Jean-Pierre Parisi

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

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.

Homopolymerization and copolymerization of salt formed from a new diethyl styrenic phosphonate monomer

Abstract The synthesis of a new styrenic monomer bearing a diester phosphonic group is presented. The dealkylation was performed by the action of trimethylsilane followed by a methanolic hydrolysis. Such a diacid was not stable and led to polyphosphonic anhydride. In order to circumvent this drawback, the diacid was chemically changed to the corresponding monoacid-monosalt. Homopolymers of this salt and copolymers with methyl methacrylate (MMA) were obtained, since a departure of amine was observed during the polymerization and when the polymers were heated. These polymers exhibit high values of Tg (close to 200 °C).

New diethyl phosphonoalkyl acrylates and their reactivity in copolymerization

SummaryTwo new diester phosphonoalkyl acrylate monomers were synthesized and their reactivity in copolymerization was determined. The selective hydrolysis of diester homologues was performed. The polymerization of the diacid homologue produced a non soluble gel. On the contrary, the polymer of the monoacide/mono salt homologue was soluble in methanol.

Electron-beam curable structural adhesives. Part 1: Study of acrylic resins for structural adhesive applications

Abstract Different commercial acrylic resins, which can be cured via electron-beam radiation, have been selected for structural adhesive applications. This paper presents and discusses their most important bulk characteristics after radiation curing and their evaluation as adhesives by measurement of the single lap shear strength on stainless steel. The relationships between structure and adhesion on the one hand, and between mechanical properties and adhesion on the other, are discussed.

Functionalization of a multiepoxy resin by methacrylic compounds and study of its thermal properties

SummaryMethacrylation of triglycidyl triphenyl methane (via methacrylic acid) has been done using three catalysts: dimethyl dodecyl amine (DMDA), tetrabutyl ammonium bromide (TBAB) and chromium (III) diisopropyl salicylate (Cr Dips). The reaction has been followed by epoxy colorimetric titration, CPG and 1H NMR.This study has shown the superiority of chromium catalysis because of its rapidity and ease of process.Then, these cured products (TACTIX and methacrylated TACTIX) show homogeneous Tg values which are higher than 200°C.

Easy use of Lewis and Mayo's rule to determine monomer conversion-rates in cotelomerization

SummaryThe Lewis and Mayos rule, used so far for the determination of r1 and r2, is presently applied for the simultaneous determination of partial monomers conversions α1 and α2; whereas the integration of the Skeists rule gave global conversion α only. An experimental verification is performed for the cotelomerization of MMA and maleic anhydride with dodecyl mercaptan as telogen, and it gives a very good correlation.