Improvements in the carbonisation of viscose fibres

Abstract

The maximum theoretical carbon yield for the carbonisation of viscose fibres, which consist of the renewable resource cellulose, is 44%. In reality the carbon yield is just in the range of 20%. By chemical activation of viscose fibres, carbon yields of more than 30% were achieved along with a reduction of undesired tar formation by 75%. A further increase in carbon yield was realised by supplemental incorporation of carbon black into the cellulose matrix of the viscose fibres. The chemical activation did not change the state of chemical bonding of the carbon atoms and the supramolecular structure within the carbonised fibres. Also the fibre morphology remained unchanged in terms of shape of cross section and surface structure. However, activated viscose fibres delivered carbon fibres with a much higher specific surface area. Carbon fibres from activated viscose fibres provide a similar or even improved application potential as carbon fibres from standard viscose fibres.