Effect of the thermal stabilization temperature on the change in the texture of polyacrylonitrile fiber

Abstract

The effect of temperature of isothermal treatment on the change in sizes L010 of coherent scattering regions and texture of a polyacrylonitrile fiber during its transition to the structure of a thermally stabilized fiber is analyzed using X-ray structure analysis. An increase in the thermostabilization temperature at a constant stretching load stimulates simultaneously a more active increase in size L010 and texturing of polyacrylonitrile fibers at the initial stage. Active evolution of the phase transformation at temperatures 275–290°C during further thermostabilization is accompanied by a substantial decrease in the texture of the polymer that has not experienced the phase transformation by this instant.