Radical polymerization of new activated cyclic esters

Abstract

Various substituted lactones, 4-methylene-1,3-dioxolan-2-one, 4,4dimethyl-5-methylene-1, 3-dioxolan-2-one, 4-methyl-5-methylene-4-phenyl-1, 3dioxolan-2-one, 4-phenyl-5-vinyl-1,3-dioxolan-2-one, 3-phenyl-4-vinyl-2-oxetanone and 3-methyl-3-phenyl-4-vinyl-2-oxetanone, were prepared and their polymerization behavior were investigated. Polymerization of the above monomers were carried out with common radical initiators such as 2,2``-azobisisobutyro-nitrile, dibenzoyl peroxide, di-t-butylperoxide, dicumyl peroxide or t-butylhydroperoxide. 4-Methylene-1,3-dioxolan-2-one polymerized in neat or in solution to give solid polymer. The conversions were higher in bulk polymerization (78-91\% yield) than in solution polymerization (36-62\% yield) in that chlorobenzene was used as solvent. The resulting polymers were soluble in dimenthylsulfoxide but insoluble in common organic solvents such as chloroform and acetone. $1_H$-NMR and IR spectral data confirmed that the polymerization proceeded via vinyl type cleanly, thus obtained polymer contained carbonate ring as a pendent group. Hydrolysis of the carbonate ester group of the polymer obtained from 4-methylene-1,3-dioxolan-2-one was carried out with sodium methoxide. The hydrolyzed polymer was soluble in cold water and spectral data indicated that pendent carbonate ring was hydrolyzed leaving hydroxy and hydroxy methyl groups behind. In case of 4, 4-dimethyl-5-methylene-1,3-dioxolan-2-one and 4-methyl-5-methylene-4-phenyl1, 3-dioxolan-2-one, which have alkyl or aryl substituents at 5-position of 4-methylene-1,3-dioxolan-2-one, polymerization did not proceed and the monomers were recovered. However, 4, 4-dimethyl-5-methylene-1, 3-dioxolan-2one, which has less bulky substituents, could be copolymerized in high yield (95\%) when vinyl acetate was used as a comonomer. In this copolymerization, 4, 4-dimethyl-5-methylene-1, 3-dioxolan-2-one was also incorporated into the copolymer via addition type reaction. 4-Phenyl-5-vinyl-1, 3-d...