基于分子间作用力组装的镁铝水滑石光稳定剂及其性能研究

Performance of MgAl layered double hydroxides light stabilizer assembled via intermolecular forces

采用共沉淀-离子交换法制备了十二烷基硫酸根(SDS)插层镁铝水滑石(SDS-LDH),然后借助水滑石层间客体分子间作用力将光稳定剂2-羟基-4-正辛氧基二苯甲酮(UV-531)中性分子引入镁铝水滑石层间,构筑了共插层结构镁铝水滑石光稳定剂UV-SDS-LDH。采用XRD、FT-IR、UV-Vis和SEM等表征手段对其晶相结构、组成、紫外吸收性能和形貌进行表征。研究发现,UV-SDS-LDH形成了共插层结构,具有强的紫外吸收能力;插层组装大幅度提高了UV-531的耐迁移性,使其迁移率由83%降低至50.5%。由于其特殊的结构和组成,UV-SDS-LDH明显增强了聚丙烯(PP)的热稳定性和耐光老化性能,使PP 50%失重温度由411℃提高到441℃,光老化指数由65.9×10^(−3)减小至23.9×10^(−3),在PP领域具有潜在的应用价值。该研究为新型水滑石基功能材料的构筑和盐湖镁资源的利用提供了新思路。

Light stabilizer 2-hydroxy-4-n-octoxy-benzophenone(UV-531)and sodium lauryl sulfate(SDS)co-intercalated MgAl layered double hydroxides(UV-SDS-LDH)was assembled by taking the advantages of the intermolecular forces between UV-531 and SDS in SDS-LDH which was prepared firstly through a co-precipitation and anion-exchange method.The crystal structure,composition,ultraviolet absorption and morphology of the obtained UV-SDS-LDH were characterized by XRD,FT-IR,UV-Vis and SEM,which demonstrated that UV-SDS-LDH with co-intercalating structure had strong ultraviolet absorption capability and nanosheet morphology.The intercalation significantly improved the resistance migration of UV-531 with the migration rate reduced from 83%to 50.5%.The addition of UV-SDS-LDH into polypropylene(PP)matrix markedly enhanced the thermal stability and resistance to photoaging of PP with the 50%mass loss temperature increasing from 411℃to 441℃and the photoaging index reducing from 65.9×10^(−3) to 23.9×10^(−3) due to its special structure and composition,suggesting the hopeful application of UV-SDS-LDH in the field of PP.This work offers a new method for the preparation of novel LDH based functional materials and the utilization of Mg resources in salt lakes.