Zur polymerisation von methylmethacrylat bis zu hohen umsätzen: Experimentelle untersuchungen zur theorie des trommsdorff‐effektes nach cardenas und o'driscoll

Abstract

Abstract The kinetic model given by Cardenas and O'Driscoll, which describes the bulk polymerization of methyl methacrylate (MMA) in the region of the gel effect by the concept of chain entanglements, is extended to the region of the glass effect in accordance with a proposition made by Marten and Hamielec based on the free volume theory. Equations for the calculation of the instantaneous and cumulative molecular weight distributions are derived, too. Dilatometric measurements over the entire conversion range were performed at various temperatures and with three different initiators. For each series of measurements the three adjustable parameters of the extended model were fitted to the time‐conversion data. Contrary to the assumptions, it was then found that at least one of the parameters of the model of Cardenas and O'Driscoll (α 0 ) depends both on the concentration and the type of the initiator. The calculated molecular weight distributions are much broader than the experimental ones. Thus the model of Cardenas and O'Driscoll at its present state does not seem to describe adequately the real polymerization behavior of MMA.