Impact of Supercritical Carbon Dioxide on the Physical and Chemical Properties of Leather

Leather, a versatile material, faces high resource consumption and waste issues in production. This study explores the use of supercritical carbon dioxide (scCO2) as a green solvent for leather impregnation, assessing its impact on the leather’s chemical and physical properties. Furniture and upper shoe leathers were exposed to CO2 pressures between 100 and 250 bar at 40°C. Results show decreasing fat content with increased pressure, which correlates with reduced tensile strength - especially significant in upper shoe leather at 250 bar with a nearly 50% reduction in fat content from 7% to 3.7% and tensile strength from 480 N to 250 N. However, pressure treatment can also enhance tensile strength when fat reduction is low. The highest increase in tensile strength, from 110 N to 180 N, was observed for furniture leather following treatment at 100 bar. In industrial settings with lower CO2 surplus, fat extraction impacts are assumed to be minimal, suggesting significant potential for resource-efficient leather production using scCO2.