The polypropylene used for making cigarette filters was prepared with the process of free radical graft copolymerization in order to raise the selfadhesive power and surface energy of the PP.

用自由基化学接枝共聚的方法制作聚丙烯香烟滤材，以提高其表面能，增加自粘性。

youdao

PP-R health drug-free high-tech products, household decoration is currently more widely used for a pipe.

PP-R 管是一种卫生无毒的高新技术产品，也是目前家庭装修中较普遍使用的一种给水管。

youdao