Development of recoverable and recyclable Fe3O4-supported organocatalysts for ring-opening polymerization

An iminotris(dimethylamino)phosphorane (HMP 1 ) phosphazene superbase has been anchored onto poly(hexachlorocyclotriphosphazene- co -4,4′-sulfonyldiphenol) (PZS)-coated Fe 3 O 4 magnetic nanoparticles (MNPs) through efficient phosphorous-chloride (from PZS surface) and imino (from HMP 1 ) reaction. Subsequently, these novel heterogeneous Fe 3 O 4 @PZS@HMP 1 catalysts have been successfully utilized in the ring-opening polymerization of ε -caprolactone ( ε -CL) and δ -valerolactone ( δ -VL). Notably, such catalysts can be easily removed from the reaction mixture and reused 3 times without obvious activity loss. Graphical Phosphazene superbase was anchored onto poly(hexachlorocyclotriphosphazene- co -4,4′-sulfonyldiphenol) (PZS)-coated Fe 3 O 4 nanoparticles as immobilized catalyst for ring-opening polymerization and its catalytic activity, recoverability and recyclability was investigated.