High-performance castor oil-based polyurethane thermosets: Facile synthesis and properties

With the growing concern on the shortage of fossil resources and the environmental problems associated with their use, vegetable oils as renewable resources are important alternatives to fossil resources. Here, we used castor oil to synthesize 1-thioglycerol modified castor oil polyol with ultra-high hydroxyl value up to 463 mg KOH g−1 via a solvent-free thiol-olefin click reaction. The cross-linked polyurethanes were prepared from this polyol in a solvent-free and catalyst-free manner, and exhibited high tensile strength of ∼83 MPa and Tg of ∼124 °C, much higher than other reported vegetable oil-based polyurethanes. Besides, the obtained polyurethanes exhibited excellent coating and optical properties, much better than the polyurethane from the unmodified castor oil. This work provides a green and high-efficient method of synthesizing vegetable oil-based polyol with ultra-high hydroxyl value to construct high-performance polyurethanes, which will expand the application of vegetable oil-based polymers.