Cottoning on to flame resistance

Clay particles help prevent cotton from burning so readily.

Cotton may be the most important textile fibre for clothing, but it has always suffered from its inherent ability to burn. Now, scientists at the Agricultural Research Service of the US Department of Agriculture (USDA-ARS) have combined cotton fibres with clay particles to produce a textile with enhanced flame-retardant properties.

Leslie White from the ARS Cotton Textile Chemistry Research Unit of the Southern Regional Research Center in New Orleans, Louisiana, dissolved cotton fibres in a solvent (4-methylmorpholine- N-oxide) and then incorporated montmorillonite clay particles into the fibres. Drying the mixture and removing the solvent caused the tiny clay particles to become dispersed and embedded throughout the cotton matrix.

Mixing the clay with the cotton had the desired effect of improving the fabric’s burn resistance. The cotton-clay product’s degradation temperature increased by 45 ?C compared with unbleached cotton.

Not only is this cotton-clay nanocomposite (containing 1-10 per cent clay) natural, but the process by which the two components are joined is considered environmentally friendly, because the solvent used to dissolve the cotton fibres is recyclable and is applied in a closed system.

The resultant material, boasting cotton’s softness and clay’s durability, could some day be used as fabric for protective apparel and as insulation for fire protection in homes, claim the researchers.

Hamish Kidd