• Elastomers and Composites
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• 제55권4호
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• pp.314-320
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• 2020

This study focused on experiments with polyethylene glycol (PEG) and glycidyl methacrylate (GMA), which are functional additives for water-expandable rubber. Polychloroprene rubber (CR)/superabsorbent polymer (SAP) composites were prepared and their cure behaviors, mechanical properties, water absorption rates, and surface morphology were measured based on the functional additives applied. When PEG and GMA were applied to the composites, the water absorption rate increased-including the initial rate-compared to that measured when functional additives were not used. The results also show that PEG has a hydrophilic functional group, which allows it to absorb more water, and GMA acts as a coupling agent between CR and SAP. However, with the introduction of functional additives, the cure rate slowed down and the mechanical properties also decreased.

• Elastomers and Composites
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• 제50권4호
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• pp.258-264
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• 2015

Rubber composites were prepared by precured CIIR pulverized at knead shear force in order to research the effects of the BR/PCP composites. The particle size of domain in BR/CIIR composites was decreased and homogeneously dispersed by the precured CIIR pulverized. However, it was difficult to use the product when the content is 40 phr and precured of 40%. BR/PCP composites have improved mechanical properies as compared that of the addition of simply cut chip composite.

• Elastomers and Composites
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• 제55권2호
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• pp.137-146
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• 2020

Part 1 provides a theoretical introduction of the hydrolysis mechanism, while Part 2 introduces other types of reaction mechanisms after hydrolysis in elastomer and PA66 composites. We reviewed the condensation reaction, which occurs after hydrolysis in bi-functional alkoxy silane (TESPD & TESPT), and investigated its effects on the mechanical properties of the composites. We also reviewed activators such as zinc soap, which enhances the mechanical properties of silica-silane-filled elastomer composites. The interaction parameter of silica-silane-filled elastomer composites [α_C (alpha C)] were also discussed. The effects of hydrolysis on the mechanical property changes in plastic composites were compared and reviewed.

• Elastomers and Composites
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• 제51권2호
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• pp.93-98
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• 2016

The composites of EVA/EPDM including aluminum trioxide (ATH) as a fire retardant were manufactured for the purpose of improving low temperature property and flame resistance in the rubbery materials. The ratio of EVA to EPDM didn't affect the flame resistance of the rubber composites. The addition of ATH resulted in increase of the flame resistance. In the evaluation of the cold resistance, the increasing EPDM content showed enhancement of cold resistance in the composites due to increasing low Tg EPDM. It was found out that tensile strengths of the composites showed a maximum value at 100 phr of ATH by reinforcing effect, but a minimum value at 200 phr of ATH owing to slippage between the flame retardant by the external stress. In the measurement of solvent resistance in tetrahydrofuran, the increasing ATH content yielded enhancement of solvent resistance by reducing swelling of the composite, and increasing EPDM content also resulted from increase of the solvent resistance by reduction of polarizability as well as increase of crosslink in the composites.

• Elastomers and Composites
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• 제53권3호
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• pp.175-180
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• 2018

Solution-styrene-butadiene rubber (SSBR) composites were manufactured using four kinds of fillers: silica-silane coated carbon black (SC-CB) hybrid, starch-SC-CB hybrid, pure silica, and pure starch. The influence of filler type on the mechanical properties of the rubber matrix was studied in this work. SC-CB was prepared by silane-graft-coating using vinyl triethoxy silane and carbon black, which enhanced the dispersion effect between the rubber matrix and the filler, and improved the mechanical properties of the compounds. The morphology of the composites was observed by field-emission scanning electron microscopy (FE-SEM). The thermal decomposition behavior of the composites was determined by thermogravimetric analysis (TGA), and the crosslinking behavior of the composites was tested using a rubber process analyzer (RPA). The hardness, tensile strength, swelling ratio, and gas transmittance rate of the composites were evaluated according to ASTM. The test results revealed that with the addition of SC-CB, the hybrid fillers, especially those blended with silica, showed a better reinforcement effect, the highest hardness and tensile strength, and stable thermal decomposition behavior. This implies that the silica-SC-CB hybrid filler has a notable mechanical reinforcement effect on the SSBR matrix. Because of self-crosslinking during its synthesis, the starch-SC-CB hybrid filler produced the most dense matrix, which improved the anti-gas transmittance property. The composites with the hybrid fillers had better anti-swelling properties as compared to the neat SSBR composite, which was due to the hydrophilicity of silica and starch.

• Carbon letters
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• 제18권
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• pp.1-10
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• 2016

Carbon blacks (CBs) have been widely used as reinforcing materials in advanced rubber composites. The mechanical properties of CB-reinforced rubber composites are mostly controlled by the extent of interfacial adhesion between the CBs and the rubber. Surface treatments are generally performed on CBs to introduce chemical functional groups on its surface. In this study, we review the effects of various surface treatment methods for CBs. In addition, the preparation and properties of CB-reinforced rubber composites are discussed.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 1999년도 춘계학술발표대회 논문집
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• pp.1.1-4
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• 1999

The toughening mechanism and fracture behavior of rubber/polymer composites were investigated with respect to two factors; (1) the composition ratio of polymers(PPO and PS which have a different chain flexibility) and (ii) the rubber particle size in PPO/PS blend system Izod impact test and fractographic observation of the fracture surface using scanning electron microscope were conducted, Finite element analysis were carried out to gain understanding of plastic deformation(shear yielding and crazing) of these materials.

• Elastomers and Composites
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• 제46권4호
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• pp.318-323
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• 2011

폐타이어고무분말을 재활용하기 위하여 방수시트용 고무분말 복합체를 제조하였으며, 수지 종류와 가교제의 함량이 복합체의 기계적 특성에 미치는 영향을 고찰하였다. EPDM이 부가됨에 따라 고무분말 PE 복합체의 신장율이 3배 이상 증가하는 현상을 나타내었다. 고무분말 충전 복합체에 가교제의 농도가 증가함에 따라 복합체의 강도가 증가하였으며, 특히 재생 폴리프로필렌을 사용한 경우 3배 이상 인장강도가 현저하게 높게 나타났다. 따라서 폴리프로필렌 블렌드물로 고무분말 복합체를 제조하는 경우 신재 폴리프로필렌을 사용하는 것 보다 재생 폴리프로필렌을 사용하는 것이 기계적 특성면에서 효과적인 것으로 나타났다.

• Macromolecular Research
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• 제16권5호
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• pp.404-410
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• 2008

In order to obtain 'value added products' from polypropylene (PP)/waste ground rubber tire powder (WGRT) composites, PP/WGRT microcellular foams were prepared via supercritical carbon dioxide. The effects of blend composition and processing condition on the cell size, cell density and relative density of PP/WGRT micro-cellular composites were studied. The results indicated that the microcellular structure was dependent on blend composition and processing condition. An increased content of waste ground rubber tire powder (WGRT) and maleic anhydride-grafted styrene-ethylene-butylene-styrene (SEBS-g-MA) reduced the cell size, and raised the cell density and relative density, whereas a higher saturation pressure increased the cell size, and reduced the cell density and relative density. With increasing saturation temperature, the cell size increased and the relative density decreased, whereas the cell density initially increased and then decreased.

• Carbon letters
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• 제9권2호
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• pp.115-120
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• 2008

Rubber reinforcing carbon black N330 was treated by physical activation under $CO_2$ to different degrees of burn-off. The mechanical properties indicating the reinforcement of SBR (Styrene-Butadiene Rubber) vulcanizates filled by activated carbon blacks, such as tensile strength, modulus at 300% strain and elongation at break were determined. During $CO_2$ activation of fresh carbon blacks, the development of microporous structure caused an increase of extremely large specific surface area and the porosity turned out to be an increasing function of the degree of burn-off. The tensile strength and modulus at 300% of activated carbon blacks filled rubber composites were improved at lower loading ratios of 20 and 30 phr, but decreased drastically after 30 phr, which is considered that it might be difficult to get a fully dispersed rubber mixture at higher loading ratios for fillers having very large specific surface areas. However, the Electromagnetic Interference (EMI) shielding effectiveness of SBR rubber composites having activated carbon black at 74% yield were improved at a large extent when compared to those having raw carbon black and increased significantly as a function of increasing loading ratio.