COPOLYMERIZATION PROPAGATION KINETICS OF STYRENE WITH ALKYL ACRYLATES

Propagation rate constants have been determined at two temperatures (298 K and 323 K) for the copolymerizations of styrene (STY) with methyl acrylate (MA) and STY with n-butyl acrylate (BA) over a range of monomer feed compositions. A pulsed UV laser was used as an initiation source and gel permeation chromatography (GPC) was utilized to analyse the products. None of the copolymerizations conformed to the Mayo-Lewis model, with respect to their propagation rate constants. The results were interpreted on the basis of a penultimate effect on the propagation reaction. In addition, Mark-Houwink constants were determined for poly(MA) and poly(BA) in tetrahydrofuran (THF) at 298 K. These constants are given as [K(dm3 kg-1),a]:7.88 x 10(-3), 0.885 and 8.57 x 10(3), 0.865 for poly(MA) and poly(BA) respectively.