Abstract

Studies on the interactions involved in leather dyeing have been carried out using natural and chemically modified hide powders with five different leather dyes (C.I. Acid Yellow 36, CI. Basic Brown 4, C.L Mordant Violet 5, 1:1 chromium III complex of C.I. Mordant Violet 5 and 1:2 chromium III complex of CI. Mordant Violet 5). Kinetic and thermodynamic aspects such as the rate of dyeing, heat of dyeing, adsorption and affinity of these leather dyes on native and modified hide powders have been studied to obtain indirect evidence regarding the nature of dye-fibre bonds. Heat of dyeing values for most of the dyes studied were found to be less than 10 kcal mol ‘indicating that physical adsorption was mainly responsible for the uptake. The dyed samples of hide powders were subjected to stripping with different solvent systems for additional data to supplement our findings.