Many models have been developed to describe the kinetics of the free radical polymn. of Me methacrylate (MMA). However, they are restricted to low temps., e.g., below the glass transition temp. of the polymer, Tg. In this work, kinetics of bulk and soln. polymn. of MMA were detd. by differential scanning calorimetry (DSC) for temps. above Tg, i.e. 130-165 DegC. On the basis of our own exptl. results (high temps.) and those published in the literature (low temps.), it has been shown that with small modifications, the model of Achilias and Kiparissides gives a good description of kinetics for a temp. range from 20 to 165 DegC. Furthermore, all parameters appearing in the diffusion-limited part of the kinetic rate consts. have a clear phys. meaning and can be evaluated in terms of phys. and transport properties of the reacting species. [on SciFinder (R)]