Experimental Evaluation of the Lateral-Order Distribution in Cellulose

Abstract

The lack of agreement among various crystallinity and accessibility methods for cellu losic materials is explained in terms of the lateral-order distribution concept. A new definition of the order function is proposed which is more in keeping with recent infrared evidence showing that celluloses differ in distribution of hydrogen bond strengths rather than in actual number of hydrogen bonds. Some of the physical and chemical methods which can give empirical-order distribu tion information for native and regenerated samples are reviewed critically and some data are compared with results based on conventional crystalline-amorphous delineation.

Microbial Cellulose Utilization: Fundamentals and Biotechnology

“…The degree of departure from crystallinity is variable and has led to the notion of a "lateral order distribution" of crystallinity, which portrays a population of cellulose fibers in statistical terms as a continuum from purely crystalline to purely amorphous, with all degrees of order in between (427). In addition to the crystalline and amorphous regions, cellulose fibers contain various types of irregularities, such as kinks or twists of the microfibrils, or voids such as surface micropores, large pits, and capillaries (63,127,178,428).…”

Cellulose

“…Moisture regain, hydrolysis experiments, heat ofmer- cerization, formic acid esterification, swelling and density measurements, and deuterium exchange are methods widely used to determine the accessi bility of cellulose (122). Moisture regain, hydrolysis experiments, heat ofmer- cerization, formic acid esterification, swelling and density measurements, and deuterium exchange are methods widely used to determine the accessi bility of cellulose (122).…”

“…The dashed lines show order levels at which moisture regain and hydrolysis methods distinguish between crystalline and accessible material(122). The dashed lines show order levels at which moisture regain and hydrolysis methods distinguish between crystalline and accessible material(122).…”

Accessibility and Reaction Sites in Cotton

“…They include moisture regain [5,30] , infrared deuteration [11. 12, 13, 16, 28], formylation [ 18,21,24], iodine sorption [26], acid hydrolysis [20,23,25,27], and periodate~oxidation [ 2,6,29 ] . ' A series of cotton and partially methylated cotton fabrics have been examined by these techniques and the results obtained have been compared.…”