N-Methylolpolyethyleneureas-Reagents Yielding Durable-Press Cotton Fabrics with Improved Retention of Strength-Abrasion Resistance

Abstract

Polyethylenimines, degree of polymerization = 1-5, 7, and 14, were reacted with urea to form oligomeric noncyclic analogues of ethyleneurea that were subsequently treated with formaldehyde to yield the corresponding N-methylol polyethyleneureas. All seven of these oligomers were shown to undergo facile acid-catalyzed gelation at 50°C. They were applied to cotton twill with Al₂(OH)₂Cl.2NH₂O as the crosslinking/polymerization catalyst. The textile properties of these fabrics were compared with those of fabrics treated with ten conventional crosslinking reagent/catalyst systems. The fabrics finished with the N methylolpolyethyleneureas had significantly higher than conventional levels of retained strength and abrasion resistance at comparable durable-press appearance ratings. The best balance of properties oc curred when the degree of polymerization of the N-methylolpolyethyleneurea was in the 2-4 range. Microscopical studies indicated a more open, less tightly cross-linked structure in the N-methylolpolyethyleneurea fabrics relative to fabrics treated with conventional reagents. The attractive performance properties conferred by the N-methylolpolyethyl eneureas are attributed to the ability of the reagent to penetrate the cotton fiber, undergo facile polymerization and moderate cellulosic crosslinking, deposit small amounts of resin on fiber surfaces, and yield modified fibers that are more open and less tightly crosslinked than are conventionally crosslinked fibers.