Electroless nickel plating on polypropylene via hydrophilic modification and supercritical carbon dioxide Pd-complex infusion

► ScCO2-assisted electroless Ni-P plating could be applied to PP-based substrate. ► Hydrophilicity of PP was modified by blending PP with a PP-b-PEO copolymer. ► Adhesiveness of metal film to polymer substrate was increased by thickening the metal/polymer composite layer. ► The thickness of composite layer was determined by the competitive relationship between the diffusion rate of plating solution in polymer substrate and the rate of plating reaction.