Photo-polymerized epoxy primer for adhesion improvement at thermoplastics/metallic wires interfaces

We report results on the development of an innovative fast-curing coupling method using a UV-curable epoxy primer based on a cycloaliphatic di-epoxide resin to bond metallic wires and a thermoplastic polyurethane matrix. The curing kinetics of the primer and its mechanical properties were analysed to optimize the formulation. Adhesion and durability were then tested by pull-out tests before and after hydrothermal ageing for several formulations and composites. The proposed UV-curable primer outperformed a conventional surface treatment and a thermally cured silane primer used for comparison in terms of processing time, adhesion and durability.