Waterborne polyurethane with good mechanical properties
Researchers have synthesised a a bio-based waterborne polyurethane with high toughness, superior wear resistance, and water resistance enabled by sorbitol monooleate.
Waterborne polyurethanes (WPUs) often suffer from poor mechanical properties and inferior water resistance. In a new work, dehydrated sorbitan monooleate (SP), a bio-derived renewable polyol, was introduced into the waterborne polyurethane skeleton to modulate the contents of the traditional trifunctional polyol of trimethylolpropane (TMP). Due to the rigid furan ring and the fatty side chain in the SP, the SP-modulated waterborne polyurethanes (WPU-SP) exhibit simultaneous excellent mechanical properties, high toughness, flexibility, and versatility, with the maximum tensile strength of WPU-SP reaching 39.19 MPa, and the film is capable of lifting weights over 25,000 times its own weight without fracture.
Excellent performance in anticorrosion
Additionally, compared to the traditional waterborne polyurethane extended with TMP, the wear resistance and the water resistance of WPU-SP are significantly improved, as the decreases in wear rate and water absorption rate of WPU-SP are up to 59 % and 45 %, respectively. Benefiting from these unique properties, the WPU-SP shows excellent performance in anticorrosion and exceptional applicability for soft leather materials, in which the corrosion prevention efficiency can reach over 95 % and the wear index can be reduced to within 10 mg as a protective coating.
The study has been published in Progress in Organic Coatings, Volume 185, December 2023.
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