Scalable single-step synthesis of lignin-based liquid polyols with ethylene carbonate for polyurethane foams

A new method for the synthesis of lignin-based liquid polyols was developed. Organosolv lignin reacted with ethylene carbonate in polyethylene glycol as solvent, leading to a full conversion phenolic OH into primary aliphatic groups. These aromatic are obtained single step, without any purification. Upon modification molar mass, wide range hydroxyl values (IOH) can be covered. The up 30%wt have viscosity suitable direct elaboration polyurethane (PUR) foams. presents significant advantages over oxypropylation, most common producing since it is performed at ambient pressure, toxic chemicals, does not require purification or post treatment, and allows produce tunable properties. Four different were then synthesized rigid PUR foams, substitution 100% standard polyether polyol. developed showed very high reactivity, allowing reduce catalyst content formulation by 75%. Rigid foams prepared 25% polyol properties commercial more than 90% closed cells thermal conductivity about 25 mW m?1/K, perfectly adequate insulation applications.