磺化自聚微孔聚酰亚胺的制备及磺化度对其气体分离性能的影响  

Preparation of sulfonated intrinsic microporous polyimide and the effect of sulfonation degree on their gas separation properties

作　　者：刘清潭 储家琛 李建新 马小华 LIU Qingtan;CHU Jiachen;LI Jiancin;MA Xiaohua(State Key Laboratory of Membrane Separation and Membrane Process,School of Material Science and Engineering,Tiangong University,Tianjin 300387,China)

机构地区：[1]天津工业大学材料科学与工程学院省部共建分离膜与膜过程国家重点实验室,天津300387

出　　处：《膜科学与技术》2023年第3期1-7,共7页Membrane Science and Technology

基　　金：国家自然科学基金项目(22078245);榆林学院-大连化物所联合基金项目(2022009)。

摘　　要：研究了-SO3H基团的引入和不同磺化度对微孔聚酰亚胺气体分离膜的影响.区别于后磺化法,采用一步法使磺化单体2,4,6-三甲基二氨基苯磺酸(TrMSA)和非磺化单体2,4,6-三甲基-间苯二胺(DAM)与六氟二酐(6FDA)直接缩聚得到磺化聚酰亚胺(SPI),通过控制TrMSA和DAM的比例得到磺化度分别为25%,50%,75%与100%的聚合物.使用FTIR、XRD、TGA、BET和气体渗透仪等手段研究不同磺化聚酰亚胺薄膜的化学结构、链段堆积结构、热性能、比表面和气体分离性能.结果显示,引入的-SO_(3)H通过增强链间相互作用力,使得聚合物比表面积减小,以及链间距逐渐降低为0.57、0.52、0.47和0.42 nm,所有气体的渗透性均随磺化度的升高而下降,然而CO_(2)/CH_(4)选择性在扩散系数的主导下则逐渐上升.当磺化度为75%时,磺化聚酰亚胺CO_(2)的透过率达到107 Barrer,CO_(2)/CH_(4)选择性为47.8,在压力高达2 MPa时仍保持在45,证明所制备聚合物具有良好的抗塑化和气体分离性能.In this study,a series of novel sulfonated polyimides is prepared by one-pot high temperature polymerization method.Different from the post-sulfonation method,the degree of sulfonation(DS)can be precisely regulated by varying the ratio of 2,4,6-trimethyl-diaminobenzenesulfonic acid(TrMSA)and 2,4,6-trimethyl-m-phenylenediamine(DAM).The sulfonation degree is controlled to be 25%,50%,75% and 100%.And the effect of DS on the gas separation performance was deeply investigated.The physical properties such as chemical structure,chain packing and thermal properties are systematically studied using FTIR,XRD,TGA,BET,respectively.The results show that as the increment of -SO_(3)H groups,the chain spacing decreases from 0.57,0.52,0.47 to 0.42 nm,due to the strong hydrogen bonding interaction of SO_(3)H group.Consequently,the permeability of gases decreases with the increase of DS,while the selectivity of CO_(2)/CH_(4) gradually increases from 30.8 to 75.4.Particularly,the sulfonated polyimide with DS of 75% displayed a high CO_(2)/CH_(4) selectivity of 47.8 and remained barely unchanged when the pressure increased from O.2 to 2 MPa.In a word,our work provides a deep insight for preparation of novel sulfonated polyimides with high gas separation performance.

关 键 词：磺酸化 气体分离膜 聚酰亚胺 CO_(2)/CH_(4)分离 

分 类 号：TQ31[化学工程—高聚物工业]