Bio-Based Coating Delivers Effective Performance on Wood

Bio-based coating for wood can outperform traditional synthetic options. Global efforts to meet sustainability standards are driving many countries to explore ways to use wood instead of concrete in buildings. For example, France will require all new public buildings starting in 2022 to be constructed from at least 50 percent wood or other sustainable materials. Because wood tends to deteriorate when exposed to sunlight and moisture, protective coatings could help enable wider use of wood. Researchers at Aalto University used lignin, a natural polymer found abundantly in wood and other plant sources, to develop a safe, low-cost, high-performance coating for use in construction. "Our new coating has great potential to protect wood. It is more water-repellent than many commercial coatings because it preserves the wood's natural structure and micro-scale roughness. Because it is hydrophobic, the coating is also highly resistant to staining, and lignin's natural structure resists color changes caused by sunlight. At the same time, it does an excellent job of maintaining the wood's breathability," explains Alexander Henn, a doctoral candidate at the School of Chemical Engineering at Aalto University. Lignin is typically considered a waste product from pulping and biorefinery processes. Approximately 60-120 million tons of lignin are isolated globally each year, with 98 percent of it being burned for energy recovery. Lignin has several beneficial properties; however, the poor solubility of most lignin types and the mediocre performance of lignin-based products have limited their commercial applications so far. As a coating material, lignin is truly very promising compared to currently used synthetic and bio-based coatings, offering excellent corrosion-inhibiting, antibacterial, anti-icing, and UV-protective properties. Monika Österberg, Chair of the Bioproducts and Biosystems Department at Aalto University, says, "Our future research will focus on improving properties such as the coating's flexibility."

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Colloidal Lignin Particles and Epoxies for Bio-Based, Durable, and Multiresistant Nanostructured Coatings https://pubs.acs.org/doi/10.1021/acsami.1c06087 Source / Source: https://www.aalto.fi/en/news/bio-based-coating-for-wood-outperforms-traditional-synthetic-options