Understanding the thermoplasticization mechanism of wood via esterification with fatty acids: A comparative study of the reactivity of cellulose, hemicelluloses and lignin

Thermoplastic materials can be obtained through solvent free wood esterification with fatty acid using tri-fluoroacetic anhydride (TFAA) as promoter. This study aims to investigate the mechanism of wood thermo-plasticization mechanism by understanding the role of each wood component in esterification. High accessibility for acylation was found in cellulose indicated by the highest weight percent gain (WPG), followed by lignin and hemicelluloses. However, significant chemical structural changes were recorded for each spruce wood compo-nents observed by Fourier-transform infrared spectroscopy (FTIR) and cross-polarization/magic angle spinning solid state nuclear magnetic resonance (CP/MAS 13C NMR), promoting thus the improvement of their thermal properties detected by (thermogravimetric analysis) TGA and (differential scanning calorimeter) DSC. Cellulose as a major component wood played an important role in wood plasticization, indicated by the low softening temperature before degradation recorded by (thermomechanical analysis) TMA. Hemicelluloses presenting lower WPG, showed the same effect as cellulose on thermoplasticization supported by the low softening temperature observed by TMA and (scanning electron microscope) SEM. Acylated lignin did not show thermoplastic prop-erties, but resulted in important hydrophobic aspects of materials.

Automated summary

This study investigates the role of different wood components in esterification and their effects on wood thermo-plasticization. Cellulose is found to play a significant role in wood plasticization, while hemicelluloses also have an effect. Acylated lignin improves the hydrophobic properties of the materials.