Click chemistry as a promising tool for side-chain functionalization of polyurethanes

Linear polyurethanes (PUs) having alkyne groups located along the backbone have been synthesized by reacting two different alkyne-functionalized diols with a diisocyanate compound. H-1 NMR and FTIR proved the presence of these functional groups and the ability for the introduction of an elevated and controllable amount of functional groups that do not interfere with the PU chemistry. TGA measurements demonstrated that the incorporated alkyne diol in the PU materials strongly improves the final char yield. In the second part of the work, the copper catalyzed Huisgen 1,3-dipolar cycloaddition was undertaken between the alkyne-functionalized PUs and a variety of azide compounds such as benzyl azide and different fluorinated azide compounds, resulting in side-chain functionalized PUs with varying degree of functionalization. H-1 NMR spectra clearly indicated the quantitative yields of the "click" reaction.