TOUGHENING AND STIFFENING EFFECTS OF T-ZnOw WHISKERS ON POLYSTYRENE

The main subject of this work is about the effect of T-ZnOw on the toughness and stiffness of polystyrene (PS). In order to avoid the rupture of T-ZnOw during the melt processing, T-ZnOw/PS composites were obtained via the combination of solution blending and injection moulding methods. Although the tensile strength of the composites decreases slightly, the impact strength and tensile modulus increase with the increase of the T-ZnOw content in the matrix. The stiffness and toughness of the composites are enhanced simultaneously. SEM results of the impact-fractured surface show more polymer avulsions, ridges and micro-cracks formed in the T-ZnOw/PS composites, companied with pullout of T-ZnOw from PS matrix and local yielding of PS matrix around T-ZnOw during the impact processing. The possible reasons for the toughness increment of T-ZnOw/PS composites are attributed to the interracial debonding, pullout of T-ZnOw from PS matrix,anchoring effect of T-ZnOw's special three dimensional structure, local yielding of PS matrix and the formation and propagation of micro-cracks.