POLY(2-ALLYL)PHENYLENE OXIDE ELECTROPOLYMER FILMS AS AN ADHESION-ENHANCING TREATMENT FOR STEEL

The enhancement of metal-polymer adhesion via thin reactive electropol ymer films of poly(2-allyl)phenylene oxide was studied using adhesive joint failure techniques. Thin (0.2-0.4 micron) films were formed on s teel blocks using potentiostatic electrooxidation. Two blocks were cem ented together to form adhesive joint specimens using an unsaturated p olyester/styrene resin system. Adhesive joint specimens were also form ed from both untreated blocks and treated blocks where the allyl funct ionality of the electropolymer was destroyed by heat crosslinking. Fai lure energies were then determined for joints with variable areas of a dhesion using an impact-based technique, and the relationship of adher ed area to measured failure energy was obtained for the three systems. The failure interface was examined by scanning electron microscopy. I t was found that the poly(2-allyl)phenylene oxide-treated system gave the highest failure energies, followed by the untreated system. The el ectropolymer film system with pre-crosslinked allyl functionality prod uced the lowest failure energies. These results were related to the na ture of the chemical interactions present at the interfaces, in accord ance with the theories of adhesion proposed by Kinloch. (C) 1996 John Wiley & Sons, Inc.