Dynamic covalent polymer network enabled bio-based vitrimers with excellent substrate bonding

In this article, we report the synthesis of dynamic covalent polymer network (DCPN)-enabled vitrimers derived from gum rosin-a pine tree extract. The concept of Diels Alder (DA) thermo-reversibility has been used to introduce self-healing/dynamic covalent ability into the polymer systems. For this purpose, the diene moieties were incorporated in the gum rosin-based polymer network, and the bismaleimides served as the dienophiles. The thermo-reversible crosslinks formed between the diene and dienophile moieties can enhance the service life of the materials by improving the durability, mechanical as well as chemical properties of the materials. Upon damage, the thermo-reversible DA bonds de-crosslink resulting in smaller chain segments, enabling the material to flow to the site of damage and seal the fractured edges. The formation of DA crosslinks has been confirmed by using Fourier transform-infrared spectroscopic technique. Scanning electron microscopy analysis was used to verify the self-healing ability of the resin matrix. The healing process was studied after manual scratches were made. The polymers' ability to heal multiple times is investigated using differential scanning calorimetry. The adhesion strength of the self-healing material has been examined on variety of substrates such as glass, steel, and concrete. The materials exhibited superior adhesion strength on glass substrate.