TiO₂ nano-filler and ionic liquid-blended polyurethane elastomer films for enhanced antistatic applications

In the current study, polyurethane (PU) blended with TiO₂ nano-filler and ionic liquid (IL) casted as films by solvent casting method is explored for antistatic applications. The crystalline structure of the obtained PU-films was confirmed by XRD analysis with amorphous broad peak at 2θ≈ 20°, while SEM analysis indicated the nanorod shape of TiO₂ in the TiO₂-blended PU-film surface and porous morphology was observed for IL-blended films. In case of pristine PU-film, the tensile strength (6.1 MPa) and toughness (365.7 mJ/mm³) with no elongation break (until≈ 80% max strain) were observed, while the addition of both TiO₂ and IL had lowered the tensile strength (2.5 ± 0.5 MPa), but still maintained a reasonable toughness (79–163 mJ/mm³) of both the blended PU-films. All the PU-films were thermally stable up to maximum temperature of 473 °C. The surface resistivity values (ρ_s) were highest for the pure PU-film (5.52 \(\times\) $\times$ 10⁸ Ω/sq.) and at low concentration (2 wt%) of filler/IL, but reduced to almost half of the original values at higher amount (4 wt%) loading of both TiO₂ (ρ_s ≈ 3.25 \(\times\) $\times$ 10⁸ Ω/sq.) and IL (ρ_s ≈ 2.66 \(\times\) $\times$ 10⁸ Ω/sq.) in the blended films, attributed to the critical concentration within percolation threshold range. Hence, these blended PU-films with appropriate amount of filler and IL (≥ 4 wt%) could be promising durable materials for preventing build-up of static charges in the electronic and packaging industries.