• Geomechanics and Engineering
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• 제15권2호
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• pp.729-738
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• 2018

Soft clay soils due to their various geotechnical problems, stabilized with different additives. Traditional additives such as cement and lime will not able to increase the soil strength properties significantly. So, it seems necessary to use new additives for increasing strength parameters of soft clay soils significantly. Among the new additives, epoxy resins have excellent physical and mechanical properties, low shrinkage, excellent resistance to chemicals and corrosive materials, etc. So, in this research, epoxy resin used for stabilization of soft clay soils. For comprehensive study, three clay soil samples with different PI and various clay mineral types were studied. A series of uniaxial tests, SEM and XRD analysis conducted on the samples. The results show that using epoxy resin increases the strength parameters such as UCS, elastic modulus and material toughness about 100 to 500 times which the increase was dependent on the type of clay minerals type in the soil. Also, In addition to water conservation, the best efficiency in the weakest and most sensitive soils is the prominent results of stabilization by epoxy resin which can be used in different climatic zones, especially in hot and dry and equatorial climate which will be faced with water scarcity.

• Carbon letters
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• 제11권2호
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• pp.107-111
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• 2010

We prepared the amine epoxy adducts (AEA)/thin multiwalled carbon nanotubes (TWCNTs) composite particles using nonsolvent based methods including dry mechano-chemical bonding(MCB) process and supercritical fluid (SCF) process. The resulting TWCNTs/AEA composite particles have been used as curing agents for urethane modified bispheol A type epoxy resin. The thermal, thermomechanical properties of the epoxy resins cured with TWCNTs/AEA composite particles were measured by DMA and the dispersion of CNT was characterized by SEM. Because of high degree of CNT dispersion, thermal and mechanical properties of the epoxy resin cured with TWCNTs/AEA composite particles prepared by SCF process are better than those cured with mechano-chemically prepared TWCNTs/AEA composite particles.

• 공업화학
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• 제8권6호
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• pp.973-978
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• 1997

Diglycidyl ether of bisphenol A(DGEBA)수지에 castor oil(CO)로 혼합한 후 경화촉매인 tris(dimethylaminomethyl) phenol (DMP-30)로 반응시킨 에폭시의 강인성과 모폴로지를 관찰하였다. 개질제인 CO와 에폭시수지의 혼합물은 기존의 에폭시 개질제인 carboxyl terminated butadiene acrylonitrile(CTBN)보다 상용성이 좋았다. 경화온도와 CO의 양이 증가할수록 유리전이온도가 감소하였는데, CO/에폭시 경화물은 경화온도가 증가할수록 가교밀도가 감소하면서 연성구조를 갖게 되는 것으로 해석되었다. CO/에폭시 경화물은 경화온도 $40^{\circ}C$에서 CO의 양이 증가함에 따라 강인성이 약간 증가하였다. 경화온도가 증가와 CO의 양이 증가함에 따라 강인성이 증가하였다.

• International Journal of Ocean System Engineering
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• 제3권2호
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• pp.102-110
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• 2013

The purpose of this study was to improve the properties of epoxy resin using titanium oxide nanoparticles. The effects of particle weight fraction, dispersion agent, and curing agents with different molecular weights on the thermal and mechanical properties of titanium-oxide-reinforced epoxy resin were investigated. In addition, the effect of the particle dispersion condition on the mechanical properties of nanocomposites was studied. As a result, it was found that the glass transition temperature of film-shaped nanocomposites decreased with an in-crease in the nanoparticle content. Because nanoparticles interrupted the cross linkage between the epoxy resin and the amine curing agent, the cross-link density of the epoxy became lower and led to a decrease in $T_g$ in the nanocompo-sites. The tensile strength and modulus in film-shaped nanocomposites also increased with the particles content. But in the case of dog-bone-shaped nanocomposites, the values were not similar to the trend for the film-shaped nanocompo-sites. This was probably a result of the different nanoparticles dispersions in the epoxy resins resulting from the respective-thicknesses of the film and dog-bone-shaped samples.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1988년도 추계학술대회 논문집
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• pp.12-13
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• 1988

• 한국재료학회:학술대회논문집
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• 한국재료학회 2005년도 춘계학술발표대회 및 제8회 신소재 심포지엄 논문개요집
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• pp.164-164
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• 2005

• 한국조명전기설비학회지:조명전기설비
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• 제2권1호
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• pp.75-82
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• 1988

각종 전기설비용 절연재료로 주목받는 Epoxy는 경화제와의 가교반응으로 전기절연특성이 우수한 경화물질을 얻을 수 있으며, 경화제의 종류와 격자 형성에 형태에 따라 경화된 Epoxy의 특성이 결정된다. 본 연구는 Epoxy의 경화시 분위기의 온도를 변화시켜 격자형성의 진행형태를 변화시키고, 경화된 Epoxy의 제반특성을 조사하여 전기절연특성이 가장 우수하게 되는 경화온도를 얻고자 한다. Epoxy를 분위기 온도 $20~50[^{\circ}C]$사이에서 $5^[{\circ}C]$ 간격으로 변화하면서 경화시킨 결과, 분위기 온도 $30[^{\circ}C]$에서 경화된 Epoxy의 전기절연특성 및 기계적 강도가 가장 우수하다고 판명되었다.

• 방사선산업학회지
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• 제4권1호
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• pp.19-23
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• 2010

Vinyl ester (VE) resins, introduced in the late 1960s, have made large strides in reinforced plastics applications as adhesive and matrix materials on their appropriate mechanical performance characteristics in the glassy state. Generally, VE resins are a group of dimethacrylate resins based on bisphenol A type epoxy resin. They exhibit easy handling properties as well as good resistance to most chemical agents due to their mechanical and thermal properties. In this study, the effects of curing methods of vinyl ester resins on gel contents, flexural strength and dynamic mechanical properties were investigated. Thermal curing (room temperature, $80^{\circ}C$) and electron beam curing were used to crosslink a VE resin/styrene complex (65/35 wt%) with methyl ethyl ketone peroxide (MEKPO) as a catalyst and an 8 wt% cobalt naphthenate in styrene solution as a accelerator. For the samples, gel contents as well as flexural strength and dynamic mechanical properties were characterized and compared by soxhlet apparatus, universal testing machine (UTM) and dynamic mechanical analysis (DMA). As a result, the electron-cured VE resin was confirmed as a better condition than those for gel contents, flexural strength and dynamic mechanical properties, respectively.

• Composites Research
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• 제15권2호
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• pp.40-47
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• 2002

이관능성 에폭시 수지인 DGEBA와 DGEBF를 양이온 촉매인 BQH를 사용하여 전자선(electron-beam) 경화 기술에 의해 경화하였다. 그리고 수지의 구조적 차이가 열안정성과 경화동력학에 미치는 영향을 연구하였다. 실험적 결과에 의하면, Horowitz-Metzger 법에 의한 분해 활성화 에너지는 DGEBA의 경우가 높았지만 적분 열분해 온도(IPDT)는 DGEBA가 DGEBF 보다 낮았다. 이것은 DGEBF 주사슬의 수소 결합으로 인해 가교밀도가 높아졌기 때문인 것으로 사료되며, 근적외선 분광기(NIRS)를 사용하여 $5235\;cm^{-1}$와 $7000\;cm^{-1}$에서의 hydroxyl band의 증가로 확인하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.225-225
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• 2009

In this study, Nano and micro-filler mixture composites were fabricated by fixed value of $SiO_2$ nano-filler 0.4 [wt%] according to increase of $SiO_2$ micro-filler [wt%] from 1 to 10. Composites with a good dispersion of mixed $SiO_2$ Nano and micro-particles in the epoxy resins were prepared and experiments were performed to measure the dielectric breakdown strength properties with various temperature and thickness. The dielectric strength properties are compared and analyzed with respect to nano/micro-composites filled with $SiO_2$ fillers less than properties obtained for nanocomposites.