Preparation of Eucalyptus pulp by mild condition of low-temperature, atmospheric pressure, and short-reaction-time with high-boiling-point solvent and pulp properties

Chemical pulp was prepared by the low-temperature, atmospheric pressure, and short reaction time pulping of Eucalyptus wood chips using a high-boiling-point solvent. The pulping conditions and pulp properties were evaluated. After the digestion of the Eucalyptus chips, pulp containing 6% residual lignin was obtained in 59.6% yield. It exhibited a low shive content and a sufficiently pulped appearance. With subsequent digestion at 110 °C for 60 min, the shive content further decreased, and fiber bundles disintegrated by simple mechanical stirring. The fiber length and width of the pulp were 500–577 and 20.1–27.9 μm, respectively, and the fiber roughness was 8.8–16.8 mg/100 m. The degree of crystallization of the pulp proportionally increased with cooking temperature. The brightness of the pulp with ~ 6% residual lignin content was greater than 52% ISO, and the zero-span tensile strength and viscosity gradually increased with pulping time.