Study On The Amination Of Unsaturated Alcohol And The Preparation And Performance Of Betaine Derivatives

In this paper, the unsaturated tertiary amine was synthesized by the method of one-step catalytic amination of oleyl alcohol firstly. Then the unsaturated alkyl carboxybetaine (UCB) and the unsaturated alkyl sulfohydroxybetaine (USB) were synthesized. Some physiochemical performances of the unsaturated betaines and the corresponding saturated betaines were studied, and the interfacial tensions between surfactant solutions and crude oil were investigated.In the reaction of catalytic amination, we found that the yield of tertiary amine can reach95.4%and the retention rate of unsaturated bond can reach93.3%with the Cu catalyst, which is better than the result of the traditional Cu/Ni catalyst.The UCB and USB were synthesized with the unsaturated tertiary amine. By the orthogonal experiment, we found that the optimum synthetic conditions for UCB are that the solvent is alcohol, the temperature is80℃, the time for synthesis is10h and the mole ratio of tertiary amine/sodium chloroacetate is1:1.2; the optimum synthetic conditions for USB are that the solvent is isopropyl alcohol, the temperature is80℃, the time for synthesis is8h and the mole ratio of tertiary amine/intermediate is1:1.2. The betaines were purified and characterized by IR and1H-NMR.The Krafft point, the isoelectric point and the surface activity were measured. The results show that the Krafft points of unsaturated betaines were below0℃and those of saturated betaines were above40℃. The isoelectric points of UCB and USB are8.2and8.0, respectively. The unsaturated alkyl betaine has a higher CMC value and a lower ycmc value compared with the saturated alkyl betaine. The impacts of pH values on the performances of the four betaines are not very obvious.The interfacial tensions between betaine solutions and Gudong crude oil (Shengli oilfield in China) were measured. The results indicate that the orders of the four kind of betaines for reducing interfacial tensions are UCB> CB (saturated carboxybetaine)> SB (saturated sulfohydrobetaine)> USB. With the additional concentration of NaCl increasing, the time of UCB achieving ultra-low interfacial tension decreases first and then increases, while the time of CB increases gradually. With the additional concentration of CaCl2increasing, the time of UCB achieving ultra-low interfacial tension increases and the interfacial tension of CB can not reach to ultralow value. The performances of NaCl tolerance and CaCl2tolerance of UCB are better than those of CB.