分子量对PP／UHMWPE合金的力学性能、形态和流变行为的影响

EFFECT OF MOLECULAR WEIGHT ON MECHANICAL,MORPHOLOGICAL AND RHEOLOGICAL PROPERTIES OF PP/UHMWPE BLENDS

用分子量分别为１．２×１０￣６、２．５×１０￣６和３．５×１０￣６的ＵＨＭＷＰＥ与ＰＰ共混制成合金，并对这些合金的力学性能、亚微形态和流变行为进行了研究。发现ＰＰ／ＵＨＭＷＰＥ合金的力学性能对ＵＨＭＷＰＥ的分子量有较大的依赖性，ＵＨＭＷＰＥ的分子量越高，则合金的Ｉｚｏｄ冲击强度、拉伸强度、弯曲强度和弯曲模量也越高。用ＳＥＭ对冲击样条的断裂形貌研究表明，当ＵＨＭＷＰＥ的分子量高于２．５×１０￣６后，合金的断裂行为完全不同于分子量为１．２×１０￣６的ＵＨＭＷＰＥ与ＰＰ合金，前者呈典型的延性断裂。此外，ＵＨＭＷＰＥ的分子量对ＰＰ／ＵＨＭＷＰＥ合金的流变性能也有一定的影响，而这种影响正是由于不同分子量的ＵＨＭＷＰＥ在合金中形态结构的差异所致。

In this study,the blends of PP and UHMWPE with molecular weight of 1.2×10￣6,2.5×10￣6, 3.5×10￣6 were prepared, and the mechanical properties,morphology and rheological behavior were investigated,It is found that the molecular weight of UHMWPE affects the mechanical properties of PP/UHMWPE blends greatly. The higher the molecular weight,the better Ized impact strength,tensile strength, flexural strength and flexural modulus.The fracture behavior of blends of PP/UHMWPE (M_n=2.5×10￣6 and 3.5×10￣6) is different from that of PP/UHMWPE (M_n=1.2×10￣6)completely,and the former is shown toughness,It is the morphology of UHMWPE with different molecular weight in PP mixtra that has a influence on rheological properties of blends of PP/UHMWPE.