Engineered Self-Blown Nonisocyanate Polyurethanes with Synchronously Enhanced Electromagnetic Interference Shielding and Dimensional Stability

The growing demand for environmentally friendly materials has driven significant interest in nonisocyanate polyurethane (NIPU) foams. This study presents a facile synthesis of self-blown NIPU foams through a conventional foaming process using binary and ternary cyclic carbonates, enabling the rapid formation of an enhanced polyurethane network within minutes without external nucleating agents. Through strategic incorporation of conductive and magnetic fillers, the modified NIPU foams exhibited exceptional electromagnetic interference (EMI) shielding performance, achieving a shielding effectiveness of 71 dB in the frequency range of 8.2–12.4 GHz. The porous architecture combined with the synergistic effect of functional fillers predominantly facilitated electromagnetic wave absorption, effectively mitigating secondary pollution. Notably, the modified foams demonstrated remarkable improvement in dimensional stability, reducing equilibrium water absorption from 397.5% to 276.7%, and a transition from hydrophilic (58°) to hydrophobic (110°) surface properties, addressing the inherent structural instability caused by hydroxyl groups under ambient conditions. The compressive strength of the foam enhanced from 0.019 to 0.26 MPa at 80% strain. This work not only provides a greener, simpler, and more efficient approach for NIPU production but also establishes a paradigm for designing functional polymeric foams for advanced applications.