Thermoreversible Networks by Diels-Alder Reaction of Cellulose Furoates With Bismaleimides

Remendable materials are synthesized by thermoreversible crosslinking of a cellulosic diene with a flexible bisdienophile by DA reaction. Hydroxyethylcellulose is esterified with both furoyl chloride and acetic anhydride, leading to a processible polymer with pending furane substituents. Crosslinking is achieved by heating with 1,6-bis(N-maleimido)hexane, thus initiating the DA reaction. Heating to higher temperatures gave rise to the back (retro-DA) reaction, thus restituting the reactants. Consequently, temperature cycling triggers subsequent retro-DA and DA reactions that allow self-healing of these materials. The use of cellulose enables the construction of highly oriented specimens with high modulus and tensile strength. The introduction of flexible hexamethylene spacers avoids brittleness of the material.