High-performance anionic waterborne polyurethane/Ag nanocomposites with excellent antibacterial property via in situ synthesis of Ag nanoparticles

Abstract

Anionic waterborne polyurethane (WPU)/inorganic nanoparticle composites have attracted growing interest due to their outstanding properties. In our work, high-performance anionic WPU/Ag nanocomposites with excellent antibacterial property were successfully prepared by an in situ method, where carboxylate-functionalized WPUs served as stabilizers for the synthesis of AgNPs. The chemical structure of the prepared WPU and WPU/Ag nanocomposite was characterized via FTIR spectroscopy and UV-vis spectroscopy, while TEM, SEM and XRD were also used to confirm the formation of AgNPs in the WPU matrix. The results demonstrated that the formed AgNPs exhibited a spherical shape and were evenly distributed in the WPU matrix. The size of AgNPs ranged from 5 to 50 nm depending on the amount of added AgNO₃ in WPU dispersions. More importantly, incorporation of AgNPs in the WPU matrix was demonstrated to significantly improve the thermal stability, mechanical performance and water resistance property of the WPU films. Furthermore, the presence of AgNPs provided the nanocomposite films with excellent antibacterial behavior against E. coli. Given these advantages, our obtained WPU/Ag nanocomposites could be suitable for a broad range of commercial applications.