The Synthesis Of Alkyl Phosphates Ester And Their Properties

This research was mainly focused on the synthesis of a series of Alkyl phosphate ester andon their properties.Firstly, the analytical method of mono-lauryl phosphate ester was studied carefully. It wasfound that the method of potentiometric titration can determine the contents of mono-alkylphosphate ester (MAP), di-alkyl phosphate ester (DAP) and phosphorus acid (PA)simultaneously, and the content of fatty alcohol unreacted can be calculated. Abovepotentiometric titration analysis was confirmed further by gas chromatography. There for, asimple, rapid and more precise method was provided. It is suitable for industrial application.In preparation of MAP, PPA and dodecanol were as raw material. An orthogonalexperimental design with two objective functions was used to optimise the process parameters.The parameters investigated were as follow: temperature, time, PPA density, PPA anddodecanol`s mole ratio. To enhance the ratio of MAP, the best combination of parameters was115% PPA,90℃,0.9:1(mole ratio of dodecanol to PPA),5h, and the product obtained afterhydrolysis (60℃,30min) has the ratio of MAP to 95.8% while the conversion of dodecanol at81.1%. To enhance the conversion of dodecanol, the concentration of PPA was up to 120% andthe other parameters were the same. Then, the conversion of dodecanol reached 95.9% whilethe ratio of MAP down to 88.0%. The product is colorless or light color. Above experimentalresults are comparable with the US patent 5554781. The MAP was characterized by IR and MS.To enhance the content of MAP in products, the methods of purification were tried. It wasfound that the dodecanol residue in product was hard to be removed by vacuumdistillation(25kPa, 122℃). However, by triple washing the ether solution of crude phosphateester with water, 99.8% PA could be removed.The further investigation used ethoxylated fatty alcohol and PPA as raw materials. Thesame factors were investigated even the same result was obtained. The optimal condition was115% PPA,75℃,2h, 2:1(mole ratio of PPA to ethoxylated fatty alcohol) followed by a 2hhydrolysis at 80℃, and the mono-ester ratio arrived at 95.3% while the conversion ofethoxylated fatty alcohol got 95.8%. The product is colorless or light color.We also have exploded the synthesis of DAP with POCl3 and dodecanol as raw materials.The process parameters use the same as above.The optimum condition was 50℃,1:2.1(moleratio of POCl3 to dodecanol),6h esterfization followed by a washing and drying process.Theresearch shows that the yield of DAP was 84.9% while the ratio of DAP was 93.3%.Theproduct is colorless.At last, the phosphate ester was mixed based on MAP and DAP. The properties of surfacetension, foaming and emulsifying ability were measured. DAP has stronger surfactive thanMAP, but MAP and DAP have not synergistic effect. The foaming and emulsifying ability ofMAP is better than DAP.