滑石粉/聚丙烯复合材料结晶度与相间形态对其力学性能的影响

用偶联剂改性的滑石粉（Talc）与聚丙烯（PP）共混制备Talc／PP复合材料，测试了复合材料的力学性能。用广角X射线衍射仪对聚丙烯的结晶状况进行了表征，计算了复合材料中聚丙烯的结晶度；用扫描电镜观察了样条的断口形貌，讨论了滑石粉填充量对材料结晶性能与相态结构的影响．以及PP相结晶度和体系的微相结构对复合材料的拉伸、弯曲及冲击性能的影响。实验结果表明，滑石粉的加入对复合材料的结晶行为、相态结构和力学性能有影响。在15％的滑石粉填充量时，聚丙烯相的结晶度达到最大值，材料的拉伸强度、弯曲强度也基本上达到最大值，而冲击强度却降到最低。扫描电镜照片显示，PP基体的结晶形态与复合材料的相态结构随滑石粉含量的改变而变化。

INVESTIGATION ON CRYSTALLINITY AND MORPHOLOGY OF ULTRAFINE TALC-FILLED POLYPROPYLENE COMPOSITES AND THEIR INFLUENCE ON ITS MECHANICAL PROPERTIES

The Polypropylene (PP)-matrix composites filled with ultrafine talc pre-treated by coupling agent have been prepared in this research. Mechanical properties, crystal and morphology properties of composites were examined. The Wide-angle X-ray Diffraction (WAXD) was used to analyze of crystal property of PP phase and the crystallinities of PP phase were calculated in variant talc content composites. The scanning electron microscope (SEM) was used to examine the structure of the fracture surface and to justify the variation of the measured mechanical properties. Influences of talc content on the morphology and crystal properties of composites were analyzed. The influences of talc content and morphology property on tensile, flexural and impact properties of Talc/PP composites were compared. Experimental results indicate that the addition of talc influences the crystallization, morphology and mechanical properties of Talc/PP composites. Moreover, when the talc content is increasing from 0-25%, the crystallinity of PP phase reaches a maximum at the 15% content of talc, and the tensile, flexural strength of Talc/PP composites gets the maximum too, but the impact strength declines to the lowest. SEM photographs of impact fracture surfaces indicate the crystal conformation of PP matrix and the phase structure of composites varies with the content of Talc in the Talc/PP composites.