Trimethoxyvinylsilane (TMVS) was quantitatively polymerized at 130 degrees C in bulk, using dicumyl peroxide (DCPO) as initiator. The polymerization of TMVS with DCPO was kinetically studied in dioxane by Fourier transform near-infrared spectroscopy. The overall activation energy of the bulk polymerization was estimated to be 112 kJ/mol. The initial polymerization rate (R-p) was expressed by R-p = k[DCPO](0.6)[TMVS](1.0) at 120 degrees C, being closely similar to that of the conventional radical polymerization involving bimolecular termination. The polymerization system involved electron spin resonance (ESR) spectroscopically observable polymer radicals under the actual polymerization conditions. ESR-determined apparent rate constants of propagation and termination were 13 L/mol s and 3.1 X 10(4) L/mol s at 120 degrees C, respectively. The molecular weight of the resulting poly(TMVS)s was low (M-n = 2.0-4.4 x 10(3)), because of the high chain transfer constant (C-mtr = 4.2 x 10(-2) at 120 degrees C) to the monomer. The bulk copolymerization of TMVS (M-1) and vinyl acetate (M-2) at 120 degrees C gave the following copolymerization parameters: r(1) = 1.4, r(2) = 0.24, Q(1) = 0.084, and e(1) = +0.80. (c) 2005 Wiley Periodicals, Inc.