双单体固相接枝聚丙烯的流变性能

以过氧化苯甲酰为引发剂制备了苯乙烯、乙酸乙烯酯对马来酸酐和聚丙烯（PP）的二元固相接枝共聚物，并对其结构与性能进行了研究，探讨了剪切应力、剪切速率和温度对固相接枝改性PP熔体流动行为、熔体粘度的影响．结果表明：固相接枝改性PP的熔点和热焓比纯PP的相应值均有所下降；其非牛顿指数n值比纯PP的n值有所增加，说明改性后PP的熔体流动比纯PP偏离非牛顿型流体；其粘流活化能（Eη）比纯PP的Eη有大幅度提高，说明接枝改性后PP的表观粘度对温度的变化非常敏感．

Rheological behavior of solid- state grafting copolymerization of bimonomer onto polypropylene

Polypropylene was grafted with maleic anhydride and other two monomers,styrene or vinyl acetate and BPO as a initiator.The structures of the grafted copolymers were characterized by IR and DSC,and their rheological behaviors were studied by means of capillary rheometer,respectively.The results were shown as follows:the DSC diagrams demonstrated that the effect of solid-state grafting modification on PP led to the decreases of the melt point and the enthalpy,and the non-Newtonian indexes of the grafted PP were higher than that of pure PP.It indicated that the melt flow behavior of the former departure from the non Newtonian fluid more than that of the latter.It was found that the melt flow of the modified PP was more sensitive to temperature than that of pure PP due to the greatly increasing viscosity activation energy of the modified PP.