Use of Polyacrylic Acid Electrolytes Diffused in Zinc Phosphate Conversion Coatings for the Corrosion Protection of Steel

摘要

Polyacrylic acid (p(AA)), electrolyte macromolecules diffused into crystalline zinc phosphate (Zn.Ph) conversion coatings that are precipitated onto cold-rolled steel by dissolution-recrystallization processes, enhance the corrosion protection of steel. One of the specific subserviences was that, when the NaOH-dissolution of Zn.Ph is considered, the Zn-OOC electrostatic bonds at p(AA)-Zn.Ph interfaces are transformed into Na+-OOC ionic bonds which associate with the salt complexed macromolecules. Another is the intermolecular chemical reactions between p(AA) and polymeric topcoats. These contributions relate directly to a lower cathodic delamination rate. Keywords: Coatings; Corrosion inhibition; Reprints. (kt)