Materials Produced from Plant Biomass. Part III: Degradation Kinetics and Hydrogen Bonding in Lignin

In this study Klason lignins from Eucalyptus grandis (LEUG) and Pinus taeda (LPIT) were characterized using Fourier transform infrared (FTIR) spectroscopy and thermogravimetry (TGA). The degradation kinetic parameters were determined by TGA using the Kissinger method. Thermogravimetric results showed that LPIT had higher thermal stability and also higher activation energy than LEUG. FTIR results showed that the average strength of intermolecular interactions and enthalpy of hydrogen bond formation among the phenolic groups are higher for LPIT than for LEUG. The results demonstrated that differences between thermal stability and degradation mechanisms might be associated with differences in hydrogen bonding in lignin.