ADHESION TO ALUMINUM OF POLYMER BLENDS BASED ON ETHYLENE ACRYLIC-ACIDCOPOLYMERS (EAA)

The peel strength measured for polymer adhering to metal is the result of basic adhesion, and visco-elastic behaviour of the adhesive. In th is work, we are trying to determine the relative importance of both of these two terms. When decreasing the tensile strength (sigma Failure) of the polymers by increasing the temperature of the tests, a transit ion from adhesive to cohesive failure associated with a maximum in adh esion has been reported by many workers. We have modified the tensile strength of the adhesives by adding increasing amounts of a platicizer (paraffin) or another polymer. The same relationship between the tens ile strength and the adhesive behaviour of the polymers is observed fo r all kinds of blends used. With blends based on EAA containing 6, 11 or 15 wt% acrylic acid and paraffin or PS, we have observed a good lin ear relationship between the sigma Failure of the EAA/PS or EAA/paraff in blend with the best peeling strength and the acid amount of the EAA .