烷基取代环丁烷型聚酰亚胺液晶取向膜的制备及性能  

Preparation and properties of polyimide alignment films containing alkyl-substituted cyclobutane ring

作　　者：职欣心 魏鑫莹 祁浩然 吴昊 张燕 刘金刚[1] 刘艳改[1] ZHI Xinxin;WEI Xinying;QI Haoran;WU Hao;ZHANG Yan;LIU Jingang;LIU Yangai(School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China)

机构地区：[1]中国地质大学(北京)材料科学与工程学院,北京100083

出　　处：《功能材料》2020年第12期12184-12191,共8页Journal of Functional Materials

基　　金：山东省重点研发计划资助项目(2019JZZY020235)。

摘　　要：以甲基顺丁烯二酸酐(MMA)为原料,以乙酸乙酯为溶剂,利用紫外光(波长:365 nm)辐照环加成工艺制备了1,3-二甲基-1,2,3,4-环丁烷四酸二酐(MCBDA)。采用MCBDA分别与柔性芳香族二胺单体,包括1,3-双(3-氨基苯氧基)苯(133APB)和2,2′-双[(4-氨基苯氧基)苯]六氟丙烷(BDAF)通过两步化学亚胺化工艺制备了两种有机可溶性聚酰亚胺(PI)树脂,PI-1(MCBDA-133APB)与PI-2(MCBDA-BDAF)。两种树脂在极性非质子性溶剂,如N-甲基-2-吡咯烷酮(NMP)中具有良好的溶解性。采用PI/NMP溶液成功制备了无色透明PI薄膜。系统研究了脂环结构对PI薄膜耐热性能以及光学性能的影响。研究结果表明,PI薄膜具有良好的耐热稳定性。PI-1与PI-2薄膜的起始热分解温度(T5%)分别为436.0与450.9℃。同时,PI薄膜在可见光区(400~700 nm)具有优良的光学透明性。PI-1与PI-2薄膜在450 nm波长处的透光率分别为76.0%和86.0%,薄膜的黄度指数(b*)分别为2.06和1.64,浊度均低于1.0%。采用PI-1与PI-2溶液作为液晶分子取向膜装配了液晶盒。测试结果显示,PI-1与PI-2取向膜对液晶分子均具有良好的取向效果,预倾角分别为1.3°和4.4°。PI-1装配的液晶盒的电压保持率超过98.00%。1,3-Dimethyl^-1,2,3,4-cyclobutanetetracarboxylic dianhydride(MCBDA)was prepared by the ultraviolet(wavelength of 365 nm)irradiation photo-addition procedure with methyl maleic anhydride(MMA)as raw material and ethyl acetate as the solvent.Two organo-soluble polyimide(PI)resins,PI-1(MCBDA-133APB)and PI-2(MCBDA-BDAF)were prepared via a two-step chemical imidization procedure by the polymerization of MCBDA and aromatic diamine monomers,including 1,3-bis(3-aminophenoxy)benzene(133APB)and 2,2′-bis[(4-aminophenoxy)benzene]hexafluoropropane(BDAF),respectively.The MCBDA-PI resins showed good solubility in polar aprotic solvents,such as N-methyl-2-pyrrolidone(NMP).Colorless and transparent PI films were successfully prepared by the PI/NMP solution.Effects of the alicyclic structure on the heat resistance and optical properties of PI films were studied.The measurement results indicated that the MCBDA-PI films showed good thermal stability with the thermal decomposition temperatures(T5%)of 436.0℃for PI-1 and 450.9℃for PI-2,respectively.Meanwhile,the MCBDA-PI films exhibited excellent optical transparency in the visible region(400-700 nm).The transmittance of the PI-1 and PI-2 films at the wavelength of 400 nm was 76.0%and 86.0%,respectively.The yellowness index(b*)of the PI films was 2.06 and 1.64 for PI-1 and Pi-2,respectively.The haze values were all lower than 1.0%.The liquid crystal minicells were successfully assembled with PI-1 and PI-2 as the alignment films for liquid crystal molecules.The test results indicated that the rubbed MCBDA-PI alignment films could induce a pretilt angle of 1.3°and 4.4°for PI-1 and PI-2,respectively.The liquid crystal minicell fabricated with PI-1 alignment film showed a high voltage holding ratio over 98.00%.

关 键 词：聚酰亚胺 环丁烷 光学透明性 热稳定性 液晶取向膜 

分 类 号：TN141.9[电子电信—物理电子学] TQ323.7[化学工程—合成树脂塑料工业]