UV absorption, anticorrosion, and long-term antibacterial performance of vegetable oil based cationic waterborne polyurethanes enabled by amino acids

Acids are traditionally used in the production of environmentally-friendly cationic waterborne polyurethane dispersions. However, the effect of their conjugate bases on the final properties of waterborne polyurethanes has been rarely explored. In this study, the effect of different acids in tailoring the performance of bio-based cationic waterborne polyurethanes has been reported. Polyurethane films ranging from flexible elastomers to tough plastics can be obtained, and their properties can be simply controlled by the selection of the acids. The tunability of the hydrogen bonding strength confers the resulting polyurethane films enhanced multi-function, such as UV absorption, anticorrosion properties, and long-term antibacterial performance. These results represent a significant advancement over traditional techniques, providing a simple strategy to tailor the performance of cationic waterborne polyurethanes, and offering environmentally-friendly amino acid substitutes for commonly used acids, such as acetic acid, HCl, or glycolic acid. The methodology described here eliminates long-standing issues of PUs, such as irritating odor, corrosiveness, and air pollution.