Copolymerization of methylmethacrylate with styrene using triphenylbismuthoniumylide as radical initiator

Bismuthoniumylide-initiated radical copolymerization of methylmethacrylate with styrene at 60 +/- 0.2 degreesC using dioxane as an inert solvent, foll ows ideal kinetics (R-p proportional to [ylide](0.5) [MMA](1.0) [sty](1.0)) , and yields alternating copolymer as evident from NMR spectroscopy. The va lues of reactivity ratios r(1) and r(2), calculated from Finemann-Ross meth od are 0.48 and 0.45, respectively. The system follows ternary molecular co mplex mechanism. The radical mode of polymerization has keen confirmed by E SR spectroscopy and the effect of hydroquinone. The value of activation ene rgy and k(p)(2)/k(t) are 65.0 KJ mol(-1) and 2.5 x 10(-5) mole(-1) s(-1), r espectively. (C) 2001 John Wiley & Sons, Inc.