Studies on synthesis of chromium free Tanning agents and multifunctional Polymers for sustainable leather Process

Abstract

newline The greener tanning agents devoid of chromium and toxic precursors have recently evoked considerable interest due to environmental concerns associated with chromium. Post tanning process of leather making involves the usage of a large quantity of auxiliary chemicals to impart functional properties to the leather. The use of less quantity of chemicals, which is multifunctional leads to a reduction in pollution load. Hence, this thesis focuses on synthesizing chromium free tanning agents and multifunctional polymers for a cleaner, greener, and sustainable leather processing. newlineOrganic tanning agents present a huge opportunity for developing tanning agents devoid of metals for sustainable and cleaner leather processing. An ideal tanning agent should be non-toxic, biocompatible, and cost-effective. Synthesis of oxazolidine a heterocyclic derivative, devoid of formaldehyde has been attempted. The synthesized oxazolidine has been characterized using NMR and ESI-Mass spectroscopy. Subsequently, polyallylamine a cationic polymer has been synthesized to enhance the uptake of the post tanning chemicals. Synthesized oxazolidine and tannic acid have been used as a combination tanning process. The thermal stability of the combination process is relatively good. The physical strength characteristics and organoleptic properties of oxazolidine and tannic acid tanned leather are comparable with chrome tanned leather. The BOD/COD ratio of the oxazolidine and tannic acid combination tanning process is higher compared to the conventional chrome tanning process indicating the biodegradable nature of the process.