Vinylphosphonate vinyl monomers

The free radical polymerizations of cyclic ketene acetals have recently evoked a lot of interest (10-13). TTie oly(e-caprolactone) (PCL) can be synthesized by free radical ring opening polymerization (10). The copolymerization of its monomer, 2-methylene-l,3-dioxepane (MDO), with some vinyl monomers resulted in an aliphatic ester backbone, as well as the pendant functional groups from the vinyl monomers (10). By free radical polymerization of MDO and the vinyl monomers vinylphosphonic acid (VPA), dimethylvinylphosphonate (VPE) and acrylic acid (AA), we synthesized a series of biodegradable copolymers including PCL... 

Organophosphorus Monomers. Many vinyl monomers containing phosphoms have been described in the Hterature (76), but few have gone beyond the laboratory. Bis(2-chloroethyl) vinylphosphonate [115-98-0] C H Cl O P, is a commercially available monomer (Akzo s Fyrol Bis-Beta) made from bis(2-chloroethyl) 2-chloroethylphosphonate. 

Yakubovich, A.Y., Soborovskii, L.Z., Muler, L.L, and Faemark, V.S., Synthesis of vinyl monomers. Part 1. a-Substituted derivatives of vinylphosphonic acid, Zh. Obshch. Khim., 28, 317, 1958 Chem. Abstr, 52, 13613c, 1958. 

Phosphonates. The principal synthetic routes include addition and condensation methods. Although a large number of vinyl and diene phosphonate monomers have been described in the literature (2,5,7,62), only bis(2-chloroethyl) vinylphosphonate (Akzo-Nobel s Fyrol Bis-Beta monomer), vinylphosphonic acid (Clariant), and dimethyl vinylphosphonate (Clariant) have been offered commercially. The diethyl vinylphosphonate is available in laboratory quantities. 

Aldehydes have been the primary source of eleetrophiles since the initial MBH reaetion was explored. On the basis of both eleetronic and steric considerations, they are much more active than simple ketones. Formaldehyde ean be employed as an aqueous solution (formahn), the polymer (paraformaldehyde), as a solution of the monomer in an organie solvent or as a hemiacetal (Scheme 1.43). Similar results were obtained in eouplings of aldehydes with acrylonitrile, methyl vinyl ketone and phenyl vinyl sulfone. However, aqueous formaldehyde can not react with diethyl vinylphosphonate. ... 

Bis(2-chloroethyl)vinylphosphonate, CH CH P(0)(0CH2CH2C1)2 can be used to form emulsion copolymers with vinyl halides, or it may be used on its own and mechanically incorporated into textile fibres. Compound (12.212a) when dispersed in rayon is an effective retardant additive [44], while (12.212b), when copolymerised with a suitable monomer, will act as an intumescent flame retardant. 

Vinylphosphonates are slow to homopolsunerize. They copolymerize with most common monomers but particularly well with vinyl acetate (63), vinyl chloride, and acrylonitrile (64). The copolymerization Q and e values for bis(2-chloroethyl) vinylphosphonate are 0.23 and 1.73, respectively (65), reflecting an electron-poor double bond and low resonance stabilization of the free radical. They are also prone to chain transfer. Representative copolymers have been studied and evaluated for their expected flame-retardant action (66) but cost considerations have generally not encouraged commercial use of vinylphosphonate esters for this purpose. 

Other examples of specialty anionic monomers shown in Figure 33 include salts of vinylphosphonates lOA, vinylphenolates 1 lA, vinyl benzoate 12A, maleic acid 13A, 3-vinyloxypropane sulfonates 14A, and A -vinylsuccinimidic acid 15A. 

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