溶液浓度对聚丙烯腈聚合动力学的影响

在试验的过程中,发现了动力学方程中转化率的理论值与实际值之间的差别,实际转化率的最大值为95%,而理论转化率的最大值为64%,经分析,认为体系浓度变化是造成这一差别的主要原因。为了进一步研究溶液浓度对聚合动力学的影响,将聚丙烯腈溶入二甲基亚砜,配制不同含固率的溶液,将溶液作为反应介质,以丙烯腈和丙烯酰胺为反应单体进行反应。结果发现,体系浓度与链终止速率常数的指前因子呈线性关系,即链终止速率常数的指前因子随体系浓度的增大而减小,动力学方程经浓度修正以后,在转化率小于50%时,转化率的理论值与实际值吻合得很好。

Influence of Solution Concentration on Reaction Kinetics of PAN

During the experiment,the differences were found between the academic conversion ratio and the actual one in the kinetic equation,the academic max was 64% and the actual max was 95%.The principal cause of that was the concentration variety.For the further research of the concentration influence on the kinetics,polyacrylonitrile(PAN) was dissolved in dimethyl sulfoxide(DMSO) in different contents as the reaction medium.PAN and acrylamide(AM) copolymerized in the solution.The result shows that the relation between the pre-exponential factor and the concentration is linear and the pre-exponential factor decreases as the concentration increases.On the base of amendment with concentration,the academic conversion is consistent with the actual one,when the conversion is under 50%.