Thiol-ene chemistry for polymer coatings and surface modification - building in sustainability and performance

Future advancement of coatings relies on new synthetic building blocks and methods that enable added functionality, while minimising the environmental impact and cost. This review highlights the use of thiol-ene chemistry for surface modification and coatings, a topic of increasing interest in academic and industrial context since the beginning of this century. This chemistry platform has the advantages of rapid and uniform cross-linking, delayed gelation, reduced shrinkage, and insensitivity to oxygen. Recently, it resulted in significant advances in UV-cured coatings, including pigmented acrylate coatings and waterborne polyurethane dispersions. Moreover, biobased coatings were developed via thiol-ene coupling of unsaturated moieties in vegetable oils with multifunctional thiols, resulting in tunable properties. The homogeneous thiol-ene network formation has also been employed in hybrid coatings, yielding synergistic effects of the inorganic components within the thiol-ene matrix. Moreover, the UV-triggered thiol-ene reaction is fast and efficient, which is useful for surface modification with spatial and temporal control. In general, this review will critically describe how thiol-ene chemistry became a powerful tool for the sustainable development of functional coating materials and surfaces with a variety of building blocks.