Adhesive bonding of polyvinylidene fluoride: Effect of curing agent in PVF2 surface modification

—We have shown that certain amine and amide curing agents for epoxy resins modify the surface properties of the fluoropolymer polyvinylidene fluoride (PVF2), thereby permitting the formation of strong adhesive joints. When PVF2 is exposed to these curing agents at the temperatures used in preparing adhesive joints (~70°C), discoloration (darkening) occurs with concomitant gelation. This suggests that there is dehydrofluorination followed by crosslinking. Infrared spectroscopy has been used to follow the course of these reactions. In effect, the curing agent serves a dual function. It reacts with the fluoropolymer both to modify the surface region and to crosslink the epoxy resin.