STUDIES ON THE REACTIVITY RATIOS OF STYRE NE AND BUTYL ACRYLATE

In this study, copolymerizations of styrene(St, M(1)) and butyl acryla te (BA, M(2)) were carried out at 60,80,100,120 and 140 degrees C at t wo sensitive feed compositions. Compositions of copolymers were analyz ed by H-1 NMR. Reactivity ratios were calculated by Error-in-Variable method to be r(1) = 0.688, r(2) = 0.157; r(1) = 0.378, r(2) = 0.174; r (1) = 0.772, r(2) 0.201; r(1) = 0.810, r(2) = 0.216 and r(1) = 0.851, r(2) = 0.241 at various polymerization temperatures above. The differe nces of activation energies between homo-polymerization and copolymeri zation were obtained to be E(11) - E(12) = 2.97 kJ/mol, E(22) - E(21) = 6.13 kJ/mol. The chain length distribution at 60 degrees C and Q, e values of BA at 60 degrees C were also calculated.