The copolymerisation of methyl and ethyl methacrylate in supercritical carbon dioxide

This paper reports the free radical dispersion copolymerisation of methyl a nd ethyl methacrylate in supercritical carbon dioxide. The polymerisation u ses a poly(dimethyl siloxane) monomethacrylate macromonomer as the stabilis er. A range of different reaction times was investigated in order to probe the amount of each monomer incorporated in the copolymer. Analysis by H-1 N MR spectroscopy reveals that the monomers behave as in conventional solvent s to form a random copolymer. The effect of varying the initiator concentra tion (initiator 2,2'-azobisisobutyronitrile, AIBN) on the composition and m olecular weights of the resultant copolymers has also has been studied.