关键词: 多季铵盐, 黏弹性表面活性剂, 表面活性, 流变性

Abstract: Three kinds of multiple-quaternary ammonium surfactant CD3N-n (n=12,16,18,which represents the number of carbon atoms in the alkyl chain) were synthesized with diethylamine hydrochloride,epichlorohydrin and long alkyl chain dimethyl tertiary amine as starting materials.The influence of carbon chain length,temperature,surfactant concentration and counter ion on the rheological behavior of aqueous solution of multiple-quaternary ammonium surfactant,and its surface activity were investigated.The critical micelle concentration (cmc) of aqueous solution of the three kinds of synthesized product are 2.0×10^-4,1.0×10^-4 and 8.0×10^-5 mol/L respectively,and γ_cmc values are 39.05,37.45 and 34.12 mN/m respectively.All the cmc and γ_cmc values decrease with the increasing alkyl chain length.The viscosity increasing effect of the multiple-quaternary ammonium surfactant CD3N-18 is remarkable.Viscosity of solution of CD3N-18 increases with the increase of its concentration.Rising of temperature,as well as addition of counter ion will cause increase of viscosity of the solution of the product CD3N-18 firstly and decline later.Counter ion accessory ingredient potassium chloride shows a better viscosity increasing effect while sodium salicylate is helpful for enhancing the temperature resisting property of the product.

Key words: multiple-quaternary ammonium, viscoelastic surfactant, surface activity, rheological behavior