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

The effects of reactive compatibilization on morphology, mechanical propert ies, rheological behavior, and dynamically mechanical behavior of high-dens ity polyethylene (HDPE)/CaCO3, HDPE/STC (a mixture of sericit, tridymite, a nd cristobalite), and HDPE/illite were studied through scanning electron mi croscopy, DMTA, and mechanical and melt rheological properties tests. The e xperimental results show that the presence of a small amount of ethylene-ac rylic 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 visco sity, as well as enhancement of the gamma relaxation peak of HDPE and corre sponding temperature shifts to higher temperature. The yield strength and i mpact strength of HDPE/illite (80/20) increase by 18% and 160%, respectivel y, 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 w ith fillers.