Kinetics and Mechanism of Thermal Degradation of Aldehyde Tanned Leather

作者：Yadi Hu; Jie Liu; Lan Luo; Xiumin Li; Fang Wang; Keyong Tang

来源：Thermochimica Acta, 2020, 178717.

DOI：10.1016/j.tca.2020.178717

• Formaldehyde tanning
• Glutaraldehyde tanning
• Leather
• Thermal degradation kinetics
• TG-FTIR
• Evolved gases

The thermal degradation of hides before and after tanning with formaldehyde and glutaraldehyde were studied using thermogravimetric analyzer (TGA) and TGA coupled with Fourier transform infrared spectrometry (TGA-FTIR). TG-FTIR analysis indicated that the pyrolysis products of both untanned hides and tanned leathers are mainly CO2, NH3, and C = O with some HNCO, CH4 and H2O. Compared to that of untanned hides, the peak intensity of evolved NH3 from formaldehyde tanned one is enhanced, while the evolved temperature decreases from 220 °C to 200 °C. The evolution of C = O is increased due to the introduction of carbonyl groups after formaldehyde tanning. However, for the glutaraldehyde-tanned leather, the evolution peak intensity of C = O decreases with more CO2 yield, suggesting that the carbonyl groups introduced by glutaraldehyde-tanning is mainly changed to CO2 rather than C = O. The kinetic analysis of thermal degradation process of the hides and tanned leathers are also investigated by using the methods of Flynn-Wall-Ozawa, Friedman and Criado. Results indicated that the thermal degradation process can be described by the three-dimensional diffusion model (D3) at the conversion below 0.5. Whereas, at the conversion above 0.5, this process turns to comply random nucleation model (F3).

• 单位
  郑州大学