CuSO4-catalyzed self-initiated radical polymerization of 2-(N,N-dimethylamino) ethyl methacrylate as an intrinsically reducing inimer

• Published in: Chinese journal of polymer science 2013-08, Vol.31 (8), p.1161-1172
• Main Authors: Sun, Yan, Zhai, Guang-qun
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Condensed Matter Physics; Industrial Chemistry/Chemical Engineering; Polymer Sciences
• ISSN: 0256-7679; 1439-6203
• DOI: 10.1007/s10118-013-1317-5

Since tertiary amines (C α -H) can be oxidized by peroxides and transition metal cations in high oxidation states into C α · radicals to initiate vinylic polymerizations of methacrylates, Cu 2+ and 2-( N,N -dimethylamino)ethyl methacrylate (DMAEMA) form a polymerizable redox initiating pair, in which DMAEMA serves as an intrinsically reducing inimer. CuSO 4 -catalyzed aqueous self-initiated radical polymerizations of DMAEMA were successfully performed at ambient temperature via a continuous Cu 2+ -tertiary amine redox initiation based on catalyst regeneration in the presence of O 2 . The polymerization kinetics was monitored by gas chromatography and the structure of PDMAEMA was characterized by gelpermeation chromatography, nuclear magnetic resonance spectroscopy, laser light scattering and online intrinsic-viscosity analysis. Both the monomer conversion and the molecular weight of PDMAEMA increase with the reaction while the molecular weight distribution maintains rather broad, as the Cu 2+ -DMAEMA redox-initiation leads to linear PDMAEMA chains with terminal methacryloxyl moieties, and the Cu 2+ -PDMAEMA redox-initiation results in branched chains. The branched topology forms and develops only for the high-MW components of the PDMAEMA. Our results provide a facile strategy to prepare branched polymers from such commercially available intrinsically reducing inimers using a negligible concentration of regenerative air-stable catalysts.