Electron beam radiation crosslinking of natural rubber filled with silica-graphene blend prepared by latex mixing: dynamic mechanical analysis, volume resistivity, and degradation

The mechanical properties of EB-irradiated natural rubber (NR) composites were improved by a synergistic effect of adding silica ( SiO2) and graphene nanoplatelets (GE) mixture into NR matrix, reported in a previous work. In this study, dynamic mechanical analysis (DMA) was performed, from which volume resistivity and degradation properties were determined. Latex NR compound filled with SiO2/ GE mixture was cured by EB irradiation to form NR composites. SEM images and the EDXS elemental mapping indicated good dispersion of GE and SiO2/ GE in the NR matrix. The DMA showed that the storage moduli of NR composites filled with fillers were higher than that of NR-EB. Using 2.5 phr of fillers, which is below the percolation threshold, volume resistivity properties of all NR composites remained unchanged relative to the pure NR and with varying EB doses in the range of 100-250 kGy. Finally, it was found that adding fillers into NR composites caused a decrease in water absorption of irradiated NR composite at 70 degrees C and a relative humidity of 80%. According to the authors' previous work and the present results, this novel NR composites showed a potential in devices related to high-voltage application requiring electrical insulation with enhanced mechanical properties.

Automated summary

The mechanical properties of electron beam (EB)-irradiated natural rubber (NR) composites were improved by adding a mixture of silica and graphene nanoplatelets (GE) into the NR matrix. Dynamic mechanical analysis (DMA) showed that the storage moduli of the NR composites filled with fillers were higher than that of the untreated NR. Additionally, the addition of fillers decreased the water absorption of the irradiated NR composites at high temperatures and humidity.