Butyl acrylate (BA) - styrene (ST) copolymerization was carried out in bulk without any free-radical initiator at 110, 150 and 170°C. The Kelen-Tudos (K-T) transformation of comonomers-copolymer composition data shows that the copolymerization can be sufficiently described by a terminal copolymerization model. Reactivity ratios for BA (r,) and ST (r2) were estimated by the K-T method as well as by the error-in-variables method. Together with previous reports on BA-ST copolymerization at 50 and 60°C, these values of rl and r 2 served to find the Arrhenius relationships: In r 1 = 1.3510- 1034.1/T, and In r2 =0.05919-131.6/T, where T is absolute temperature. Thus, although r, can be strongly affected by temperature, r 2 is practically temperature insensitive. This can be explained by the activation energy differences between homo- and cross-propagations (8.6 and 1.1 kJ mol- 1, respectively). Effect of conversion on copolymer and comonomers composition is also discussed.
Посилання на статтю:
Influence of temperature on butyl acrylatestyrene copolymerization parameters / Leopold K. Kostanski and Archie E. Hamielec // Polymer. – 1992. – Vol 33. – P. 3706-3710.