Polymerization of methyl methacrylate through ionizing radiation in CO2-based dense systems.

Herein, we report the use of ionizing radiation to induce a dispersion poly merization reaction in dense CO2. As a model system, the polymerization of methyl methacrylate in the presence of poly(dimethylsiloxane) stabilizers w as investigated. It was demonstrated that the dose plays the key role in th e progress of the reaction and in the morphology of the resulting polymer. Dispersion polymerization carried out in the presence of mono- and bifuncti onalized surfactants gave differently structured polymers. The polymers obt ained have been characterized by scanning electron microscopy, solubility t ests, and gel permeation chromatography, and the molecular structure has be en related to dynamic mechanical behavior in the melt state.