Study On Synthesis And Solution Properties Of Amino Acid Modified Organosilicon Surfactants

In this paper,two novel amino acid modified trisiloxane surfactant?Si?3?N-AA?and amino acid modified tetrasiloxane surfactant?Si?4?N-AA?were synthesized via a three-step method,and their physicol-chemical properties in solution were investigated.This paper is divided into four parts.The first part,the synthesis and properties of amino acid surfactant and organosilicon surfactant were summarized,and the content of this research was expounded.The second part,amino acid modified trisiloxane surfactant?Si?3?N-AA?was prepared by three-step method,and the final compositions of intermediates and product were characterized by fourier transform infrared spectroscopy?FT-IR?and nuclear magnetic resonance?¹H-NMR?.The result showed that the product was the targeted compound of the research program.The third part,amino acid modified tetrasiloxane surfactant?Si?4?N-AA?was prepared by three-step method,and the final compositions of intermediates and product were characterized by fourier transform infrared spectroscopy?FT-IR?and nuclear magnetic resonance?¹H-NMR?.The result showed that the production was the targeted compounds of the research program.The fouth part,the water-solubility,surface activity and aggregation behavior of Si?3?N-AA and Si?4?N-AA surfactants were investigated by solubility experiment,surface tension measurements,dynamic light scattering?DLS?and transmission electron microscopy?TEM?.The results showed that the Si?3?N-AA and Si?4?N-AA surfactants had good water-solubility;the Si?3?N-AA and Si?4?N-AA surfactants have much higher surface activity than those of conventional hydrocarbon amino acid surfactants,the CMC of Si?3?N-AA and Si?4?N-AA surfactants were 5.2×10^-5 and5.4×10^-6 mol/L,respectively,the?_cmc of Si?3?N-AA and Si?4?N-AA surfactants are22.16 and 20.95 mN/m,respectively;the Si?3?N-AA and Si?4?N-AA surfactants can self-assemble into spherical micelles,average diameters of Si?3?N-AA micelles were in the range from 50 to 300 nm,average diameters of Si?4?N-AA micelles were in the range from 30 to 400 nm.