Abstract
Theconductivecompositesarepreparedbyepoxy(EP)andurethane(UR)resigndispersedwithnickel-coatedsericite(Ni-S)andcured.Variousfactorssuchasfillercontent,temperature,processing,curingconditionsandexpansioncoefficientofmatrixpolymerinfluencedonelectricalconductivityofthecompositesareinvestigatedexperimetally・Heatingbehaviorsofthesematerialsarealsocharacterizedbysurfacetemperaturemeasurements.Itwasfoundthatvolumeresistivitydecreasesexponentiallywithanincreaseoffillercontent,anddifferentcriticalcontentsinwhichvolumeresistivitychangestoanincreaseareobservedforeachcomposite.Thetemperatureandexpansionofmatrixpolymerdependenciesofresistivityofthecompositeswereshowntobeingoodcorrelation.Ni-S/URcompositesshowedthePositiveTemperatureCoefficient(PTC)effecthigherthanNi-S/EPcomposites.Ni-S/URcompositesshowedPTCeffectsbyheatingunderanincreasedenvironmentaltemperatureandalsoundersuppliedvoltage.
