Evaluation of coating rate and adhesive force for copper deposition on the surface of polypropylene

In spite of the metal-coated nonconductive materials have been widely used in many purposes, the coating rate and adhesive force of a metal to nonconductive material need to be evaluated. This study aims to investigate the effects of NaOH, CuSO4, HCHO and immersion time on coating rate and adhesive strength of CuO coatings on the polypropylene surface. The results showed that the coating rate of CuO deposition strongly affected by NaOH but weakly affected by CuSO4 in electroless solution. The addition of HCHO from 0.0136 to 0.0642 M in electroless solution can lead to the increased coating rate from 3.84 to 41.82 μm/h; however, the increase of coating rate is almost constant when the concentration of HCHO reaches more than 0.0642 M. The increase of either CuSO4 concentration or immersion time leads to an increased peeling force of CuO coated on the surface of polypropylene. An optimum adhesive thickness on the bond strength of CuO with the surface of polypropylene can be obtained when the polypropylene sample was immersed in the electroless solution containing 0.0187 M CuSO4 for 34.10 min. The research findings contribute to advance understanding of many variables affected adhesion strength between CuO and polypropylene.