ESTER DERIVATIVES OF ALPHA-HYDROXYMETHYLACRYLATES - ITACONATE ISOMERS GIVING HIGH-MOLECULAR-WEIGHT POLYMERS

New ester derivatives of ethyl alpha-hydroxymethylacrylate were synthesized using acid chlorides (traditional solution reactions), sodium salts of acids (with phase transfer catalysis), and trifluoroacetic anhydride (trifluoroacetate). The interfacial process gave high yields of clean products under very mild conditions. Derivatives obtained include the formate, acetate, hexanoate, stearate, benzoate, trifluoroacetate, and adamantanoate. Bulk polymerizations with 2,2'-azobis(isobutyronitrile) gave high molecular weight polymers with intrinsic viscosities of over 2 dL/g and molecular weights of several million [based on size-exclusion chromatography (SEC) comparison to polystyrene standards]. These high molecular weights were the result of autoacceleration in the bulk as shown by monitoring molecular weight with respect to conversion. Solution polymerization in benzene gave more typical polymer, e.g., the acetate derivative showed an SEC molecular weight of 52,000. Glass transition temperatures for the n-alkyl esters decreased from the formate (77 degrees C) to the hexanoate (15 degrees C); the stearate showed a side-chain melting point of 40 degrees C but no T-g. Glass transitions were observed for the trifluoroacetate, benzoate, and adamantanoate polymers at 69, 130, and 214 degrees C, respectively. Solution C-13-NMR showed evidence of tacticity information for the formate and acetate derivatives with apparent preference for syndiotactic polymer formation similar to that of methyl methacrylate. FTIR and solid-state C-13-NMR analysis gave spectra with functional group peaks and chemical shift values expected based on composition. The stearate monomer and polymer gave solid-state C-13 chemical shifts of 34 and 33 ppm, respectively, for the central CH2 units consistent with monoclinic and orthorhombic crystal packing. (C) 1994 John Wiley and Sons, Inc.