Making polyurethanes (PUs) from castor oil (CO) is severely constrained because they cannot be recycled due to the irreversibly cross-linked structure. In addition, a CO-derived PU shows low strength, poor durability and inadequate utility because of its elevated cross-linking density and its soft backbone. To overcome this, using a solvent-free thiol-olefin click reaction, we initially synthesized castor oil that has been modified to become 1-thioglycerol (TCO), and then we employed this polyol to produce cross-linked polyurethanes designated TCO-NCO (NCO-HDI, HMDI, and IPDI) without adding a catalyst or solvent. They showed substantial tensile strength that was significantly greater than previously highlighted vegetable oil polyurethanes but were not recyclable. Then we developed VTCO, a combination of vanillin and TCO that occurred at an elevated temperature while the solvent and catalyst remained present. Thereafter, VTCO-NCO was employed to achieve sustainable polyurethane covalent adaptable networks (CANs) that seemed to have new reversible acetal bonds. The PUs have a high rate of stress relaxation because their structural cross-linking network is made up of dynamic acetal bonds. This research introduces a simple, ubiquitous approach that can reconcile mechanical robustness, recycling performance, chemical degradation, and an environmentally friendly way to make sustainable PUs.
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