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采用湿法纺丝获得聚酰胺酸(PAA)初生纤维,以水和N,N-二甲基乙酰胺(DMAc)的混合溶液作为凝固浴,通过热酰亚胺化制备了均苯四甲酸二酐/4,4’-二氨基二苯醚(PMDA/4,4’-ODA)-聚酰亚胺(PI)纤维。系统研究了阱深长度、凝固浴温度及浓度对PI纤维形貌和性能的影响。结果表明:PAA纤维截面在阱深长度较小、凝固浴温度较低、DMAc浓度较低时呈不规则的腰形,随着阱深长度不断增加,凝固浴温度和浓度的增加,纤维截面都会逐渐趋于圆形。在阱深长度为50cm,凝固浴温度40℃,以3%(体积分数)DMAc作为凝固浴时,所得PAA纤维截面形貌较圆整,且PI纤维性能较好。
Polyamic acid (PAA) primary fibers were obtained by wet spinning. A mixed solution of water and N, N-dimethylacetamide (DMAc) was used as a coagulation bath to prepare bis Anhydride / 4,4’-oxydianiline (PMDA / 4,4’-ODA) -polyimide (PI) fiber. The effect of well depth, temperature and concentration of coagulation bath on morphology and properties of PI fibers was systematically investigated. The results show that the cross section of PAA fiber is smaller in the depth of the well, the temperature of the coagulation bath is lower and the shape of the irregular waist is irregular when the DMAc concentration is lower. As the length of the well depth increases and the temperature and concentration of the coagulation bath increase, Gradually tends to be round. When the depth of the well is 50cm and the temperature of the coagulation bath is 40 ℃, DMAc is used as the coagulation bath at a volume fraction of 3%. The cross-section morphology of the obtained PAA fiber is more rounded and the properties of the PI fiber are better.