Electrical Conductivity Of Epoxy Composites Research Articles

Electrical conductivity of epoxy composites with silicon carbide powder filler

Electrical conductivity of epoxy composites with silicon carbide powder filler

New sights in the improvement of fracture toughness and electrical conductivity of epoxy composites through chemical hybridization of carbon nanotubes with CaCO3 derived from waste eggshell

New sights in the improvement of fracture toughness and electrical conductivity of epoxy composites through chemical hybridization of carbon nanotubes with CaCO3 derived from waste eggshell

Effective use of nano-carbons in controlling the electrical conductivity of epoxy composites

Glass fiber reinforced epoxy composites were fabricated using MWCNT and GNP fillers, individually and in combination. The objective of combining the two conductive fillers was to enhance the electrical conductivity of the composites. The DC and AC conductivity measurements were carried out to assess the influence of individual fillers and their combinations on the electrical conductivity. High DC conductivity of 3.1 × 10−3 S/m and AC conductivity of 1.31 × 10−2 S/m at 8 MHz were observed, at 2 wt% of MWCNT and 3 wt% of GNP and the values were significantly reduced below 3 wt% of GNP. The observed increase in electrical conductivity is attributed to low contact resistance (299.85Ω) of fillers, reduced tunneling resistance (5.35 × 109Ω) and tunneling distance (1.65 nm) of the composites. The DC and AC conductivity, contact resistance, tunneling resistance and tunneling distance showed reduced dependence on temperature. The AC conductivity of the hybrid composites follows power law. The cut-off frequency of composites was 200 kHz at 3 wt% of GNP and 2 KHz with reduction in weight percentage of GNP. In composite with 2 wt% of MWCNT and 3 wt% of GNP, validity of the percolation model is established.

Synergistic effects of segregated network by polymethylmethacrylate beads and sintering of copper nanoparticles on thermal and electrical properties of epoxy composites

We present a simple method to improve the thermal and electrical conductivity of epoxy composites via sintering of formic acid-treated Cu nanoparticles (NPs) in the presence of polymethylmethacrylate (PMMA) beads. The surface-treated Cu NPs, epoxy, and PMMA beads were mixed and then sintered under 20 MPa of pressure at 200 °C. The morphology of the Cu NPs and the thermal conductivity, volume resistivity, and thermal stability of the epoxy composites were investigated. The significant improvement of the thermal and electrical conductivity of epoxy composites was attributed to segregation of the Cu NPs between PMMA beads and sintering of neighboring Cu NPs. At 30 wt% of Cu NPs, the thermal conductivity of the epoxy composites was 1.05 W/mK, and the volume resistivity was 5.9 × 1010 Ω cm at a (bead)/(epoxy + bead) ratio of 0.6. The thermal stability of the composites increased with increasing cross-linked PMMA bead content. Low-temperature sintering of formic acid-treated Cu NPs in the presence of PMMA beads affords an innovative way to improve the thermal and electrical conductivity of the composites.

Effect of SiC Particles on the Electrical Conductivity of Epoxy Composites

In this paper, the behavior of the electrical conductivity of epoxy/silicon carbide (SiC) composites as a function of weight fraction and particle size of SiC at room temperature has been investigated. Composite samples were prepared by a mixture composed of the same amount of hardener and resin (5 mg) with different amounts (ranging from 5 mg to 7 mg) of silicon carbide powder with different grain sizes (400 and 800 grit). The conduction current was measured under different applied voltages from 1 to 10 kV (corresponding to applied electrical fields from 0.04 kV/mm to 0.4 kV/mm), and the composites microstructure was characterized by scanning electron microscopy. It was shown that the electrical conductivity of epoxy/SiC composites was found to increase when the weight fraction of SiC was increased and also to increase non-linearly as a function of the electrical field.

Fracture toughness and electrical conductivity of epoxy composites filled with carbon nanotubes and spherical particles

The attainment of both high toughness and superior electrical conductivity of epoxy composites is a crucial requirement in some engineering applications. Herein, we developed a strategy to improve these performances of epoxy by combining the multi-wall carbon nanotubes (MWCNTs) and spherical particles. Two different types of spherical particles i.e. soft submicron-rubber and rigid nano-silica particles were chosen to modify the epoxy/MWCNT composites. Compared with the binary composites with single-phase particles, the ternary composites with MWCNTs and spherical particles offer a good balance in glass transition temperature, electrical conductivity, stiffness and strength, as well as fracture toughness, exhibiting capacities in tailoring the electrical and mechanical properties of epoxy composites. Based on the fracture surface analysis, the complicated interactions between multiscale particles and the relative toughening mechanisms were evaluated to explain the enhancement in fracture toughness of the ternary composites.