Preparation and electrical property evaluation of vapor-grown carbon nanofibers reinforced natural rubber composites

Natural rubber composites with different contents of 1 wt%, 3 wt%, 5 wt%, 10 wt%, and 20 wt% vapor-grown carbon nanofibers were synthesized using a solvent casting method. The morphology, electrical conductivity, dielectric property, and electromagnetic interference shielding effectiveness of natural rubber/vapor-grown carbon nanofiber composites at room temperature were investigated. The scanning electron microscopy image showed there was an even dispersion of vapor-grown carbon nanofibers in natural rubber. The electrical conductivity increased with the increase in vapor-grown carbon nanofiber content. The percolation threshold of natural rubber/vapor-grown carbon nanofiber composites was about 4.9 wt% according to the power law. The dielectric property of natural rubber/vapor-grown carbon nanofiber composites had frequency dependence and increased along with the addition of vapor-grown carbon nanofibers. The electromagnetic interference shielding effectiveness in X-band microwave frequency of natural rubber/20 wt% vapor-grown carbon nanofiber composite with 1 mm thickness was 12.8 dB.