of copolymer colloids and the molecular weight of diblock copolymer. Paclitaxel loaded OB4 (PB219-PEO121) polymersome formulations we...

  2. Study Tensile Strength and Wear Rate for Unsaturated Polyester Resin and Nitrile butadiene Rubber Polymer Blend

    Directory of Open Access Journals (Sweden)

    Entihaa G. Daway

    2015-06-01

    Full Text Available Binary polymer blend was prepared by mechanical mixing method of unsaturated polyester resin with Nitrile Butadiene Rubber (NBR with different weight ratios (0, 5, 10 and 15 % of (NBR. Tensile characteristics and wear rates of these blends were studied for all mixing ratios. The microstructure of fracture surfaces of the prepared samples were investigated by optical microscope. The results were showed that strain rates of the resin material increase after blending it with rubber while the ultimate tensile strength and Young’s modulus values of it will decrease. It is also noticed that the wear rate of resin decreases with increasing of (NBR content.

  3. Studies on Macro—kinetics of Gas Phase Polymerization of Butadiene with Rare—earch Catalyst

    Institute of Scientific and Technical Information of China (English)

    FANGDonyu; SUNJianzhong; 等

    2002-01-01

    The study of the kinetics of gas phase polymerization of butadiene with heterogeneous catalyst based on neodymium(Nd) was carried out.The effects of reaction temperature,reaction pressure,dispersing medium, and types of catalyst on kinetics of polymerization were investigated .A kinetic model with two kinds of active sites was proposed.The results show that the effects of the reaction temperature and the types of dispersing medium and catalyst on the kinetic performance of polymerization are significant,and that the combined model of first and second order decay of active site of catalyst can be used to describe the phenomena.

  4. Ionic polymer-metal composite actuators employing sulfonated poly (styrene-ethylene-butylene-styrene) as ionic-exchange membranes

    Science.gov (United States)

    Wang, Xuan-Lun; Oh, Il-Kwon; Lu, Jun; Ju, Jin-Hun; Lee, Sun-Woo

    2007-07-01

    There is growing interest in biomimetic motions by employing ionic polymer-metal composites (IPMCs) as the candidates for the fabrication of artificial muscle. However, the membrane materials currently used in IPMC actuators have been limited to a few commercially available perfluorinated ionic polymers, such as Nafion, and they suffer from several shortcomings among which their high cost presents a major obstacle for wide application. With excellent proton conductivity and high water uptake capacity, commercially available Sulfonated poly (styrene-ethylene-butylene-styrene) (SEBS) of low cost has been investigated for many years as a fuel cell membrane. Herein, we report the preparation of a novel IPMC actuator based on the sulfonated SEBS (SSEBS) membrane. The platinum electrodes of the SEBS actuators were obtained with electroless plating procedure, and the cation exchange with lithium was performed by soaking the composite membranes into a 1.5N LiCl solution. The surface and cross-sectional morphologies of the SSEBS actuators were observed by using scanning electron microscopy (SEM), which revealed that the platinum layer up to 8µm was deposited on the top and bottom surfaces of the SSEBS membrane. The electromechanical bending responses were investigated under alternating current excitations with various driving frequencies and voltage amplitudes, which showed high electrical strains under sinusoidal signal. The effect of the membrane thickness on the performance of the actuators was also addressed in this presentation. This kind of IPMC has great potentials for the applications in biomimetic sensors and actuators, which can be utilized to mimic the locomotion of fish and insects and can be applied to micro-robots and bio-medical devices as well.

  5. PREPARATION OF SULPHONATE-CONTAINING POLYMER PARTICLES VIA SEMI-CONTINUOUS EMULSION COPOLYMERIZAION OF STYRENE AND SODIUM STYRENE SULPHONATE

    Institute of Scientific and Technical Information of China (English)

    Ji-shuai Wang; Yun-shen Chen; Wei Deng; Cheng-you Kan

    2011-01-01

    Submicron-sized P(St-NaSS) latexes were prepared via a semi-continuous emulsion copolymerization of styrene (St) and sodium styrene sulphonate (NaSS) in the presence of anionic surfactant, in which NaSS aqueous solution and St were separately dropwise charged into the polymerization system at the same time. The hydrodynamic diameter of the latex particles was measured by dynamic light scattering (DSL) method, and the NaSS unit content of the purified copolymer by water extraction was calculated based on the elementary analysis. Results showed that the copolymerization could be performed smoothly with the monomer conversion more than 96% in the absence of crosslinker, and PNaSS homopolymer could be removed from the latex product by water extraction for 28 h. The weight loss in the water extraction tended to decrease and the NaSS unit content of the purified copolymer tended to increase with the increase of monomer feeding time, and both of them increased with the increase of NaSS/St mole ratio in the charge. The introduction of divinyl benzene (DVB) could decrease the weight loss in the water extraction and increase the NaSS unit content of the purified copolymer. When 25/75 mole ratio of NaSS/St and 11 mol% DVB of total NaSS and St were used in the recipe, and the monomer feeding time was 3 h in copolymerization, the NaSS unit content of the purified copolymer reached 7.31 mol%.

  6. 国内外丙烯腈供需现状和发展趋势%Global Supply & Demand Situation and Developing Trend of Acrylonitrile

    Institute of Scientific and Technical Information of China (English)

    吴宇红

    2012-01-01

    介绍了丙烯腈的国内外供需现状,分析了未来丙烯腈装置的投资计划及下游应用领域的需求情况,并预测了未来丙烯腈供需状况。估计到2015年全球丙烯腈产能将出现过剩,投资还需谨慎。%The global supply and demand situation of acrylinitrile was introduced.Based on anaysis of acrylinitrile plant investment plans and demand situation of downstream application filelds,the supply and demand situation of acrylonitrile in the future was predicted.It is predicted that global acrylonitrile capability would be surplus by 2015,so investment on acrylonitrile needs discretion.

  7. Prediction of Phase Behavior for Styrene/CO2/Polystyrene Mixtures

    Institute of Scientific and Technical Information of China (English)

    吴家龙; 潘勤敏; 等

    2002-01-01

    A lattice fluid model,Sanchez-Lacombe equation,is used to predict the phase behavior for a styrene/CO2/polystyrene ternary system.The binary parameters involved in the equation were optimized using experimental data.Phase diagrams and the distribution coefficients of styrene between polymer phase and fluid phase are obtained over a wide rang of pressure,temperature and composition.The analysis of ternary phase diagrams indicates that this system at relatively high pressure or low temperature may display two-phase equilibrium,and at low pressures or high temperatures three-phase equilibrium may appear.The distribution coefficients of styrene between the fluid phase and the polymer phase increase asymptotically to unity when the concentration of styrene increases.The results provide thermodynamic knowledge for further exploitation of supercritical carbon dioxide assisted devolatilization and impregnation.

  8. PALLADIUM-CATALYZED OXIDATION OF STYRENE AND ALKENES IN PRESENCE OF IONIC LIQUIDS (WACKER REACTION)

    Science.gov (United States)

    The use of ionic liquids in various synthetic transformations is gaining significance due to the enhanced reaction rates, potential for recycling and compatibility with various organic compounds and organometallic catalysts. Palladium-catalyzed oxidation of styrene and other alk...

  9. Copolymerization of Styrene with N—phenylmaleimide by Rare Earth Coordination Catalysts

    Institute of Scientific and Technical Information of China (English)

    YanBingLU; WeiLinSUN; 等

    2002-01-01

    Copolymerization of styrene (St) with N-phenylmaleimide(NPMI) was studied with rare earth coordination catalyst Nd(naph)3-AlEts in toluene. Characterization of the copolymers showed that the copolymers possess an alternating structure.

  10. A comprehensive review of occupational and general population cancer risk: 1,3-Butadiene exposure-response modeling for all leukemia, acute myelogenous leukemia, chronic lymphocytic leukemia, chronic myelogenous leukemia, myeloid neoplasm and lymphoid neoplasm.

    Science.gov (United States)

    Sielken, Robert L; Valdez-Flores, Ciriaco

    2015-11-01

    Excess cancer risks associated with 1,3-butadiene (BD) inhalation exposures are calculated using an extensive data set developed by the University of Alabama at Birmingham (UAB) from an epidemiology study of North American workers in the styrene butadiene rubber (SBR) industry. While the UAB study followed SBR workers, risk calculations can be adapted to estimate both occupational and general population risks. The data from the UAB SBR study offer an opportunity to quantitatively evaluate the association between cumulative exposure to BD and different types of cancer, accounting for the number of tasks involving high-intensity exposures to BD as well as confounding associated with the exposures to the multiple other chemicals in the SBR industry. Quantitative associations of BD exposure and cancer, specifically leukemia, can be further characterized by leukemia type, including potential associations with acute myelogenous leukemia (AML), chronic lymphocytic leukemia (CLL), and chronic myelogenous leukemia (CML), and the groups of lymphoid and myeloid neoplasms. Collectively, these multiple evaluations lead to a comprehensive analysis that makes use of all of the available information and is consistent with the risk assessment goals of the USEPA and other regulatory agencies, and in line with the recommendations of the USEPA Science Advisory Board. While a range of cancer risk values can result from these multiple factors, a preferred case for occupational and general population risk is highlighted. Cox proportional hazards models are used to fit exposure-response models to the most recent UAB data. The slope of the model with cumulative BD ppm-years as the predictor variable is not statistically significantly greater than zero for CML, AML, or, when any one of eight exposure covariates is added to the model, for all leukemias combined. The slope for CLL is statistically significantly different from zero. The slope for myeloid neoplasms is not statistically

  11. Low metal loading catalysts used for the selective hydrogenation of styrene

    OpenAIRE

    Juan Badano; Cecilia Lederhos; Mónica Quiroga; Pablo L'Argentière; Fernando Coloma-Pascual

    2010-01-01

    A series of Group VIII metal catalysts was obtained for the semi-hydrogenation of styrene. Catalysts were characterized by Hydrogen Chemisorption, TPR and XPS. Palladium, rhodium and platinum low metal loading prepared catalysts presented high activity and selectivity (ca. 98%) during the semi-hydrogenation of styrene, being palladium the most active catalyst. The ruthenium catalyst also presented high selectivity (ca. 98%), but the lowest activity. For the palladium catalyst, the influence o...

  12. Styrene-maleic anhydride copolymerization in a recycle tubular reactor: reactor stability and product quality

    OpenAIRE

    Belkhiria, Sahbi; Meyer, Thierry; Renken, Albert

    1994-01-01

    A tubular recycle reactor was developed to ensure good homogeneity of concn. and temp. in the copolymn. of styrene and maleic anhydride. The compn. of the copolymer obtained is in good agreements with predicted values and the uniformity of compn. was measured for the entire mol.-wt. distribution. The characterization of the reactor (both hydrodynamic and stability) and the quality of the resulting polymer are presented herein. The limits of use of this reactor for the styrene-maleic anhydride...

  13. Dynamic and kinetic aspects of the adsorption of acrylonitrile on Si(001)-2x1

    International Nuclear Information System (INIS)

    Using scanning tunnelling microscopy (STM), photoelectron and photoabsorption spectroscopies, we have examined how acrylonitrile (H2C=CH-C≡N) reacts with the Si(001)-2x1 surface for coverages ranging from ∼1012 molecules/cm2 to ∼1014 molecules/cm2. At 300 K, in the very low coverage regime (below 1013 molecules/cm2), filled- and empty-state STM images show that the molecule bridges, via its β carbon and nitrogen ends, two silicon dangling bonds, across the trench separating two dimer rows. A cumulative-double-bond unit (C=C=N) is formed. The 300 K STM image results from the dynamic flipping of the molecule between two equivalent equilibrium positions, which can be seen when the molecular motion is slowed down at 80 K. For coverages larger than 1013 molecules/cm2, for which STM does not show ordered adsorption any more, the adsorption kinetics were observed in real-time using valence band photoemission and resonant Auger yield, associated with N 1s x-ray absorption spectroscopy (NEXAFS). At 300 K, these techniques point to a situation more complex than the one explored by STM at very low coverage. Three species (cyano-bonded, vinyl-bonded, and cumulative-double-bond species) are detected. Their distribution does not vary with increasing coverage. All dimerization-related surface states are quenched at saturation. The uptake rates versus coverage relationship points to the presence of a mobile precursor. Finally, the paper discusses a possible mechanism leading to the formation of cross-trench C=C=N unit at low coverage, and the reasons why the product branching ratio changes with increasing coverage

  14. Nanofibrous poly(acrylonitrile-co-maleic acid) membranes functionalized with gelatin and chitosan for lipase immobilization.

    Science.gov (United States)

    Ye, Peng; Xu, Zhi-Kang; Wu, Jian; Innocent, Christophe; Seta, Patrick

    2006-08-01

    Nanofibrous membranes with an average diameter of 100 and 180 nm were fabricated from poly(acrylonitrile-co-maleic acid) (PANCMA) by the electrospinning process. These nanofibrous membranes contain reactive groups which can be used to covalently immobilize biomacromolecules. Two natural macromolecules, chitosan and gelatin, were tethered on these nanofibrous membranes to fabricate dual-layer biomimetic supports for enzyme immobilization in the presence of 1-ethyl-3-(dimethyl-aminopropyl) carbodiimide hydrochloride (EDC)/N-hydroxyl succinimide (NHS). Lipase from Candida rugosa was then immobilized on these dual-layer biomimetic supports using glutaraldehyde (GA), and on the nascent PANCMA fibrous membrane using EDC/NHS as coupling agent, respectively. The properties of the immobilized lipases were assayed. It was found that there is an increase of the activity retention of the immobilized lipase on the chitosan-modified nanofibrous membrane (45.6+/-1.8%) and on the gelatin-modified one (49.7+/-1.8%), compared to that on the nascent one (37.6+/-1.8%). The kinetic parameters of the free and immobilized lipases, K(m) and V(max), were also assayed. In comparison with the immobilized lipase on the nascent nanofibrous membrane, there is an increase of the V(max) value for the immobilized lipases on the chitosan- and gelatin-modified nanofibrous membranes. Results also indicate that the pH and thermal stabilities of lipases increase upon immobilization. The residual activities of the immobilized lipases are 55% on the chitosan-modified nanofibrous membrane and 60% on the gelatin-modified one, after 10 uses. PMID:16584770

  15. Chitosan-tethered poly(acrylonitrile-co-maleic acid) hollow fiber membrane for lipase immobilization.

    Science.gov (United States)

    Ye, Peng; Xu, Zhi-Kang; Che, Ai-Fu; Wu, Jian; Seta, Patrick

    2005-11-01

    A protocol was used to prepare a dual-layer biomimetic membrane as support for enzyme immobilization by tethering chitosan on the surface of poly(acrylonitrile-co-maleic acid) (PANCMA) ultrafiltration hollow fiber membrane in the presence of 1-ethyl-3-(dimethylaminopropyl) carbodiimide hydrochloride (EDC)/N-hydroxylsuccin-imide (NHS). The chemical change of the chitosan-modified PANCMA membrane surface was confirmed with Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Lipase from Candida rugosa was immobilized on this dual-layer biomimetic membrane using glutaraldehyde (GA), and on the nascent PANCMA membrane using EDC/NHS as coupling agent. The properties of the immobilized enzymes were assayed and compared with those of the free one. It was found that both the activity retention of the immobilized lipase and the amount of bound protein on the dual-layer biomimetic membrane (44.5% and 66.5 mg/m2) were higher than those on the nascent PANCMA membrane (33.9% and 53.7 mg/m2). The kinetic parameters of the free and immobilized lipases, Km and Vmax, were also assayed. The Km values were similar for the immobilized lipases, while the Vmax value of the immobilized lipase on the dual-layer biomimetic membrane was higher than that on the nascent PANCMA membrane. Results indicated that the pH and thermal stabilities of lipase increased upon immobilization. The residual activity of the immobilized lipase after 10 uses was 53% on the dual-layer biomimetic membrane and 62% on the nascent PANCMA membrane. PMID:15919112

  16. Modeling contaminant transport and remediation at an acrylonitrile spill site in Turkey

    Science.gov (United States)

    Şengör, S. Sevinç; Ünlü, Kahraman

    2013-07-01

    The August 1999 earthquake in Turkey damaged three acrylonitrile (AN) storage tanks at a plant producing synthetic fiber by polymerization. A numerical modeling study was carried out to analyze the groundwater flow and contaminant (AN) transport at the spill site. This study presents the application of a numerical groundwater model to determine the hydrogeological parameters of the site, where such data were not available during the field surveys prior to the simulation studies. The two- and three-dimensional transient flow and transport models were first calibrated using the first 266 days of observed head and concentration data and then verified using the remaining 540-day observed data set. Off-site migration of the contaminant plume was kept under control within the site boundaries owing to the favorable geology of the site, the characteristics of the local groundwater flow regime and the pumping operations. As expected, the applied pump-and-treat system was effective at high-permeability zones, but not fully effective at low-permeability zones. The results of long-term simulations for unconfined aquifer showed that the size of the plume in the high permeability zone shrank significantly due to the dilution by natural recharge. However, in the low permeability zone, it was not significantly affected. The study showed that accurate and sufficient data regarding the source characteristics, concentration and groundwater level measurements, groundwater pumping rates and their durations at each of the extraction points involved in the pump-and-treat system along with the hydrogeological site characterization are the key parameters for successful flow and transport model calibrations.

  17. Modification of fiber properties through grafting of acrylonitrile to rayon by chemical and radiation methods

    Directory of Open Access Journals (Sweden)

    Inderjeet Kaur

    2013-11-01

    Full Text Available Fibrous properties of rayon has been modified through synthesis of graft copolymers of rayon with acrylonitrile (AN by chemical method using ceric ammonium nitrate (CAN/HNO3 as a redox initiator and gamma radiation mutual method. Percentage of grafting (Pg was determined as a function of initiator concentration, monomer concentration, irradiation dose, temperature, time of reaction and the amount of water. Maximum percentage of grafting (160.01% using CAN/HNO3 was obtained at [CAN] = 22.80 × 10−3 mol/L, [HNO3] = 112.68 × 10−2 mol/L and [AN] = 114.49 × 10−2 mol/L in 20 mL of water at 45 °C within 120 min while in case of gamma radiation method, maximum Pg (90.24% was obtained at an optimum concentration of AN of 76.32 × 10−2 mol/L using 10 mL of water at room temperature with total dose exposure of 3.456 kGy/h. The grafted fiber was characterized by FTIR, SEM, TGA and XRD studies. Swelling behavior of grafted rayon in different solvents such as water, methanol, ethanol, DMF and acetone was studied and compared with the unmodified rayon. Dyeing behavior of the grafted fiber was also investigated.

  18. SELECTIVE SEPARATION OF WATER—ETHANOL MIXTURE THROUGH COPOLYMERIC MEMBRANES.Ⅱ.ACRYLONITRILE AND MALEIC ANHYDRIDE COPOLYMERIC MEMBRANES

    Institute of Scientific and Technical Information of China (English)

    ZHangFuyao; ZhangYifeng; 等

    1993-01-01

    Acrylonitrile(AN) and maleic anhydride(MA) copolymer has been synthesized by radical polymerization using ammonium persulfate and sodium bisulfite as initiator.The pervaporation properties of the copolymeric membranes prepared have been investigated for the first time. The dependences of pervaporation characteristics on coplymer composition,feed concentration and operating temperature have been studied.In order to improve the separation properties of the copolymeric membranes,the membranes were hydrolyzed with 10 wt% soldium hydroxide or potassium hydroxide aqueous solution.The hydrolyzed membranes containing more than 0.069MA mol fraction showed higher tensile strength and separation properties than the original membranes.

  19. Mechanistic diversity of the van Leusen reaction applied to 6-ketomorphinans and synthetic potential of the resulting acrylonitrile substructures.

    Science.gov (United States)

    Schütz, Johannes; Windisch, Petra; Kristeva, Elka; Wurst, Klaus; Ongania, Karl-Hans; Horvath, Ulrike E I; Schottenberger, Herwig; Laus, Gerhard; Schmidhammer, Helmut

    2005-06-24

    Tosylmethyl isocyanide was used to convert 7,8-didehydro-6-ketomorphinans to 6,7-didehydromorphinan-6-carbonitriles with retainment of the 4,5-epoxy ring. However, ring opening occurred in the presence of NaH giving 5,6,7,8-tetradehydromorphinan-6-carbonitriles. Addition of nucleophiles such as Li diisopropylamide or Grignard reagents to the acrylonitrile substructure yielded ring-opened 5,6-didehydro products. Seven products were characterized by X-ray crystal structure analysis and revealed insight into the mechanistic diversity of the van Leusen reaction.

  20. Pre-irradiation induced emulsion co-graft polymerization of acrylonitrile and acrylic acid onto a polyethylene nonwoven fabric

    Science.gov (United States)

    Liu, Hanzhou; Yu, Ming; Ma, Hongjuan; Wang, Ziqiang; Li, Linfan; Li, Jingye

    2014-01-01

    A pre-irradiation induced emulsion co-graft polymerization method was used to introduce acrylonitrile and acrylic acid onto a PE nonwoven fabric. The use of acrylic acid is meant to improve the hydrophilicity of the modified fabric. The kinetics of co-graft polymerization were studied. The existence of polyacrylonitrile (PAN) and poly(acrylic acid) (PAAc) graft chains was proven by Fourier transform infrared spectroscopy (FTIR) analysis. The existence of the nitrile groups in the graft chains indicates that they are ready for further amidoximation and adsorption of heavy metal ions.

  1. Genotoxicity of styrene oligomers extracted from polystyrene intended for use in contact with food

    Directory of Open Access Journals (Sweden)

    Makoto Nakai

    2014-01-01

    Full Text Available Here, we conducted in vitro genotoxicity tests to evaluate the genotoxicity of styrene oligomers extracted from polystyrene intended for use in contact with food. Styrene oligomers were extracted with acetone and the extract was subjected to the Ames test (OECD test guideline No. 471 and the in vitro chromosomal aberration test (OECD test guideline No. 473 under good laboratory practice conditions. The concentrations of styrene dimers and trimers in the concentrated extract were 540 and 13,431 ppm, respectively. Extraction with acetone provided markedly higher concentrations of styrene oligomers compared with extraction with 50% ethanol aqueous solution, which is the food simulant currently recommended for use in safety assessments of polystyrene by both the United States Food and Drug Administration and the European Food Safety Authority. And these high concentrations of styrene dimers and trimers were utilized for the evaluation of genotoxicity in vitro. Ames tests using five bacterial tester strains were negative both in the presence or absence of metabolic activation. The in vitro chromosomal aberration test using Chinese hamster lung cells (CHL/IU was also negative. Together, these results suggest that the risk of the genotoxicity of styrene oligomers that migrate from polystyrene food packaging into food is very low.

  2. Surface modification of poly(styrene-b-(ethylene-co-butylene)-b-styrene) elastomer via photo-initiated graft polymerization of poly(ethylene glycol)

    Science.gov (United States)

    Li, Xiaomeng; Luan, Shifang; Yang, Huawei; Shi, Hengchong; Zhao, Jie; Jin, Jing; Yin, Jinghua; Stagnaro, Paola

    2012-01-01

    Poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) copolymer biomedical elastomer was covalently grafted with poly(ethylene glycol) methyl ether methacrylate (PEGMA) via a photo-initiated graft polymerization technique. The surface graft polymerization of SEBS with PEGMA was verified by ATR-FTIR and XPS. Effect of graft polymerization parameters, i.e., monomer concentration, UV irradiation time and initiator concentration on the grafting density was investigated. Comparing with the virgin SEBS film, the PEGMA-modified SEBS film presented an enhanced wettability and a larger surface energy. Besides, the surface grafting of PEGMA imparted excellent anti-platelet adhesion and anti-protein adsorption to the SEBS surface.

  3. Surface modification of poly(styrene-b-(ethylene-co-butylene)-b-styrene) elastomer via photo-initiated graft polymerization of poly(ethylene glycol)

    Energy Technology Data Exchange (ETDEWEB)

    Li Xiaomeng [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Luan Shifang, E-mail: sfluan@ciac.jl.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Yang Huawei; Shi Hengchong; Zhao Jie; Jin Jing [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Yin Jinghua, E-mail: yinjh@ciac.jl.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Stagnaro, Paola [Istituto per Io Studio delle Macromolecole, Consiglio Nazionale delle Ricerche, Via de Marini 6, 16149 Genova (Italy)

    2012-01-15

    Poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) copolymer biomedical elastomer was covalently grafted with poly(ethylene glycol) methyl ether methacrylate (PEGMA) via a photo-initiated graft polymerization technique. The surface graft polymerization of SEBS with PEGMA was verified by ATR-FTIR and XPS. Effect of graft polymerization parameters, i.e., monomer concentration, UV irradiation time and initiator concentration on the grafting density was investigated. Comparing with the virgin SEBS film, the PEGMA-modified SEBS film presented an enhanced wettability and a larger surface energy. Besides, the surface grafting of PEGMA imparted excellent anti-platelet adhesion and anti-protein adsorption to the SEBS surface.

  4. Thermodynamic calculations for molecules with asymmetric internal rotors--application to 1,3-butadiene.

    Science.gov (United States)

    Wong, Bryan M; Raman, Sumathy

    2007-03-01

    We present quantum mechanical partition functions, free energies, entropies, and heat capacities of 1,3-butadiene derived from ab initio calculations. Our technique makes use of a reaction path-like Hamiltonian to couple all 23 vibrational modes to the large-amplitude torsion, which involves heavy asymmetric functional groups. Ab initio calculations were performed at the B3LYP, MP2, and CCSD(T) levels of theory and compared with experimental values as a reference case. By using the ab initio potentials and projected frequencies, simple perturbative expressions are presented for computing the couplings of all the vibrational modes to the large-amplitude torsion. The expressions are particularly suited for programming in the new STAR-P software platform which automatically parallelizes our codes with distributed memory via a familiar MATLAB interface. Using the efficient parallelization scheme of STAR-P, we obtain thermodynamic properties of 1,3-butadiene for temperatures ranging from 50 to 500 K. The free energies, entropies, and heat capacities obtained from our perturbative formulas are compared with conventional approximations and experimental values found in thermodynamic tables. PMID:17226834

  5. Quantum dynamics study of singlet-triplet transitions in s-trans-1,3-butadiene

    Science.gov (United States)

    Nikoobakht, Behnam; Köppel, Horst

    2016-05-01

    The intersystem crossing dynamics of s-trans-1,3-butadiene in its lowest singlet and triplet states is studied theoretically, employing a fully quantal approach for the first time. The electronic states 21Ag, 11Bu, 13Bu and 13Ag, which interact vibronically and via the spin-orbit coupling are treated in the calculation, thus covering the lowest spin-forbidden electronic transitions. Up to five nuclear degrees of freedom, including out-of-plane dihedral angles are included in our investigation. The calculation of potential energy surfaces relies on the CASPT2 method, and the evaluation of spin-orbit coupling matrix elements using the full two-electron Breit-Pauli Hamiltonian is performed by utilizing the MRCI wavefunction. The latter dependence on the nuclear coordinates is included for the first time. An electronic population transfer on the sub-picosecond time scale due to intersystem crossing is obtained, a mechanism that can contribute to the singlet-triplet transitions in the electron energy loss spectrum of s-trans-1, 3-butadiene. It is found that the dependence of the spin-orbit coupling on the out-of-plane coordinates plays a dominant role in these singlet-triplet transitions. The amount of population transfer to the 13Ag and 13Bu states is roughly of the same order of magnitude.

  6. Exfoliated sodium-montmorillonite in nitrile butadiene rubber nanocomposites with good properties

    Institute of Scientific and Technical Information of China (English)

    WANG QingGuo; ZHANG XiaoHong; QIAO JinLiang

    2009-01-01

    We prepared and utilized a novel ultrafine fully-vulcanized powder nitrile butadiene rubber (UFPNBR)/ sodium montmorillonite (Na-MMT) nanocompound powder, in which nanoscale UFPNBR particles and nanoscale platelets of Na-MMT were isolated and stuck each other. When the UFPNBR/Na-MMT nano-compoud powder was mixed with crude nitrile butadiene rubber (NBR), UFPNBR particles could be easily dispersed in NBR matrix because of good compatibility, and nanoscale Na-MMT was also dis-persed well in NBR matrix due to the carrier aidance of UFPNBR particle, thus the NBR/UFPNBPJNa-MMT ternary nanocomposites adapting to industry was fabricated. X-ray diffraction test and scanning electron microscopy (SEM) observation indicated that nanoscale Na-MMT was dispersed well in NBR matrix. Compared with NBR/Na-MMT binary composites, NBR/UFPNBR/Na-MMT ternary nanocompo-sites have shorter vulcanization time and higher flame retardancy due to the exfoliated Na-MMT in NBR matrix.

  7. Ethanol-to-Butadiene Conversion over SiO2-MgO Catalysts: Synthesis-Structure-Performance Relationships

    NARCIS (Netherlands)

    Angelici, C.

    2015-01-01

    The work presented in this PhD Thesis provides new insights into the underlying reasons that make SiO2-MgO materials excellent catalysts for the ethanol-to-butadiene Lebedev process. In particular, the preparation technique of choice affects the structural properties of the resulting SiO2-MgO materi

  8. THE EFFECT OF ETHERS ON ALTERNATING COPOLYMERIZATION OF BUTADIENE AND PROPYLENE CATALYZED BY VANADIUM-ALUMINUM SYSTEM

    Institute of Scientific and Technical Information of China (English)

    SU Dan; YU Dingsheng; HU Liping; JIAO Shuke

    1988-01-01

    The effect of five ethers on alternating copolymerization of butadiene and propylene were investigated. It was found that under appropriate conditions, by adding ether into reaction system, the conversion could be increased by 10-20% and the catalytic efficiency doubled at -45℃. The interaction between ether and active center was also studied.

  9. Oxidative Dehydrogenation of n-Butenes to 1,3-Butadiene over Bismuth Molybdate and Ferrite Catalysts: A Review

    KAUST Repository

    Hong, Eunpyo

    2015-11-02

    1,3-Butadiene, an important raw material for a variety of chemical products, can be produced via the oxidative dehydrogenation (ODH) of n-butenes over multicomponent oxide catalysts based on bismuth molybdates and ferrites. In this review, the basic concept, reaction mechanism, and catalysts typically used in an ODH reaction are discussed. © 2015, Springer Science+Business Media New York.

  10. A New Biocatalyst for Production of Optically Pure Aryl Epoxides by Styrene Monooxygenase from Pseudomonas fluorescens ST

    OpenAIRE

    Di Gennaro, Patrizia; Colmegna, Andrea; Galli, Enrica; Sello, Guido; Pelizzoni, Francesca; Bestetti, Giuseppina

    1999-01-01

    We developed a biocatalyst by cloning the styrene monooxygenase genes (styA and styB) from Pseudomonas fluorescens ST responsible for the oxidation of styrene to its corresponding epoxide. Recombinant Escherichia coli was able to oxidize different aryl vinyl and aryl ethenyl compounds to their corresponding optically pure epoxides. The results of bioconversions indicate the broad substrate preference of styrene monooxygenase and its potential for the production of several fine chemicals.

  11. A New Biocatalyst for Production of Optically Pure Aryl Epoxides by Styrene Monooxygenase from Pseudomonas fluorescens ST

    Science.gov (United States)

    Di Gennaro, Patrizia; Colmegna, Andrea; Galli, Enrica; Sello, Guido; Pelizzoni, Francesca; Bestetti, Giuseppina

    1999-01-01

    We developed a biocatalyst by cloning the styrene monooxygenase genes (styA and styB) from Pseudomonas fluorescens ST responsible for the oxidation of styrene to its corresponding epoxide. Recombinant Escherichia coli was able to oxidize different aryl vinyl and aryl ethenyl compounds to their corresponding optically pure epoxides. The results of bioconversions indicate the broad substrate preference of styrene monooxygenase and its potential for the production of several fine chemicals. PMID:10347083

  12. Emissions of benzene, toluene, xylenes and 1,3-butadiene from a representative portion of the Australian car fleet

    Science.gov (United States)

    Duffy, B. L.; Nelson, P. F.; Ye, Y.; Weeks, I. A.; Galbally, I. E.

    The exhaust emissions of the air toxics benzene, toluene, total xylenes and 1,3-butadiene have been measured in the cold transient (CT), cold stabilised (CS) and hot transient (HT) phases of the Australian Design Rule (ADR) 37/00 Drive cycle for 19 pre-1986 non-catalyst-equipped vehicles fuelled with leaded petrol, and 56 post-1985 catalyst-equipped vehicles fuelled with unleaded petrol. Per vehicle exhaust emissions, averaged over the 3 phases of the ADR 37/00 test, of 1,3-butadiene, benzene, toluene, and total xylenes for the older vehicles were about 19, 139, 240 and 164 mg km -1 respectively. The corresponding emissions for the better 46 of the 56 post-1985 vehicles tested were 1.7, 28.1, 36.4, and 27.0 mg km- 1 respectively. The remaining 10 high polluting post-1985 vehicles had emission rates comparable to those vehicles not equipped with catalytic converters, suggesting that about 20% of post-1985 vehicles have malfunctioning or poorly operating catalysts. For the non-catalyst-equipped, pre-1986 vehicles, CS and HT emissions were about 60% of the CT emissions. For the better 46 post-1985 vehicles, average emissions during the CS and HT phases were about 20-25%, 12-16%, 11-14%, and 7-13% of the CT emissions for benzene, toluene, the xylenes, and 1,3-butadiene, respectively. The emissions from a small number (9) of non-catalyst-equipped, pre-1986 vehicles were determined using unleaded and leaded petrol. The emissions of all four target compounds were found to be significantly lower when unleaded petrol was substituted for leaded petrol. The greatest percentage emission reductions were observed for the CT phase, ranging from 25% for 1,3-butadiene to 35% for toluene. Emissions averaged over the 3 phases were reduced by 10% for 1,3-butadiene and by 16-18% for the aromatic compounds. Per vehicle total (heat build and hot soak) evaporative emissions of 1,3-butadiene, benzene, toluene and xylenes from pre-1985 vehicles during the Sealed Housing Evaporative

  13. The Protective Value of Hesperidin in Mitigating the Biochemical Perturbations and Trace Element alterations induced by Acrylonitrile in Rats

    Directory of Open Access Journals (Sweden)

    N. M. Abdallah*, N. E. Amien**, M. R. Mohamed*, A. S. Nada**, M. A. Mohamed

    2013-07-01

    Full Text Available Objective: Acrylonitrile (a chemical pollutant has been reported to induce harmful effects in humans. Therefore, this study was designed to evaluate the protective effects of hesperidin, a natural bioflavonoid, against the toxicity induced by acrylonitrile (AN in rats. Material&Methods: This study includes determination of serum total scavenger capacity “TSC”, liver enzymes (aspartate transaminase “ASAT”, alanine transaminase “ALAT” and alkaline phosphatase “ALP”, total proteins, albumin, glucose, creatinine, urea and lipid profile. Moreover, liver and kidney homogenate glutathione content “GSH”, catalase, superoxide dismutase “SOD”, glutathione peroxidase “GPx”, malondialdehyde “MDA” and some minerals were estimated. Results: revealed that administration of AN (orally 50mg/ kg b.wt. induced alterations in TSC level as well as liver, kidney and lipid profiles. In addition, a decrease in GSH-content and catalase, SOD and GPx activities was observed with an increase in MDA levels in both liver and kidney. There was disturbance in certain minerals such as Cu, Zn, Fe, Se, Ca, Mg and Mn. Conclusion: particularly, Hesperidin administration (orally 200 mg/kg b.wt. ameliorates the oxidative stress induced by AN, consistent with the reported antioxidant activity of hesperidin

  14. Dye-sensitized solar cell with poly(acrylic acid-co-acrylonitrile)-based gel polymer electrolyte

    International Nuclear Information System (INIS)

    Highlights: ► A nontoxic, easily synthesized poly(acrylic acid-co-acrylonitrile) showed suitable transmittance for dye-sensitized solar cell. ► A cell with relatively large active area fabricated with this polymer material showed acceptable efficiency. ► The gel polymer matrix affected the charge recombination, I3− diffusion, double layer capacitance, and electron lifetime in the cell. - Abstract: A non-conducting, nontoxic poly(acrylic acid-co-acrylonitrile) (PAA) was prepared and used as a supporting matrix for the electrolyte of dye-sensitized solar cells (DSSCs). DSSCs of active area 0.80 cm × 1.10 cm fabricated with PAA, 0.5 M LiI, 0.05 M I2, 0.5 M 3-tert-butylpyridine, and 0.1 M 1-methyl-3-propylimidazolium iodide in 3-methoxypropionitrile solvent showed an average solar energy conversion efficiency of 1.61% under simulated sunlight illumination of 100 mW cm−2, AM 1.5. The effects of the gel polymer matrix on the electrochemical properties of DSSCs were studied using the electrochemical impedance spectroscopy. Relative to the non-gel reference cells, the results showed a decrease in charge recombination, ionic diffusion, and double layer capacitance and an increase in electron lifetime. These results could play an important role in determining the future direction for the development of high-performance gel polymer electrolytes.

  15. Controlled Release of Imidacloprid from Poly Styrene-Diacetone - Nanoformulation

    Science.gov (United States)

    Qian, Kun; Guo, Yanzhen; He, Lin

    2012-01-01

    Imidacloprid is a neonicotinoids insecticide, which is important for the cash crops such as tomato, rape and so on. The conventional formulation does not only increase the loss of pesticide but also leads to environmental pollution. Controlled-release formulations of pesticide are highly desirable not only for attaining the most effective utilization of the pesticide, but also for reducing environmental pollution. Pesticide imidacloprid was incorporated in poly (styrene-diacetone crylamide)-based formulation to obtain controlled release properties, and the imidacloprid nanocontrolled release formulation was characterized by infrared (IR) and field emission scanning electron microscope (FESEM). Factors related to loading efficiency, swelling and release behaviors of the formulation were investigated. It showed that the loading efficiency could reach about 40% (w/w). The values for the diffusion exponent "n" were in the range of 0.31-0.58, which indicated that the release of imidacloprid was diffusion-controlled. The time taken for 50% of the active ingredient to be released into water, T50, was also calculated for the comparison of formulations in different conditions. The results showed that the formulation with higher temperature and more diacetone crylamide had lower value of T50, which means a quicker release of the active ingredient. This study highlighted some pieces of evidence that improved pesticide incorporation and slower release were linked to potential interactions between the pesticide and the polymer.

  16. Aqueous Tape Casting Process with Styrene-acrylic Latex Binder

    Institute of Scientific and Technical Information of China (English)

    CUI Xue-min; OUYANG Shi-xi; HUANG Yong; YU Zhi-yong; ZHAO Shi-ke; WANG Chang-an

    2004-01-01

    A commercial styrene-acrylic latex binder has been investigated as a good binder for aqueous Al2O3 suspensions tape-casting process. This paper focuses on the forming film mechanism of latex binder, the rheological behaviors of the suspensions, physical properties of green tapes and drying process of aqueous slurries with latex binder system. The drying process of the alumina suspensions is shown to follow a two-stage mechanism (the first stage: evaporation controlled process; and the second stage: diffusion controlled process). During the drying stage of the suspensions, the compressive force presses the latex particles and makes them be distorted, which results in cross-linking structure in contacted latex particles of the solidified tapes.A smooth-surface and high-strength green tape was fabricated by aqueous tape casting with latex binder system. The results from the SEM images of the crossing section microstructure of green tapes show that the latex is a very suitable binder for aqueous tape casting.

  17. A critical review finds styrene lacks direct endocrine disruptor activity.

    Science.gov (United States)

    Gelbke, Heinz-Peter; Banton, Marcy; Leibold, Edgar; Pemberton, Mark; Samson, Susan Leanne

    2015-01-01

    The European Commission lists styrene (S) as an endocrine disruptor based primarily on reports of increased prolactin (PRL) levels in S-exposed workers. The US Environmental Protection Agency included S in its list of chemicals to be tested for endocrine activity. Therefore, the database of S for potential endocrine activity is assessed. In vitro and in vivo screening studies, as well as non-guideline and guideline investigations in experimental animals indicate that S is not associated with (anti)estrogenic, (anti)androgenic, or thyroid-modulating activity or with an endocrine activity that may be relevant for the environment. Studies in exposed workers have suggested elevated PRL levels that have been further examined in a series of human and animal investigations. While there is only one definitively known physiological function of PRL, namely stimulation of milk production, many normal stress situations may lead to elevations without any chemical exposure. Animal studies on various aspects of dopamine (DA), the PRL-regulating neurotransmitter, in the central nervous system did not give mechanistic explanations on how S may affect PRL levels. Overall, a neuroendocrine disruption of PRL regulation cannot be deduced from a large experimental database. The effects in workers could not consistently be reproduced in experimental animals and the findings in humans represented acute reversible effects clearly below clinical and pathological levels. Therefore, unspecific acute workplace-related stress is proposed as an alternative mode of action for elevated PRL levels in workers. PMID:26406562

  18. Acrylonitrile potentiates hearing loss and cochlear damage induced by moderate noise exposure in rats

    International Nuclear Information System (INIS)

    The diversity of chemical and drugs that can potentiate noise-induced hearing loss (NIHL) has impeded efforts to predict such interactions. We have hypothesized that chemical contaminants that disrupt intrinsic antioxidant defenses hold significant risk for potentiating NIHL. If this is true, then acrylonitrile (ACN) would be expected to potentiate NIHL. ACN, one of the 50 most commonly used chemicals in the United States, is metabolized via two pathways that are likely to disrupt intrinsic reactive oxygen species (ROS) buffering systems: (1) it conjugates glutathione, depleting this important antioxidant rapidly; (2) a second pathway involves the formation of cyanide, which can inhibit superoxide dismutase. We hypothesized that moderate noise exposure, that does not produce permanent hearing loss by itself, could initiate oxidative stress and that ACN could render the inner ear more sensitive to noise by disrupting intrinsic antioxidant defenses. Temporary and persistent effects of ACN alone (50 mg/kg, sc 5 days), noise alone (95 or 97 dB octave band noise, 4 h/day for 5 days), or ACN in combination with noise were determined using distortion product otoacoustic emissions (DPOAEs) and compound action potential (CAP) amplitudes. Histopathological damage to hair cells resulting from these treatments was also investigated using surface preparations of the organ of Corti. Individually, neither ACN nor noise exposures caused any permanent hearing or hair cell loss; only a reversible temporary threshold shift was measured in noise-exposed animals. However, when given in combination, ACN and noise induced permanent threshold shifts (13-16 dB between 7 and 40 kHz) and a decrease in DPOAE amplitudes (up to 25 dB at 19 kHz), as well as significant outer hair cell (OHC) loss (up to 20% in the first row between 13 and 47 kHz). This investigation demonstrates that ACN can potentiate NIHL at noise levels that are realistic in terms of human exposure, and that the OHCs are the

  19. The effect of water absorption on the viscoelastic properties of poly(styrene-block-isobutylene-block-styrene) for use in biomedical applications

    Science.gov (United States)

    Fittipaldi, Mauro; Rodriguez, Luis A.; Grace, Landon R.

    2015-05-01

    The decrease in glass transition temperature and change in creep compliance due to water diffusion in a biocompatible thermoplastic elastomer was studied and quantified. Knowledge of the mechanical and viscoelastic performance of the styrene-isobutylene-styrene block (SIBS) copolymer is important to determine the feasibility of certain in-vivo applications. Furthermore, the deterioration in these types of properties due to the plasticizing effect of water must be well understood for long term usage. Samples were formed with an injection molding press and fully dried prior to immersion in distilled water at 37°C. Water diffusion kinetics were studied for four different SIBS copolymers of varying molecular weight and styrene content by measuring weight changes as a function of time. These gravimetric diffusion studies showed an inverse relationship between diffusivity and styrene content and molecular weight for the first thousand hours of immersion. Measurements of storage modulus, loss modulus, tangent delta, strain recovery and creep compliance were performed using a dynamic mechanical analyzer for the high molecular weight, high styrene content SIBS version at different absorbed water contents. A measurable and nearly linear decrease of the glass transition temperature and creep recovery with respect to water content was observed for the samples tested even at relatively low water content: an increase in water content of 0.27% correlated to a decrease of 4°C in glass transition temperature while a 0.16% weight increase corresponded to a 12.5% decrease in creep recovery. These quantified material properties restrict the use of SIBS in certain implantable operations that undergo cyclic strains, and in sterilization techniques that require high temperatures. As such, they are important to understand in order to determine the viability of in vivo usage of this biocompatible polymer.

  20. Investigation of the thermal and photochemical reactions of ozone with styrene in argon and krypton matrices

    Science.gov (United States)

    Coleman, Bridgett E.; Ault, Bruce S.

    2012-09-01

    The matrix isolation technique, combined with infrared spectroscopy and twin jet codeposition, has been used to characterize intermediates formed during the ozonolysis of styrene. Absorptions assigned to early intermediates grew in after warming the matrix from 19 K to 68 K in the twin jet krypton matrix experiments. A number of these absorptions have been assigned to the primary ozonide, formaldehyde-O-oxide Criegee intermediate, and secondary ozonide of styrene, transient species not previously observed for this system. In contrast, the room temperature reaction of ozone with styrene led to the observation of "late," stable products of this ozonolysis reaction. These product absorptions were observed after merged jet deposition, followed by cryogenic trapping in solid argon. Irradiation with λ ⩾ 220 nm of merged and twin jet argon matrices involving ozone led to O atom production and subsequent reaction with styrene. Identification of intermediates formed during the ozonolysis of styrene was further supported by 18O isotopic labeling experiments as well as theoretical density functional calculations at the B3LYP/6-311G++(d,2p) level.

  1. Fluorescence Efficiency and Visible Re-emission Spectrum of Tetraphenyl Butadiene Films at Extreme Ultraviolet Wavelengths

    CERN Document Server

    Gehman, V M; Rielage, K; Hime, A; Sun, Y; Mei, D -M; Maassen, J; Moore, D

    2011-01-01

    A large number of current and future experiments in neutrino and dark matter detection use the scintillation light from noble elements as a mechanism for measuring energy deposition. The scintillation light from these elements is produced in the extreme ultraviolet (EUV) range, from 60 - 200 nm. Currently, the most practical technique for observing light at these wavelengths is to surround the scintillation volume with a thin film of Tetraphenyl Butadiene (TPB) to act as a fluor. The TPB film absorbs EUV photons and reemits visible photons, detectable with a variety of commercial photosensors. Here we present a measurement of the re-emission spectrum of TPB films when illuminated with 128, 160, 175, and 250 nm light. We also measure the fluorescence efficiency as a function of incident wavelength from 120 to 250 nm.

  2. Fluorescence efficiency and visible re-emission spectrum of tetraphenyl butadiene films at extreme ultraviolet wavelengths

    Science.gov (United States)

    Gehman, V. M.; Seibert, S. R.; Rielage, K.; Hime, A.; Sun, Y.; Mei, D.-M.; Maassen, J.; Moore, D.

    2011-10-01

    A large number of current and future experiments in neutrino and dark matter detection use the scintillation light from noble elements as a mechanism for measuring energy deposition. The scintillation light from these elements is produced in the extreme ultraviolet (EUV) range, from 60 to 200 nm. Currently, the most practical technique for observing light at these wavelengths is to surround the scintillation volume with a thin film of tetraphenyl butadiene (TPB) to act as a fluor. The TPB film absorbs EUV photons and re-emits visible photons, detectable with a variety of commercial photosensors. Here we present a measurement of the re-emission spectrum of TPB films when illuminated with 128, 160, 175, and 250 nm light. We also measure the fluorescence efficiency as a function of incident wavelength from 120 to 250 nm.

  3. Conversion of far ultraviolet to visible radiation: absolute measurements of the conversion efficiency of tetraphenyl butadiene

    Science.gov (United States)

    Vest, Robert E.; Coplan, Michael A.; Clark, Charles W.

    Far ultraviolet (FUV) scintillation of noble gases is used in dark matter and neutrino research and in neutron detection. Upon collisional excitation, noble gas atoms recombine into excimer molecules that decay by FUV emission. Direct detection of FUV is difficult. Another approach is to convert it to visible light using a wavelength-shifting medium. One such medium, tetraphenyl butadiene (TPB) can be vapor-deposited on substrates. Thus the quality of thin TPB films can be tightly controlled. We have measured the absolute efficiency of FUV-to-visible conversion by 1 μm-thick TPB films vs. FUV wavelengths between 130 and 300 nm, with 1 nm resolution. The energy efficiency of FUV to visible conversion varies between 1% and 5%. We make comparisons with other recent results. Work performed at the NIST SURF III Synchrotron Ultraviolet Radiation Facility,.

  4. Tetraphenyl-butadiene films: VUV-Vis optical characterization from room to liquid argon temperature

    Science.gov (United States)

    Francini, R.; Montereali, R. M.; Nichelatti, E.; Vincenti, M. A.; Canci, N.; Segreto, E.; Cavanna, F.; Di Pompeo, F.; Carbonara, F.; Fiorillo, G.; Perfetto, F.

    2013-09-01

    A thin film of Tetraphenyl-butadiene (TPB) deposited onto the surface delimiting the active volume of the detector and/or onto the photosensor's optical window is the most common solution to down convert argon VUV scintillation light in current and planned liquid argon based experiments for dark matter searches and neutrino physics. Characterization of the main features of TPB coatings on different, commonly used substrates is reported, as a result of measurements at the specialized optical metrology labs of ENEA and University of Tor Vergata. Measured features include TPB emission spectra with lineshape and relative intensity variation recorded as a function of the film thickness and for the first time down to LAr temperature, as well as optical reflectance and transmittance spectra of the TPB coated substrates in the wavelength range of the TPB emission.

  5. Wavelength Shifting Efficiency of Tetraphenyl Butadiene (TPB) at Extreme Ultraviolet Wavelengths

    Science.gov (United States)

    Benson, Christopher; Orebi Gann, Gabriel; Gehman, Victor

    2015-10-01

    Tetraphenyl Butadiene (TPB) is a commonly used wavelength shifter (WLS) in neutrino and dark matter liquid noble gas scintillator detectors. Thin films of wavelength shifters are used to shift ultraviolet scintillation light into the visible spectrum for event reconstruction. The wavelength shifting efficiency of TPB is a function of the incident ultraviolet photon wavelength and is an important parameter for detector design, simulation and reconstruction. The wavelength shifting efficiency and emission spectrum has been previously measured down to 120 nm [Gehman et al., 2011]. To build liquid noble gas scintillator detectors with lighter elements (Ne, He) that use TPB as a WLS medium, the wavelength shifting efficiency must be known closer to 80 nm. This talk will present the current status and preliminary results from a set of measurements that will improve the precision of the efficiency of 120 nm, and extend the data to wavelengths as low as 45 nm.

  6. An ab initio potential function for the ν13 vibrational mode of 1,3-butadiene

    Science.gov (United States)

    Senent, M. L.

    1995-06-01

    The restricted potential of the ν13 torsional mode of 1,3-butadiene has been determined from ab initio calculations. The relative energy and geometry of the second rotamer were calculated with the optimized couple cluster method with double substitutions. This ab initio level provides that the second stable structure attaches to a gauche form situated at 140.8°. The potential energy function was obtained by fitting to a symmetry-adapted Fourier series the total electronic energies of several selected conformations. These energies were calculated by the Möller-Plesset perturbation theory up to the second order (MP2) with full and partial optimization of the geometry. Torsional Raman band positions and fundamental frequencies were determined from the periodic potentials with a good agreement with experimental data. The convenience of performing fully optimized calculations to determine the restricted function is also refuted.

  7. Gloves against mineral oils and mechanical hazards: composites of carboxylated acrylonitrile–butadiene rubber latex

    Science.gov (United States)

    Krzemińska, Sylwia; Rzymski, Władysław M.; Malesa, Monika; Borkowska, Urszula; Oleksy, Mariusz

    2016-01-01

    Resistance to permeation of noxious chemical substances should be accompanied by resistance to mechanical factors because the glove material may be torn, cut or punctured in the workplace. This study reports on glove materials, protecting against mineral oils and mechanical hazards, made of carboxylated acrylonitrile–butadiene rubber (XNBR) latex. The obtained materials were characterized by a very high resistance of the produced materials to oil permeation (breakthrough time > 480 min). The mechanical properties, and especially tear resistance, of the studied materials were improved after the addition of modified bentonite (nanofiller) to the XNBR latex mixture. The nanocomposite meets the requirements in terms of parameters characterizing tear, abrasion, cut and puncture resistance. Therefore, the developed material may be used for the production of multifunctional protective gloves. PMID:26757889

  8. Grafting titanium nitride surfaces with sodium styrene sulfonate thin films.

    Science.gov (United States)

    Zorn, Gilad; Migonney, Véronique; Castner, David G

    2014-09-01

    The importance of titanium nitride lies in its high hardness and its remarkable resistance to wear and corrosion, which has led to its use as a coating for the heads of hip prostheses, dental implants and dental surgery tools. However, the usefulness of titanium nitride coatings for biomedical applications could be significantly enhanced by modifying their surface with a bioactive polymer film. The main focus of the present work was to graft a bioactive poly(sodium styrene sulfonate) (pNaSS) thin film from titanium nitride surfaces via a two-step procedure: first modifying the surface with 3-methacryloxypropyltrimethoxysilane (MPS) and then grafting the pNaSS film from the MPS modified titanium through free radical polymerization. X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) were used after each step to characterize success and completeness of each reaction. The surface region of the titanium nitride prior to MPS functionalization and NaSS grafting contained a mixture of titanium nitride, oxy-nitride, oxide species as well as adventitious surface contaminants. After MPS functionalization, Si was detected by XPS, and characteristic MPS fragments were detected by ToF-SIMS. After NaSS grafting, Na and S were detected by XPS and characteristic NaSS fragments were detected by ToF-SIMS. The XPS determined thicknesses of the MPS and NaSS overlayers were ∼1.5 and ∼1.7 nm, respectively. The pNaSS film density was estimated by the toluidine blue colorimetric assay to be 260 ± 70 ng/cm(2). PMID:25280842

  9. Designing zeolite catalysts for size- and shape-selective reactions: Selective hydrogenation of acetylene in the presence of butadiene and ethylene

    Energy Technology Data Exchange (ETDEWEB)

    Corbin, D.R.; Abrams, L.; Bonifaz, C. (E.I. du Pont de Nemours Company, Wilmington, DE (USA))

    1989-02-01

    In the production of ethylene from the steam cracking of natural gas, small amounts of acetylene and butadiene are produced. Downstream, acetylene can present a hazard in a cryogenic separation process while nonselective hydrogenation removes acetylene as well as valuable ethylene and butadiene. With the aid of adsorption measurements, a selective hydrogenation catalyst has been designed. Small-pore zeolites, which serve as catalytic supports and provide reactant selective control, were ion-exchanged with Ni{sup 2+} and subsequently reduced. Compared to a commercial catalyst in which 60% of butadiene and all of the acetylene are hydrogenated, these new catalysts totally hydrogenate acetylene with only 10-20% hydrogenation of the butadiene and almost no hydrogenation of ethylene. To achieve selective hydrogenation, poisoning of the metal sites on the external zeolite surface is essential in order to obtain a product spectrum dominated by catalytic sites within the zeolite framework.

  10. Improvement of Slip Resistance of Rubber Sole by Halogenation

    Directory of Open Access Journals (Sweden)

    R. Mohan, S. Raja, G. Saraswathy, S. Mathivanan, B. N. Das

    2013-09-01

    Full Text Available Styrene-butadiene-styrene thermoplastic rubber soles known as TPR soles are commonly used as bottom sole in footwear. Styrene-butadiene-styrene is a block co polymer. In this co polymer, butadiene makes the elastomeric sole soft and elastic while styrene makes the material hard and tough. Among essential properties slip resistance is considered as an important property to avoid frequent accidents caused by slips and falls on slippery surfaces

  11. Recovery of Styrene in Residue Tar Discharged from Styrene Distillation Separation Process%苯乙烯蒸馏残焦油中粗品苯乙烯的回收工艺

    Institute of Scientific and Technical Information of China (English)

    杨运泉; 段正康; 刘文英

    2001-01-01

    Based on the characteristic that styrene can form ternary azeotrope with some special organic solvents and water,a new separation process for recovery of styrene in residue tar discharged from the bottom of styrene distillation tower has been developed.The recovery rate of styrene in the tar is nearly 92%;the mass fraction of crude product styrene is 98%.%利用苯乙烯能与某些特定溶剂及水形成三元共沸物的特点,开发出从苯乙烯蒸馏塔釜排放的残焦油中提取粗品苯乙烯的新工艺。苯乙烯回收率可达92%以上,粗品苯乙烯的含量在98%(质量分数)以上。

  12. Grafting of styrene onto poly(vinylidene fluoride) films by gamma irradiation

    International Nuclear Information System (INIS)

    Radiation induced grafting of styrene onto poly(vinylidene fluoride) (PVDF) was studied owing to the crescent interest in use of grafted films to produce membranes with ion exchange capability. A Cobalt-60 source was used, with doses of 5 and 10 kGy, at dose rate of 5 kGy.h-1, at room temperature, inert atmosphere and according to the simultaneous method. Solutions of styrene/toluene (1:1, v/v) and styrene/N,N-dimethylformamide (DMF) (1:1, v/v) were used. The films were characterized by FT-IR spectroscopy (Infrared Spectroscopy), Differential Scanning Calorimetry (DSC), Thermogravimetric Measurement (TG) and the degree of grafting (DOG) were calculated gravimetrically. Results shown that in studied conditions, DMF allow greatest DOG than toluene and that increasing the irradiation dose correspond an increase in DOG. Infrared and thermal analyses confirmed the presence in the grafted polymers. (author)

  13. Effects of surfactants on the properties of mortar containing styrene/methacrylate superplasticizer.

    Science.gov (United States)

    Negim, El-Sayed; Kozhamzharova, Latipa; Khatib, Jamal; Bekbayeva, Lyazzat; Williams, Craig

    2014-01-01

    The physical and mechanical properties of mortar containing synthetic cosurfactants as air entraining agent are investigated. The cosurfactants consist of a combination of 2% dodecyl benzene sodium sulfonate (DBSS) and either 1.5% polyvinyl alcohol (PVA) or 1.5% polyoxyethylene glycol monomethyl ether (POE). Also these cosurfactants were used to prepare copolymers latex: styrene/butyl methacrylate (St/BuMA), styrene/methyl methacrylate (St/MMA), and styrene/glycidyl methacrylate (St/GMA), in order to study their effects on the properties of mortar. The properties of mortar examined included flow table, W/C ratio, setting time, water absorption, compressive strength, and combined water. The results indicate that the latex causes improvement in mortar properties compared with cosurfactants. Also polymer latex containing DBSS/POE is more effective than that containing DBSS/PVA.

  14. Effects of Surfactants on the Properties of Mortar Containing Styrene/Methacrylate Superplasticizer

    Directory of Open Access Journals (Sweden)

    El-Sayed Negim

    2014-01-01

    Full Text Available The physical and mechanical properties of mortar containing synthetic cosurfactants as air entraining agent are investigated. The cosurfactants consist of a combination of 2% dodecyl benzene sodium sulfonate (DBSS and either 1.5% polyvinyl alcohol (PVA or 1.5% polyoxyethylene glycol monomethyl ether (POE. Also these cosurfactants were used to prepare copolymers latex: styrene/butyl methacrylate (St/BuMA, styrene/methyl methacrylate (St/MMA, and styrene/glycidyl methacrylate (St/GMA, in order to study their effects on the properties of mortar. The properties of mortar examined included flow table, W/C ratio, setting time, water absorption, compressive strength, and combined water. The results indicate that the latex causes improvement in mortar properties compared with cosurfactants. Also polymer latex containing DBSS/POE is more effective than that containing DBSS/PVA.

  15. Final Technical Report - Autothermal Styrene Manufacturing Process with Net Export of Energy

    Energy Technology Data Exchange (ETDEWEB)

    Trubac, Robert , E.; Lin, Feng; Ghosh, Ruma: Greene, Marvin

    2011-11-29

    The overall objectives of the project were to: (a) develop an economically competitive processing technology for styrene monomer (SM) that would reduce process energy requirements by a minimum 25% relative to those of conventional technology while achieving a minimum 10% ROI; and (b) advance the technology towards commercial readiness. This technology is referred to as OMT (Oxymethylation of Toluene). The unique energy savings feature of the OMT technology would be replacement of the conventional benzene and ethylene feedstocks with toluene, methane in natural gas and air or oxygen, the latter of which have much lower specific energy of production values. As an oxidative technology, OMT is a net energy exporter rather than a net energy consumer like the conventional ethylbenzene/styrene (EB/SM) process. OMT plants would ultimately reduce the cost of styrene monomer which in turn will decrease the costs of polystyrene making it perhaps more cost competitive with competing polymers such as polypropylene.

  16. Preparation and characteristics of acrylic acid/styrene composite plasma polymerized membranes

    International Nuclear Information System (INIS)

    Plasma polymerization has gained increasing interest for the deposition of functional plasma-polymerized membranes suitable for a wide range of applications on account of its advantageous features. In this work, acrylic acid/styrene composite plasma polymerized membranes were synthesized by plasma polymerization of a mixture of acrylic acid and styrene monomers in a low-frequency after-glow capacitively coupled plasma (CCP) discharge process. The structure and composition of the plasma polymerized membranes were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The results showed that the partial pressure ratio between acrylic acid (AA) and styrene (St), applied discharge power and the energy of the extracted particles have considerable effects on the structure and the content of functional groups of the deposited membranes.

  17. Entropic separation of styrene/ethylbenzene mixtures by exploitation of subtle differences in molecular configurations in ordered crystalline nanoporous adsorbents.

    Science.gov (United States)

    Torres-Knoop, Ariana; Heinen, Jurn; Krishna, Rajamani; Dubbeldam, David

    2015-03-31

    The separation of styrene/ethylbenzene mixture is of great importance in the petrochemical industry. Current technology uses distillation; this separation is difficult because of the small, 9 K, difference in the boiling points. An alternative separation method uses selective adsorption in nanoporous materials such as zeolites and metal-organic frameworks. Here we present a simulation screening study for the separation of styrene/ethylbenzene mixture by adsorptive means in nanoporous materials near pore saturation conditions. Under these conditions, different entropic mechanisms can dictate the separation process. Commensurate stacking has the best trade-off between selectivity and saturation capacity and offers a geometrical solution to the separation problem. MIL-47 has the right channel size and topology for styrene to exhibit commensurate stacking offering high capacity and selectivity for styrene over ethylbenzene. Out of all the screened structures, MIL-47 was found to be the best candidate for the separation of styrene/ethylbenzene mixture. PMID:25764506

  18. The use of poly(vinylpyridine-co-acrylonitrile) in polymer electrolytes for quasi-solid dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Li, Minyu [Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Feng, Shujing; Fang, Shibi; Xiao, Xurui; Li, Xueping; Zhou, Xiaowen; Lin, Yuan [Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080 (China)

    2007-04-01

    Poly(vinylpyridine-co-acrylonitrile) (P(VP-co-AN)) was used to form polymer electrolytes for dye-sensitized solar cells (DSSCs). The effects of P(VP-co-AN) on the photovoltaic performances of DSSCs have been investigated with nonaqueous electrolytes containing alkali-iodide and iodine. It was found that the effect of P(VP-co-AN) on V{sub oc} closely related to its amount in the electrolyte. Lower amount of P(VP-co-AN) was benefit for the construction of a solar cell containing P(VP-co-AN) with higher energy conversion efficiency. Chemically crosslinking solidification with backbone polymer P(VP-co-AN) amount of 3% fabricated quasi-solid DSSCs with 10% increased conversion efficiencies with relative to that of the initial liquid DSSCs. (author)

  19. The use of poly(vinylpyridine-co-acrylonitrile) in polymer electrolytes for quasi-solid dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Poly(vinylpyridine-co-acrylonitrile) (P(VP-co-AN)) was used to form polymer electrolytes for dye-sensitized solar cells (DSSCs). The effects of P(VP-co-AN) on the photovoltaic performances of DSSCs have been investigated with nonaqueous electrolytes containing alkali-iodide and iodine. It was found that the effect of P(VP-co-AN) on V oc closely related to its amount in the electrolyte. Lower amount of P(VP-co-AN) was benefit for the construction of a solar cell containing P(VP-co-AN) with higher energy conversion efficiency. Chemically crosslinking solidification with backbone polymer P(VP-co-AN) amount of 3% fabricated quasi-solid DSSCs with 10% increased conversion efficiencies with relative to that of the initial liquid DSSCs

  20. STUDY ON THE GASEOUS PRODUCTS OF HIGH TEMPERATURE PYROLYSIS OF ACRYLONITRILE POLYMERS BY ON-LINE FTIR METHOD

    Institute of Scientific and Technical Information of China (English)

    ZHAO Genxiang; CHEN Bangjie

    1987-01-01

    The gaseous products of high temperature pyrolysis (300℃ to 960℃) of acrylonitrile polymers were measured continuously under nitrogen atnosphere by on-line Fourier Transform Infrared Spectroscopic method (FTIR). From the variations of characteristic peaks it was found that the nitrogen of macromolecules evolved were mainly in the form of hydrogen cyanide and ammonia. During the pyrolysis amorphous carbonaceous element was formed, and crosslinked to form network structure. Three kinds of samples were used for comparison. The experimental results show that the gaseous products of volatile small molecules were HCN, NH3, CH4, C2H6 and cyanide. CO and CO2 were also formed when copolymers of PAN were thermally pyrolyzed.

  1. Pressure induced graft-co-polymerization of acrylonitrile onto Saccharum cilliare fibre and evaluation of some properties of grafted fibre

    Indian Academy of Sciences (India)

    A S Singha; Anjali Shama; Vijay Kumar Thakur

    2008-02-01

    In the present work, graft co-polymerization of acrylonitrile (AN) onto Saccharum cilliare fibre has been carried out in the presence of potassium persulphate and ferrous ammonium sulphate (FAS–KPS) as redox initiator. The reactions were carried out under pressure in an autoclave. Various reaction parameters such as pressure, time, pH, concentrations of initiator and monomer were optimized to get maximum graft yield (35.59%). Grafted and ungrafted Saccharum cilliare fibres were then subjected to evaluation of some of their properties like swelling behaviour in different solvents, moisture absorbance under different humidity levels, water uptake and resistance towards chemicals such as hydrochloric acid and sodium hydroxide. The characterization of the graft copolymers were carried out by FTIR spectrophotometer, X-ray diffraction (XRD) and scanning electron microscopic (SEM) studies.

  2. Use of Yb-based catalyst for AGET ATRP of acrylonitrile to simultaneously control molecular mass distribution and tacticity.

    Science.gov (United States)

    Ma, Jing; Chen, Hou; Zhang, Min; Wang, Chunhua; Zhang, Ying; Qu, Rongjun

    2012-08-01

    Yb-based catalyst was used for the first time for atom transfer radical polymerization using activators generated by electron transfer (AGET ATRP) of acrylonitrile (AN) with 2-bromopropionitrile (BPN) as initiator, 2, 2'-bipyridine (bipy) as ligand, and tisn(II) bis(2-ethylhexanoate) (Sn(EH)2) as reducing agent in the presence of air. With respect to AGET ATRP of AN catalyzed by CuBr2, an evident increase of polymer tacticity was observed for AGET ATRP of AN. The increase of syndiotacticity became more and more pronounced than the increase of isotacticity of polyacrylonitrile (PAN) along with YbBr3 content. The block copolymer PAN-b-PMMA with molecular weight at 60,000 and polydispersity at 1.36 was successfully prepared. PMID:24364980

  3. A STUDY ON MEMBRANE PROCESS WITH γ-ALUMINA MEMBRANE REACTOR FOR ETHYLBENZENE DEHYDROGENATION TO STYRENE

    Institute of Scientific and Technical Information of China (English)

    Chen Qingling; Xu Zhongqiang

    2001-01-01

    The membrane reaction of ethylbenzene(EB) dehydrogenation to styrene(ST) has been studied by using K2O/Fe2O3 industrial catalyst and γ-alumina ceramic membrane developed by our institute. In comparison with the packed bed reactor (that is, plug flow reactor, abbr. PFR) in industrial practice, the yield of styrene was increased by 5%~10% in the membrane reactor. Furthermore, mathematical modeling of membrane reaction has been studied to display the principle of optimal match between the catalytic activity and the membrane permeability.

  4. Toxicity of the styrene metabolite, phenylglyoxylic acid, in rats after three months' oral dosing

    DEFF Research Database (Denmark)

    Ladefoged, Ole; Lam, Henrik Rye; Ostergaard, G.;

    1998-01-01

    a functional observational battery or radial arm maze. An increased relative kidney weight was seen in the highest dose-group (Controls: 0.504 +/- 0.031 g/100 g b. wt.; 5000 mg PGA/I: 0.579 +/- 0.033 g/100 g b.wt.; pHistopathology revealed no change in kidney...... of the effects on kidney, peripheral nerves, and vision, which have previously been reported after exposure to styrene, might be induced by the styrene metabolite, PGA. If PGA has ototoxic effects in rats, the dosing in the present study is not sufficient to induce the necessary ototoxic concentration in blood...

  5. Coke formation in the oxidative dehydrogenation of ethylbenzene to styrene by TEOM

    OpenAIRE

    Nederlof, C.; P. Vijfhuizen; Zarubina, V.; Melián-Cabrera, I.; Kapteijn, F.; Makkee, M.

    2014-01-01

    A packed bed microbalance reactor setup (TEOM-GC) is used to investigate the formation of coke as a function of time-on-stream on γ-Al2O3 and 3P/SiO2 catalyst samples under different conditions for the ODH reaction of ethylbenzene to styrene. All samples show a linear correlation of the styrene selectivity and yield with the initial coverage of coke. The COX production increases with the coverage of coke. On the 3 wt% P/SiO2 sample, the initial coke build-up is slow and the coke deposition ra...

  6. GRAFTED STYRENE-DIVINYLBENZENE COPOLYMERS CONTAINING BENZALDEHYDES AND THEIR WITTIG REACTIONS WITH VARIOUS PHOSPHONIUM SALTS

    Institute of Scientific and Technical Information of China (English)

    Adriana Popa; Gheorghe Ilia; Aurelia Pascariu; Smaranda Iliescu; Nicoleta Plesu

    2005-01-01

    A chloromethylated styrene-divinylbenzene copolymer support system functionalized with 4-benzaldehyde and 2-benzaldehyde was prepared. The degree of functionalization with aldehyde groups is well suited for the subsequent use of the products as Wittig reagents. The polymer bound aldehyde was reacted with Wittig reagents to give olefin groups grafted on styrene-divinylbenzene copolymers. The reactions were carried out in phase transfer catalysis conditions. A simple procedure for the calculation of the degree of functionalization and the statistical modeling of the structural repetitive unit of the copolymer are reported.

  7. 0177 Exposure to styrene and the risk of cancer

    DEFF Research Database (Denmark)

    Christensen, Mette Skovgaard; Hansen, J; Ramlau-Hansen, Cecilia;

    2014-01-01

    OBJECTIVES: Styrene was incorporated in the 12(th) Report on Carcinogens (RoC) based on sufficient experimental evidence in animals. The human evidence has been evaluated as limited by RoC and IARC. The objective of this study was to analyse the risk of haematopoetic malignancies and other cancers...... following occupational styrene exposure. METHOD: The cohort consists of 74 902 workers (84% men) in the Danish reinforced plastics industry, originating from 481 companies ever producing reinforced plastics in Denmark 1964-2009. We identified all workers in the National Supplementary Pension Fund Registry...

  8. Azide-styrene resin negative deep UV resist for KrF excimer laser lithography

    International Nuclear Information System (INIS)

    The authors report a photosensitive composition, consisting of an aromatic azide compound (4,4'diazidodiphenyl methane) and a styrene resin (poly(styrene-co-maleic acid half-isoprapylate)), developed and evaluated as a negative deep ultra-violet (UV) resist for high-resolution KrF excimer laser lithography. Solubility of this resist in an aqueous developer decreases upon exposure to KrF excimer laser irradiation. The alkaline developer removes the unexposed areas of this resist. No swelling-induced pattern deformation occurs and high aspect ratio sub-half-micron patterns in 1.0 μm film thickness are obtained with high sensitivity

  9. Surface modification of poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) elastomer via covalent immobilization of nonionic sugar-based Gemini surfactants.

    Science.gov (United States)

    Xin, Zhirong; Du, Binbin; Yan, Shunjie; Du, Shanshan; Ding, Jiaotong; Yang, Zongfeng; Ren, Wanzhong

    2014-07-01

    Gemini surfactants (GS) with sugar-containing head-groups and different alkyl chains were successfully prepared. Poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) elastomer was grafted with glycidyl methacrylate (GMA) by means of UV-induced graft polymerization, and then the pGMA-grafted film was chemically immobilized with the GS. The surface graft polymerization was confirmed by ATR-FTIR and XPS. The wettability and hemocompatibility of the modified surface were characterized by means of water contact angle, protein adsorption, and platelet adhesion assays. The results showed that amphiphilic surfactant-containing polymer surfaces presented protein-resistant behavior and anti-platelet adhesion after functionalization with GS, GS1 and GS2. Besides, the hemocompatibility of the modified surface deteriorated as the length of hydrophobic chain of GS increased. PMID:24854325

  10. Surface modification of poly(styrene-b-(ethylene-co-butylene)-b-styrene) elastomer via UV-induced graft polymerization of N-vinyl pyrrolidone.

    Science.gov (United States)

    Luan, Shifang; Zhao, Jie; Yang, Huawei; Shi, Hengchong; Jin, Jing; Li, Xiaomeng; Liu, Jingchuan; Wang, Jianwei; Yin, Jinghua; Stagnaro, Paola

    2012-05-01

    Poly(N-vinyl pyrrolidone) (PNVP) was covalently grafted onto the surface of biomedical poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) elastomer via a technique of UV-induced graft polymerization combined with plasma pre-treatment. The surface graft polymerization of N-vinyl pyrrolidone (NVP) was confirmed by ATR-FTIR and XPS. Effect of the parameters of graft polymerization, i.e., the initiator concentration, the UV irradiation time and the monomer concentration on the grafting density was investigated. The morphology and the wettability of the PNVP-modified surfaces were characterized by AFM and DSA, respectively. Protein adsorption and platelet adhesion were obviously suppressed after PNVP was grafted onto the SEBS substrates. PMID:22264686

  11. Selective hydrogenation of 1,3-butadiene on platinum-copper alloys at the single-atom limit.

    Science.gov (United States)

    Lucci, Felicia R; Liu, Jilei; Marcinkowski, Matthew D; Yang, Ming; Allard, Lawrence F; Flytzani-Stephanopoulos, Maria; Sykes, E Charles H

    2015-01-01

    Platinum is ubiquitous in the production sectors of chemicals and fuels; however, its scarcity in nature and high price will limit future proliferation of platinum-catalysed reactions. One promising approach to conserve platinum involves understanding the smallest number of platinum atoms needed to catalyse a reaction, then designing catalysts with the minimal platinum ensembles. Here we design and test a new generation of platinum-copper nanoparticle catalysts for the selective hydrogenation of 1,3-butadiene,, an industrially important reaction. Isolated platinum atom geometries enable hydrogen activation and spillover but are incapable of C-C bond scission that leads to loss of selectivity and catalyst deactivation. γ-Alumina-supported single-atom alloy nanoparticle catalysts with <1 platinum atom per 100 copper atoms are found to exhibit high activity and selectivity for butadiene hydrogenation to butenes under mild conditions, demonstrating transferability from the model study to the catalytic reaction under practical conditions. PMID:26449766

  12. Dominant lethal study in CD-1 mice following inhalation exposure to 1,3-butadiene: Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Hackett, P.L.; Mast, T.J.; Brown, M.G.; Clark, M.L.; Evanoff, J.J.; Rowe, S.E.; McClanahan, B.J.; Buschbom, R.L.; Decker, J.R.; Rommereim, R.L.; Westerberg, R.B.

    1988-04-01

    The effects of whole-body inhalation exposures to 1,3-butadiene on the reproductive system was evaluated. The results of dominant lethality in CD-1 male mice that were exposed to 1,3-butadiene are described. Subsequent to exposure, males were mated with two unexposed females. Mating was continued for 8 weeks with replacement of two females each week. Gravid uteri were removed, and the total number, position and status of implantations were determined. The mice were weighed prior to exposure and at 0, 1, 2, 3, 4, 5, 6, 7, and 8 weeks after exposure and at sacrifice. The animals were observed for mortality, morbidity and signs of toxicity throughout the study. 19 refs., 5 figs., 9 tabs.

  13. Experimental study of the structure of rich premixed 1,3-butadiene/CH4/O2/Ar flame

    CERN Document Server

    Gueniche, Hadj-Ali; Fournet, René; Battin-Leclerc, Frédérique

    2006-01-01

    The structure of a laminar rich premixed 1,3-C4H6/CH4/O2/Ar flame have been investigated. 1,3-Butadiene, methane, oxygen and argon mole fractions are 0.033; 0.2073; 0.3315, and 0.4280, respectively, for an equivalent ratio of 1.80. The flame has been stabilized on a burner at a pressure of 6.7 kPa (50 Torr). The concentration profiles of stable species were measured by gas chromatography after sampling with a quartz probe. Quantified species included carbon monoxide and dioxide, methane, oxygen, hydrogen, ethane, ethylene, acetylene, propyne, allene, propene, cyclopropane, 1,3-butadiene, butenes, 1-butyne, vinylacetylene, diacetylene, C5 compounds, benzene, and toluene. The temperature was measured thanks to a thermocouple in PtRh (6%)-PtRh (30%) settled inside the enclosure and ranged from 900 K close to the burner up to 2100 K.

  14. Theoretical and experimental investigations of the 2-(4-chlorophenyl)-3-{[5-(2-cyano-2-phenylethenyl)]furan-2-yl}acrylonitrile molecule as a potential acceptor in organic solar cells

    Science.gov (United States)

    Kazici, Mehmet; Bozar, Sinem; Aydin Yuksel, Sureyya; Ongul, Fatih; Gokce, Halil; Gunes, Serap; Yorur Goreci, Cigdem

    2016-06-01

    A novel soluble asymmetric acrylonitrile derivative, 2-(4-Chlorophenyl)-3-{[5-(2-cyano-2-phenylethenyl)]furan-2-yl}acrylonitrile (CPCPFA, 3) was synthesized in three steps by Knoevenagel condensation. The structure of the CPCPFA was characterized using UV-vis, FTIR, 1H NMR, 13C NMR, and LC-MS. CPCPFA was evaluated as an electron acceptor in bulk heterojunction organic solar cells. Its optical and electronic properties as well as photovoltaic performance were investigated.

  15. Atmospheric oxidation of isoprene and 1,3-butadiene: influence of aerosol acidity and relative humidity on secondary organic aerosol

    Directory of Open Access Journals (Sweden)

    M. Lewandowski

    2014-11-01

    Full Text Available The effects of acidic seed aerosols on the formation of secondary organic aerosol (SOA have been examined in a number of previous studies, several of which have observed strong linear correlations between the aerosol acidity (measured as nmol H+ per m3 air sample volume and the percent change of secondary organic carbon (SOC. The measurements have used several precursor compounds representative of different classes of biogenic hydrocarbons including isoprene, monoterpenes, and sesquiterpenes. To date, isoprene has displayed the most pronounced increase in SOC, although few measurements have been conducted with anthropogenic hydrocarbons. In the present study, we examine several aspects of the effect of aerosol acidity on the secondary organic carbon formation from the photooxidation of 1,3-butadiene, as well as extending the previous analysis of isoprene. The photooxidation products measured in the absence and presence of acidic sulfate aerosols were generated either through photochemical oxidation of SO2 or by nebulizing mixtures of ammonium sulfate and sulfuric acid into a 14.5 m3 smog chamber system. The results showed that, like isoprene and β-caryophyllene, 1,3-butadiene SOC yields linearly correlate with increasing acidic sulfate aerosol. The observed acid sensitivity of 0.11% SOC increase per nmol m−3 increase in H+ was approximately a factor of three less than that measured for isoprene. The results also showed that the aerosol yield decreased with increasing humidity for both isoprene and 1,3-butadiene, although to different degrees. Increasing the absolute humidity from 2 to 12 g m−3 reduced the 1,3-butadiene yield by 45% and the isoprene yield by 85%.

  16. VAPOR-PHASE CATALYTIC CONVERSION OF ETHANOL INTO 1,3-BUTADIENE ON Cr-Ba/MCM-41 CATALYSTS

    Directory of Open Access Journals (Sweden)

    N. La-Salvia

    2015-06-01

    Full Text Available AbstractAl-MCM-41, 16%Ba/Al-MCM-41 and 1.4%Cr-16%Ba/Al-MCM-41 were used as catalysts in the vapor-phase catalytic conversion of ethanol. Physical-chemical properties of the catalysts and the effect of barium and chromium on the Al-MCM-41 activity and 1,3-butadiene yield were studied. The catalysts were characterized by X-ray diffraction (XRD, N2 physisorption (BET method, CO2chemisorption and Fourier transform infrared spectroscopy (FT-IR. When ethanol was completely converted on Al-MCM-41 and 16%Ba/Al-MCM-41, the reaction products showed a high selectivity for ethylene (90-98%. However, on the 1.4%Cr-16%Ba/Al-MCM-41 catalyst, a greater number of reaction products were obtained such as ethylene, acetaldehyde, diethyl ether and 1,3-butadiene. The maximum 1,3-butadiene yield obtained from ethanol reaction was 25% at 723 K and W/FEtOH = 15 g h mol-1. The latter result was obtained in a single step and without addition of reaction promoters (e.g., acetaldehyde, crotonaldehyde, hydrogen in the feed stream to the reactor.

  17. High-Temperature Measurements and a Theoretical Study of the Reaction of OH with 1,3-Butadiene

    Energy Technology Data Exchange (ETDEWEB)

    Vasu, Subith [Stanford Univ., CA (United States); Zador, J. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Davidson, David F. [Stanford Univ., CA (United States); Hanson, Ronald K. [Stanford Univ., CA (United States); Golden, David [Stanford Univ., CA (United States); Miller, James A. [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2010-07-27

    The reaction of hydroxyl (OH) radicals with 1,3-butadiene (C4H6) was studied behind reflected shock waves over the temperature range 1011-1406 K and at pressures near 2.2 atm. OH radicals were produced by shock-heating tert-butyl hydroperoxide, (CH3)3-CO-OH, and were monitored by narrow line width ring dye laser absorption of the well-characterized R1(5) line of the OH A-X (0,0) band near 306.7 nm. OH time histories were modeled using a comprehensive 1,3-butadiene oxidation mechanism, and rate constants for the reaction of OH with 1,3-butadiene were extracted by matching modeled and measured OH concentration time histories. Detailed error analyses yielded an uncertainty estimate of ±13% at 1200 K for the rate coefficient of the target reaction. The current data extends the temperature range of the only previous high-temperature study for this reaction. The rate coefficient and the branching fractions for the H-abstraction channels of the target reaction were also calculated over the temperature range 250-2500 K using variational transition-state theory based on QCISD(T)/cc-pV∞Z//B3LYP/6-311++G(d,p) quantum chemistry. The calculations are in good agreement with the experimental results above 1200 K.

  18. Delayed light emission of Tetraphenyl-butadiene excited by liquid argon scintillation light. Current status and future plans

    Science.gov (United States)

    Segreto, E.; Machado, A. A.; Araujo, W.; Teixeira, V.

    2016-02-01

    Tetraphenyl-butadiene is the wavelength shifter most widely used in combination with liquid argon. The latter emits scintillation photons with a wavelength of 127 nm that need to be downshifted to be detected by photomultipliers with glass or quartz windows. Tetraphenyl-butadiene has been demonstrated to have an extremely high conversion efficiency, possibly higher than 100% for 127 nm photons, while there is no precise information about the time dependence of its emission. It is usually assumed to be exponentially decaying with a characteristic time of the order of one ns, as an extrapolation from measurements with exciting radiation in the near UV . This work shows that tetraphenyl-butadiene, when excited by 127 nm photons, re-emits photons not only with a very short decay time, but also with slower ones due to triplet states de-excitations. This fact can strongly contribute to clarifying the anomalies in liquid-argon scintillation light reported in the literature since the 1970s. Precision measurements of the properties of TPB, when excited by Vacuum Ultra Violet photons are being carried on at the Brazilian Synchrotron Light Laboratory in Campinas (State of São Paulo).

  19. Cyclodimerization of Stilbenes and Styrenes Catalyzed by Heteropolyacid Supported on Silica

    Directory of Open Access Journals (Sweden)

    B. Lantaño

    2000-03-01

    Full Text Available Several stilbenes and styrenes have been treated with heteropolyacid] (HPA supported over silice. The compounds obtained were characterized by 1H and 13C- NMR and the yields were compared with those obtained using H2SO4 (c and ethyl poliphosphate] (PPE.

  20. Facile synthesis of carbon nanotube/natural bentonite composites as a stable catalyst for styrene synthesis.

    Science.gov (United States)

    Rinaldi, Ali; Zhang, Jian; Mizera, Jan; Girgsdies, Frank; Wang, Ning; Hamid, Sharifah Bee Abd; Schlögl, Robert; Su, Dang Sheng

    2008-12-28

    Natural bentonite mineral, without any wet chemical treatment, was used directly to catalyze the growth of multi-wall CNTs and the produced CNTs/bentonite as an integrated composite stably catalyzed the oxidative dehydrogenation reaction over a long period of time; this concept provides a highly economical way for large-scale synthesis of nanocarbons and manufacture of styrene synthesis catalysts. PMID:19057768

  1. EVALUATION OF THE POLYAD FB AIR PURIFICATION AND SOLVENT RECOVERY PROCESS FOR STYRENE REMOVAL

    Science.gov (United States)

    The report gives results of a study evaluating the Polyad fluidized-bed (FB) process for controlling styrene emissions at a representative fiberglass shower stall and bath tub manufacturing plan*t. he process was evaluated using a transport able unit supplied by Weatherly, Inc., ...

  2. Free radical suspension polymerization kinetics of styrene up to high conversion

    NARCIS (Netherlands)

    Tefera, Nurelegne; Weickert, Günter; Bloodworth, Robert; Schweer, Johannes

    1994-01-01

    Styrene was polymerized using different amounts of azoisobutyronitrile as initiator at temperatures of 70°C, 75°C and 80°C in suspension. The course of reaction up to almost complete conversion was modeled within a classical kinetic framework. Optimal simultaneous descriptions of both conversion and

  3. 78 FR 20032 - Styrene-Ethylene-Propylene Block Copolymer; Tolerance Exemption

    Science.gov (United States)

    2013-04-03

    .... No. 108388-87-0) when used as an inert ingredient in a pesticide formulation. AgroFresh Inc... permissible level for residues of styrene-ethylene-propylene block copolymer on food or feed commodities... code 111). Animal production (NAICS code 112). Food manufacturing (NAICS code 311)....

  4. 76 FR 77709 - Butyl acrylate-methacrylic acid-styrene polymer; Tolerance Exemption

    Science.gov (United States)

    2011-12-14

    ...-styrene polymer when used as an inert ingredient in a pesticide chemical formulation. Momentive...-propenoate and ethenylbenzene on food or feed commodities. DATES: This regulation is effective December 14...: Crop production (NAICS code 111). Animal production (NAICS code 112). Food manufacturing (NAICS...

  5. Styrene Production Technology%苯乙烯生产技术[1~6

    Institute of Scientific and Technical Information of China (English)

    蔡丽娟

    2001-01-01

    In this paper,the world-wide production technology of styrene is analyzed,and its domestic technologic development is proposed.%本文分析了苯乙烯技术的发展前景,提出我国苯乙烯技术发展的意义和建议。

  6. A Novel Metal-free and Highly Efficient Hydroarylation of Styrenes Catalyzed by Molecular Iodine

    Institute of Scientific and Technical Information of China (English)

    SUN Gao-Jun; ZHANG Tai-Chang; SHENG Liu-Si; QI Fei; WANG Zhi-Yong

    2008-01-01

    A molecular iodine catalyzed hydroarylation of styrenes by arenes has been developed.This reaction could be carried out at 25 ℃ under a solvent-free condition, giving rise to the corresponding products with yields up to 93%.A series of 1,1-diarylalkane derivatives were easily prepared without any involvement of metal catalysts.

  7. Development of Styrene-Grafted Polyurethane by Radiation-Based Techniques

    Directory of Open Access Journals (Sweden)

    Jin-Oh Jeong

    2016-06-01

    Full Text Available Polyurethane (PU is the fifth most common polymer in the general consumer market, following Polypropylene (PP, Polyethylene (PE, Polyvinyl chloride (PVC, and Polystyrene (PS, and the most common polymer for thermosetting resins. In particular, polyurethane has excellent hardness and heat resistance, is a widely used material for electronic products and automotive parts, and can be used to create products of various physical properties, including rigid and flexible foams, films, and fibers. However, the use of polar polymer polyurethane as an impact modifier of non-polar polymers is limited due to poor combustion resistance and impact resistance. In this study, we used gamma irradiation at 25 and 50 kGy to introduce the styrene of hydrophobic monomer on the polyurethane as an impact modifier of the non-polar polymer. To verify grafted styrene, we confirmed the phenyl group of styrene at 690 cm−1 by Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR and at 6.4–6.8 ppm by 1H-Nuclear Magnetic Resonance (1H-NMR. Scanning Electron Microscope (SEM, X-ray Photoelectron Spectroscopy (XPS, Thermogravimetric Analysis (TGA and contact angle analysis were also used to confirm styrene introduction. This study has confirmed the possibility of applying high-functional composite through radiation-based techniques.

  8. Surface Treatment of Fibre Boards with Mixtures of Unsaturated Polyesters in Styrene

    International Nuclear Information System (INIS)

    Results of a research project for the development of construction boards provided with a coating of unsaturated polyesters and styrene are reported. Peroxide curing was compared with electron curing by a linear accelerator. Results of weather tests after 3 to 8 months in natural weather conditions are reported. (author)

  9. Global styrene oligomers monitoring as new chemical contamination from polystyrene plastic marine pollution.

    Science.gov (United States)

    Kwon, Bum Gun; Koizumi, Koshiro; Chung, Seon-Yong; Kodera, Yoichi; Kim, Jong-Oh; Saido, Katsuhiko

    2015-12-30

    Polystyrene (PS) plastic marine pollution is an environmental concern. However, a reliable and objective assessment of the scope of this problem, which can lead to persistent organic contaminants, has yet to be performed. Here, we show that anthropogenic styrene oligomers (SOs), a possible indicator of PS pollution in the ocean, are found globally at concentrations that are higher than those expected based on the stability of PS. SOs appear to persist to varying degrees in the seawater and sand samples collected from beaches around the world. The most persistent forms are styrene monomer, styrene dimer, and styrene trimer. Sand samples from beaches, which are commonly recreation sites, are particularly polluted with these high SOs concentrations. This finding is of interest from both scientific and public perspectives because SOs may pose potential long-term risks to the environment in combination with other endocrine disrupting chemicals. From SOs monitoring results, this study proposes a flow diagram for SOs leaching from PS cycle. Using this flow diagram, we conclude that SOs are global contaminants in sandy beaches around the world due to their broad spatial distribution. PMID:26218303

  10. Highly efficient and selective pressure-assisted photon-induced polymerization of styrene

    Science.gov (United States)

    Guan, Jiwen; Song, Yang

    2016-06-01

    The polymerization process of condensed styrene to produce polystyrene as an industrially important polymeric material was investigated using a novel approach by combining external compression with ultraviolet radiation. The reaction evolution was monitored as a function of time and the reaction products were characterized by in situ Fourier transform infrared spectroscopy. By optimizing the loading pressures, we observed highly efficient and selective production of polystyrene of different tacticities. Specifically, at relatively low loading pressures, infrared spectra suggest that styrene monomers transform to amorphous atactic polystyrene (APS) with minor crystalline isotactic polystyrene. In contrast, APS was found to be the sole product when polymerization occurs at relatively higher loading pressures. The time-dependent reaction profiles allow the examination of the polymerization kinetics by analyzing the rate constant and activation volume as a function of pressure. As a result, an optimized pressure condition, which allows a barrierless reaction to proceed, was identified and attributed to the very desirable reaction yield and kinetics. Finally, the photoinitiated reaction mechanism and the growth geometry of the polymer chains were investigated from the energy diagram of styrene and by the topology analysis of the crystal styrene. This study shows strong promise to produce functional polymeric materials in a highly efficient and controlled manner.

  11. Swelling of organoclays in styrene. Effect on flammability in polystyrene nanocomposites

    Directory of Open Access Journals (Sweden)

    2010-08-01

    Full Text Available In this work the effect of the compatibility between organoclays and styrene on the flammability of polystyrene/clay nanocomposites obtained through in situ incorporation was investigated. The reactions were carried out by bulk polymerization. The compatibility between organoclays and styrene was inferred from swelling of the organoclay in styrene. The nanocomposites were characterized by X-ray diffraction and Transmission Electron Microscopy. The heat release rate was obtained by Cone Calorimeter and the nanocomposites were tested by UL94 horizontal burn test. Results showed that intercalated and partially exfoliated polystyrene/clay nanocomposites were obtained depending on the swelling behavior of the organoclay in styrene. The nanocomposites submitted to UL94 burning test presented a burning rate faster than the virgin polystyrene (PS, however an increase of the decomposition temperature and an accentuated decrease on the peak of heat release of the nanocomposites were also observed compared to virgin PS. These results indicate that PS/clay nanocomposites, either intercalated or partially exfoliated, reduced the flammability approximately by the same extent, although reduced the ignition resistance of the PS.

  12. Synthesis and characterization of Cr-MSU-1 and its catalytic application for oxidation of styrene

    Science.gov (United States)

    Liu, Hong; Wang, Zhigang; Hu, Hongjiu; Liang, Yuguang; Wang, Mengyang

    2009-07-01

    Chromium-containing mesoporous silica material Cr-MSU-1 was synthesized using lauryl alcohol-polyoxyethylene (23) ether as templating agent under the neutral pH condition by two-step method. The sample was characterized by XRD, TEM, FT-IR, UV-Vis, ESR, ICP-AES and N 2 adsorption. Its catalytic performance for oxidation of styrene was studied. Effects of the solvent used, the styrene/H 2O 2 mole ratio and the reaction temperature and time on the oxidation of styrene over the Cr-MSU-1 catalyst were examined. The results indicate that Cr ions have been successfully incorporated into the framework of MSU-1 and the Cr-MSU-1 material has a uniform worm-like holes mesoporous structure. After Cr-MSU-1 is calcined, most of Cr 3+ is oxidized to Cr 5+ and Cr 6+ in tetrahedral coordination and no extra-framework Cr 2O 3 is formed. The Cr-MSU-1 catalyst is highly active for the selective oxidation of styrene and the main reaction products over Cr-MSU-1 are benzaldehyde and phenylacetaldehyde. Its catalytic performance remains stable within five repeated runs and no leaching is noticed for this chromium-based catalyst.

  13. Styrene induces an inflammatory response in human lung epithelial cells via oxidative stress and NF-κB activation

    International Nuclear Information System (INIS)

    Styrene is a volatile organic compound (VOC) that is widely used as a solvent in many industrial settings. Chronic exposure to styrene can result in irritation of the mucosa of the upper respiratory tract. Contact of styrene with epithelial cells stimulates the expression of a variety of inflammatory mediators, including the chemotactic cytokine monocyte chemoattractant protein-1 (MCP-1). To characterise the underlying mechanisms of the induction of inflammatory signals by styrene, we investigated the influence of this compound on the induction of oxidative stress and the activation of the nuclear factor-kappa B (NF-κB) signalling pathway in human lung epithelial cells (A549). The results demonstrate that styrene-induced MCP-1 expression, as well as the expression of the oxidative stress marker glutathione S-transferase (GST), is associated with a concentration dependent pattern of NF-κB activity. An inhibitor of NF-κB, IKK-NBD, and the anti-inflammatory antioxidant N-acetylcysteine (NAC) were both effective in suppressing styrene-induced MCP-1 secretion. In addition, NAC was capable of inhibiting the upregulation of GST expression. Our findings suggest that the activation of the NF-κB signalling pathway by styrene is mediated via a redox-sensitive mechanism

  14. Heterogeneous catalytic oxidative dehydrogenation of ethylbenzene to styrene with carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Badstube, T.; Papp, H. [Leipzig Univ. (Germany). Inst. fuer Technische Chemie; Kustrowski, P.; Dziembaj, R. [Jagiellonian Univ., Crakow (Poland). Faculty of Chemistry

    1998-12-31

    Alkaline promoted active carbon supported iron catalysts are very active in the oxidative dehydrogenation of ethylbenzene to styrene in the presence of carbon dioxide. The best results were obtained at 550 C for a Li-promoted catalyst with a conversion of ethylbenzene of 75% and a selectivity towards styrene of nearly 95%. These results are better than those obtained with industrial catalysts which perform the dehydrogenation process with an excess of water. The main product of the dehydrogenation reaction with CO{sub 2} was styrene, but the following by-products were detected - benzene and toluene. The selectivity towards toluene was always higher than towards benzene. We observed also the formation of carbon monoxide and water, which were produced with a constant molar ratio of about 0.8. The weight of the catalysts increased up to 20% during the reaction due to deposition of carbon. Using a too large excess of CO{sub 2} (CO{sub 2}/EB>10) was harmful for the styrene yield. The most favorable molar ratio of CO{sub 2} to EB was 10:1. No correlation between the molar ratios of reactants and the amount of deposited coke on the surface of catalysts was observed. The highest catalytic activity showed iron loaded D-90 catalysts which were promoted with alkali metals in a molar ratio of 1:10. Iron, nickel and cobalt loaded carbonized PPAN, PC, inorganic supports like Al{sub 2}O{sub 3}, SiO{sub 2}/ZrO{sub 2} or TiO{sub 2} respectively and commercial iron catalysts applied for styrene production did not show comparable catalytic activity in similar conditions. (orig.)

  15. The Protective Effects of Gadolinum Chloride on Pneumotoxic Effects of Styrene in Rat

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Arab

    2015-07-01

    Full Text Available Objective: The aim of the present study was to evaluate the protective effects of gadolinum on pneumotoxic effects of styrene in rats as an experimental model. Materials and Methods: In this experimental study a total number of 40 adult male Sprague Dawley rats that weighed 200 ± 13 g were randomly divided into five groups: i. styrene (St, N=10, ii. styrene+gadolinium chloride (GdCl3, N=10, iii. control (N=10, iv. GdCl3 (N=5 and v. normal saline (Nor.Sal, as a solvent of GdCl3, N=5. Normal saline, as a sham control group, was otherwise treated identically. Rats from the experimental groups were exposed to St in an exposure chamber for 6 days/week, 4 hours/day for up to 3 weeks. At the end of the experiment, rats from all groups were killed by deep anesthesia. Their lungs were removed, then fixed in formalin and weighed. Tissue samples were processed routinely and sections stained by the hematoxylin and eosin (H&E and periodic acid Schiff (PAS methods. We measured the thicknesses of the respiratory epithelia and interalveolar septa. Obtained data were analyzed by ANOVA, the Tukey test and the paired t test. Results: Shedding of apical cytoplasm in the bronchiole was a prominent feature of the St group. PAS staining revealed histochemical changes in goblet cells in the epithelium of the St group. While there were no significant changes in lung weights and respiratory epithelial thicknesses between all studied groups, statistical analysis showed a significant alteration in the thickness of interalveolar septa in the St and St+GdCl3 group compared to the control groups (P<0.001. Conclusion: Styrene induced structural and histochemical changes in bronchiole, interalveolar septa and alveolar organization in the rats’ lungs. Gadolinium appeared to partially reduce the toxic effects of styrene on the lungs.

  16. 丙烯腈生殖毒理学研究概况%An Overview of the Study of Acrylonitrile on Reproductive Toxiocology

    Institute of Scientific and Technical Information of China (English)

    吴鑫; 金泰; 钟先玖

    2000-01-01

    @@ 丙烯腈(acrylonitrile,ACN)为有机合成工业中广泛应用的一种重要单体物质,可合成腈纶纤维,丁腈橡胶,ABS工程塑料及某些树脂.1994年全世界的ACN生产量超过30亿磅,1995年已达到100亿磅的生产能力[1].

  17. The emissions of monoaromatic hydrocarbons from small polymeric toys placed in chocolate food products.

    Science.gov (United States)

    Marć, Mariusz; Formela, Krzysztof; Klein, Marek; Namieśnik, Jacek; Zabiegała, Bożena

    2015-10-15

    The article presents findings on the emissions of selected monoaromatic hydrocarbons from children's toys placed in chocolate food products. The emission test system involved the application of a new type of microscale stationary emission chamber, μ-CTE™ 250. In order to determine the type of the applied polymer in the manufacture of the tested toys, Fourier transform infrared spectroscopy and thermogravimetric analysis coupled with differential scanning calorimetry were used. It was found that the tested toy components or the whole toys (figurines) are made of two main types of polymers: polyamide and acrylonitrile-butadiene-styrene copolymer. Total number of studied small polymeric toys was 52. The average emissions of selected monoaromatic hydrocarbons from studied toys made of polyamide were as follows: benzene: 0.45 ± 0.33 ng/g; toluene: 3.3 ± 2.6 ng/g; ethylbenzene: 1.4 ± 1.4 ng/g; p,m-xylene: 2.5 ± 4.5 ng/g; and styrene: 8.2 ± 9.9 ng/g. In the case of studied toys made of acrylonitrile-butadiene-styrene copolymer the average emissions of benzene, toluene, ethylbeznene, p,m-xylene and styrene were: 0.31 ± 0.29 ng/g; 2.5 ± 1.4 ng/g; 4.6 ± 8.9 ng/g; 1.4 ± 1.1 ng/g; and 36 ± 44 ng/g, respectively.

  18. Characterization of hepatocellular resistance and susceptibility to styrene toxicity in B6C3F1 mice.

    Science.gov (United States)

    Mahler, J F; Price, H C; O'Connor, R W; Wilson, R F; Eldridge, S R; Moorman, M P; Morgan, D L

    1999-03-01

    Short-term inhalation exposure of B6C3F1 mice to styrene causes necrosis of centrilobular (CL) hepatocytes. However, in spite of continued exposure, the necrotic parenchyma is rapidly regenerated, indicating resistance by regenerated cells to styrene toxicity. These studies were conducted to test the hypothesis that resistance to repeated styrene exposure is due to sustained cell proliferation, with production of hepatocytes that have reduced metabolic capacity. Male mice were exposed to air or 500 ppm styrene (6 h/day); hepatotoxicity was evaluated by microscopic examination, serum liver enzyme levels, and bromodeoxyuridine (BrdU)-labeling index (LI). Metabolism was assessed by measurement of blood styrene and styrene oxide. Both single and repeated exposures to styrene resulted in mortality by Day 2; in mice that survived, there was CL necrosis with elevated BrdU LI at Day 6, and complete restoration of the necrotic parenchyma by Day 15. The BrdU LI in mice given a single exposure had returned to control levels by Day 15. Re-exposure of these mice on Day 15 resulted in additional mortality and hepatocellular necrosis, indicating that regenerated CL cells were again susceptible to the cytolethal effect of styrene following a 14-day recovery. However, in mice repeatedly exposed to styrene for 14 days, the BrdU LI remained significantly increased on Day 15, with preferential labeling of CL hepatocytes with enlarged nuclei (karyomegaly). If repeated exposures were followed by a 10-day recovery period, CL karyomegaly persisted, but the BrdU LI returned to control level and CL hepatocytes became susceptible again to styrene toxicity as demonstrated by additional mortality and acute necrosis after a challenge exposure. These findings indicated a requirement for continued styrene exposure and DNA synthesis in order to maintain this resistant phenotype. Analyses of proliferating-cell nuclear-antigen (PCNA) labeling were conducted to further characterize the cell cycle

  19. Synthesis of Cyclododecatriene from 1,3-Butadiene by Trimerization over Amine-Titanium Complex Catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Park, Da Min; Kim, Gye Ryung; Lee, Ju Hyun; Kim, Geon-Joong [Inha University, Incheon (Korea, Republic of); Cho, Deuk Hee [Korea Research Institute of Chemical Technology, Daejeon (Korea, Republic of)

    2013-06-15

    The new complex catalysts were synthesized by the reaction of titanium compounds (titanium chloride or titanium butoxide) and diamines in this work, and they showed very high catalytic activities for the cyclododecatriene (CDT) synthesis from 1,3-butadiene through trimerization. CDT synthetic reaction was performed in an autoclave reactor, and the effects of reaction temperature, type of catalyst, catalyst amount added into the system, the mole ratio of Al/Ti and immobilization method were investigated on the yield of product CDT. The titanium complex catalyst combined to diamine with 1:1 ratio showed high selectivity to CDT more than 90%. The ratio of TTT-CDT/TTC-CDT isomers in the product revealed as different values, depending on the type of diamine combined to titanium and Ti/diamine ratios. Those homogeneous complexes could be used as a heterogenized catalyst after anchoring on the supports, and the immobilized titanium catalyst retained the catalytic activities for several times in the recycled reactions without leaching. The carbon support containing titanium has exhibited superior activity to the silica support. Especially, when the titanium complex was anchored on the support which was fabricated by the hydrolysis of tripropylaminosilane itself, the resulting titanium catalyst showed the highest BD conversion and CDT selectivity.

  20. SYNTHESIS AND PHARMACOLOGICAL EFFECTS OF BUTADIENE AND CYCLOPENTADIENE ADDUCTS OF METHANDROSTENOLONE IN RATS

    Directory of Open Access Journals (Sweden)

    FAZEL SHAMSA

    2006-06-01

    Full Text Available In this study the reactivity of methandrostenolone or [(17b-17-hydroxy-17-methylandrosta-1, 4-diene-3-one], as a dienophil in a Diels-Alder type cycloaddition reaction was investigated. The purpose of this approach was to investigate whether the 1-dehydro position of methandrostenolone 1 undergoes a cycloaddition reaction with dienes, such as 1, 3 butadiene or cyclopentadiene, and to investigate the biological behavior of the reaction adducts, i.e, compound 3 {(17b-17-hydroxy-17-methyl androsta [1a, 2a] cyclohex 3’, 4-diene-3-one} and compound 4 {(17b-17-hydroxy-17-methyl androsta [1a, 2a] cyclohex (2’,5’ methylene 3’, 4-diene-3-one}, relative to compound 1. The results indicated that thedDiels-Alder reactionddid notpproceed under the usual circumstances of high pressure and temperature, but could proceed in the presence of a Lewis acid (AlCl3. The structures of compounds 3 and 4 were confirmed by spectroscopic methods. The androgenic behavior of compounds 3 and 4 in comparison to compound 1 in the apomorphine test indicated that both compounds were almost devoid of androgenic activity, but prevented apomorphine mediated penile erection in male rats in a similar manner as cyproterone acetate.

  1. Degradation of Hydrogenated Nitrile-butadiene Rubber in Aqueous Solutions of H2S or HCl

    Institute of Scientific and Technical Information of China (English)

    CONG Chuan-bo; CUI Can-can; MENG Xiao-yu; LU Shao-jie; ZHOU Qiong

    2013-01-01

    The degradation of hydrogenated nitrile-butadiene rubber(HNBR) soaped in aqueous solutions of H2S and HCl was investigated.The samples unexposed and exposed to different solutions were characterized by 13C nuclear magnetic resonance(13C NMR),X-ray photoelectron and infrared spectroscopies.In contrast to those of unexposed samples and samples soaped in HCl solution,the mechanical properties of samples exposed to H2S solution significantly deteriorated,in which the new groups of C(=O)-NH2,C-S-C and C=S emerged.The mechanism of C=S and C-S-C formation was speculated,except for that of the formation of group C(=O)-NH2,which was widely discussed in acidic condition such as HC1 solution.The formation of C-S-C was due to radical reaction initiated by mercapto radical and that of C=S was due to nucleophilic reaction initiated by mercapto cations.This finding is helpful to understanding the seal failure of HNBR in working environment containing H2S.

  2. Biological monitoring to determine worker dose in a butadiene processing plant

    Energy Technology Data Exchange (ETDEWEB)

    Bechtold, W.E.; Hayes, R.B. [National Cancer Inst., Bethesda, MD (United States)

    1995-12-01

    Butadiene (BD) is a reactive gas used extensively in the rubber industry and is also found in combustion products. Although BD is genotoxic and acts as an animal carcinogen, the evidence for carcinogenicity in humans is limited. Extrapolation from animal studies on BD carcinogenicity to risk in humans has been controversial because of uncertainties regarding relative biologic exposure and related effects in humans vs. experimental animals. To reduce this uncertainty, a study was designed to characterize exposure to BD at a polymer production facility and to relate this exposure to mutational and cytogenetic effects. Biological monitoring was used to better assess the internal dose of BD received by the workers. Measurement of 1,2-dihydroxy-4-(N-acetylcysteinyl) butane (M1) in urine served as the biomarker in this study. M1 has been shown to correlate with area monitoring in previous studies. Most studies that relate exposure to a toxic chemical with its biological effects rely on exposure concentration as the dose metric; however, exposure concentration may or may not reflect the actual internal dose of the chemical.

  3. Synthesis of DNA Oligodeoxynucleotides Containing Site-Specific 1,3-Butadiene- Deoxyadenosine Lesions

    Science.gov (United States)

    Wickramaratne, Susith; Seiler, Christopher L.

    2016-01-01

    Post-oligomerization synthesis is a useful technique for preparing site-specifically modified DNA oligomers. This approach involves site-specific incorporation of inherently reactive halogenated nucleobases into DNA strands using standard solid phase synthesis, followed by post-oligomerization nucleophilic aromatic substitution (SNAr) reactions with carcinogen-derived synthons. In these reactions, the inherent reactivities of DNA and carcinogen-derived species are reversed: the modified DNA nucleobase acts as an electrophile, while the carcinogen-derived species acts as a nucleophile. In the present protocol, we describe the use of the post-oligomerization approach to prepare DNA strands containing site- and stereospecific N6-adenine and N1, N6-adenine adducts induced by epoxide metabolites of the known human and animal carcinogen, 1,3-butadiene (BD). The resulting oligomers containing site specific, structurally defined DNA adducts can be used in structural and biological studies to reveal the roles of specific BD adducts in carcinogenesis and mutagenesis. PMID:26344227

  4. FRACTAL CHARACTER OF PHASE MORPHOLOGY OF HIGH IMPACT POLYSTYRENE/POLY(cis-BUTADIENE) RUBBER BLENDS

    Institute of Scientific and Technical Information of China (English)

    Yun-yan Li; Yun-ping Han; Jing Sheng

    2006-01-01

    Evolution and fractal character of the phase morphology of high impact polystyrene/poly(cis-butadiene) rubber (HIPS/PcBR) blends during melting and mixing were investigated using scanning electron microscopy (SEM). The characteristic length L was defined as the size of particles of the dispersed phase in blends. Different fractal dimensions, Df and Dm, were introduced to study the distribution width of phase dimensions in the dimensionless region and the uniformity of the spatial distribution of particles, respectively. The results showed that the average characteristic length Lm and Df increase as the volume fraction of the dispersed phase increases, when the volume fraction of the dispersed phase is lower than 50%. In other words, the size of particles increases and their distribution in the dimensionless region becomes more uniform. Meanwhile, the uniformity of the spatial distribution becomes more perfect as the volume fraction increases. At a certain composition, Lm decreases in the initial stage of the mixing and levels off in the late stage. In the initial stage, Df becomes large rapidly with the process of blending, which means that the distribution of L in the dimensionless region becomes more uniform. Meanwhile, the spatial distribution tends to be ideal rapidly in the early stage and fluctuates in a definite range in the late stage of the mixing.

  5. Viscoelastic properties of hydroxyl-terminated poly(butadiene based composite rocket propellants

    Directory of Open Access Journals (Sweden)

    Brzić Saša J.

    2014-01-01

    Full Text Available In the present study, the viscoelastic response of three composite solid propellants based on hydroxyl-terminated poly(butadiene, ammonium perchlorate and aluminum has been investigated. The investigation was surveyed by dynamic mechanical analysis over a wide range of temperatures and frequencies. The mechanical properties of these materials are related to the macromolecular structure of the binder as well as to the content and nature of solid fillers. The storage modulus, loss modulus, loss factor and glass transition temperature for each propellant sample have been evaluated. The master curves of storage (log G' vs log ω and loss modulus (log G'' vs log ω were generated for each propellant. A comparison of logaT vs temperature curves for all propellants indicate conformance to Williams-Landel-Ferry equation. Choosing the glass transition as the reference temperature, WLF equation constants are determined. Fractional free volume at the glass transition temperature and thermal coefficient of free volume expansion values are in accordance with the consideration that Al is reinforcing filler.

  6. Effect of water on hydrogenation of 1,3-butadiene over Au (1 1 1): A joint theoretical and experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Bu, Weida; Zhao, Liang, E-mail: Liangzhao@cup.edu.cn; Zhang, Zhicheng; Zhang, Xin; Gao, Jinsen; Xu, Chunming

    2014-01-15

    The effect of water on the hydrogenation of 1,3-butadiene over Au (1 1 1) was investigated based on density functional theory calculations and the results were compared with experimental study on the same reaction over Au/γ-Al{sub 2}O{sub 3} catalysts prepared by different methods. All possible adsorption sites and geometry structures of hydrogen, water and 1,3-butadiene on Au (1 1 1) were considered in the adsorption energy calculations to obtain the optimized adsorption modes. The hydrogenation of 1,3-butadiene was found to be only feasible with dissociated H atoms adsorbed over Au (1 1 1). Our adsorption calculations suggest that H{sub 2}O tended to block the active sites and inhibited the adsorption step, fully consistent with the rapid 1,3-butadiene conversion drop from above 40% to below 10% at low water concentration (<1200 ppm) in experiments. The transition state calculations indicate that water had little impact on the reaction step given slight change of energy barrier from 0.62 eV to 0.55 eV for the major route. This result validated the experimental finding that the conversion of 1,3-butadiene on Au/γ-Al{sub 2}O{sub 3} catalysts had only a slight decrease in a high water concentration range.

  7. 丙烯腈生产的高效精制工艺优化%Optimization of Efficient Refining Technology of Acrylonitrile Process

    Institute of Scientific and Technical Information of China (English)

    吴金海

    2011-01-01

    Cation exchange resin D001 was chosen to adsorb oxazole from acrylonitrile. The equilibrium adsorption capacity of resin D001 was 37. 08 mg · g-1. The adsorpion rate was above 99% with input flow rate of 2. 0 BV ? h-1 and temperatune of 20 °C , and desorpion rate was 100% with 5% HC1 as desorption reagent, 5% HC1 volume of 1. 2 BV, the elution flow rate of 1. 0 BV ? h-1 , soaking time of 6 h. By adding refining process of cation exchange resin, the content of oxazole in acrylonitrile of finished product tower was controlled above 40 mg · g-1 , the content of oxazole in acrylonitrile was controlled below 1 mg · g-1 , and the yield of acrylonitrile was increased above 0. 5%, which realized the efficient refinery of acrylonitrile.%采用阳离子交换树脂D001去除丙烯腈中(口恶)唑。D001的平衡吸附量为37.08 mg·g-1,在20℃、30℃、40℃、50℃下,D001对(口恶)唑的吸附符合Langmuir吸附等温方程。在进料流量为2.0 BV·h-1、体系温度为20℃时,丙烯腈中(口恶)唑的去除率达99%以上。采用5%的HCl为洗脱剂,在其用量为1.2 BV、洗脱速度为1 BV·h-1、浸泡时间为6 h的条件下,(口恶)唑的脱附率可达100%。在丙烯腈生产工艺中增加离子交换树脂吸附(口恶)唑工艺部分,可控制成品塔丙烯腈中(口恶)唑的含量在40 mg·g-1以上、丙烯腈产品中(口恶)唑的含量在1 mg·g-1以下,而且丙烯腈收率提高0.5%以上,实现了丙烯腈的高效精制。

  8. Homopolymerization of Ethylene, 1-Hexene, Styrene and Copolymerization of Styrene With 1,3-Cyclohexadiene Using (h5-Tetramethylcyclopentadienyldimethylsilyl(N-Ar’amido-TiCl2/MAO (Ar’=6-(2-(Diethylborylphenylpyrid-2-yl, Biphen-3-yl

    Directory of Open Access Journals (Sweden)

    Michael R. Buchmeiser

    2011-01-01

    Full Text Available The propensity of a half-sandwich (η5-tetramethylcyclopentadienyl dimethylsilylamido TiIV-based catalyst bearing an auxiliary diethylboryl-protected pyridyl moiety (Ti-8, activated by methylaluminoxane (MAO to homopolymerize α-olefins such as ethylene, 1-hexene and styrene as well as to copolymerize styrene with 1,3-cyclo-hexadiene is described. The reactivity of Ti-8 was investigated in comparison to a 6-(2-(diethylborylphenylpyrid-2-yl-free analogue (Ti-3.

  9. 苯乙烯生产现状和发展趋势%Status and development trends of styrene production

    Institute of Scientific and Technical Information of China (English)

    沈江; 陈俊士; 洪纯芬

    2011-01-01

    介绍了苯乙烯生产现状和国产化科技发展现状,指出装置规模大型化、原料来源多样化、生产技术创新化、催化剂开发深入化将是苯乙烯生产的发展趋势,归纳总结了今后可能的苯乙烯产业的发展目标.%The status of styrene industry and its localization technology in China are introduced in this paper. Enlargement of styrene production equipment,diverse sources of raw materials,innovation of technology and development of new catalysts are the trends of styrene production. The possible development objectives of the styrene production in the future are summarized as well.

  10. 44. Study the level of DNA breakage in workers exposed to styrene by single cell gel electrophoresis

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective: Study the level of DNA breakage in workers exposed to styrene. Methods: 35 workers aging from 18 to 40 exposed to styrene half a year above were observed as exposed group, in the mean time, 57 workers in the same district who hadn't been exposed to known genotoxicant were selected as control. Bloods of them were sampled and DNA lesions were detected by single cell gel electrophoresis. Results: Compared with control, the ratio between the length of Comet tail and the total length of Comet in exposed group significantly increased, especially it raised following the styrene concentration exposed, but it was not different among different working age groups. Conclusions: DNA is damaged by styrene, and it appears as dose-response relationship.

  11. Cationic Ring Opening Copolymerization of 1,3-Dioxolane with Styrene by Montmorillonite Maghnite-H+Catalyst

    OpenAIRE

    Nabil Hamam; Mohammed Issam Ferrahi; Mohammed Belbachir

    2016-01-01

    In the present work, the copolymerization of 1,3-Dioxolane (DXL) with Styrene (St) catalyzed by Maghnite-H+ a montmorillonite sheet silicate clay exchanged with protons, was investigated. The cationic ring opening polymerization was initiated by Maghnite-H+ in bulk. The copolymer obtained was characterized by 1H-NMR, DSC and IR spectroscopy. The studies done, such as the effect of the amount of catalyser on the syntheses of poly (DXL -co- Styrene).

  12. Cationic Ring Opening Copolymerization of 1,3-Dioxolane with Styrene by Montmorillonite Maghnite-H+Catalyst

    Directory of Open Access Journals (Sweden)

    Nabil Hamam

    2016-06-01

    Full Text Available In the present work, the copolymerization of 1,3-Dioxolane (DXL with Styrene (St catalyzed by Maghnite-H+ a montmorillonite sheet silicate clay exchanged with protons, was investigated. The cationic ring opening polymerization was initiated by Maghnite-H+ in bulk. The copolymer obtained was characterized by 1H-NMR, DSC and IR spectroscopy. The studies done, such as the effect of the amount of catalyser on the syntheses of poly (DXL -co- Styrene.

  13. 丁二烯/苯乙烯阴离子连续溶液共聚合研究%Studies on Anionic Continuous Solution Copolymerization of Butadiene/Styrene with n-BuLi Initiator

    Institute of Scientific and Technical Information of China (English)

    李洪泊; 孙建中; 胡俊杰; 周其云; 翁志学

    2002-01-01

    在2L的搅拌釜式反应器中,对以正丁基锂(n-BuLi)、THF和环己烷分别为引发剂、调节剂和溶剂的丁二烯/苯乙烯阴离子连续溶液共聚合进行了实验研究.用气相色谱、凝胶渗透色谱和核磁共振仪分别实测了单体转化率、共聚物的分子量分布和共聚物的微观结构.考察了平均停留时间和THF/Li+比值对丁苯连续共聚合的转化率、分子量及分子量分布和共聚物微观结构的影响.研究结果表明,在THF存在下,由n-BuLi引发剂引发的丁苯阴离子连续溶液共聚合可获得微观结构较合适的丁苯无规共聚物:平均停留时间对转化率有明显影响,而对共聚物的微观结构的影响较小:THF/Li+比值对聚合速率及共聚物中的结合苯乙烯含量有明显影响,对共聚物的微观结构如1,2-结构1,4-结构及顺反结构也有一定程度的影响,THF/Li+比值对共聚物的平均分子量有显著的影响,而对共聚物的分子量分布无明显影响.研究表明合适的THF/Li+比值为70.

  14. COUPLING REACTION OF LIVING BUTADIENE-STYRENE COPOLYMER WITH ACRYLOYL CHLORIDE%丙烯酰氯对丁苯共聚物活性链偶联反应的研究

    Institute of Scientific and Technical Information of China (English)

    徐日炜; 焦书科; 余鼎声; 张兴英; 侯元雪; 张洪敏

    2002-01-01

    以n-BuLi为引发剂,四氢呋喃(THF)为调节剂,抽余油为溶剂,采用丙烯酰氯为偶联剂对丁二烯-苯乙烯阴离子共聚体系进行偶联反应,研究了影响偶联反应的各种因素,如偶联剂用量、相对分子质量、偶联反应时间、偶联反应温度、THF用量、末端基团、单体浓度等;确定了偶联剂用量与聚合物相对臂数之间的关系及其偶联效率.

  15. The study of two-block styrene-butadiene copolymer%溶液聚合二元丁二烯-苯乙烯共聚物的研究

    Institute of Scientific and Technical Information of China (English)

    薛宏; 王军; 计福春; 张春庆; 李伟; 刘青

    2000-01-01

    以正丁基锂(n-BuLi)为引发剂,环己烷为溶剂,THF、2G、TMEDA为结构调节剂,合成了溶液聚合二元丁二烯、苯乙烯共聚物.研究结果表明:合成的共聚物不同嵌段微观结构不同,和普通溶聚丁苯橡胶相比,该共聚物不仅具有良好的物理机械力学性能,同时具有低滚动阻力和高抗湿滑性能.

  16. Study on the microstructure of anionic polymerization of butadiene on and styrene in ultrasonic%超声波对丁二烯/苯乙烯共聚的影响

    Institute of Scientific and Technical Information of China (English)

    韩伟健; 戴珍; 杨慧; 宗成中

    2006-01-01

    研究了超声波辐照对n-BuLi/2G/加氢汽油/丁二烯阴离子聚合的影响.实验表明,与无超声波辐照相比,较低温度下转化率降低,1H-NMR谱图表明,2G提高产物1,2含量的作用有所降低,共聚物接合苯乙烯,1,2PB含量降低,在2G/Li+=0.8时,cis/trans比例发生逆转,由顺式含量较高变为反式含量较高.

  17. Application of YH-05 Carboxylated Styrene-Butadiene Latex Binder in Coated Paper%YH-05羧基丁苯胶乳粘合剂在铜版纸中的应用

    Institute of Scientific and Technical Information of China (English)

    张杰

    2004-01-01

    讨论了羧基丁苯胶乳物化性能对铜版纸涂布性能的影响,对比了YH-05、Dow-675、SD-656三种羧基丁苯胶乳的成纸性能.结果表明,燕化公司研究院研制生产的YH-05羧基丁苯胶乳各项性能指标与Dow-675、SD-656相当.

  18. The effect of trichloroethylene and acrylonitrile on RNA and ribosome synthesis and ribosome content in Saccharomyces cells.

    Science.gov (United States)

    Lochmann, E R; Ehrlich, W; Mangir, M

    1984-04-01

    The effects of trichloroethylene (TCE) and acrylonitrile (ACN) on growth, RNA synthesis, ribosome synthesis, and ribosome content were tested in yeast cells. TCE causes a delay of the growth of a cell culture (prolongation of the lag phase), but does not cause inhibition. Cells exposed to increasing concentrations of ACN show increasing damage, so that, at a certain point of the growth curve, cell division stops altogether. Similar results were obtained when RNA synthesis was investigated: After treatment with TCE, the maximum RNA synthesis of the cell culture was retarded, but subsequently reached the same level as the untreated control cells. In the presence of ACN, however, the rate of RNA synthesis was lowered with increasing ACN concentrations. The same effect was observed upon investigation of ribosome synthesis: Whereas TCE produces only a slight effect, treatment with increasing concentrations of ACN leads to a substantial decrease in ribosome synthesis, and finally to total inhibition. Parallel to this, the content of free and membrane-bound ribosomes is diminished. Obviously, the decrease in ribosome content is caused not only by an inhibition of ribosome synthesis, but also by a degradation of existing ribosomes, as well as by induction of a ribosome-associated RNase. PMID:6714140

  19. Preparation of Mesoporous Carbons from Acrylonitrile-methyl Methacrylate Copolymer/Silica Nanocomposites Synthesized by in-situ Emulsion Polymerization

    Institute of Scientific and Technical Information of China (English)

    BAO Yongzhong; ZHAO Wenting; HUANG Zhiming

    2013-01-01

    Acrylonitrile-methyl methacrylate (AN-MMA) copolymer/silica nanocomposites were synthesized by in-situ emulsion polymerization initiated by 2,2′-azobis(2-amidinopropane) dihydrochloride absorbed onto colloidal silica particles,and the mesoporous carbon materials were prepared through carbonization of the obtained AN-MMA copolymer/silica nanocomposites,followed by HF etching.Thermogravimetric analysis of AN-MMA copolymer/silica nanocomposites showed that the carbon yield of copolymer was slightly decreased as silica particle incorporated.N2 adsorption-desorption,scan electron microscopy (SEM) and transmission electron microscopy (TEM) were used to characterize the structure and morphology of the mesoporous carbon materials.Both SEM and TEM results showed that disordered mesopores were formed in the obtained carbon material mainly through templating effect of silica nanoparticles.The diameter of mesopores was mainly distributed in the range from 5 nm to 15 nm.The mean pore diameter and total pore volume of the material increased as the mass fraction of silica in the nanocomposites increased from 0 to 24.93%.The significant increase of the mean pore diameter and the decrease of surface area for the carbon material prepared from the nanocomposite with 24.93% silica were caused by partial aggregation of silica nanoparticles in the polymer matrix.

  20. Molecular mechanism of gelation upon the addition of water to a solution of poly(acrylonitrile) in dimethylsulfoxide

    Science.gov (United States)

    Vettegren, V. I.; Kulik, V. B.; Savitskii, A. V.; Fetisov, O. I.; Usov, V. V.

    2010-05-01

    The solidification of a solution of poly(acrylonitrile) (PAN) in dimethylsulfoxide (DMSO) upon introduction of water into the solution is studied by Raman spectroscopy. In the absence of water, DMSO molecules are found to produce dipole-dipole bonds with PAN molecules. Upon the introduction of water, DMSO molecules produce hydrogen bonds with it and bands at 1005 and 1015 cm-1 appear in the Raman spectrum, which are assigned to the valence vibrations of S=O bonds involved in the hydrogen bonds. Simultaneously, water molecules produce hydrogen bonds with PAN molecules: R-C≡N...H-O-H...N≡C-R, where R is the carbon skeleton of a PAN molecule. Accordingly, a band at 2250 cm-1 arises in the Raman spectrum, which is assigned to the valence vibrations of C≡N bonds producing hydrogen bonds with a water molecule. When the water content is low and the DMSO concentration is high, the length of the hydrogen bonds varies in wide limits and the band at 2250 cm-1 is wide. As the water content rises, DMSO molecules come out of PAN, the variation of the hydrogen bond length in it decreases (the band at 2250 cm-1 narrows), and a high-viscosity system (gel) arises that consists of PAN molecules bonded to water molecules via “equally strong” hydrogen bonds.