一种可溶性聚酰亚胺的合成及其膜性能

Study for Synthesis and Membrane Properties of A Soluble Polyimide

一种含三氟甲基的聚酰亚胺(PI),由二胺单体1,4-双(4-氨基-2-三氟甲基苯氧基)苯和二苯醚四酸二酐在间甲酚为溶剂的条件下,通过一步法聚合而成。PI在室温下能够溶于常用的有机溶剂,例如:N-甲基吡咯烷酮(NMP),N,N-二甲基乙酰胺(DMAc),N,N-二甲基甲酰胺(DMF),三氯甲烷和四氢呋喃(THF)。这种可溶性的PI可以通过静电纺的方法加工成柔性的纤维膜材料,并且通过调节纺丝液浓度及溶剂配比得到具有不同形貌结构的PI纤维膜。该聚合物具有优异的热稳定性,其玻璃化转变温度(t_g)为223℃,氮气气氛下5%的热失重温度为547℃,800℃下的热失重率为56%。实验还进一步对纤维膜的表面润湿性进行了研究,结果显示不同纤维形态结构的聚合物膜均表现出疏水性,其接触角在128°~136°。

The polyimide containing trifluoromethyl(PI) was prepared via one-step polycondensation by 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene and 4,4′-oxydiphthalic dianhydride in m-cresol. The obtained PI could be dissolved in a variety of organic solvents such as N-methyl-2-pyrrolidinone(NMP), N,N-dimethylacetamide(DMAc), N,N-dimethylformamide(DMF), chloroform and tetrahydrofuran(THF) at room temperature. The PI could be easily processed into flexible fiber membrane by electrospinning. Meanwhile, the different morphology PI fiber membrane could be prepared by adjusting the concentration and solvent proportioning of spinning solution. The polymer showed excellent thermal stability with glass-transition temperatures at 223 ℃, 5% weight loss temperatures at 547 ℃, and the weight residue more than 56% at 800 ℃ in nitrogen. Moreover, the surface wettability of PI electrospun membranes were characterized by contact angle measurement. The range of contact angles on the electrospun uniform PI fibers for water was 128°~136°.