Fractionation of Kraft Lignin for Production of Alkyd Resin for Bio-based Coatings

LIGNICOAT partner VTT, the Technical Research Centre of Finland, presented an oral presentation titled “Fractionation of Kraft Lignin for Production of Alkyd Resin for Bio-based Coatings” at the 2024 AIChE Annual Meeting. The AIChE Annual Meeting occurred in San Diego, California (USA). The presentation focuses on using lignin-based alkyd resins to coat metal surfaces. VTT and BARPIMO researchers explored the potential of using kraft lignin (KL) as a replacement for phthalic anhydride in alkyd resins to increase the bio-content of the material. VTT researchers focused on replacing phthalic anhydride with KL to increase the bio-content of the material. Solvent fractionation was investigated to improve lignin’s solubility and reactivity. This process yielded more uniform, lower molecular weight lignin fractions with higher phenolic OH and COOH group content. These fractions were then used to develop alkyd resins and coatings that showed promising performance compared to commercial standards. The presentation also addressed the issue of odor and volatile organic compound (VOC) release associated with low molecular weight KL. VTT and BARPIMO identified potential strategies to reduce these emissions.