Effect of Artificial Acid Rain on Aluminium Tanned Leather

This article aims at studying the influence of gaseous pollutants on aluminium tanned leather. Artificial acid rain was used to soak the aluminium tanned collagen materials for 0, 4, 8, 12 and 16 days, then some analytical techniques were used to evaluate the changes of leather during the aging process. Micro hot table (MHT), differential scanning calorimetry (DSC) and thermogravimetry (TG) were used to evaluate the influence of artificial acid rain on thermal behaviors. Scanning electron microscope(SEM) was used to investigate the changes of fibrous morphology during aging process. Fourier transform infrared spectroscopy (FT-IR) was used to investigate the changes of structural property after artificial acid rain treatment. With the extension of aging time, thermal stability and heat resistance were gradually reduced, including shrinkage temperature, thermal denaturing temperature, associated enthalpy, weight loss and temperature for maximum decomposition rate. SEM images showed that the collagen fibers were greatly damaged, the gaps among fibres were disappeared and the fibre bundles were randomly ruptured with the aging time. The FT-IR results showed that, during the aging process, amide A band was moved to higher numbers, amide I and amide II band of collagen were gradually shifted to lower numbers. Consequently, the structure and performance of aluminium tanned leather were damaged by artificial acid rain and the longer the aging time is, the greater the damage is.