Crystallization temperature effect on the solid-state rheology of a high-density polyethylene under compression

The plane‐strain compression test provides quantitative data on the polymer rheology in homonogeneous large deformation at constant strain‐rate, and on the friction shear stress between the film and the dies. Thin HDPE films with a homogeneous morphology were formed by quenching or isothermal crystallization. The structure was modified by varying the crystallization temperature over a wide range: 118°C ⩽ Tc ⩽ 130°C. A mechanical model with a pressure‐dependent rheology and two friction laws was tested. The rheological parameters are different in tension and in compression. The occurrence of brittle fracture under compression depends on the crystallization temperature, but the rheological parameters are almost independent of the crystallization conditions.