Interactions of electroless catalysts with photo-oxidized polymer surfaces

The surfaces of poly(styrene) (PS) and two polymers containing styrene, poly(styrene--acrylonitrile) (SAN), and poly(acrylonitrile--butadiene--styrene) (ABS) were photo-oxidized with 254 nm light and then treated with Pd- or Ag-based electroless catalysts. These photo-oxidized surfaces poisoned the Pd catalysts, hence inhibiting electroless metal plating, but the Ag-based catalyst resisted deactivation by the modified surface. Results from X-ray photoelectron spectroscopy (XPS) indicate that catalyst poisoning is due to photochemically produced carbonyl groups on the polymer surfaces, but show no spectroscopically significant change in the electroless catalysts. Treating irradiated polymers with alkaline solution restores platability and correlates with a loss of surface carbonyl groups by way of an alkaline decarbonylation reaction. Six electroless baths (two Cu and four Ni) were examined; the catalyst deactivation effect is independent of bath chemistry. Graphs. 32 ref.--AA