Synthesis method of fumaric acid modified nonionic surfactant

Abstract

The invention provides a synthesis method of a fumaric acid modified nonionic surfactant, which comprises the following steps: placing BASF fatty alcohol-polyoxyethylene ether in a dry reaction bottle, and then adding fumaric anhydride; oxygen removal and low-temperature dissolution: introducing nitrogen into the reaction bottle for thorough purging so as to completely remove air in a reaction system, sealing the reaction bottle after purging is completed, and heating the sealed reaction bottle in an oil bath pan so as to completely dissolve fumaric anhydride to obtain a mixed solution; catalytic grafting reaction: adding a catalyst into the mixed solution, then gradually heating and continuously stirring, in the reaction process, monitoring the reaction progress in real time through a nuclear magnetic resonance hydrogen spectrum, and judging that the reaction is completed when monitoring that a fumaric acid double-bond characteristic peak disappears and a maleic acid double-bond characteristic peak appears, so as to obtain a reaction mixture; product post-treatment: cooling the reaction mixture to room temperature, standing, removing white precipitate, and collecting residual liquid, namely a crude product of grafted fumaric acid; and determining the grafting rate.

Description

A method for synthesizing fumaric acid-modified nonionic surfactants Technical Field

[0001] This invention relates to the field of piezoelectric ceramic inkjet technology, and in particular to a method for synthesizing a fumaric acid-modified nonionic surfactant. Background Technology

[0002] In piezoelectric ceramic inkjet technology, slurry viscosity is a crucial physical property of inkjet inks. To achieve good dispersion stability and anti-settling properties in low-viscosity systems without significantly increasing the system viscosity, and to ensure compatibility with other slurry components, nonionic surfactants are generally recommended. Nonionic surfactants exhibit strong stability in alkaline, high-ionic-strength sodium carbonate slurries and are not affected by electrolytes (Na+). + CO3² - Salting out occurs due to the presence of [a substance], and its hydrophilic groups (polyoxyethylene chains) are dispersed through hydrogen bonding, having minimal impact on the viscosity of the system, making it suitable for low-viscosity slurries.

[0003] Fatty alcohol polyoxyethylene ethers, abbreviated as AEO, are among the most common nonionic surfactants. They possess excellent emulsifying properties, forming stable emulsions between aqueous and oil phases, allowing oily components to be uniformly dispersed in water. They are used in the preparation of emulsion-type cosmetics, pharmaceuticals, pesticides, etc. They can also effectively disperse solid particles or droplets in a medium, making them suitable for preparing suspending agents, pigment dispersants, etc.

[0004] However, due to the inherent mismatch between the surface characteristics of sodium carbonate particles and the adsorption requirements of AEO, the following problems exist: 1. Surface characteristics of sodium carbonate particles: Sodium carbonate is an ionic compound, and the particle surface exposes bare, charged CO3²⁻. - and Na + 1. AEO lacks covalently bonded polar functional groups (such as -OH, -COOH), possessing only ionic bonds and electrostatic interactions. Its surface is dominated by strong electrostatic interactions and lacks "active sites" to form hydrogen bonds with the polar ends of AEO. 2. Adsorption characteristics of AEO: The polar end of AEO is a polyoxyethylene chain (-OCH2CH2-), which achieves adsorption by forming hydrogen bonds with other molecules through the oxygen atoms in the ether bond; the non-polar end is a hydrophobic alkyl chain, used to provide steric hindrance. AEO adsorption requires the presence of polar groups on the surface capable of forming hydrogen bonds (such as -OH, -COO). - Sodium carbonate particles, however, lack such sites on their surface and can only generate weak ion-dipole interactions, making stable adsorption impossible. Summary of the Invention

[0005] The purpose of this invention is to provide a method for synthesizing a fumaric acid-modified nonionic surfactant that provides a strong polar anchoring point for AEO, thereby achieving stable adsorption of AEO on the surface of sodium carbonate particles.

[0006] To solve the above-mentioned technical problems, this invention provides a method for synthesizing fumaric acid-modified nonionic surfactants, comprising the following steps: Step 1, Preparation of reaction raw materials: BASF fatty alcohol polyoxyethylene ether is placed in a dry reaction flask, followed by the addition of fumaric anhydride, ensuring full contact of the raw materials; Step 2, Deoxygenation and low-temperature dissolution: Nitrogen gas is purged into the reaction flask for thorough purging to completely remove air from the reaction system. After purging, the reaction flask is sealed, and the sealed reaction flask is placed in an oil bath for heating to completely dissolve the fumaric anhydride, obtaining a mixed solution; Step 3, Catalytic initiation... Grafting reaction: Add catalyst to the mixed solution, then gradually heat and continue stirring. During this reaction, monitor the reaction progress in real time using 1H NMR spectroscopy. When the characteristic peak of fumaric acid double bond disappears and the characteristic peak of maleic acid double bond appears, the reaction is considered complete, and the reaction mixture is obtained. Step 4, Product post-processing: Cool the reaction mixture to room temperature and let it stand. A white precipitate will form in the reaction mixture. Remove the white precipitate and collect the remaining liquid, which is the crude product of grafted fumaric acid. Step 5, Grafting rate determination: Determine the grafting rate of the crude product using 1H NMR spectroscopy.

[0007] Furthermore, in step two, the oil bath is heated to 50°C and kept under stirring at a stirring speed of 300 rpm until the fumaric anhydride is completely dissolved, and stirring is continued for 3 hours.

[0008] Furthermore, in step three, the catalyst is anhydrous aluminum chloride, the temperature is increased to 90°C at a heating rate of 5°C / min, and the reaction is continued to be stirred at a stirring rate of 300 rpm for 3.5 h.

[0009] Furthermore, in step four, the white precipitate is removed by centrifugation at 3000 rpm for 30 minutes.

[0010] Furthermore, in step five, a crude product sample is taken and dissolved in deuterated chloroform as a solvent, and then subjected to 1H NMR spectroscopy. In the 1H NMR spectrum, the integral value corresponding to the characteristic signal peak of the terminal methyl group and the integral value corresponding to the characteristic signal peak of the ortho-methylene group in the ester bond of the OEG unit are recorded respectively. The grafting rate formula is: grafting rate = (integral value corresponding to the characteristic signal peak of the ortho-methylene group in the ester bond of the OEG unit / 2) / (integral value corresponding to the characteristic signal peak of the terminal methyl group / 6) × 100%.

[0011] Furthermore, in step two, a nitrogen delivery tube is inserted into the bottom of the reaction flask, and nitrogen is introduced at a flow rate of 10 L / min to purge the inside of the reaction flask for 30 minutes to completely remove the air inside the flask, and then the reaction flask is sealed.

[0012] Furthermore, in step three, during the stirring reaction, samples are taken every 30 minutes to monitor the samples in real time using 1H NMR spectra.

[0013] The beneficial effects of this invention are as follows: It provides a method for preparing AEO-grafted fumaric acid, which has mild reaction conditions, high grafting efficiency, and high product purity. Furthermore, the reaction process can be precisely monitored by ¹H NMR spectroscopy to ensure complete reaction. Through the chemical modification of AEO with fumaric acid, a large number of highly polar carboxyl anions (-COO₂) are introduced. - In this process, the polyoxyethylene ether chain can bind to the carboxyl group via hydrogen bonding, while the carboxyl group of fumaric acid binds to the CO3²⁻ on the surface of sodium carbonate particles. - A neutralization reaction occurs, relying on the "polar bridging" effect of fumaric acid to provide a strong polar anchoring point for AEO, thus achieving stable adsorption of AEO on the surface of sodium carbonate particles; by chemically modifying the surface of sodium carbonate particles, it is transformed from an "ionic strong polar surface" into a "polar adsorption surface containing carboxyl anions", thereby forming an effective interaction with the polar end of AEO. Attached Figure Description

[0014] Figure 1 is a schematic diagram of the reaction formula of the present invention.

[0015] Figure 2 is an experimental diagram of XL80 in this invention.

[0016] Figure 3 is a secondary experimental diagram of XL80 in this invention.

[0017] Figure 4 is an experimental diagram of XL40 in this invention.

[0018] Figure 5 is an experimental diagram of XL50 in this invention.

[0019] Figure 6 is an experimental diagram of XL70 in this invention.

[0020] Figure 7 is an experimental diagram of XL90 in this invention. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0022] Those skilled in the art should understand that, in the disclosure of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting this invention.

[0023] It is understood that the term "a" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple, and the term "a" should not be understood as a limitation on the number.

[0024] As shown in Figures 1-7, this invention provides a method for synthesizing fumaric acid-modified nonionic surfactants, comprising the following steps: Step 1, Preparation of reaction raw materials: BASF fatty alcohol polyoxyethylene ether is placed in a dry reaction flask, followed by the addition of fumaric anhydride, ensuring full contact of the raw materials; Step 2, Deoxygenation and low-temperature dissolution: Nitrogen gas is introduced into the reaction flask for thorough purging to completely remove air from the reaction system. After purging, the reaction flask is sealed, and the sealed reaction flask is placed in an oil bath for heating to completely dissolve the fumaric anhydride and obtain a mixed solution; wherein, a nitrogen gas delivery tube is inserted into the bottom of the reaction flask, and nitrogen gas is introduced at a flow rate of 10 L / min to purge the inside of the reaction flask for 30 min to completely remove air from the flask, and then the reaction flask is sealed; the oil bath is heated to 50°C, and the mixture is kept under stirring conditions at a stirring rate of 300 rpm until the fumaric anhydride is completely dissolved, and stirring is continued for 3 h.

[0025] Step 3, Catalytic Grafting Reaction: Add the catalyst to the mixed solution, then gradually increase the temperature and continue stirring. During this reaction, monitor the reaction progress in real time using 1H NMR spectroscopy. When the characteristic peak of the fumaric acid double bond disappears and the characteristic peak of the maleic acid double bond appears, the reaction is considered complete, and the reaction mixture is obtained. The catalyst is anhydrous aluminum chloride. The temperature is increased to 90℃ at a rate of 5℃ / min, and the reaction is continued to be stirred at a rate of 300 rpm for 3.5 h. During the stirring reaction, samples are taken every 30 min, and the samples are monitored in real time using 1H NMR spectroscopy.

[0026] Step 4, Product post-processing: Cool the reaction mixture to room temperature and let it stand. A white precipitate will form in the reaction mixture. Remove the white precipitate and collect the remaining liquid, which is the crude product of grafted fumaric acid. The white precipitate is removed by centrifugation at 3000 rpm for 30 min.

[0027] Step 5: Grafting rate determination: The grafting rate of the crude product was determined by proton nuclear magnetic resonance spectroscopy.

[0028] The crude product sample was dissolved in deuterated chloroform and subjected to 1H NMR spectroscopy. The integral values ​​corresponding to the characteristic signal peak of the terminal methyl group and the characteristic signal peak of the ortho-methylene group in the ester bond of the OEG unit were recorded in the 1H NMR spectrum. The grafting rate formula is: grafting rate = (integral value of the characteristic signal peak of the ortho-methylene group in the ester bond of the OEG unit / 2) / (integral value of the characteristic signal peak of the terminal methyl group / 6) × 100%.

[0029] Based on the above synthesis method of fumaric acid modified nonionic surfactant, this scheme provides an implementation for further description: 1. Raw material feeding and system deoxygenation: Select a dry and clean 5L four-necked reaction flask, add XL80 (1kg, 3mol) into the reaction flask, and then accurately weigh 294g (3mol) fumaric anhydride into the reaction flask; insert a nitrogen gas delivery tube into the bottom of the reaction flask, and purge the inside of the reaction flask at a flow rate of 10L / min for 30min to completely remove the air in the flask, and then seal the reaction flask.

[0030] 2. First stage reaction: Place the sealed reaction flask in an oil bath, turn on the oil bath heating function to raise the temperature to 50°C, and at the same time turn on the stirring device and set the stirring speed to 300 rpm. Maintain this condition and stir until the fumaric anhydride in the reaction system is completely dissolved by visual observation. Then continue stirring for 3 hours.

[0031] 3. Second stage reaction: Add 3g of anhydrous aluminum chloride to the system through the feed port of the reaction flask, and then gradually raise the temperature of the oil bath to 90℃ (heating rate of 5℃ / min), and continue the reaction for 3.5h while maintaining the stirring rate of 300rpm. During the reaction, take a sample every 30min and detect the sample with ¹H NMR. Stop the reaction when the characteristic peak corresponding to the fumaric acid double bond (around 6.4ppm) completely disappears and the characteristic peak of the maleic acid double bond appears at around 6.2ppm.

[0032] 4. Post-processing and product separation: Turn off the oil bath and stirring device, remove the reaction flask, let it cool naturally to room temperature, and then place the reaction flask in a fume hood and let it stand overnight; the next day, a white precipitate was observed at the bottom of the reaction system. The reaction mixture was transferred to a centrifuge tube and centrifuged at 3000 rpm for 30 minutes using a high-speed centrifuge. After centrifugation, the upper transparent viscous liquid was taken, which is the crude product of XL40 grafted fumaric anhydride.

[0033] 5. Grafting rate determination: A small amount of crude product sample was taken and dissolved in deuterated chloroform as solvent, and ¹H NMR was performed. In the ¹H NMR spectrum, a characteristic signal peak of the terminal methyl group appeared at 0.88 ppm with an integral value of 6; a characteristic signal peak of the ortho-methylene group of the ester bond in the OEG unit appeared at 4.34 ppm, and the integral value of this peak was recorded as 1.67. According to the formula: Grafting rate = (integral value at 4.34 ppm / 2) / (integral value at 0.88 ppm / 6) × 100%, the grafting rate of the product was calculated to be 83.5%.

[0034] It is worth mentioning that, according to the above experimental steps, this scheme used BASF fatty alcohol polyoxyethylene ethers XL40, XL50, XL70, XL80, and XL90 as raw materials for comparative experiments. The experimental results are shown in Figures 2-7. Among them, Figures 2 and 3 are NMR data of XL80, with modification rates of 85% and 83.5%, respectively; Figure 4 is NMR data of XL40, with a modification rate of 56%; Figure 5 is NMR data of XL50, with a modification rate of 66%; Figure 6 is NMR data of XL70, with a modification rate of 69%; and Figure 7 is NMR data of XL90, with a modification rate of 70%.

[0035] The reason why the XL80 modification rate results corresponding to Figures 2 and 3 are different is that the amount of XL80 raw material in the first experiment was less than that in the second experiment, which resulted in some of the excess AEO in the first experiment not reacting completely, leading to different grafting rates. Subsequently, each experimental group adopted a linear process to ensure precise control of the amount of raw material added and to ensure that the proportion of each component in the reaction system remained constant, thereby improving the repeatability and accuracy of the grafting rate determination.

[0036] This invention is not limited to the preferred embodiments described above. Anyone can derive other products in various forms under the guidance of this invention. However, regardless of any changes in shape or structure, any technical solution that is the same as or similar to this application falls within the protection scope of this invention.

Claims

1. A method for synthesizing a fumaric acid-modified nonionic surfactant, characterized in that, Includes the following steps: Step 1: Preparation of Reaction Materials: Place BASF fatty alcohol polyoxyethylene ether in a dry reaction flask, then add fumaric anhydride, ensuring full contact of the raw materials. Step 2: Deoxygenation and Low-Temperature Dissolution: Thoroughly purge the reaction flask with nitrogen to completely remove air from the reaction system. After purging, seal the reaction flask and heat it in an oil bath to completely dissolve the fumaric anhydride, obtaining a mixed solution. Step 3: Catalytic Grafting Reaction: Add a catalyst to the mixed solution, then gradually increase the temperature and continue stirring. During this reaction, monitor the progress in real time using 1H NMR spectroscopy. When the characteristic peak of the fumaric acid double bond disappears and the characteristic peak of the maleic acid double bond appears, the reaction is considered complete, and the reaction mixture is obtained. Step 4: Product Post-treatment: Cool the reaction mixture to room temperature and allow it to stand. A white precipitate forms in the reaction mixture. Remove the white precipitate and collect the remaining liquid, which is the crude product of grafted fumaric acid. Step 5: Grafting Rate Determination: Determine the grafting rate of the crude product using 1H NMR spectroscopy.

2. The method for synthesizing fumaric acid-modified nonionic surfactant according to claim 1, characterized in that: In step two, the oil bath is heated to 50°C and stirred at a speed of 300 rpm until the fumaric anhydride is completely dissolved, and stirring is continued for 3 hours.

3. The method for synthesizing fumaric acid-modified nonionic surfactant according to claim 1, characterized in that: In step three, the catalyst is anhydrous aluminum chloride. The temperature is increased to 90°C at a rate of 5°C / min, and the reaction is continued to be stirred at a rate of 300 rpm for 3.5 h.

4. The method for synthesizing fumaric acid-modified nonionic surfactant according to claim 1, characterized in that: In step four, the white precipitate is removed by centrifugation at 3000 rpm for 30 minutes.

5. The method for synthesizing fumaric acid-modified nonionic surfactant according to claim 1, characterized in that: In step five, a crude product sample is taken and dissolved in deuterated chloroform as a solvent, and then subjected to 1H NMR spectroscopy. In the 1H NMR spectrum, the integral values ​​corresponding to the characteristic signal peak of the terminal methyl group and the integral values ​​corresponding to the characteristic signal peak of the ortho-methylene group in the ester bond of the OEG unit are recorded respectively. The grafting rate formula is: grafting rate = (integral value corresponding to the characteristic signal peak of the ortho-methylene group in the ester bond of the OEG unit / 2) / (integral value corresponding to the characteristic signal peak of the terminal methyl group / 6) × 100%.

6. The method for synthesizing fumaric acid-modified nonionic surfactant according to claim 1, characterized in that: In step two, insert the nitrogen delivery tube into the bottom of the reaction flask and purge the inside of the reaction flask at a flow rate of 10 L / min for 30 minutes to completely remove the air inside the flask, and then seal the reaction flask.

7. The method for synthesizing fumaric acid-modified nonionic surfactant according to claim 1, characterized in that: In step three, during the stirring reaction, samples are taken every 30 minutes to monitor the samples in real time using 1H NMR spectra.

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