接枝插层合成木质素基水凝胶的制备因素解析

Analysis of preparation factors of lignin-based hydrogels synthesized by graft-intercalation

以桑枝木质素提取物、丙烯酸为单体,以N,N′-亚甲基双丙烯酰胺为交联剂,以柠檬酸改性蒙脱土为插层剂,以(NH4)S2O8为引发剂,采用接枝插层制备木质素基水凝胶.利用均匀设计法优化获得适宜的组分配伍并解析组分间交互作用,通过SEM和FTIR分析技术表征制备水凝胶物相结构,探讨制备水凝胶对Mn2+、Zn2+、Pb2+的吸附性能.结果表明,当N,N′-亚甲基双丙烯酰胺质量为3.9730 g、木质素质量为0.7000 g、蒙脱土质量为0.1470 g时,制备水凝胶呈较规整蜂窝状多孔结构,且表面具有—OH、C=H、N—H等官能团;制备水凝胶表面功能基团和空间构型对其吸附性能影响显著;吸水120 min溶胀率达60%,自然风干70 h保水率达20%;处理初始质量浓度分别为320、160、1000 mg·L-1的Mn2+、Zn2+、Pb2+溶液720 min,吸附量各达77.09、73.95、383.90 mg·g-1,表现出对金属离子良好的吸附性能.

Using mulberry branch lignin extract、acrylic acid as monomers, N,N′-methylene bisacrylamide as cross-linker, citric acid modified montmorillonite as intercalator and ammonium persulphate as initiator, making lignin-based hydrogels through graft polymerization method. Uniform design method was used to optimize the distribution of components and analyzed the interaction between components, the phase structure of the hydrogels was characterized by SEM and FTIR, and the adsorption performance of prepared hydrogels on Mn2+, Zn2+ and Pb2+ were investigated. The results showed that: When the raw materials were composed of 3.9730 g N,N′-methylene bisacrylamide, 0.7000 g lignin and 0.1470 g montmorillonite, there was regular honeycomb-like porous structure with —OH, C=O,N—H functional groups on its surface. The surface functional groups and spatial configuration of prepared hydrogels significantly affected its adsorption properties. The swelling rate reached 60% within 120 minutes, besides after 70 hours of natural drying, the water retention rate reached 20%;The Mn2+, Zn2+, and Pb2+ solutions with initial mass concentrations of 320, 160, and 1000 mg·L-1 were treated for 720 min, and the adsorption capacities were 77.09, 73.95, and 383.90 mg·g-1, respectively, and the hydrogels showed great adsorption performance for metal ions.