Mechanically robust, self-healing and conductive rubber with dual dynamic interactions of hydrogen bonds and borate ester bonds

作者：Zhang, Jiahao; Cao, Liming^*; Chen, Yukun^*

来源：European Polymer Journal, 2022, 168: 111103.

DOI：10.1016/j.eurpolymj.2022.111103

• Self-healing
• Electrical conductivity
• Frame structure
• Hydrogen bonds
• Borate ester bonds

Recently, conductive polymers have attracted attention due to their potential in flexible electronic devices. However, the fragility of the matrixes limits their wide applications. Herein, we designed a rubber-based composite with robust mechanical properties, excellent conductive and self-healing performance. The composite was fabricated by a simple and maneuverable method via emulsion blending of epoxidized natural rubber (ENR), carboxymethyl chitosan (CMCS), dopamine (DA) and multi-walled carbon nanotubes (CNTs). By taking advantage of the synergistic effect between the dynamic reversible hydrogen bonds and borate ester bonds, the composite exhibited efficient self-healing behavior under moderate conditions. What's more, CMCS and CNTs were selectively dispersed in the matrix to construct a frame network structure, which increased the tensile strength to 3.61 MPa, and achieved the maximum conductivity of 6.64 x 10(-2) S/m. Furthermore, based on the stretchability and electrical conductibility, the composite is sensitively capable of capturing the variation of strain, and thus shows great potential in strain sensors.