摘要
聚对苯二甲酰对苯二胺(PPTA)的相对分子质量和相对分子质量分布直接影响芳纶纺丝性能。PPTA主链间的氢键作用使其难溶于氯仿等常用有机溶剂中,不能满足核磁共振波谱仪、质谱和凝胶渗透色谱法等测试要求。为了提高PPTA的溶解性,通过主链上N位接枝系列不同种类和取代程度的烷基侧链,得到可溶解的烷基化PPTA,考察了不同烷基种类和烷基化条件对相对分子质量以及相对分子质量分布的影响。乙基烷基化PPTA的取代程度可达98.6%,有利于得到多分散系数较低和更为准确的相对分子质量分布。根据马克霍温克方程,得到了特定黏度范围内重均相对分子质量与特性黏数的关系公式为[η]=9.96×10^(-3)M_(w)^(1.08),对优化PPTA合成条件和改善芳纶纤维的性能提供了参考。
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 molecularmass 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)M_(w)^(1.08).These results could be utilized for optimizing PPTA synthesis and improving the performance of aramid fiber.
作者
杨林涛
李茂
YANG Lin-Tao;LI Mao(State Key Laboratory of Polymer Physics and Chemistry,Changchun Institute of Applied Chemistry,Chinese Academy of Sciences,Changchun 130022,China;University of Science and Technology of China,Hefei 230026,China)
出处
《应用化学》
CAS
CSCD
北大核心
2023年第6期853-859,共7页
Chinese Journal of Applied Chemistry
