Effect of fillers on electrical conductivity of epoxy resin under shear flow
Funabashi Masahiro; Kitano Takeshi
Abstract:The volume resistivity of conductive filler filled epoxy resin was measured under shear flow. A rheometer with double cylinder type sample cell was employed in order to measure the volume resistivity and shear stress under shear flow. The outer and inner cylinders of the rheometer were used as the electrodes. Nickel particles and two kinds of carbon fibers with different aspect ratios were used as the conductive fillers for the samples. It was found that the volume resistivity was affected by shear rate and the volume content and shape of fillers. The shear rate was varied from 10-2 to 102 sec-1. The minimum volume resistivity was observed for the fiber filled samples in a range of shear rate from 1 to 10 sec-1. The minimum volume resistivity indicated by shear rate for these samples changed when the aspect ratio and volume content of fibers were varied. The volume resistivity of the particle filled samples monotonously decreased with increasing shear rate. The almost same volume resistivity for the fiber filled samples was observed at the same shear stress, even though the aspect ratio and content of fibers were varied. At the same time, the particle filled samples showed the same tendency in relationship between shear stress and volume resistivity. Key Words:reinforced plastics, electromagnetic measurement, flow measurement, volume resistivity, shear flow, carbon fiber, nickel particle, epoxy resin, fiber orientation, double cylinder