Reversible Nanocomposites With Carbon Nanotubes as the Diene in the Diels–Alder Reaction

ABSTRACT Carbon nanotubes (CNTs) often require surface functionalization to facilitate uniform distribution and address issues related to aggregation. Due to the sp 2 hybridized carbon atoms on their surface, CNTs readily participate in the Diels–Alder (DA) cycloaddition, allowing covalent modification with various functional groups without any prior pretreatments. This approach offers a straightforward and efficient method for modifying CNT surfaces, enabling tailored functionalization for applications in advanced nanocomposites. Although CNTs have been studied extensively as dienophiles with furan derivatives, their role as dienes, particularly with bismaleimides (BMIs), remains underexplored. This study investigates the functionalization of CNTs using BMIs via the DA reaction. Infrared spectra and thermogravimetric analysis display successful grafting results. Differential scanning calorimetry confirms the covalent linkage between CNTs and BMIs. The BMI‐modified CNTs were combined with furan‐pendant polyketones, forming ternary nanocomposites with improved thermal and mechanical properties. The as‐prepared nanocomposites demonstrate thermal reversibility of five cycles from 50°C to 120°C. This work advances the understanding of CNT functionalization through the DA reaction and provides more possibilities for nanocomposites with strengthened mechanical properties and self‐healing abilities.