SEBS增容等规聚丙烯/间规聚苯乙烯共混体系的结构与性能

Morphology and Mechanical Properties of Isotactic Polypropylene/Syndiotactic Polystyrene Blends Compatibilized by SEBS Copolymers

用3种组成相近而分子量不同的苯乙烯-乙烯/丁烯-苯乙烯共聚物(SEBS)作为增容剂,对等规聚丙烯/间规聚苯乙烯(iPP/sPS)共混物进行增容。研究了共聚物的分子量对iPP/sPS共混物的形态结构及力学性能的影响。结果表明,中、低分子量的SEBS具有较好的增容作用,能有效提高共混物的拉伸强度;而高分子量的SEBS则能显著改善共混物的韧性。用SEM观察了增容剂在共混物中的分布情况,揭示了共混物的力学性能不仅取决于增容剂的界面活性,而且还与增容剂在共混物中的分布密切相关。

The effects of three triblock copolymers of poly [styrene-b-（ethylene-co-butylene）-b-styrene]（SEBS） of different molecular weight（MW） on the morphology and tensile strength of isotactic polypropylene/syndiotactic polystyrene（PP/sPS,80/20） blend were investigated.Morphology observation shows that both the medium MW and the lower MW SEBS are more effective than the higher MW SEBS in compatibilizing the blends.Tensile test reveals that both the medium and low MW compatibilizers lead to a significant improvement in tensile strength,while the higher MW compatibilizer is efficient in increasing the elongation at break of the blends.The localization of compatibilizers in the blends was observed by means of scanning electron microscope（SEM） and the correlation between the distribution of the compatibilizers and mechanical properties of the blends was evaluated.