【摘要】 以均苯四甲酸二酐(PMDA)为二酐单体,4,4′-亚甲基二(2-特丁基苯胺)(MBTBA)和对苯二胺(PDA)为二胺单体,经高温溶液缩聚合成了一系列可溶性共聚聚酰亚胺,采用IR、NMR、GPC、UV-Vis、TGA、DMA等测试方法对所得共聚酰亚胺进行了表征,并采用1H-NMR谱来确定其共聚组成,考察了两种二胺单体的不同摩尔配比对共聚酰亚胺溶解性、耐热性和透光性的影响.更多还原

【Abstract】 A series of aromatic copolyimides was successfully synthesized from the commercial pyromellitic dianhydride （PMDA） with the commercial diamine p-phenyldiamine （PDA） and the diamine 4,4′-methylenebis-（2-tert-butylaniline） （MBTBA） specially designed by ourselves.The copolyimides were characterized by IR,NMR,GPC,UV-Vis,TGA and DMA.The copolyimide was precipitated in m-cresol in the polymerization process when the molar ratio of MBTBA and PDA was lower than 6/4.The number-average molecular weight of the soluble copolyimides measured by GPC was larger than 4.0×10⁴ and the polydispersity index was higher than 1.5.Only one glass transition temperature of these copolyimdies was detected around 360℃ by DMA.The copolyimides did not show appreciable decomposition up to 500℃ under N₂,and the thermal stability of the copolyimide increased a little with the introduction of the PDA into the polymer chains.更多还原