氯化聚丙烯超声降解的动力学

Kinetics of Chlorinated Polypropylene under Ultrasonic Irradiation

测定了不同浓度氯化聚丙烯(CPP)甲苯溶液超声降解的分子量,并用数据拟合法求出了聚合物超声降解极限分子量。由于常用的超声降解动力学方程对实验数据拟合的精度不能令人满意,为了准确建立CPP在甲苯溶液中的超声降解动力学方程,提出了一个改进的动力学方程式:1Mt-Mlim-M0-1Mlim=kt。它能准确地描述CPP超声降解过程。用该方程拟合的聚合物超声降解数据,效果比文献提供的方程好。在超声降解过程中,随CPP浓度的增大极限分子量增大而降解速率常数则减小。

Molecular weights of chlorinated polypropylene at various concentrations under ultrasonic irradiation were measured. Limiting molecular weight of polymers under ultrasonic irradiation could be obtained by data fitting technique. Siwe the fitting accuracy of the common kinetic equations of polymers under ultrasonic irradiation for experimental data was evaluated. The fitting results of these kinetic equations for experimental data are not satisfactory, in order to establish the kinetic equation for chlorinated polypropylene in toluene accurately, an improved kinetic equation for ultrasonic degradation was proposed in this article： 1/Mt-Mlim-1/M0-Mlim=kt. It describes well the ultrasonic degradation grocess of chlorinated polypropylene. The fitting effect for some experimental data in literature using the new equation is better than that of the kinetic equations used in literature. For chlorinated polypropylene under ultrasonic irradia- tion, the rate coefficients decrease with increasing concentration and the limiting molecular weights in- crease with increasing concentration.