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고내열 POF용 클래딩 재료 제조(I) -Methyl Methacrylate/Fluoroalkyl Methacrylate 공중합체-
정민진,김영필,김진봉,이무성,진문영,박민,Jung, Min-Jin,Kim, Young-Fil,Kim, Jin-Bong,Lee, Moo-Sung,Jin, Moon-Young,Park, Min 한국섬유공학회 2003 한국섬유공학회지 Vol.40 No.4
The effect of the length of fluoroalkyl substituents on the refractive index (n) and glass transition temperature (T$_{g}$) of methyl methacrylate (MMA)-fluoroalkyl methacrylate (FAMA) copolymers (poly(MMA/FAMA)) was investigated. The copolymers were solution-polymerised in order to prepare cladding materials for plastic optical fiber (POF). The copolymer composition, T$_{g}$, and refractive index (n) of the copolymers were determined using $^1$H-NMR spectroscopy, differential scanning calorimeter, and prism coupler, respectively. As the length of fluoroalkyl units in FAMA and the content of FAMA in poly (MMA/FAMA) increased, the T$_{g}$ and n decreased monotonically. This indicates that although the copolymerization of MMA and FAMA is effective in controlling the n of cladding materials, the decrease in T$_{g}$, is inevitable. The interfacial instability between PMMA and MMA-trifluoroethyl methacrylate (TFEMA) copolymers, observed during annealing at 17$0^{\circ}C$, was greater at higher TFEMA contents. The observation was interpreted in terms of the solubility parameter concept combined with the Flory-Huggins interaction parameter.rameter.
Methylsilsesquioxane - dimethylsiloxane 공중합체의 졸 - 겔 합성
진문영,이정훈,홍석인,서태수,석상일 한국화학공학회 2001 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.39 No.2
저 유전(low-k) 반도체 층간 절연막 재료로 사용되는 MSSQ(mathylsilsesquioxane)의 취성을 개선하여 유연성을 부가하고자 dimethylsiloxane unit을 MSSQ에 0-20 ㏖% 도입한 공중체 합성이 시도되었다. MSSQ-dimethylsiloxane 공중체는 THF를 용매로 일정량의 MTCS(methyltrichlosilane)를 녹인 후 약 3 당량비의 물을 가한 후 가수분해하고, THF에 희석한 일정량의 DMDCS(dimethyldichlorosilane)를 서서히 첨가하여 고분자화하는 졸-겔 방법에 의해 합성되었다. 약 5시간 반응시킨 후 계속적인 중합 반응에 의한 겔화를 방지하기 위하여 반응 부산물이며, 촉매로 작용하는 염산을 물로 수세하여 제거하였다. 합성된 공중합체는 용매 제거 후 고체상의 분말로 얻어지지만, THF, 에탄올, MIBK 등 유기 용매에 우수한 용해성을 가지고 있었다. ¹H-NMR, ^(29)Si-NMR 및 FT-IR 분석으로부터 공중합체의 구조가 분석되었으며, 열중량 분석에 의해 열축합(curing)온도 및 내열성이 평가되었다. 합성된 공중합체를 500℃에서 1시간 열처리한 후 ^(29)Si-Solid NMR로 분석한 결과 dime-thylsiloxane에 의한 D 구조가 MSSQ에 안정하게 유지됨이 확인되었다. Dimethylsiloxane modified methylsilsesquioxane(MSSQ) copolymers considered as low K dielectric materials were tried to synthesized to improve the brittleness by MSSQ alone. MSSQ-dimethylsiloxane copolymers were prepared using sol-gel reaction after MTCS(methyltrichlorosilane) and DMDCS(dimethyldichlorosilane) were hydrolyzed by H₂O in THF solvent. The solid phase products, soluble in various organic solvents like THF, MIBK etc., were obtained by washing acid with deionized water, and the evaporation of toluene. The local structures for MSSQ and copolymers were analyzed by ¹H-NMR, ^(29)Si-NMR and FT-IR. The thermal behavior and curing temperature were determined by TGA, and the loss of the copolymers having siloxane bonds were almost constant above 400 ℃. It was observed from ^(29)Si-solid NMR that D skeletons copolymerized with MSSQ after heat-treatment at 500 ℃ for 1 h were still remained.