Effects of ultraviolet irradiation on stabilization of textile-grade polyacrylonitrile fibers without photo-initiator for preparing carbon fibers

Abstract

The ultraviolet (UV) was irradiated on textile-grade polyacrylonitrile (PAN) fibers without photo-initiators to demonstrate the effective stabilization for preparing carbon fibers (CFs). The irradiation for as short as 20&#8239

min&#8239

at 75&#8239

°C generated radicals in the textile-grade PAN fibers, which accelerate stabilization, resulting in significant reduction of process time. In addition, stepwise irradiations from 75 to 200&#8239

°C by increasing UV power, and following thermal treatments to mimic continuous stabilization for 30&#8239

min total provided CFs with tensile strength and modulus of 2.43&#8239

±&#8239

0.4 and 195&#8239

8.6&#8239

GPa. Considering conventional thermal stabilization for at least 60&#8239

min and 5&#8239

h with special and textile PAN fibers, respectively, the incorporation of UV irradiation into the present system could effectively advance stabilization process to shorten duration and to produce low-cost CFs based on textile-grade PAN fibers as one of cheap precursors.