Scaling up lignin-based polyols for PU coatings†

Lignin, a promising sustainable feedstock, has been utilized to produce polyols through a novel anionic ring opening polymerization of oxiranes. This approach overcomes the limitations of lignin's heterogeneity, enabling the synthesis of aliphatic polyols with tailored properties at room temperature and atmospheric pressure. By optimization of reaction conditions, polyols with specific characteristics suited for polyurethane dispersion coatings have been achieved. Notably, the process has been successfully scaled up by a factor of 330, from 15 mL to 5 L reactors, while the desired properties have been maintained. The resulting polyols have been used to partially substitute traditional polyols in polyurethane dispersions, demonstrating their potential in wood coating applications. This breakthrough has paved the way for the large-scale production of lignin-based polyols, offering a more sustainable alternative for the coatings industry.