Castor oil-based waterborne polyurethane/tunicate cellulose nanocrystals nanocomposites for wearable strain sensors

In this study, tunicate cellulose nanocrystals (TCNCs) were introduced into castor oil-based waterborne polyurethane (WPU) to prepare bio-based nanocomposites through a simple solution blending method. The effect of TCNCs content on the particle size and stability of the composite dispersions, as well as the thermophysical and mechanical properties of the composite films were studied and discussed. The unique structure and properties of TCNCs, such as high crystallinity, large aspect ratio and high modulus, not only greatly improved the storage stability of WPU, but also showed significant reinforcing/toughening effects and excellent compatibility to WPU. By drip-coating silver nanowires (AgNWs) on the surface of the composite films, the flexible strain sensors were fabricated, which showed excellent sensitivity in monitoring human movement.