Synthesis of Polyphosphorinanes. 1. Homopolymerization and Telomerization of Allyl Ether Phosphite

Cyclic allyl phosphonated monomers were synthesized by transesterification reaction between a glycol bearing a double bond and a hydrogenophosphonate and were fully characterized by NMR and IR spectroscopy. Radical homopolymerization of these monomers was carried out at 70 °C in the presence of α,α′-azoisobutyronitrile (AIBN) as initiator and acetonitrile as solvent. The thus-obtained polymers showed two SEC distributions, one composed of oligomers (with M_n ≈ 800 g/mol) and one composed of high-molecular-weight polymers (with M_n ≈ 100 000 g/mol). The latter were hyperbranched polymers suffering from solubility limitations for future industrial applications. Therefore, telomerization of one phosphonated monomer using dimethyl hydrogenophosphonate (HP(O)(OMe)₂) as a chain transfer agent (CTA) limited the hyperbranching through two concomitant mechanisms of polymerization, which are discussed. For R₀ = 2 (R₀ represents initial [CTA]₀/[monomer]₀ molar ratio), the results showed a limited chain length, whereas monoadduct formation occurred for a R₀ value of 10.