Free‐radical polymerization of methyl methacrylate at very high conversions, 2. Study of the kinetics of initiation by benzoyl peroxide

Abstract

The initiation kinetics of the free-radical polymerization of methyl methacrylate at very high monomer conversions was investigated at 80, 100, and 120°C. Using a HPLC (high performance liquid chromatography) analytical technique with UV detection, the consumption of both monomer and initiator as well as the formation of reaction products of the latter could be followed. It was found that (besides very small amounts of biphenyl and benzoic acid) phenyl benzoate is the main decomposition product. The experimental results were analyzed quantitatively with the help of a reaction scheme which takes into account the most important pathways of that complex chemical reaction system. Thus, it was found that, due to the very strong cage effect in the present polymerization system, the experimentally accessible (apparent) first order rate constant of initiator decomposition is substantially lower than that for the primary cleavage of a benzoyl peroxide molecule. Efficiencies of chain initiation were calculated to be in the range of 0,l to 0,2 in the (nearly) glassy polymer matrix.

An experimental and theoretical study of butyl methacrylatein situradical polymerization kinetics in the presence of graphene oxide nanoadditive

“…Following Stickler and Dumont the initial initiator efficiency ( f 0 ) was set equal to unity. By using the low conversion versus time data of neat BMA homopolymerization at the temperature range 60 to 80 °C, the application of standard methods of nonlinear regression analysis reveals values for k t0 equal to 1.2 × 10 9 e −1770/T dm mol −1 s −1 .…”

“…The fitted data includes conversion data at three different temperatures and the number average molecular weight at the end of polymerization time. Following once again Stickler and Dumont the initial initiator efficiency ( f 0 ) was set equal to unity and the k t0 value previously estimated was used. Standard methods of nonlinear regression analysis were used .…”

Toward the development of a mathematical model for the bulk in situ radical polymerization of methyl methacrylate in the presence of nano‐additives

“…For the propagation rate constant, the reported values of Beuermann et al were used. Data for the initiator kinetic rate constant are given in standard literature references …”

Statistical Glycopolymers Based on 2‐Hydroxyethyl Methacrylate: Copolymerization, Thermal Properties, and Lectin Interaction Studies

“…The synthesis of 2‐{[( D ‐glucosamin‐2‐ N ‐yl)carbonyl]oxy}ethyl methacrylate, HEMAGl, is described elsewhere 26. Methyl acrylate, MA (Merck), was purified by a conventional method 32. 2,2′‐Azobisisobutyronitrile, AIBN (Fluka), was purified by successive crystallizations from methanol.…”