碳纤维增强聚酰亚胺复合材料的碳化研究

Carbonization Treatment on Performance of Carbon Fibre Reinforced Polyimide Composite Materials

利用模压成型法制备了碳纤维增强聚酰亚胺复合材料(CF/PI),研究了不同碳化温度下,CF/PI复合材料的结构以及性能的变化规律。结果表明,500~800℃,热失重显著,对应亚酰胺环沿着C-N键断裂,先后发生脱羰基、脱氢反应。碳化后,分子处于无序态,力学性能大幅下降;800~1000℃,分子内官能团进行重组,900℃碳化后出现了表征碳材料(110)面的衍射峰,且力学强度达到最大值,复合材料的碳层结构逐渐形成。随着碳化温度的增加,基于聚酰亚胺与碳纤维的相互作用,复合材料的界面结合情况得到改善,且900℃碳化后,复合材料具有最佳综合性能。

A carbon fiber reinforced polyimide composite material(CF/PI) was prepared by compression molding. Then the effect of carbonization treatment on the change of structure and property of CF/PI was studied. The results show that the weight loss of CF/PI is obvious during carbonization treatment at temperature from 500℃ to 800℃, implying the occurrence of the rupture of imides rings along C-N bonds, i.e. reactions of dehydroxylation and dehydrogenation occur successively. After carbonization,molecules of CF/PI are in a state of disorder, thus its mechanical performance falls sharply; at temperature from 800℃ to 1000℃, with the recombination of functional groups within molecules, carbon layer structure forms gradually in the composite, while the characteristic diffraction peak(110) of carbon may be detected and correspondingly the mechanical strength reaches the maximum for the composite carburized at 900 oC. The interfacial bond of the composite is enhanced with the increasing carbonization temperature, which is resulted from the heat activated interaction of polyimide with carbon fiber. The best comprehensive performance can be obtained for the CF/PI after carbonization treatment at 900℃.