Adhesion in polymer/steel sandwiches

Polymer/steel sandwiches are able to reduce the nuisance due to vibrations and noise in automotive applications, for example. Thin layers of polymer are inserted between two metal sheets. The deformation of the polymer is responsible for the damping properties of the sandwiches and, therefore, the viscoelastic behavior of the polymer is of major importance. However, adhesion between the two materials is also required. The polymer studied in the present work is a copolymer of ethylene and vinyl acetate (EVA) containing 28 wt% of vinyl acetate grafted with maleic anhydride (1 wt%). A wedge test is used to measure the interfacial strength and the durability of the adhesive bond. The influence of the surface treatment of the steel substrate on the adhesive behavior and the effect of water has been studied. FTIR surface analysis after cleavage helped us to identify the nature of the interfacial bonds.