Production of reactive lignin mix through catalytic solvolysis of organosolv lignin

Several million tons of phenol formaldehyde (PF) resin is produced each year to be used as adhesive in wood products such as plywood. The substitution of petroleum based phenol with bio-based chemical will lower the carbon footprint of PF resin and for-ward bioeconomy. The high amount of methoxy groups and low amount of reactive sites in lignin makes it a challenging feedstock for phenol formal-dehyde (PF) resin applications.
This research presents a novel use of biphasic 2-methyltetrahydrofuran (2-MTHF) / water mixture as a reaction medium in the presence of sodium for-mate as an in-situ base catalyst for producing a re-active lignin mix with a yield of 73.2 wt % from beech organosolv lignin. Treating the feed lignin at a temperature of 310 °C for one hour produced a re-active lignin mix, rich in monoaromatic phenolic units with enhanced reactivity (e.g. 3-methoxycate-chol).
The yield of monoaromatic phenolic compounds in the obtained reactive lignin mixture was 22 wt %. The gel-permeation chromatography (GPC) analy-sis revealed a molar mass dispersity (Đ) of 3.7 with weight-average molar mass (Mw) of 688 g/mol, which is about one fourth of the molar mass of the initial organosolv lignin (Mw = 2423 g/mol, Đ = 7.2). The reactive lignin mix could be used as a re-placement for phenol in a PF resin providing lignin a higher value than just fuel.