Modification of Wool by the Application of Linear Synthetic Polyamides

Abstract

The effect of surface deposits of N-hydroxymethyl polyhexamethylene adipamide on the felting shrinkage of wool has been determined. These polymers resemble the N-methoxymethyl poly amides in that the polymer itself is not particularly effective in preventing felting shrinkage of wool, but when the substituted polymer is applied to wool fabric and then converted to the un substituted polyamide on the fabric, its effectiveness in reducing felting shrinkage is very much increased. A deposit of approximately 3% by weight of polymer on the fabric has been found to eliminate entirely felting shrinkage of the fabric under the test conditions. The optimum degree of sub stitution of the polyamide for production of non-feltability is similar to that found for the N- methoxymethyl derivatives— vi., between 20% and 25% -NH groups substituted. The N-hydroxymethyl polyamides can be converted to the unsubstituted polymers either by hydrolysis—e.g., with acids—or by heating in air.