Synthesis And Application Study Of Surfactants With Scale Inhibition Effect

Different octyphenol polyoxyehtylene ether phosphate (OPP) surfactants were synthesized by phosphorylation using polyphosphoric acid (PPA) and POCl3. For PPA used as phosphorylation reagent,the optimal synthesis conditions were obtained as follows: the molar ratio of PPA to OP-4 1.6, esterification temperature 110~120℃and time 6~8h, the volume of hydrolysis 5%, hydrolization temperature 120℃and time 2.5~3.5h. All the products synthesised were monoester with the content of more than 93%. For POCl3 used as phosphorylation reagent, the optimal synthesis conditions were obtained as follows: molar ratio of POCl3 to OP-4 1.2, esterification temperature 40~50℃, hydrolysis fraction 10%, hydrolysis temperature 60℃hydrolysis time 3~4h. The synthetic products were all the mixtures of monoester and Diester, of which the highest level of monoester could reach more than 87%, with the content of Diester about 3% and the yield of esterification more than 90%.Synthesized three kinds of lamineo dimethylene phosphonic acids and two kinds of phosphobetain surfactants: dodecylamineo dimethylene phosphonic acid (DAMP), octadecylamino dimethylene phosphonic acid (OAMP) , dioctylamino methylene phosphonic acid (DOAMP), N, N-dimethy-tridecane hydroxyethyl ammonium phosphate, N, N-dimethylethanolamine (PBET-13), N, N-dimethy-heptadecane hydroxyethyl ammonium phosphate,N,N-dimethylethanolamine(PBET-17). DAMP optimal synthesis conditions was determined as follows: the molar ratio of formaldehyde to dodecylamine 2.5, the molar ratio of phosphorous acid to dodecylamine 3.5, reaction temperature 105℃, reaction time 3.5h, water volume 15mL, the amount of hydrochloric acid 5mL, the organophosphorus yield of DAMP synthesized under Under these conditions are more than 85%. In the concentration of 10mg/L,the CaSO4 scale inhibition ratio of DAMP and OAMP have reached 97.4% and 92.1%, single lamineo dimethylene phosphonic acids or phosphobetain surfactants have ordinary interfacial activity,the dynamic IFT of crude oil-water system,with the mixture of appropriate concentration of NaCl and NaOH,could be reach to the ultra-low value of less than 10-3mN?m-1.