采用4,4'-二氨基二苯醚和1,6-己二胺(HDA)为二胺单体,与均苯四甲酸酐(PMDA)在二甲基乙酰胺(DMAc)中共聚得到聚酰胺酸(PAA)纺丝原液,通过干法纺丝工艺路线纺制PAA初生纤维,利用热酰亚胺化制备了共聚型聚酰亚胺(PI)纤维;通过红外光谱分析、动态力学分析、热重分析、X射线衍射等手段分析了PI纤维的力学性能及热性能.结果表明:红外光谱分析发现HDA的长亚甲基链引入到PI的链中;当HDA质量分数为20％时,PI纤维的断裂强度和模量分别为5.1 cN/dtex和76 cN/dtex;动态力学和热重分析发现,纤维的玻璃化转变温度为315 ～ 380℃,热稳定性在400℃以上;纤维经热处理后聚集态结构存在一定的有序性.%A polyamic acid (PAA) spinning solution was synthesized by copolymerization reaction of pyromellitic dianhydride (PMDA) and two diamines,namely 4,4'-diaminodephenylether (ODA) and 1,6-hexamethylenediamine (HDA),in dimethylacetamide (DMAc).The PAA solution was spun into fibers by dry spinning process and was continuously produced into copolymerized polyimide (PI) fibers by thermal imidization.The mechanical properties and thermal property of the PI fibers were analyzed by infrared spectroscopy,dynamic mechanical analysis,thermogravimetric analysis and X-ray diffraction.The results showed that the long methylene chain of HDA was successfully introduced into the main chain of PI; the breaking strength and modulus of the fiber were 5.1 cN/dtex and 76 cN/dtex,respectively,when the mass fraction of HDA was 20％ ; the glass transition temperature of the fiber was 315-380 ℃ and the thermal stability was above 400 ℃ ; and the ordered aggregation state formed after heat treatment.
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