Electrically conductive carbon fiber reinforced plastics induced by uneven distribution of polyaniline composite micron-sized particles in thermosetting matrix

We developed electrically conductive carbon fiber reinforced plastic (CFRP) for lightning strike protection by infusing carbon fiber (CF) woven fabric with a low viscosity liquid conductive thermosetting resin, providing a conductivity in the thickness direction of the CFRP of above 0.1 S/cm. The novel CFRP fabrication method uses a styrene derivative based thermosetting resin liquid dispersion including newly designed micron-size polyaniline (PANI)/dodecyl benzene sulfonic acid (DBSA) based composite particles. The dispersion liquid showed low viscosity and no viscosity increase at room temperature, and could penetrate into CF woven fabric and undergo a cross-linking reaction after heating to around 120 °C. Nine-layered stacked sheets were hot-pressed to make solid laminated composites with 50 vol% CF. The cross-section in the thickness direction was analyzed by optical microscopy, scanning electron microscopy, and electron probe microanalysis to determine the distribution of PANI/DBSA particles and CF per unit area. It was found that PANI/DBSA particles were located between the binding of the plain-woven CF, and showed a conductivity of 0.5 S/cm in the thickness direction, even when the PANI amount was as small as 4 wt%.