Lignin modification toward bio-based thermoset resins:Methylolation, epoxidation and carbonation

Lignin was extracted from sugarcane bagasse by alkaline process. It was treated with formaldehyde under alkaline conditions to produce methylolated lignin. The methylolated and the initial lignin were then reacted with epichlorohydrin to prepare the corresponding epoxidized (glycidylated) lignins. The epoxidized lignins epoxy groups were determined by epoxy index testing, and then, they were converted to cyclic carbonates through carbonation using CO2 reaction with oxirane rings. Finally, methylolated, epoxidized and carbonated lignins were characterized by FT-IR spectroscopy.

Keywords:

lignin , hydroxymethylation , glycidylation , carbonation