Thermo-driven self-healable organic/inorganic nanohybrid polyurethane film with excellent mechanical properties

Waterborne polyurethane (WPU) is widely applied in many fields; however, it is limited by its drawback of low mechanical strength and short lifespan. Polymer nanocomposites have been developed for many years to enhance the mechanical behavior of materials. Nevertheless, obtaining nanofillers with even dispersion to obtain improved mechanical performance is difficult. To solve the above problems, silica nanoparticles modified by furfuryl (furan@SiO2) were synthesized according to the sol–gel process. By introducing furan@SiO2 into a maleimide-terminated waterborne polyurethane matrix, a self-healing system was constructed through a DA/retro-DA process among furan groups and maleimide-terminated waterborne polyurethane, and a series of WPU films with different furan@SiO2 (WMPUS-x) contents were prepared. The structure of furan@SiO2 was clearly corroborated by TEM, SEM, FTIR, etc. Moreover, confirmed by tensile tests, the mechanical properties of all WPU samples were significantly improved due to the addition of rigid furan@SiO2, and their first self-healing efficiencies were all higher than 88%. In this article, a series of thermo-driven self-healable organic/inorganic nanohybrid polyurethane (WMPUS-x) films were prepared with different addition amount of furfuryl modified silica nanoparticles (furan@SiO2). The self-healable system was constructed via a DA/retro-DA process among furan@SiO2 and maleimide-terminated waterborne polyurethane. The results exhibited the addition of furan@SiO2 enhanced the mechanical behavior of all WPU samples.