• 접착 및 계면
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• 제4권3호
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• pp.1-8
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• 2003

철판에 도금한 아연을 구리이온으로 치환하는 치환도금법과 철판에 직접 구리를 증착하는 진공증착법으로 두께가 다른 구리박막 피복철판을 제조하여 배합고무와 접착성질을 조사하였다. 구리박막 피복철판과 배합고무의 접착세기는 제조방법에 관계없이 구리박막 두께에 따라 결정되었다. 구리박막이 75 nm보다 얇으면 안정한 접착층이 형성되어 황동판에 못지 않게 고무와 강하게 접착되었으나, 90 nm보다 두터우면 구리황화물이 지나치게 성정하여 접착세기가 약하였다.

• Macromolecular Research
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• 제8권6호
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• pp.285-291
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• 2000

Influence of silane coupling agent, bis-(3-(triethoxisilyl)-propyl)-tetrassulfide, on cure characteristics and bound rubber content of filled styrene-butadiene rubber (SBR) compounds and on physical properties of the vulcanizates was studied. Carbon black-filled and silica-filled compounds were compared. Content of the bound rubber increased with increased content of the silane coupling agent and this trend was shown more clearly in the silica-filled compounds. Optimum cure time of the carbon black-filled compound increased with increase of the silane content, while that of the silica-filled one decreased. Cure rate of the carbon black-filled compound became slower as the silane content increased while that of the silica-filled one became faster. By increasing the silane content, the minimum torque decreased and the delta torque increased. Physical properties of the silica-filled vulcanizate were found to be improved by adding the silane coupling agent. However, for the carbon black-filled vulcanizates, the tensile strength and tear resistance decreased with increase of the silane content. The differences between the carbon black-filled and silica-filled compounds were explained by difference in the reactivities of the fillers with the silane.

• Elastomers and Composites
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• 제57권4호
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• pp.129-137
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• 2022

Low molecular weight liquid butadiene rubber (LqBR) is a processing aid that can resolve the migration problem of tire tread compounds. Various studies are being conducted to replace the petroleum-based processing oil with LqBR. However, the effect of the loading time of LqBR in the compounding process on silica dispersion and vulcanizate properties is not well known. In this study, we analyzed silica dispersion, vulcanizate properties, and viscoelastic properties of silica-filled tire tread compound according to the processing aid type (TDAE oil, non-functional LqBR) and, silane terminated LqBR) and input timing. In the non-functional LqBR compounds, the 'with TESPT' mixing procedure showed excellent dynamic viscoelastic properties while silane-terminated LqBR compounds showed that the 'after TESPT' mixing procedure was good for 300% modulus and abrasion resistance.

• Elastomers and Composites
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• 제33권4호
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• pp.231-237
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• 1998

보강성 충전제가 첨가된 고무블렌드의 물리적 특성을 조사하기 위해 카본블랙이 첨가된 유화중합 고무블렌드와 실란이 커플링된 실리카가 첨가된 용액중합 고무블렌드의 가황특성, 점탄성특성, 내마모 및 고무보강성 평가하였다. 유화중합 고무블렌드는 가장 높은 총결합고무량을 나타냈으나, 용액중합 고무블렌드는 고무블렌드 비율에 관계없이 일정한 총결합고무량을 나타내었다. 고무의 미세구조중 비닐 및 스틸렌 함량이 낮을수록, 배합고무중 총결합고무량이 높을수록 가황속도는 빠르게 나타났으며, 고무보강성 지표인 모듈러스는 총결합고무량과 선형적인 관계를 나타냈다. 많은 PICO 손실량은 고무의 미세구조중 비닐 및 스틸렌 함량이 증가할 때 나타났으나, 적은 PICO 손실량은 실란이 커프링된 실리카를 함유한 용액중합 고무블렌드에서 부타디엔의 비율이 증가할 때 관측되었다. 용액중합 고무블렌드는 유화중합 고무블렌드에 비해 $0^{\circ}C$에서 높은 손실계수, $60^{\circ}C$에서는 낮은 손실계수를 나타내었다.

• 공업화학
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• 제22권2호
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• pp.144-148
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• 2011

본 연구에서는 화학적 구조가 다른 thiuram 계 촉진제인 TMTD (tetramethyl thiuram disulfide), thiazole 계 촉진제인 MBTS (2,2-dithiobis(benzothiazole)), sulfenamide 계 촉진제인 CBS (n-cyclohexyl benzothiazyl-2-sulfenamide)를 사용하여 각각의 촉진제가 실리카가 충전된 천연고무의 가황 특성에 미치는 영향을 비교 평가하였다. TMTD는 상대적으로 빠른 가류 속도와 높은 최대 토크값($T_{max}$), 우수한 기계적 물성을 보였고 MBTS는 상대적으로 중간 정도의 가황 시간과 낮은 $T_{max}$, 기계적 물성을 보였다. 마지막으로 CBS는 느린 가황 시간을 나타낸 반면 상대적으로 우수한 $T_{max}$와 기계적 물성을 나타냈다. 유사한 가황 특성 경향은 카본블랙이 충전된 천연고무 컴파운드에서도 찾아볼 수 있었다.

• Elastomers and Composites
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• 제58권3호
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• pp.128-135
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• 2023

To improve the adhesive strength of natural rubber (NR) for a seismic isolation damper, citraconic acid-g-NR (CCA-g-NR) was synthesized via the melt grafting of citraconic acid (CCA) onto NR using an azobisisnomerobutyronitrile (AIBN) initiator. Subsequently, the influence of CCA and AIBN concentrations on the graft ratio G/R (%) and graft efficiency G/E (%) of the CCA-g-NR was investigated. The optimum CCA and AIBN concentrations required to achieve the desired G/R (3.49%) and G/E (49.8%) were found to be 7 phr and 0.13 phr, respectively. Additionally, we studied the influence of CCA-g-NR concentration on the mechanical properties (tensile strength, elongation at break, and modulus at 300%), adhesive strength, and cure characteristics of the rubber compound in the seismic isolation damper. As the concentration of CCA-g-NR increased, the elongation at break and adhesive strength of the compound increased, whereas its tensile strength and modulus at 300% decreased. Moreover, as the concentration increased, the maximum torque decreased and the scorch time was delayed to obtain an optimal vulcanization time.

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

• 폴리머
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• 제36권5호
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• pp.637-642
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• 2012

실리카로 충전된 SBR(styrene butadiene rubber)/BR(butadiene rubber) 합성고무 복합소재에 대해서 가공기기의 구조가 실리카 분산에 미치는 영향을 파악하기 위해 주사전자 현미경(SEM-scanning electron microscope)을 이용하여 컴파운드의 모폴로지를 관찰하였다. Internal mixer 내에서 intermeshing rotor와 tangential rotor에 의해 배합된 컴파운드를 비교한 결과, intermeshing rotor에 의해 가공되었을 경우 실리카 입자가 더 고르게 분산 및 분포되었음을 관찰하였다. Rotor의 geometry 차이에 의해 intermeshing rotor가 tangential rotor보다 더 큰 전단력(shear)을 컴파운드에 전달하여 실리카 입자를 효과적으로 분산 및 분배시킨 것으로 판단된다.

• 폴리머
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• 제39권2호
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• pp.240-246
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• 2015

양기능성 실란 커플링제인 bis(triethoxysilylpropyl)tetrasulfide(TESPT)가 실리카/천연고무 복합소재 내에서 실리카의 hydroxy기와 고무 계면간에 화학적 결합반응을 하여 실리카-실란-고무간의 3차원 사슬구조를 형성한 것을 열분해 가스 크로마토그래피 질량분석기(Py-GC/MS)와 주사전자현미경(SEM)을 통해 관찰하였다. TESPT의 첨가로 배합물 내의 황 함유율이 증가하여 스코치 시간($t_{10}$)은 감소하고, TESPT 내 sulfur donor 역할을 하는 황이 활성화제 및 촉진제와의 복합반응으로 가교반응이 지속적으로 이루어짐에 따라서 가교속도지수(CRI)의 값이 감소하였다. 또한 TESPT가 첨가된 컴파운드는 첨가되지 않은 컴파운드에 비해 가공성 및 기계적 물성이 향상되었다. 결과적으로, 실리카로 충전된 천연고무 복합소재에 실란 커플링제(TESPT)가 첨가되어 화학반응으로 실리카-실란-고무간의 3차원 사슬구조가 형성됨을 관찰하였고 이에 따라 가교밀도가 증가하여 복합소재의 물성 증가에 기여함을 보여주었다.

• Elastomers and Composites
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• 제34권2호
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• pp.156-176
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• 1999

Rubber chemicals such as accelerators, antidegradants, vulcanizing agents, processing agents and retarders are very important to the production and protection of tires and rubber goods. The use of accelerators and antidegradants are evaluated in various tire components. This paper will focus on how to vulcanize tires economically and maintain the physical properties of each tire component without severe degradation due to oxygen, heat and ozone. Also, new non-nitrosoamine accelerators and non-staining antiozonants will be discussed. Lastly, the future requirements of antidegradants and accelerators in the tire industry will be reviewed. Tires have been vulcanized with Sulfenamides as primary accelerators and either Guamdine's or Thiurams as secondary accelerators to achieve proper properties at service conditions. However, interior components such as the carcass can be vulcanized with Thiazoles as a primary accelerator to cure faster than the external components. Using the combination of Sulfenamide with secondary accelerators in a tire tread compound and the combination of a Thiazole and Guanidine in a carcass compound will be presented with performance data. Uniroyal Chemical and another Rubber Chemical Manufacturer have developed, "Tetrabenzyl Thiuram Disulfide," (TBzTD) as a non-Nitrosoamine accelerator, which could replace Nitrosoamine generating Thiurams. This new accelerator has been evaluated in a tread compound as a secondary accelerator. Also, Flexsys has developed N-t-butyl-2-benzothiazole Sulfenamide (TBSI) as a non-Nitrosoamine accelerator which could replace 2-(Morpholinothio) -benzothiazole (MBS), a scorch delayed Sulfendamide accelerator. TBSI has been evaluated in a Natural Rubber (NR) belt skim compound vs. MBS. An optimum low rolling resistant cure system has been developed in a NR tread with Dithiomorpholine (DTDM). Also, future requirements for developing accelerators will be discussed such as the replacement of DTDM and other stable crosslink systems. Antidegradants are divided into two different types for use in tire compounds. Internal tire compounds such as apex, carcass, liner, wire breaker, cushion, base tread and bead compounds are protected by antioxidants against degradation from oxygen and heat due to mechanical shear. The external components such as sidewall, chafer and cap tread com-pounds are protected from ozone by antiozonants and waxes. Various kinds of staining and non-staining antioxidants have been evaluated in a tire carcass compound. Also, various para-phenylene diamine antiozonants have been evaluated in a tire sidewall compound to achieve the improved lifetime of the tire. New non-staining antiozonants such as 2, 4, 6-tris-(N-1, 4-dimethylpentyl-p-phenylene diamine) 1, 3, 5 Trizine (D-37) and un-saturated Acetal (AFS) will be discussed in the tire sidewall to achieve better appearance. The future requirements of antidegradants will be presented to improve tire performance such as durability, better appearance and longer lasting tires.