Toughening and reinforcement of HDPE/CaCO3 blends by interfacial modification interfacial interaction

To improve the mechanical properties and structure of HDPE/CaCO3 composites, a type of modifier, consisting mainly of carboxylated polyethylene (CPE), and a type of CaCO3 grafted with acrylamide (CaCO3-A) were used. The carboxyl group content of CPE was from 1 to 10%. The amide group content on the surface of the modified CaCO3 was from 0.2 to 1.8%. The interfacial structure and interaction of ternary blends of HDPE, CPE, and CaCO3-A were studied. The results indicate that the higher the amide group content and the carboxyl group content, the higher the tensile and impact strength. This behavior has been attributed to a series of chemical and physico-chemical interactions taking place between the two components during the blending process which were confirmed by FTIR and extraction experiments. The improvement of interfacial adhesion by the CPE and CaCO3-A was also clearly revealed in the SEM of the fracture surface. (C) 1997 John Wiley & Sons, Inc.