IONIC CROSSLINKING OF COTTON

Abstract

Cellulose crosslinking is a very important textile chemical process, and is the basis for a vast array of durable press and crease-resistant finished textile products. Formaldehydecontaining N-methylol crosslinkers give fabrics desirable properties of mechanical stability (e.g., crease resistance, anti-curl, shrinkage resistance, durable-press), but also impart a loss of strength and the potential to release formaldehyde, a known human carcinogen. Other systems, such as polycarboxylic acids, have been tested with varying degrees of success. We have developed methods of forming ionic crosslinks that provide outstanding performance in crease angle recovery while completely retaining the strength of treated goods, without the potential to release any reactive materials of low molecular weight, such as formaldehyde. Our work is based on the reactions of cellulose with materials that impart an ionic character to the cellulose; e.g., chloroacetic acid for negative charges or 3-chloro-2-hydroxypropyl trimethyl ammonium chloride for positive charges. These reactions produce ionic celluloses that can then absorb a polyionic material of opposite charge to form crosslinks. Cellulose treated with cationized chitosan after carboxymethylation showed significant increases in crease recovery angles without a loss of strength.