麦草碱木质素磺甲基化反应及性能的研究(英文)

Study of structural characterization of sulfomethylated wheat straw lignin

针对麦草碱木质素水溶性差、分子质量低、难以工业利用的问题,采用Fenton试剂为氧化剂,以亚硫酸钠为磺化剂对麦草浆碱木质素进行氧化再进行磺甲基化反应,得到质量分数为33%(Wt)的氧化磺甲基化碱木质素的溶液.红外光谱(FTIR)测试表明产物中具有磺酸基的特征吸收峰.利用凝胶渗透色谱(GPC)测得其重均分子质量达到6653 g.mol-1.通过紫外吸收光谱(UV)测得其最大吸收波长在276 nm处.通过碱木质素磺化反应前后的核磁共振(13C-NMR)测得磺甲基接入碱木质素中芳环的C-5位.当溶液质量浓度为30 g.L-1时,溶液表面张力为45.3 mN.m-1.

It is hard to utilize the wheat straw grass lignin as resource due to its in solubility in neutral aqueous and low molecular weight. In order to promote the utilization of it, sulfomethylation of wheat straw grass lignin is studied using Fenton reagent as oxidation reagent, sodium sulfite anhydrous and formaldehyde as sulfomethylation agent. The characterization of oxided and sulfometylated wheat straw grass lignin （OSWSL） is determined using FTIR, GPC,13C-NMR and UV. The results show that the average molecular weight of OSWSL （^-Mw） is 6653 g· mol^-1 which is greater than that of wheat strew lignin of 2828g· mol^-1. ^13C-NMR spectrum exhibits that the position of sulfomethylation reaction is C-5 in Guaiacyl suit, and the maximum absorption peak of UV is at 276 nm. When the solution concentration of OSWSL is 30 g· L^- 1, the surface tension is 45.3 mN·m^-1 .