A low pollution surface pretreatment of PC-ABS under acidic conditions

In the present study, the low pollution acidic potassium permanganate system has been used in the study of its micro-etching effect on polycarbonate-acrylonitrile butadiene styrene (PC-ABS). Prior to micro-etching using a N methyl pyrrolidone (NMP)-glycol butyl ether solution was used as the swelling system of PC-ABS. Reasonable swelling conditions were determined, a 2-min expansion period at a temperature of 35 degrees C with an NMP concentration of 80%. After the swelling processes, the effects of the volume ratio of VH2O:VH2SO4, micro-etching temperature, and micro-etching duration on the PC-ABS surface morphology, surface roughness, surface hydrophilicity, and peel strength, have been investigated. It was finally determined that the best micro-etching effect could be obtained by reacting at VH2O:VH2SO4 = 1:2 and a temperature of 60 degrees C for 25 min. The surface of the PC-ABS copolymers was characterized by x-ray photoelectron spectroscopy, atomic force microscopy, and Fourier-transform infrared spectroscopy. The results showed that the micro-etching process changed the morphology of the PC-ABS surface and generated cavities. In addition, the surface roughness increased from the initial R-a = 9.69 to R-a = 197 nm. Also, the water contact angle on the PC-ABS surface decreased from 92.2 degrees to 28.6 degrees, and the peel strength increased to 0.98 kN/m.