一种可溶性聚酰亚胺的合成与性能研究

STUDY ON SYNTHESIS AND PROPERTIES OF AN ORGANIC SOLUBLE POLYIMIDE

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

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 251degreesC and 10% thermal decomposition temperature under N-2 was 528degreesC. 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, CO2 and CH4, were collected at 25 degreesC The permeability for H-2 was 3.809 Barrer and the ideal selectivity coefficients for H-2/N-2 and H-2/ CH4 were 166.9 and 214.0, respectively. The permeability for N-2, O-2, CO2 and CH4 were between 0.018 similar to 0.576 Barrer.