Fabrication of 6FDA-HFBAPP Polyimide Asymmetric Hollow Fiber Membranes and Their CO2/CH4 Separation Properties

作     者：Cong-Jun Gan Xiao-Chen Xu Xue-Wei Jiang Feng Gan Jie Dong Xin Zhao Qing-Hua Zhang Cong-Jun Gan;Xiao-Chen Xu;Xue-Wei Jiang;Feng Gan;Jie Dong;Xin Zhao;Qing-Hua Zhang

作者机构：State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and Engineering Donghua University 

出 版 物：《Chinese Journal of Polymer Science》 (高分子科学（英文版）)

年 卷 期：2019年第37卷第8期

页      面：815-826页

核心收录：

学科分类：07[理学] 0703[理学-化学] 

基　　金：financially supported by the National Natural Science Foundation of China (No. 21774019) Program of Shanghai Academic Research Leader (No. 18XD1400100) Natural Science Foundation of Shanghai (No. 18ZR1400600) Fundamental Research Funds for the Central Universities (No. 2232017A-01) Shanghai Science and Technology Commission "Yangfan" Program (No. 17YF1400500) Shanghai Science and Technology Innovation Action Plan (No. 16JC1403600) 

主　　题：Polyimide Gas separation Preparation conditions Membrane structure Permeability 

摘      要：In this work, poly(amide acid) solution, the precursor of polyimide, was synthesized by the reaction of 4,4′-(hexafluoroisopropylidene)diphthalicanhydride and 2,2-bis[4-(4-aminophenoxy)phenyl]-hexafluoropropanane in the solvent of N-methyl-2-pyrrolidone(NMP) and tetrahydrofuran(THF). Then, hollow fiber membranes for high flux gas separation were prepared by dry-jet wet spinning using the precursor solution of poly(amide acid) as the spinning dope and a subsequent imidization process. Silicone rubber was further coated outside the obtained hollow fiber membranes to repair the defects on the denser layer. The effects of internal, external coagulation bath ratios with air gap, and coating solution concentrations on the morphologies, structures, and separation performance of the membranes were studied. Results showed that the sponge-like support layer was formed when the content of NMP was increased from 50% to 90% in the internal coagulation bath. The outer surface of the membrane became denser when the water content in the external coagulation bath increased from 40% to 100%, and the separation coefficient of CO2/CH4 increased by 2 times. This value could reach up to 1.4 when the air gap was 6 cm. With tuning the mass fraction of silicone rubber as 5%, hollow fiber composite membranes with uniform coating layer and an improved separation coefficient of 5.4 could be obtained.