HDPE/sPS共混体系结构与性能的研究

用2种分子量不同的苯乙烯-(乙烯/丁烯)-苯乙烯三嵌段共聚物(SEBS)和一种苯乙烯-b-乙烯/丁烯(SEB)两嵌段共聚物为增容剂,对高密度聚乙烯(HDPE)/间规聚苯乙烯(sPS)共混物进行增容.采用扫描电镜(SEM)及拉伸试验研究了增溶剂的分子量及结构对共混物形态结构及力学性能的影响.结果表明:3种增容剂SEBS(SEB)均可有效地降低sPS分散相的尺寸并增加HDPE/sPS共混物的界面强度,从而提高其力学性能.sPS 的掺入可以显著提高HDPE的耐热性能.

Morphology and Mechanical Properties of HDPE/sPS Blends

Two triblock copolymers of polystyrene-b-(ethylene-co-butylene)-b-styrene ](SEBS) of different molecular weights and one diblock copolymer of poly styreneb-(ethylene-co-butylene)(SEB) were used to compatibilize high density polyethylene/syndiotactic polystyrene(HDPE/sPS) blend.Morphology observation showed that phase size of the dispersed sPS particles was significantly reduced on addition of all the three copolymers and the interfacial adhesion between the two phases was dramatically enhanced.Tensile strength of the blends increased at lower copolymer content but decreased with increasing copolymer content.The elongation at break of the blends was improved and sharply increased with increment of the copolymers,particularly at the high copolymer content.Measurements of Vicat softening temperature of the HDPE/sPS blends show that heat resistance of HDPE is greatly improved upon incorporation of 20 wt % sPS.