Factorial design approach applied to electrically and thermally conductivenylon 6,6

Increasing the thermal and electrical conductivity of typically insulating polymers, such as nylon 6,6, opens new markets. A thermally conductive resi n can be used for heat sink applications. An electrically conductive resin can be used in static dissipative and Electromagnetic Interference/Radio Fr equency interference shielding applications. This research focused on perfo rming compounding runs followed by injection molding and testing (tensile p roperties, volumetric electrical resistivity, and through-plane thermal con ductivity) of carbon filled nylon 6,6, The four carbon fillers investigated included a PAN-based carbon fiber (milled, 200 mu long), an electrically c onductive carbon black, vapor grown graphitic nanotubes, and Thermocarb [hi gh quality synthetic milled graphite]. Formulations were produced and teste d that contained varying amounts of a single carbon filler. Combinations of fillers were also investigated via conducting half of a 2(4) factorial des ign. It was determined that Thermocarb has the largest effect on the therma l conductivity. Increasing Thermocarb increases thermal conductivity. For c onductive resins containing only a single filler type, nanotubes caused the electrical resistivity (ER) to decrease the most, For the half fraction fa ctorial design formulations that contain at least one filler type at the hi gher level, the ER of the conductive resin ranged from 0.1 to 0.3 ohm-cm.