Microemulsion and Conventional Emulsion Copolymerizations of Styrene with n-Butyl Methacrylate, and Characterization of the Copolymers

Abstract

Microemulsion (ME) and conventional emulsion (CE) copolymerization of styrene (STY) with n-butyl methacrylate (BMA) were carried out at 70^oC under inert atmosphere with sodiumlauryl sulphate (SLS) as surfactant, n-hexanol (HA) as cosurfactant and potassium persulphate (KPS) as the free radical initiator. Five monomer mixtures in the initial reaction mixtures were used and the reactions were arrested at lower conversions. The copolymers thus obtained were characterized by FTIR, NMR, TG/DTA, GC and GPC. The monomer composition of the copolymers were evaluated from the ¹HNMR spectral data. The reactivity

ratios for the ME and CE copolymerization of styrene (STY) (r_STY) with n-butyl methacrylate (BMA) (r_BMA) as determined by Fineman-Ross (F-R), Kelen-Tudos (K-T) and Mayo-Lewis (M-L) methods were 0.74±0.02 and 0.64±0.02, and 0.58±0.02 and 0.39 ±0.02, respectively.