Modification of Softwood bleached pulp suitable for viscose cellulose with high liquid water

摘要

Softwood pulp was used to prepare dissolving pulp suitable for viscose fiber by three procedures (liquid hot water, sodium hypochlorite oxidation and alkali extraction). The impacts of main factors, such as temperature, reaction time, concentration and chlorine loading on the methylcellulose content and the polymerization degree were investigated. Firstly, the pulp was pretreated by liquid hot water, Under the optimized conditions (concentration 9.0%, temperature 180 °C, treating time 40min), the methylcellulose content and the polymerization degree of pulp were 88.47% and 768, respectively. Secondly, the treated pulp was oxidized by sodium hypochlorite. Under the optimized conditions (chlorine loading 2.0%, treating temperature 50°C, treating time lh), the methylcellulose content and the polymerization degree were 91.54% and 528, respectively. Finally, the oxidized pulp was treated by sodium hydroxide ( alkali loading 13% ) under 20°C for lh. After these procedures, the methylcellulose content and polymerization degree were 95.85% and 536, respectively. The quality of cellulose fiber can meet the utilization requirement for viscose fiber production.