Polythiosemicarbazones by Condensation of Dithiosemicarbazides and Dialdehydes

An easy access to thermoplastic polythiosemicarbazones (polyTSCs) is presented by condensation of dithiosemicarbazides and aromatic dialdehydes, yielding eight polyTSCs and five co-polyTSCs, exhibiting Mns up to 38 kDa in good yields (58–93%). The polymerization proceeds at room temperature and is typically finished after 2–3 h. The monomer scope was investigated, revealing broad moiety tolerance (aliphatic, cyclic, benzylic, and aromatic groups). Full characterization was performed by proton and carbon NMR spectroscopy, IR spectroscopy, and size exclusion chromatography, confirming the anticipated chemical structure of polyTSCs. Thermal analysis of the polymers showed degradation starting at ∼200 °C by decomposition of the TSC function. Glass transitions were only observed for polymers derived from rigid monomers (162–198 °C). Further versatility of the reaction was underlined by the synthesis of five copolymers using different dithiosemicarbazide monomers.