• Macromolecular Research
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• 제10권6호
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• pp.345-358
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• 2002

The electrical conductivity during vulcanization process was measured as a function of time for the system of TiC loaded styrene-butadiene rubber (SBR) composites. The phenomenon of negative and positive temperature coefficients of conductivity and its conduction mechanism were also studied for the SBR polymeric composites. The current-voltage characteristics of the polymeric composites were non-linear in high voltage and showed a switching effect. The effects of temperature on the thermal conductivity and effective dielectric constant were measured. The measured parameters were found to be dependent on TiC concentration. The electromagnetic wave shielding (EMS) of the SBR-TiC polymeric composite was also examined. The SBR filled with TiC could be expected to be promising novel smart polymeric composites for self-electrical heating, temperature sensor, time delay switching, and electro-magnetic wave shielding effectiveness.

• Elastomers and Composites
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• 제53권3호
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• pp.109-123
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• 2018

The effect of the silica content on the state and properties of silica-filled styrene-butadiene rubber/butadiene rubber (SBR/BR) compounds containing coupling and dispersion agents was evaluated by varying the content of silica from 50 to 120 phr. Bis-[(triethoxysilyl)propyl] tetrasulfide (TESPT) and zinc 2-ethylhexanoate (ZEH) were used as the coupling and dispersion agents, respectively. The maximum silica content in the pristine material was 80 phr, which increased to 120 phr upon the addition of TESPT and ZEH. The incorporation of TESPT considerably improved most of the rubber properties due to its coupling action and the suppression of silica flocculation, while further addition of ZEH resulted in additional improvements. The properties of the rubber compounds with different silica contents can be fully explained either by an enhancement of the rubber-silica interactions or by their deterioration due to an excessive amount of silica aggregates.

• Carbon letters
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• 제27권
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• pp.72-80
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• 2018

In the present work, a comparative study of the mechanical behavior of two series of elastomeric composites, based on carboxylated styrene butadiene rubber (X-SBR) and reinforced with rice bran carbon (RBC) and graphite, is reported. Hybrid composites of X-SBR filled with RBC-graphite were also investigated in terms of the cure characteristics, hardness, tensile properties, abrasion resistance, and swelling. It was observed that the cure times decreased with the incorporation of a carbon filler whereas the torque difference, tensile strength, tensile modulus, hardness, and swelling resistance increased compared to the neat X-SBR revealing a favorable characteristic of crosslinking. Dynamic rheological analysis showed that the G' values of the composites, upon the addition of RBC-graphite, were changed to some extent. This demonstrates that the presence of a strongly developed network of fillers will ensure a reinforcing characteristic in a polymer matrix.

• Elastomers and Composites
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• 제28권4호
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• pp.267-273
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• 1993

A number of hydrophilic acrylic comonomers were incorporated into styrene-butadiene soap-free emulsion polymerization. It was found that reaction rate decreased according to : AN>AA>MMA>EA>IA>AAM>MA>HEMA. It was also observed that reaction rate increased with decreasing H-bonding factor contribution to the solubility parameter of the hydrophilic comonoer. The SBR latexes were very monodisperse with the particle size distribution of $1.03{\times}1.12$. Since growth rate is proportional to polymerization time, the difference in conversion rates between various comonomers was resulted from the particle number density of SBR latexes for the various hydrophilic comonomers. It was also found that the colloidal stability of the latexes was excellent because no external emulsifier was incorporated.

• Macromolecular Research
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• 제10권6호
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• pp.369-372
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• 2002

The use of ZnO and stearic acid is very well known in sulfenamide accelerated sulfur vulcanization of diene elastomers. Zn-ion coated nano filler has been developed and tested, in styrene-butadiene rubber (SBR) as sulfur vulcanizing activator cum reinforcing filler. In this study Zinc oxide has been replaced by the Zn-ion coated nano silica filler with an aim to study the dual role of this nanofiller in SBR. The presence of Zn-ion on the nano silica filler surface activates the sulfur vulcanization by involving Zn++ in to the sulfurating complex formed with thiazole from sulfenamide. The increase of Zn-ion, on the nanofiller, decrease the scorch safety of the elastomer compound but increase the tensile strength, state of cure and tear strength and attain maximum at its 10% level. The presence of stearic acid increases the rate of vulcanization. Replacement of stearic acid with mono-stearate, however, increases the vulcanization rate but decrease the ultimate state of cure. A mechanistic scheme involving dual function of this nanofiller has been suggested.

• Elastomers and Composites
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• 제36권1호
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• pp.37-43
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• 2001

실리카와 카본블랙으로 보강된 SBR 배합물의 가황 특성과 bound rubber 함량 그리고 가황물의 물성에 보강제의 조성비가 미치는 영향을 연구하였다. 고무 배합물의 보강제 총 함량은 80.0 phr 이다. Bound rubber 함량은 실리카 함랑비가 증가할수록 증가하였고 점도 역시 증가하였는데, 특히 실리카 함량이 60.0 phr 이상일 때는 점도의 증가폭이 두드러지게 높아졌다. 가황시간은 실리카 함량이 증가할수록 느려졌고 가황 속도도 느려졌다. 실리카 함량비가 증가할수록 델타 토크가 증가함에도 불구하고 모둘러스는 감소하는 경향을 보였다. $60^{\circ}C$에서의 tan ${\delta}$ 값은 실리카 함량이 증가할수록 감소하였다.

• Carbon letters
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• 제10권4호
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• pp.320-324
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• 2009

We investigated the effect of diameter and content of carbon nanotubes (CNTs) on the physical properties of styrenebutadiene rubber (SBR)/CNTs nanocomposites. CNTs-reinforced SBR nanocomposites were prepared by the melt mixing process. CNTs with different diameters were synthesized by the chemical vapor deposition method (CVD). In this work, the mechanical property and other physical properties of SBR/CNTS nanocomposites were discussed as a function of the content and diameter of CNTs.

• 콘크리트학회논문집
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• 제14권3호
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• pp.315-320
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• 2002

본 연구에서는 고로슬래그 미분말을 이용한 SBR혼입 폴리머 시멘트 콘크리트의 강도 성상에 미치는 고로슬래그 치환율 및 폴리머 결합재비의 영향에 대하여 구명하였다. 그 결과, 고로슬래그 미분말을 이용한 SBR혼입 폴리머 시멘트 콘크리트의 압축, 인장 및 휨강도는 폴리머-결합재비 및 고로슬래그 치환율의 증가에 따라 증가하였으며, 고로슬래그 치환율 40%에서 가장 높은 강도를 나타내었다. 특히 고로슬래그 치환율 40%의 SBR혼입 폴리머 시멘트 콘크리트의 인장 및 휨강도는 폴리머 미혼입의 강도보다 약 2배 이상의 높은 강도를 보였다. 이와 같이 높은 강도의 발현은 SBR 폴리머의 높은 인장강도와 SBR라텍스의 혼입에 의한 시멘트 수화물과 골재간의 접착성이 개선되었기 때문이라 판단된다.

• 콘크리트학회지
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• 제8권6호
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• pp.163-172
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• 1996

최근 많은 양의 폐타이어가 발생됨에 따라 사회적 문제로 대두되고 있는 실정이며, 이에 대한 재활용은 각 분야에서 활발하게 연구되고 있다. 건설 분야에서는 폐타이어를 냉각 분쇄하여 만든 분말을 시멘트 콘크리트에 혼입하여 사용하는 연구가 많이 수행되고 있다. 시멘트 콘크리트에 폐타이어 분말을 혼입하여 사용할 때는 폐타이어 분말과 시멘트경화체 사이에서 접착성의 문제로 기초적 성질이 저감된다. 본 연구에서는 시멘트 모르터 내부에서 폐타이어 분말의 접착력을 증진시키기 위하여 시멘트 혼화용 폴리머 중의 하나인 스티렌 부타디엔 고무(SBR)라텍스를 사용하여 기초적 성질을 개선하고자 하였다. 실험결과 SBR 코팅 폐타이어 분말을 혼입한 시멘트 모르터는 코팅하지 않은 폐타이어 분말을 사용한 경우보다 기초적 성질이 개선되는 것으로 나타났으며, 또한 폴리머 시멘트비 10%를 사용한 SBR 라텍스 혼입 폴리머 시멘트 모르터의 경우에도 기초적 성질이 개선되었다.

• Macromolecular Research
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• 제9권3호
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• pp.157-163
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• 2001

The influences of carbon black loading and cure type on the cure characteristics including kinetics and dynamic mechanical properties were investigated for a styrene-butadiene rubber (SBR). The rate constants of accelerated sulfur vulcanization reaction at three different temperatures were determined using a cure rheometer, and they were compared with those from the direct measurement of sulfur concentration. The strain softening behavior under dynamic deformation, known as the Payne effect was also discussed depending on the carbon black loading and cure type.