EFFECT OF GRAFT CHAIN-LENGTH OF THE STABILIZER ON DISPERSION POLYMERIZATION OF METHYL-METHACRYLATE IN PETROL

To carry out dispersion polymerization of methyl methacrylate (MMA) in petrol, we have used a poly (MMA) grafted-poly(12-hydroxystearic acid ) copolymer as the stabilizer. This special copolymer was prepared as a solution in a mixture of ethyl acetate and butyl acetate solvents. W e investigated the effect of graft chain length of the stabilizer on t he dispersion polymerization in petrol. We synthesized the stabilizer copolymer with n = 1-4 and determined the rate and the molecular weigh t of the PMMA formed. There is no dispersion polymerization for n = 1. However, for any other n, for a given stabilizer concentration, as th e chain length of the graft is increased, the molecular weight as well as the rate of PMMA formation increases. As opposed to this for a giv en graft length as the concentration of the stabilizer increases, the molecular weight of PMMA first rises, but for a larger concentration, it begins to fall after undergoing a maximum. In this work, we modeled the heterogeneity of the reaction mass and proposed a mathematical mo del for dispersion polymerization of MMA in petrol. The computer resul ts are found to conform to the experimentally observed molecular weigh t of the PMMA. (C) 1993 John Wiley & Sons, Inc.