Cyclic carbonate: A green multifunctional agent for sustainable leather manufacture

Abstract

“Go Green” manoeuvre is gaining prominence due to environmental sustainability, where chemical consumption needs to be subjugated. In order to alleviate this issue, industries have adopted the use of multifunctional chemicals as an alternative to mono-functional agents. The global interest in cyclic carbonate is emerging because of its solvent-cum-reagent characteristic. In this work, we have attempted to use “Propylene Carbonate (PC)” as a green multifunctional agent in the different unit processes of leather making. The antimicrobial activity of PC against gram-negative (Bacillus subtilis, Staphylococcus aureus), gram-positive (Escherichia coli, Klebsiella pneumonia) bacterial strains, and mixed culture prepared from putrefied skin extract enables to use of PC in the preservation process as an alternative to common salt (NaCl). The goatskins treated with 15% PC can be stored for up to 2 months without any putrefaction. Further, the developed method reduces the 85% of TDS load from the soaking process and also completely eliminates the generation of contaminated salt. Spectroscopic investigation and molecular dynamic simulation studies clearly indicate that the structural stability of collagen is not affected in the presence of PC. However, it inhibits the activity of collagenase on collagen. The use of PC as an alkali neutralizing agent in the deliming process completely avoids the generation of toxic ammonium gas. The possibility of using PC as an antifungal agent in the chrome tanning process has been attempted. The wet-blue leather treated with 3% PC has been preserved for 30 days without any fungal attack. Hence, the application of PC in various unit processes has a great potential in reducing chemical consumption thereby leading to sustainable leather manufacturing.