Enhanced interfacial interaction of basalt fiber/PP composites by in-situ grown ZnO nanorods: preparation, structure, property and mechanistic study

Basalt fiber (BF) is a new type of environmentally friendly high-performance fiber, but the smooth and chemically inert surface limits its practical application. In order to increase the interfacial interaction of the BF based composites, ZnO nanorods were in-situ grown on the BF by hydrothermal method. Polymer composites based on polypropylene (PP) and modified BF were prepared by melt blending and micro injection molding. The structure and properties of the composites were investigated in detail and a three-dimensional representative volume element (RVE) model was applied to verify the effect of ZnO nanorods on the interfacial failure behavior of the composites. The results showed that the growth of ZnO nanorods increased the transverse strain of interfacial debonding and altered the damage pattern of the composites. Specifically, the rod-like ZnO enhanced the surface roughness and specific surface area of BF, produced higher shear force during micro injection molding process, caused more physical interlock and entanglement in the composites. As the result, the interface thickness, crystallinity and crystal orientation were increased. Consequently, the mechanical strength of the composites improved.