Enhancing the performance of recyclable polyurea through coordination of rigid chain segments and graphene platelets

In response to the global focus on environmental preservation and sustainable practices, developing nanocomposites featuring recyclable and healing properties is indispensable for high-performance and long-life structures. This study presents a facile approach to develop a recyclable and thermally-induced healing polyurea (PU)/graphene platelet (GNP) nanocomposites with high mechanical properties. A straightforward synthesis method was employed using isophorone diamine (IPDA) as chain extender with rigid cyclic structure. GNPs were modified with IPDA before adding into PU, showing remarkable enhancements in mechanical performance. At 0.10 wt.% GNPs, PU nanocomposites exhibited the maximum mechanical properties, with modified GNPs (M-GNPs) significantly outperforming pristine GNPs. Specifically, the tensile strength of PU increased by 41.3 % with M-GNPs, compared to only 12 % with pristine GNPs, underscoring the critical role of modifying the reinforcing phase. Furthermore, the nanocomposites demonstrated outstanding healing capabilities, achieving 89 % healing efficiency after 24 h at 120 °C. In addition, PU/M-GNP nanocomposites showed exceptional resistance to acidic and alkaline environments in comparison to neat PU. The study not only exemplifies developing high-strength and environmentally friendly materials but also holds promise for diverse applications, including aerospace, vibration damping, and protective coatings.