Polyethylene glycol monoricinoleate and preparation method thereof

Abstract

The invention discloses polyethylene glycol monorricinoleate and a preparation method thereof. According to the method, polyethylene glycol and ricinoleic acid are taken as raw materials, metal organic framework material loaded heteropoly acid is taken as a catalyst, and polyethylene glycol monorricinoleate is prepared through esterification reaction. The polyethylene glycol monorricinoleate obtained by the method overcomes the defects of high reaction temperature, dark product color and tedious catalyst post-treatment in the traditional process, the selectivity and conversion rate of the polyethylene glycol monorricinoleate are remarkably improved, the catalyst can be separated only by filtration in post-treatment, the monorricinoleate is obtained with high selectivity, and the method is suitable for industrial production. The industrial production prospect is realized.

Description

Technical Field

[0001] The present invention relates to a polyethylene glycol monoricinoleate and a preparation method thereof, belonging to the technical field of organic synthesis. Background Art

[0002] In recent years, non-ionic surfactants have developed very rapidly and have important prospects for development and utilization.

[0003] The ricinoleic acid molecule contains rich active functional groups such as double bonds, hydroxyl groups, and carboxyl groups, and can undergo various chemical reactions such as addition and polymerization. The polyethylene glycol monoricinoleate prepared therefrom is a kind of non-ionic surfactant.

[0004] At present, the preparation methods of polyethylene glycol monoricinoleic acid at home and abroad, such as the catalytic synthesis of oleic acid monoesters from polyethylene glycol and oleic acid by sulfuric acid or solid acid, have low monoester yields and poor controllability. Other methods, such as the Chinese patent with the publication number CN102816324A, first esterifies polyethylene glycol with boric acid to protect one end of the hydroxyl group, then adds ricinoleic acid and p-toluenesulfonic acid as a catalyst to esterify again to form a boric acid polyethylene glycol ricinoleate diester, and finally hydrolyzes the boric acid polyethylene glycol ester group to obtain polyethylene glycol monoricinoleate. However, this method has problems such as complex processes and low product yields.

[0005] At present, the main method for industrial production of higher fatty acid monoesters is the direct esterification of higher fatty acids and alcohols by one-time feeding. The traditional production process uses inorganic acids represented by concentrated sulfuric acid as catalysts. Although sulfuric acid has high activity and low price as a catalyst, it has problems such as poor selectivity, many by-products, poor product quality, serious equipment corrosion, and the generation of a large amount of acidic wastewater and environmental pollution. The catalyst removal process is also cumbersome. Summary of the Invention

[0006] Aiming at the above-mentioned disadvantages in the prior art, the purpose of the present invention is to provide a polyethylene glycol monoricinoleate and a preparation method thereof. The present invention uses a metal-organic framework material loaded with heteropolyacid as a catalyst to esterify and synthesize polyethylene glycol monoricinoleate, which can reduce the reaction temperature and the color of the product, and significantly improve the selectivity and conversion rate.

[0007] The present invention uses a metal-organic framework material loaded with heteropolyacid to replace traditional sulfuric acid, which has stronger acidity and higher catalytic activity, and does not corrode equipment or pollute the environment. It can be used for homogeneous and heterogeneous reactions, and the catalyst recovery and treatment are simple and efficient. Moreover, a metal-organic framework material (MOF) with a large specific surface area is used as a carrier, and a heteropolyacid with strong catalytic activity is loaded as an esterification reaction catalyst, which can improve the reaction conversion rate and obtain ricinoleic acid polyethylene glycol monoesters with higher selectivity.

[0008] To achieve the above invention objectives, the technical solution adopted by the present invention is as follows:

[0009] A preparation method of polyethylene glycol monocastor oil acid ester, the method uses polyethylene glycol and castor oil acid as raw materials, and a metal-organic framework material loaded with heteropolyacid as a catalyst, and polyethylene glycol monocastor oil acid ester is prepared through an esterification reaction.

[0010] In the present invention, the molar ratio of castor oil acid to polyethylene glycol is 0.9:1 - 1.5:1, such as 0.9:1, 1:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, preferably 1.02:1 - 1.1:1.

[0011] In the present invention, the polyethylene glycol is selected from one or more of polyethylene glycol 400, polyethylene glycol 600, polyethylene glycol 800, and polyethylene glycol 1000, preferably polyethylene glycol 600.

[0012] In the present invention, the amount of the metal-organic framework material loaded with heteropolyacid is 1 - 5% of the mass of polyethylene glycol, such as 1%, 2%, 3%, 4%, 5%, preferably 2 - 3%.

[0013] In the present invention, for the metal-organic framework material loaded with heteropolyacid, the heteropolyacid loading is 1 - 20 wt%, such as 1%, 4%, 8%, 12%, 16%, 20 wt%, based on the total mass of the catalyst;

[0014] Among them, the heteropolyacid is selected from heteropolyacids containing at least any two elements of silicon, tungsten, phosphorus, molybdenum, etc., preferably silicotungstic heteropolyacid (H4SiW 12 O 40 , SiW 12 ), phosphotungstic heteropolyacid (H3PW 12 O 40 , PW 12 ), phosphomolybdic heteropolyacid (H3PMo 12 O 40 , PMo 12 ) one or more of them, preferably phosphotungstic heteropolyacid (PW 12 );

[0015] Among them, the metal-organic framework material (MOF) is selected from metallized 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin, preferably one or more of 5,10,15,20-tetrakis(4-carboxyphenyl)zinc porphyrin (Zn-TCPP), 5,10,15,20-tetrakis(4-carboxyphenyl)iron porphyrin (Fe-TCPP), 5,10,15,20-tetrakis(4-carboxyphenyl)aluminum porphyrin (Al-TCPP), preferably 5,10,15,20-tetrakis(4-carboxyphenyl)iron porphyrin (Fe-TCPP).

[0016] In the catalyst of the present invention, by loading heteropolyacid onto a metal-organic framework material, the homogeneous reaction in the prior art is carried out in a multiphase manner, thereby overcoming the problems that in the homogeneous reaction involving water participation or generation of heteropolyacid, it is difficult to recover the catalyst and it cannot be reused.

[0017] In the present invention, the metal-organic framework material loaded with heteropolyacid is a product already disclosed in the prior art. The present invention has no special requirements for its source. It can be directly purchased as a commercially available product or prepared based on the prior art. For example, it can be prepared by referring to the methods disclosed in the literature "Synthesis and Catalytic Performance of Functionalized MIL-101 Solid Acid Catalysts", "Acidity Regulation of Zr-based Metal-organic Framework UiO-66 and Its Catalytic Esterification Reaction of Oleic Acid", etc. One specific method is as follows:

[0018] Prepare an aqueous solution of heteropolyacid, add the metal-organic framework material, heat under reflux, filter after cooling, wash with ethanol, and dry to obtain;

[0019] Preferably, the concentration of the aqueous solution of heteropolyacid is 1-10 wt%, such as 1, 3, 5, 7, 10 wt%;

[0020] The mass ratio of the aqueous solution of heteropolyacid to the metal-organic framework material is 50-100:1, such as 50:1, 60:1, 70:1, 80:1, 90:1, 100:1;

[0021] For the heating under reflux, the temperature is 80-100 °C, such as 80, 85, 90, 95, 100 °C, and the time is 8-12 h, such as 8, 9, 10, 11, 12 h;

[0022] The cooling, filtering, washing, and drying are conventional operations in the field, and the present invention does not make specific limitations.

[0023] In the present invention, the ricinoleic acid is added in a continuous feeding manner, preferably in a dropping feeding manner; preferably, in the present invention, using the polyethylene glycol as the substrate, the ricinoleic acid is dropped at the reaction temperature;

[0024] Preferably, the feeding time is 150-250 min, and the feeding time is included in the esterification reaction time.

[0025] In the present invention, for the esterification reaction, the temperature is 100-150 °C, such as 100, 110, 120, 130, 140, 150 °C, preferably 120-130 °C; the time is 230-530 min, such as 230, 250, 280, 300, 350, 400, 450, 500, 530 min;

[0026] Preferably, the water collected is continuously withdrawn during the reaction process.

[0027] In the present invention, the esterification reaction is carried out in a solvent environment;

[0028] Preferably, the solvent is selected from alkanes having 6 to 10 carbon atoms, more preferably octane. The solvent can also be used as an azeotropic agent to remove water by azeotropic distillation;

[0029] Preferably, the amount of the solvent used is 0.3 to 0.5 times the mass of polyethylene glycol, such as 0.3, 0.4, or 0.5 times.

[0030] In the present invention, after the esterification reaction is completed, it further includes post-treatment processes such as filtering and recovering the catalyst and vacuum distillation, which are all conventional operations in the art and the present invention has no special requirements.

[0031] The polyethylene glycol monoricinoleate prepared by the method of the present invention has a hydroxyl value of 140 - 165 and an acid value of 10 - 40; the yield of the monoester reaches more than 85%, and the product chromaticity is lower than 200 PCU.

[0032] Compared with the prior art, the positive effects of the present invention are as follows:

[0033] In the present invention, polyethylene glycol and ricinoleic acid are used as raw materials, and a heteropolyacid supported on a metal-organic framework material is used to replace traditional sulfuric acid, p-toluenesulfonic acid, etc. as a catalyst, solving problems such as many by-products, serious corrosion of equipment, and difficulty in separating the catalyst and the reaction product after the reaction. At the same time, the reaction temperature and the product color can be reduced, and the selectivity and conversion rate are significantly improved. The polyethylene glycol monoricinoleate prepared by the present invention is widely applicable to fields such as industrial coatings and automotive coatings. Specific Embodiments

[0034] The following examples will further illustrate the process provided by the present invention, but the present invention is not limited to the listed examples and should also include any other known changes within the scope of the rights required by the present invention.

[0035] The main analysis methods adopted in the examples of the present invention are as follows:

[0036] Acid value and hydroxyl value: Determined by the methods of national standards HG / T 2709—95 and HG / T 2809—95;

[0037] Monoester content, %(mass content) = actual hydroxyl value / theoretical hydroxyl value of the product;

[0038] Actual hydroxyl value = hydroxyl value of the measured product - hydroxyl value of free ricinoleic acid;

[0039] Hydroxyl value of free ricinoleic acid = (acid value of the product / theoretical acid value of pure ricinoleic acid) * theoretical hydroxyl value of pure ricinoleic acid;

[0040] Chromaticity: Determined by the method of GB / T 605-2006

[0041] The source information of the main raw materials and reagents used in the embodiments of the present invention. Unless otherwise specified, other raw materials and reagents are obtained through commercial channels on the market:

[0042] Ricinoelaidic acid, ≥95.0% (T), >70% (GC), ALADDIN;

[0043] Polyethylene glycol 200, average Mn 200, innochem;

[0044] Polyethylene glycol 400, average Mn 400, innochem;

[0045] Polyethylene glycol 600, average Mn 600, innochem;

[0046] Polyethylene glycol 800, average Mn 800, innochem;

[0047] Polyethylene glycol 1000, average Mn 1000, innochem;

[0048] Sulfuric acid, 96%, ACROS;

[0049] Nitric acid, 65%, ACROS;

[0050] Silicotungstic acid, 98%, West Asia;

[0051] Phosphotungstic acid hydrate, 99%, INNOCHEM;

[0052] Phosphomolybdic acid hydrate, 98%, INNOCHEM;

[0053] Al-TCPP, CHEMSOON;

[0054] Fe-TCPP, CHEMSOON;

[0055] Zn-TCPP, CHEMSOON.

[0056] Preparation Example 1-4: Preparation of metal-organic framework material supported heteropolyacid catalyst (Catalysts 1-4)

[0057] Preparation Example 1

[0058] Preparation of metal-organic framework material supported heteropolyacid catalyst (Catalyst 1)

[0059] Prepare 200 g of an aqueous solution of silicotungstic acid with a concentration of 8 wt%, add 3 g of dried Al-TCPP, heat to 100 °C and reflux for adsorption for 3 h, filter after cooling, wash 4 times with ethanol, and dry at 120 °C for 3 h to obtain Catalyst 1 with a silicotungstic acid loading of 16 wt%, and place it in a desiccator for later use.

[0060] Preparation Example 2

[0061] Prepare a metal-organic framework material supported heteropolyacid catalyst (Catalyst 2)

[0062] Prepare 200 g of an aqueous solution of phosphotungstic acid with a concentration of 8 wt%, add 3 g of dried Fe-TCPP, heat to 100 °C and reflux for adsorption for 3 h, filter after cooling, wash 4 times with ethanol, and dry at 120 °C for 3 h to obtain Catalyst 2 with a phosphotungstic acid loading of 15 wt%, and place it in a desiccator for later use.

[0063] Preparation Example 3

[0064] Prepare a metal-organic framework material supported heteropolyacid catalyst (Catalyst 3)

[0065] Prepare 200 g of an aqueous solution of phosphomolybdic acid with a concentration of 8 wt%, add 3 g of dried Zn-TCPP, heat to 100 °C and reflux for adsorption for 3 h, filter after cooling, wash 4 times with ethanol, and dry at 120 °C for 3 h to obtain Catalyst 3 with a phosphomolybdic acid loading of 18 wt%, and place it in a desiccator for later use.

[0066] Preparation Example 4

[0067] Prepare a metal-organic framework material supported heteropolyacid catalyst (Catalyst 4)

[0068] Prepare 100 g of an aqueous solution of phosphotungstic acid with a concentration of 8 wt%, add 1 g of dried Al-TCPP, heat to 80 °C and reflux for adsorption for 3 h, filter after cooling, wash 4 times with ethanol, and dry at 120 °C for 3 h to obtain Catalyst 4 with a phosphotungstic acid loading of 7 wt%, and place it in a desiccator for later use.

[0069] Example 1

[0070] Prepare polyethylene glycol monocastor oil acid ester:

[0071] Take 760 g (1.267 mol) of polyethylene glycol 600, 300 g of octane, and 21.2 g of Fe-TCPP supported phosphotungstic heteropolyacid (Catalyst 2) in a three-necked flask, start stirring, add 378 g (1.267 mol) of castor oil acid dropwise at 130 °C over 200 min, continuously remove water by azeotropy during the process, and stir and keep warm for 120 min after the addition is complete. After the reaction is completed, filter to recover the catalyst, and remove octane by vacuum distillation to obtain polyethylene glycol monocastor oil acid ester.

[0072] The hydroxyl value of the sample test was 163.1 and the acid value was 13.2: The calculated content of polyethylene glycol 600 monoricinoleate was 87.0%, the conversion rate was 94.3%, the selectivity was 98.2%, and the chromaticity was 178 PCU.

[0073] The recovered catalyst was recycled 10 times. Then, the hydroxyl value of the sample test was 155.3, the acid value was 15.1, the conversion rate was 93.9%, the selectivity was 97.1%, and the chromaticity was 182 PCU.

[0074] Example 2

[0075] Prepare polyethylene glycol monoricinoleate:

[0076] Take 760 g (1.267 mol) of polyethylene glycol 600, 300 g of octane and 21.2 g of Al-TCPP supported phosphotungstic heteropolyacid (catalyst 1) in a three-necked flask, start stirring, and add 378 g (1.267 mol) of ricinoleic acid dropwise at 150 °C over a period of 200 min. During the process, water was continuously removed by azeotropic distillation. After the dropwise addition was completed, the mixture was stirred and kept warm for reaction for 30 min. After the reaction was completed, the catalyst was recovered by filtration, and octane was removed by vacuum distillation to obtain polyethylene glycol monoricinoleate.

[0077] The hydroxyl value of the sample test was 161.0, the acid value was 21.2, the conversion rate was 91.7%, the selectivity was 95.7%, and the chromaticity was 197 PCU.

[0078] Example 3

[0079] Prepare polyethylene glycol monoricinoleate:

[0080] Take 760 g (1.267 mol) of polyethylene glycol 600, 300 g of octane and 21.2 g of Zn-TCPP supported phosphotungstic heteropolyacid (catalyst 3) in a three-necked flask, start stirring, and add 378 g (1.267 mol) of ricinoleic acid dropwise at 100 °C over a period of 200 min. During the process, water was continuously removed by azeotropic distillation. After the dropwise addition was completed, the mixture was stirred and kept warm for reaction for 30 min. After the reaction was completed, the catalyst was recovered by filtration, and octane was removed by vacuum distillation to obtain polyethylene glycol monoricinoleate.

[0081] The hydroxyl value of the sample test was 161.1, the acid value was 19.4, the conversion rate was 91.5%, the selectivity was 95.9%, and the chromaticity was 128 PCU.

[0082] Example 4

[0083] Prepare polyethylene glycol monoricinoleate:

[0084] Take 760 g (1.267 mol) of polyethylene glycol 600, 300 g of octane and 7.6 g of Fe-TCPP supported phosphotungstic heteropolyacid (catalyst 4) in a three-necked flask, start stirring, and add 567 g (1.900 mol) of ricinoleic acid dropwise at 110 °C over 200 min. During the dropping process, water is continuously removed by azeotropic distillation. After the dropping is completed, stir and keep the temperature for reaction for 80 min. After the reaction is completed, filter to recover the catalyst, and remove octane by vacuum distillation to obtain polyethylene glycol monolaurate.

[0085] Sampling and testing shows that the hydroxyl value is 153.2, the acid value is 38.9, the conversion rate is 93.7%, the selectivity is 92.3%, and the chromaticity is 177 PCU.

[0086] Example 5

[0087] Preparation of polyethylene glycol monolaurate:

[0088] Take 760 g (1.267 mol) of polyethylene glycol 600, 300 g of octane and 38 g of Fe-TCPP supported phosphotungstic heteropolyacid (catalyst 2) in a three-necked flask, start stirring, and add 340 g (1.139 mol) of ricinoleic acid dropwise at 120 °C over 200 min. During the dropping process, water is continuously removed by azeotropic distillation. After the dropping is completed, stir and keep the temperature for reaction for 300 min. After the reaction is completed, filter to recover the catalyst, and remove octane by vacuum distillation to obtain polyethylene glycol monolaurate.

[0089] Sampling and testing shows that the hydroxyl value is 151.8, the acid value is 11.5, the conversion rate is 94.7%, the selectivity is 90.6%, and the chromaticity is 183 PCU.

[0090] Example 6

[0091] Preparation of polyethylene glycol monolaurate:

[0092] Take 760 g (1.267 mol) of polyethylene glycol 600, 380 g of heptane and 22.7 g of Fe-TCPP supported phosphotungstic heteropolyacid (catalyst 2) in a three-necked flask, start stirring, and add 378 g (1.267 mol) of ricinoleic acid dropwise at 130 °C over 200 min. During the dropping process, water is continuously removed by azeotropic distillation. After the dropping is completed, stir and keep the temperature for reaction for 330 min. After the reaction is completed, filter to recover the catalyst, and remove octane by vacuum distillation to obtain polyethylene glycol monolaurate.

[0093] Sampling and testing shows that the hydroxyl value is 151.0, the acid value is 14.5, the conversion rate is 90.2%, the selectivity is 94.7%, and the chromaticity is 192 PCU.

[0094] Example 7

[0095] Preparation of polyethylene glycol monolaurate:

[0096] Take 760 g (1.267 mol) of polyethylene glycol 600, 228 g of hexane and 22.7 g of Fe-TCPP supported phosphotungstic heteropolyacid (Catalyst 2) in a three-necked flask, start stirring, and add 378 g (1.267 mol) of ricinoleic acid dropwise at 130 °C over 200 min. During the dropping process, water is continuously removed by azeotropic distillation. After the dropping is completed, stir and keep the temperature for reaction for 230 min. After the reaction is completed, filter to recover the catalyst, and remove octane by vacuum distillation to obtain polyethylene glycol monoricinoleate.

[0097] Sampling and testing shows that the hydroxyl value is 149.1, the acid value is 12.9, the conversion rate is 93.6%, the selectivity is 91.8%, and the chromaticity is 162 PCU.

[0098] Comparative Example 1

[0099] Prepare polyethylene glycol monoricinoleate by referring to the method in Example 1, with the only difference being that sulfuric acid is used as the catalyst; after cooling, sampling and testing shows that the hydroxyl value is 160.6, the acid value is 76.0, the conversion rate is 96.5%, the selectivity is 66.0%, and the chromaticity is 755 PCU.

[0100] Comparative Example 2

[0101] Prepare polyethylene glycol monoricinoleate by referring to the method in Example 1, with the only difference being that phosphotungstic heteropolyacid is used as the catalyst; after cooling, sampling and testing shows that the hydroxyl value is 162.8, the acid value is 106.3, the conversion rate is 84.5%, the selectivity is 56.9%, and the chromaticity is 555 PCU.

[0102] Comparative Example 3

[0103] Prepare polyethylene glycol monoricinoleate by referring to the method in Example 1, with the only difference being that Fe-TCPP supported fluorosulfonic acid is used as the catalyst; after cooling, sampling and testing shows that the hydroxyl value is 141.9, the acid value is 64.9, the conversion rate is 73.4%, the selectivity is 75.3%, and the chromaticity is 328 PCU.

[0104] Comparative Example 4

[0105] Prepare polyethylene glycol monoricinoleate by referring to the method in Example 1, with the only difference being that alumina supported phosphotungstic heteropolyacid is used as the catalyst; after cooling, sampling and testing shows that the hydroxyl value is 119.7, the acid value is 12.5, the conversion rate is 78.7%, the selectivity is 87.1%, and the chromaticity is 362 PCU.

Claims

1. A preparation method of polyethylene glycol monolaurate, characterized in that, The method uses polyethylene glycol and ricinoleic acid as raw materials, and a metal-organic framework material loaded with heteropolyacid as a catalyst to prepare polyethylene glycol monoricinoleate through an esterification reaction.

2. The preparation method according to claim 1, characterized in that, The molar ratio of the ricinoleic acid to the polyethylene glycol is 0.9:1 - 1.5:1, preferably 1.02:1 - 1.1:

1.

3. The preparation method according to claim 1 or 2, characterized in that The polyethylene glycol is selected from one or more of polyethylene glycol 400, polyethylene glycol 600, polyethylene glycol 800, and polyethylene glycol 1000, preferably polyethylene glycol 600.

4. The preparation method according to any one of claims 1-3, characterized in that, The dosage of the metal-organic framework material loaded with heteropolyacid is 1 - 5% of the mass of the polyethylene glycol, preferably 2 - 3%.

5. The preparation method according to any one of claims 1-4, characterized in that, For the metal-organic framework material loaded with heteropolyacid, the heteropolyacid loading is 1 - 20 wt%, based on the total mass of the catalyst; Among them, the heteropolyacid is selected from heteropolyacids containing at least any two elements of silicon, tungsten, phosphorus, and molybdenum, preferably silicotungstic heteropolyacid (H4SiW 12 O 40 , SiW 12 ), phosphotungstic heteropolyacid (H3PW 12 O 40 , PW 12 ), phosphomolybdic heteropolyacid (H3PMo 12 O 40 , PMo 12 ), or one or more of them, preferably phosphotungstic heteropolyacid (PW 12 ).

6. The preparation method according to any one of claims 1-5, characterized in that, The metal-organic framework material (MOF) is selected from metallized 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin, preferably one or more of zinc 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (Zn-TCPP), iron 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (Fe-TCPP), and aluminum 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (Al-TCPP), preferably iron 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (Fe-TCPP).

7. The preparation method according to any one of claims 1-6, characterized in that, The ricinoleic acid is added continuously, preferably by dropwise addition. Preferably, using the polyethylene glycol as a substrate, the ricinoleic acid is added dropwise at the reaction temperature. Preferably, the feeding time is 150 - 250 min.

8. The preparation method according to any one of claims 1-7, characterized in that, For the esterification reaction, the temperature is 100 - 150 °C, preferably 120 - 130 °C; the time is 230 - 530 min.

9. The preparation method according to any one of claims 1-7, characterized in that, The esterification reaction is carried out in a solvent environment. Preferably, the solvent is selected from alkanes with 6 - 10 carbon atoms, more preferably octane, and the solvent can also be used as an azeotropic agent to remove water by azeotropy. Preferably, the dosage of the solvent is 0.3 - 0.5 times the mass of the polyethylene glycol.

10. Polyethylene glycol monoricinoleate prepared by the method according to any one of claims 1 - 9.