REACTIVITY RATIOS IN GROUP-TRANSFER COPOLYMERIZATION OF METHYL METHACRYLATE ETHYL METHACRYLATE AND METHACRYLONITRILE/METHYL METHACRYLATE SYSTEMS OBTAINED BY SEMI-INTEGRAL AND INTEGRAL METHODS/

The monomer reactivity ratios for the methyl methacrylate/ethyl methac rylate (MMA/EMA) and methacrylonitrile/methyl methacrylate (MAN/MMA) s ystems are calculated by linearized semi-integral and nonlinear fully integral methods. For the MMA/EMA system, r(MMA) values obtained by va rious methods are between 1.24 and 1.25 and r(EMA) values between 0.30 and 0.34. For MAN/MMA system, r(MAN) values are between 3.2 and 3.8 a cid for r(MMA) an upper bound can be determined, i.e., r(MMA)<0.05. Th e results show that previous values obtained by the linearized method (the initial Kelen-Tudos method) overestimate the reactivity of the le ss active monomer.