以六氟丙烯二聚体为基础的表面活性的合成与性能

Synthesis and properties of fluorinated surfactants based on hexafluoropropene dimmer

以六氟丙烯二聚体为原料,与2-二甲氨基乙胺反应制取了中间体N,N-二甲基-N'-(2-三氟甲基-1-五氟乙基)全氟丙烯基乙二胺,然后分别与四种不同碳链长度的溴代烷烃进行季铵化反应,得到四种季铵盐型含氟阳离子表面活性剂。经表面张力测试发现四种产物均有较好的表面张力性能,其水溶液的最低表面张力均接近25 mN·m-1,优于传统的碳氢表面活性剂;经接触角测试发现四种含氟表面活性剂均可以将水在PET(对苯二甲酸乙二醇酯)和石蜡界面上的接触角降低到20°左右,对水在疏水界面上的铺展有很好的促进作用。探讨了亲水头基大小对该类氟表面活性剂的影响,结果表明改变亲水头基大小对该类氟表面活性剂影响不大,并通过分析指出对其表面活性和润湿性能起主要作用的是氟碳链疏水端。它们的细微差别可以从疏水基团的排列形态和溶液表面的吸附状态角度解释。

Intermediate N, N-dimethyl-N＇-（ 2-trifluorometyl-1 -pentafluoroethyl ） perfluoropropenyl ethane diamine was prepared with hexafluoropropene dimmer and 2-（dimethylamino） ethylamine,which was used to prepare four quaternary ammonium cationic fluori- nated surfactants with bromoethane, 1 -bromobutane, 1 -bromohexane and 1-bromooctane respectively. The results of surface tension measurements indicated that all the four fluorinated surfactants displayed higher surface activity, and the minimum surface tension in aqueous solution were as low as 25 raN-m-l ,which was better than the traditional hydrocarbon surfactants. According to the contact angle measurements, they could reduce the contact angle between water and ethylene terephthalate as well as paraffin to 20~,which was favorable for the spreading of water on the two interfaces. The effects of the size of hydrophilic group on the performance of these cationic fluorinated surfactants were discussed. It showed that the size of hydrophilic group was insignificantly to their surface activi- ty while fluorocarbon chains could influence their surface activity and wetting properties dramatically on a count of strong hydropho- bicity. The detailed differences between the behaviors of these surfactants could be explained from the arrangement form of hydro- phobic groups and adsorption state on the air/water interface.