Insight into stabilization behaviors of Lignin/PAN-derived electrospun precursor fibers

Abstract

The stabilization behaviors of Lignin/PAN-derived electrospun precursor fibers under the different temperatures and different heating rates were investigated to reveal the effects of oxygen structural unit of Lignin on the oxidation and cyclization reaction of fibers. The results indicated that the introduced Lignin could helpfully reduce the cyclization degree of fibers, accomplishing the stabilization process at a lower temperature. Meanwhile, the introduced Lignin could efficiently attenuate the exothermal rate of fibers, accomplishing the stabilization process with a higher heating rate. Moreover, the abundant oxygen-containing groups in Lignin acted as a free-radical scavenger to slow down the free radical cyclization rate of fibers in the low stabilization temperature stage (<240 °C), while the carboxyl group in Lignin served as an initiating agent to accelerate the ionic cyclization of fibers in the high stabilization stage (>280 °C). It has been established that the oxygen structural unit of Lignin could be a promising candidate to facilitate the stabilization behaviors of PAN-derived fibers.