Modification of Wool by the Application of Linear Synthetic Polyamides

Abstract

The effect of surface deposits of nylon and N-substituted nylons on the abrasion-resistance and felting shrinkage of wool has been determined. N-methoxymethyl nylons are much more effective than nylon itself, when applied from solution, in increasing the abrasion-resistance of wool fabric, but not in decreasing the felting shrinkage of the fabric. If the N-methoxymethyl nylon is first applied to the wool fabric from alcoholic solution and then hydrolyzed in situ by approximately 2N HCl, the polymer is found to confer non-felting properties on the wool. A deposit of approximately 3% by weight of polymer has been found to eliminate entirely the felting shrinkage of wool fabric under the conditions of test. The optimum degree of substitution of the nylon for the production of non-feltability is between 5% and 6% combined formaldehyde, which corresponds to between 20% and 24% —NH groups substituted. The effectiveness of these polymers in increasing abrasion-resistance and decreasing felting shrinkage is explained on the basis of their adhesion to and covering power on the wool fiber.