Understanding of formation of irreversible Hbonds in cellulose is important in a number of fields. For example, fields as diverse as pulp and paper and enzymatic saccharification of cellulose are affected. In the present investigation, the phenomenon of formation of irreversible H-bonds is studied in a variety of celluloses and under two different drying conditions. Avicel and amorphous celluloses along with those from wood and tunicate were investigated. Sample deuteration was used to form deuterated Hbonds which provided valuable information. Samples of the deuterated and non-deuterated materials were evaluated in dried state by means of ATR IR and 1064 nm FT-Raman spectroscopies. Additionally, quantitative information on cellulose accessibility at the molecular level was obtained using a newly developed Raman method that required sampling under D2O. Further, to investigate irreversible nature of the H-bonds, the deuterated materials were treated with water. Irreversible H-bonds or irreversible deuterations were characterized by measurement of the residual intensity in the OD stretch region of the H2O-exchanged samples. Moreover, the formation of irreversible H-bonds resulted in reduced accessibility to water, as measured by the before-and after-drying measurements of the increase of band intensity at 1380 cm-1.
Agarwal, Umesh P.; Ralph, Sally A.; Reiner, Rick S.; Stark, Nicole M. 2015. Formation of Irreversible H-bonds in Cellulose Materials. Proceedings of the 18th ISWFPC (International Symposium on Wood, Fiber, and Pulping Chemistry) held in Vienna (Sept 9 -11, 2015). 2015; pp. 18-21.