title: Use of solvent effects to improve control over nitroxide-mediated polymerization of isoprene.
abstract: The use of 1,4-dioxane or pyridine as solvents for the polymerization of isoprene mediated by the acid-functional SG1-based alkoxyamines N-(2-methylpropyl)-N-(1-diethylphosphono-2,2-dimethylpropyl)-O-(2-carboxylprop-2-yl)hydroxylamine (BlocBuilder MA) and N-(2-methylpropyl)-N-(1-diethylphosphono-2,2-dimethylpropyl)-O-(2-carboxyleth-2-yl)hydroxylamine results in an increase in the rate of consumption of the initiator and narrower molecular weight distributions of the resulting polymer. In pyridine, an improved control of the polymerization was also obtained for a non-acid-functional initiator, and the overall rate of polymerization increased. These effects are likely to be the result of the disruption of intramolecular hydrogen bonding and, in the case of pyridine, stabilization of the polar SG1 free radical.
authors.affiliation: Laboratoire de Physico-Chimie, Pharmacotechnie et Biopharmacie, Univ Paris-Sud, UMR CNRS 8612, Faculté de Pharmacie, 5 rue Jean-Baptiste Clément, F-92296 Châtenay-Malabry cedex, France.
authors.forename: Simon
authors.initials: S
authors.lastname: Harrisson
authors.forename: Patrick
authors.initials: P
authors.lastname: Couvreur
authors.forename: Julien
authors.initials: J
authors.lastname: Nicolas
mesh_terms: D000438:Alcohols / Q000737:chemistry; D000588:Amines / Q000737:chemistry; D002070:Butadienes / Q000737:chemistry*; D019256:Cadmium Chloride / Q000737:chemistry; D002384:Catalysis; D004146:Dioxanes / Q000737:chemistry*; D045782:Hemiterpenes / Q000737:chemistry*; D006860:Hydrogen Bonding; D008970:Molecular Weight; D009589:Nitrogen Oxides / Q000737:chemistry*; D010420:Pentanes / Q000737:chemistry*; D058105:Polymerization; D011725:Pyridines / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry*
chemical_list: D000438:Alcohols; D000588:Amines; D002070:Butadienes; D004146:Dioxanes; D045782:Hemiterpenes; D009589:Nitrogen Oxides; D010420:Pentanes; D011725:Pyridines; D012997:Solvents; C059688:alkoxyl radical; C005059:isoprene; C039900:nitroxyl; D019256:Cadmium Chloride; C025223:1,4-dioxane; C023666:pyridine