Azide–Alkyne Click Chemistry and Multifunctional Polymers

“Click Chemistry” is a term that was first used by K. B. Sharpless in 2001 to refer to reactions that have high yield and broad scope, only produce byproducts that can be removed without the use of chromatography, are regio-specific and simple to perform, and can be carried out in solvents that can be removed easily or that are benign. Azide–alkyne cycloaddition, thiol–ene, thiol–yne, and Diels–Alder are leading chemistries belonging to the class of click chemistry. However, the above “click” conditions are also fulfilled by other known reactions, such as nucleophilic ring-opening reactions of epoxides/aziridines, addition to carbon–carbon multiple bonds (oxidative formation of epoxides and Michael additions) and cycloaddition reactions. The so-called “click reactions” are promising for creating polymers with advanced properties, such as shape memory, self-healing ability and other functional/smart polymeric structures. In this chapter, azide–alkyne click reactions and various functional polymers derived through such click chemistry approaches are discussed.