烷基取代聚对苯二甲酰对苯二胺的相对分子质量 以及相对分子质量分布分析.

The molecular-mass and its distribution of poly（p-phenylene terephthamide）(PPTA） directly affect the spinning performance of aramid fiber. The hydrogen bonds between PPTA backbones make PPTA insoluble in common organic solvents such as chloroform， which cannot meet the test requirements of proton magnetic resonance， mass spectroscopy， and gel permeation chromatography （GPC). The soluble n-alkylated PPTAs are obtained by grafting a series of alkyl chains with different lengths and degrees of supersede on the N-position of PPTA backbones. The influence of alkyl lengths and alkylation conditions on relative molecular-mass and its distribution are further studied. Ethyl alkylated PPTA with the highest substitution degree of 98.6% enables to provide the lowest polydispersion coefficient and the more accurate molecular-mass distribution. The relationship between the average relative molecular-mass and the intrinsic viscosity in a specific viscosity range is obtained according to the Makhovink equation ［η］= 9. 96×10-3 Mw1.08 . These results could be utilized for optimizing PPTA synthesis and improving the performance of aramid fiber. [ABSTRACT FROM AUTHOR]