• Proceedings of the KAIS Fall Conference
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• 2000.10a
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• pp.65-68
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• 2000

긴 사슬의 알킬기를 가진 4차 암모늄염으로서 다수의 하이드록시기(OH)가 있는 대전방지 단량체(Ultramer 5212)를 합성하여 폴리아이소시아네이트 및 여러 종류의 폴리올과 반응하여 대전방지 코팅액을 배합하였다. 대전방지 단량체의 첨가량은 배합시 사용한 폴리올의 양을 기준으로 무게비(wt%)로 5부터 30 %까지 변화하였다. 열경화 실험은 VET 필름을 사용하여 경화온도 80와 160℃에서 수행하였다. 코팅된 PET 필름의 표면저항은 대전방지 단량체가 무게비로 10 % 첨가될 매까지 감소하였으나 첨가량이 10 %이상이 되었을 때는 오히려 약간 증가하였다. 코팅액 베합시 혼합용매는 코팅액 점도에 큰 영향을 주었으며 코팅액의 점도가 클수록 코팅표면의 투명도는 좋지 않았고 메틸에틸키톤(MEK)이 혼합용매로 가장 적절하다는 것을 알 수 있었다. 코팅액 배합조건 중 폴리올과 폴리아이소시아네이트 의 비율은 몰비로 1: 1일 때가 가장 좋았으며 반응성 대전방지제의 내수성은 일반 첨가형 대전방지제보다 월등히 우수함을 알 수 있었다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.6
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• pp.39-44
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• 2005

Due to mismatch of thermal expansion coefficients between aluminum sheet and glass/epoxy sheet, thermal residual stresses generally appear in the FML. These stresses will affect the yield and fatigue strength of the FML. The numerically determined residual stresses in the Fiber-Metal-Laminates(FML) have been compared to the residual stresses measured from the curvature and tensile test methods. These two experimental methods have been developed for assessing the influence of residual stress in FML. Post-stretching process has been applied to remove the thermal residual stress and reverse the stress distribution. After post-stretching process, the residual stress has been measured from experiments. The results obtained show that analytical and experimental data are well agreed. The thermal residual stress can be removed by post-stretching process and it will increase the yield strength of FML.

• Composites Research
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• v.15 no.2
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• pp.40-47
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• 2002

The di-functional epoxy resins, i.e., diglycidylether of bisphenol A(DGEBA) and diglycidylethere of bisphenol F(DGEBF) were initiated by cationic catalyst, i.e., benzylquinoxalinium hexafluoroantimonate(BQH) using electron-beam(EB) technique. And the effect of structure of DGEBA and DGEBF on thermal stabilities and cure behaviors was investigated. According to the experimental results, the decomposed activation energy based on Horowitz-Metzger method was higher in the case of DGEBA, but intergral procedural decomposition temperature(IPDT) of DGEBA was lower than DGEBF. This could be interpreted in terms of high crosslink density resulted from hydroxyl bond of DGEBF backbone. It was confirmed in increasing the hydroxyl band at $7000\;cm^{-1}$ and $5235\;cm^{-1}$ using near-infrared spectroscopy(NIRS).

• Composites Research
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• v.28 no.3
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• pp.99-103
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• 2015

This paper presents the cure kinetics studies on the cure reaction of thermosetting resin. Above all, change in degree of cure and specific heat capacity according to temperature are observed using DSC and MDSC. The results are analyzed by cure kinetics and specific heat capacity model. Glass transition temperature was also measured to apply to the specific heat capacity model. Model parameters were gained from the modeling result. As a result, behavior of specific heat capacity can be calculated mathematically.

• Journal of Adhesion and Interface
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• v.13 no.2
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• pp.53-57
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• 2012

A latent curing system was necessary for the anisotropic conducting film (ACF), and a fast reaction system was also necessary to fast production. In this study, the benzylsulfonium salts were synthesized and were used as latent curing initiators for epoxy resin. These benzylsulfonium compounds exhibited a long shelf life with epoxy resin. The curing behaviors of an epoxy resin with these sulfonium salts were investigated using differential scanning calorimetry (DSC), and the curing times were determined at $150^{\circ}C$ using an indentation method.

• Journal of the Korean Wood Science and Technology
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• v.38 no.4
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• pp.333-340
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• 2010

The Korean Dendropanax lacquer, made from a natural resinous sap from Dendropanax orbifera Lev., was used as a golden and transparent varnish for the traditional artifacts (armor uits, helmets, arrowheads, etc.) to make them be brilliant golden color. The cured film of the acquer has excellent protective properties such as weatherability, water resistance, and nticorrosive. But, one of disadvantages is that takes a long time and much energy to fulfill curing the lacquer. The chemical constituents of the lacquer contained conjugated diene compounds s the photopolymerizable monomers. These monomers easily polymerized in sunlight to form olden-colored, hard-coating films in a short time. Photooxidation may be one of the most mportant reactions in the chemistry of the lacquer. Although the Korean Dendropanax Lacquer hould be dried to a thoroughly dry stage to achieve optimal film properties, curing with elevated emperatures may be required for the protracted curing time at atmospheric temperature. So we ntended to accelerate the curing rate of the lacquer by dual curing of thermal and radiation uring. The effect of thermal initiator on the thermal curing reaction was evaluated by monitoring he changes in double bond peak with FT-IR. Then the curing rate of the lacquer blended with hermal initiator and photoinitiator together was measured during dual curing using a RPT with V spot curing machine. Thermal initiator not only accelerated the curing rate but also improved he physical property. And the curing rate of the Korean Dendropanax lacquer was improved by ual curing method of thermal and UV curing. According to these results, the application area of he Korean Dendropanax lacquer could be expanded to surface coatings for electronic devices uch as mobile phones or electronics.

• 대한치과보철학회:학술대회논문집
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• 1997.11a
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• pp.41-41
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• 1997

• 대한치주과학회:학술대회논문집
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• 2002.11a
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• pp.114-114
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• 2002

• Cement Symposium
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• s.35
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• pp.66-75
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• 2008

• 대한치주과학회:학술대회논문집
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• 2002.11a
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• pp.98-98
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• 2002