Effects of pressure and temperature on the melt density and the melt flow rate of LDEP and glass bead-filled LDPE composite

The effects of pressure and temperature on the melt density (rho(m)) and the melt flow rate (MFR) of the low-density polyethylene (LDPE) and a glass bead-filled LDPE composite (LDPE/GB) have been investigated using a capillary plastometer. It was discovered that the MFR of the melts increased as an exponential law function with a rise in temperatures and increased as a quadratic function with increasing pressure; the rho(m) of the melts increases non-linearly with increases in pressure and decreased approximately linearly with increases in temperature. For the same temperature, the values of the MFR for LDPE/GB are somewhat lower than those of the unfilled LDPE when the pressure is not too high. The relationship between the composite melt density, the glass bead density and the unfilled LDPE melt density obeys a simple mixing rule. (C) 1998 Elsevier Science S.A. All rights reserved.