PREPARATION AND CHARACTERIZATION OF PERLITE-FILLED HIGH-DENSITY POLYETHYLENES .1. MECHANICAL-PROPERTIES

Four different types of high-density polyethylenes (HDPE) were blended with perlite at different concentrations. Silane coupling agent gamma -aminopropyltriethoxy silane (gamma-APS, A-1100) was used to enhance t he adhesion between perlite and HDPEs. Ultimate tensile strength and e lastic modulus increased as the perlite content increased, while ultim ate elongations decreased with the increasing amount of perlite. Excep tional variations in the measured properties are explained in terms of the differences in polyethylenes used in the composites. The biggest improvement in ultimate tensile strength was observed in the highly cr ystalline polyethylene; on the other hand, in the absence of silane co upling agent the high molecular weight polyethylene showed the least i mprovement in tensile strength. The effect of branching in HDPE compos ites was demonstrated. The enhancement of interfacial adhesion by usin g a coupling agent was also examined by scanning electron microscopy ( SEM). (C) 1994 John Wiley and Sons, Inc.