Preparation of alkylcyclohexanol polyoxyethylene ether emulsifier and application thereof

A method of preparing an alkylcyclohexanol polyoxyethylene ether (NCEO) emulsifier, wherein the NCEO emulsifier has a structure shown in Formula I as follows:

• Formula I,
• wherein R is a straight-chain or branched alkyl group having a carbon number of C6-C15, and
• wherein n is 5 to 17;
• which comprises:
• conducting an ethoxylation reaction by:
• (a) preparing a catalyst suspension by:
• dissolving KOH as a basic catalyst in water as a solvent at room temperature,
• adding a first amount of NCEO with an adduct number of 1 to 3 (NCEO1-3) in an amount of 20 wt % to 50 wt % of the basic catalyst of the catalyst suspension, wherein the final mass concentration of the basic catalyst is 15 wt % to 25 wt % of the catalyst suspension, and
• stirring the catalyst suspension with sufficient intensity to evenly disperse the first amount of NCEO1-3 in the catalyst suspension,
• wherein:
• the NCEO1-3 has a structural formula shown in Formula II as follows:
• Formula II,
• R is a straight-chain or branched alkyl group having a carbon number of C6-C15,
• n is 1 to 3, and
• the catalyst suspension optionally further comprises at least one of LiOH, K2CO3, or Na2CO3:
• (b) placing the catalyst suspension into a reactor,
• (c) adding a second amount of NCEO1-3 into the reactor with the catalyst suspension, wherein a dry mass of the basic catalyst is 0.1% to 1.0% of a total mass of the NCEO1-3 in the ethoxylation reaction,
• (d) stirring and heating the reactor to a reaction temperature of 90° C. to 140° C.,
• (e) dehydrating the reactor in a vacuum until a water content in the reactor is lower than 0.1%;
• (f) adding ethylene oxide (EO) to the reactor at a molar ratio of NCEO1-3:
• EO of 1:8 while maintaining a system pressure at 0.1 to 0.5 Mpa in the reactor, and maintaining constant reaction temperature,
• (g) stirring the reactor for 0.5 hour to 1 hour after the pressure in the reactor does not drop any more,
• (h) cooling the reactor to room temperature,
• (i) neutralizing the reaction mixture in the reactor by addition of acetic acid to pH 6.5 to 7, and
• (i) discharging the reactor thereby producing NCEO emulsifier.