The Cu(I)-mediated azide–alkyne cycloadditions as a facile and efficient route for functionalization of waterborne polyurethane

The Cu(I)-mediated azide–alkyne cycloaddition reaction, “click” chemistry, has been used to functionalize the waterborne polyurethane, by which a novel fluorinated waterborne polyurethane (FWPU) was synthesized. FWPU was confirmed by FT-IR and ¹H NMR. The structure and properties of FWPU were characterized by water contact angle, water absorption, surface energy, scanning electron microscope (SEM) equipped with energy dispersive X-ray spectrometry (EDS), thermogravimetric analysis (TGA) and X-ray diffraction (XRD), etc. From the research of the surface properties, it was found that the modified materials were endowed with a remarkable hydrophobicity and stain resistance. SEM results showed that the micro-phase separation of FWPU became increasingly apparent with the rise of fluorinated side chains in polyurethane backbone. XRD measurements reflected that the crystallinity of FWPU tended to decrease firstly and then increase with the change of fluorine content. TGA results demonstrated that FWPU possessed flame retardant performance to a certain extent due to the incorporated alkyne groups in the FWPU to improve the final char strongly.