Highly Conductive Poly(Imide–Imine)Hybrid Vitrimer-Graphene Aerogel Composites

Comprehensive Summary,Although polyimides(PIs)have shown great potential for a broad range of applications,it remains very challenging to achieve the malleability,rehealability and recyclability for PIs and their composites targeting various applications,particularly for the rapidly emerging flexible and stretchable electronics.Herein,malleable conductive poly(imide-imine)hybrid(PIIH)vitrimer-graphene aerogel(GA)composites have been prepared,for the first time,via simple sol-gel film formation followed by heat-press.The resulting PIIH-GA composites exhibit not only the highly desired properties of thermosetting(strong mechanical strength)and thermoplastic(reprocessability)polymers,but also good conductivity enabled by the GA filler.PIIH3-GA-10(with 10 wt%GA)showed one of the highest electrical conductivities(26.7 S/m)for PI-based composites,as well as good electromagnetic interference(EMI)shielding performance.Moreover,the PIIH-GA films could maintain good performance during stretching and even after chemical recycling,which opens new opportunities for flexible and sustainable electronics development.

Monolithic polyimine vitrimer/graphene aerogel composites

Graphene-polymer composites have attracted great attention as sensing materials due to their tailorable electrical conductivity, physicochemical properties, and sensitivity to geometric and functional changes.Herein, we report the first example of cylindrical monolithic polyimine vitrimer/graphene composites with excellent mechanical, compressive, rehealable and recyclable, and piezoresistive properties via simple infiltration of polymer monomers into the pores of graphene aerogel followed by thermal curing. The composites exhibit excellent durable compressibility(negligible reduction in the compression properties even after 3000 consecutive compression cycles), rapid recovery to the original size upon stress released,high compressive strength(up to 1.2 MPa), and high conductivity(up to 79 S/m). Excellent piezoresistive properties were observed, displaying consistent and reliable change of the electrical resistance with the compression ratio. Furthermore, rehealing with ~100% recovery of the compressive strength and electric conductivity was achieved under mild rehealing conditions, which is highly desired but has rarely been reported for electronic materials. The facile strategy for fabrication of rehealable monolithic polymer/GAs can open new possibilities for the sustainable development of composites with high electrical conductivity for various applications such as sensing, health monitoring, and movement detection.