剪切速率对直接法制备芳纶浆粕缩聚反应影响的研究

研究了剪切速率对低温溶液直接缩聚法制备聚对苯二甲酰对苯二胺浆粕(芳纶浆粕，PPTAPulp)缩聚反应过程的影响。利用PPTA刚性分子发生逐步缩聚反应的缩聚模型，解释了在缩聚反应过程中，分子链的取向是提高PPTA相对分子质量的必要条件。实验结果表明，提高剪切速率有利于PPTA分子沿流动方向取向，从而提高缩聚反应速率以及芳纶浆粕的相对分子质量，同时还有利于提高浆粕的长径比(L／D)。

Effect of Shear Rate on the Solution Polycondensation for Preparing Poly(p-phenylene terephalamide) Pulp at Low Temperature

The effect of shear rate on the solution polyeondensation for preparing poly (pphenyleneterephalamide) (PPTA)pulp at low temperature was studied. The requirement of the orientation of PPTA chains during the polycondensation for high molecular weight of PPTA was explained by the polycondensated mode of PPTA molecules. It has been shown that the polycondensated rate can be accelerated and the molecular weight and the aspect ratio(L/D) of the resultant PPTA pulps can be improved due to the increase of the shear rate, which leads to the orientation of PPTA chains along the flowing direction.