Surface modification of EVA copolymer by UV treatment

The adhesion between a polychloroprene adhesive and an ethylene vinyl acetate copolymer containing 12 wt% vinyl acetate (EVA12) was improved by treatment with UV radiation. Changes in the EVA12 surface due to UV radiation treatment were assessed using contact angle measurements, ATR-IR spectroscopy, XPS, SEM and T-peel tests. Adhesion was evaluated from T-peel tests of treated EVA12/ polychloroprene adhesive +5 wt% polyisocyanate. Treatment of EVA12 with UV radiation increased its wettability, carbon-oxygen polar moieties were produced and roughness was created. As a consequence, adhesion of EVA12 to polychloroprene adhesive +5 wt% polyisocyanate was enhanced by treatment with UV radiation longer than 5 min. A mixed failure (mainly cohesive failure in EVA12) was obtained.