聚脲酰亚胺膜的制备、性能和液晶分子定向功能的表征  

Preparation, Properties and Alignment Function of Polyureas-imide Film

作　　者：王铭钧[1] 杨晓慧[1] 姚洪喜[1] 

机构地区：[1]上海交通大学化学化工学院,上海200240

出　　处：《绝缘材料》2014年第5期30-35,共6页Insulating Materials

摘　　要：以均苯四甲酸酐（PMDA）、4,4’-二氨基二苯醚（ODA）和四甲基-双（γ-氨丙基）二硅氧烷（APDS）合成了氨端基聚酰胺酸预聚体，然后分别用甲苯二异氰酸酯（TDI）和二苯甲烷二异氰酸酯（MDI）扩链制得聚脲酰胺酸，经亚胺化制备了两种聚脲酰亚胺POAU（T）和POAU（M）。通过TGA和IR研究聚脲酰亚胺的热稳定性，测试聚脲酰亚胺在频率为0.1-105Hz和温度50-300℃的介电常数（ε）和介质损耗（tanδ）。结果表明：聚脲酰亚胺分子链段中存在两个转变温度Tg，脲基链段的Tg为244℃（POAU（T））及243℃（POAU（M）），酰亚胺环链段的Tg温度为329℃（POAU（T））及331℃（POAU（M））。预倾角测定（TBA）结果表明该聚脲酰亚胺是一种良好的液晶分子定向膜材料。Polyimide acid prepolymers were synthesized from pyromellitic dianhydride（PMDA）, 4,4′-diami-no diphenyl ether（ODA）, and tetramethyl-bis-（γ-aminopropyl） disiloxane（APDS）, and the polyureas-imide acids were prepared by chain extension reaction with toluene diisocyanate（TDI） and methylene diphenyl diisocyanate（MDI） respectively, then two kinds of polyureas-imide POAU（T） and POAU（M） were prepared by imidization. The thermal stability of the polyureas-imides was studied by IR and TGA, and the dielec-tric constant and dielectric dissipation factor at 0.1-105 Hz and 50-300℃ were tested. The results show that the polyureas-imide molecule exist two glass transition temperature （Tg）, and the Tg of HN-CO-NH group is 244℃（POAU（T）） and 243℃（POAU（M））, the Tg of imide ring is 329℃（POAU（T）） and 331℃（POAU（M））. The pretilt angle test result shows that the polyureas-imide is a good alignment film materi-al for liquid crystal molecules.

关 键 词：聚脲酰亚胺 热稳定性 微相分离结构 介电性能 预倾角 

分 类 号：TM215.3[一般工业技术—材料科学与工程]