DSC对PVC／LLDPE共混体系相容性的研究

THE STUDIES ON COMPATIBILITY OF POLYMER BLENDS BY DSC

用示差扫描量热仪（ＤＳＣ）对聚氯乙烯／线型低密度聚乙烯（ＰＶＣ／ＬＬＤＰＥ）共混体系的相容性进行了研究，发现氢化后的聚丁二烯－ｂ－甲基丙烯酸甲酯（ＨＰＢＤ－ｂ－ＰＭＭＡ）共聚物在共混体系中可以起到很好的增容作用。共聚物增容剂使ＰＶＣ的玻璃化转变温度区域加宽，同时降低了ＬＬＤＰＥ组分的熔融热。共混体系中ＬＬＤＰＥ结晶动力学的测定结果表明，增容剂阻碍了ＬＬＤＰＥ相的结晶，使其结晶速度下降。动力学结果还表明，ＬＬＤＰＥ中不同结构的晶型分别按不同的Ａｖｒａｍｉ方程结晶，并同时受增容剂的影响。

It has been found that hydroogenated poly (butadiene-b-methyl methacrylate) copolymer is a good compatibillzer for PVC/LLDPE blends by using DSC to study the compatibility of the blends.The copolymer widen the width of Tg of PVC and reduce the melting heat (△Hf)of LLDPE. The results of crystalline dynamics for blends show that the copolymer prevents LLDPE from crystallizine and slows the rate of crystallizing. It can also be found that there are two kinds of crystalline process,and both of them are effected by the copolymer added in the blends.