不同酯化度的酯基季铵盐阳离子表面活性剂的制备及性能

SYNTHESIS AND PROPERTIES OF QUATERNARY AMMONIUM SALT CATIONIC SURFACTANT WITH DIFFERENT ESTERIFICATION DEGREE

实验以十二烷基二甲基叔胺(NDT)与环氧氯丙烷(ECH)为原料,合成中间体(2,3-环氧丙基)十二烷基二甲基氯化铵。经正交实验确定的最佳合成条件为:以丙酮为溶剂,反应时间4 h,反应温度30℃,n(NDT):n(ECH)=1:1;再与长链饱和烷基脂肪酸反应,合成不同酯化度的酯基季铵盐阳离子表面活性剂(Ⅰ、Ⅱ)。降解实验结果表明,酯基季铵盐阳离子表面活性剂(Ⅰ、Ⅱ)降解性能优异,降解性随着疏水链的增长而减小,属易生物降解的阳离子表面活性剂。

The intermediate, （2,3-epoxypropyl） dimethyl-ammonium chloride, was synthesized with N,N-dimethyl dodecylamine （NDT） and epichlorohydrin（ECH） as raw materials. Through orthogonally arranged experiments, the optimal preparation conditions were found as follows： with acetone for solvent, n（NDT） ： n（ECH）=1： 1, reaction time 4 h and reaction temperature 30 ℃. The target product quaternary ammonium salt cationic surfactants （Ⅰ and Ⅱ ） with different esterification degree were obtained by reacting the intermediate with lauric acid. Structures of the products were characterized by elemental analysis, infrared spectrum, 1H NMR and 13 C NMR. The critical micelle concentra tions were 8.91×10^-4 and 9.37×10^-4 tool/L, and γemc were 34.12 and 39.76 mN/m for Ⅰ and Ⅱ , respectively. The results showed that the quaternary ammonium salt cationic surfactant with different esterification degrees had excellent surface activity. Degradation testing results showed that the quaternary ammonium salt cationic surfactant （ Ⅰ and Ⅱ ） exhibited excellent degradation performances. Degradable ability decreased with the increase of the hydrophobic proportions.