一种可溶性聚酰亚胺的合成与性能研究

选用三苯二醚四酸二酐 (HQDPA)和二甲基二苯甲烷二胺 (DMMDA)为单体 ,在NMP中通过低温溶液缩聚 化学亚胺化法合成了高分子量可溶性聚醚酰亚胺PI(HQDPA DMMDA) .通过FT IR、WAXD、TG DTG以及DSC等手段对聚酰亚胺的结构和性能进行了表征 .结果表明 ,合成的PI为无规高分子结构 ,平均分子链间距为 0 5 16 3nm ;易溶于N 甲基吡咯烷酮、N ,N 二甲基乙酰胺和四氢呋喃等极性溶剂中 ;其 10 %的分解温度为5 2 8℃ ,玻璃化转变温度Tg 为 2 5 1℃ ;断裂伸长率为 2 4 % ,断裂强度为 10 7MPa ;2 5℃时 ,PI均质膜的透H2 系数为 3 80 9Barrer ,H2 N2 、H2 CH4 的理想分离系数为 16 6 9、2 14 0 ;其透N2 、O2 、CO2 和CH4 系数均在 0 0 18～0 5 76Barrer之间

STUDY ON SYNTHESIS AND PROPERTIES OF AN ORGANIC SOLUBLE POLYIMIDE

An organic soluble and high molecular weight polyetherimide(HQDPA DMMDA) was synthesized based on the HQDPA and DMMDA in NMP by the low temperature solution co polymerization method.The structure and properties of the PI were characterized by measurements of FT IR,WAXD,TGA and DSC etc. The results showed that the obtained polyetherimide had an amorphous structure with a d spacing of 0 5163 nm.The PI was readily soluble in polar solvents such as NMP, DMF and THF etc. Its glass transition temperature was 251℃ and 10% thermal decomposition temperature under N-2 was 528℃.The tensile strength was 107 MPa and the elongation at break was 24%.The permeability data of polyimide membrane for gases such as H 2, N 2,O 2, CO 2 and CH 4,were collected at 25℃.The permeability for H 2 was 3 809 Barrer and the ideal selectivity coefficients for H 2/N 2 and H 2/CH 4 were 166 9 and 214 0,respectively.The permeability for N 2, O 2,CO 2 and CH 4 were between 0 018～0 576 Barrer.