No abstract

SYNOPSISThe action of methacrylic acid onto tetraglycidyl methylene dianiline, tetraglycidyl sulfone dianiline, triglycidyl triphenylmethane ( TACTIX) , and epoxy novolac resins was performed using different catalysts. In each case, a comparative study of these catalysts was investigated depending upon the polarity of the solvent and of the temperature. Chromium complexes are better in low polar solvents. The reactions were monitored by 'H-NMR, by epoxide titration, and by size exclusion chromatography (SEC) , and the reactivity of these resins could be compared. Finally, the study of these materials obtained after radical and photochemical cross-linking, especially by dynamic mechanical analysis (DMA) , shows that these materials exhibit high T l s (2OOOC for methacrylated TACTIX) compared to those of the corresponding multiepoxides cured by diamines. 0 1993 John Wiley & Sons, Inc.

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.

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.