Durability of steel/polymer adhesion in an aqueous environment

Abstract In this work, the durability of steel/polymer/steel assemblies in various liquids (water, salt, acid and basic solutions) is studied. Two steel substrates are compared: one without any surface treatment and the other one with a phosphatizing surface treatment. The polymer is an ethylene–vinyl acetate copolymer (EVA) grafted with maleic anhydride. The wedge test is used in order to quantify the steel/polymer adherence before and during ageing. The results show that a rapid delamination is observed for the non-treated steel/EVA assemblies in all the studied liquid. A cathodic delamination process is proposed to explain the delamination mechanism. A good ageing resistance is observed for the phosphatized steel/EVA assemblies, not only due to the corrosion resistance of the steel substrate but also due to the insensibility of the interfacial steel/polymer bonds of the studied liquids.