Polymerization of cyclic esters of phosphoric acid. VI. Poly(alkyl ethylene phosphates). Polymerization of 2-alkoxy-2-oxo-1,3,2-dioxaphospholans and structure of polymers
Jan Libiszowski,Krzysztof Ka?u?ynski,Stanis?aw Penczek
Abstract:
Five-membered cyclic esters of phosphoric acid of the general formula: ? CH2CH(R)OP(O)-(OR′)O? polymerize readily to solid, soluble polymers of high molecular weight without any rearrangement known for various tri- and pentavalent organophosphorus monomers. 1H-, 13C-, and 31P-NMR spectra of polymers confirmed their linear structure: where R is H, with R′ = CH3, C2H5, n-C3H7, i-C3H7; n-C4H9, CCl3CH2, or C6H5, or R is CH2Cl and R′ is C2H5. The use of n-C4H9Li, (C5H5)2Mg, or (i-C4H9)3Al as initiators leads to polymers with Mn = 104–105.