Hydrogen bonding on accessible surfaces of cellulose from various sources and relationship to order within crystalline regions

Abstract

Celluloses from a variety of common sources were analyzed for availabilities of O(2)H, O(3)H, and O(6)H in order to estimate the extent of hydrogen bonding on accessible fibrillar surfaces. Celluloses from flax, ramie, sisal, and wood (both cellulose I and II from wood) together with liquid NH3‐swollen cotton and NaOH‐swollen cotton (cellulose II) had relative availabilities similar to those of native cotton. Celluloses from Valonia centricosa and in rayon samples stood apart from each other and from the “cotton family.” The difference between Valonia and cotton celluloses appears to result, in addition to the accepted smaller, less perfect crystallites in cotton, from an O(2)H hydrogen bond which is likely the intramolecular bond between O(2)H and O(6′)H that is present in Valonia and absent in cotton. Rayon samples also showed evidence of similar bonds involving O(2)H on accessible surfaces. Since the regenerated rayons had relative availabilities different from those of mercerized cotton and wood cellulose samples, it is proposed that chain packing arrangements are not the same in these two types of cellulose II.

Moisture sorption isotherms for paper and paperboard in food chain conditions

“…1.8 molecules of waterbound/celluboise unit. It was stated that this was in good agreement with Rowland and Howley, 43 who determined that 1.5 hydroxyl sites/celluboise unit were 'available'.…”

Human neutrophil elastase peptide sensors conjugated to cellulosic and nanocellulosic materials: part I, synthesis and characterization of fluorescent analogs

“…for tunicin whiskers of 0.095 were derived (Habibi et al 2006). However, Eyley and Thielemans discuss the importance of C2 hydroxyl reactivity considerations (Rowland and Howley 1988) in addition to C6 hydroxyls and designate a factor of 1.5 times the number of anhydroglucose units to calculate D.S. on the surface of nanocrystals (Eyley and Thielemans 2011), which may account for experimentally achievable D.S levels as high as 1 or greater.…”

Tailoring nanofibrillated cellulose through sonication and its potential use in molded pulp packaging

“…However, the hydroxy group at C6 in the repeating unit of cellulose is expected to be the most reactive site for the reaction, since only C6 hydroxy are oriented outwards from the surface of the nanofibers [32]. Between secondary hydroxy groups of C2 and C3, the secondary hydroxy group of C2 might also have a higher possibility to participate in the reaction than that of C3 as a result of the intramolecular hydrogen bonds formed at the position of C3 hydroxy groups [33].…”