Abstract
This paper presents temperature dependence of electric resistance and Joule heat properties in carbon fiber reinforced polyethersulphone (PES) resin composites. The composite specimens were fabricated using recycled CFRP pieces or carbon fibers mixed with PES resin through an injection molding method. First, resistivitytemperature curves of the composites specimens were measured during heat cycles. Next, temperature rise due to Joule heat was measured and plotted against input power. Finally, resistivity of carbon fiber was measured for temperatures up to 473 K. It is found that resistivity of the composites obeys the percolation power law and shows the negative temperature coefficient (NTC) in the temperature range lower than load-deflection temperature of the resin. This NTC is proved to be mainly due to the NTC of carbon fiber. Resistivity at room temperature is reduced after each heat cycle. Temperature rise due to Joule heat is approximately proportional to input power per unit volume.
