• copolymer;
  • glass transition temperature;
  • structure-property relations;
  • composition;
  • substituent effect


In this article, bulk copolymerization of methyl methacrylate (MMA) with ethyl methacrylate (EMA) and n-butyl methacrylate (n-BMA) was carried out at 60°C. The monomer reactivity ratios obtained by nonlinear fitting with Mayo-Lewis equation were as follows: rMMA = 0.93 ± 0.03, rEMA = 0.96 ± 0.03 for the MMA/EMA, and rMMA = 0.99 ± 0.05, rn-BMA = 1.11 ± 0.06 for the MMA/n-BMA series. A new equation proposed in view of bond rotation flexibility (Liu et al., J Phys Chem B 2008, 112, 93), which contains mole fractions of triads and Tg's of corresponding periodic copolymers, was applied to describe the relation of Tg's of MMA-EMA, MMA-n-BMA copolymers with their compositions and sequence distribution. Excellent fitting results were obtained and Tg values of the assumed periodic copolymers were predicted by fitting the random copolymers. The influence of the substituent volume as well as substituent density on the Tg of poly(methyl methacrylate) (PMMA) was also tentatively predicted. © 2009 Wiley Periodicals, Inc. J Appl Polym, 2009