一种新型耐热可溶聚酰亚胺的制备及性质

成功合成带有三苯胺和吡喃环结构的新型功能性二胺4-(2-二氢吡喃)氧]-4’,4"-二氨基三苯胺(THP)。使用此单体与4,4′-二氨基二苯醚(ODA)和4,4′-(六氟异丙烯)二酞酸酐(6FDA)共聚,利用两步化学酰胺化法,制备了共聚物的组成配比不同的3种聚酰亚胺(PI)。使用NMR、FT-IR、DSC、UV-Vis等测试手段对单体和PI进行了结构表征和各项性能测试。研究了其溶解性能、耐热性能、透光性能和取向性能。结果表明3种PI均可溶于NMP、DMF等极性溶剂,同时在THF、DCM等低沸点溶剂中也具有较好的溶解性。PI的玻璃化转变温度在270℃以上,在500~800nm区域透过率在80%以上,液晶分子的预倾角随THP的增加而增大,可达2.3°,且具有均一的取向效果。

Synthesis and properties of novel heat-resistant,soluble polyimide

The diamine 4-(((tetrahydro-2H-pyran-2-yl)oxy)methyl)-4', 4″-diaminotriphenylamine (THP) containing triphenylamine group and pyran ring was successfully prepared. A series of polyimides (PIs) were synthesized with the copolymerization of THP, 4, 4'-Oxydianiline (ODA), 4, 4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) by chemical imidization. The structures and properties of the PIs were characterized by NMR, FT-IR, DSC, and UV-Vis etc. It was found that all PIs were soluble in polar solvents, such as N-methylpyrrolidone (NMP) and N, N-dimethylformamide (DMF) and even soluble in some common organic solvent with low boiling point such as Tetrahydrofuran (THF) and Trichloromethane (DCM). The glass transition temperature (T_g) of the PIs was above 270℃, and their transmittance in 500~800 nm wavelengths was more than 80%. It can be observed under POM that the liquid crystal could be aligned uniformly and a pretilt angle of about 2.3° can be obtained by using the PI films as liquid crystal alignment layer.