【摘要】 采用３，３′－二甲基－４，４′－二氨基二苯甲烷，４，４′－二氨基二苯醚或４，４′－二氨基二苯甲烷为共缩聚二胺单体与二苯醚３，３′－，４，４′－四酸二酐进行缩聚制备共缩聚型聚酰亚胺。当３，３′－二甲基－４，４′－二氨基二苯甲烷与４，４′－二氨基二苯醚的摩尔比为１０∶０～４∶６或３，３′－二甲基－４，４′－二氨基二苯甲烷与４，４′－二氨基二苯甲烷的摩尔比在１０∶０～５∶５时，所得聚酰亚胺可溶解于强极性有机溶剂。所得可溶性聚酰亚胺在ＮＭＰ中的特性粘度在０．８７～１．４５ｄＬ／ｇ．它们在氮气中的热降解起始温度在５０４℃以上，并且在研究范围内与共聚二胺的结构及比例无明显关系。更多还原

【Abstract】 Cocondensation type polyimides were prepared by using 3,3′-dimethyl-4,4′-diamino diphenylmethane and 4,4′-diamino diphenylether or 4,4′-diamino diphenylmethane as the co-diamine monomers and diphenylether-3,3′,4,4′-tetracarboxylic acid dianhydride as the dianhydride monomer. The polyimides were observed to be soluble in strong polar solvents only when the molar ratio of 3,3′-dimethyl-4,4′-diamino diphenylmethane and 4,4′-diamino diphenylether was 10∶0-4∶6, or that of 3,3′-dimethyl-4,4′-diamino diphenylmethane and 4,4′-diamino diphenylmethane was 10∶0-5∶5. The intrinsic viscosity of soluble polyimides in NMP was observed to be 0.87-1.45 dL/g. The thermal decomposition temperature of soluble polyimides in N₂ was observed to be above 504 ℃ and almost independent of the structure and molar ratio of the co-diamine monomers studied.更多还原