Resident postdoctoral research associate.
ESR study of reactions of cellulose initiated by the ceric ion method†
Article first published online: 9 MAR 2003
Copyright © 1966 John Wiley & Sons, Inc.
Journal of Applied Polymer Science
Volume 10, Issue 10, pages 1591–1606, October 1966
How to Cite
Arthur, J. C., Baugh, P. J. and Hinojosa, O. (1966), ESR study of reactions of cellulose initiated by the ceric ion method. J. Appl. Polym. Sci., 10: 1591–1606. doi: 10.1002/app.1966.070101015
Paper presented in part at the IUPAC International Symposium on Macromolecular Chemistry, Tokyo and Kyoto, Japan, September 28–October 4, 1966.
- Issue published online: 9 MAR 2003
- Article first published online: 9 MAR 2003
- Manuscript Received: 2 MAY 1966
The ESR spectra of microcrystalline cellulose and purified cotton cellulose reacted with ceric ammonium nitrate in nitric acid were determined. The effects of the concentration of ceric ion, atmosphere, temperature, and graft copolymerization with acrylonitrile on the rates of formation and decay of radicals in the cellulose molecule were determined under both static and dynamic conditions. Under static conditions, after the desired conditions of reaction, the samples were frozen at –100 or –160°C., and then the concentration of free radicals was determined. Under dynamic conditions ceric ion solution was continuously flowed through the celluloses while these determinations were being made at 25°C. In the presence of oxygen the rate of decay of free radicals was decreased. On initiation of copolymerization reactions with acrylonitrile, there was an increase in radical concentration, then a decrease. Apparently, during graft copolymerization the radical site initially on the cellulose molecule was retained on the end of the growing polymer chain. Then additional ceric ion coordinated with the hydroxyl groups of the cellulose, leading to the formation of additional radical sites. An Arrhenius interpretation of the effect of temperature on the formation of these additional radical sites gave apparent activation energies for radical formation on cotton cellulose as 34 kcal./mole and on microcrystalline cellulose as 29 kcal./mole.