A universal dye for fibres:-
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A universal dye for fibres
It would clearly be a great advantage for the industry to be able to dye all fibres with the same type of dye and some research has been ongoing in this area using disperse dyes. It cotton/ polyester or wool/ polyester blends are to be dyed with disperse dyes then it is important that the natural fibre components are modified with a suitable auxiliary, which covalently incorporates a disperse dye site. It has been found that suitable fibre reactive auxiliaries can be prepared that may be include in disperse dyebaths to selectively modify the natural fibers. In the case of sulphatoethylsuphone derivatives, lewis and WDI claimed a type of water-soluble arylating agent.
If the above compound were included in a wool dyebath containing commercially available disperse dye and the dyebath set at pH 6.5, then the wool could be satisfactorily dyed with the disperse dye on raising to the boil and boiling for an hour. At this pH the sulphato-ethylsulphone derivative is absorbed as a colourless acid dye, while at high temperatures b-elimination to the vinylsulphone derivative occurs and the agent then reacts with the fibre to covalently incorporate additonal aryl groups enhance disperse dye substantivity by providing sites that interact with aryl residues in the disperse dye. Hydrophobic and p-p interactions are especially relevant in this context.
