偶联剂在PVC塑料化学镀Ni-Cu-P前处理中的应用

Coupling agents, as the replacements of chromic acid for corsening in conventional electroless plating, were used to pretreat polyvinyl chloride (PVC) for electroless Ni-Cu-P plating so as to avoid the damage to environment and human body by the toxic chromic acid. Thus the pretreatment effects of silane coupling agents KH550 and KH560 and titanate ester-type coupling agent NTC-401 were investigated. The phase composition of the electroless Ni-Cu-P alloy coating on the surface of PVC after being treated with the silane coupling agents was analyzed by means of X-ray diffraction, while the adhesion of the alloy coating to the substrate was evaluated using scratch test and bending teat. Moreover, the morphology of the electroless Ni-Cu-P alloy coating was observed using a scanning electron microscope, and its elemental composition was determined using an energy dispersive spectrometer. It was found that the PVC plastic after being treated with silane coupling agent KH560 was strongly hydrophilic, and the corresponding electroless Ni-Cu-P alloy coating had amorphous structure and was well adhered to the substrate. The elemental composition (mass fraction) of the alloy coating was determined as 81.5% Ni, 15.3% Cu and 12% P.