Deuterium-Hydrogen-Exchange Accessibility of Cellulose by Use of D218O and Mass Spectroscopy.

A method for measuring the deuterium-hydrogen-exchange accessibility of cellulose and of chemically modified cellu luloses, based on the use of D218O and mass spectroscopy, has been applied to a variety of well characterized samples. The expected correlation of the values obtained with moisture regain determined at 65% relative humidity and 21° was found for unsubstituted celluloses, but not for substituted celluloses having covalently attached oxymethylene groups. It is postulated that this lack of correlation for the substituted celluloses is due to association of water with the oxymethylene groups, thus leading to higher moisture regain values than predicted from the deuterium-hydrogen-exchange values. A good correlation, however, was found between the deuterium accessibility of these substituted samples and their alkali centrifuge values. The effect on deuterium accessibility of heating purified cotton cellulose with D218O in sealed capillary tubes was also investigated. [ABSTRACT FROM PUBLISHER]