长纤维增强PP复合材料的制备与性能研究

摘要

通过开炼–模压成型工艺方法，制备了长玻璃纤维(LGF)增强聚丙烯(PP)复合材料，首先研究了β成核剂对纯PP力学性能和结晶性能的影响，在此基础上研究了LGF对PP／LGF复合材料力学、结晶性能及热稳定性的影响，最后探讨了增容剂马来酸酐接枝三元乙丙橡胶(EPDM-g-MAH)对复合材料力学性能的影响。结果表明，β成核剂可以改善PP的冲击韧性，但降低了PP的拉伸和弯曲强度，当β成核剂质量分数为0.2%时，PP的综合性能最好；随LGF含量增加，PP／LGF复合材料的拉伸、弯曲和冲击强度及结晶度总体上呈先增大后减小的趋势，不同LGF含量下的复合材料起始热分解温度均在390℃以上，当LGF质量分数为20%时，复合材料的综合性能最好；少量的EPDM-g-MAH能改善LGF与PP基体的界面相容性，大幅增强了复合材料的韧性，其最适宜的质量分数为10%。%Longfiber (LGF) reinforced polypropylene (PP) composites were prepared using mixing and compression molding. First,the effects ofβ-nucleating agent on the mechanical and crystallization properties of PP were studied,on the basis,the influ-ences of LGF on the mechanical,crystallization properties and thermal stability of PP/LGF composites were investigated,at last, the effects of compatilizer EPDM-g-MAH on the mechanical properties of the composites were discussed. The results indicate thatβ-nucleating agent can improve the toughness of PP,but the tensile and bending strength are decreased,when the mass fraction ofβ-nucleating agent is 0.2%, PP gains the optimum comprehensive performances. With increasing LGF content,the tensile,bend-ing,impact strength and crystallinity of PP/LGF compositesfirst increase and then decrease as a whole. The initial thermal decom-position temperatures of PP/LGF composites with different LGF content are above 390℃. When the mass fraction of LGF is 20%, PP/LGF composite shows the optimum performances. A few EPDM-g-MAH can effectively improve the interfacial compatibility between LGF and PP matrix,so the impacttoughness of the composite is greatly enhanced,the optimum mass fraction of EPDM-g-MAH is 10%.