Thia-Michael Reaction for a Thermostable Itaconic-Based Monomer and the Synthesis of Functionalized Biopolyesters

A new building block, derived from dimethyl itaconate, has been synthesized through thia-Michael addition reaction and then exploited for the synthesis of a series of novel aliphatic polyesters. The new monomer, the dimethyl 2-((octylthio)methyl)succinate, demonstrated a remarkable stability toward common conditions of polycondensation (high temperatures and metal-based catalysts) and was suitable for polycondensation reactions with different diols. The resulting polyesters are characterized by high molecular weights and good stability; they are amorphous polymers with a tunable glass transition temperature depending on the rigidity of the diol. The synthetic approach presented here allows, for the first time, remarkably stable polymeric structures based on itaconic acid, circumventing its inherent thermal lability, to be achieved. Furthermore, by demonstration of the successful exploitation of thia-Michael adducts in polymer science, the bases have been set for the creation of a novel renewable platform based on dimethyl itaconate.