阳离子表面活性单体DMOHAC的合成及其胶束化行为

摘要

以环氧氯丙烷、丙烯酰胺及N,N-二甲基十八烷基叔胺为原料,经开环和季铵化两步反应合成了新型阳离子表面活性单体,N,N-二甲基十八烷基(2-羟基-3-丙烯酰胺丙基)氯化铵(DMOHAC,1),其结构经FT-IR表征。用TG和摩尔电导率法研究了1的热稳定性和1、十八烷基三甲基氯化铵( OTAC)、1/OTAC混合胶束的CMC值。结果表明：1的热稳定性能良好,1和 OTAC 的 CMC 值分别为0.10 mmol · L-1和0.33 mmol · L-1。当n(1)∶n(OTAC)=2∶1时,1/OTAC混合胶束的CMC值为0.12 mmol·L-1；当n(1)∶n(OTAC)=1∶2时,1/OTAC混合胶束的CMC值为0.21 mmol·L-1。1/OTAC混合胶束的CMC值介于1和OTAC之间。%A novel cationic surface-active monomer, dimethyl octadecylalkyl ( 2-hydroxyl-3-acrylami-dopropyl) ammoniumchloride(DMOHAC, 1), was synthesized using epichlorohydrin, acrylamide and N, N-dimethyloctadecylamine as materials through opening-ring and quaternization reactions. The structure was characterized by FT-IR, and the thermal stability of 1 was studied by thermogravimetric analysis. The critical micelle concentration(CMC) values of 1, octadecyl trimethyl ammonium chloride ( OTAC) and 1/OTAC mixed micelles were measured respectively using molar conductivity method. It was found that 1 exhibited pronounced thermal stability. The CMC values of 1 and OTAC were 0. 10 mmol·L-1 and 0. 33 mmol·L-1 , respectively. The CMC values of 1/OTAC mixed micelles were 0. 12 mmol·L-1and 0. 21 mmol·L-1 when the ratio of n(1) ∶n(OTAC) was 2∶1 and 1∶2 respective-ly. The results showed that the CMC value of 1/OTAC mixed micelles was between 1 and OTAC.