Morphologies and mechanical properties of syndiotactic polypropylene (sPP)/ polyethylene (PE) blends

The tensile properties of blends based on syndiotactic polypropylene (sPP) and high-density polyethylene (HDPE) have been studied. In order to underst and the unexpected decrease in ductility, the crystallization behavior of t hese blends was characterized by transmission electron microscopy and in-si tu Raman spectroscopy. For all investigated blends demixing occurs, and res ults for low HDPE concentrations in an island-like morphology of HDPE domai ns embedded in a continuous sPP matrix. For all investigated sPP/HDPE blend s the start temperature of the sPP crystallization significantly increases with increasing HDPE content. (C) 1999 Elsevier Science Ltd. All rights res erved.