CN100338019C - Lauryl alcohol polyethylene glycol oxide ester benzoic ether and its synthesis - Google Patents

Abstract

The invention discloses a lauryl alcohol polyoxyethylene ether benzoate and a synthesis method thereof. The method utilizes lauryl alcohol polyoxyethylene to carry out esterification reaction with benzoyl chloride under a solvent-free condition. The process conditions are as follows: raw material ratio The ratio is 1:1.05～1.20, the reaction temperature is 85～90°C, the reaction time is 3-4 hours, the reaction product is washed twice with 5% sodium carbonate solution, dried, and the lauryl alcohol polyoxyethylene ether benzoate is obtained by detection and analysis. product. The lauryl alcohol polyoxyethylene ether used in the present invention is an organic raw material commonly used in industry, and has abundant reserves. The obtained lauryl alcohol polyoxyethylene ether benzoate is an alcohol-based nonionic surfactant, and the product has special oil removal ability And excellent wettability, compatible with anionic and cationic surfactants, so that it has a wide range of application prospects.

Description

A kind of polyoxyethylene lauryl ether benzoate and its synthetic method

technical field

The invention relates to an alcohol-based nonionic surfactant, more specifically to a lauryl alcohol polyoxyethylene ether benzoate surfactant, and belongs to the technical field of organic chemical additives.

Background technique

With the advent of the 21st century, the sustainable development of society and its related ecological, environmental, resource, economic and other issues have increasingly become the focus of attention of the international community and have been raised to the height of development strategy. What is more serious is the requirement of environmental protection, prompting the chemical industry to focus on eliminating or reducing the generation of waste from the source, that is, the prevention of original pollution, rather than the treatment after pollution. Many of today's chemical products and their production processes are mostly developed on the basis of the technology of the 1950s. While making contributions to human's food, clothing, housing, transportation and medical care, they also have many adverse effects on the natural environment. . This inevitably puts forward new requirements for science and technology, poses challenges to chemistry, especially synthetic chemistry, and also provides opportunities for discipline development. In recent years, green chemistry, environmentally mild chemistry, clean technology, and environmentally friendly processes have become hot topics, and the environment and economy are becoming the main driving forces for technological innovation.

The surfactant industry is a chemical industry developed in the 1930s. With the development of the petrochemical industry, the output of surfactants has increased rapidly and has become one of the basic industries of the national economy. At present, there are more than 5,000 types of surfactants in foreign countries, more than 100 types of commercial brands, and the total output has exceeded 10 million tons. Among them, the growth rate of nonionic surfactants is 1%/, while the growth rate of alcohol-based nonionic surfactants is more than 5%.

my country's surfactant industry is currently in the development stage, and scientific research, production, application, and development are all valued by relevant departments. With the development of my country's economy and petroleum industry, the application fields of domestic surfactants are gradually expanding, and the status of surfactants in the national economy is also increasing. The development and application of alcohol-based nonionic surfactants is more important. People such as Gao Lixin in China once reported that a kind of surfactant was synthesized as a solvent using _CCl4 -lauryl alcohol polyoxyethylene ether phosphate (published in the 5th issue, the 30th volume, Daily Chemical Industry Magazine, No. 63-66 in 2000 Page). This reaction is carried out in the organic solvent CCl ₄ , and the reaction process will not only bring harm to the environment, but also waste resources and energy. Because the amount of conventional organic reaction solvent is generally 50-100 times the amount of raw materials, without any solvent, avoiding the use of a large number of toxic and volatile organic compounds, not only reduces pollution, simplifies the reaction operation and post-treatment process, shortens The reaction time is shortened, the production cost is reduced, and it has the advantages of high yield and strong selectivity, so this kind of organic reaction has become an important way to realize "green chemistry".

Purpose of the present invention is exactly in order to overcome above-mentioned deficiencies in the prior art, and proposes to synthesize a kind of substantially nontoxic under solvent-free conditions, the alcohol-based nonionic surfactant of pollution-free polyoxyethylene lauryl ether benzoate new New technology for solvent-free synthesis of products. This kind of surfactant not only has potential broad prospects in industrial application, but also has innovations in synthesis methodology.

Contents of the invention

The purpose of the present invention is achieved through the following technical solutions.

Lauryl alcohol polyoxyethylene ether benzoate is a non-toxic, non-polluting alcohol-based nonionic surfactant,

Its molecular structure is

or written as

General nonionic surfactant molecules have an asymmetric amphiphilic structure, that is, one end of the molecule is lipophilic and the other end is hydrophilic. Lauryl polyoxyethylene ether benzoate is lipophilic at both ends and hydrophilic at the middle, and the hydrophilic group in the molecule is a polyoxyethylene ether chain, namely (OCH ₂ CH ₂ ) _n OH. The oxygen atoms and hydroxyl groups in the chain have the ability to form hydrogen bonds with water molecules, which makes the compound have some special properties. It is a special alcohol-based nonionic surfactant.

The product has an acid value mgKOH/g≤10, an ester content (%)≥95, and a refractive index (20°C) of 1.471-1.477.

The step of polyoxyethylene lauryl ether benzoate synthetic method is as follows:

First put a certain amount of polyoxyethylene lauryl ether into a heating container, and stop heating when the temperature rises to 55-60°C; then slowly add a certain amount of benzoyl chloride dropwise to the lauryl In the heating container of alcohol polyoxyethylene ether, stir while adding, after the dropwise addition, continue to heat up to 85-90°C, and esterify for 3-4 hours; stop the reaction, cool to room temperature, and stand still; Add 5% sodium carbonate solution to the container of the reaction product to wash for the first time, and let it stand; Analysis concludes with product characterization.

The invention uses lauryl alcohol polyoxyethylene ether as a raw material to carry out substitution reaction with benzoyl chloride under solvent-free conditions. The reaction itself is an esterification reaction and is a reversible reaction. In order to carry out the reaction to the end and improve the reaction yield, the ratio of raw materials is very important. If benzoyl chloride is used in excess, the reaction will proceed in the positive direction, but the problem is that benzoyl chloride is easy to sublimate and decompose.

The generated benzoic acid is slightly soluble in water. If there is too much benzoyl chloride, it will bring many difficulties to the aftertreatment of the product. After repeated tests, the molar ratio of polyoxyethylene lauryl ether to benzoyl chloride is preferably 1:1.05-1.20. A small amount of benzoic acid generated in the reaction system can be sublimated to the wall of the vacuum tube to crystallize and be removed when the temperature rises to 100°C. The HCL generated by the reaction is absorbed by the hydrochloric acid absorber, so no pollutants are generated during the reaction process.

Lauryl alcohol polyoxyethylene ether and benzoyl chloride can react at room temperature, and the product is almost colorless. However, it needs to react for more than 24 hours at normal temperature, and the conversion rate is only below 80%. In order to increase the reaction speed and shorten the reaction time, we adopt the method of heating under normal pressure in order to shorten the reaction time and achieve a higher conversion rate. The test proves that the reaction at 85-90° C. under normal pressure for 3-4 hours can achieve a yield of 95%.

The heating vessel of the present invention can be a four-necked flask or a round-bottomed flask with a mouth equipped with a stirrer, a thermometer, and a condenser, and the heating method can be an oil bath or electric heating or other heating methods.

Compared with the prior art, the present invention has the following advantages and properties:

(1) It has excellent oil solubility and can be miscible with crude oil, diesel oil, kerosene, engine oil, lubricating oil, vegetable oil, etc. in any proportion;

(2) Miscible with various organic solvents;

(3) No foam, both anti-foaming and defoaming properties;

(4) Compatible and compatible with anionic, cationic, nonionic, and zwitterionic surfactants, and can be synergistic;

(5) It has dispersing, wetting, penetrating, solubilizing and antistatic properties, and is stable in acidic and alkaline solutions;

(6) Mild, safe and non-irritating, it has a protective effect on skin, clothing, machines and various metal surfaces.

Description of drawings

Fig. 1 is a block diagram of the process flow of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figure 1, first put a certain amount of polyoxyethylene lauryl ether into a round bottom flask, then place the round bottom flask in an oil bath heater, heat up to raise the temperature in the flask to 55-60 °C , stop heating, then slowly drop a certain amount of benzoyl chloride into the round-bottomed flask according to the proportion, and stir while adding. To 85 ~ 90 ℃, esterification reaction for 3-4 hours, stop the reaction, cool to room temperature, stand still, add 5% sodium carbonate solution to wash twice, after standing, put the reaction product in a desiccator to dry, after testing Analyze the final product.

Example 1:

Put the measured 1mmol lauryl polyoxyethylene ether (n=9) into a 50ml round bottom flask, then place the flask in an oil bath heater to heat, and add the measured 1.00mmol benzoyl chloride to the constant pressure drop In the funnel, when the temperature in the flask rises to 55-60°C, stop heating, turn on the agitator, and slowly add benzoyl chloride dropwise; after the dropwise addition, raise the heating temperature to 85-90°C, and react for 3-4 hours , stop stirring, let stand.

Example 2:

Put the metered 1mmol of polyoxyethylene lauryl ether (n=9) into a 50ml round bottom flask, then place the flask in an oil bath heater to heat, and add the metered 1.05mmol of benzoyl chloride to the constant pressure drop In the funnel, when the temperature in the flask rises to 55-60°C, stop heating, turn on the agitator, and slowly add benzoyl chloride dropwise; after the dropwise addition, raise the heating temperature to 85-90°C, and react for 3-4 hours , stop stirring, let stand.

Example 3:

Put the metered 1mmol lauryl polyoxyethylene ether (n=9) into a 50ml round bottom flask, then place the flask in an oil bath heater to heat, and add the metered 1.20mmol benzoyl chloride to the constant pressure drop In the funnel, when the temperature in the flask rises to 55-60°C, stop heating, start the agitator and slowly add benzoyl chloride dropwise; after the dropwise addition, raise the heating temperature to 85-90°C, and react for 3-4 hours. Stop stirring and let stand.

Example 4:

Put the metered 1mmol lauryl polyoxyethylene ether (n=9) into a 50ml round bottom flask, then place the flask in an oil bath heater to heat, and add the metered 1.30mmol benzoyl chloride to the constant pressure drop In the funnel, when the temperature in the flask rises to 55-60°C, stop heating, start the stirrer and slowly add benzoic acid chlorine dropwise; after the dropwise addition, raise the heating temperature to 85-90°C, and react for 3-4 hours Stop stirring and let stand.

After above-mentioned embodiment 1-4 reaction finishes, use refractometer to measure the refractive index of reaction product, judge whether the degree of esterification reaction is good according to refractive index; The rate is about 1.4730. After meeting the requirements, the reaction product needs to be washed twice with 5% sodium carbonate solution, left to stand, dried, and the acid value of the measured product is about 1.043mgKOH/g. If the acid value is below 10mgKOH/g, then The conversion rate of this reaction is above 95%, which has reached the expected goal.

The evaluation indicators of the obtained products are as follows:

Appearance: light yellow transparent liquid

Color≤180

Acid value (mgKOH/g)≤10

Ester content (%)≥95

Refractive index (20°C) 1.471～1.477

The nuclear magnetic data of gained product is as follows:

¹ H NMR (400MHz, CDCl ₃ ), δ=8.07-7.42(m, 5H, Ph-H), 4.91-4.47(m, 2H), 3.85-3.43(m, 36H), 1.76(s, 2H), 1.59-1.55 (m, 2H), 1.25 (s, 16H), 0.90-0.86 (m, 3H). Infrared analysis is as follows: IR (ν/cm ^-1 ): 2924, 2855, 1720, 1453, 1275, 1111, 950, 714. It can be seen from the nuclear magnetic resonance data that there are two hydrogens in the chemical shift of 4.91-4.47ppm, which are hydrogens on the methylene of PhCOOCH ₂ -, indicating that lauryl alcohol polyoxyethylene ether reacts with benzoyl chloride . In addition, this point can also be explained from the infrared data. There is a strong absorption peak at 1275cm ^-1 , indicating the existence of an ester group. This point can also be explained from other absorption peaks.

Claims (3)

1. a polyoxyethylene lauryl ether benzoate, is characterized in that: molecular structure is

or written as

The acid value is about 1.043mgKOH/g, the refractive index is about 1.4730, and the ester content is ≥95%. 2. a kind of synthetic method of lauryl alcohol polyoxyethylene ether benzoate as claimed in claim 1 is characterized in that: first lauryl alcohol polyoxyethylene ether is dropped into a heating vessel and heated up to At 55-60°C, stop heating; then slowly add benzoyl chloride dropwise into the heating container according to the proportion of raw materials, and stir while adding, after the dropwise addition, continue heating to 85-90°C, esterification reaction 3 4 hours; stop the reaction, cool to room temperature, and stand still; add 5% sodium carbonate solution to the heating container containing the reaction product for the first washing, and let stand; then add 5% sodium carbonate solution for the second time Washing, standing still, drying the reaction product in a desiccator, and finally characterizing the product after detection and analysis, the raw material ratio of the lauryl alcohol polyoxyethylene ether and benzoyl chloride is: 1:1.05-1.20. 3. the synthetic method of a kind of polyoxyethylene lauryl ether benzoate according to claim 2, is characterized in that: described heating vessel can be the four-necked flask that agitator, thermometer, condensation pipe are housed or Round bottom flask with mouth, heating method can be oil bath or electric heating.

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