Two Pathways of Thiolactone Incorporation into Polyurethanes and Their One-Pot Double Postfunctionalization

Thiolactone-functionalized polyurethanes were produced by using a chain extension method. Isocyanate–telechelic urethane prepolymers of different chain lengths were prepared from two different diols and 4,4′-methylenebis(cyclohexyl isocyanate), and then reacted with two different thiolactone-functionalized diols, yielding polyurethanes bearing thiolactone groups either within or along the polymer backbone. Postmodification reactions were performed according to an amine–thiol–thiosulfonate conjugation strategy using various functional amines and thiosulfonates. Different characterization techniques were implemented to prove the double modification, for example, 1H NMR, 19F NMR, SEC, DSC, and fluorometry.