桑枝莱赛尔纤维溶解浆制备及其性能

Preparation and properties of mulberry dissolving pulp for Lyocell fiber

关键词:  桑枝  莱赛尔溶解浆  预水解硫酸盐法制浆  二氧化氯漂白  流变性能

Key Words:mulberry branches, Lyocell dissolving pulp, pre-hydrolyzed sulfate pulping, chlorine dioxide bleaching, rheological properties

摘要:为探索可再生桑枝资源制备莱赛尔级溶解浆的可行性，以桑枝为原料，采用预水解硫酸盐法蒸煮、漂白和酸处理工艺制备了桑枝莱赛尔纤维溶解浆。考察了预水解硫酸盐蒸煮、二氧化氯-冷碱抽提-二氧化氯漂白及酸处理等工艺对溶解浆关键技术指标（如α-纤维素含量、聚合度、白度、灰分以及金属离子含量）的影响；不同漂白序列对浆粕聚合度和白度的影响；对浆粕吸收溶剂速率、纺丝原液流变性能进行分析。结果表明，所得浆粕的α-纤维素含量为92.8%，白度为85% ISO，聚合度为655，灰分为0.09%，铁离子含量为4 mg/kg，铜离子含量为3 mg/kg，达到Lyocell纤维纺丝用标准。在50% NMMO水溶液中，90℃抽真空0.05 MPa条件下，浆粕具有良好的溶解性，35 min左右溶解完全。

Abstract:In order to explore the feasibility of preparing Lyocell grade dissolving pulp from renewable mulberry branch resource, mulberry branch dissolving pulp for Lyocell fiber was prepared by pre-hydrolyzed sulfate cooking, bleaching and acid treatment processes using mulberry branches as raw materials. The effects of pre-hydrolyzed sulfate cooking, chlorine dioxide-cold alkali extraction-chlorine dioxide bleaching and acid treatment on the key technical indexes of dissolved pulp (such as α-cellulose content, degree of polymerization, whiteness, ash content and metal ion content), the effects of different bleaching sequences on the whiteness of pulp polymerization, the solvent absorption rate of pulp and the rheological properties of spinning stock solution were analyzed. The results showed that the dissolving pulp prepared by mulberry branches reached the standard of Lyocell fiber spinning, and the α-cellulose content of the pulp was 92.8%, the whiteness was 85% ISO, the degree of polymerization was 655, the ash content was 0.09%, the iron ion content was 4 mg/kg, and the copper ion content was 3 mg/kg, and it had good solubility under the condition of 50% NMMO water content and 0.05 MPa vacuum at 90°C. It was completely dissolved in about 35 min.