• Elastomers and Composites
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• 제50권2호
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• pp.110-118
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• 2015

In this study, diethylaminoethyl methacrylate-styrene-butadiene terpolymer (DEAEMA-SBR), in which diethylaminoethyl methacrylate (DEAEMA) was introduced to the SBR molecule as a third monomer, was synthesized by cold emulsion polymerization. It is expected that amine group introduced to a rubber molecule would improve dispersion of silica by the formation of hydrogen bond (or ionic coupling) between the amine group and silanol groups of silica surface. The chemical structure of DEAEMA-SBR was analyzed using proton nuclear magnetic resonance spectroscopy (H-NMR), Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC) and differential scanning calorimetry (DSC). Then, various properties of DEAEMA-SBR/silica composite such as crosslink density, bound rubber content, abrasion resistance, and mechanical properties were evaluated. As a result, bound rubber content and crosslink density of DEAEMA-SBR/silica compound were higher than those of the SBR 1721 composite. Abrasion resistance and moduli at 300% elongation of the DEAEMA-SBR/silica composite were better than those of SBR 1721 composite due to the high bound rubber content and crosslink density. These results are attributed to high affinity between DEAEMA-SBR and silica. The proposed study suggests that DEAEMA-SBR can help to improve mechanical properties and abrasion resistance of the tire tread part.

• Elastomers and Composites
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• 제58권4호
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• pp.179-190
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• 2023

The effect of the particle size and silica structure on the wear behavior of Silica/Styrene-Butadiene Rubber (SBR) compounds was investigated using a blade-type abrader and the findings were compared with those obtained with an Akron abrader. The compensated characteristic parameter (Ψ_c), which was the contributory factor of the combined effect of the particle size and filler structure, was introduced. This parameter was found to exhibit a linear relationship with the Young's modulus. The Young's modulus correlated more with Ψ_c than the uncompensated characteristic parameter (Ψ) modeled for carbon black. The wear rate and volume loss measured using a blade-type abrader and Akron abrader were respectively observed to be inversely proportional to Ψ_c, that is, the wear resistance of Silica/SBR compound improved as the particle size became smaller and the silica structure became intricate. The coefficient of determination (R²) obtained from the linear relationship between Ψ_c and wear rate was higher than those between Ψ_c and volume loss for the Silica/SBR compound. Thus, the blade-type abrader exhibited high potential to be used for accurately evaluating the effect of particle size and structural properties of silica on the wear behavior of SBR compounds.

• Elastomers and Composites
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• 제59권1호
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• pp.34-41
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• 2024

In this study, the effects of the type and content of silica on the mechanical and tear properties of chloroprene rubber (CR), which is mainly used as a jacket material for mining cables, were studied. The crosslinking density (ΔM) and reinforcing factor (α_f) defined using cure characteristics increased with increasing silica content, whereas the cure rate decreased. The hardness, tensile strength, and modulus of the CR compounds increased depending on the silica content and structural development. The reinforcing behavior of the silica-filled CR compounds according to the silica type and content showed the best fit with the Thomas equation of the predictive model. Tear strength was evaluated using two standard test methods, ASTM D470 and DIN VDE 0472-613, and the results were compared. The tear strength increased as the silica content increased, regardless of the test method, and the different tear strengths obtained by the two standard test methods showed a linear relationship with each other, indicating a high correlation.

• Elastomers and Composites
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• 제49권1호
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• pp.66-72
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• 2014

실리카 입자에 팽창흑연을 그라프트 시킴으로 카본코팅을 실시하였으며, 이를 확인하기 위하여 FT-IR, TGA, XPS 그리고 TEM 분석을 실시하였다. 코팅된 흑연의 결정특성은 XRD를 이용하여 확인하였으며, 카본 코팅된 실리카가 SBR 컴파운드의 유변학적 그리고 기계적 성질에 미치는 영향에 대하여 살펴보았다. 카본 코팅된 실리카를 이용한 경우 순수 실리카를 이용한 경우에 비하여 SBR 컴파운드의 유변학적 그리고 기계적 성질이 크게 향상됨을 알 수 있었다. 이러한 현상은 평형팽창비율과 bound 고무 양 변화로도 확인 할 수 있었다.

• 폴리머
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• 제36권2호
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• pp.235-244
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• 2012

본 연구에서는 thiazole 계 촉진제인 2-mercapto benzothiazole(MBT)의 첨가량을 변화시켜(0, 1, 2, 3, 4 phr) 실란/실리카로 충전된 천연고무 컴파운드에 첨가하여 가황속도, 물성, 고무-충전제간 상호작용계수(${\alpha}_F$), 가교밀도 및 탄젠트 델타($tan{\delta}$)에 미치는 영향을 비교 평가하였다. 촉진제의 첨가량이 증가할수록 $t_{s2}$, $t_{90}$ 가황시간은 빨라졌고 가교 밀도 및 300% 모듈러스는 증가하였다. 인장강도와 신장률 또한 증가하였으나 3 phr에서는 더 이상의 증가가 없었다. 그리고 상온에서의 $tan{\delta}$ 값은 $70^{\circ}C$에서보다 높은 값을 나타내었다. 촉진제의 함량변화는 천연고무-실란/실리카간 상호관계(${\alpha}_F$)에 큰 영향을 미치지 않는 것으로 관찰되었다. 가황속도에 미치는 메카니즘을 고찰하였다.

• 공업화학
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• 제22권4호
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• pp.411-415
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• 2011

본 연구에서는 화학적 구조가 다른 thiuram계 tetramethyl thiuram disulfide (TMTD), dipenta methylene thiuram tertasulfied (DPTT), thiazole계 2-mercapto benzothiazole (MBT), 2,2'-dithiobisbenzothiazole (MBTS), sulfenamide계 n-cyclohexyl benzothiazyl-2-sulfenamide (CBS), n-oxydiethylene benzo-thiazyl-2-sulfenamide (NOBS)를 사용하여 각각의 촉진제가 실리카가 충진된 천연고무의 가황 특성 및 기계적 물성에 미치는 영향을 비교 평가하였다. TMTD는 상대적으로 빠른 가류 속도와 높은 최대 토크값($T_{max}$), 우수한 기계적 물성을 보였고 MBT, MBTS는 상대적으로 중간 정도의 가황 시간과 $T_{max}$, 기계적 물성을 보였다. 마지막으로 NOBS는 느린 가황 시간과 낮은 기계적 물성을 나타낸 반면 중간 값의 $T_{max}$를 나타냈다.

• Elastomers and Composites
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• 제59권1호
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• pp.8-16
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• 2024

As regulations on greenhouse gas emission have strengthened globally, the demand for improved fuel efficiency in automobiles continues to rise. In response, the tire industry is actively conducting research to improve fuel efficiency by enhancing tire performance. In this study, silica-filled epoxidized natural rubber (ENR)/butadiene rubber (BR) blend compounds were manufactured according to ENR types and silica contents, and their physical properties and vulcanizate structure were evaluated. ENR-50, which has a higher epoxide content than ENR-25, exhibited stronger filler-rubber interaction, resulting in superior abrasion resistance. In addition, because of its high glass transition temperature (T_g), the wet grip performance of ENR-50 improved, even though the rolling resistance increased. Increasing the amount of silica had little effect on the abrasion resistance due to the increase in filler-rubber interaction and decrease in toughness. In addition, ENR-50 exhibited better wet grip performance; however, the rolling resistance increased. The results indicated that truck bus radial (TBR) tire tread compounds can be designed by applying ENR-50 to improve wear resistance and wet grip performance. In addition, by applying ENR-25 and reducing the silica contents improve fuel efficiency.

• Elastomers and Composites
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• 제37권2호
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• pp.86-98
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• 2002

본 연구에서는 실리카/카본블랙 혼합사용과 카본블랙 단독 사용의 경우 상온 또는 고온에서의 인장강도(modulus) 및 인열저항성, 내cutting성, 내crack성을 비교 평가하였다. 실리카와 카본블랙의 함량비 및 단계배합 방법을 통해 NR 가황물을 제조하였으며, 충전제의 함량은 60phr로 고정하였고, semi-EV 가황시스템을 적용하여 실험을 실시하였다. 실리카의 분산은 25phr이하일 때 양호하였으며, 실리카/카본블랙의 함량비가 25/35인 경우 인열에너지, 내crack특성, 내cutting특성이 가장 우수하였다. 충전제로써 카본블랙 단독사용과 실리카/카본블랙(25/35) 혼합사용의 경우를 비교해 보면, 열화에 따른 modulus 및 인장강도, 인열에너지는 실리카/카본블랙(25/35)을 사용한 시편이 더 낮은 감소율을 나타내었다. Cutting특성에서는 카본블랙 단독 사용보다는 실리카/카본블랙(25/35) 혼합사용의 경우가 더 높은 cutting 저항성을 나타내었다. 내crack 특성 또한 실리카/카본블랙(25/35)을 혼합사용한 경우가 온도에 따른 더 높은 변형에너지 완화율(Gp)에도 불구하고 더 낮은 크랙성장속도를 나타내었다.

• Elastomers and Composites
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• 제40권1호
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• pp.29-36
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• 2005

배합 조건과 공정은 충진제 분산, 점도, 결합고무 형성 등과 같은 고무 배합물의 특성에 영향을 준다. NBR과 SBR의 분리 첨가 배합이 NBR이 함유된 실리카로 보강된 고무 배합물의 특성에 미치는 영향에 대해 연구하였다. NBR 함량이 증가할수록 가교 시간과 속도는 빨라졌다. 가교밀도는 NBR 함량이 증가할수록 증가하였다. 결합고무량도 NBR 함량이 증가할수록 증가하였다. 결합 고무 중의 NBR 함량은 배합물 고무 중의 NBR 함량보다 높았다. 결합고무량은 동시첨가 배합의 경우보다 분리 첨가 배합의 경우 더 높았다. 가교 시간과 속도는 동시 첨가 배합의 경우보다 분리 첨가 배합때 더 느렸다. 가교밀도도 동시 첨가 배합의 경우보다 분리 첨가 배합의 경우 더 낮았다.

• Elastomers and Composites
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• 제58권4호
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• pp.161-172
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• 2023

Because particulate matter has emerged as a major contributor to air pollution, the tire industry has conducted studies to reduce particulate matters from tires by improving tire performance. In this study, we compared the conventional blending method, in which rubber, filler, and additives are mixed simultaneously, to the Y-blending method, in which masterbatches are blended. We manufactured carbon black (CB)-filled natural rubber (NR)/butadiene rubber (BR) blend and silica-filled epoxidized NR/BR blend compounds to compare the effects of the two blending methods on the physical properties of the compounds and the amount of particulate matter generated. The Y-blending method provided uniform filler distribution in the heterogeneous rubber matrix, improved processability, and exhibited low rolling resistance. This method also improved physical properties owing to the excellent filler-rubber interaction. The results obtained from measuring the generation of particulate matter indicated that, the Y-blending method reduced PM_2.5 particulate matter generation from the CB-filled and silica-filled compounds by 38% and 60%, and that of PM₁₀ by 29% and 67%, respectively. This confirmed the excellence of the Y-blending method regarding the physical properties of truck bus radial tire tread compounds and reduced particulate matter generated.