Adhesive properties onto galvanized steel plates of grafted poly(vinylidene fluoride) powders with phosphonated acrylates

Abstract

Hydrophilic fluoropolymers were obtained by grafting phosphonated monomers onto activated poly(vinylidene fluoride) (PVDF). By using an ozonization technique, dialkylperoxide and hydroperoxide groups were formed onto PVDF which may be decomposed thermally in a subsequent step to initiate graft copolymerization. By using an iodometric titration technique, the effect of ozone oxidation time and temperature on the concentration of peroxides was studied. However, degradation was observed by viscosimetry and FTIR for the hardest ozonization conditions. An effect of the grafting conditions (monomer concentration and monomer end groups) on the degree of grafting was determined and diester-acrylated phosphonate is grafted at a higher rate than are the homologous acid derivatives. Adhesion of the graft copolymers applied to galvanized steel substrates was studied. The experiments clearly show stronger adhesive properties of PVDF coatings containing phosphonic acid functions than those of the ones containing carboxylic acid functions. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 611–620, 1999