Synthesis of polymers with an intact lactone ring structure in the main chain

By means of photoinitiated SH-En-polyaddition of 2-ethylidene-6-hepten-5-olide (δ-lactone) and 2,2'-(ethylenedioxy)diethanethiol or 1,3-bis(3-mercaptopropyl)-1,1,3,3-tetramethyldisiloxane, it was possible for the first time to form a high-molecular linear polymer with an intact lactone structure. Under these conditions, the reactivity does not depend on the carbon-carbon double bond structure. With pentaerythritol-tetrakis(3-mercaptopropionate) as a crosslinking agent, networks are formed; the structure of the comonomers and the proportionate composition of the monomers modify the polymer properties. These novel polymers have been fully characterized.