UPPER CRITICAL SOLUTION TEMPERATURE (UCST) PHASE-BEHAVIOR AND PRESSURE-SENSITIVE ADHESIVE PROPERTIES IN BLENDS OF POLY(VINYL ETHYLENE-CO-1,4-BUTADIENE) WITH HYDROGENATED TERPENE RESIN

Pressure-sensitive adhesive (PSA) properties of blends of poly(vinyl ethylene-co-1,4-butadiene), V-BR, with hydrogenated terpene resin were examined using blend films prepared at 70 and 140-degrees-C. Since the blend has an upper critical solution temperature of approximately 133-degrees-C significant differences between PSA properties of miscible and immiscible blends were indicated. These differences were explained in terms of the dynamic mechanical behaviour. Cohesive failure of the adhesive layer was also discussed with reference to the surface tensions of the V-BR and the hydrogenated terpene resin, these parameters being estimated according to the Flory equation of state theory.