Lightning damage suppression in a carbon fiber-reinforced polymer with a polyaniline-based conductive thermoset matrix

In this paper, the effectiveness of lightning damage suppression by a carbon-fiber-reinforced polymer (CFRP) laminate with a newly developed polyaniline (PANI)-based conductive thermosetting resin was experimentally examined by conducting simulated lightning and residual strength tests. We developed the PANI-based conductive thermosetting resin using dodecylbenzenesulfonic acid (DBSA) and p-toluenesulfonic acid (PTSA) as dopants and divinylbenzene (DVB) as a crosslinking agent, which improved the electrical conductivity and homogeneity of the resin. The electrical conductivity values for the PANI-based composite were 148 and 0.73 S/cm in the in-plane and out-of-plane directions, which are 5.92 times and 27.4 times greater than that of a conventional carbon fiber (CF)/epoxy composite, respectively. As a result, the PANI-based composite, when subjected to simulated lightning currents of −40 and −100 kA, showed dramatic improvements in lightning damage resistance compared to the conventional CF/epoxy composite. The residual strength examined by 4-point flexural testing after the simulated lightning test at −100 kA revealed only a 10% reduction from its initial strength, whereas the damaged CF/epoxy specimen tested at −40 kA showed a 76% reduction. Thus, the superior electrical conductivity of the CF/PANI composite quite effectively suppressed lightning damage without applying any lightning strike protection (LSP).