一种可溶性聚酰亚胺的合成及其渗透汽化脱有机硫化物性能测试

由3,3′,4,4′-二苯醚四甲酸二酐(ODPA)和3,3′-二甲基4,4′二氨基二苯甲烷(DMMDA)二胺为单体,利用低温溶液缩聚化学亚胺化法合成了ODPA DMMDA聚酰亚胺.利用FT IR、NMR与DSC等手段对聚酰亚胺的结构进行了表征;研究了其溶解性能、耐热性能和力学性能.结果表明,此聚酰亚胺可溶于DMF、DMAc等极性溶剂;玻璃化转变温度为264℃,其10%的热分解温度为521℃;断裂强度为137MPa;断裂伸长率为18%.采用相转化法将其制成非对称膜,采用扫描电子显微镜(SEM)观察内部结构,在渗透汽化脱硫实验中,对噻吩有良好的选择透过性能.350K时,硫富集率为3.68,渗透通量为0.92kg m2h.

SYNTHESIS AND PERVAPORATION PERFORMANCE TO GASOLINE DEORGANICSULFIDE OF SOLUBLE POLYIMIDE

A kind of soluble polyimide (PI) was synthesized based on 4,4′-oxydiphthalic dianhydride (ODPA) and 4,4′-diamino-3,3′-dimethyldiphenylmethane (DMMDA) via low temperature solution polycondensation and chemical imidization.The structure and properties of the obtained PI were characterized by measurements of FT-IR, 1H-NMR,DSC and TGA etc.The results showed that the PI was readily soluble in polar solvents such as DMF,DMAc and NMP etc.Its glass transition temperature was 264℃ and 10% thermal decomposition temperature under N_2 was 521℃.The tensile strength was 137 MPa, and the elongation at break was 18%.The asymmetry membrane was prepared by phase inversion method of ODPA-DMMDA and was observed by SEM.In the sulfur reduction experiments,the membranes display good selectivity and high pervaporation performance for thiophene in the gasoline.The enrichment factor was 3.68 and the flux was 0.92 kg/m2h when tested with a n-heptane/thiophene feed at 350 K.