Synthesis And Performance Measurement Of Dodecyl-phenol Zwitterionic Surfactants Of Betaine Type

In this paper, on the basis of molecular design, we regard dodecyl benzene as raw materials, under the condition of tetrabuty lammonium bromide as phase transfer catalyst,esterification reaction with epichlorohydrin to synthesize intermediates(1) dodecylphenol chlorine ether, then amination reaction with dimethylamine to synthesize intermediates(2)dodecyl phenol tertiary amine, ultimately, the product of dodecyl-phenol zwitterionic surfactants of betaine type were achieved by reacting with the 3-chloro-2-hydroxy propanesulfonate.Effects of salinity, polymer molecular weight, temperature and different medium on the surfactant aqueous solution of C12 BS surface performance were investigated. The results showed that the surface tension of system was increased with the increase of the solution salinity, decreased with the increase of temperature of the system; the surface tension of the system were respectively increased and decreased as the result of polymer and inorganic salt were added.Through the study of the surfactant solution of C12 BS and interfacial properties of Gudao crude oil showed, the oil-water interfacial tension was decreased with the increase of surfactant concentration of C12 BS aqueous solution within a certain range, the concentration rose to some degree, oil-water interfacial tension would not change, when the concentration of the aqueous solution of surfactant C12 SB was 3.0 g/L, the oil-water interfacial tension of Gudao crude oil reached the lowest.The effects of concentration, polymer, salinity, temperature, salt concentration, different kinds of short chain alcohols and propanol concentration on oil-water interfacial tension were investigated. The experimental results showed that the Na+ concentration and Ca2+concentration in a certain range, dynamic interfacial tension between surfactant solution of C12 BS and crude oil reached 10-3mN/m magnitude. Interfacial tension with the aqueous surfactant solution was increased first and then decreased after increase of the concentration of C12 BS aqueous solution, and increased with the increase of salinity, and decreased with the increase of temperature of the system. The addition of short chain alcohol helped decreasing interfacial tension, when the concentration(vol%) of N-propanol in 3%~4% could make the oil-water interfacial tension reaching 10-4 mN/m magnitude. The increase of polymer concentration, increasd the viscosity, decreased first and then increased interfacial tension of the polymer/surfactant binary system and crude oil.The same molecular weight with different concentrations of polymer, the same concentration of polymer with different molecular weight, and temperature affected thesurfactant aqueous solution of C12 BS emulsion properties were investigated respectively. The results showed that with the same molecular weight, increasing polymer concentration, the separation of water of 10 mL required longer time; increasing the molecular weight of polymer, the separation needed more time; increasing temperature of the system, the separation required shorter time.Thermal stability of aqueous surfactant C12 BS and polymer/surfactant system compounded with polymer showed that: under the condition of 85 ℃, the concentration of3.0 g/L surfactant C12 BS in aqueous solution and polymer/surfactant system had good thermal stability, and the interfacial tension of Gudao crude oil was maintained in 10-4mN/m magnitude for 40 days.