In this study, the application of reaction calorimetry, an efficient tool to obtain kinetic and safety data, is presented on the free radical dispersion polymn. of MMA in scCO2. The effect of three major parameters with respect to the reaction evolution are studied, namely of stirrer type and stirring speed, the monomer and CO2 concn. and the stabilizer concn. The effective formation of the dispersion as well as the balance between the polymer formed in the continuous phase or inside the particles are key features of this anal.