Adhesion improvement of an acrylic-urethane coating on PP-EPDM bumper by mediated electrochemical oxidation

The surface of PP-EPDM bumper in automotive industry suffers from poor adhesion to its coating, despite surface modification. In this work the effect of surface electrochemical modification by Ag (II) ions on the bumper surface was investigated and the results were compared to those of the untreated and flame-treated samples. The results of pull-off test showed that electrochemical treatment by Ag (II) can improve the bumper surface properties in comparison with the conventional flame-treatment technique by 20.7%. Accelerated UV weathering analysis along with SEM photography approved the effectiveness of the mediated electrochemical treatment by Ag (II) in long term particularly at curvature and low access area of the bumper.