A New Brittleness Criterion for Low Density Polyethylene Films

Abstract Since the existing methods of establishing brittleness criteria for low density polyethylene films were found to be unsatisfactory, the present study was undertaken to investigate the brittle-ductile transition and the factors that may influence it. By defining a brittle failure under uniaxial constant strain rate test conditions, a transition temperature from ductile to brittle failure was established at each strain rate. It was found that at low strain rates the transition temperature is almost independent of the strain rate. This temperature is suggested as the cold brittleness temperature. This cold brittleness temperature is related to the energy dissipation ability of the material as found from dynamic mechanical tests. The correlation between the uniaxial constant strain rate test and the dynamic mechanical data was checked mathematically by using a viscoelastic model.