Fixation involving a phosphonic acid group
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Fixation involving a phosphonic acid group:-
The fixation of a phoshonic acid reactive dye to cellulose takes place under acidic conditions in the presence of cyanamide or a carbodiimide, as shown in Figure. In this case, a competing hydrolysis reaction does not occur. While carbodiimide undergoes a side reaction resulting in modest dye fixation levels, high fixation values can be achieved by using cyanamide.
