Characterization of Historical and Modern Leathers Using FTIR, XRD, SEM-EDX, and Thermal Techniques

Abstract

Abstract A comprehensive study was conducted on four aged leather pieces of British origin that were utilized in book binding, dating back to the period between 1832 and 1860. The objective of this study was to characterize the thermal, structural, and deterioration properties of these historical leather fragments. Additionally, this study included two newly acquired leather samples of Indian provenance, proposed as potential replacements for this historical leather. The investigative process employed Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM-EDX). Through the FTIR analysis, distinct spectral shifts were identified in the amide A band, indicating a disruption of hydrogen bonding within the aged leather. XRD diffractograms revealed the presence of amorphous phases in the aged leather specimens, signifying the deterioration of their triple helical structure. Notably, DSC analysis provided insight into the denaturation of the collagen-tannin matrix inherent to the historical leather, underlining the transformative effects of time on this intricate material composition. Under SEM analysis, cracks, fibre deterioration, and a general weakening in structural integrity were observed in the aged leather fragments. The EDX data identified one of the new leather samples as chrome-tanned, while the remaining samples exhibited characteristics consistent with vegetable-tanned leather.