新型腰果酚双子表面活性剂的合成及表面活性

以天然生物质腰果酚、1,3-二溴丙烷及氯磺酸为原料,通过醚化、磺化及中和三步反应合成了一类新型的腰果酚基磺酸盐双子(Gemini)表面活性剂.采用傅立叶转换红外光谱仪和核磁共振谱仪表征了产物的结构;采用滴体积法测定了腰果酚Gemini表面活性剂的表面张力,研究了水溶液的表面性质,并与相应的单基腰果酚基磺酸盐表面活性剂进行了对比.结果表明:腰果酚Gemini表面活性剂水溶液的临界胶束浓度(cmc)为6.20×10-2 mmol.L-1,远小于相应的单基腰果酚表面活性剂水溶液的cmc(8.40mmol.L-1);其临界表面张力γcmc为36.92mN.m-1,与单基腰果酚表面活性剂水溶液的相近(γcmc为38.41mN.m-1).与此同时,腰果酚Gemini表面活性剂水溶液的最小分子截面积Amin为0.27nm2,比相应的单基表面活性剂水溶液的小得多.

Synthesis and surface activity of a novel cashew-based gemini surfactant

A cashew-based Gemini surfactant was synthesized from cashew phenol,1,3-dibromopropane and chlorosulfonic acid through etherification,sulfonation and neutralization.The structure of as-synthesized cashew-based Gemini surfactant was confirmed by Fourier transform infrared spectrometry and nuclear magnetic resonance spectroscopy.The surface tension and critical micelle concentration（cmc） of the cashew-based Gemini surfactant in aqueous solution were measured with drop volume method,and the surface activity of the cashew-based Gemini surfactant solution was compared with that of corresponding monomeric cashew-based surfactant solution.Results show that the cmc for the cashew-based Gemini surfactant in aqueous solution is 6.2×10-2 mmol·L-1,much smaller than that of corresponding monomeric cashew-based surfactant（cmc=8.40 mmol·L-1）.The surface tension of the aqueous solution of as-synthesized cashew-based Gemini surfactant is γcmc=36.92 mN·m-1,which is similar to that of the aqueous solution of corresponding monomeric cashew-based surfactant（γcmc=38.41 mN·m-1）.Besides,the aqueous solution of as-synthesized cashew-based Gemini surfactant has a minimum molecular cross-sectional area of Amin=0.27 nm2,which is much smaller than that of the aqueous solution of corresponding monomeric cashew-based one.