制备长玻纤增强聚丙烯复合材料的熔融浸渍过程分析

以玻璃纤维/聚丙烯为研究对象，建立热塑性熔融树脂浸渍纤维的理论模型，模型表征在实验过程中不同加工工艺条件、熔体黏度以及纤维结构对树脂完全浸渍纤维束所需时间的影响，同时探讨了相关机理。树脂浸渍纤维的程度通过所制试样的层间剪切强度来表征，并通过扫描电镜对预浸带界面进行研究，结果表明：纤维束在浸渍机头中的停留时间、浸渍机头的温度、纤维束展宽以及选择不同的树脂基体，均将影响树脂与纤维两相间的界面结合，并最终影响材料的力学性能；树脂基体中添加相容剂马来酸酐接枝聚丙烯（PP-g-MAH）在玻璃纤维和树脂基体两相间能够起到交联作用，明显提高两相间的界面结合强度，使得复合材料的力学性能优于未添加PP-g-MAH的试样，但在基体中添加过多的PP-g-MAH，试样的力学性能则表现出下降的趋势。

Analysis of the impregnation process in the preparation of long glass fiber reinforced polypropylene composites

Using glass fiber and polypropylene, a mathematical model of the thermoplastic resin impregnation of the fibers in the molten state has been established and the relevant mechanisms are discussed. The model revealed that the time needed for complete impregnation of the fibers is affected by the processing conditions, melt viscosity and fiber structure. The interlaminar shear strength (ILSS) of specimens indicated the extent of impregnation of the fibers, and the interfacial bonding state was investigated by scanning electron microscopy (SEM). Long glass fiber reinforced polypropylene prepregs were prepared using a self-made melt impregnation device, and standard specimens were prepared by compression molding. The results showed that the ILSS, as well as the interfacial bonding, is affected by the residence time of fibers in the device, the temperature of the device, the breadth of the fiber bundle and the nature of the resin. Furthermore the addition of a compatibilizer, maleic acid grafted polypropylene (PP-g-MAH), enhanced the interfacial bonding between glass fiber and polypropylene, giving materials with mechanical properties superior to those of materials prepared without addition of PP-g-MAH. However, addition of exess PP-g-MAH had an adverse effect on the mechanical properties of the materials.