Synthesis, characterization and catalytic application of functionalized polyureas

Polyureas are an emerging class of materials which have broad potential applications because of their versatility, complex internal structures. Here polyureas are prepared by the reaction of hexamethylene diisocyanate with either aliphatic or aromatic diamines. Multiple characterization techniques revealed that polyurea materials are porous in nature and stable up to 250 ℃. Further, CP TOSS (Cross Polarized Total Sideband Suppression) 13 C solid state NMR revealed the formation of polyurea. PXRD showed that some polyureas were crystalline and formed a network structure through hydrogen bonds which served as a cross linker. Their highly insoluble nature in polar and non-polar solvents, layered structure makes them apt heterogeneous catalysts. A higher catalytic performance was detected in Knoevenagel condensation reaction between aromatic aldehyde and malononitrile in the presence of polyurea. A decrease in the catalytic activity was detected in the 7 th recycle tentatively due to the adsorption of water molecule.