Radical polymerization behavior of dimethyl vinylphosphonate: Homopolymerization and copolymerization with trimethoxyvinylsilane

Abstract

AbstractDialkyl vinylphosphonates such as dimethyl vinylphosphonate (DMVP) and diethyl vinylphosphonate were quantitatively polymerized with dicumyl peroxide (DCPO) at 130°C in bulk. The polymerization of DMVP with DCPO was kinetically studied in bulk by fourier transform near‐infrared spectroscopy (FTNIR) and electron spin resonance (ESR) spectroscopy. The initial polymerization rate (Rp) was given by Rp = k[DCPO]0.5[DMVP]1.0 at 110°C, being the same as that of the conventional radical polymerization involving bimolecular termination. The overall activation energy of the polymerization was estimated to be 26.2 kcal/mol. The polymerization system involved ESR‐observable propagating polymer radicals under the practical polymerization conditions. ESR‐determined rate constants of propagation (kp) and termination (kt) were kp = 19 L/mol s and kt = 5.8 × 103 L/mol s at 110°C, respectively. The molecular weight of the resultant poly(DMVP)s was low (Mn = 3.4 − 3.5 × 103), because of the high chain transfer constant (Cm = 3.9 × 10−2 at 110°C) to the monomer. DMVP (M1) showed a considerably high reactivity in the radical copolymerization with trimethoxyvinylsilane (TMVS) (M2) at 110°C in bulk, giving an inorganic component‐containing functional copolymer with potential flame‐retardant properties; r1 = 1.6 and r2 = 0. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008