Urethane polythioether self-crosslinking resins

A straightforward methodology for the synthesis of polythioether resins and resulting coatings was elaborated. The resins were produced via radical stepwise polyaddition of functional bisalkene and bisthiol monomers to yield self-crosslinkable polythioethers, which can be formulated as one-component systems. The thermal curing of these self-crosslinking resins is enabled by the presence of both hydroxyl and blocked isocyanate moieties, thereby resulting in the formation of a urethane polythioether network. Furthermore, the presence of the thioether functions offered the opportunity to alter thermal and mechanical properties by oxidation into sulfoxide or sulfone linkages, resulting in polysulfoxide and -sulfone containing coatings. Thiol-ene chemistry in combination with blocked isocyanate chemistry provides a new platform for functional urethane- and sulfide-containing coatings, which can be tailored to a wide variety of applications.