聚丙烯/聚苯乙烯共混合金Ⅱ.结晶和性能

用偏光显微镜、DSC、DMA分析法和拉伸试验等方法对PP／PS／PP-g-PS熔融共混合金的结晶行为、形态和拉伸强度进行了研究。结果表明，PP-g-PS减轻了PS相对PP相结晶行为的干扰，合金的拉伸强度明显上升。上述变化均与PP-g-PS在合金中的含量有关。

STUDY ON THE PP/PS BLEND ALLOY Ⅱ. THE CRYSTALLIZATION AND PROPERTIES

In our preliminary study, it has been revealed that the particle size of dispersion phase at PP/PS alloy and the homogeneity of PP/PS alloy were improved after the graft copolymer PP-g-PS. At present the influence of PP-g-PS on the crystal morphology, crystal behavior and mechanical property of PP/PS alloy will be reported further. The test results of optical polarizing microscope and DSC show that the PP/PS alloy and PP/PS/PP-g-PS alloy exhibits different crystalline behavior. The size of PS phase of PP crystal at PP/PS/PP-g-PS alloy is lower than at PP/PS alloy, but the crystallinity of PP phase at PP/PS/PP-g-PS alloy is higher than at PP/PS alloy. These changes increase when the PP-g-PS content increases. Tensile test shows that PP/PS alloy without PP-g-PS exhibits poor tensile strength owing to weak interfacial adhesion. However PP/PS alloy with improved mechanical properties can achieved by addition of PP-g-PS as a compatibilizer because its addition to the alloy can enhance the adhesion between the PP and PS phases.