Preparation and Properties of Waterborne Polyurethane/Carbon Nanotube/Graphene/Cellulose Nanofiber Composites

With the rapid advancement of the flexible electronics industry, there is an urgent need to enhance the mechanical properties and thermal stability of flexible electronic devices to expand their range of applications. To address this need, flexible conductive composites have been developed using waterborne polyurethane (WPU) as the matrix, carbon nanotubes (CNTs) and graphene (GA) as conductive fillers, and incorporating cellulose nanofibers (CNFs). The carbon fillers create a conductive and thermal conductivity network within the matrix, while the presence of CNFs improves the dispersion of CNTs and GA, thereby enhancing the overall network structure. The resulting WGNF composites exhibit a resistivity of up to 1.05 × 104 Ω·cm, a tensile strength of 26.74 MPa, and a thermal conductivity of 0.494 W/(m·K). This demonstrates that incorporating cellulose offers an effective solution for producing high-performance polymeric conductive and thermally conductive composites, showing promising potential for flexible wearable devices.