Some aspects of surface deformation and fracture of 5–20% calcium carbonate-reinforced polyethylene composites

The paper describes the surface deformation and fracture process during tensile straining of 5–20% calcium carbonate-reinforced polyethylene composites and compares the behavior with unreinforced neat polyethylene as a function of strain rate of tensile test. Calcium carbonate-reinforced polyethylene composites exhibit increased tensile modulus in comparison to neat polyethylene, while the influence on yield strength is not clearly discernible. Calcium carbonate reinforcement reduces the extent of cold drawing of the polymer matrix. The primary surface deformation process of crazing-tearing and fibrillation in unreinforced neat polyethylene is altered to ridge/wedge tearing in calcium carbonate-reinforced polyethylene composites. The mode of fracture in neat polyethylene is crazing-tearing and fibrillation, while in calcium carbonate-reinforced composites, the mode of fracture is fibrillation. However, the nature of fibrillation (layered or non-layered) depends on percent reinforcement and strain rate of tensile test. High strain rate and high percent reinforcement favors predominantly layered fibrillation in calcium carbonate-reinforced polyethylene composites.