Adhesion between poly(ethylene-co-vinyl alcohol) (EVA) and titanium

Abstract

Lap shear adhesive strength between titanium and various kinds of commercial polymers was evaluated. Among them, poly(ethylene-co-vinyl alcohol) (EVA) showed the highest strength. The results of electron spectroscopy for chemical analysis and the contact angle to water indicated that the high adhesive strength of EVA might be due to its high hydrophilicity. Water resistance of adhesion by water immersing at 37 degrees C was investigated. In the case of polyurethane-titanium, the adhesive strength decreased immediately. In contrast, EVA-titanium kept its initial adhesive strength for at least up to 1 month. It was confirmed that surface modification of titanium by hydrogen peroxide enhanced the adhesive and peeling strength. It was based on not only an increase in surface adhesive area but also an increase in the hydrophilicity of titanium by the production of Ti-OH.