Physical Properties of Cotton Reacted with Beta-Propiolactone
1956
Nott, Emilie H. | Grant, James N.
Cotton yarns made from an American upland cotton were pre-extracted with either acetone or monoethanolamine. In the present investigation they were reacted with beta- propiolactone either in the presence of xylene by the reflux method, or in the presence of either 8 or 15% sodium hydroxide by the alkali method to secure add-ons in weight of up to 36.9.% A new type of modified cotton produced by graft polymerization was attained by the reaction. Certain physical properties of the fibers and yarns were meas ured. The changes in most properties were found to be associated with the pretreatment, the method of reaction, and the add-on of beta-propiolactone. While tenacities of fibers and yarns generally decreased progressively with increase of beta-propiolactone add-on, the decreases are due principally to the add-on of the polymer. Density decreased linearly with add-on but varied depending on pre-extraction solvents and methods of treatment used. The rate of degradation of the cellulose by heat was slightly greater in the re acted yarns than in the untreated. Frictional resistance of yarns against steel was in creased for yarns reacted with beta-propiolactone in the presence of xylene, but un affected when the alkali method was used. Electron micrographs show the polymer on the surface of those fibers reacted in xylene but very little on the surface of those re acted in alkali. Elastic recovery increased 11 to 13% with beta-propiolactone treatments.
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