The widespread application of polyurea (PUA) in protective coatings typically requires excellent flame retardancy due to real-world usage scenarios. However, the addition of flame retardant additives often compromises the material’s mechanical properties. In this study, a multifunctional reactive additive, MX-SP-NH2, was creatively prepared by covalently grafting spirocyclic pentaerythritol bisphosphorate disphosphoryl chloride (SPDPC) onto MXene (Ti₃C₂T_x) surfaces, followed by the introduction of 1,3-propanediamine (PDA) by the reaction with SPDPC. MX-SP-NH₂ was then incorporated into PUA, participating in its crosslinking process and significantly enhancing both its mechanical strength and flame retardancy. Compared to the control PUA sample, the micro-crosslinked PUA sample with just 1.0 wt% MX-SP-NH₂ demonstrated a 184.3% increase in tensile strength, a 126.1% increase in elongation at break, and a 436.3% increase in toughness. The flammability characterization revealed that the peak heat release rate, peak smoke production rate, and peak CO production rate were reduced by 31.7%, 28.9%, and 61.5%, respectively, indicating a substantial improvement in fire safety. Additionally, the flame retardant PUA-based flexible strain sensors demonstrated stable electrical signal responsiveness. This work has opened up new potential applications of PUA in flexible electronics.

由于实际使用场景，聚脲（PUA）在保护涂料中的广泛应用通常需要优异的阻燃性。然而，添加阻燃添加剂往往会损害材料的机械性能。在这项研究中，通过将螺环季戊四醇双磷酸酯二磷酰氯（SPDPC）共价接枝到MXene（Ti₃C₂T_x）表面，然后通过与SPDPC的反应引入1,3-丙二胺（PDA），创造性地制备了一种多功能反应性添加剂MX-SP-NH₂。然后将MX-SP-NH₂掺入PUA中，参与其交联过程，显著提高其机械强度和阻燃性。与对照PUA样品相比，仅含1.0 wt%MX-SP-NH₂的微交联PUA样品的拉伸强度提高了184.3%，断裂伸长率提高了126.1%，韧性提高了436.3%。可燃性表征表明，峰值热释放率、峰值烟雾产生率和峰值CO产生率分别降低了31.7%、28.9%和61.5%，表明消防安全得到了实质性改善。此外，基于阻燃PUA的柔性应变传感器表现出稳定的电信号响应性。这项工作开辟了PUA在柔性电子领域的新的潜在应用。