A study on reactive enhancement of filler-filled high-density polyethylene

The effects of reactive compatibilization on morphology, mechanical properties, rheological behavior, and dynamically mechanical behavior of high-density polyethylene (HDPE)/CaCO3, HDPE/STC (a mixture of sericit, tridymite, and cristobalite), and HDPE/illite were studied through scanning electron microscopy, DMTA, and mechanical and melt rheological properties tests. The experimental results show that the presence of a small amount of ethylene-acrylic acid copolymer (EAA) results in a large increase of yield strength of HDPE/CaCO3, HDPE/STC, and HDPE/illite and a slight increase of their viscosity, as well as enhancement of the gamma relaxation peak of HDPE and corresponding temperature shifts to higher temperature. The yield strength and impact strength of HDPE/illite (80/20) increase by 18% and 160%, respectively, in the presence of 1 wt% EAA. These are due to the interface enhancement of HDPE/fillers through the reaction of the carboxylic acid group in EAA with fillers.