Effects of Donut-Shaped ZnO Decorated UHMWPE Fibers on the Mechanical Properties of Rigid Polyurethane-Based Composites

Fiber-reinforced composites with excellent mechanical performances usually have a good interface property between fibers and the matrix to achieve effective load transfer. In this paper, structure decorations on the ultrahigh molecular-weight polyethylene (UHMWPE) fiber surface were explored to enhance the interface properties between fibers and the rigid polyurethane (RPU) matrix. Donut-shaped zinc oxide (D-ZnO) crystals grew on the fiber surface, and the morphologic and structural changes were characterized. The possible growth mechanisms of D-ZnO were discussed. The mechanical performances of UHMWPE fibers and corresponding composites were tested. The tensile strength of D-ZnO-UHMWPE fibers/RPU exhibited a remarkably 127.9% increase relative to pure RPU, and the impact toughness was increased by 155.2%. The investigations demonstrated that the decoration of D-ZnO could enhance the mechanical performances of the composites effectively. Moreover, further analysis indicated that adding D-ZnO-UHMWPE fibers to the RPU matrix provided more crack expansion paths, which improved the toughness of the composites.