Tough, transparent and antibacterial WPU
To reach a more sustainable society, it is an irresistible trend to replace the solvent-based polyurethane with waterborne polyurethane (WPU). However, it remains a challenge to fabricate WPU materials with excellent mechanical properties. Now, a transparent WPU with strength of 30.1 MPa and toughness of 195.7 MJ/m3 is developed by incorporating hydantoin diol (HD) into WPU macromolecule. The polar segments of WPU interact with each other by H-bonds and agglomerate together to form hard phase, which disperse in soft polycaprolactone diol (PCL) phase, forming micro-phase separated domains. It significantly enhances the tensile strength and toughness of the WPU.
Outstanding antibacterial properties
In comparison with covalent bonds, the reversibility of dynamic physical interactions of H-bonds enables the materials to be healed by heating. In addition, the 3 h-healed HDPU2 film exhibits high toughness (166.9 MJ/m3), tensile strength (20.6 MPa) and strain (2195 %). Furthermore, the HDPU2 film presents outstanding antibacterial properties after chlorination, inactivating 100 % of S. aureus and 96.2 % of E. coli within 60 min.
The study has been published in Progress in Organic Coatings,Volume 172, November 2022.