State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640, Guangdong, China.
State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640, Guangdong, China.
Int J Biol Macromol. 2018 Apr 1;109:1232-1238. doi: 10.1016/j.ijbiomac.2017.11.118. Epub 2017 Nov 21.
The dark color of industrial lignin is the main obstacle for their high value-added use in areas such as dyestuff dispersants. A kind of light-colored lignosulfonate with favorable dispersibility and remarkable stain resistance is prepared using fractionated eucalyptus kraft lignin. The fractionated lignins named as D (insoluble part) and X (soluble part) and sulfonated lignin fractions named as SD and SX are characterized by FTIR spectroscopy, H NMR spectroscopy, GPC and brightness test. The results reveal that fraction X presents a lower molecular weight but a higher hydroxyl content than that of fraction D, which lead to the differences on the SOH content, dispersibility and color performance of SD and SX. The sulfonated fractions perform a similar molecular weight to that of unsulfonated lignins and show light color due to the phenolic hydroxyl blocking of 1,4-BS (1,4-butane sultone) and the postprocessing of sodium borohydride. The SX that performs the best of all exhibits obvious decrease on phenolic hydroxyl groups and increase on brightness value which is improved by 85.8% compared with control sample. The SX reaches the highest level (grade 5) in the dispersibility test and presents remarkable stain resistance on different textiles, especially on the dacron and cotton.
工业木质素的深色是其在染料分散剂等高附加值领域应用的主要障碍。本文使用分级桉木硫酸盐木质素制备了一种具有良好分散性和显著耐污性的浅色木质素磺酸盐。通过傅里叶变换红外光谱（FTIR）、核磁共振氢谱（1H NMR）、凝胶渗透色谱（GPC）和白度测试对命名为 D（不溶部分）和 X（可溶部分）的分级木质素以及命名为 SD 和 SX 的磺化木质素进行了表征。结果表明，X 级木质素的分子量较低，但羟基含量较高，这导致 SD 和 SX 的 SOH 含量、分散性和颜色性能存在差异。磺化木质素与未磺化木质素具有相似的分子量，由于 1,4-BS（1,4-丁烷砜）的酚羟基封端和硼氢化钠的后处理，它们呈现浅色。所有磺化木质素中表现最好的是 SX，其酚羟基明显减少，白度值提高，与对照样品相比提高了 85.8%。在分散性测试中，SX 达到最高等级（5 级），并对不同的纺织品表现出显著的耐污性，特别是对涤纶和棉。
