嵌段共聚物对LDPE/PS共混物性能和形态的影响

EFFECTS OF BLOCK COPOLYMER ON THE PROPERTIES AND MORPHOLOGY OF LDPE/PS BLENDS

研究了二嵌段共聚物（ＳＢ）和不同分子量的三嵌段共聚物（ＳＥＢＳ）对ＬＤＰＥ／ＰＳ共混物的应力～应变行为、冲击强度和形态结构的影响。结果表明，加入增容剂后，共混物的拉伸强度和冲击强度都得到改善，动态力学谱显示ＬＤＰＥ的α转变峰Ａ随着增容剂含量的增加，峰的宽度增大，峰位逐渐向高温方向位移。当含量达到５％左右，转变峰Ａ的位移达到最大值，继续增加增容剂的含量，转变峰Ａ逐渐向低温方向位移。透射电镜观察显示分子量大的ＳＥＢＳ在均聚物中形成微束。并讨论了嵌段共聚物分子量对共混物的增容效果。

The effects of diblock copolymer(SB) and triblock copolymer(SEBS) with different molecular weight on the stress-strain behavior, impact strength and morphology were studied. A reduction on phase size was observed, and tensile strength and impact strength were improved by adding compatibilizers. Dynamic mechanical spectra shown that α transition temperature of LDPE increases and the width of the peak become broader as the concentration of compatibilizers increasing up to 5%. The α transition temperature starts to decrease for more than 5%. SEBS with higher molecular weight is found to become micellae in homopolymer LDPE. Compatibilization effeciency and morphological considerations influencing the blend′s properties were discussed.