Title: Crosslinking of Cellulose for Improving Cotton Resiliency and Fire Performance
Speaker: Prof. Charles Yang
From: The University of Georgia, USA
Date: Oct. 15, 2013
Abstract:

Cotton combines high wearing comfort with excellent dyeability and high alkali-resistance, thus becomes the most valuable and the most commonly used fiber for clothing. Low resiliency and high flammability are the major disadvantages of cotton in many of its applications. Durable press (DP) finishing, a chemical treatment commonly used by the industry to impart wrinkle-resistance and smoothing drying properties to cotton fabrics, is based on the covalent crosslinking of cellulose on cotton fabrics. We studied the reaction mechanism of crosslinking of cotton cellulose, developed new formaldehyde-free crosslinking systems, and also investigated the mechanism of fabric strength loss as a result of crosslinking.
Cotton is also a highly combustible textile fiber, therefore flame-resistance is a critically important property for cotton and cotton blends. We developed a new FR finishing system for cotton/Nomex blends military fabric based on a hydroxyl-functional organophoaphorus oligomer and a polycarboxylic acid as the crosslinking agent between cotton and the flame retardant. We also found that a polycarboxylic acid, once esterifies cotton cellulose, is able to function as a condensed phase flame retardant for cotton by reducing its peak heat release rate and promoting char formation of the treated cotton. Such treatment of cotton fleece is successful in reducing the flammability of the cotton fleece from "Class 3" to "Class 1" (16 CFR 1610), the legally required flammability ranking for general apparels. Moreover, crosslinking reactions were also used to bond an organophosporus flame retardant to nylon, which became the basis of the flame retardant cotton/nylon blend military fabrics.