A detailed analysis of a recently developed batch polymerization process is presented. The new technique, designed for the production of high purity polymers (e.g. far biomedical purposes), consists aia suspension polymerization in which the suspending phase is transformed into a gel before initiating polymerization. A detailed first principles model of the process is developed. Both experimental and theoretical results are for polymerization of methyl methacrylate in an aqueous phase, which has been gelled by the addition of agarose;The analysis is focused on the sensitivity of the system with respect to operating conditions, the kinetic parameters, and the heat. transfer properties, The system thermal stability is a primary concern, because of the lack of agitation and the possible instability of the gelled phase at high temperature. Sensitivity to the maximum temperature is therefore examined, Parameters that can increase the polymerization rate, such as the initial initiator concentration, and many of the kinetic constants are round to affect mainly the time at which the maximum temperature appears, but not significantly its value. No problem of gel instability was found. An instability may appear only if the jacket temperature or the water to methyl methacrylate ratio is significantly varied. The model developed, and its use to compute system sensitivities, has proven to be valuable for reactor scale-up and process understanding and optimization.