Polymerization of methyl methacrylate up to high degrees of conversion: Experimental investigation of the diffusion‐controlled polymerization

Abstract

The kinetic model given by Marten and Hamielec that describes the bulk polymerization of methyl methacrylate (MMA) and accounts for diffusion‐controlled termination and propagation was modified to include termination by combination and reaction diffusion and was then tested using isothermal conversion/time and molecular weight data obtained dilatometrically at various temperatures and with three different initiators. For each series of measurements two adjustable parameters were fitted to the conversion/time data. Excellent fits were obtained and the adjustable parameters were found to be the same for all concentration levels of the three initiators and to vary in a simple manner with temperature. The predicted molecular weight averages and molecular weight distributions were in satisfactory agreement with those found experimentally considering the difficulty of measuring high molecular weight PMMA by GPC. This model thus satisfies the specifications for a polymer reactor model that can be used to optimize commercial production systems.

Simulation of radical polymerization of methyl methacrylate at room temperature using a tertiary amine/BPO initiating system

“…This phenomenon was only roughly modeled in some publications 15 since the conversion time dependence was the main parameter studied in diffusioncontrolled polymerization of methacrylate derivatives. 36,37 In our experimental conditions, bimodal distributions can be observed in both experimental SEC results and modeled data ( Figure 9). The experimental and modeled MWD are in rather good agreement with only experimentally a less pronounced population of high molecular weight for high initiator concentration (see ESI for details).…”

Polymerization Processes, 1. Fundamentals

“…For methyl methacrylate, combination and disproportionation are both important at low temperature, with disproportionation becoming the dominant mode at high temperatures [23].…”

“…The sequence of elementary reactions in Equations (22)(23)(24)(25)(26)(27)(28) result in total radical concentrations of the order 10 À9 -10 À5 mol/L for most commercial polymerizations. Since polymer molecules with high molecular masses are produced from the very start of polymerization, the reacting solution can be quite viscous over most of the monomer conversion range.…”

Biodiesel: a green polymerization solvent

“…There are many practical aspect of free radical polymerization modeling including segmental diffusion control model (Mahabadi and O'Driscoll, 1977), the reaction diffusion control model (Stickler et al, 1984), diffusion-controlled k t and its chain length dependency (Russell et al, 1992) which have been summarized by Dube et al (1997) and .…”