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Nitroxide‐Mediated Radical Polymerization in Microemulsion
Author(s) -
Wakamatsu Junpei,
Kawasaki Masahiro,
Zetterlund Per B.,
Okubo Masayoshi
Publication year - 2007
Publication title -
macromolecular rapid communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.348
H-Index - 154
eISSN - 1521-3927
pISSN - 1022-1336
DOI - 10.1002/marc.200700576
Subject(s) - nitroxide mediated radical polymerization , cationic polymerization , monomer , microemulsion , polymer chemistry , polymerization , micelle , radical polymerization , polymer , chemistry , styrene , pulmonary surfactant , copolymer , organic chemistry , aqueous solution , biochemistry
Nitroxide‐mediated polymerizations of styrene in microemulsion have been carried out at 125 °C using the cationic surfactant tetradecyltrimethylammonium bromide and the nitroxides 2,2,6,6‐tetramethylpiperidinyl‐1‐oxy (TEMPO) and N ‐ tert ‐butyl‐ N ‐[1‐diethylphosphono‐(2,2‐dimethylpropyl)] nitroxide (SG1). TEMPO‐mediated polymerizations were extremely slow, with large particles ( d n = 39–129 nm) and broad molecular weight distributions (MWDs). The origin of the broad MWDs was likely significant alkoxyamine decomposition and differing diffusion rates of monomer and low MW alkoxyamines (and nitroxide) between monomer‐swollen micelles and polymer particles. SG1‐mediated polymerizations proceeded at higher rates, resulting in nanoparticles ( d n = 21–37 nm) and lower $\overline M _{\rm w} /\overline M _{\rm n}$ than for TEMPO.