One‐pot deprotection and functionalization of polythiol copolymers via six different thiol–X reactions

Abstract

Thiol chemistry is a versatile and powerful tool for the preparation of functional polymers and materials via post‐polymerization modification. However, polythiols are generally difficult to handle since they are prone to gel formation due to oxidative coupling between pendant thiol groups to form disulfide bridges. One‐pot deprotection and functionalization procedures that avoid polythiol manipulation are therefore attractive. In that regard, a methacrylate monomer carrying a xanthate moiety was used to prepare protected polythiol copolymers via concurrent atom transfer radical polymerization/reversible addition–fragmentation chain transfer. One‐pot deprotection and functionalization were carried out via aminolysis with a primary amine and subsequent functionalization without isolating the intermediate polythiols. Functionalization was exemplified with six different thiol–X reactions. Thiol–ene radical addition was not conclusive since it led to partial gelation. However, one‐pot deprotection and functionalization via thiol–halogen nucleophilic substitution, thiol–epoxy ring opening, thiol–isocyanate reaction, thiol–acrylate Michael addition and thiol–disulfide exchange were quantitative and led to well‐defined polymers. © 2013 Society of Chemical Industry