• Elastomers and Composites
• /
• 제53권4호
• /
• pp.195-201
• /
• 2018

Three kinds of rubber compounds were prepared, and their underwater acoustical properties were investigated for anechoic coating. Dynamic mechanical properties of the rubber compounds were measured using a dynamic mechanical analyzer and extended to 100 kHz using time-temperature superposition. The sound speed, reflection coefficient, and attenuation constant were calculated. Silicone rubber showed the lowest reflection coefficient, and nitrile rubber showed the highest attenuation constant. The acoustic properties of nitrile rubber compounds with various compositions were investigated. The sound speed, reflection coefficient, and transmission coefficient of the nitrile rubber in the frequency range of 200-1000 kHz were measured in a water-filled tank.

• Macromolecular Research
• /
• 제14권2호
• /
• pp.187-193
• /
• 2006

Organoclay, was applied as a filler, in place of carbon black and silica, to a natural rubber (NR)/butadiene rubber (BR) blend. A compounding method was used to disperse and separate the layered silicates. The effect of a coupling agent on the vulcanizates was evaluated using both the silica and organoclay filled compounds. After the compounding processes were completed, the XRD diffraction peaks disappeared, but then reappeared after vulcanization. The scorch times for the organoclay-filled compounds were very short compared to those for carbon black and silica-filled compounds. The organoclay-filled compounds showed high values of tensile strength, modulus, tear energy, and elongation at the break. When ranked by viscosity, the compounds appeared in the following order: silica > silica (Si-69) > organoclay > organoclay (Si-69) > carbon black. Fractional hysteresis, tensile set, and wear rates were very consistent with the viscosity of the vulcanizates. The Si 69 coupling agent increased reversion resistance, the maximum torque values in the ODR, modulus, and wear resistance, but decreased elongation at the break, fractional hysteresis, and tension set of the vulcanizates.

• Elastomers and Composites
• /
• 제58권3호
• /
• pp.103-111
• /
• 2023

The abrasion resistances of silica-filled styrene-butadiene rubber (SBR) compounds prepared with and without dicyclopentadiene resin (SBR-R and SBR-0, respectively) were studied using four different abrasion testers, namely cut and chip (CC), Lambourn, DIN, and laboratory abrasion tester (LAT100). The effect of the resin on the abrasion behavior was elucidated by analyzing the morphologies and size distributions of wear particles. All the wear particles had rough surfaces, but those obtained in the Lambourn abrasion test exhibited relatively smooth surfaces. The size distributions of the wear particles showed different trends depending on the abrasion tester and the rubber compound; however, most of the wear particles were larger than 1000 ㎛. The SBR-R sample showed a wide range of particle sizes (from 63 ㎛) in the LAT100 abrasion test and majority of the wear particles were 500-1000 ㎛, whereas the SBR-0 sample had the most distribution of larger than 1000 ㎛. The abrasion rates of SBR-0 sample were lower than those of the SBR-R sample for the CC and LAT100 abrasion tests, but the Lambourn abrasion test result showed the opposite trend. Addition of the resin influenced the abrasion behavior, however the effect varied depending on the type of abrasion tests.

• Elastomers and Composites
• /
• 제47권2호
• /
• pp.156-161
• /
• 2012

공기와 증류수에서 노화시킨 천연고무 복합체의 원형 변형으로부터의 회복 거동의 차이를 연구하였다. 공기에서 노화시킨 시험편의 회복률이 증류수에서 노화시킨 것보다 더 컸다. 충진제로 보강한 시험편의 회복속도가 비충진 시험편보다 더 빨랐다. 카본블랙으로 보강한 시험편의 회복속도가 실리카로 보강한 시험편보다 더 빨랐다. 노화 매질에 따른 회복 거동의 차이는 가교밀도 변화와 아닐링 효과로 설명하였다.

• Elastomers and Composites
• /
• 제44권3호
• /
• pp.252-259
• /
• 2009

양기능성실란(TESPD)이 실리카가 함유된 SBR 복합 소재에 첨가되었을 시 그에 따른 가교특성, 가공정도, 물리적 특성들에 미치는 영향을 조사하였다. TESPD를 첨가한 SBR 복합 소재는 TESPD가 실리카와 고무를 화학적으로 결합하여 3차원적인 구조를 형성함으로해서 가교밀도가 증가하였고, 이에 따라 기계적 강도가 증가하였다. 이는 또한 TESPD를 첨가하지 않은 소재와 비교했을 시 가공성이 증가하였다.

• Elastomers and Composites
• /
• 제45권3호
• /
• pp.223-229
• /
• 2010

가공기기의 기하학적 구조(geometry)가 실리카 분산에 대해 미치는 영향을 알아보기 위해서 롤밀(two roll mill)과 밀폐식 혼합기(internal mixer)를 사용하여 실리카가 충전된 부틸고무 가황물을 제조하여 가황특성, 인장특성 및 실리카 분산을 비교하였다. 가공 시, 롤밀을 사용하여 제조한 배합물은 밀폐식 혼합기를 사용하여 제조한 배합물보다 경화 속도($t_{90}$)는 약간 느렸으나, 긴 유도시간($ts_2$), 높은 최대 토크 값($T_{max}$)을 보였다. 또한 롤밀을 사용하여 제조한 배합물은 실리카 입자의 분산 및 기계적 물성의 특성에 있어서 밀폐식 혼합기를 사용했을시 보다 상대적으로 우수함을 보였다.

• Elastomers and Composites
• /
• 제34권3호
• /
• pp.212-221
• /
• 1999

Mechanical properties of polypropylene filled with recycled rubber dusts obtained from the buffing process in sport shoe sole manufacture were investigated. The use of these dusts eliminates the need for the size reduction process which is usually employed in rubber recycling. Two different waxes, polypropylene wax and ethylene vinyl acetate wax, were used in the PP/rubber dust compound. Two different processes, extrusion and injection moulding, were used to study the influence of the blends on the properties. The waxes gave significant improvement in the shaping of the extrudate. It was found that the impact strength of the injection moulded samples were higher than the extruded samples and the virgin PP. The tensile properties (yield stress and modulus) were dependent on the amount of rubber dust addition. An increase in the rubber dust loading gave lower yield stress and modulus.

• Elastomers and Composites
• /
• 제53권1호
• /
• pp.6-12
• /
• 2018

Styrene-butadiene Rubber (SBR) Latex composites, incorporated with cellulose/starch-silica hybrids synthesized by gel-adsorption method, were filled into rubber by the latex compounding method. The structure morphology, mechanical properties, and thermodynamic properties of gel-silica hybrids were characterized. The states of hybrids which used as fillers were also characterized by SEM. As the fillers ratio increased, the difference for storage modulus of samples had been morphology by rubber process analyzer (RPA). Then, as more fillers ratio was filled into the matrix, the best tensile strength result, and the largest modulus value were also proved by UTM and RPA. As for thermal stability, increase in the ratio of fillers led to higher initial decomposition temperature, which was also proved by TGA. The swelling ratio of samples has also been characterized. From the results of all the tests, cellulose-silica hybrid showed the best results as a filler, and the best filling ratio of this hybrid is about 10 phr, which has the best storage modulus and great tensile strength.

• Elastomers and Composites
• /
• 제55권3호
• /
• pp.167-175
• /
• 2020

Various studies have been conducted to improve silica dispersion of silica filled tire tread compounds; among them, silica wet masterbatch (WMB) technology is known to be suitable for manufacturing silica filled compounds that have high silica content and high dispersibility. Till now, the WMB study is focused on the natural rubber (NR) or emulsion styrene-butadiene rubber (ESBR) that does not have a silica-affinity functional group, and a study of NR or ESBR having a silica-affinity functional group is still not well known. Unlike the dry masterbatch technology, the WMB technology can solve the problems associated with the high Mooney viscosity when applied to silica-friendly rubber. However, a coagulant suitable for each functional group has not yet been determined. Therefore, in this study, different coagulant applied silica WMB was prepared by applying calcium chloride, sulfuric acid, acetic acid, and propionic acid by using a carboxyl group functionalized reversible addition fragmentation chain transfer ESBR. The evaluation of the WMB compounds revealed that the calcium chloride added WMB compound showed excellent silica dispersion, abrasion resistance, and rolling resistance.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2001년도 학술논문발표회
• /
• pp.163-168
• /
• 2001

This study examinated the application in construction field and the development of waterproofing material system by the spray water-soluble rubber asphalt to solve the problems of synthetic polymer sheet and gio membrane(A mat sheet of Bentonite) that had been used domestic waterproofing material in advance. As the result of study, characters of study water-souble rubber asphalt are the follows; 1) The amount of water absorption was '0.06'g and the seepage quantity was '0'g in result. 2) The tensile strength was about 30.7kgf/$cm^2$ and the elongation was about 72.4% in result. 3) After reliance of temperature test had been ended, the tensile strength was about 72.4kg/$cm^2$ in low temperature and about 30.7kgf/$cm^2$ in normal temperature. 4) After acid and alkaline treatment had been ended, the tensile strength was about 19.7kgf/$cm^2$ and about 21.9kgf/$cm^2$ in result. 5) After chlorine ion treatment had been ended, the tensile strength was 28.5kgf/$cm^2$ and the elongation was 250% in result. So, this study can propose the spray water-soluble rubber asphalt to satisfy the security and durability of waste filled land.