Unraveling the mechanism of thermal and thermo-oxidative degradation of tannic acid

• The thermal degradation mechanism of tannic acid has been investigated.
• Py–GC–MS and TGA–FTIR are used to examine the products of degradation in gas phase.
• The char study of tannic acid at various temperatures was carried with ATR–FTIR.
• A mechanistic pathway for thermal degradation of tannic acid has been proposed.

The thermal and thermo-oxidative degradation of hydrolysable tannin, i.e. tannic acid is reported. The study on thermal and thermo-oxidative degradation mechanism of tannic acid was carried out by using several advanced thermal characterization techniques such as Thermogravimetric analysis (TGA) coupled with Fourier-Transform Infrared (FTIR) Spectroscopy (TGA–FTIR), pyrolysis–gas chromatography–mass spectroscopy (Py–GC–MS) and Attenuated Total Reflectance (ATR)–FTIR. The condensed phase and gaseous phase degradation studies were combined to deduce a probable degradation pathway for tannic acid molecule at high temperature under nitrogen and air atmosphere.