化学亚胺法催化制备性能优异的聚酰亚胺纤维

Catalytic preparation of polyimide fibers with excellent properties bythe chemical imide method

提高本征性高分子纤维材料的热稳定性和力学性能,是目前先进纤维材料的研究热点。聚酰亚胺是一种高性能特种高分子材料,由于其共轭及苯环堆叠作用,具有优异的力学性能和热稳定性。将4,4′-二氨基二苯醚(ODA)、对苯二胺(PDA)两种二胺与3,3′,4,4′-联苯四甲酸二酐(BPDA)聚合形成聚酰胺酸溶液(PAA),使用不同种类的吡啶与丙酸酐混合制备出一系列浓度梯度混合液引入到PAA中,采用湿法纺丝和化学亚胺化法制备出聚酰亚胺纤维并对其微观结构和性能进行研究。结果表明,当4-甲基吡啶质量分数为4%(质量分数),n(PAA)∶n(丙酸酐)=1∶3时的聚酰亚胺纤维微观结构为标准的圆柱状,其拉伸强度达到1.91 GPa,在热失重为5%时的温度高达533.3℃,表现出良好的热稳定性能和力学性能。

Enhancing the thermal stability and mechanical properties of intrinsic polymer fiber materials is currently a hot research topic in advanced fiber materials.Polyimide is a high-performance specialty polymer material with excellent mechanical properties and thermal stability due to its conjugation and benzene ring stacking.Two diamines,4,4′-diaminodiphenyl ether(ODA)and p-phenylenediamine(PDA),were polymerized with 3,3′,4,4′-biphenyltetracarboxylic acid dianhydride(BPDA)to form polyamidoacetic acid solution(PAA),and a series of concentration-gradient mixtures were prepared by using different kinds of pyridine mixed with propionic anhydride and introduced into PAA.The polyimide fibers were prepared by wet spinning and chemical imidization and their microstructures and properties were investigated.The results showed that when the mass fraction of 4-methylpyridine was 4 wt%and n(PAA)∶n(propionic anhydride)=1∶3,the microstructure of the polyimide fiber was a standard cylindrical shape with tensile strength reaching 1.91 GPa.The temperature was as high as 533.3℃at a heat loss of 5%,which exhibited good thermal stability and mechanical properties.