Synthesis of poly(vinyl alcohol) having a thiol group at one end and new block copolymers containing poly(vinyl alchohol) as one constitent

Poly(vinyl alcohol) (PVA) and poly(vinyl acetate) having a thiol group at one end were synthesized by free‐radical polymerization of vinyl acetate in presence of thioacetic acid as a chain transfer agent followed by treating with sodium hydroxide/methanol and ammonia, respectively. It was found that block copolymers containing the PVA sequence as one constituent were obtained by the redox‐initiated polymerization of some vinyl monomers, for example, acrylic acid (AA) and acrylamide (AAm), using PVA having a thiol end group as reductant and an oxidant such as potassium bromate and potassium persulfate.