• Elastomers and Composites
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• v.33 no.4
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• pp.281-289
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• 1998

Tensile properties including Young's modulus and tear strength were measured for four different rubber compounds; natural rubber(NR), styrene-butadiene copolymer(SBR), ethylene-propylene diene monomer (EPDM), and brominated isobutylene-p-methyl-styrene copolymer(BIMS) as a function of temperature and degree of cure. To see the effect of over cure, a measurement was made of the tensile strength and swelling behavior of the over-cured rubber compounds. Young's modulus, E, was found to have linear dependency on the degree of cure for all rubber compounds. EPDM and BIMS showed the highest and lowest slopes, respectively. The slope of NR and SBR lay between EPDM and BIMS. Tear strength, Gc, decreased in the order of NR>BIMS>SBR>EPDM. As the cure time was extended the degree of cure of NR and SBR decreased, while that of BIMS increased. EPDM showed little change in the degree of cure.

• Journal of the Korean Geotechnical Society
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• v.24 no.2
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• pp.87-97
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• 2008

Behaviors of cemented engineered soils, composed of rigid sand particle and soft rubber particle, are investigated under $K_o$ condition. The uncemented and cemented specimens are prepared with various sand volume fractions to estimate the effect of the cementation in mixtures. The vertical deformation and elastic wave velocities with vertical stress are measured. The bender elements and PZT sensors are used to measure elastic wave velocities. After cementation, the slope of vertical strain shows bilinear and is similar to that of uncemented specimen after decementation. Normalized vertical strains can be divided into capillary force, cementation, and decementation region. The first deflection of the shear wave in near field matches the first arrival of the primary wave. The elastic wave velocities dramatically increase due to cementation hardening under the fixed vertical stress, and are almost identical with additional stress. After decementation, the elastic wave velocities increase with increase in the vertical stress. The effect of cementation hinders the typical rubber-like, sand-like, and transition behaviors observed in uncemented specimens. Different mechanism can be expected in decementation of the rigid-soft particle mixtures due to the sand fraction. a shape change of individual particles in low sand fraction specimens; a fabric change between particles in high sand fraction specimens. This study suggests that behaviors of cemented engineered soils, composed of rigid-soft particles, are distinguished due to the cementation and decementation from those of uncemented specimens.

• Elastomers and Composites
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• v.43 no.3
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• pp.173-182
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• 2008

Rubber-pad forming process for materials such as metal in which portions of the die which act upon the material is composed of a natural or synthetic rubber or elastomer material. This makes the rubber pad forming process relatively cheap and flexible, high accuracy for small product series in particular. In this study, we carried out the physical test and finite element analysis of elastomer such as natural rubber and urethane for steel rack rube forming. The non-linear property of elastomer which are described as strain energy function are important parameter to design and evaluate of elastomer component. These are determined by material tests which are uni-axial tension and bi-axial tension. This study is concerned with simulation and investigation of the significant parameters associated with this process.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.10
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• pp.1163-1169
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• 2012

Rubber, a hyperelastic material, is the main material used in tires. During the operation of a car, the tire receives various types of loads. The accumulation of strain energy due to such loads induces tire failure. Generally, because rubber materials used for tires have stress softening characteristics, unlike metals, test methods used for metals cannot be applied to rubber. Therefore, in this study, for the evaluation of the fatigue properties of two types of specimens that have different material components, a tensile test and a fatigue test according to the extended strain range dissimilar to ASTM D4482 are performed, and fatigue life equations are proposed based on the test results.

• Composites Research
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• v.24 no.6
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• pp.18-24
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• 2011

The effect of surface treatments with the atmospheric pressure flame plasma (APFP) and epoxy silane (ES) is experimentally investigated to yield the best mechanical properties of silica ($V_f=40%$) reinforced elastomeric composites. The tensile strength of the composites is increased significantly with decrease the mean diameter. When the diameter is $2.2{\mu}m$, that of the composite is increased about 1.4 times compared to the matrix (2.52 MPa). Also, the tensile strength of silica reinforced composites with APFP and ES treated is increased 8.8~13.3%, 9.9~12.5%, respectively. When the diameter is $26.6{\mu}m$, the tensile modulus of the composite is increased about 2 times compared to the matrix (0.88MPa), and the tensile modulus of silica reinforced composites with APFP and ES treated is increased 15.6~22.8%, 21.1~5.8%, respectively. Conventional silane coupling agent treatment have a few disadvantages because of using organic solvents. However APFP treatment is a fast, economic and eco-friendly method to improve the mechanical properties.

• Elastomers and Composites
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• v.14 no.4
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• pp.260-263
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• 1979

티오디에탄올을 기본(基本)으로 하는 신합성(新合成)고무의 사용온도범위(使用溫度範圍)는 $-65^{\circ}C$에서 $150^{\circ}C$이며 표준연료(標準燃料) C와 gasohol을 포함(包含)한 각종(各種) 자동차용(自動車用) 오일에 대하여 우수(優秀)한 내유성(耐油性)을 보였고, 이 외(外)에 자연(自然)에서 널리 발생(發生)되는 황화수소(黃化水素)가스에 대(對)하여서도 우수(優秀)한 내(耐)가스성(性)을 보였다. 이 TDE 탄성체(彈性體)의 배합(配合)은 종래(從來)의 2본(本) 로울러 또는 밀폐식(密閉式) 혼합기(混合機)로 혼연(混練)할 수 있으며, compression, 사출(射出), 프레스 등으로 가황(加黃) 또는 유출(押出)이 가능하다. American Cyanamid Co에서는 TDE탄성체(彈性體)를 이용(利用)한 응용개발(應用開發)에 있으며 파일롯규모(親模)의 생산체제(生産體制)를 시도(試圖)할 것으로 알려져 있다. 이것이 시판(市販)되면 상품명(商品名)으로 Cymax라 명명(命名)될 것이며, 아민계(系곤) 가황제(加黃劑)인 DPP의 상품명(商品名)도 Cymax Curative P로 시판(市販)하게 될 것이다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.742-748
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• 2003

As for marine propulsion shafting system using 4 stroke diesel engine, it is common to apply reduction gear box between diesel engine and shafting with a view of increasing mechanical efficiency, which inevitably require elastic coupling due to avoid chattering and hammering inside of gear box. In this study, optimum method of rectifying propulsion shafting system in case of 750ton fishing vessel specially in a view of torsional vibration, is theoretically studied. After exchange of diesel engine and gear box, analysis result of torsional vibration get worse and so some countermeasure are needed. The elastic coupling is modified from present block type rubber coupling showing relatively high torsional stiffness to rubber coupling with two series elements directly connected. The vibration measurement using two laser torsion meters was done during sea trial, whose results are compared to those of calculation and verified.

• Applied Chemistry for Engineering
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• v.20 no.4
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• pp.375-380
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• 2009

Polyepichlorohydrin rubber was treated with sodium azide (Na$N_3$) to replace its chlorine by azide ($N_3$). Then, the azidated polyepichlorohydrin rubber (Az-PECH) was blended with thermoplastic styrene-acrylonitrile copolymer with the rubber/plastic ratio of 80/20, 70/30 and 60/40 (wt/wt). The miscibility, mechanical and dynamic mechanical properties as well as elastic recovery properties of the blends were evaluated by DMA (Dynamic Mechanical Analyzer) and tensile tests. When azidation level in azidated PECH was upto 50%, the blends exhibited excellent miscibility, manifested by a single $T_g$, and fairly good elastic recovery. When azidation level was 75%, the blends showed phase separation. The miscible Az-PECH/SAN blends exhibited typical thermoplastic elastomer like properties, ie. melt processibility and high extensibility as well as good elastic recovery rate. It was also observed from combustion test that higher energy is released with the increase in the azidation level of the Az-PECH in the blends.

• Elastomers and Composites
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• v.33 no.5
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• pp.315-323
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• 1998

The purpose of this study was to investigate the crosslinking density and reinforcement of rubber compounds with various carbon black loadings, cure systems and cure temperatures. Bound rubber content increased with volume fraction of carbon black in rubber compounds, but total crosslinking density decreased with increasing the bound rubber content. Rate constant of cure reaction was changed significantly by cure system and cure temperature, especially it showed strong dependence on the cure temperature. High activation energys of cure reaction were shown in the rubber compound with high loading of carbon black under EC system and in the rubber compound with low loading of carbon black under CC system. High total crosslinking density of vulcanized compounds appeared in the rubber compound with low loading of carbon black and CC system among cure systems. Typical change of total crosslinking density by EC system was not shown. The highest elastic constant by Mooney-Rivlin equation was shown in the rubber compound with low loading of carbon black and SEC system. Modulus increased as increasing the loading of carbon black in the rubber compounds and showed the order of SEC, CC, and EC system for cure system.

• Elastomers and Composites
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• v.33 no.4
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• pp.290-296
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• 1998

Recycling of waste tire has been limited and very simple, few applications have been observed. This study introduces a new elastic and permeable pavement made of scrap tire. Experimental results showed that key factors affecting the compressive strength were the size of scrap tire, size of aggregate, amounts and property of binder. Also, the water permeability depended on the size of aggregate and scrap tire. The compressive strength and water permeability of the samples were 1.4 and 116 times higher than those of the conventional porous cement concrete, respectively.