Click Chemistry Engineered Hyperbranched Polyurethane–Urea for Functional Coating Applications

This article reports a facile route for the synthesis of different generations of 1,2,3-triazole-rich hyperbranched polyether polyols using click chemistry and extends their application for the development of moisture-cured polyurethane–urea coatings. Initially, three generations of chlorinated hyperbranched polyether polyols were synthesized by ring-opening polymerization of epichlorohydrin with trimethylolpropane in different mole ratios. These chlorinated polyols on continuous treatments with sodium azide and propargyl alcohol result in three generations of 1,2,3-triazole-rich hyperbranched polyether polyols. Furthermore, these different generations of polyols were reacted with 1-iso­cyanato-4-[(4-iso­cyanato­cyclo­hexyl) methyl] cyclohexane (H12MDI) at OH:NCO ratio of 1:1.2 to obtain −NCO-terminated triazole-rich hyperbranched polyurethanes, which were subjected to curing under atmospheric moisture to obtain hyperbranched polyurethane–urea coatings. The coatings showed considerable enhancement in thermal stability, glass transition temperature, and corrosion resistance properties with an increase in generation number. All three generations of coating films show excellent resistance toward various bacterial and fungal attacks.