Structure Evolution in Polyethylene‐Derived Carbon Fiber Using a Combined Electron Beam‐Stabilization‐Sulphurization Approach. Issue 10 (17th July 2021) - Frank, Erik
Abstract: A new approach is described for the production of poly(ethylene) (PE) derived carbon fibers (CFs) that entails the melt spinning of PE fibers from a suitable precursor, their cross‐linking by electron beam (EB) treatment, and sulphurization with elemental sulphur (S8 ), followed by pyrolysis and carbonization. Instead of focusing on mechanical properties, analysis of CF structure formation during all process steps is carried out by different techniques comprising solid‐state nuclear magnetic resonance spectroscopy, thermogravimetric analysis coupled to mass spectrometry/infrared spectroscopy, elemental analysis, energy dispersive X‐ray scattering, scanning electron microscopy, Raman spectroscopy, and wide‐angle X‐ray diffraction. A key step in structure formation is the conversion of PE into poly(thienothiophene)s during sulphurization; these species are stabile under inert gas up to 700 °C as confirmed by Raman analysis. Above this temperature, they condense into poly(napthathienophene)s, which are then converted into graphite‐type structures during pyrolysis. Abstract : Structure evolution during the conversion of melt spun, electron beam‐crosslinked polyethylene fibers into carbon fibers using a combined sulphurization/pyrolysis/carbonization process is reported. Solid‐state nuclear magnetic resonance spectroscopy, thermogravimetric analysis–mass spectrometry, infrared spectroscopy, energy dispersive X‐ray scattering, scanning electron microscopy, Raman spectroscopy, and wide‐angle X‐ray diffraction data are presented and provide a comprehensive picture of the structural changes during carbonization.