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비대칭 폴리이미드막의 제조 : effect of precipitation kinetic
전경용,김한성,한학수,조영일,장순호 한국공업화학회 1998 응용화학 Vol.2 No.2
The relationship between precipitation kinetic effect and morphologies of 6FDA-4,4'ODA polyimide membrane was investigated. The effect of the exchange rate of diffusion of DMAc-additive into the casting polymer solution is explored. It is found that if a nonsolvent contained a lager amount of DMAc is used, polymer solution system have a low nonsolvent diffusion coefficient and the less porous structure with a defect free skin. It can be predicted what membrane structure will be formed by observing the precipitation kinetics.
Hydroxyl 기를 갖은 용해성 폴리이미드의 합성 및 제조방법에 따른 특성변화
전경용,김한성,한학수,조영일,하순효 한국공업화학회 1998 응용화학 Vol.2 No.2
Aromatic soluble polyimide was synthesized from 2,2-bis(3-amino-4-hydroxyphenyl) hexafluoropropane and 4,4'-(hexafluoroisopropylidene)-bis-(phthalic anhydride) by one-step high temperature polycondensation and by two-step procedure using chemical imidization of poly(amic acid). Polyimide by chemical imidization was soluble in common organic solvent(acetone, NMP, DMSO, THF), in constrant polyimide synthesized with one-step method was soluble in amide solvent(NMP, DMAc). The difference of solubility was explained by esterification of hydroxyl group with dehydrating agents in chemical imidization.
전경용,김한성,한학수,조영일 ( Kyoung Yong Chun,Han Sung Kim,Hak Soo Han,Yung il Joe ) 한국공업화학회 1998 공업화학 Vol.9 No.2
용해성 PMDA/diamine/dianhydride 폴리이미드를 제조하여 특성을 고찰하고, 상용 알루미나 세라믹막내에 제조한 PMDA/diamine/dianhydride 용액을 코팅하여 기체투과특성을 알아보았다. Tg는 337∼358℃의 범위로 열적안정성은 우수함을 보였다. 용해성에 있어서는 NMP, DMAc, DMSO, THF, m-cresol의 극성 용매에 대해 대부분 좋은 결과를 보여 주었다. 알루미나막과 용해성 폴리이미드의 점착은 잘 이루어졌으며, 기체투과실험에 있어 6FDA를 포함한 폴리이미드의 경우 높은 투과도를 보였다. PDMA/1,3PDA/6FDA의 경우 질소투과도는 약 7.6×10^(-7) (㏖/㎡·Pa·s)의 값을 나타내었고, 질소에 대한 산소의 이상적 분리도, P(O₂/N₂)는 6.19였으며, P(H₂/N₂)의 경우는 약 70.0의 이상적 분리도를 보였다. The soluble polyimides(PMDA/diamine/dianhydride) were prepared and investigated. After coating the prepared PMDA/diamine/dianhydride solution into the commercial tubular alumina ceramic membranes, gas permeation characteristics was investigated T_g`s of the polyimides were in the range of 337∼358℃ and thermal stability was good. The polymer was soluble in NMP, DMAc, DMSO, THF, and m-cresol. The adhesion between the alumina membrane and the soluble polyimide was excellent. The soluble polyimide/alumina membranes containing 6FDA showed the highest permeability among others. The permeability of nitrogen of PMDA/1,3PDA/6FDA-alumina membrane was about 7.6×10^(-7) (㏖/㎡·Pa·s) in the gas permeation experiments. The ideal separation factor of O₂/N₂, and H₂/N₂ in PMDA/1,3PDA/6FDA-alumina membrane were 6.19, and 70.0, respectively.