Study on the Chemical Kinetics of the Degradation of Conventional Vegetable-Tanned Leather in Simulated Acidic Burial Environments

The degradation mechanism of leather is an important research topic in the conservation of leather artifacts, encompassing the effects of physical degradation, chemical degradation, and biodegradation on leather relics. Considering the value of leather artifacts, this study investigated the degradation of vegetable-tanned leather in acidic burial environments. The conventional vegetable tanning method was employed to tan salt-dried hides of sheep, cattle, yak, horse, donkey, and rabbit, which served as substitutes for ancient leather samples. To study the apparent chemical kinetic process and rate of leather degradation, multiple samples were artificially aged in a simulated acidic burial environment and the degradation rates for each leather type were characterized at different aging stages, by measuring changes in puncture strength, The results indicated that the degradation of sheep, cattle, yak, horse, donkey, and rabbit leathers in an acidic environment mainly followed first-order reactions, and the corresponding leather samples exhibited half-lives of 3.2, 3.9, 2.7, 1, 0.7, and 0.7 days, respectively. Therefore, cattle leather exhibited the lowest degradation rate, while rabbitleather exhibited the highest degradation rate under the same aging conditions.