SYNTHESIS AND CHARACTERIZATION OF ANIONIC GRAFT-COPOLYMERS CONTAININGPOLY(ETHYLENE OXIDE) GRAFTS

Anionic graft copolymers were synthesized through grafting of poly(eth ylene glycol) monomethyl ether (MPEG) onto terpolymers containing succ icinic anhydride groups. The backbone polymers were prepared through r adical terpolymerization of maleic anhydride, styrene, and one of the following monomers: methyl methacrylate, ethylhexyl methacrylate, and diethyl fumarate. MPEG of different molecular weights were grafted ont o the backbone through reactions with the cyclic anhydride groups. In this reaction one carboxylic acid group is formed together with each e ster bond. The molecular weights of MPEG were found to influence the r ate of the grafting reaction and the final degree of conversion. The g raft copolymers were characterized by IR, GPC, and IH-NMR. Thermal pro perties were examined by DSC. Graft copolymers containing 50% w/w of M PEG 2000 grafts were found to be almost completely amorphous, presumab ly because of crosslinking, and hydrogen bonding between carboxylic ac id groups in the backbone and the ether oxygens in MPEG grafts. (C) 19 95 John Wiley and Sons, Inc.