Enhancing surface and functional properties of chrome-tanned leather using natural oils

Natural oils have recently emerged as sustainable alternatives to synthetic fatliquors for improving the performance and environmental profile of leather. In this study, the surface, mechanical, and structural properties of chrome-tanned cattle leather treated with natural oils – juniper, tansy, and almond – were examined to assess their potential as eco-friendly finishing agents. The treated leathers were tested for tensile strength, elongation, flexural resistance, water absorption, water permeability, and shrinkage temperature, while structural changes were characterized by scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR). The results showed that natural oils enhanced the functional performance of leather by improving flexibility, water resistance, and structural uniformity. Almond oil gave the highest elongation and surface softness; juniper oil effectively filled interfibrillar voids and increased compactness, while tansy oil improved tensile strength and smoothness. SEM images confirmed fewer microcracks and better surface uniformity after oil treatment. FTIR spectra demonstrated the integration of oil-derived functional groups into the collagen matrix, indicating interactions responsible for hydrophobicity and stabilization. Overall, natural oil treatment produced smoother, more flexible, and thermally stable leather surfaces, demonstrating a sustainable and effective method for surface finishing and lubrication in leather processing.