Click-ligation of coumarin to polyether polyols for polyurethane foams

A simple strategy for the synthesis and functionalization of polyurethanes is described. Anionic ring-opening polymerization was combined with click' chemistry to synthesize polyols with fluorescent properties. This route allows the incorporation of a wide range of functionalities in the polyols with an easy, clean and highly selective process compatible with several types of functional groups. The proposed strategy opens the way to the production, in a cost-effective way, of smart' polyurethanes with non-conventional properties like fire retardancy, antimite properties, antibacterial properties, etc. Alkynyl groups were introduced into the polyol chains by the controlled addition of glycidyl propargyl ether as co-monomer during a conventional anionic ring-opening copolymerization with propylene oxide. Subsequently 4-azidomethyl-7-methoxycoumarin molecules were introduced onto the alkynyl-polyether polyols by copper-catalysed cycloaddition reactions to produce end-functionalized polyols. The chemical structure of the novel polyols was characterized using infrared spectroscopy, nuclear magnetic resonance spectroscopy, gel permeation chromatography with triple detection and matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy. These characterization techniques confirmed the presence of a considerable amount of functional groups in the structure of the polyols. Finally, various fluorescent rigid foams, based on the functionalized polyols, were synthesized. Copyright (c) 2012 Society of Chemical Industry