| Abstract: | A model is proposed for the radical-induced polymerization of methyl methacrylate which combines concepts given in the literature. Consecutive steps for diffusion and reaction are used for both the propagation and the termination process, and the termination at higher degrees of conversion is dominated by reaction diffusion as described by Buback. The diffusional contributions to the processes are semi-empirically based on the free-volume theory, following a suggestion made by Marten and Hamielec, and the diffusion of the macroradicals is assumed to depend on the instantaneous molar mass (as representative for their chain length) and on the cumulative molar mass (representing the matrix of the dead polymer). With one fixed and four adjustable parameters, the model successfully not only describes the bulk polymerization but also takes account of the presence of solvent, chain transfer agent and pre-polymer. |
