%0 Journal Article
%T Elucidation of Acceleration Mechanisms by a Photosensitive Onium Salt for Nitroxide-Mediated Photocontrolled/Living Radical Polymerization
%A Eri Yoshida
%J Open Journal of Polymer Chemistry
%P 47-55
%@ 2165-6711
%D 2014
%I Scientific Research Publishing
%R 10.4236/ojpchem.2014.43006
%X <p style=\"text-align:justify;\">
	<span style=\"font-size:10.0pt;font-family:&quot;\"><span style=\"font-family:Verdana;font-size:12px;line-height:1.5;\">The acceleration mechanisms by a photosensitive onium salt for the
nitroxide-mediated photocontrolled/living radical polymerization (photo-NMP)
were determined. The photo-NMP of methyl methacrylate was performed by
irradiation at room temperature using 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl
(MTEMPO) as the mediator and (2RS, 2¡¯RS)-azobis(4-methoxy-2,4-dimethylvaleronitrile)
as the initiator. The polymerization was accelerated in the presence of (4-</span><i><span style=\"font-family:Verdana;font-size:12px;line-height:1.5;\">tert</span></i><span style=\"font-family:Verdana;font-size:12px;line-height:1.5;\">butylphenyl)diphenylsulfonium
triflate (</span><i><sup><span style=\"font-family:Verdana;font-size:12px;line-height:1.5;\">t</span></sup></i><span style=\"font-family:Verdana;font-size:12px;line-height:1.5;\">BuS) to produce
a polymer with a molecular weight dis</span><span style=\"font-family:Verdana;font-size:12px;line-height:1.5;\">tribution
as narrow as the polymerization in its absence. (</span></span><span style=\"font-size:12px;font-family:Verdana;line-height:1.5;\">¡À</span><span style=\"font-size:12px;font-family:Verdana;line-height:1.5;\">)-Camphor-10-sulfonic acid or 2-flu</span><span style=\"font-size:10.0pt;font-family:&quot;\"><span style=\"font-family:Verdana;font-size:12px;line-height:1.5;\">oro-1-methylpyridinium </span><i><span style=\"font-family:Verdana;font-size:12px;line-height:1.5;\">p</span></i><span style=\"font-family:Verdana;font-size:12px;line-height:1.5;\">-toluenesulfonate
had no effect on the polymerization speed, suggesting that </span><i><sup><span style=\"font-family:Verdana;font-size:12px;line-height:1.5;\">t</span></sup></i><span style=\"font-family:Verdana;font-size:12px;line-height:1.5;\">BuS did not serve as the photo-acid generator for the
photo-NMP. It was found that the acceleration of the polymerization was based
on the electron transfer from MTEMPO into </span><i><sup><span style=\"font-family:Verdana;font-size:12px;line-height:1.5;\">t</span></sup></i><span style=\"font-family:Verdana;font-size:12px;line-height:1.5;\">BuS
in the excited state to temporarily generate a free radical propagating chain
end and an oxoaminium salt (OAS), the one-electron oxidant of MTEMPO. This
electron transfer mechanism was verified on the basis of the fact that the
photo-NMP in the presence of </span><i><sup><span
%K Photocontrolled/Living Radical Polymerization
%K Acceleration Mechanisms
%K Electron Transfer
%K (4-tert-Butylphenyl)Diphenylsulfonium Triflate
%K 4-Methoxy-2
%K 2
%K 6
%K 6-Tetramethylpiperidine-1-Oxyl
%K Oxoaminium Salt
%U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=48731