摘要/Abstract

全氟辛基磺酸/全氟辛酸（PFOS/PFOA）类氟碳表面活性剂是性能最好、应用最广的一类氟碳表面活性剂，然而该类氟碳表面活性剂已被列为自然界中最难降解的有机污染物之一，采取引入氟碳支链的策略研发PFOS/PFOA替代物，以全氟-2-甲基-2-戊烯为原料合成了含CF₃CF₂CF₂C（CF₃）₂基团氟碳表面活性剂.表面活性研究表明，亲水基团种类对该类结构氟碳表面活性剂表面性能影响较大，亲水基团为氧化铵时表面活性最好.连接基团长短与亲水基团大小对表面活性影响一般，但提高两者的刚性可以有效提高表面活性.表面活性剂化合物中的羰基与带正电荷的氮原子会产成分子内相互作用，增强分子的刚性，进而提高表面活性.氧化铵型氟表面活性剂的临界胶束浓度为1.73×10^-2 mol/L，临界胶束浓度时可使水的表面张力降低至19.93 mN/m，其与APG0810复配时具有极好的协同效应，在基本不改变表面张力的情况下，氟碳表活性剂的使用量可降低100倍.
关键词: 全氟-2-甲基-2-戊烯, 支链型氟碳表面活性剂, 表面张力, 复配性能
Perfluorooctane sulphonate (PFOS) and perfluorooctanoic acid (PFOA) are one of the most prominent fluorosurfactants and these compounds have the most widely applications. However, such fluorocarbon surfactants have been listed as one of the most difficult to degrade organic pollutants in nature. Perfluoro-2-methyl-2-pentene was used as starting material to introducing fluorinated branch for synthesizing non-bioaccumulable alternatives. Fluorinated surfactants containing CF₃CF₂CF₂C(CF₃)₂ group were successfully synthesized. The surface tension tests showed the hydrophilic groups have a great influence on the surface properties in aqueous solution, and the compound showed the best surface activities when the hydrophilic group was ammonium oxide. The length of the linking group and the size of the hydrophilic group have a general effect on the surface activity, but increasing the rigidity of the two groups can effectively increase the surface activity. The carbonyl group in the surfactant compound and the positively charged nitrogen atom will produce intramolecular interactions, enhance the rigidity of the molecule, and thus increase the surface activity. The critical micelle concentration (cmc) value of the fluorinated surfactant with ammonium oxide as headgroup was about 1.73×10^-2 mol/L and the surface tension in water was 19.93 mN/m at the cmc. A excellent synergism was found when it was mixed with APG0810, the use of fluorocarbon surfactant can be reduced by a factor of 100, whereas the surface tension is basically unchanged.
Key words: perfluoro-2-methyl-2-pentene, branched fluorinated surfactants, surface tension, combined properties


PDF全文下载地址:

点我下载PDF