UHMWPE改性PP的结晶行为和亚微观形态研究

Crystal Behaviors and Microcosmic Patterns of PP/UHMWPE

本文采用DSC和扫描电镜研究了PP／UHMWPE的结晶行为及其亚微观形态结构。发现PP中的乙烯嵌段与UHMWPE具有良好的晶相相容性，生成了共晶；合金中乙烯链段和丙烯链段的结晶度随着UHMWPE掺混量的增加，总体分别呈上升和下降趋势，但结晶完善程度却基本无变化；混炼均匀的合金在较快的降温速率下UHMWPE先与PP结晶，并成为PP的成核剂，促使两组份同时结晶，结晶曲线呈现单峰；降温速率减慢后，出现两个结晶峰。电镜照片发现，合金冲击试样断面有大量UHMWPE形成的白色细点和细丝结构存在。结合结晶分析结果，认为UHMWPE在合金中形成了特殊的"物理交联网络"，并以此机理较全面地解释了UHMWPE对PP力学、流变等性能的影响。

The crystal behaviors and microcosmic patterns were studied by DSC and TEM for PP-1330/UHMWPE. It showed that the ethylene diblock of PP-1330 had good crystal phase compatibility with UHMWPE, and they formed cocrystal; With the rising of UHMWPE content in alloy, the crystallinity of PE part and PP part took on roughly increasing and decreasing trends respectively, but had little influence on the perfectibility of crystallization; At higher temperature decreasing rate, the well-distributed UHMWPE could be crystallized ahead of PP and became its nucleus making two composites crystalline simultaneously, so that the crystal curves all only took on one peak; but when the temperature decreasing rate was lowed to some degree, the crystal peak would be devided into two;The TEM photos showed that there were many small white spots and fine threads which were formed by UHMWPE on the sections of impact sample, combined with the results from crystallization could be concluded that a special 'physical crosslinked network' was formed in PP-1330/UHMPWE, and this structure could better explain the fluctuations of physical and rheological properties for UHMPWE modified PP-1330.