The Efficiency of Reaction Between Reactive Fluorescent Whitening Agents and Wool

Potential fluorescent whitening agents (FWAs) containing halogen atoms which, intramolecularly quench fluorescence have been synthesised and applied to wool in a number of ways. Application by cold pad-batch methods revealed that the complete displacement of all halogen atoms by nucleophilic groups in wool did not take place. Treatment of these materials with morpholine, sodium carbonate or water was necessary to develop the full potential fluorescence yield of the FWA on the fabric. The fluorescence of FWAs can be quenched by the heavy atom effect, as shown by the fact that no fluorescence was observed when commercial FWAs were applied to brominated wool. If the FWA-treated brominated fabrics were subjected to a reduction treatment then the bromine atoms were removed and the fluorescence of the FWA restored