Adhesion of semi-crystalline polymers: shear contribution to fracture energy

A study of the adhesion of two semi-crystalline polymers (EVOH and PEg (grafted polyethylene)) by peel has shown that local fracture energy, GA, is virtually independent of peel angle. Adopting the Dugdale model for energy expenditure, we obtain an estimate of GAD of the order of magnitude of GA. However, observation of fracture fronts suggests that supplementary energy losses occur after separation, due to shear stresses reorienting the fibrillar craze material. A simple model is proposed to estimate this shear contribution to fracture energy, GAS, suggesting the potential importance of shear effects in overall fracture energy. To cite this article: A. Guiu, M.E.R. Shanahan, C. R. Physique 3 (2002) 397–402.