The present paper describes a novel method for reinforcing isotactic polypropylene (PP) by adding poly(vinyl alcohol) (PVA) fibers prepared by melt-stretching. Low-viscosity PVA droplets were deformed into fibers in the molten PP by melt-stretching them beyond the melting point of PVA. When the obtained composite was extruded below the melting point of PVA, the fibers became oriented toward the flow direction. The PVA demonstrated marked nucleating activity with regard to PP crystallization, which was further promoted by enlargement of the surface area by fibrillization. As a result, there was virtually no orientation relaxation of the PP chains with an increase in crystallinity, which explains the improvement in rigidity of the reinforced composite.

本文介绍了一种通过添加熔融拉伸制备的聚乙烯醇 (PVA) 纤维来增强全同立构聚丙烯 (PP) 的新方法。低粘度 PVA 液滴通过将其熔融拉伸至 PVA 熔点以上而变形为熔融 PP 中的纤维。当所得复合材料在低于 PVA 熔点的温度下挤出时，纤维变得朝向流动方向取向。PVA 在 PP 结晶方面表现出显着的成核活性，通过原纤化扩大表面积进一步促进了这种成核活性。结果，随着结晶度的增加，PP链几乎没有取向松弛，这解释了增强复合材料刚性的提高。