Catalytic performance of polymer-supported ionic liquids in the synthesis of glycerol carbonate from glycerol and urea

Abstract

Ionic liquids (ILs) immobilized onto a structurally modified Merrifield peptide resin (MPR) were prepared through the reaction of imidazole with alkoxylated MPR. Elemental analysis and scanning electron microscopy (SEM) observations showed that the immobilized IL groups were effectively incorporated on the support. The MPR-supported ILs (MPR-ILs) proved to be effective heterogeneous catalysts for the synthesis of glycerol carbonate (GC) from glycerol and urea. MPR-ILs with longer alkyl chain linkers and fewer sterically hindered counteranions resulted in higher conversion of glycerol. High temperature, high degree of vacuum and the presence of zinc oxide co-catalyst were favorable for glycerol conversion. The MPR-ILs could be reused in up to three consecutive runs without significant loss of their catalytic activity. © 2011 Springer Science+Business Media B.V.