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Density of Modified Cottons Determined with a Gradient Column

Orr, Rollin S., Weiss, Louis C., Moore, Harry B., Grant, James N.
Textile research journal 1955 v.25 no.7 pp. 592-600
acetylation, air drying, cellulose, cellulosic materials, cotton, equations, fabrics, hydrolysis, mercerization, rapid methods, solvents, textile fibers
A rapid method which compares favorably in accuracy with that of slower methods for measuring the density of cellulosic materials with a gradient column is described. Densities of several cottons before and after chemical modification by partial acetylation, carboxymethylation, aminization, and mercerization are given. Per cent acetyl can be expressed as a function of density in a linear empirical equation over a range of 13 to 42% acetyl with a precision of ± 2%. Density measurements of decrystallized, ball-mill ground, and acid hydrolyzed cottons were in agreement with the generally accepted con cept of the crystalline-amorphous cellulose phase composition in these materials. Cotton from which water was removed by solvent exchange was found to have a high density before, and a low density after, air drying.