Investigation of static and dynamic mechanical properties of graphene-based thermoplastic polyurethane nanocomposites: Experimental and MD simulation approach

Abstract

Abstract

Recent advancements in multiscale analysis are essential for developing high-quality polymer nanocomposites (PNCs) with tailored thermo-mechanical and viscoelastic behaviour. In the current work, a dual approach combining experimental methods and non-equilibrium molecular dynamics (NEMD) simulations enable a thorough evaluation of the material’s performance. This approach provides deeper insights into the influence of graphene (Gr) at the atomic scale and validates these effects at the macroscale. Here, experimental tensile and dynamic mechanical analysis (DMA) testing, paired with NEMD simulations, are used to explore both the static and dynamic mechanical behaviours of Gr-based thermoplastic polyurethane (Gr/TPU) nanocomposites. Tensile and DMA testing results indicate that adding 3 wt % of graphene (Gr) to TPU increases the yield strength by 53.06% and the storage modulus by 17.20%, respectively. Notably, the glass transition temperature (T g ) shifts towards a higher value in the 3 wt% Gr/TPU nanocomposite. Due to weak interfacial interactions and high chain mobility, increasing the Gr content at higher temperatures triggers a decrease in the storage modulus while increasing both the loss tangent and loss modulus. This improvement in the damping factor (tan δ) makes these PNCs promising candidates for applications requiring shock absorption in engineering components.