The Experts below are selected from a list of 95706 Experts worldwide ranked by ideXlab platform
Hanafi Ismail - One of the best experts on this subject based on the ideXlab platform.
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a study of ftir thermal properties and natural weathering test on nbrvirgin recycled with sbr blends
Polymer-plastics Technology and Engineering, 2012Co-Authors: Nik Noriman Zulkepli, Hanafi IsmailAbstract:The effects of styrene butadiene rubber/virgin acrylonitrile butadiene rubber (SBR/NBRv) blends and styrene butadiene rubber/recycled acrylonitrile butadiene rubber (SBR/NBRr) blends on properties such Fourier transform infrared (FTIR), thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) were carried out. Results indicated that, based on intensity of amine peak from FTIR at 85/15 blend ratio (R15) revealed optimum formation of crosslink between SBR and NBR either using virgin or NBRr. TG thermograms of SBR/NBRv blends of all ratios showed better onset thermal stability than SBR/NBRr blends. The change in the horizontal baseline from high to low energy level occurred in virgin NBR blends because the amount of reactive sites available in virgin NBR is higher compared to NBRr. Meanwhile NBRr blends showed Tc because the amount of crosslink occurred in these blends were slightly lower than NBRv blends. Up to 25 phr of NBRr, the tensile strength and elongation at break (Eb) retention...
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curing characteristics and mechanical and morphological properties of styrene butadiene rubber virgin acrylonitrile butadiene rubber sbr vnbr and styrene butadiene rubber recycled acrylonitrile butadiene rubber sbr rnbr blends
Polymer-plastics Technology and Engineering, 2008Co-Authors: N. Z. Noriman, Hanafi Ismail, Azura A RashidAbstract:Curing characteristics and mechanical and morphological properties of styrene butadiene rubber/virgin acrylonitrile-butadiene rubber (SBR/vNBR) and styrene butadiene rubber/recycled acrylonitrile-butadiene rubber (SBR/rNBR) were investigated. Results indicated that the curing characteristics, such as scorch time, t2, and cure time, t90, of SBR/vNBR and SBR/rNBR blends decreased with increasing vNBR and rNBR content. At similar blend ratios, particularly up to 15 phr, SBR/rNBR blends exhibited higher t2 and t90 compared with SBR/vNBR blends. Minimum torque (ML) and maximum torque (MH) of SBR/vNBR blends significantly increased with increasing vNBR content. For SBR/rNBR blends, ML increased with increasing rNBR content, but MH exhibited the opposite trend. Tensile strength, elongation at break (Eb), resilience, and fatigue decreased with increasing virgin and recycled NBR content in both blends. Up to 15 phr, the tensile strength, Eb and fatigue life (Kc) of SBR/rNBR blends were higher than in SBR/vNBR blen...
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the effect of a compatibilizer on curing characteristics mechanical properties and oil resistance of styrene butadiene rubber epoxidized natural rubber blends
European Polymer Journal, 2001Co-Authors: Hanafi Ismail, H. M. HairunezamAbstract:Abstract The effect of a compatibilizer, styrene–(epoxidized butadiene)–styrene triblock copolymer (ESBS) on curing characteristics, mechanical properties and oil resistance of styrene butadiene rubber (SBR) and epoxidized natural rubber (ENR) blends was examined. The results indicate that the increasing compositions of ENR and the presence of ESBS improve processability, tensile strength, tear strength and tensile modulus of SBR/ENR blends. The scorch time, t 2 and cure time, t 90 decrease with increasing compositions of ENR in the blend. The presence of ESBS exhibits a beneficial effect by increasing the scorch time and decreasing the cure time of the SBR/ENR blends. The presence of ESBS also resulted in SBR/ENR blends having an oil resistance better than the similar blends without ESBS.
Chen Xinfang - One of the best experts on this subject based on the ideXlab platform.
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variation with radiation dose of tensile strength and elongation at break of styrene butadiene styrene triblock copolymer
Polymer, 1994Co-Authors: Yang Huai, Jiang You, Li Xiangshan, Zhao Zhudi, Chen XinfangAbstract:Abstract The variation of tensile strength and elongation at break of Styrene-Butadiene-Styrene triblock copolymer containing 34.1, 40.0 and 52.5% styrene have been studied with respect to their morphology and the extent of crosslinking produced by irradiation with 60Co rays. We assume that the existence of microphase separation between polybutadiene (PB) and polystyrene domains and entanglements between PB segments result in the unusual variation of the two characteristics with radiation dose, which is different from that in common elastomers and blends.
Jianmin Chen - One of the best experts on this subject based on the ideXlab platform.
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understanding the mechanical and tribological properties of solution styrene butadiene rubber composites based on partially graphene oxide
European Polymer Journal, 2017Co-Authors: Lei Chen, Huidi Zhou, Haichao Zhao, Jianmin ChenAbstract:Poor dispersion of graphene in non-polar polymer matrices creates composites with limited applications. A method to improve the dispersion of graphene in solution styrene butadiene (SSBR) and butadiene rubber (BR) via grafting polystyrene (PS) or poly(styrene-co-isoprene) (PSI) on the surface of graphene oxide (GO) is examined. Composites of SSBR-BR with graphene as well as SSBR-BR with GO-PS (or GO-PSI) were prepared by open-mill mixing and vulcanization. Improved dispersion of GO in SSBR-BR composites substantially increases both the tensile strength and the wear resistance properties compared to neat SSBR-BR composites at low loads. More importantly, the wear test results and corresponding wear mechanisms of the all SSBR-BR composites were discussed at different loads.
G D Airey - One of the best experts on this subject based on the ideXlab platform.
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styrene butadiene styrene polymer modification of road bitumens
Journal of Materials Science, 2004Co-Authors: G D AireyAbstract:This paper describes the polymer modification of road bitumens with SBS. Six polymer modified bitumens (PMBs) were produced by mixing bitumen from two crude oil sources with an SBS copolymer at three polymer contents. The rheological characteristics of the SBS PMBs were analysed by means of dynamic mechanical analysis using a dynamic shear rheometer (DSR). The results of the investigation indicate that the degree of SBS modification is a function of bitumen source, bitumen-polymer compatibility and polymer concentration. When the polymer concentration and bitumen-polymer compatibility allow a continuous polymer network to be established, modification is provided by a highly elastic network which increases the viscosity, stiffness and elastic response of the PMB, particularly at high service temperatures. However, ageing of the SBS PMBs tends to result in a reduction of the molecular size of the SBS copolymer with a decrease in the elastic response of the modified road bitumen.
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rheological properties of styrene butadiene styrene polymer modified road bitumens
Fuel, 2003Co-Authors: G D AireyAbstract:Abstract The use of polymers for the modification of bitumen in road paving applications has been growing rapidly over the last decade as government authorities and paving contractors seek to improve road life in the face of increased traffic. Currently, the most commonly used polymer for bitumen modification is the elastomer styrene butadiene styrene (SBS) followed by other polymers such as styrene butadiene rubber, ethylene vinyl acetate and polyethylene. This paper describes the polymer modification of two penetration grade bitumens with SBS. Six polymer modified bitumens (PMBs) were produced by mixing the bitumens from two crude oil sources with a linear SBS copolymer at three polymer contents. The rheological characteristics of the SBS PMBs were analysed by means of conventional as well as dynamic mechanical analysis using a dynamic shear rheometer (DSR). The results of the investigation indicate that the degree of SBS modification is a function of bitumen source, bitumen–polymer compatibility and polymer concentration, with the higher polymer concentrations in a high aromatic content bitumen producing a highly elastic network which increases the viscosity, complex modulus and elastic response of the PMB, particularly at high service temperatures. However, ageing of the SBS PMBs tends to result in a reduction of the molecular size of the SBS copolymer with a decrease in the elastic response of the modified road bitumen.
Elizabeth Delzell - One of the best experts on this subject based on the ideXlab platform.
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chemical exposures in the synthetic rubber industry and lymphohematopoietic cancer mortality
Journal of Occupational and Environmental Medicine, 2005Co-Authors: Maurizio Macaluso, Nalini Sathiakumar, John J Graff, George Maldonado, Robert Matthews, Elizabeth DelzellAbstract:Objective: This study evaluated the association between exposure to several chemicals and mortality from lymphohematopoietic cancer (LHC) among 16,579 synthetic rubber industry workers who were followed up from 1943 to 1998. Methods: Poisson regression analyses examined LHC rates in relation to butadiene, styrene, and DMDTC exposure. Models provided maximum likelihood estimates of the relative rate for the contrast between categories of one agent, adjusting for other agents and for additional potential confounders. Results: Cumulative exposure to 1,3-butadiene was associated positively with all leukemia (relative rates of 1.0, 1.4, 1.2, 2.9, and 3.7, respectively, for exposures of 0, >0 to <33.7, 33.7 to < 184.7, 184.7 to < 425.0, and 425.0+ ppm-years), chronic myelogenous leukemia and to a lesser extent with chronic lymphocjtic leukemia. Adjusting for styrene and DMDTC attenuated these associations. After controlling for butadiene, neither styrene nor DMDTC displayed a consistent exposure-response trend with all leukemia, chronic myelogenous leukemia, or chronic lymphocytic leukemia. Conclusions: This study found a positive association between butadiene and leukemia that was not explained by exposure to other agents examined.
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leukemia and cumulative exposure to butadiene styrene and benzene among workers in the synthetic rubber industry
Toxicology, 1996Co-Authors: Maurizio Macaluso, Rodney R Larson, Elizabeth Delzell, Nalini Sathiakumar, Mary Hovinga, Jim A Julian, D C F Muir, Philip A ColeAbstract:Retrospective, quantitative estimates of exposure to 1,3-butadiene, styrene and benzene were developed for a follow-up study of leukemia mortality among 16610 subjects employed at six North American styrene-butadiene rubber manufacturing plants (418846 person-years, 58 leukemia deaths). The estimation procedure entailed identifying work areas within each manufacturing process, historical changes in exposure potential and specific tasks involving exposure, and using mathematical models to calculate job- and time-period-specific average exposures. The resulting estimates were linked with the subjects' work histories to obtain cumulative exposure estimates, which were employed in stratified and Poisson regression analyses of mortality rates. Mantel-Haenszel rate ratios adjusted by race, age, and cumulative styrene exposure increase with cumulative butadiene exposure from 1 in the nonexposed category to 4.5 in the category of 80 ppm-years or more (P = 0.01). The risk pattern is less clear and statistically nonsignificant for styrene exposure. A trend of increasing risk with butadiene exposure is still present after exclusion of the nonexposed category (P = 0.03). A parsimonious interpretation of the findings presented here, in light of previous epidemiologic studies, is that exposure to butadiene in the synthetic rubber industry produces a dose-related increase in the occurrence of leukemia.
