摘要
利用均苯四甲酸二酐(PMDA)与4,4'-二氨基二苯醚(ODA)和聚醚胺(PPO,M_(n)~2000)共聚合,合成聚酰胺酸前驱体,经热处理得到一系列含PPO链段的聚酰亚胺薄膜.研究了PPO链段的引入对薄膜结构及气体分离性能的影响.结果表明,在芳香族聚酰亚胺中引入柔性链段PPO有利于气体分子的传输.得益于PPO链段在分离膜内部形成的微相分离结构,气体分子在分离膜内的扩散系数随PPO含量的增加显著提升.当PPO含量为65 wt%时,PPO链段在分离膜内仍呈现非晶相,CO_(2)渗透系数高达131.61 Barrer,比PMDA/ODA均聚聚酰亚胺薄膜提高22倍.同时,得益于聚醚链段对CO_(2)独特的亲和作用,随着PPO含量的提高,分离膜对CO_(2)/N_(2)的分离系数由18.77提高至30.12.结果表明PPO链段的引入对于调控聚酰亚胺膜的结构和气体分离性能具有重要作用.
A series of polyimide membranes containing polyether amine(PPO)segment were successfully synthsized by thermal imidization of the poly(amic acid)(PAA)precursors copolymerized of pyromellitic dianhydride(PMDA)with 4,4'-diaminodiphenyl ether(ODA)and amine functionalized polyether amine(M_(n)~2000).The effects of PPO on the microstructure and gas separation property of the resultant membranes were investigated in detail.The results show that the fractional free volume(FFV)of the membranes increases with the content of the PPO.Meanwhile,a micro-phase separation behavior is detected in the resultant membranes with the incorparation of PPO,which can act as the continuous gas transmission channel.As a consequence,the permeability of the membrane increases rapiadly.As the PPO content reaches 65 wt%,the CO_(2) permeability is as high as 131.61 Barrer,which is nearly 22 times higher than that of the PMDA/ODA homopolyimide membrane.Moreover,due to the special interaction between the PPO and CO_(2),the CO_(2)/N_(2) selectivity increases from 18.77 for the PMDA/ODA membrane to 30.12 for the copolyimide membrane with 65 wt%PPO.Accordingly,the incorporation of PPO plays an important role in modifying the microstructure and gas separation property for the polyimide membranes.
作者
肖娴
徐小尘
李琇廷
董杰
赵昕
张清华
Xian Xiao;Xiao-chen Xu;Xiu-ting Li;Jie Dong;Xin Zhao;Qing-hua Zhang(State Key Laboratory of Fiber Material Modification,Donghua University,Shanghai 201620)
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2022年第5期505-513,共9页
Acta Polymerica Sinica
基金
国家自然科学基金(基金号51903038,52173196,21774019)资助项目.
关键词
聚酰亚胺
聚醚胺
气体分离膜
相分离
Polyimide
Polyether amine
Gas separation membrane
Micro-phase separation
