木质素磺酸钠的结构特征及用作烯酰吗啉水分散粒剂分散剂

采用紫外、凝胶色谱和化学滴定法分析了国内外5种木质素磺酸钠(木钠)的结构特征，发现Ultrazine Na的亲水基含量达5.46 mmol•g^-1，其亲水性最好;Kinsperse126的磺酸基含量达2.05 mmol•g^-1;广纸木钠的重均分子量达13000，石岘木钠为10000。以各木钠为分散剂，制备烯酰吗啉水分散粒剂(WG)，并测试其应用性能。以Kinsperse126为分散剂的WG悬浮率高达95.03%，以石岘木钠为分散剂的WG悬浮率为89.70%。木钠的分散能力随磺酸基含量和分子量的增加而提高，磺酸基对木钠的分散性能的贡献更大。首次采用Turbiscan LabExpert分散稳定仪测定烯酰吗啉WG悬浮液的稳定性，以Kinsperse126作分散剂的悬浮液稳定性最好，在15 min时才出现沉淀，厚度仅0.38 mm，广纸木钠为分散剂的悬浮液中颗粒粒径增幅仅0.59 μm。悬浮液的稳定性与木钠的分散能力正向相关，且分子量大的分散剂能减缓颗粒粒径的增长。

Structural characteristics of sodium lignosulfonates and its use as dispersant of dimethomorph water-dispersible granules

Structural characteristics of different sodium lignosulfonates (SLs),Kinsperse126,Ultrazine Na,Borresperse Na, GZMN, and SXMN were investigated with ultraviolet spectrum, gel chromatography and chemical titration.The total hydrophilic groups content of Ultrazine Na was 5.46 mmol•g^-1, which was the highest among these SLs.The sulfonic groups content of Kinsperse126 was 2.05 mmol•g^-1, which was the highest among these SLs.The weight-mean relative molecular weight (M_w) of GZMN was 13000, which was the largest of these SLs.M_w of SXMN was 10000.Each SL was used as dispersant of dimethomorph water-dispersible granules (WG) respectively.The properties of dimethomorph WG were also investigated.The suspending rate of the WG with Kinsperse126 was as high as 95.03%.The suspending rate of the WG with SXMN was 89.70%.The dispersion ability of SL increased with increasing content of sulfonic groups and increasing M_w.Moreover, the sulfonic groups content was more important than M_w.Turbiscan LabExpert was initially used to estimate the stability of dimethomorph WG’s suspension.The suspension with Kinsperse126 had the best stability, in which deposition did not appear until 15 min and the height of sediment was only 0.38 mm.Particle size increase in the WG’s suspension with GZMN was only 0.59 μm which was the lowest.The stability depended on the dispersion ability of SL; furthermore, a larger M_w could weaken particle size increase.