New Aliphatic Poly(ester-carbonates) Based on 5-methyl-5-allyloxycarbonyl-1,3-dioxan-2-one

The synthesis, characterization, and ring-opening polymerization of a new cyclic carbonate monomer containing an allyl ester moiety, 5-methyl-5-allyloxycarbonyl-1,3-dioxan-2-one (MAC), was performed for the first time. MAC was synthesized in five steps in good yield beginning from the starting material, 2,2-bis(hydroxymethyl)propionic acid. Subsequent polymerization and copolymerizations of the new cyclic carbonate with rac-lactide (rac-LA) and epsilon-caprolactone (CL) were attempted. Rac-LA copolymerized well with MC, but CL copolymerizations produced insoluble products. Oligomeric macroinitiators of MAC and rac-LA were synthesized from stannous ethoxide, and both macroinitiators were used for the controlled ring-opening polymerization of rac-LA. The polymerization kinetics were examined by monitoring the disappearance of the characteristic C-O ring stretch of the monomer at 1240 cm(-1) with real-time in situ Fourier transform infrared spectroscopy. Postpolymerization oxidation reactions were conducted to epoxidize the unsaturated bonds of the MAC-functionalized polymers. Epoxide-containing polymers may allow further organic transformations with various nucleophiles, such as amines, alcohols, and carboxylic acids. NMR was used for microstructure identification of the polymers, and size exclusion chromatography and differential scanning calorimetry were used to characterize the new functionalized poly(ester-carbonates). (C) 2003 Wiley Periodicals, Inc