长玻纤增强PP材料界面行为对其力学性能的影响

Effect of Interfacial Behavior on Properties of Long Glass Fiber Reinforced PP

采用不同接枝率的马来酸酐接枝聚丙烯(PP-g-MAH)与长玻璃纤维(LGF)和聚丙烯(PP)共混制备PP/LGF复合材料。通过常温23℃条件下常规力学性能测试以及高温100℃、40 MPa条件下的拉伸蠕变测试研究PPg-MAH接枝率对PP/LGF复合材料性能的影响,利用扫描电子显微镜(SEM)对其中两个样品的高温拉伸蠕变失效样条断口位置LGF与PP基体之间的界面行为进行SEM组织分析。结果表明,用接枝率为1.6%的PP-g-MAH所制备的PP/LGF复合材料的性能最优,拉伸强度可以达到87 MPa,断裂伸长率可达到2.4%,相应的其高温拉伸蠕变性能最佳,蠕变断裂失效时间可以达到330 h。根据SEM分析结果,接枝率为1.6%的PP-g-MAH制备的PP/LGF复合材料中LGF与PP基体之间的界面行为表现更紧密。综合性能以及SEM分析,PP-g-MAH的接枝率在一定范围内对PP/LGF复合材料性能有正向影响,超过阈值后会起反作用;PP/LGF复合材料中LGF与PP基体之间界面行为紧密与否是影响材料性能的根本因素。

Long glass fiber reinforced polypropylene(PP/LGF)composites were prepared by maleic anhydride grafted polypropylene(PP-g-MAH),LGF and PP with different grafting rates.The influence of graft rate of PP-g-MAH on properties of PP/LGF composites were studied by conventional mechanical properties test at room temperature and tensile creep test at 100℃and 40 MPa.The microstructure of the interface between LGF and PP matrix at the fracture position of two samples of high temperature tensile creep failure spline was analyzed by scanning electron microscope(SEM).The results show that the PP/LGF composites prepared by PP-g-MAH with a graft rate of 1.6%has the best tensile strength of 87 MPa,elongation at break of 2.4%,corresponding to the best tensile creep performance at high temperature that the creep failure time can reach 330 h.According to the microstructure analysis results of SEM,the interfacial behavior between LGF and PP matrix in PP/LGF composites prepared by PP-g-MAH with grafting rate of 1.6%is closer.The comprehensive property analysis and SEM analysis show that the graft rate of PP-g-MAH has a positive effect on the properties of PP/LGF composites within a certain range,and has a negative effect when the graft rate exceeded the threshold value.The fundamental factor that affects the properties of PP/LGF composites is the interfacial behavior between LGF and PP matrix.