• Elastomers and Composites
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• v.43 no.2
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• pp.113-123
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• 2008

Epoxy resins are thermoset polymers that exhibit good adhesion, creep resistance, heat resistance, and chemical resistance. These polymers, however, give poor resistance to crack propagation and low impact strength. In this study, epoxy/carboxyl-terminated butadiene acrylonitrile (CTBN) and epoxy/amine-terminated butadiene acrylonitrile (ATBN) composites were prepared with different ratio of CTBN and ATBN to improve low impact strength of epoxy resin. The impact strength of epoxy/elastomeric composites shows high values with increasting nonpolar surface free energy while the tensile strength and the glass transition are decreased. The highest surface free energy, impact strength observed when 15 phr CTBN and 15 phr ATBN added, respectively. It can be concluded that as liquid rubber to improve impact strength of epoxy resin, ATBN is more preferable to CTBN.

• Applied Chemistry for Engineering
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• v.22 no.2
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• pp.149-154
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• 2011

In order to explore properties of various rubber compounds after thermal aging under the condition similar to the operating environment of a fuel cell-stack, heat resistance and compression set of those compounds were investigated for a long term operation in $H_2SO_4$, $H_2O$, and LLC (ethylene glycol : $H_2O=50:50$) solution. It was assumed that aging Acrylonitrile butadiene rubber (NBR) and Elthylene Propylene diene rubber (EDPM) compound in the solution resulted in discoloration as time passed. It was also found that hydrolysis was developed on the Silicone rubber (VMQ) compound intentionally aged under acidic condition by means of TGA, SEM, and EDS analysis.

• Applied Chemistry for Engineering
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• v.7 no.4
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• pp.633-638
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• 1996

The phenyl modified silicone polymer, 1,1-diphenyl-1-methyl-7-hydroxydodecamethylheptasiloxysilane, was synthesized to prepare the silicone polymer with good cold-proof and heart-proof properties. From the TGA analysis in the range of $100{\sim}800^{\circ}C$, the phenyl modified silicone polymer had good thermal properties than polydimethylsiloxane. And furthermore fluidity was maintained even below $0^{\circ}C$. Also, the silicone rubber blended with the phenyl modified silicone polymer had better mechanical properties than the silicone rubber.

• Elastomers and Composites
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• v.13 no.3
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• pp.197-206
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• 1978

반응속도면(反應速度面)에서의 동력학적(動力學的) 연구결과(硏究結果)에 의(依)하면 2-메르캅토벤쪼티아졸(MBT)은 N-t-부틸-벤쪼티아졸썰펜아미드(BBTS) 또는 2-(4-몰폴리노티오) 벤쪼티아졸(OBTS)과 같은 가황촉진제(加黃促進劑)들 보다는 N-(싸이클로헥실티오)프탈이미드(CPT)가 훨신 더 빨리 반응(反應)한다는 사실(事實)을 탐지(探知)하였다. 또한 우수(優秀)한 가황지연제(加黃遲延劑)는 MBT와 급속(急速)히 반응(反應)하여야 하지마는 실소(室素)와 황(黃)과의 화학결합(化學結合)이 너무 약(弱)하여 내열안정성(耐熱安定性)이 없음으로 아무리 MBT와 빠른 속도(速度)로 반응(反應)하여도 좋은 가황(加黃)지연제가 될 수는 없다. 예를들면 N-(싸이클로헥실티오-O-벤쪼의 썰펜이미드(CTBS))는 CTP보다 더 빨리 MBT와 반응(反應)하지만 열안정성(熱安定性)이 부족(不足)하여 가황(加黃)지연제로서는 CTB 보다 좋지 못하다.

• Textile Coloration and Finishing
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• v.31 no.2
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• pp.107-117
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• 2019

In case of pure rubber materials, the initial quality of the rubber materials would be excellent, however, the durability against external impact might be poor. In order to overcome the relatively low durability, textile cord could be employed with silicone rubber. We have studied the improvement of heat-resistant adhesion properties of silicone adhesives between silicone rubber and PET fibers by applying various conditions including dip solution recipe. The silicone rubber used was a platinum catalyst curing type and platinum catalyst type silicone adhesive was used as an adhesive to obtain an optimum adhesive force. Furthermore, the bonding mechanism between silicone and PET fiber was established.

• Journal of Adhesion and Interface
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• v.22 no.4
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• pp.118-127
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• 2021

In this study, the mechanical properties of vulcanized rubber were evaluated through compounding by controlling filler content to improve the mechanical properties of NBR rubber. Aramid and glass fibers with excellent heat resistance were used as fillers, and ceramics were additionally used in anticipation of a complementary effect, and as for the ceramic materials, needle-shaped and plate-shaped ceramics were used. Each filler was used in an amount of 5.0, 10.0, 15.0, and 20.0 phr in order to investigate the basic properties according to the amount of filler. To confirm the complementary effect through ceramic application, each 10.0 phr fiber and ceramic were mixed with 1:1 ratio to evaluate mechanical properties. As a result, it was confirmed that the decreasing ratio of tensile strength after heat aging was small in the order of aramid fiber, acicular ceramic, glass fiber, and plate ceramic in the case of applying the filler alone. In addition, the mechanical characteristics of vulcanized rubber using composite filler based on fibers and ceramics were evaluated, and it was confirmed that the composite filler had a complementary effect on thermal aging.

• Journal of the Korean Society for Nondestructive Testing
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• v.26 no.5
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• pp.343-352
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• 2006

In the present paper, the nondestructive test method was suggest to establish the bonding status of a motor case assembly composed of a steel motor case, adiabatic rubber layer and an ablative composite tube with strain data, AE(acoustic emission) signals and UT(ultrasonic test) data. And, finite element analysis was conducted to verify quantitatively the bonding status of motor case assembly under inner pressure loading. The bonding status could be judged whether the bonding status is perfect or contact condition by the data correlation study with AE signals and strain data measured from air pressure test. And, to classify the bonding status of motor case and rubber layer among bonding layers, UT method was also applied. From this study, the bonding status could be classified and detected into fourth types for all bonding layers as follows: (1) initial un-bonding, (2) perfect do-bonding during an air pressure test, (3) partially de-bonding during an air pressure test, and (4) perfect bonding.

• Elastomers and Composites
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• v.45 no.3
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• pp.212-216
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• 2010

The materials of the lithium ion battery gasket require chemical resistance to the electrolyte, electrical insulating, compression set, anti-contamination and heat resistance. To estimate suitability for rubber which has better performance to compression set than PFA, each compound were made with various rubbers, such as EPDM, NBR, FKM, FVMQ, VMQ and we checked the characteristics of each compound. Samples from each compound was deposited in Propylene Carbonate and tested for changing of Hardness and Volume during 1,000 hr with $80^{\circ}C$. EPDM and VMQ showed good performance to chemical resistance to the electrolyte, and also we could get the values over $10^{10}{\Omega}cm$ on volume resistance basis in electrical insulating. EPDM and VMQ were judged as the most suitable material.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.7
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• pp.1661-1667
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• 2009

Post-cure characteristics of a silicone rubber material which is widely used for a LCD lamp holder were investigated using thermogravimetric analysis (TGA). Research was especially focussed on searching for the optimum post-cure conditions in relation to the practical operation environments. The results showed that incipient volatile temperature(Ti) during the process was considered as the most important factor and, thereby, post-curing for 2hrs at $250^{\circ}C$seemed to be a reasonable condition in the practical view-point. Arrhenius plot of shift factors which were empirically determined from the time-temperature-superposition-principle showed good linearity, exhibiting the post-cure mechanism might be proceeded through single mechanism with activation energy of 108.25kJ/mol.

• Elastomers and Composites
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• v.22 no.4
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• pp.324-332
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• 1987

The thermal degradation of the homopolymer poly(methyl methacrylate) (PMMA) and flame-retardant tetrabrormobisphenol-A(TBBA) as well as of their blends were carried out using the thermogravimetric method in the stream of nitrogen gas with 60ml/min at various heating rate from 1 to $20^{\circ}C/min$. Friedman and Ozawa mathematical methods were used to obtain the value of activation energy.