Abstract: Polyimide(PI)-based carbon fibers with different properties were prepared by carbonization of PI fibers at 800°C Polyimide(PI)-based carbon fibers with different properties were prepared by carbonization of PI fibers at 800°C, followed by heat treatment from 800 to 2 800°C. The effect of heat treatment temperature (HTT) on elemental composition, surface morphology, mechanical properties, and the thermal and electrical conductivities of PI-based carbon fibers were investigated by elemental analysis, SEM, HRTEM, Raman spectroscopy, mechanical testing, and electrical and thermal conductivity measurements. Results showed that as a result of HTT the carbon content increased from 78. 97% to 99. 72%, the tensile strength exhibited a maximum of 924. 4 MPa, and the degree of graphitization and the size of graphite crystallites were both increased. Distinct reductions in strain-to-failure and electrical resistivity were observed with increasing HTT. The thermal conductivity can reach 228. 4 W · m ^-1 · K ^-1 after heat treatment at 2 800 °C. PI fiber may be a good precursor for carbon fibers with a high thermal conductivity. Polyimide(PI)-based carbon fibers with different properties were prepared by carbonization of PI fibers at 800 Polyimide(PI)-based carbon fibers with different properties were prepared by carbonization of PI fibers at 800°C Polyimide(PI)-based carbon fibers with different properties were prepared by carbonization of PI fibers at 800°C, followed by heat treatment from 800 to 2 800°C. The effect of heat treatment temperature (HTT) on elemental composition, surface morphology, mechanical properties, and the thermal and electrical conductivities of PI-based carbon fibers were investigated by elemental analysis, SEM, HRTEM, Raman spectroscopy, mechanical testing, and electrical and thermal conductivity measurements.
Results showed that as a result of HTT the carbon content increased from 78. 97% to 99. 72%, the tensile strength exhibited a maximum of 924. 4 MPa, and the degree of graphitization and the size of graphite crystallites were both increased. Distinct reductions in strain-to-failure and electrical resistivity were observed with increasing HTT. The thermal conductivity can reach 228. 4 W · m ^-1 · K ^-1
after heat treatment at 2 800 °C. PI fiber may be a good precursor for carbon fibers with a high thermal conductivity. Polyimide(PI)-based carbon fibers with different properties were prepared by carbonization of PI fibers at 800°C, followed by heat treatment from 800 to 2 800 °C. The effect of heat treatment temperature (HTT) on elemental composition, surface morphology, mechanical properties, and the thermal and electrical conductivities of PI-based carbon fibers were investigated by elemental analysis, SEM, HRTEM, Raman spectroscopy, mechanical testing, and electrical and thermal conductivity measurements.Results showed that as a result of HTT the carbon content increased from 78. 97% to 99. 72%, the tensile strength exhibited a maximum of 924. 4 MPa, and the degree of graphitization and the size of graphite crystallites were both increased. Distinct reductions in strain-to-failure and electrical resistivity were observed with increasing HTT. The thermal conductivity can reach 228. 4 W · m ^-1 · K ^-1 after heat treatment at 2 800°C. PI fiber may be a good precursor for carbon fibers with a high thermal conductivity., followed by heat treatment from 800 to 2 800°C. The effect of heat treatment temperature (HTT) on elemental composition, surface morphology, mechanical properties, and the thermal and electrical conductivities of PI-based carbon fibers were investigated by elemental analysis, SEM, HRTEM, Raman spectroscopy, mechanical testing, and electrical and thermal conductivity measurements. Results showed that as a result of HTT the carbon content increased from 78. 97% to 99. 72%, the tensile strength exhibited a maximum of 924. 4 MPa, and the degree of graphitization and the size of graphite crystallites were both increased. Distinct reductions in strain-to-failure and electrical resistivity were observed with increasing HTT. The thermal conductivity can reach 228. 4 W · m ^-1 · K ^-1 after heat treatment at 2 800 °C. PI fiber may be a good precursor for carbon fibers with a high thermal conductivity, followed by heat treatment from 800 to 2 800 °C. The effect of heat treatment temperature (HTT) on elemental composition, surface morphology, mechanical properties, and the thermal and electrical conductivities of PI-based carbon fibers were investigated by elemental analysis, SEM, HRTEM, Raman spectroscopy, mechanical testing, and electrical and thermal conductivity measurements. Results showed that as a result of HTT the carbon content increased from 78. 97% to 99. 72%, the tensile strength exhibited a maximum of 924. 4 MPa, and the degree of graphitization and the size of graphite crystallites were both increased. Distinct reductions in strain-to-failure and electrical resistivity were observed with increasing HTT. The thermal conductivity can reach 228. 4 W · m ^-1 ·  K ^-1 after heat treatment at 2 800°C. PI fiber may be a good precursor for carbon fibers with a high thermal conductivity., followed by heat treatment from 800 to 2 800°C  . The effect of heat treatment temperature (HTT) on elemental composition, surface morphology, mechanical properties, and the thermal and electrical conductivities of PI-based carbon fibers were investigated by elemental analysis, SEM, HRTEM, Raman spectroscopy, mechanical testing, and electrical and thermal conductivity measurements. Results showed that as a result of HTT the carbon content increased from 78. 97% to 99. 72%, the tensile strength exhibited a maxi mum of 924. 4 MPa, and the degree of graphitization and the size of graphite crystallites were both increased. Distinct reductions in strain-to-failure and electrical resistivity were observed with increasing HTT. The thermal conductivity can reach 228. 4 W · m ^-1 · K ^-1 after heat treatment at 2 800°C. PI fiber may be a good precursor for carbon fibers with a high thermal conductivity.