The Interaction of Various Organic Liquids with Cellulose Acetate Fibers as Detected by Specific-Gravity Measurements

Abstract

The pycnometer liquid displacement method of determining the specific gravity of solids has been applied to the study of the rate and the extent of penetration of a large variety of pure liquids into cellulose acetate yarn. Various members of the homologous series of aromatic and aliphatic alcohols, aldehydes, ketones, ethers, esters, halogens, nitriles, phthalate esters, nitro- compounds, and hydrocarbons were used. The maximum apparent specific gravities obtained for a Celanese yarn were found to be a function of the polar groups on the molecules of the liquid medium, as well as of their size and shape. These values range from 1.306 at 20° C with carbon tetrachloride to 1.415 with n-heptaldehyde. A hydrogen-bonding mechanism is suggested to explain the manner by which the liquid- medium molecules penetrate and solvate the yarn. Several applications of this technique and the resultant data are indicated.