Reaction mechanism of reactive dye and cellulose

Reaction mechanism of dye and cellulose

The bonding behavior of dye and cellulose are mentioned below:

1.  Hydroxyl group of cotton polymer takes part in reaction with reactive group of   dye

2. Reactive group of dye react preferably with the hydroxyl group of cellulose than that of water.

3. The activation energy of dye – water reaction is 16.4 – 26.2 kcal and that of dye cellulose is 9.2 – 15.8 kcal. As the latter is less, so that occurs predominately.  

4.Higher activation energy causes slower reaction.

5.The reaction with water and dye takes place in a smaller extent.

6.The strength of covalent bond formed between cellulose polymer and reactive group is more than hydrogen bonding, vander wall’s force of attraction and metal co-ordination bonds.

7.Extreme acidic and alkaline condition should be avoided, otherwise hydrolysis will take place resulting bond breakage and poor wash fastness.