双十八烷基四羟乙基二溴丙二铵的微波合成及其性能研究

以十八烷基二乙醇胺、1,3-二溴丙烷为主要原料,在微波高压条件下进行季铵化反应合成了一种双子表面活性剂双十八烷基四羟乙基二溴丙二铵（DTDD）,通过红外光谱（IR）和核磁共振（¹H NMR）对DTDD进行了表征,并用液相色谱-质谱联用（LC-MS）测定了其纯度。通过单因素、正交实验得到了微波法合成目标产物的最佳合成条件为：设置微波功率为900 W,反应时间8 h,反应温度为140℃,产品收率达92%以上。与传统加热法对比, 使用微波合成法反应速率大大提高。性能测试结果表明：对比单链季铵盐（OMDAB）,目标产物DTDD具有良好的表面性能,其临界胶束浓度为0.087 g/L,相应的表面张力γ_(CMC)为31.09 mN/m。

Microwave synthesis and properties of dioctadecyl tetrahydroxyethyl dibromopropane diammonium

A gemini surfactant called dioctadecyl tetrahydroxyethyl dibromopropane diammonium (DTDD) was synthesized via quaternization reaction under the condition of microwave and high pressure using octadecyl diethanolamine and 1,3-dibromopropane as the main raw materials. The target compound was characterized by IR and¹H NMR, and its purity was determined by HPLC-ELSD. By analysing the single-factor and orthogonal array design experiments, the optimal synthesis conditions for the synthesis of DTDD by microwave method were determined as follows: microwave power was set to 900W, reaction time was 8h and reaction temperature was 140°C, reaching a yeild of 92%. Compared with the traditional heating method, the reaction rate using microwave synthesis was greatly increased. The critical micelle concentration (CMC), surface tension, Kraft point, and foam properties of the product and the traditional surfactant octadecylmethyldihydroxyethyl ammonium bromide (OMDAB) were determined. The performance test results showed that compared with OMDAB, the target product had good surface properties with the critical micelle concentration of 0.087 g/L and the corresponding surface tension γ_(CMC) of 31.09 mN/m.