Atom Transfer Radical Polymerization of Methyl Methacrylate High Efficiently Initiated by Azo-containing Iniferter

Abstract

Two novel azo-containing iniferters, (4,4′-(diazene-1,2-diyl) bis(4,1-phenylene) bis(2-(diethylca-rbamothioylthio)-2-methylpropanoate (BDCMP) and 4-((4-bromophenyl)diazenyl)phenyl-2-(diethylcarbamothioylthio)-2-methylpropanoate (PDCMP) were synthesized and used successfully as the initiators for atom transfer radical polymerization of methyl methacrylate (MMA). The kinetic plots were first order and the molecular weights of the polymers with narrow molecular weight distributions increased with the monomer conversions. Furthermore, the results showed that the apparent initiation efficiencies (f was close to 0.90 defined as M _n(th)/M _n(GPC)) of BDCMP and PDCMP were both higher than that (f was lower than 0.5) of 2-N,N-(diethylamino)dithiocarboyl-isobutyrate (EDCIB), which was reported previously by us (14). The obtained mono- and bi-functional PMMAs containing azo and N,N-diethyldithiocarbamate (DC) groups were confirmed by ¹H-NMR and ultraviolet absorption spectra, respectively. The block copolymer, poly (methyl methacrylate)-b-polystyrene (PMMA-b-PS), was also successfully prepared via the ATRP chain-extension experiment using the obtained PMMA as a macroinitiator.

Keywords:

• Atom transfer radical polymerization (ATRP)
• azobenzene
• methyl methacrylate, N
• N-diethyldithiocarbamate

Acknowledgments

The financial support of this work by the National Nature Science Foundation of China (No.20574050), the Science and Technology Development Planning of Jiangsu Province (No. BK2007702 and BK2007048), and the Nature Science Key Basic Research of Jiangsu Province for Higher Education (No. 05KJA15008) are gratefully acknowledged.