Cellulose fibres may be dyed with reactive dyes in the absence of added electrolyte under neutral to slightly acidic conditions provided the fibre is modified to include cationic sites. The effect of amine substitution has been examined in detail using the activated substrate prepared by the reaction of cotton with N‐methylolacrylamide. Dyes containing pendant aliphatic amino groups were also prepared and their reactivity towards the pre‐activated cotton substrate assessed.

Pretreatment of cotton with the polyamide‐epichlorohydrin resin Hercosett 125 produces a fibre that may be dyed with selected reactive dyes under neutral pH conditions in the absence of salt and with high fixation efficiency. The physical and mechanical properties of the modified cotton, the colour fastness of the reactive dyeings and mechanistic implications are also discussed.

Covalently binding dyes through reactions between commercially available bi-functional crosslinking agents, wool and aminoethylaminotriazinyl dyes is discussed. In particular, dye fixation, levelness and fastness properties have been assessed and shown to be very promising. The proposed system offers the dyer the opportunity to achieve covalent bonding of the dye to the fibre in a controlled manner, thus ensuring good levelness.

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