Thermal and electrical behaviors of a poly(epoxy) coating with high electrical conductivity used for aeronautic applications are investigated. The poly(epoxy) used is designed for resin transfer molding (RTM) applications, it have a low viscosity at room temperature (around 1 Pa s) and a high T g (>160 C). This study details the influence of silver nanowires with a high aspect ratio, on the thermal behavior such as the relative degree of reaction α and the kinetics parameters thanks to dynamic and isothermal differential scanning calorimetry. Conductivity measurements of surface and volume have permitted to determine a very low percolation threshold at around 0.7% in volume. The value of electrical conductivity above the percolation threshold is upper than 10 2 S m −1 and the lowest surface resistivity was measured around 13 mΩ sq −1 both for 8% in volume of AgNWs. This kind of coating has a great interest for lightning strike protection of aircraft parts due to the high electrical conductivity obtained with a low overweight.

A new kind of high electrical conductive epoxy coating with low filler rate was investigated for lightning strike protection (LSP) of carbon fiber reinforced polymer (CFRP). The coating without CFRP substrate was firstly studied. The influence of silver submicronic wires (AgSWs) with a high aspect ratio on the electrical behavior is observed; that is, the electrical resistivity evolution, the current density value, and the electrical conduction mechanisms as function of temperature. The preponderant electrical conduction mechanism is an Ohmic behavior. The higher level of conductivity obtained is 5.5 × 105 S m−1 for 9% vol of AgSWs. Lightning strike tests were carried out on an epoxy/AgSWs coating filled with 8% in volume (74 gsm) and deposited on a CFRP. The ultrasonic testing after lightning strike on coated CFRP shows no structural delamination and demonstrates the interest of this new route for an efficient LSP. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 137, 48700.