双十二烷基甲基羟丙基磺基甜菜碱的合成与性能

以异丙醇/水为溶剂,在碳酸钠和碘化钾存在下,用双十二烷基甲基叔胺和3-氯-2-羟基丙磺酸钠反应合成了双十二烷基甲基羟丙基磺基甜菜碱(diC12HSB),经红外、质谱、核磁表征确认为目标产物。由于具有双长链烷基,diC12HSB水溶性较差,但具有良好的油溶性。25℃下diC12HSB在水/空气界面的饱和吸附量达到7.0×10-10mol/cm2,相应的分子截面积为0.237 nm2,其临界胶束浓度约为1.8×10-5mol/L,γcmc<31 mN/m,即具有优良的表面活性。通过与亲水性磺基甜菜碱或羧基甜菜碱以及烷醇酰胺乙氧基化物类非离子表面活性剂复配,混合物中diC12HSB的摩尔分数为0.25~0.3,可在表面活性剂总质量分数为0.01%~0.3%范围内将大庆原油/地层水的界面张力降至超低,无需添加任何碱或无机盐。因此,diC12HSB可用作无碱驱油用表面活性剂。

Synthesis and Properties of Didodecyl Methyl Hydroxyl Propyl Sulfobetaine

An amphoteric surfactant,didodecyl methyl hydroxyl propyl sulfobetaine （diC12HSB）,was synthesized by reaction of the corresponding tertiary amine with 3-chloro-2-hydroxyl propyl sulfonate in the presence of Na2CO3 and KI with isopropanol/water mixture as solvent at 85 ℃.The molecular structure of the product was confirmed by FT-IR,mass spectrum and 1HNMR respectively.Due to the two long hydrocarbon chains,diC12HSB is only slightly water soluble but with good solubility in oils.At 25 ℃ diC12HSB has a high saturated adsorption at air/water interface,7.0 ×10-10 mol/cm2,and correspondingly a low cross section area,0.237 nm2,with the cmc and γcmc being estimated to be 1.8 × 10-5 mol/L,and ＜ 31 mN/m,respectively,which indicates that diC12 HSB is highly surface active.By mixing with hydrophilic sulfobetaine or hydrophilic carboxyl betaine and nonionic surfactants such as alkanolamide ethoxylates,where diC12HSB has a molar fraction between 0.25 and 0.3,the mixed surfactants can reduce the Daqing crude oil/connate interfacial tension to ultralow,or 10-3 mN/m magnitude,in a total surfactant concentration range from 0.01％ to 0.3％,without adding any alkali or neutral electrolyte.diC12HSB is thus a potential surfactant for surfactant-polymer flooding free of alkali.