ESTER DERIVATIVES OF ALPHA-HYDROXYMETHYLACRYLATES - ITACONATE ISOMERSGIVING HIGH-MOLECULAR-WEIGHT POLYMERS

New ester derivatives of ethyl alpha-hydroxymethylacrylate were synthe sized using acid chlorides (traditional solution reactions), sodium sa lts of acids (with phase transfer catalysis), and trifluoroacetic anhy dride (trifluoroacetate). The interfacial process gave high yields of clean products under very mild conditions. Derivatives obtained includ e the formate, acetate, hexanoate, stearate, benzoate, trifluoroacetat e, and adamantanoate. Bulk polymerizations with 2,2'-azobis(isobutyron itrile) gave high molecular weight polymers with intrinsic viscosities of over 2 dL/g and molecular weights of several million [based on siz e-exclusion chromatography (SEC) comparison to polystyrene standards]. These high molecular weights were the result of autoacceleration in t he bulk as shown by monitoring molecular weight with respect to conver sion. Solution polymerization in benzene gave more typical polymer, e. g., the acetate derivative showed an SEC molecular weight of 52,000. G lass 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 tr ansitions were observed for the trifluoroacetate, benzoate, and adaman tanoate 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-stat e C-13-NMR analysis gave spectra with functional group peaks and chemi cal shift values expected based on composition. The stearate monomer a nd polymer gave solid-state C-13 chemical shifts of 34 and 33 ppm, res pectively, for the central CH2 units consistent with monoclinic and or thorhombic crystal packing. (C) 1994 John Wiley and Sons, Inc.