直链烷基萘磺酸钠的合成及界面活性研究

Synthesis of Long-chain N-Alkylnaphthalene Sulfonates and Study on Their Interfacial Activities

为研究直链烷基萘磺酸盐结构与界面性能的关系,以α-溴化萘为原料,经交叉耦合反应、磺化反应、中和反应等步骤,合成了5种结构明确的直链烷基萘磺酸钠,烷基链的碳数分别为6、8、10、12、14,产物收率50%～60%。用高效液相色谱、质谱、核磁共振氢谱对其进行了色谱纯度、相对分子质量及结构表征,产物色谱纯度均高于96.0%。测量了各烷基萘磺酸钠的NaCl水溶液与正壬烷的界面张力,证实了临界胶束浓度随烷基碳链的增长而减小。

In order to study the relationship between structure and interfacial activity, five long-chain nalkylnaphthalene sulfonates with definite structures were synthesized through three steps including cross-coupling reaction, sulfonation and neutralization, using α-bromonaphthalene as the starting material. The carbon number of the alkyl chain was 6,8,10, 12, 14 respectively. The yields of the sulfonates were 50% -60%. HPLC, MS,^1HNMR were used to characterize the purity, molecular weight,and the structure of the products, of which the purity was all above 96.0%. The interfacial tensions between NaCl aqueous solutions of the naphthalene sulfonates and nonane were measured, showing that the critical micelle concentration decreases with the increase of the carbon number of the alkyl-chain.