Wet spun polyacrylonitrile-based hollow-mesoporous carbon fiber: Stabilization, carbonization and its basic properties

Due to its unique structure, hollow-mesoporous carbon fibers would enlarge the applications of hollow fiber in the areas operating in the harsh environment. In this paper, polyacrylonitrile (PAN) -based hollow-mesoporous carbon fibers (HMCFs) with various carbonization temperatures were firstly fabricated by heat treatments including stabilization and carbonization with the hollow-mesoporous precursor fibers preparing with blending alkali lignin (AL). Unlike previously, a small amount of residue of AL (less than 1%) in the hollow-mesoporous fiber (HMF) would reduce the degree of cyclization although the activation energy of cyclization reaction reduces, and thus accelerate the thermal decomposition of HMF which shows a lower carbon yield eventually compared with PAN. The oxidative stability of fibers improves a lot when HMF is transformed into HMCF which is beneficial to use it in the poor conditions. This work explains the effects of residue of AL existing in the precursor fiber on the processes of stabilization and carbonization of HPCMs, and the relationships between basic properties of HMCFs including physical structure, chemical composition and relevant properties and carbonization temperature. It provides a new insight to fabricate HMF into HMCF by the heating treatments of stabilization and carbonization with the existence of AL. (C) 2019 Elsevier Ltd. All rights reserved.