Electrostatic Discharge Tests of Carbon Composite Materials with Conductive Resin

Carbon fiber composite is an increasingly common spacecraft material due to its favorable mechanical, thermal, and Radio Frequency (RF) properties. Despite the intrinsically conductive nature of the carbon fibers, it has been shown that the dielectric resin that binds the laminate together can cover much of the surface of the finished structure and pose a serious electrostatic discharge (ESD) concern. Previously recommended ESD mitigations such as abrading off the surface resin or applying a static-dissipative coating to the surface of the structure may not be amenable to all spacecraft design needs, and can be difficult to implement. The ideal solution to the carbon composite ESD problem is a material made entirely of constituents conductive enough not to pose any risk of ESD. We present test results for two carbon composite materials with conductive resins, PMT-F6-CL100 and PMT-F6-BP1, that do not discharge under severe electron exposure at cryogenic temperatures, conditions under which a standard formulation PMT-F6 produced copious discharges.