聚苯乙烯在应力作用下的降解动力学及降解机理研究

了聚苯乙烯在振动磨中的力降解动力学和降解机理，对Ｂａｒａｍｂｏｉｍ所推导的聚合物力降解动力学方程进行了修正。修正方程可更准确地描述本乙烯在振动磨中降解时的分子量变化过程。实验结果表明，聚苯乙烯在振动磨中的降解机理依赖于聚苯乙烯所受的应力强度。当应力强度较不时的聚苯乙烯的降解机理是人规断链过程；在应力强度较大时，聚苯乙烯的降解机理则是分子链多和同时发生断裂的一个非无规断链过程。

A STUDY ON MECHANOCHEMICAL DEGRADATION KINETICS AND MECHANISM OF POLYSTYRENE

The mechanochemical degradation mechanism and kinetics of PS during vibromilling were studied in this paper. A kinetic equation of mechanochemical degradation based on Baramboim equation is derived. The molecular weight of PS during vibromilling can be precisely predicted by this modified kinetic equation. The GPC results show that the mode of mechanochemical degradation of PS during vibromilling depends on the intensity of stress applied to the PS molecular chain. The degradation will be a random chain scission process when lower stress is applied. In the case of higher stress, the degradation is a non random chain scission process via concurrent multiple breakage.