PP-EPR-PP增容PP/EPT的研究

PPEPRPP BLOCK COPOLYMER COMPATIBILIZING PP EPT

采用δ－ＴｉＣｌ３－Ｅｔ２ＡｌＣｌ催化合成了三元乙丙嵌段共聚物ＰＰ－ＥＰＲ－ＰＰ，作为乙丙橡胶（ＥＰＴ）增韧聚丙烯（ＰＰ）的增容剂，以改善ＰＰ的低温冲击性能。实验发现，ＰＰ－ＥＰＲ－ＰＰ中ＥＰＲ段较长，有利于提高其增容效果，ＰＰ－ＥＰＲ－ＰＰ的加入量仅为４％，就可以显著的改善ＰＰ和ＥＰＴ相容性，使ＰＰ／ＥＰＴ／ＰＰ－ＥＰＲ－ＰＰ共混物的无缺口冲击强度比相应的ＰＰ／ＥＰＴ在－２０℃时提高４０％，在－４０℃时提高了１２０％，达到较高的耐冲击等级。形态观察表明，ＰＰ－ＥＰＲ－ＰＰ同时又起到了“乳化剂”的作用，使ＥＰＴ在ＰＰ中均匀分散。还提出了ＰＰ－ＥＰＲ－ＰＰ的增容模型，完满地解释了实验结果。

A series of different segmental length block copolymers of PPEPRPP, prepared by ZieglerNatta polymerization, could be used as compatibilizers of EPT rubber toughening polypropylene(PP). Experiments show that unnotched impact strength(σi) of PP/EPT/PPEPRPP rises quickly if EPR segment of PPEPRPP becomes longer and PPEPRPP proportion in blend increases from 0 to 4 percent. The σi of PP/EPT/PPEPRPP(85/15/4) is 1.4 times of PP/EPT(85/15) at -20 ℃, 2.2 times at -40 ℃. Scanning electron micrograph and dynamic mechanical spectra show that PPEPRPP compatibilizes EPT/PP efficiently and reduces the stress of two phases.