Physical properties: polypropylene is a non-toxic, odorless,odorless, opalescent, highly crystalline polymer with a density ofonly 0.90 --" 0.91g /cm3, making it one of the lightest plasticsavailable. It is particularly stable to water, with a waterabsorption rate of 0.01% and a molecular weight of about810,000,000. Good formability, but because of the shrinkage rate(1%~2.5%). Thick wall products are easy to sag, for some parts withhigher dimensional accuracy, it is difficult to meet there, the surface of the products good gloss.
聚丙烯PP的介绍:PP(聚丙烯)有很多有用的性能,但还缺乏固有的韧性,特别是在低于其玻璃化温度的条件下。然而,通过添加冲击改性剂,可以提高其抗冲击性能。传统改良性为弹性体,通常为乙丙橡胶。普遍认为,遍布于半结晶态聚丙烯基体内的橡胶粒子,能在界面上形成许多应力集中点,防止局部形变,和断裂扩展。抗冲击改性剂一直是在共混时添加进去的,近,弹性体组分的现场合成已经具有商业重要性。而且,正在宣传用一种新系列的冲击改性剂来代替乙丙橡胶,即Flexomer聚烯烃、Exact塑弹体和Insite聚合物。这些都是烯烃聚合物,它们填补了极低密度聚乙烯和传统乙丙弹性体之间的空白。