Multifunctional segmented thermoplastic polyurethane nanocomposites reinforced with graphene-based two-dimensional nanofillers in special reference to gas barrier and electrical properties

Abstract This study focuses on the evaluation of the mechanical, thermal, gas barrier, and electrical properties of segmented polyester-based TPU coatings with a low loading of 2D- graphene nanofillers, namely graphene oxide (GO), reduced graphene oxide (RGO), and graphene nanoplatelets (GNP), respectively. TPUs have a unique segmented structure featuring soft and hard segment alternation, which contributes to their inherent tailor-made flexibility and strength. Incorporation of the graphene fillers enhanced the thermal stability, mechanical performance, and electrical conductivity by virtue of their large surface area. TPU at 0.5 wt% GO displayed a tensile strength of 30.4 MPa and 800% elongation at break while preserving flexibility. GO and RGO decreased oxygen permeability by approximately 70% and 46%, respectively. RGO exhibited enhanced mechanical and electrical properties attributed to reduced oxygen content and increased π–π interactions. At 1.0 wt%, GNP established a percolated conductive network exhibiting an electrical conductivity of approximately 9.0 × 10 − 5 S/m, which is 66% greater than that of RGO filled composites. The various oxidation levels and morphologies of these fillers provide unique benefits, facilitating multifunctional TPU nanocomposites. This study clarifies the interactions between graphene and TPU, contributing to applications such as flexible electronics, packaging, protective coatings, and lighter-than-air vehicles.