Thermal behaviour and stability of the Arboform® LV3 nature liquid wood

Liquid wood (LW) Arboform® is a novel bio-polymer class of materials consisting in various amounts of lignin, natural fibres, and bio-based additives being a fully biodegradable composite. The full acceptance of LW by industry depends on thermo-mechanical stability as a basic quality condition for engineering applications. The paper aims to investigate the thermal properties and stability of LV3 Nature (LV3) as the uppermost member of Arboform® class of materials under different conditions (i.e. heating rates) both as primary and processed material. The results are discussed in terms of differential scanning calorimetry (DSC) and infrared (IR) spectrometry analysis. DSC thermograms highlight specific changes in corresponding areas and peak positions revealing the polymer behaviour: higher heating rate results in higher activation energies and delays of both endo and exothermic reactions in the temperature range of applications. The FTIR spectra of primary granules and processed LV3 Arboform® show maintaining of the initial functional molecular groups supporting a positive response of the material towards reuse. SEM investigations confirm liaising of the processed composite: no changes at the matrix/fibres interface were found. The results create opportunities in process technologies and applications development of this lignin matrix composite material as a candidate for thermo-plastics polymers.