Toward a Green Polymerization of Lignin‐Derived Monomers in Ethyl Lactate Solution or Aqueous Emulsion

ABSTRACT Novel biobased polymers based on lignin building blocks are synthesized and systematically characterized. The three prominent aromatic aldehydes that can be obtained from oxidative degradation of lignin, namely p‐hydroxybenzaldehyde (H), vanillin (V), and syringaldehyde (S), are chemically modified into radically polymerizable styrenic monomers presenting either a methoxy or butoxy (‐OBu) group at the para‐position. The transformation of these molecules is accomplished and optimized individually on each compound. Subsequently, polymers are successfully prepared by free radical polymerization in homogeneous conditions (in solution using ethyl lactate as green solvent) and in heterogeneous conditions (in aqueous emulsion using a biosourced surfactant). Novel polymeric materials with high thermal stability and a glass transition temperature (Tg) tunable between 40°C and 110°C are obtained, depending on the monomer used.