| The sulfonated imidazole ionic liquid surfactant is a new type of non-halogen ionic liquid surfactant which containing the sulfonic acid anion.Unlike the conventional ionic liquid surfactant and sulfonate surfactant,due to the change of product special structure,the performance of the products have changed greatly.Furthermore,it takes a long time to synthesize the ionic liquid surfactant by traditional methods,and the microwave radiation technology is widely used in organic synthesis because of its fast heating speed,uniform material heating characteristics.In this dissertation,the synthetic route of three classes of ionic liquid surfactants include:1-alkyl-3-methylimidazolium-benzenesulfonate[Cnmim][Bsa](n=12,14,16);Ionic liquid-type Gemini imidazolium surfactants[Cn-2-Cnim]Br2(n=8,10,12,14);Ionic liquid-type Gemini imidazolium surfactants which containing sulfonic groups[Cn-2-Cnim][Bsa]2(n=8,10,12,14)were studied.These three classes of ionic liquid surfactants were synthesized by quaterisation and anion exchange reaction with imidazole(or N-methylimidazole),bromoalkanes and sodium benzenesulfonate as raw materials via microwave-assisted synthesis.The reaction conditions of microwave-assisted synthesis were optimized by single factor experiments,and the effects of reaction temperature,microwave power,reaction time and feed ratio on the yield were investigated.Ultimately,synthetic products was determined by the orthogonal experiment the optimum synthetic technology conditions of each step.After purification,the products were characterized by IR and 1HNMR.The surface/interfacial tension,wettability property,foam property and emulsifying property of three classes of products were evaluated to summarize the mechanism how the molecular structure of ionic liquid surfactant influence their properties.The experimental results obtained are as follows:1-alkyl-3-methylimidazolium-benzenesulfonate optimum synthesis conditions for(quaterisation):microwave power 300W,temperature 53℃,reaction time 6 min,feed ratio of n 甲基咪哩:n 溴代烷烃 was 1:1.1,yield is 93.29%.Ionic liquid-type Gemini imidazolium surfactants[Cn-2-Cnim]Br2 optimum synthesis conditions for(quaterisation):microwave power 600W,temperature 45℃,reaction time 6 min,feed ratio of 咪哩:n1,2-二溴乙烷 was 3.2:1,yield is 63%.Ionic liquid-type Gemini imidazolium surfactants containing sulfonic groups[Cn-2-Cnim][Bsa]2 optimum synthesis conditions for(anion exchange reaction):microwave power 400W,temperature 105 C,reaction time 10 min,feed ratio of n[Cn-2-Cnim]Br2:n苯磺酸钠 was 1:2,yield is 65.92%.Moreover,the IR and nuclear magnetic 1HNMR showed that the molecular structures of the synthesized products are consistent with the expected design goal product.The critical micelle concentration of various series of products are determined by surface tension method and conductivity method.The results show that,the surface activity of Ionic liquid-type Gemini surfactants which containing sulfonic groups[Cn-2-Cnim][Bsa]2 are significantly enhanced by introducing sulfonic acid group.And it is found that among the three classes of target products,the surface activity of mono ionic liquid surfactants[Cnmim][Bsa]is the best,its minimum achievable of γCMC is 19.37mN/m;The interfacial tension value of each series of products are determined by spinning drop method,it shows that the interfacial activity of two kinds of Gemini ionic liquid surfactants([Cn-2-Cnim]Br2 and[Cn-2-Cnim][Bsa]2)are obviously better than that of the monomer product[Cnmim][Bsa],their interfacial tension can be reduced by an order of magnitude,the minimum can reach 0.0016mN/m,and both of them are all suitable for the weak alkali flooding system.Besides,the interfacial activity of[Cn-2-Cnim][Bsa]2 is improved after introducing sulfonic groups into[Cn-2-Cnim]Br2;We adopt contact angle method and water measuring cylinder method confirm that the synthesis of[Cnmim][Bsa]compared with the other two gemini products([Cn-2-Cnim]Br2 and[Cn-2-Cnim][Bsa]2)show better properties of wettability and foam.The minimum wetting angle of[Cnmim][Bsa]is 5.77°,and the foam stability of[Cnmim][Bsa]can be sustained 1.5h;The emulsifying properties of various series of products are determined by colorimetry and water evolution time method,the results show that the emulsion stability of two ionic liquid-type gemini surfactants([Cn-2-Cnim]Br2 and[Cn-2-Cnim][Bsa]2)are better than that of the mono-product[Cnmim][Bsa],but the emulsifying ability of[Cnmim][Bsa]is much stronger than that of[Cn-2-Cnim]Br2 and[Cn-2-Cnim][Bsa]2.In conclusion,the surface activity and oil displacement performance of ionic liquid surfactants can be remarkably improved by introducing sulfonic acid groups into the molecular structure. |
PDF Full Text Request