Synthesis And Properties Of Alkyl Imidazolium Cation Surface Active Ionic Liquids

This paper aimed to synthesis a series of single nucleus surface active ionic liquids—1-alkyl-3-pentyl imidazolium（I） and1-alkyl-3-octyl imidazolium（II） and1,2-bis（N-alkylimidazolium-1-yl） ethane bromide（Cn-2-Cn）,1,4-bis （N-alkylimidazolium-1-yl） butanebromide（Cn-4-Cn）,1,4-bis（N-alkylimidazolium-1-yl） Phenylenebismethylene chloride（Cn-B-Cn） and study their main properties.Intermediates N-alkyl imidazole:Imidazole and1-Bromoalkane（1-Bdromopentane,1-Bromooctane,1-Bromodecane,1-Bromoadamantan,1-Bromotetradecane,1-Bromohexadecane） as raw materials,base on the example of N-octyl imidazole.the optimum syntheticconditions were determined：the ratio of imidazole to bromooctane was15:14,reaction timewas6h on room temperature,the yield was80.12%.I and II:Intermediates N-alkyl imidazole and1-Bromoalkane（1-Bdromopentane,1-Bromooctane,1-Bromodecane,1-Bromoadamantan,1-Bromotetradecane,1-Bromohexadecane） as raw materials,based on the example of II-3,The influence of reaction method,reactiontemperature,reaction time and molar ratio were investigated,the optimum synthetic conditionswere determined：the molar ratio of N-dodecyl imidazole to1-Bromododecane was1:1.05,the reaction temperature was50±2℃by ultrasonic assist method,the time reaction was12h,the yield was74.62%.Cn-2-Cn,Cn-4-Cn,Cn-B-Cn:N-octyl imidazole（N-decyl imidazole,N-dodecyl imidazole,N-myristyl imidazole,N-cetyl imidazole） reacted with1,2-Dibromethane,1,4-Dibromobutane,α,α’-Dichloro-p-xylene respectively,The optimized conditions was confirmed throughorthogonal design experiment:based on the example of C₁₀^-52-C₁₀,the molar ratio of N-octylimidazole to1,2-Dibromethane is2.4:1,reaction for10h on45±2°C by ultrasonic assistmethod,the yield was77.50%.Target products were characterized by1H-NMR and IR.The surfacetension,conductivity,wetting ability,emulsification ability, foam performance and bactericidalactivity of I,II,Cn-2-Cn,Cn-4-Cnand Cn-B-Cnwere examined.Surface tension measurement,thelower critical micelle concentration CMC values of C₁₆-2-C₁₆were8.12×10^-55mol/L on25℃,the minimum surface tension （γcmc） values were29.39mN/m, the lower critical micelleconcentration CMC values of C₁₆-2-C₁₆were1.01×10^-4mol/L on35℃, the minimumsurface tension （γcmc） values were27.72mN/m, The lower critical micelle concentration values of C₁₆-2-C₁₆were2.15×10^-4mol/L on50℃, the minimum surface tension （γcmc）values were26.15mN/m.Through determine wettability of Cn-2-Cn,Cn-4-Cn,Cn-B-Cn,C10^-52-C10and C10^-4-C10had better wettability when concentration was3.0g/L, wettabilitytime respectively were169s and160s.II-3had better emulsification ability whenconcentration was1.0g/L, emulsifying time was5137s. C₈-B-C₈have good foamperformance when the mass fraction of0.5%,the foam volume was130mL.The stability offoam of C₁₂-4-C₁₂was better.Through the bacteriostatic test, the bacteriostatic effect of II-3was better to Gram-bacteria （colibacillus）,bacteriostatic diameter was26mm.Thebacteriostatic effect of C₈-B-C₈was better to Gram-positive bacteria （Candidaalibicans）,bacteriostatic diameter was26mm.The bacteriostatic effect of C₈-2-C₈was betterto Gram-positive bacteria （Staphylococcus）,bacteriostatic diameter was22mm.