Choong, P. S.; Chong, N. X.; Tam, E. K. W.; Seayad, A. M.; Seayad, J.; Jana, S., Biobased nonisocyanate polyurethanes as recyclable and intrinsic self-healing coating with triple healing sites. ACS Macro Letters 2021, 10 (5), 635-641.
Polymer coatings having high amounts of renewable carbon and self-healing properties are highly sought after in a sustainability perspective. We report here the development of bio-/CO2-derived nonisocyanate polyurethane (NIPU) coatings which are recyclable and healable via three different types of healing mechanisms. These NIPUs contain furan rings in their main chain which after cross-linking with bismaleimides form organogels having a thermo-reversible sol–gel transition and solvent-borne coatings with improved properties. Judicial selection of the bismaleimide cross-linker structure enabled us to produce recyclable and intrinsic healable coatings mediated by heat (thermo-healing), moisture (moisture-healing), and, more interestingly, dry conditions at room temperature (self-healing). The intrinsic moisture-healing property of NIPU-based coatings is unprecedented and is mainly due to the presence of hydroxyl functionalities in the NIPU structure. The uniqueness of these cross-linked biobased NIPU as recyclable coatings having triple healing sites present in their structure gives these materials potential for sustainable and functional applications.
This research / project is supported by the Agency for Science, Technology and Research (A*STAR) - Industry Alignment Fund - Pre-Positioning Programme (IAF-PP))
Grant Reference no. : A1786a0027