A COMMERCIAL SYNTAN AS AN ANIONIC DYE-RESIST AGENT FOR WOOL

The uptake of a commercial syntan by wool serge was found to increase with decreasing application pH, indicating that ion-interaction contributes to syntan-fibre substantivity; adsorption of the syntan also increased with decreasing liquor ratio, possibly as a result of syntan aggregation. Uptake of the tanning agent followed a BET mechanism, suggesting that adsorption involves the formation of multi-layers and that forces of interaction other than ion-ion contribute to syntan adsorption. Treatment with the syntan imparted to wool a low degree of resistance towards uptake of two hydrophobic anionic dyes, but a high resist effectiveness towards adsorption of four hydrophilic anionic dyes when untreated wool, and wool which had been treated with the syntan, were dyed in competition. Syntan desorption occurred during dyeing, indicating that the tanning agent is relatively weakly bound to the fibre; the desorbed syntan exerted a restraining effect on the uptake of all six dyes used.