一种新型甜菜碱两性表面活性剂的合成及其性能

N,N-二甲基-1,3-丙二胺(1)与丙烯酸甲酯经Michael加成反应制得N,N-二甲基-N′-甲氧酰丙基-1,3-丙二胺(2)； 2经胺基保护、季铵盐化及水解反应合成了一种新型的甜菜碱两性表面活性剂(6)，其结构经¹H NMR, IR和ESI-MS表征。通过电导率法测得6的CMC为1.48×10^-4mol·L^-1，滴体积法测得γ_CMC为39.99 mN·m^-1， Krafft点小于0 ℃。乳化与泡沫性能研究结果表明：6具有较好的表面活性，且乳化性和泡沫性能优良。

Synthesis and Properties of A Novel Amphoteric Betaine Surfactant

N,N-dimethyl-N′-(acyl-methoxy-propyl)-1,3-propanediamine(2) was prepared by reaction of N,N-dimethyl-1,3-propanediamine with methyl acrylate. A novel amphoteric betaine surfactant(6) was obtained by amino protection， quaterisation and hydrolysis from 2. The structure was characterized by ¹H NMR, IR and ESI-MS. The surface properties of 6 were investigated. The results showed that the critical micelle concentration(CMC) was 1.48×10^-4 mol·L^-1, the surface tension(γ_CMC) was 39.99 mN·m^-1, and the Krafft point was below 0 ℃. Moreover, 6 exhibited good surface activities, excellent emulsifying capacity and forming capacity.