A Novel Approach for the Synthesis of Thermo‐Responsive Co‐Polyesters Incorporating Reversible Diels–Alder Adducts

The proof of concept for a new copolymerization approach taking advantage of the thermally reversible aptitude of the furan/maleimide Diels–Alder (DA) adducts is reported here. A new monomer bearing two carboxylic acids as end‐groups and a Diels–Alder adduct within its structure is synthesized using benign and mild reaction conditions. Two polyesters are then fabricated from the DA‐diacid and 1,6‐hexanediol and 1,4‐benzenedimethanol, respectively, and characterized by 1H‐NMR, GPC, DSC, and TGA. Kinetic studies of these polyesters, performed by 1H‐NMR spectroscopy at variable temperatures, establish the appropriate conditions for their controlled depolymerization, through the retro Diels–Alder reaction (rDA), and their re‐construction through the DA reaction, showing moreover the reproducibility of this rDA/DA cycle. Finally, by exploiting this peculiar feature, a copolyester is successfully synthesized from the concomitant treatment of the two homopolymers, demonstrating the effectiveness of the method. The present approach provides a new method for the fabrication of multicomponent copolymers based on the DA/rDA strategy that is extendable to a variety of other polycondensation materials, such as polyesters, polyamides, polyurethanes, and epoxies, allowing the establishment of a library of novel architectures through this one‐pot approach. A thermo‐responsive copolymerization is developed by exploiting the reversible behavior of furan‐maleimide Diels‐Alder (DA) adducts. A diacid monomer presenting a DA adduct within its structure is polymerized into different polyesters characterized by the presence of a DA adduct into their backbone. Co‐polyesters are finally obtained by treating a mixture of polymers with a simple thermal cycle.