(327a) Lignin-Based Coating for Superhydrophobic Applications

Lignin is a low-cost bio-renewable resource that could be applied as a sustainable material to alleviate the dependence on oil-based products. Among various applications, lignin-based hydrophobic coating is promising due to the inherent water resistance in plants and the abundant functional groups that could provide possibilities for modification to adjust the hydrophobicity. In the current work, kraft softwood lignin was selected due to its industrial abundance and was modified with oleic acid at the aliphatic hydroxyl groups. The structural change in the modification was characterized by ³¹P NMR and FTIR. The modified lignin was then spray-coated in aqueous solutions on cotton- and nylon-based fabrics, and the water contact angle (WCA) was measured for the coated fabrics. The modified lignin showed an improved WCA compared to raw lignin on both fabrics, showing a near-superhydrophobic performance. This method could be used to prepare fluorocarbon-free coatings with improved hydrophobicity, showing an excellent application perspective.