Influence of different tanning agents on bovine leather thermal degradation

• Published in: Journal of thermal analysis and calorimetry Vol. 134; no. 1; pp. 583 - 594
• Main Authors: Rosu, Liliana, Varganici, Cristian–Dragos, Crudu, Andra–Manuela, Rosu, Dan
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.10.2018; Springer; Springer Nature B.V
• Subjects: Aluminum; Analytical Chemistry; Chemistry; Chemistry and Materials Science; Chromium salts; Comparative analysis; Fourier transforms; Gas analysis; Infrared analysis; Infrared spectrophotometers; Inorganic Chemistry; Leather; Measurement Science and Instrumentation; Morphology; Physical Chemistry; Polymer Sciences; Process parameters; Quadrupoles; Regression analysis; Residues; Tanning; Tanning (Leather finishing); Thermal decomposition; Thermal degradation; Thermal stability; Thermodynamic properties; Thermogravimetry; Titanium; Thermal decomposition kinetics; Chrome-free tanned bovine leather (wet-white); Chromium tanned leather (wet-blue); Residue analysis; Thermogravimetric analysis; Evolved gases analysis
• ISSN: 1388-6150; 1588-2926
• DOI: 10.1007/s10973-018-7076-3

The objective of the paper consists in studying the thermal behavior of chrome-free tanned bovine leather (wet-white), using a new product based on titanium and aluminum salts, compared with the same leather tanned by chromium salts (wet-blue). The aim is to find a possibility for replacing the wet-blue leather, containing Cr (III) salts, with the environmentally friendly wet-white leather. The thermal behavior was studied by dynamic thermogravimetry in nitrogen atmosphere, up to 700 °C. Global kinetic thermal decomposition parameters values were obtained with the isoconversional integral method of Flynn–Wall–Ozawa. The kinetic model best describing the thermal degradation process and the kinetic parameters for each individual stage were determined from non-isothermal data by means of a multivariate nonlinear regression method. The evolved gases analysis was conducted on a coupling to a quadrupole mass spectrometer and a Fourier transform infrared spectrophotometer equipped with external modulus for gas analysis. FTIR, microscopic, and elementary composition studies of residues were conducted. There was found that the differences in non-isothermal decomposition kinetics, evolved gases, and residue analyses were dependent on the nature of the two used tanning agents. It was observed that the wet-white leather exhibited lower thermal stability and temperatures of evolved gases. The metal concentrations in the residues and their porous and fibrillar morphologies recommend them as possible candidates for obtaining cost-friendly adsorbents.