Bio-based self-healing coatings based on thermo-reversible Diels-Alder reaction

Stimulated by the growing demand for greener and more sustainable polymer systems we have studied thermoreversible polymer networks composed largely (> 83% w/w) of diethylitaconate of bio-based origin. A series of coating materials has been synthesized consisting of linear chains of diethylitaconate copolymerized with furfurylmethacrylate moieties enabling the formation of reversible crosslinks between the chains through the Diels-Alder reaction upon addition of a bismaleimide. The ability to reversibly crosslink these materials can be used to improve the sustainability of the coatings by elongation of the lifetime through enhancement of mechanical properties (glass transition temperature, hardness and susceptibility towards abrasive wear as well as solvent resistance have been quantified). The thermoreversibility of the network makes this kind of crosslinked coatings mendable after a damaging event during the coating life-time and ultimately recyclable. Heat induced decrosslinking of the coating materials through the retro-Diels Alder reaction has been analyzed with differential scanning calorimetry and self-healing has been demonstrated.