羧基和磺基甜菜碱表面活性剂的合成与溶液性质研究

Synthesis and properties of carboxybetaine and sulfobetaine surfactants

以棕榈酸和N,N-二甲基丙二胺为主要原料通过酰胺化缩合反应合成棕榈酰胺中间体,再分别与氯乙酸钠和3-氯-2-羟基丙磺酸钠经季铵化反应,合成棕榈酰胺二甲胺羧基甜菜碱(C16ZC)和棕榈酰胺二甲胺羟丙基磺基甜菜碱(C16ZS),测定了无机盐、温度对表面活性剂的表面张力(γ)和临界胶束浓度(cmc)的影响,用Gibbs胶束公式计算了表面性能参数,并探讨了无机盐对表面活性剂溶液黏度的影响。实验结果表明,C16ZC的cmc低于C16ZS,无机盐的加入对C16ZC的cmc以及临界胶束浓度下的表面张力(γcmc)的影响大于C16ZS,二价盐Ca Cl2对cmc的影响比一价盐Na Cl更大。温度上升,2种甜菜碱的cmc和γcmc略有降低。热力学参数表明,C16ZC的Gibbs自由能比C16ZS更小,易于形成胶束,且2种甜菜碱形成胶束的过程均属于熵驱动。适量无机盐的加入有利于甜菜碱表面活性剂的增稠,C16ZC的溶液黏度比C16ZS对无机盐更敏感。

Palmitic acid and N,N- dimethyl- 1,3- propane diamine were used as starting materials to synthesize the palmitic amide intermediate,which further reacted separately with sodium chloroacetate and sodium 3- chloro- 2- hydroxy propane sulfonate via quaterization process to prepare palmitic amide dimethyl amino- carboxybetaine surfactant（ C16ZC） and palmitic amide dimethyl amino hydroxy- propyl sulfobetaine surfactant（ C16ZS） respectively. The effects of salts and temperature on the surface tension and critical micelle concentration（ cmc） of the surfactants were measured and determined. The viscosity of solution of C16 ZC and C16 ZS were measured and discussed. The thermodynamic parameters were calculated in accordance with Gibbs micelle equations from the cmc of C16 ZS and C16 ZC at different temperature. Results showed that the cmc of C16 ZC are lower than that of C16 ZS while effect of inorganic salt on cmc and corresponding surface tension（ γcmc） of C16 ZC is higher than that of C16 ZS,and effect of divalent salt（ such as Ca Cl2） is even more higher than that of monovalent salt（ such as Na Cl）. As temperature rises,cmc andγcmcof both C16 ZC and C16 ZS decline slightly. The thermodynamic parameters showed that micellization process for both products is found to be entropy- driven and C16 ZC is easy to form micelle as a result of much lower Gibbs free energy for micellization（ ΔGθmic） compared with that of C16 ZS. Addition of suitable dosage of inorganic salt can increase the viscosity of both products,and viscosity of C16 ZC is more sensitive to inorganic salt than that of C16 ZS.