Mechanochemical synthesis of poly(azomethine)s: a sustainable vehicle for metallic supports in valorisation of glycerol

A polymeric support based on a poly(azomethine) (PAM) structure was synthesized using mechanochemical polymerization (PAM@M) and compared with its counterpart prepared via conventional high-temperature solution-phase polycondensation (PAM@T). The mechanochemical approach not only significantly reduced the synthesis time (1 hour versus 24 hours), but also resulted in a polymer with amorphous character while the one synthesized via conventional heating exhibits some crystalline peaks. FePAM@M demonstrated superior catalytic performance with complete conversion of glycerol to solketal with 100% selectivity in only 1 hour at room temperature, exhibiting an impressive environmental factor (E-factor = 3.49). The conversion of glycerol into value-added products is essential due to its large-scale generation as a by-product of biodiesel, so the results of this work highlight FePAM@M as a highly efficient and sustainable catalyst for this valorisation.