Polyurethane (PU) coatings, synthesized from the polymerization between polyols and isocyanate, are an important category of polymer coating for the protection of metals in harsh conditions. Currently, most polyols used in PU synthesis are derived from petroleum feedstocks. In this study, we produced lignin-based PU (LPU) coatings using enzymatic hydrolysis lignin through the sequential ethanol fractionation, ethylene carbonate (EC) hydroxyethylation, and hexamethylene diisocyanate (HDI) polymerization steps. Ethanol extraction increased lignin’s structure homogeneity, and EC hydroxyethylation increased lignin’s reactivity, both facilitate the preparation of LPU coatings. LPU coating chemicals were coated onto aluminum surfaces and curing them in an oven at moderate temperatures. The chemical structure, morphology, of LPU coatings were characterized using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) respectively. The water wettability of LPU coatings was determined by the water contact angle measurement. Finally, the anti-corrosive performance of the LPU coatings was studied using electrochemical impedance spectroscopy (EIS). The results of this study demonstrate a novel approach for the production of sustainable anti-corrosive PU coatings that may find direct industrial application in the field of corrosion prevention for aluminum surfaces.

Anti-corrosive polyurethane coating from ethanol-fractionated and ethylene carbonate-hydroxyethylated lignin

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.