碱木质素改性及其纤维制备研究

Modification and fiber preparation of soda lignin

为改善碱木质素的熔融性能,实现熔融纺丝法制备碱木质素基纤维,以制浆造纸黑液粉末中提取的碱木质素为原料,与不同质量比的聚乙二醇-400(PEG-400)混合加热,再倒入水中搅拌不同时间后过滤干燥,测定改性处理后碱木质素的热稳定性、黏度及熔融纺丝性能等特征。结果表明:1)在相同搅拌时间时,不同质量比的PEG-400改性处理对灰分含量影响不大,木质素含量随质量比的增加而变少或不变;在相同质量比时,搅拌时间越长,灰分含量越少,木质素含量越多。2)经PEG-400改性处理的碱木质素的热分解温度增加,热稳定性能提高;但随着质量比或搅拌时间的增加,其热分解温度均减少,热稳定性能降低。3)质量比为1∶1和1∶2时PEG-400改性处理的碱木质素均表现出较差的熔融性能,而质量比为1∶3时PEG-400改性处理的碱木质素呈现较好的熔融性能,尤其是搅拌时间为2 h的碱木质素则表现出较稳定的熔融性能,并且能够在228℃温度下熔融纺丝制备得到直径约为(30±4.8)μm的碱木质素基纤维。

In order to improve the melting property of soda lignin and prepare soda lignin-based fibers by meltspinning,soda lignin isolated from black liquor was heated with polyethylene glycol-400（ PEG-400） at different mass ratios and then poured into water with different stirring time,followed by filtration and drying. The thermostability and viscosity as well as melt-spinning property of treated soda lignin were determined. The conclusions are obtained as follows. 1） Within the same stirring time,there was little effect of mass ratio on the ash content,but lignin content decreased with the increase of mass ratio; at the same mass ratio,longer stirring time resulted in the less ash content and higher lignin content. 2） The decomposition temperature of soda-lignin increased after the treatment with PEG-400,but it decreased with the increasing mass ratio or stirring time. 3） Poor melting properties were observed from the sodalignin treated by PEG-400 at the mass ratios of 1∶ 1 and 1∶ 2,while the soda-lignin treated by PEG-400 at the mass ratio of 1∶ 3 showed good melting property. Especially for the stirring time of 2 h,soda-lignin exhibited stable melting property and could be processed into lignin-based fibers with the average diameter of 30 ± 4. 8 μm by melt-spinning at the temperature of 228 ℃.