• Vanbroekhoven, Karolien
• Kouris, Panos D.
• Servaes, Kelly
• Falireas, Panagiotis
• Wroblewska, Aleksandra
• Jedrzejczyk, Monika A.
• Vendamme, R.
• Boot, Michael D.
• Hensen, Emiel, J. M.

Abstract

To render biorefineries economically viable, it is<br/>important to maximize the value of all of the processed<br/>lignocellulosic biomass. However, the hemicellulose fraction is<br/>often overlooked in current biorefinery strategies. In this study, we<br/>demonstrate the valorization of lignin and sugars, both obtained<br/>through dilute acid solvolysis of lignocellulosic biomass, for the<br/>production of lignin/sugar-based polyurethane (LSPU) films as<br/>partial substitutes for petroleum-derived polyols. LSPU films were<br/>prepared using a four-component system, comprising lignin,<br/>hemicellulose-derived sugars, polytetrahydrofuran, and hexamethylene diisocyanate isocyanurate trimer. Our study involved<br/>optimizing the sugar content in the LSPU film formulations to<br/>investigate how the presence of sugar impacts the films’ structural,<br/>thermal, and mechanical properties. The results showed that as the concentration of sugar increased, the mechanical properties of<br/>the LSPU films were improved in comparison to those of sugar-free samples. Additionally, the LSPUs were evaluated as PU<br/>adhesives, where the mechanical properties of the bonded joints, comprising wood substrates, were measured using single-lap shear<br/>tests. The shear strength values obtained were comparable to or even higher than those of a commercial PU glue. Our findings<br/>demonstrate the potential of incorporating hemicellulose-derived sugars in LSPUs for improved mechanical and adhesion properties,<br/>offering new possibilities for the valorization of lignocellulosic derivatives.

Topics

• impedance spectroscopy
• strength
• lignin
• wood