TEMPO-mediated oxidation of cellulose III.
Various cellulose samples converted into cellulose III by two different ammonia treatments, either liquid or gaseous, were reacted with catalytic amounts of 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO), sodium hypochlorite, and sodium bromide in water. A substantial increase in the reactivity of cellulose III samples was observed in comparison to those in cellulose I, and a relationship between oxidation conditions and cellulose primary hydroxyl groups accessibility was directly established. For the characterization, we have used several methods, mainly (13)C NMR, methylene blue adsorption, FTIR, and conductometric titration. In all samples, the primary alcohol groups were selectively oxidized into carboxyl groups, provided the sodium hypochlorite is added dropwise and the reaction is performed at constant pH 10.
da Silva Perez
Denilson
D
Centre de Recherches sur les Macromolécules Végétales, (CERMAV-CNRS), Université Joseph Fourier, BP 53, 38041, Grenoble Cedex 9, France.
Montanari
Suzelei
S
Vignon
Michel R
MR
D002264:Carboxylic Acids; D002482:Cellulose / Q000737:chemistry*; D003497:Cyclic N-Oxides / Q000737:chemistry*; D007700:Kinetics; D019906:Nuclear Magnetic Resonance, Biomolecular; D010084:Oxidation-Reduction; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared
D002264:Carboxylic Acids; D003497:Cyclic N-Oxides; D002482:Cellulose; C003959:TEMPO