Gamma-Induced Hardening of Ti3C2Tx Polyurethane Nanocomposites: Enhanced Structural Stability and Mechanical Performance

This study investigates the profound influence of gamma irradiation on the structural, thermal, and mechanical integrity of Ti ₃ C ₂ Tx 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 1s 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, confirming the successful transformation of the elastomeric PU into a robust, radiation-hardened material suitable for structural applications. However, this same cross-linking mechanism caused a catastrophic three-order-of-magnitude decrease in electrical conductivity, 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 dose-dependent resistivity change proposes its potential as an irreversible, solid-state radiation indicator, though comprehensive sensor validation is required for full deployment. These findings establish gamma irradiation as a precise tool for interface engineering and structural reinforcement in PU/MXene systems.