MXene-Reinforced Self-Blown Non-Isocyanate Polyurethane Foams with Enhanced Thermal and Mechanical Performance

Nonisocyanate polyurethane (NIPU) foams provide a sustainable alternative to conventional isocyanate-based systems but remain limited by low mechanical strength and thermal conductivity. Here, Ti3C2Tx MXene nanosheets were incorporated into self-blown hybrid NIPU foams synthesized from epoxy–cyclic carbonate precursors via amine-induced polymerization with in situ CO2 foaming. Systematic variation of MXene loading (1–7 wt %) revealed strong correlations between nanosheet dispersion, cellular morphology, and multifunctional performance. The MXene fillers refined the foam microstructure, by reducing pore size and thickening cell walls, while simultaneously enhancing polymer chain mobility restriction and interfacial heat transport. These effects yielded substantial increases in glass transition temperature, storage modulus, thermal stability, and thermal conductivity. The results demonstrate that MXene nanosheets act as both reinforcing and structural-modifying agents, enabling sustainable polymer foams with tunable thermomechanical and heat-transfer properties. The developed MXene–NIPU foams combine sustainability with high performance, making them suitable for thermal insulation, packaging, and electronic applications.