Polyoxometallate catalyzed oxidative modification of lignin as a favorable pre-treatment for copolymerization with propylene oxide for polyurethanes production

The oxypropylation of the parent and oxidized lignins with propylene oxide (PO) was studied in high pressure Parr reactor using KOH as a catalyst. It was shown that oxypropylation of lignin pre-oxidized in the system POM/H2O2 proceeded in the similar manner as the parent lignin but the rate of the process was some lower due to the presence of higher amount of -COOH groups with lower nucleophilicity