POLYMERIZATION OF METHYL-METHACRYLATE WITH COBALT ACETYLACETONATE-DIETHYL ZINC CATALYST SYSTEM

Polymerization of methyl methacrylate was studied with a cobalt acetyl acetonate -diethyl zinc catalyst initiator system in benzene medium at 40 degrees C. When the stoichiometric ratio of Zn/Co is 2, the activi ty for polymerization is found to be maximum. The structure of the obt ained polymethyl methacrylate is compared with that obtained using a f ree-radical initiator such as benzoyl peroxide. The structure of polym er and the (M) over bar(w)/(M) over bar(n) values indicate that cobalt acetylacetonate-zinc diethyl system has pronounced free-radical chara cteristics. A suitable mechanism is proposed from the kinetic studies. (C) 1995 John Wiley and Sons, Inc.