Environmentally Friendly Quaternary Ammonium Salt And Performance

With the economic development of our country,the needs of energy sources are growing.Oil extraction is an effective measure widely taken by many countries to improve the oil production. There are many kinds of bacteria in oilfield water injection,which mainly are sulfate-reducing bacteria(SRB),iron bacteria(IB),saprophytic bacteria(TGB).They can make metal corrosion, formation plugging and chemical reagent metamorphism.The most serious corrosion was made by SRB.Now,bactericide is the mainly measure taken widely to control bacteria corrosion. Bis-quatemary ammonium salts is one of the most important bactericide,because of its well bactericidal effects,low toxicity,high water solubility and abroad biological activity.Nitrogenous heterocyclic bactericide have the advantages of good selectivity,high activity,little dosage,low toxicity and the specificity of physiological and biochemical reactions in pest.Besides,with the enhancement of environmental protection consciousness,the serious effect of a lot of chemical reagents,which was used in the oilfield water rejection,on environment is arose much attention.The quaternary ammonium salts with ester group have obvious advantage because of their endemic reducing,security,fast degradation and metabolism.Base on the above investigate background,we synthesis of new types of bis-quatemary ammonium salts contained ester function groups in hydrophobic chain and nitrogen heterocyclic rings,symmetric bis-quatemary ammonium salts containing ester groups(GQ),bis-quaternary ammonium salts containing N-alkyl imidazole and ester groups(GI) and bis-quatemary ammonium salts contained metronidazole and ester groups(GM),which are good of environment.The structures of the above compound were identified by IR,~1HNMR.The krafft point,critical micelle concentration(CMC) of the synthesized bis-quatemary ammonium salts were determined,the corresponding "monomer" surfactants hexadecyltrimethylammonium bromide(CTAB) were used for comparison.The main works are listed as below.(1)Synthesized(2-dodecanoyloxyethyl)dimethylammonio-2-hydroxy-propane chloride.The best reaction conditions were chosen as below:the molar ratio of starting materials:(2-dodecanoylo xyethyl)dimethylamine:(2-dodecanoyloxyethyl)dimethylamine hydrochloride:epichlorohydrin=0.1: 1:1;reaction solvent:isopropanol;reaction temperature:30℃;reaction time:24 h.The final product was yield in 85%.The structure was identified by IR and ~1H NMR.It shows that the pure(2-dodecanoyl-oxyethyl) dimethylammonio-2-hydroxypropane chloride can obtained by controlling conditions.(2)Synthesized 1,3-bis[(2-dodecanoyloxyethyl)dimethylammonio]-2-hydroxy-propane dichloride in aqueous micellar medium.The molar ratio of the starting material:(2-dodecanoyloxyethyl)-dimethylamine: (2-dodecanoyloxyethyl)dimethylamine hydrochloride:epichlorohydrin=1:1:1,reaction temperature:80℃,reaction time:4h.The final product was yield 39%.The advantage of this method was cheaper solvent,shorter reaction time and higher purity.But the reaction yield was more sensitive to the ratio of the starting material,because of the self-micellization phenomenon only occurred over a narrow molar ratio.(3)Synthesized bis-quaternary ammonium salts GI and GM.(2-Dodecanoyloxyethyl) dimethylamine, (2-dodecanoyloxyethyl)dimethylamine hydrochloride,epichlorohydrin and N-alkyl imidazole or metronidazole were used to synthesis of bis-quaternary ammonium salts GI and GM.The structure of final product and were identified by IR.Contents of GM and GI were 87.6%and 85%, respectively.(4)Investigation of the physicochemical properties of bis-quaternary ammonium salts GI and GM.The Krafft point,critical micelle concentration(CMC) and wetting properties of the synthesized bis-quatemary ammonium salts were determined.We found the Krafft points of bis-quaternary ammonium salts GI and GM were both under 0℃,which showed GI and GM had good water-soluble.By studying the CMC,we found the new bis-quaternary ammonium salts GI and GM had high surface activity,because the CMC value of GI and GM was lower than that of CTAB by 2-3 orders of magnitude.But the CMC value of GI and GM was higher than 1,3-bis[(2-dodecan-oyloxyethyl) dimethylammonio]-2-hydroxy-propane dichloride(Ⅱ-12-2).Maybe it was because there was one hydrophobic chain,while there were two inⅡ-12-2.Besides,two inflexion points was observed on the slope of theγ～logC and the inflexion point before the CMC may be induced by association or ionic binding.We found the new bis-quaternary ammonium salts GI and GM had better wetting property than CTBA by the test.By investigating the CMC of the mixed systems GM/SDS and GI/SDS under different mole ratio,we found GI and GM had synergism with SDS in mix micelle system.When the mole ratio of GM or GI to SDS was approximately 1:2,the CMC_T was lower than the CMC of single GM or GI. The effect of decreasing surface tension was not obvious that may be caused by the unequal length chain of GM or GI and SDS in mix micelle.The effects of inorganic salt NaBr on the surface activity of the mixed systems were investigated.NaBr could improve the surface activity of the mixed systems and promote the formation of mixed micelles.With the increasing of the mole ratio of GM/SDS or GI/SDS,the effects of inorganic salt on the surface activity of the mixed systems became smaller.The bactericidal effects of the synthesized quaternary ammonium salts are still studied in our group.