VALUE ADDED LEATHER AUXILIARIES FROM PAPER AND PULP INDUSTRY WASTE

The present work involves the preparation of a retanning agent from the organics present in the black liquor generated by paper and pulp industry. Black liquor organics was extracted by using solvent extraction method and subsequently separated as acidic, non-acidic and organic compounds that were not degraded. Acidic and non-acidic organics were sulfonated and further condensed with formaldehyde to obtain a product ideal for application. Sulfonation condensation reactions were modulated to achieve particle size on par with that of commercial syntans. Condensed products from both acidic and non-acidic components were used in lieu of synthetic tanning agents in retanning. The final leathers exhibit off-white color with good mechanical strength as compared to leathers from commercial phenolic syntan. This work reveals that the black liquor, which is a by-product of paper and pulp industry could through an innovative process, be turned into a retanning agent for leather processing. The product has the advantage of being able to replace phenol a product with high market fluctuation.