Abstract
Bovine tanned leather without a finish was treated with a one-component urethane prepolymer primer. The changes produced in the leather by increasing the time between the application of the primer and the adhesive joint formation (reaction time) were analyzed by IR-ATR spectroscopy, DMTA, and stress–strain measurements. Adhesion was tested in terms of T-peel strength of PVC/polyurethane adhesive/leather joints. By increasing the reaction time, a higher degree of primer curing was obtained and a higher cohesion was achieved in the leather (i.e., increased mechanical properties). Higher initial and final adhesion values for the primed leather to polyurethane adhesive were obtained by increasing the reaction time, and a higher joint strength was always obtained in comparison to that obtained in the adhesive joint produced with the roughened unprimed leather. Therefore, the application of a urethane-based primer was a good alternative to the current roughening treatment of leather for improving the upper leather to sole bonding in shoe manufacturing.