含酯基不对称双季铵盐表面活性剂的合成

以长链烷基叔胺、盐酸、环氧氯丙烷为原料,合成了N (3 氯 2 羟丙基) N,N 二甲基长链烷基氯化铵,研究了其合成工艺,优化反应条件为:n(长链烷基叔胺)∶n(盐酸)∶n(环氧氯丙烷)=1∶1∶1 1,反应温度为40℃,体系pH=6～7。以月桂酸及2 二甲氨基乙醇为原料,酯化得到二甲基月桂酸乙基叔胺(Ⅲ),利用其与N (3 氯 2 羟丙基) N,N 二甲基长链烷基氯化铵季铵化得到含酯基不对称双季铵盐阳离子表面活性剂〔长链烷基分别为(Ⅰ)C12H25和(Ⅱ)C14H29〕。经测定,产物的临界胶束浓度CMC分别为6 61×10-3、8 31×10-3mol·L-1,γCMC分别为37 6、39 2mN·m-1,证明所合成的含酯基不对称双季铵盐阳离子表面活性剂具有较高的表面活性。

Synthesis of Dissymmetric Bis-quaternary Ammonium Salt Surfactant with Ester Bond

N-(3-Chloro-2-hydroxypropyl)-N,N-dimethylakylammonium chloride〔(Ⅰ):alkyl=C_(12)H_(25),or(Ⅱ):alkyl=C_(14)H_(29)〕 was prepared with N,N-dimethylakylamine,hydrochloric acid and epichlorohydrin.The optimum reaction conditions were n(N,N-dimethylakylamine)∶n(hydrochloric acid)∶n(epichlorohydrin)=1∶1∶1.1,reaction temperature 40 ℃ and pH value of the system 6～7.N,N-Dimethylethylamine with ester bond(Ⅲ) was prepared with lauric acid and 2-dimethylaminoethanol.Surfactant was synthesized with Ⅰand Ⅲ or Ⅱ and Ⅲ.CMC of the two surfactants were 6.61×10~(-3) and 8.31×10~(-3) mol·L~(-1) and γ_(CMC) of them were 37.6 and 39.2 mN·m~(-1) respectively.The results show that the dissymmetric bis-quaternary ammonium salt cationic surfactants have excellent surface activity.