Gamma‐Induced CNC Cross‐Linking for Structural Reinforcement of Ti 3 C 2 T x /Polyurethane Nanocomposites

ABSTRACT This study investigates the profound effects of gamma irradiation on the structural, thermal, and mechanical integrity of Ti 3 C 2 T polyurethane (PU) nanocomposite films, which were subjected to escalating doses of 10, 50, and 100 kGy. Structural analysis, confirmed by FTIR spectroscopy and XPS N 1 s deconvolution, provided direct molecular evidence that radiation‐induced cross‐linking successfully tailored the material's performance by systematically reducing NH groups and forming a rigid CNC chemical network within the PU matrix. This structural transformation resulted in a clear dose‐dependent enhancement in thermal stability (TGA) and a significant improvement in mechanical performance, specifically an increase in Young's Modulus and ultimate tensile strength. This confirms the successful transformation of the elastomeric PU into a robust, radiation‐hardened material suitable for demanding structural applications. However, this same cross‐linking mechanism caused a catastrophic three‐order‐of‐magnitude decrease in electrical conductivity ( σ DC ), attributed to the severe disruption of the MXene percolation network. This trade‐off invalidates the material's use for general high‐performance conductive applications but introduces a novel functional consequence: the predictable, dose‐dependent change in electrical resistivity proposes its potential as an irreversible, solid‐state radiation indicator, requiring comprehensive sensor validation for full deployment. These findings establish gamma irradiation as a precise tool for interface engineering and structural reinforcement in PU/MXene systems.