Reversibly cross-linked fullerene/polyamide composites based on Diels-Alder reaction

Abstract High-performance composites that are mechanically strong and thermally stable are widely used in many fields, introducing additional functionalities into these composites accompanied with improved physical properties can further expand their applications. In this paper, reversibly cross-linked composites consisted of aromatic polyamide (fPA) with pendent furan groups and fullerene C60 was fabricated. The Diels-Alder (D-A) reaction between furan groups and C60 allowed the cross-linking of fPA at moderate temperature, and the cross-linking effect greatly improved the mechanical and thermal properties of composites at a small loading (0.3 wt%) of C60. The retro D-A reaction permitted the dissociation and reprocessing of cross-linked C60/fPA composites at high temperature. Tensile test revealed the similar mechanical properties of reprocessed composites in comparison to their original samples, confirming the good recyclability of C60/fPA composites. Moreover, the improved high-temperature shape memory property of C60/fPA composites as compared to neat fPA was also demonstrated. These fascinating features as well as the easy processing of our C60/fPA composites make them promising materials for various applications.