First effective nitroxide-mediated polymerization of methyl methacrylate

Bulk methyl methacrylate (MMA) controlled radical polymerization was carried out using two 2,2-diphenyl-3-phenylimino-2,3-dihydroindol-1-yloxyl nitroxide (DPAIO) based alkoxyamines. Whatever the alkoxyamine used, polymerization presents a controlled character, and high conversion can be reached. Polymerization up to 60% conversion, initiated with the nitro para-substituted alkoxyamine 2, showed a linear increase of number-average molecular weight (M-n) vs conversion even at the beginning of the polymerization with the final polydispersity index (PDI) close to 1.4. A reinitiation test onto n-butyl acrylate has shown that even if this nitroxide is not suited for acrylate monomers, the shift of the size exclusion chromatography (SEC)trace proved the poly(methyl methacrylate)-DPAIO macroinitiator (PMMA-DPAIO) obtained had a living character. These results showed that the range of monomers that could be polymerized by nitroxide mediated polymerization (NMP) can still be extended.