UV-curable epoxy primer for adhesion between metallic oxides and thermoplastic polyurethane

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. The materials to bond are metallic wires and a thermoplastic polyurethane matrix. The curing kinetics of the primer and its mechanical properties were analysed by photo-DSC and photo-rheology to optimize the formulation. Adhesion and durability were then tested by pull-out tests before and after hydrothermal aging for several formulations and processing parameters. 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.