Mild alkaline separation of fiber bundles from eucalyptus bark and their composites with cellulose acetate butyrate

Abstract High surface lignin content (i.e. 34.6 %) sclerenchyma fiber bundles were successfully isolated with a yield of 71 % by a mild alkali (NaOH dosage of 5 wt%) extraction of eucalyptus (Eucalyptus globulus) bark under 100 °C for 60 min.. The mechanical properties of the composites prepared by hot pressing of cellulose acetate butyrate (CAB) sheets with the fiber bundles were evaluated. The fiber bundles exhibited good compatibility with CAB due to their hydrophobic fiber surfaces. The mechanical properties of the fiber bundle/ cellulose acetate butyrate composites revealed the maximum at a weight ratio of 25:75, which demonstrates the promise of utilizing these isotropic aligned fiber bundles as the reinforcement to the cellulose acetate butyrate without the addition of plasticizers for composite uses.