一种新型甜菜碱表面活性剂N, N' , N'' -十二烷基二乙烯三胺五乙酸钠的合成与性能评价

Synthesis and Performance Evaluation of a Betaine Trimeric Surfactant Penta Sodium N，N'，N''- Dodecyl Diethylene Triamine Pentaacetic Acid

周明 乔欣 邱丹 于双 陈欣 江万雄 解忠强 曹静

ZHOU Ming QIAO Xin QIU Dan YU Shuang CHEN XIN JIANGWanxiong XIE Zhongqiang CAO Jing

以二乙烯三胺五乙酸、氢氧化钠和溴代十二烷为原料，通过中和反应和亲核取代反应合成了一种甜菜碱表面活性剂——N，N'，N'' -十二烷基二乙烯三胺五乙酸钠（DDTP），通过核磁氢谱和红外光谱对化合物的结构进行表征，测定了不同浓度的DDTP水溶液的表面张力，得出表面张力曲线，进而算出其他相关参数。实验结果证明：合成的化合物结构与预期的表面活性剂结构相吻合，在25℃时，临界胶束浓度ccmc=1.1×10-2 mmol/L，相应的表面张力γcmc=33.2 mN/m；表面张力降低20 mN/m时所需表面活性剂浓度的负对数pC20=3.22，饱和吸附量Γmax=5.15×10-3 mol/cm2，平均每个分子占有的最小面积Amin=3.1 nm2，表明N，N'，N'' -十二烷基二乙烯三胺五乙酸钠具有较好的表面活性。图6参18

A type of betaine trimeric surfactant，penta sodium N，N'，N'' - dodecyl diethylene triamine pentaacetic acid，was synthesized by alkali neutralization reaction and nucleophilic substitution reaction with diethylene triamine pentaacetic acid，sodium hydroxide and dodecyl bromide as main raw materials. The structure of the product was characterized by 1H-NMR and FT-IR，and the surface tension curve and related parameters were acquired by surface tension measurements. The experimental results showed that the structure of the synthesized compounds was in conformity with the expected structure of surfactant，the critical micelle concentration（ccmc）was of 1.1 mmol/L，and the surface tension at ccmc（γcmc）was of 34 mN/m，pC20（negative logarithm of the surfactant's molar concentration C20，required to reduce the surface tension by 20 mN/m）was 3.22，the surface excess（Γmax）at air/solution interface was 5.15×10-3 mol/cm2 and the minimum area per surfactant molecule at the air/solution interface（Amin）was 3.1 nm2 at 25℃，which meaned that target product had good surface activity.