Correlation between phase structure and mechanical anisotropy of PP/PS polymer blends

Abstract

Thermoplastics are lightweight materials with excellent moldability and are used in a wide range of applications, from everyday life to the automotive industry. Among them, melt molding is a process in which thermoplastics are melted to form a desired shape, then cooled and solidified. Molded products produced by this molding process exhibit anisotropic (directional) mechanical properties due to molecular orientation. The anisotropy is particularly pronounced when several plastic materials, called polymer blends, are mixed together, and it is known that the morphology of the mixed phase has a significant effect on the mechanical properties. However, it is difficult to quantitatively evaluate the mechanical anisotropy of polymer blend molded products using conventional evaluation methods, and the development of new evaluation methods is required. Against this background, this study aims to quantitatively evaluate the mechanical anisotropy in injection molded polymer blend products using a test method called the short-beam test and to clarify its significance.The short beam shear test is a method of measuring mechanical properties by applying a bending load to a small specimen. The data obtained from this test is expected to be analyzed to elucidate the mechanism of anisotropy in polymer blend molded products. Specifically, the degree and direction of anisotropy in mechanical properties can be quantified, providing useful information for optimizing material design and manufacturing processes. This research is expected to improve our understanding of anisotropy in polymer blend molded products and contribute to the development of higher performance products and the promotion of sustainable use of plastics.