A preparation method of a novel anionic short branched polyol polyoxypropylene ether carboxylate surfactant

Abstract

The application discloses a preparation method of a novel anionic short branched chain polyol polyoxypropylene ether carboxylate surfactant. The method comprises the following steps: short branched chain polyol (3,8-dimethyl-1,4,7,10-decane tetrol) is subjected to ring-opening polymerization with propylene oxide (PO), and then is subjected to catalytic oxidation with noble metal (Pd / C) to prepare the short branched chain polyol polyoxypropylene ether carboxylate surfactant. The product has good wetting performance and foaming performance, and can be further applied to packaging plastic raw materials as a compatibilizer and a plasticizer, so as to improve the plasticity of brittle materials and the compatibility between blended materials.

Description

Technical Field

[0001] This invention belongs to the field of novel surfactant preparation technology, specifically relating to a method for preparing a novel surfactant of anionic short-chain branched polyol polyoxypropylene ether carboxylate. Background Technology

[0002] Alcohol ether carboxylates (AECs) are a novel class of surfactants with both anionic and nonionic properties. They possess a variety of excellent characteristics, such as good mildness, wetting properties, hard water resistance, good compatibility, and easy biodegradability, making them widely recognized as functional and environmentally friendly surfactants. Therefore, they can be widely used in cosmetics, industrial and household cleaning agents, metalworking fluids, biochemistry, textile auxiliaries, plastics, leather, pharmaceuticals, petroleum industry, food processing, and many other industries.

[0003] Structurally, it is divided into acidic form: R(CH2CH2O) n OCH2COOH

[0004] Salt form: R(CH2CH2O) n OCH2COOM

[0005] It is very similar to the structure of soap (RCOOM), except that EO / PO groups are inserted between the lipophilic and hydrophilic groups, thus having variable alkyl chain lengths and different degrees of ethoxylation and propoxylation. It not only overcomes the disadvantage of soap's poor resistance to hard water, but also retains the advantage of soap's non-excessive foaming.

[0006] The vast majority of current patent research involves two methods for synthesizing AEC using commercially available fatty alcohol ethers (AEO) series.

[0007] One method is carboxymethylation, represented by patent CN201510455671.1. This method describes the preparation of the product from alcohol ethers and sodium chloroacetate in the presence of alkali metal hydroxides and a phase transfer catalyst. The alcohol ether and phase transfer catalyst are added to a reactor, and the alkali metal hydroxide and sodium chloroacetate are mixed evenly and added in batches. After further aging, anhydrous ethanol is added, and the inorganic salts and excess sodium chloroacetate are removed by filtration. The anhydrous ethanol is then removed by distillation to obtain the alcohol ether carboxylate. While this method is simple to operate and has a high conversion rate, it cannot fundamentally solve the problem of byproduct residues that have adverse effects on the human body, thus limiting the product's application areas, especially in high-value-added, high-end surfactant applications such as personal care products. These shortcomings are almost insurmountable drawbacks of the carboxymethylation production process.

[0008] The second method is the noble metal oxidation method, represented by patent CN101357333A. This describes the addition of alkaline earth metals and transition metals as cofactors to a Pd / C catalyst to improve catalyst performance, directly catalytically oxidizing alcohol ethers to carboxylic acids based on the AEO series. In this catalytic oxidation method, the terminal hydroxymethyl group of aliphatic alcohol polyoxyethylene ether is oxidized to a carboxyl group in the presence of a noble metal catalyst. The catalytic oxidation method is environmentally friendly and offers advantages such as a short process flow, low equipment requirements, suitability for continuous production, and the ability to produce high-purity products. Its core and key lies in selecting and preparing a suitable catalyst. Summary of the Invention

[0009] The purpose of this invention is to provide a novel method for preparing anionic short-branched polyol polyoxypropylene ether carboxylate surfactant. This method involves ring-opening polymerization of short-branched tetraols with propylene oxide and catalytic oxidation with noble metal (Pd / C) to prepare alcohol ether carboxylate. The resulting product has a larger surface area wetting and foaming properties.

[0010] The above-mentioned objective of this invention can be achieved through the following technical solution: a method for preparing a novel anionic short-branched polyol polyoxypropylene ether carboxylate surfactant, comprising the following steps:

[0011] (1) Preparation of novel short-chain polyol ether: 3,8-dimethyl-1,4,7,10-decanetetrol and potassium hydroxide were added to a clean and dry reaction vessel, sealed, and the reaction vessel was replaced with N2 three times to remove the air in the vessel. The temperature was raised to 115℃~135℃, and the mixture was stirred continuously. The vacuum pump was turned on and the vessel was vacuum dehydrated for 20min~30min. In a nitrogen environment, propylene oxide was slowly added to the reaction vessel and reacted under constant temperature and pressure for 10min~20min. After the reaction was complete, the temperature was lowered to 70~90℃, glacial acetic acid was added to neutralize to neutral, the temperature was kept for 30min, cooled, and the material was discharged under N2 pressure to obtain the novel short-chain polyol ether.

[0012] (2) The novel short-chain branched polyol ether obtained in step (1), the noble metal Pd / C catalyst, sodium hydroxide, and water are added to the reactor. O2 is introduced into the reaction system and the temperature is kept constant at 110-120℃. The mixture is stirred continuously for 8-10 hours. After the reaction is completed, the mixture is centrifuged and the liquid is poured into a flask. Concentrated sulfuric acid is added to adjust the pH to 1-2. The residual sodium hydroxide is removed and the mixture is washed with water to obtain the novel anionic short-chain branched polyol polyoxypropylene ether carboxylic acid surfactant.

[0013] In this invention, several improvements were made to the structure of fatty alcohol ethers. A short-chain branched polyol (3,8-dimethyl-1,4,7,10-decanetetrol) was ring-opened polymerized with propylene oxide (PO). By adjusting the addition number of PO and the pH of the system, fatty alcohol ethers with different properties were prepared. Based on this, noble metal (Pd / C) catalytic oxidation was selected to prepare alcohol ether carboxylates, named PPEC. The obtained product is star-shaped with a network structure, exhibiting larger surface area wetting and foaming properties than previously studied chain-like alcohol ether carboxylates.

[0014] In the preparation method of the above-mentioned novel anionic short-branched polyol polyoxypropylene ether carboxylate surfactant:

[0015] Optionally, the volume ratio of 3,8-dimethyl-1,4,7,10-decanetetrol to propylene oxide in step (1) is 1:3 to 5.

[0016] Optionally, in step (1), propylene oxide is slowly added to the reactor over 1 hour.

[0017] Optionally, the ratio of the amount of the noble metal Pd / C catalyst to the amount of 3,8-dimethyl-1,4,7,10-decanetetrol in step (2) is 5 g: 100 mL.

[0018] The novel anionic short-branched polyol polyoxypropylene ether carboxylate surfactant prepared by the above method can be used as a modifying agent in the preparation of packaging plastics, such as as a compatibilizer or plasticizer in PPCP / PBAT blended plastic films.

[0019] Therefore, the method of this invention yields an alcohol ether carboxylate surfactant with superior wetting and defoaming properties, which can be used in the field of packaging material modifying agents. For example, it can be used as a compatibilizer or plasticizer in the preparation of PPCP / PBAT blend plastic films for packaging materials.

[0020] The present invention has the following advantages:

[0021] (1) The present invention designs and modifies the raw materials, uses short-chain tetraols and propylene oxide for ring-opening polymerization, and oxidizes them under the catalysis of noble metal (Pd / C) to prepare alcohol ether carboxylate. The resulting product is star-shaped and has a network structure, which has a larger area of ​​wetting and foaming properties.

[0022] (2) The product of the present invention can also be further applied to packaging plastic raw materials as compatibilizer and plasticizer to improve the plasticity of brittle materials and the compatibility between blended materials. For example, when added to PPCP / PBAT blended film, it can significantly improve the toughness and compatibility of PPCP / PBAT blended film, effectively solving the problems of poor plasticity of brittle materials and poor compatibility of blended materials. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the reaction process for preparing the novel anionic short-branched polyol polyoxypropylene ether carboxylate surfactant in Example 1. Detailed Implementation

[0024] The following examples of work are provided purely for illustrative purposes and should not be construed as limiting the scope of protection defined by the appended claims.

[0025] Unless otherwise specified, all raw materials used below are commercially available products, and all instruments or equipment used are conventional instruments or equipment.

[0026] Example 1

[0027] like Figure 1 As shown, the preparation method of the novel anionic short-branched polyol polyoxypropylene ether carboxylate surfactant provided in this embodiment includes the following steps:

[0028] (1) Preparation of novel short-chain polyol ether: 3,8-dimethyl-1,4,7,10-decanetetrol (100 mL) and potassium hydroxide were added to a clean and dry reaction vessel. The reaction vessel was sealed and replaced with N2 three times to remove the air inside the vessel. The temperature was raised to 120°C and stirred continuously. The vacuum pump was turned on and the vessel was vacuumed for 25 min to remove water. In a nitrogen atmosphere, 400 mL of propylene oxide was slowly added to the reaction vessel (to be added within 1 h). The reaction was carried out under constant temperature and pressure for 15 min. After the reaction was complete, the temperature was lowered to 80°C and glacial acetic acid was added to neutralize the ether. The mixture was kept at this temperature for 30 min, cooled, and discharged under N2 pressure to obtain the novel short-chain polyol ether.

[0029] (2) The novel short-chain branched polyol ether obtained in step (1), the noble metal Pd / C catalyst (5g), sodium hydroxide, and water were added to the reactor. O2 was introduced into the reaction system and the temperature was kept constant at 115℃. The mixture was stirred continuously for 9 hours. After the reaction was completed, the mixture was centrifuged and the liquid was poured into a flask. Concentrated sulfuric acid was added to adjust the pH to 1.5. The residual sodium hydroxide was removed and the novel short-chain branched polyol polyoxypropylene ether carboxylic acid surfactant was obtained after washing with water.

[0030] Example 2

[0031] (1) Preparation of novel short-chain polyol ethers: 100 mL of 3,8-dimethyl-1,4,7,10-decanetetrol and potassium hydroxide were added to a clean and dry reaction vessel. The vessel was sealed and purged with N2 three times to remove air. The temperature was raised to 115°C, and the mixture was stirred continuously. A vacuum pump was turned on to dehydrate the mixture under vacuum for 20 min. In a nitrogen atmosphere, 300 mL of propylene oxide was slowly added to the reaction vessel (to be added within 1 h). The reaction was carried out under constant temperature and pressure for 10 min. After the reaction was complete, the temperature was lowered to 80°C, and glacial acetic acid was added to neutralize the mixture. The mixture was kept at this temperature for 30 min, cooled, and discharged under N2 pressure to obtain the novel short-chain polyol ether.

[0032] (2) The novel short-branched polyol ether obtained in step (1), the noble metal Pd / C catalyst, sodium hydroxide, and water were added to a reactor. O2 was introduced into the reaction system, and the temperature was kept constant at 110°C. The mixture was stirred continuously for 8 hours. After the reaction was completed, the mixture was centrifuged, and the liquid was poured into a flask. Concentrated sulfuric acid was added to adjust the pH to 2 to remove residual sodium hydroxide. After washing with water, the novel anionic short-branched polyol polyoxypropylene ether carboxylic acid surfactant was obtained.

[0033] Example 3

[0034] (1) Preparation of novel short-chain polyol ether: 3,8-dimethyl-1,4,7,10-decanetetrol (100 mL) and potassium hydroxide were added to a clean and dry reaction vessel. The reaction vessel was sealed and replaced with N2 three times to remove the air inside the vessel. The temperature was raised to 135°C and stirred continuously. The vacuum pump was turned on and the vessel was vacuumed for 30 min to remove water. In a nitrogen atmosphere, 500 mL of propylene oxide was slowly added to the reaction vessel (to be added within 1 h). The reaction was carried out under constant temperature and pressure for 20 min. After the reaction was complete, the temperature was lowered to 80°C and glacial acetic acid was added to neutralize the ether to neutrality. The mixture was kept at this temperature for 30 min, cooled, and discharged under N2 pressure to obtain the novel short-chain polyol ether.

[0035] (2) The novel short-chain branched polyol ether obtained in step (1), the noble metal Pd / C catalyst, sodium hydroxide, and water were added to the reactor. O2 was introduced into the reaction system and kept at a constant temperature of 120°C. The mixture was stirred continuously for 10 hours. After the reaction was completed, the mixture was centrifuged and the liquid was poured into a flask. Concentrated sulfuric acid was added to adjust the pH to 1. The residual sodium hydroxide was removed and the novel short-chain branched polyol polyoxypropylene ether carboxylic acid surfactant was obtained after washing with water.

[0036] Comparative Example 1

[0037] Unlike Example 1, the reaction in step (1) is carried out at a constant temperature and pressure for 30 minutes.

[0038] Comparative Example 2

[0039] Unlike Example 3, concentrated sulfuric acid was added in step (2) to adjust the pH to 3.

[0040] The properties of the novel short-chain branched polyol polyoxypropylene ether carboxylic acid surfactants prepared in Examples 1-3 and Comparative Examples 1-2 are shown in Table 1 below.

[0041] Table 1. Comparison of performance indicators of surfactants prepared in Examples 1-3 and Comparative Examples 1-2

[0042]

[0043] Table 1 shows a performance comparison between different Examples 1-3 and Comparative Examples 1-2.

[0044] Compared to Comparative Examples 1-2, Table 1 shows that:

[0045] The surface tension (γ) of Examples 1-3 is less than 30 mN·cm. -1 This indicates that these three products have a strong ability to reduce surface tension, and the critical micelle concentration (C0) of oleyl alcohol, alcohol ether, and carboxylic acid is relatively high. mc It has a lower saturation level and stronger cleaning ability.

[0046] The surfactant aqueous solutions prepared in Examples 1-3 all produced foam volumes greater than 200 mL at 0 s, indicating that the products had good foaming ability.

[0047] The wetting time in Examples 1-3 was all within 200 seconds, indicating that the product has good wetting performance.

[0048] Examples 1-3 demonstrate the ability to disperse a large amount of solid particles, a desirable characteristic of heavy-duty cleaners. This dispersing ability helps remove dirt from surfaces and, most importantly, prevents redeposition of dirt by suspending it in the solution. The short-chain alcohol ether carboxylic acid series exhibits low transmittance, meaning that solid particles are suspended throughout the solution.

[0049] Examples 1-3 can form conductive pathways within the sample, reducing charge accumulation and thus serving as a good antistatic agent.

[0050] The performance testing methods are as follows:

[0051] 1. Surface tension: Tested according to GB / T 22237-2008 method, emulsions with different mass fractions were prepared, and the gas-liquid surface tension of the emulsions was measured using a surface tension meter.

[0052] 2. Critical micelle concentration: Plot a surface tension (γ)-concentration logarithm (1gc) curve. The concentration at the inflection point on the curve is the critical micelle concentration (CMC) of the surfactant.

[0053] 3. Foaming properties: Refer to GB / T13173.6-1991 to determine the foaming properties of a sample with a mass concentration of 2.5 g / L at 50°C using the modified Ross-Mile method, and record the foam volume of the sample at 0 s and 5 min.

[0054] 4. Wetting properties: The wetting time of the sample with a mass concentration of 2.5 g / L was tested according to GB / T 11983-1989 using the canvas sedimentation method. Each sample was measured three times and the average value was taken.

[0055] 5. Dispersibility: The high-strength, high-modulus vinylon fibers treated with AECNa (the novel short-chain branched polyol polyoxypropylene ether carboxylic acid surfactant prepared in Examples 1-3) emulsion were cut into short fibers with a length of 10 mm using a cutting device. Then, 0.05 g of the short-cut vinylon fibers were added to a stoppered graduated cylinder containing 500 mL of distilled water, shaken up and down 10 times, and allowed to stand until the bubbles disappeared. The dispersion effect was then observed.

[0056] 6. Antistatic properties: Weigh 15g of polyester staple fiber and immerse it in 1000mL of 0.5% aqueous solution. After soaking for 30min, wring out some of the water so that 30g of polyester remains. Place it in a 105℃ oven and dry for 2h. Then place it in an environment with a temperature of 23℃ and a humidity of 55% for 24h. Finally, use a fiber resistivity meter to measure the resistance value of the treated polyester staple fiber. Record the resistance reading and calculate its resistivity value according to formula (2): p=R×f Where: p is the fiber resistivity value (Q·cm); R is the measured resistance value (Q); f is the standard filling degree of the fiber material. The filling degree of polyester is 2.67cm.

[0057] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a novel anionic short-branched polyol polyoxypropylene ether carboxylate surfactant, characterized in that, Includes the following steps: (1) Preparation of novel short-chain polyol ether: 3,8-dimethyl-1,4,7,10decanetyl alcohol and potassium hydroxide were added to a clean and dry reaction vessel, sealed, and the reaction vessel was replaced with N2 three times to remove the air in the vessel. The temperature was raised to 115℃~135℃, and the mixture was stirred continuously. The vacuum pump was turned on and the vessel was vacuumed for dehydration for 20min~30min. In a nitrogen environment, propylene oxide was slowly added to the reaction vessel and reacted under constant temperature and pressure for 10min~20min. After the reaction was complete, the temperature was lowered to 70~90℃, glacial acetic acid was added to neutralize to neutral, the temperature was kept for 30min, cooled, and the material was discharged under N2 pressure to obtain the novel short-chain polyol ether. (2) The novel short-chain branched polyol ether obtained in step (1), the noble metal Pd / C catalyst, sodium hydroxide, and water are added to the reactor. O2 is introduced into the reaction system and the temperature is kept constant at 110-120℃. The mixture is stirred for 8-10 hours. After the reaction is completed, the mixture is centrifuged and the liquid is poured into a flask. Concentrated sulfuric acid is added to adjust the pH to 1-2. The residual sodium hydroxide is removed and the mixture is washed with water to obtain the novel anionic short-chain branched polyol polyoxypropylene ether carboxylic acid surfactant. The volume ratio of 3,8-dimethyl-1,4,7,10-decanetetrol to propylene oxide in step (1) is 1:3 to 5.

2. The preparation method of the novel anionic short-branched polyol polyoxypropylene ether carboxylate surfactant according to claim 1, characterized in that: In step (1), propylene oxide is slowly added to the reactor over 1 hour.

3. The preparation method of the novel anionic short-branched polyol polyoxypropylene ether carboxylate surfactant according to claim 1, characterized in that: The ratio of the amount of noble metal Pd / C catalyst used in step (2) to the amount of 3,8-dimethyl-1,4,7,10-decanetetrol is 5g:100mL.

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