PP will degrade due to heat during processing, resulting in chain scission of macromolecule, reduction in molecular weight and rise in MI.
聚丙烯在加工时受热将发生大分子断链降解，致使分子量减小，熔体指数上升。
2
The dependence of chain scission and racemization on temperature results from molecular motion, "cage effect" and steric hindrance during recombination.
分子量降低和消旋作用对温度的依赖性，是由于分子运动和笼罩效应以及重合的空间位阻效应所致。
3
The invention relates to a method for preparing low-molecular vegetable gum through chain scission of macromolecular vegetable gum by a physical or chemical method.