Nonionic Gemini surfactant of (octylphenol polyoxyethylene ether disubstituted) dicarboxylic acid diphenyl ether and its synthesis method

A nonionic Gemini surfactant, (octylphenol polyoxyethylene ether disubstituted) dicarboxylic acid diphenyl ether has a structural formula of: and is prepared by a two-step reaction: S1, diphenyl ether 4,4′-dicarboxylic acid is subjected to an acyl chlorination reaction to obtain diphenyl ether 4,4′-dicarbonyl dichloride; S2, diphenyl ether 4,4′-dicarbonyl dichloride is subjected to an esterification reaction with octylphenol polyoxyethylene ether (OP-10) to obtain the target product (octylphenol polyoxyethylene ether disubstituted) dicarboxylic acid diphenyl ether. The surfactant is expected to be applied in tertiary oil recovery as an alkali/surfactant, in polymer/surfactant binary composite flooding, in alkali/surfactant/polymer ternary composite flooding, as a microemulsion emulsifier and the like, and it can also be compounded with a common surfactant to reduce the use cost, and thus create conditions for its large-scale application.