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4711780 
Journal Article 
Nitroxide-Mediated Polymerization of Methyl Methacrylate and Styrene with New Alkoxyamines from 4-Nitrophenyl 2-Methylpropionat-2-yl Radicals 
Greene, AC; Grubbs, RB 
2010 
1 
Macromolecules
ISSN: 0024-9297
EISSN: 1520-5835 
43 
24 
10320-10325 
WOS:000285429400024 
The N phenylalkoxyamine N-(1-methyl (1 (4-nitrophenoxy)carbonyl)ethoxy)-N-(1 methyl-(1(4 nitrophenoxy)carbonyl)ethyl)benzenamine (1) was prepared by the addition of 4 nitrophenyl 2-methyl-propionat-2 yl radicals across the double bond of nitrosobenzene and evaluated as an initiator for nitroxide mediated polymerization (NMP) N-Phenylalkoxyamines have not been extensively studied in NMP, though they have shown promise in controlling methyl methacrylate (MMA) polymerization to moderate conversions It is thought that delocalization of the nitroxide radical through the N phenyl substituent may minimize cross disproportionation of the nitroxide with the chain end that has made NMP of MMA difficult Here we show that alkoxyamine 1 is capable of controlling the NMP of MMA to 50% conversion while maintaining narrow molecular weight distributions (M-w/M-n = 1 12-1 30) Additionally, chain extension from the resulting PMMA macroinitators with MMA or styrene allows the formation of diblock copolymers The corresponding N tert-butylalkoxyamine, 2,2 dimethyl 3 (1-methyl-(1 (4-nitrophenoxy)carbonyl)ethoxy) 4-methyl (4(4-nitrophenoxy)carbonyl)ethyl 3 azapentane (2), was synthesized by the addition of 4 nitrophenyl 2 methylpropionat 2-yl radicals across the double bond of 2 methyl 2 nitrosopropane Polymerization of M MA with alkoxyamine 2 was uncontrolled, which suggests the paramount importance of the N phenyl group for MMA polymerizations