No abstract

Samples of vinylated cotton slivers with DS (degree of substitution) values of about 0.05 and below were found to be soluble in cupriethylenediamine hydroxide solution. Vis cosity determinations indicated D.P.'s of 97 to 586 which were considerably lower than that of the starting cotton (about 3000). Samples with higher D.S. values were all insoluhle in the reagent indicating at least a small amount of cross-linking. X-ray diffraction patterns made from the vinylated cotton slivers and cloth showed a nearly complete loss of cellulose crystallinity at D.S. values above about 0.10. This indicates good penetration of the crystalline regions by the catalyst and acetylene in the vinylation reaction. Good crease recovery angles were obtained by heating a sample of vinylated cotton print cloth ( D.S. = 0.21 ) with acidic catalysts. Most samples had breaking strength measurements 55-85% of the control cloth and showed 20-50% elongation at break.

Cotton cellulose in the form of slivers and print cloth was successfully vinylated with acetylene without destroying the fiber structure. D.S. (degree of substitution) values up to 0.70 were achieved in vinylation reactions at 120° C, using potassium hydroxide as the catalyst. The important variables in the vinylation reaction were found to be the catalyst and its concentration, the moisture content of the catalyst-impregnated cotton, solvent, acetylene pressure, time, and temperature. The weight of vinylated cotton re covered was 95% to 100% of the weight of the cotton used in the case of the best vinylation conditions, and the vinylated cotton showed good storage stability.