Enhancement of mechanical and self-healing properties of epoxidized natural rubber by polyethyleneimine modified graphene oxide and its conductive sensors application

The modulus of rubber materials can be increased by compositing hard particles, but it is ineffective in significantly improving the stability and extending the service life. Improving mechanical property and service life through particle reinforcement is a challenge. Herein, a self-healing epoxidized natural rubber (ENR) is prepared via composition with polyamine-modified graphene oxide (GP) based on a supramolecular network. The nanoparticle GP as the reinforcing filler and crosslinking agent participated in the formation of supramolecular networks. The modified GP improved the mechanical properties of composited epoxidized natural rubber (ENR@GP) and gave materials with superior self-healing capacity. The frame network constructed by the GP, which is based on multiple hydrogen bonding interactions, significantly enhanced the tensile strength and Young's modulus of ENR by approximately 3.8 and 3.4 times, respectively. Furthermore, the engineered ENR exhibited remarkable self-healing properties, achieving a maximum healing efficiency of up to 90 %. The conductive strain sensors prepared by ENR@GP could accurately detect the different frequency and range motions. This work provides an improvement strategy for the mechanical and self-healing properties of ENR materials through nanoparticle reinforcement.