[Background and Overview][1][2]
Phosphate ester surfactant is a kind of surfactant with excellent performance and wide application. It is generally composed of monoalkyl phosphate, dialkyl phosphate and other ingredients. The antistatic properties, foaming properties, water solubility, and emulsification properties of monoalkyl phosphates are better than those of dialkyl phosphates, and their irritation to the skin is less than that of anionic surfactants such as alkyl sulfonates and alkyl sulfates. Due to the wide range of uses of monoesters, it is very necessary to increase the mass fraction of monoesters in products to meet the needs of surfactants in various sectors of the national economy. In recent years, due to its wide range of uses, it has developed rapidly and has a wide variety of varieties, and new varieties are constantly being developed. After the anionic active agent relay alkyl sulfate and sulfonate, alkyl phosphate has quickly become an anionic active agent. Big series.
Potassium monododecylphosphate (MAPK) is a very important anionic surfactant with the characteristics of alkyl phosphate: ① low toxicity; ② low irritation; ③ significant biodegradability ; ④ Good mutual solubility when combined with other agricultural surfactants; ⑤ Wide range of solubility with water; ⑥ Good acid, alkali and electrolyte resistance; ⑦ Good temperature resistance; ⑧ Lower surface tension and better Excellent water wettability; ⑨ Outstanding antistatic properties to chemical fiber fabrics; ⑩ Special lubricity to metal surfaces. It is not only an indispensable additive in metal lubricants, synthetic resins, paper pulp, pesticide detergents, and cosmetics, but its many special properties are also utilized in the textile printing and dyeing, and fiber processing industries. Because phosphate esters are structurally and physiologically similar to natural lecithin, they are less toxic and less irritating than other surfactants and have been widely used in personal protective products in recent years.
[Performance Study][1][2]
1. Research on frost resistance:
1) Free alcohol: The content of free alcohol has a great influence on the frost resistance of potassium monododecyl phosphate. When the concentration, free acid and pH value of monododecylphosphate potassium salt are constant, the freezing resistance of monododecylphosphate potassium salt decreases significantly with the increase of free alcohol. When the content of free alcohol is 1.5%, the turbidity of the system increases significantly, that is, the frost resistance of monododecylphosphate potassium salt decreases significantly. This shows that the free alcohol content of 1.5% is a sensitive limit value. Below this value, the salt solution system has higher frost resistance, and above this value, the salt solution system has lower frost resistance.
2) Free acid: The pH value has a phased effect on the frost resistance of potassium monododecyl phosphate: when the pH value is 6 to 8, the frost resistance of potassium monododecyl phosphate shows an increasing trend; When the pH value is 8 to 9, the frost resistance of potassium monododecyl phosphate shows a downward trend.
3) Water hardness: The impact of water hardness on the frost resistance of potassium monododecyl phosphate is relatively large. The frost resistance decreases significantly as the water hardness increases. Because water contains a lot of Mg2+ and Ca2+, and calcium monododecyl phosphate and magnesium monododecyl phosphate are both insoluble. Of water. According to the principle of thermodynamics, if there are Mg2+ and Ca2+ in the system, it is easy to generate calcium monododecyl phosphate and monododecyl phosphate. magnesium, thereby reducing the frost resistance of potassium monolauryl phosphate.
2. Antistatic research: The antistatic properties of dodecyl phosphate monoester were studied according to the method in GB/T 16801-1997. The potassium salt, sodium salt and tri-dodecyl phosphate monoester were investigated. The antistatic properties of ethanolamine salts and unneutralized phosphate monoesters on polyester fabrics. The results show that potassium salts and unneutralized phosphate monoesters have better antistatic effects on polyester fabrics. After determining the conditions for using potassium salt and unneutralized phosphate monoester as antistatic agents, the effect of their mass concentrations on the antistatic properties of polyester cloth was investigated. The results showed that when the mass concentration of potassium monoester salt was 4g /L, when the monoester is 6g/L, the antistatic performance of polyester cloth is better. When the mass concentration of monoester potassium salt was 4 g/L and the monoester was 6 g/L, their antistatic effects on polyester cloth, cotton cloth and acrylic cloth were investigated. The results showed that their antistatic effect on acrylic cloth was Both are better than the other 2 kinds of cloth.
[Production process][3]
Use polyphosphoric acid and phosphorus pentoxide as a phosphorylation reagent to react with alcohol to synthesize monoalkyl phosphates. The chemical reaction is:
Add a certain amount of polyphosphoric acid to a three-necked flask equipped with a stirrer. Add a certain excess of n-dodecanol at 50 to 70°C, then control the temperature under stirring conditions and stir until the solution is uniform. , then add a certain amount of phosphorus pentoxide, adjust the temperature to 70~90°C under stirring conditions, and react to the specified time. In the above reaction, the phosphorylation reagent is composed of polyphosphoric acid and phosphorus pentoxide. The molar ratio of phosphorylation reagent to alcohol is 1:1. After the reaction, add a certain amount of deionized water, stir the hydrolysis reaction for the specified time, and cool to The material is discharged at about 60℃. Under process conditions such as the reaction temperature of the phosphorylation reagent and dodecanol is 80°C, the reaction time is 5 h, the molar ratio of polyphosphoric acid and phosphorus pentoxide added is 1:1, and the mass fraction of polyphosphoric acid is 110%, the monoalkyl The mass fraction of base phosphate plastic antibacterial agent is 78.77%, the mass fraction of dialkyl phosphate is 14.02%, the mass fraction of phosphoric acid is 3.34%, and the conversion rate of dodecanol is 98.67%.
[Application][4]
1. Daily chemical industry
1) Detergent: Phosphate ester surfactants can be used as industrial cleaning agents, fabric antistatic agents, liquid transparent detergents and dry cleaning detergents. Due to its high price, detergent phosphate esters are not used as detergents alone, but are used only as detergent components. The advantages are that it is stable against strong alkaline components without discoloration, has excellent dust removal performance, is soluble in high-concentration and high-temperature solutions of other components, has good washing and decontamination properties, moderate foaming properties, and very low skin irritation. . Therefore, phosphate esters have become an important component in detergent formulas and are used in formulas of heavy-duty detergents, various hard surface cleaners, such as metal cleaners, floor cleaners, ship cleaners and various civil cleaners.
2) Penetrating agent: Phosphate ester has good stability and solubility in alkaline solution, and its wetting effect has nothing to do with the solution value. An excellent alkali-resistant penetrating agent can be prepared by selecting appropriate hydrophobic groups for necessary ethoxylation and then phosphorylating with phosphorylating reagents. Phosphate esters have better wetting properties than nonionic surfactants in alkaline solutions.
3) Antistatic agent: Phosphate ester is used in many aspects as an antistatic agent. It can be used in aqueous solution systems and hydrophobic systems.
2. Composition of chemical fiber oils: Alkyl phosphates are widely used in chemical fiber oils. Whether it is polyester, nylon, nylon, vinylon, chlorine fiber, polypropylene, etc., or filament or short filament, phosphate ester is inseparable from the component of oil formulations at home and abroad. The phosphate esters used are also varied, and each one chooses what it needs. For example, the nylon oil agent uses monoalkyl phosphate ester salt, and the nylon oil agent uses sodium octyl ether phosphate, etc.
3. Cosmetics and pharmaceutical industry
Phosphorus-containing surfactants can be used as solubilizers for transparent jelly cosmetics and emulsifiers for skin care creams and skin care lotions. In the production of medical cosmetics, in order to improve the solubility of medicinal ingredients and fragrances, certain solubilizers must be added. Alkyl phosphates have low toxicity, are acid-resistant, alkali-resistant, bacteria-resistant, hydrophilic, and lipophilic, and are easily metabolized by organisms. They are a widely used solubilizer series. Certain phosphate ester industrial additives have anti-cancer and anti-tumor activity, and dozens of drugs have been developed.
4. Pesticide and paper industry
Phosphate ester surfactants have strong emulsifying power, good stability, and low foaming properties. They are excellent at emulsifying pesticides. They can not only be antibacterial and insecticidal, but can also be used as herbicides. In the papermaking industry, it can be used as a deinking agent for waste paper and a dispersion stabilizer for coated paper and coating liquids.
5. Plastic leather industry
As a new type of product, phosphate-based leather fatliquor has become one of the current research hotspots in leather chemicals due to its excellent application performance and easy biodegradability.
[References]
[1] Tang Kai, Yan Jie, Huang Xin, et al. Research on the freeze resistance of potassium monododecylphosphate solution[J]. Chemical Intermediates, 2008 (8): 39-41.
[2] Shi Yaning, Zhao Yonghong, Zhang Guangliang, et al. Research on the antistatic properties of dodecyl phosphate monoester [J]. Daily Chemical Industry, 2018, 48(1): 23-26.
[3] Li Xuming, Yan Jie, Tang Kai, et al. Research on the synthesis process of monododecyl phosphate [J]. Journal of Yunnan University: Natural Science Edition, 2008 (S2).
[4] Ba Yan. Synthesis and surface properties of alkyl phosphates[D]. Dalian University of Technology, 2005.
