Polyaniline-based all-polymeric adhesive layer: An effective lightning strike protection technology for high residual mechanical strength of CFRPs

Carbon fiber reinforced plastics (CFRPs) are vulnerable to lightning strikes due to their low electrical conductivity and low heat resistance. A lightning strike can damage CFRP structure catastrophically. Most common lightning strike protection (LSP) technology, consists of expanded metal foils/films on top of composite structures. This technology possesses disadvantages such as increased weight, galvanic corrosion, expensive integration and repair costs. In the present study, authors introduce a novel, easy to apply and all-polymeric LSP material. A doped intrinsic conductive polymer i.e. Polyaniline (PANI) dispersed in a thermosetting cross-linking polymer divinylbenzene (DVB) has been used to prepare an adhesive layer of 0.25-0.4 mm thickness. CFRP structure coated with PANI-based LSP layer, when tested against simulated lightning impulse current of 100 kA, demonstrated effective dissipation of the current, rendering almost 100% safety to the CFRP structure. PANI showed the capability to create a 3-D conductive network due to its self-assembling property, which makes it superior compared to its counterpart carbon/metal nano-filler based LSP technologies. Almost 100% residual strength of PANI-LSP protected CFRPs is reported in this work.