RADICALLY INITIATED POLYMERIZATION OF A METHACRYLOYLAMIDO-TERMINATED SACCHARIDE .1. MONOMER SYNTHESIS, HOMOPOLYMERIZATION AND CHARACTERIZATIONS

A methacrylamido-terminated saccharide, 6-deoxy-6-methacryloylamido-D- glucopyranose (MAG), was synthesized using a new and easy pathway. Kin etics of the radically initiated solution homopolymerization of this m onomer was investigated at 50 degrees C using 4,4'-azobis(4-cyanopenta noic acid); the obtained k(p)/k(t)(1/2) value around 1.0 mol(-1/2). L( 1/2). s(-1/2) is indicative of the strong ability of MAG to polymerize (k(p) and k(t) being the rate constants of propagation and terminatio n, respectively). The chemical structure of the homopolymer, as analyz ed by C-13 NMR spectroscopy shows a tacticity which is in favor of a s yndiotactic configuration resulting from the bulkiness of the side gro up. The dimensional characteristics of the polymers were studied by li ght scattering as an on-line detection in size exclusion chromatograph y (SEC). As expected from the k(p)/k(t)(1/2) value, high weight-averag e molecular weights were obtained. The small average radii of gyration were found to reflect a relatively compact structure in water due to inter- and intramolecular interactions; viscosity studies in various s olvents as well as values of the second virial coefficient corroborate such a behavior which reflects that water is a poor solvent for poly( MAG).