Formaldehyde as a Protective Agent for Wool

Abstract

1. The degradation of a formaldehyde-wool, in one hour at 100° C. by 50 volumes of water, 0.25, 0.50 or 0.75 N hydrochloric acid, in 10 hours at 25° C. by 50 volumes of water or 6 N acid, in 10 hours at 40° C. by 50 volumes of water, 0.05, 0.10, 0.15, 0.20, 0.30 or 0.40 N sodium hydroxide, and in five minutes at 15° C. by 50 volumes of 38% sodium hydroxide, has been measured by the weight, nitrogen, total sulfur, sulfate sulfur, wet strength and elongation at breaking load of the residual keratin after rinsing. 2. The formaldehyde-wool lost the same weight, four % less nitrogen, and 17% more sulfur than the wool during one hour at 100° C. in 0.75 N acid. In 0.25 N acid the wool lost 88% and the formaldehyde-wool 56% in wet strength ; at 0.5 N these values were 100 and 75. 3. The percentage losses by wool (a) and formaldehyde-wool (b) after 10 hours at 40° C. in 6 N acid were: Weight (a, 5 ; b, 1.4), nitrogen (a, 5; b, 1), total sulfur (a, 0; b, 11), wet strength (a, 75 ; b, 50). 4. Residues of the formaldehyde-wool from 10 hours' treatment in dilute alkali at 40° C. were nearly constant in total nitrogen, greater in weight than those of wool, and of a measurable wet strength at 0.2 N, a concentration four times that beyond which the untreated fabric failed. The non-sulfate sulfur of the residual formaldehyde-wool, a decreasing logarithmic function of the concentration of alkali, y = axB, coincided with that of wool at 0.05 and 0.1 N alkali. 5. The percentage losses of non-sulfate sulfur, weight, and wet strength in concentrated sodium hydroxide were the same for the formaldehyde-treated as for the untreated wool ; the total nitrogen of the formaldehyde-wool was not changed by mercerization.