Kinetic studies on hot-stretching of polyacrylonitrile-based carbon fibers by using internal resistance heating Part ⅠChanges in resistivity and strain

摘要

The effects of the stretching stress applied duringhigh temperature heat-treatment of polyacrylonitrile (PAN)-basedcarbon fibers on the structural development and the properties ofthe fibers were investigated kinetically using internal resistanceheating. The temperature-time superposition could be applied tothe changes in structural parameters, resistivity and tensile strengthduring heat-treatment using the same shift factors. The applicationof the stretching stress effectively reduced the fractions of slowerrate processes and the activation energy of the structuraldevelopment in the temperature region below about 1800℃, andalso influenced on the structural features. The longitudinal straininduced during heat-treatment increased in proportion to thelogarithmic treatment time, showing different kinetics from that ofthe structural development.