Polyethylene toughened by CaCO3 particles-percolation model of Brittle-Ductile transition in HDPE/CaCO3 blends

The percolation model is used to interpret the brittle-ductile transition of HDPE/CaCO3 blends. The percolation threshold (θsc) for HDPE/CaCO3 blends is found to be 0.52, which is equal to π/6. The critical exponent (g) is found to be 0.83 for HDPE/CaCO3 blends. The toughening efficiency of blends which have monodisperse, highly asymmetrical particles, strong interphase adhesion and high matrix toughness is greater. The brittle-ductile transition in polymer blends seems to be a universal percolation phenomenon.