Composite Interfaces, Vol.14, No.2, 153-164, 2007
Rheology and mechanical properties enhancement of polymerization-filled polyethylene-based composites prepared with kaolin-supported metallocene catalyst
Polyethylene-based composites have been successfully prepared via in-situ ethylene polymerization with a metallocene catalyst previously deposited on the surface of kaolin particles. Molecular weight (M-w) of the polyethylene matrix has been estimated from intrinsic viscosity. The filler-matrix interfacial adhesion, rheological behavior, induced nucleation effect, and mechanical properties have been investigated in relation to kaolin filler content. Furthermore, these properties have been compared to those of the melt-mixed counterpart composites. As a rule, the polymerization-filled composites exhibit improved rheological behaviors and mechanical properties compared to the analogues prepared by melt mixing. The improved theological behaviors and mechanical properties of polymerization-filled polyethylene/kaolin composites are thought to result from the lessening of high elasticity of polyethylene melt, the nucleation of polyethylene crystallization, fine filler dispersion, and good filler-polymer interfacial adhesion. By contrast, the melt-mixed counterpart composites show no obvious enhancement of properties. The superiority of polymerization-filled polyethylene/kaolin composites over melt-mixed composites indicates the formation of good kaolin-polyethylene interfacial adhesion in polymerization-filled composites.