Synthesis And Performance Of Cationic Gemini Surfactants With Triazole Groups

Cationic gemini surfactants with hetercocyclic groups are the new family members of surfactants.They are made up of two heterocyclic hydrophilic head group and two aliphatic chains linked by a rigid or flexible spacer. As a new surfactants, cationic gemini surfactants with heterocyclic groups owing to the existence of heterocyclic hydrophilic head groups, show many new properties. Cationic gemini surfactants with hetercocyclic groups are receiving widespread attention by researchers.Two cationic gemini surfactants with1,2,4-triazole groups [C12-s-C12tr]Br2(s=2,4) were synthesized from hyrazine monohydrate, ethyl formate, triethyl orthoformate, ethylenediamine,1,4-butanediamine, bromododecane. IR、1HNMR、13CNMR、ESI-MS spectra were used to confirm the chemical structures of the prepare compounds.The reaction conditions of1,2-bis(1-dodecyl-1,2,4triazole-4-yl)ethane bromide and1,4-bis(1-dodecyl-1,2,4-triazole-4-yl)butane bromide were optimized.(1)the optimal reaction conditions of formic hydrazide:medium methanol, hyrazine monohydrate was added slowly into ethyl formate, the ratio of hyrazine monohydrate and ethyl formate1.2:1, reaction temperature55℃, reaction time2h, to the yield88.35%;(2)the optimal reaction conditions of1,2-bis(1,2,4-triazole-4-yl)ethane:medium methanol, reaction temperature90℃, reaction time17h, the ratio of formic hydrazide,triethyl orthoformate and ethylenediamine2:4:1, to the yield58.45%;(3) the optimal reaction conditions of1,2-bis(1-dodecyl-1,2,4-triazole-4-yl) ethane bromide:dark condtion, medium DMF, reaction temperature80℃, reaction time24h, the ratio of1,2-bis(1,2,4-triazole-4-yl)ethane and1-bromododecane1:3, to the yield56.67%.(4)the optimal reaction conditions of1,4-bis(1,2,4-triazole-4-yl)butane:medium methanol, reaction temperature90℃, reaction time14h, the ratio of formic hydrazide,triethyl orthoformate and ethylenediamine2:4:1, to the yield55.89%;(5) the optimal reaction conditions of1,4-bis(1-dodecyl-1,2,4-triazole-4-yl) butane bromide:dark condtion, medium acetonitrile, reaction temperature80℃, reaction time24h, the ratio of1,2-bis(1,2,4-triazole-4-yl)ethane and1-bromododecane1:3, to the yield53.71%.Cationic gemini surfactants with1,2,4-triazole groups of dissolubility were researched, the results showed that they were well solube in polar solvents and sparingly solube in less polar solvents. At the same time,cationic gemini surfactants with1,2,4-triazole groups of critical micelle concentration and surface tension were researched.The values of CMC and γcmc of [C12-2-C12tr]Br2were0.631mmol/L and28.31mN/m; The values of CMC and γcmc of [C12-4-C12tr]Br2were0.398mmol/L and25.19mN/m. The results showed that they have superior surface properties compared with cationic gemini surfactants which containing the same aliphatic chains and spacer.