Effect of a polystyrene-polyisoprene diblock layer on the adhesion between polystyrene and polyisoprene

The adhesion between polystyrene and crosslinked polyisoprene homopolymers was found to be increased by the presence of a thin layer of polystyrene-polyisoprene block copolymer at the interface. The interfacial toughness was a function of both the layer thickness and molecular weight of the copolymer. If the homopolyisoprene was crosslinked before the joint was made, the joint failed at a relatively low toughness by the polyisoprene of the diblock pulling out of the polyisoprene homopolymer. Joints that failed by pull-out could be reformed by contact at room temperature. A high degree of interfacial toughness was found when the homopolymer and copolymer polyisoprene were crosslinked together. © 1993.