Self-healing performance of lightweight and electrically conductive ethylene-vinyl acetate copolymer/carbon nanotubes composite foam

Conductive polymer composite foams (CPCFs) featuring light weight and good electrical conductivity have received much attention in a diverse range of applications; however, mechanical damage can seriously affect its electrical conductivity in practical use. Therefore, CPCFs with self-healing ability has aroused much research interest. In this work, an eco-friendly method for preparing ethylene-vinyl acetate copolymer/carbon nanotubes (EVM/CNTs) composite foam using supercritical N-2 as a foaming agent was reported. This strategy could effectively construct the porous cellular foam structure, in which CNTs were evenly distributed on the cell wall and had the effect of heterogeneous nucleation and improving the viscosity of EVM embryo material, which resulted in reduced cell size, increased cell number and thicker cell wall. When 9 phr CNTs were added, the EVM/CNTs foam conductivity was 8.6 x 10(-9) S.m, the density was 0.14 g.cm(-3), and the resilience was 29%. In addition, the conductivity recovery rate of the foam could reach 66.7% with the healing time of 30 h. More intriguingly, the EVM/CNTs foam was able to fully support the circuits of LED lamp and demonstrate excellent self-healing ability. It exhibited that the EVM/CNTs foam with light weight and environmental protection has great practical application value in the field of conductive and self-healing.