A new open-access study in the Journal of Materials Science provides the first systematic look at how Ioncell cellulose II fibers pyrolyze into carbon. Researchers from Aalto University and VTT heated regenerated cellulose fibers at different rates and found that slower heating significantly increases char yield, while the activation energy matches classic cellulose I behavior. The work also shows that the heat of pyrolysis is largely just the energy to evaporate levoglucosan, which simplifies furnace design. The study maps how fiber properties evolve with temperature, including shrinkage, elemental composition, and aromatic cluster growth. It debunks older claims of a special cellulose II carbonization mechanism, instead confirming general two-pathway models for non-graphitizable carbons. This dataset gives carbon fiber researchers a practical reference for optimizing thermostabilization and carbonization schedules, bringing bio-based carbon fiber closer to cost targets for mass-market applications.
