MORPHOLOGY AND PROPERTIES OF HDPE ZINC-NEUTRALIZED SULFONATED EPDM BLENDS

The compatibility of zinc-neutralized sulfonated EPDM (Zn-SEPDM) and its effect on crystallizing behavior of high-density polyethylene (HDPE) as well as the morphology of the blend were studied through wide-angle X-ray diffractomer (WAXD), differential scanning calorimetry (DSC), transition electron micrography (TEM), scanning electron micrography (SEM), a capillary rheometer, and mechanical property test. The results show that addition of Zn-SEPDM decreases both the melting point and the crystallizing temperature of HDPE. The apparent viscosity of the blend decreases with increasing of shear rate and stress. As Zn-SEPDM content exceeds 20%, Zn-SEPDM in the blend becomes continuous and an abrupt change in impact strength occurs. Owing to the incorporation of ionic groups into EPDM, the strong interactions between the chains make the impact strength of HDPE incredibly increased without sacrificing much of its tensile strength.