短玻纤增强聚丙烯注射压力对微观结构和力学性能影响

报道了短玻纤增强聚丙烯复合材料中玻纤及注射压力对材料微观结构和力学性能的影响规律。实验结果表明: 随着玻纤含量提高, 复合材料的拉伸强度提高, 而断裂伸长率、冲击强度和熔体流动速率则下降。注射压力提高, 拉伸试样芯层中玻纤的平均取向角下降, 取向度提高, 因而拉伸强度增大, 冲击强度下降。皮层结构中玻纤沿熔体流动方向高度取向。聚丙烯球晶尺寸随玻纤含量增加而变小, 规整度也变差, 至40% 时, 聚丙烯已难以形成规整的球晶结构。

EFFECTS OF INJECTION PRESSURE ON THE MICROSTRUCTURES AND MECHANICAL PROPERTIES OF SHORT GLASS FIBER INJECTION-MOULDED REINFORCED POLYPROPYLENE

The paper reported the effects of short glass fiber(GF) content and injection pressure on the microstructures and mechanical properties of GF/PP composites.Experimental results showed that the tensile strength was improved, but the impact strength, break elongation and melt flow rate (MFR) decreased with increasing of glass fiber content in GF/PP composites.Orientation degree of GF in core layer was promoted with increase of injection pressure, but the orientation degree of GF in skin layer was parallel to the melt flow direction(MFD) by metallographic optical microscopy and SEM.The crystalizing ability of polypropylene in GF/PP composite went down with increase of GF content by polarization microscopy.