Claire Negrell-Guirao

Recent progress on phosphonate vinyl monomers and polymers therefore obtained by radical (co)polymerization

This review paper gathers almost one hundred recent publications devoted to the synthesis and the free radical (co)polymerization of phosphonate vinyl monomers. Different synthetic approaches are discussed to introduce the phosphonate moieties into vinyl monomers, focusing especially on recent advances. Allyl-type, vinyl-type, styrenic-type and (meth)acrylic-type monomers bearing phosphonate groups (i.e. either mono or bisphosphonate) are considered with a special care about their reactivity in free radical (co)polymerization. It is shown that depending on the position of the phosphonate moieties the reactivity of the vinyl monomers is thus modified. For instance, free radical polymerization of vinyl phosphonate monomers is mainly dominated by transfer reactions, whereas the propagation rate of para-vinylbenzyl phosphonate monomers is enhanced by the phosphonate group. According to the structure of the phosphonate-bearing (co)polymers, the resulting properties are also investigated.

Synthesis of biobased phosphate flame retardants

Abstract An approach to prepare some biobased flame retardant (FR) compounds is presented. The adopted strategy consists in functionalizing an aromatic biobased phenolic compound, the phloroglucinol, with different phosphate groups in order to promote a charring effect. Different chlorophosphates were grafted onto phloroglucinol hydroxy groups and the functionalization of the hydroxy groups was quantitative. The synthesized biobased FR were incorporated into an epoxy matrix as additive to estimate their flame retardant properties. The influence of different parameters was studied such as the phosphorus content of the thermoset or the nature of the R group of the used phosphate P-O-R. MEB/EDX observations proved the influence of this R group on the compatibility between the FR and the matrix and its importance to obtain homogeneous thermoset. Thermogravimetric analyses of the phosphorus-containing thermosets showed a small decrease in thermal stability accompanied by a char yield almost tripled for a 3 %wP-containing thermoset compared to that of the thermoset without any FR. Pyrolysis combustion flow calorimetry was also used to evaluate the flammability of the modified epoxy thermoset. A significant decrease in peak of heat release rate and total heat released was observed compared to thermoset without FR. These results demonstrate the good flame retardant properties of these biobased phosphates in an epoxy matrix. In addition these results show the potential of the biobased phenolic compounds as raw material for flame retardants syntheses.

CHAPTER 10:Complexation with Metals: Anticorrosion Phosphorus-Containing Polymer Coatings

This chapter reviews the recent trends concerning the development of organic coatings containing phosphonic acid moieties, able to act as anticorrosion coatings. The performances of coatings made from blend polymers, comprising a methacrylate polymer with phosphonic acid moieties associated with a halogenated polymer, were first analyzed. A second strategy consists in making coatings by UV polymerization of (meth)acrylates containing phosphonic acid moieties. The adhesion of phosphonic acid moieties towards metallic surfaces is here described, thus allowing polymeric coatings with strong anticorrosive properties.

An environmental application of functionalized chitosan: enhancement of the separation of the solid and liquid fractions of digestate from anaerobic digestion

Abstract A high molecular weight chitosan was chemically modified to quantitatively incorporate quaternary ammonium groups. Its efficiency was evaluated in the liquid-solid separation for various liquors, and compared with the one of a polyelectrolyte usually used for this utilization. The performance of the liquid-solid separation was estimated through the determination of two parameters measured after the screening- settling of the mixture liquor/flocculating agent: the separation efficiency (EV) and the TS removal efficiency (ETS). Apart for liquor 6, TS removal was always better after an addition of functionalized chitosan. Furthermore, whatever the type of liquor, the distribution was modified by an increased presence of high-size particles when functionalized chitosan was added. Moreover, chitosan addition tended to homogenize the size of the particles, which could facilitate the choice of the liquid-solid separation process. This homogenization was particularly observed for the liquor initially highly dispersed in size, i.e. liquors 1, 4, 6 and 8.

CHAPTER 3:Phosphorus-Containing Vinyl or Allyl Monomers

This chapter reviews the synthetic strategies that can be used for phosphonate-containing vinyl monomers, ranging from allyl-type to vinyl- and vinyl ether-type monomers. Their radical copolymerizations with electron-accepting monomers are thoroughly described and lead to materials that can be used for different applications, such as anticorrosive coatings. For instance, the free radical polymerization of 5-(allyloxymethyl)-1,3,2-dioxaphosphorinane 2-oxides with maleic anhydride affords very interesting flame retardant compounds.