Structurally diverse polymers from norbornene and thiolactone containing building blocks

A wide set of norbornene-derived polymers with a diversity in backbone and side chain structures has been prepared based on norbornene building blocks that also include a thiolactone group. For this purpose, two thiolactone monomers with differently substituted norbornene moieties were synthesized and their reactivity compared using three different polymerization strategies. First, their potential for amine-thiol-ene polymerization was evaluated using different amines, solvents and initiator concentrations in order to screen their influence on the molecular weight and glass transition temperature. Free radical (co-)polymerization and ring-opening metathesis polymerization were also applied and the obtained polymers were submitted to post-polymerization modification. The results showed that only the monomer 5-norbornenemethyl thiolactone carbamate results in polymer formation under the tested conditions. The obtained compounds were characterized by SEC, TGA, DSC and NMR.