A HIGH-PERFORMANCE AROMATIC POLYIMIDE FIBER .1. STRUCTURE, PROPERTIES AND MECHANICAL-HISTORY DEPENDENCE
A HIGH-PERFORMANCE AROMATIC POLYIMIDE FIBER .1. STRUCTURE, PROPERTIES AND MECHANICAL-HISTORY DEPENDENCE
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DOI：
10.1016/0032-3861(91)90367-r
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发表时间：
1991-01-01
期刊：
影响因子：
4.6
通讯作者：
HARRIS, FW
中科院分区：
文献类型：
--
作者：
CHENG, SZD;WU, ZQ;HARRIS, FW
以3,3',4,4'-联苯四羧酸二酐（BPDA）和2,2'-双（三氟甲基）-4,4'-二氨基联苯（PFMB）为原料合成了一种新的分段刚性棒聚酰亚胺。这种聚酰亚胺可溶于热间甲酚，允许纤维从各向同性的溶液中使用干喷湿纺丝方法纺丝。原纺纤维的韧性和模量较低，但可以在高温（380℃）下拉伸至大拉伸比（高达10倍），从而显著提高强度和模量。拉伸纤维的拉伸强度约为25 g den-1 (3.2 GPa)，初始模量高于1000 g den-1 （130 GPa）。BPDA-PFMB纤维表现出优异的热稳定性，并在高温下保持相对较高的强度和模量。退火的BPDA-PFMB纤维显示出明显的广角x射线模式，从中确定了单斜晶胞。此外，还观察了不同拉伸率下晶体c轴、表观晶体尺寸、结晶度、晶体取向和热机械性能的变化。
A new segmented rigid-rod polyimide has been synthesized from 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) and 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (PFMB). This polyimide is soluble in hot m-cresol, allowing fibres to be spun from an isotropic solution using a dry-jet wet spinning method. The as-spun fibres have low tenacities and low moduli, but they can be drawn at high temperatures (> 380-degrees-C) under tension to large draw ratios (up to 10 times), which produces a remarkable increase in strength and modulus. Drawn fibres display a tensile strength of about 25 g den-1 (3.2 GPa) and an initial modulus higher than 1000 g den-1 (130 GPa). BPDA-PFMB fibres show excellent thermal stability and retain relatively high strength and modulus at elevated temperatures. Annealed BPDA-PFMB fibres display distinct wide-angle X-ray patterns, from which a monoclinic unit cell has been determined. Furthermore, changes in crystallographic c-axis, apparent crystal sizes, degree of crystallinity, crystal orientation and thermomechanical properties have been observed with different draw ratios.