Electro-thermal properties and characterization of the flexible polyurethane-graphene nanocomposite films

The flexible film of polyurethane/graphene (PU/G) composition with the different mass fractions of reduced graphene oxide (rGO) was synthesized by the in situ polymerization method and the electrothermal properties of the films were investigated. Results show by increasing the mass fraction of rGO to 5 wt% (PU/G5), the composition goes to the percolation zone. Further, the PU with 20 wt% of rGO (PU/G20) shows good conductivity which is relatively stable at different voltages (similar to 135 omega/sq). Moreover, using graphene in the PU matrix has increased its thermal stability. PU/Gs stable up to 200 degrees C by assisting graphene. Also, the maximum Seebeck coefficient and voltage of PU/Gs (5, 10, 20) obtain at about 45 degrees C and 85 degrees C respectively, and PU/G20 has better performance than others. In addition, the electrothermal response of PU/G20 shows good repeatability and could reach 75 degrees C and 45 degrees C by applying the 22 V and 12 V respectively. The thermal stability, good electrothermal response, and flexibility of the sample suggest it for electrical heaters and wearable applications.