Publication

Synthesis of fluorinated alkoxyamines and alkoxyamine-initiated nitroxide-mediated precipitation polymerizations of styrene in supercritical carbon dioxide

Magee, Christopher
Earla, Aruna
Petraitis, Jennifer
Higa, Chad
Braslau, Rebecca
Zetterlund, Per B.
Aldabbagh, Fawaz
Citation
Christopher Magee, Aruna Earla, Jennifer Petraitis, Chad Higa, Rebecca Braslau, Per B. Zetterlund and Fawaz Aldabbagh (2014) 'Synthesis of fluorinated alkoxyamines and alkoxyamine-initiated nitroxide-mediated precipitation polymerizations of styrene in supercritical carbon dioxide'. Polymer Chemistry, 5 :5725-5733.
Abstract
TIPNO (2,2,5-trimethyl-4-phenyl-3-azahexane-3-nitroxide)-alkoxyamine was found to give reasonably controlled/living nitroxide-mediated (NMP) precipitation polymerizations of styrene in supercritical carbon dioxide (scCO(2)). In contrast under the same conditions, the analogous SG1 (N-tert-butyl-N-(1-diethylphosphono-2,2-dimethylpropyl)nitroxide)-alkoxyamine gave higher rates of polymerization and inferior controlled/living character. The circumvention of the requirement for excess free (nitroxide](0) allowed the study of nitroxide partitioning effects in scCO(2) for three newly synthesized fluorinated alkoxyamines. Two alkoxyamines dissociated into scCO(2)-philic fluorinated TIPNO-nitroxide derivatives, while another contains a similar sized fluorinated "foot". Despite the increased steric bulk about the N-O bond for the novel fluorinated alkoxyamines, all polymerizations proceeded at a similar rate and level of control to the TIPNO system in solution (toluene). PREDICI simulations for the styrene/TIPNO system are used to support extensive partitioning effects observed in scCO(2) for the fluorinated alkoxyamines.
Funder
Publisher
Royal Society of Chemistry
Publisher DOI
10.1039/C4PY00757C
Rights
Attribution-NonCommercial-NoDerivs 3.0 Ireland