Polyethylene toughened by rigid inorganic particles

High density polyethylene (HDPE) is toughened by particles of rigid inorganic filler CaCO3, which is treated with phosphate. The stress-strain curve of the HDPE/modified-CaCO3 (80/20) composite covers a greater area than that of HDPE, and the impact strength of HDPE is greatly improved by modified CaCO3 from 230 J/m to 580 J/m as CaCO3 content is increased to 50 wt%. Morphological observation indicates a finer dispersion of the modified-CaCO3 particles and a large plastic deformation of HDPE. The cavitation and stress field interaction around the particles are considered to explain the toughening mechanism.