Preparation method for treating isosorbide dimethyl ether by adopting membrane

Abstract

The invention relates to a preparation method for treating isosorbide dimethyl ether by adopting a membrane, and belongs to the technical field of organic synthesis. Adding isosorbide and a catalyst into a reaction kettle, and uniformly stirring and mixing to obtain a mixed material; uniformly mixing sodium methoxide and methanol to obtain a sodium methoxide-methanol solution; heating the mixed material, synchronously adding a sodium methoxide-methanol solution and distilled water, and carrying out an etherification reaction to obtain a mixed solution; the catalyst can be recovered in a magnetic separation manner in the reaction process; slowly dropwise adding hydrochloric acid into the mixed solution until the pH value is neutral, and then carrying out constant-temperature distillation to obtain a fraction solution; and carrying out reduced pressure distillation on the fraction liquid to remove residual methanol, and filtering through a modified ultrafiltration membrane to obtain the isosorbide dimethyl ether, the modified ultrafiltration membrane is modified through sorbic acid steam, argon, glutathione, papain, sodium bicarbonate and ethyl alcohol; the isosorbide dimethyl ether prepared by the method disclosed by the invention has relatively high purity and yield.

Description

Technical Field

[0001] This invention relates to the field of organic synthesis technology, and in particular to a method for preparing isosorbide dimethyl ether using membrane treatment. Background Technology

[0002] Isosorbide dimethyl ether, also known as isosorbide dimethyl ether, is an important organic compound. In the cosmetics industry, as an excellent solvent, penetrant, and moisturizer, its application in high-end skincare and makeup products will continue to increase as consumers demand higher efficacy and quality. In the pharmaceutical industry, as a drug carrier, solubilizer, and penetration enhancer, the demand for isosorbide dimethyl ether is also expected to continue to grow with the development of pharmaceutical technology and the research and development of new drugs. Furthermore, its applications in pesticides, fuels, and industrial solvents are gradually expanding, further driving up market demand.

[0003] Chinese Patent CN101445508B: Synthesis Method of Isosorbide Dimethyl Ether: (1) Add solvent, isosorbide, base and phase transfer catalyst to a reaction vessel; (2) Stir, heat to 80℃~100℃; reduce pressure to gauge pressure -0.095MPa, dehydrate; (3) Under phase transfer catalytic conditions, introduce chloromethane, complete the etherification reaction at a pressure of 0.1MPa~1.0MPa and a temperature of 50℃~90℃; (4) Neutralize with acid; (5) Filter and desalt; (6) Distill under reduced pressure, collect the fraction at 92℃~93℃, obtain the product isosorbide dimethyl ether and recover the solvent. The solvent is an alkyl-terminated low molecular weight polyether, where R1 and R2 are hydrogen atoms or alkyl groups; the alkyl group contains 1~15 carbon atoms; R3 and R4 are hydrogen atoms or methyl groups, or other lower alkyl groups; m+n is an integer from 4 to 15.

[0004] Chinese Patent CN114605426B: Belonging to the field of synthesis, specifically relating to a method for synthesizing isosorbide dimethyl ether, comprising the following steps: Step 1, adding isosorbide and a catalyst to a reaction vessel and mixing evenly to form a mixture; Step 2, mixing sodium methoxide and methanol evenly to obtain a sodium methoxide-methanol liquid; Step 3, heating the mixture to a liquid state, simultaneously adding the sodium methoxide-methanol liquid and distilled water, and stirring for etherification reaction for 5-8 hours to obtain a mixed solution; Step 4, slowly adding hydrogen chloride dropwise to the mixed solution until neutral, then distilling at a constant temperature for 20-40 minutes, and cooling the distilled gas to obtain a distillate; Step 5, distilling the distillate under reduced pressure for 2-3 hours to remove residual methanol, obtaining the product – isosorbide dimethyl ether.

[0005] The purity and yield of isosorbide dimethyl ether prepared by the above patents and existing technologies are relatively low and need to be further improved. Summary of the Invention

[0006] To address the above problems, this invention provides a method for preparing isosorbide dimethyl ether using membrane treatment, the steps of which are as follows:

[0007] S1 Raw material preparation: Add 72-88 parts isosorbide and 1-3 parts catalyst to the reactor and mix them evenly at a stirring speed of 500-800 r / min to obtain a mixture.

[0008] Mix 66-72 parts of sodium methoxide and 78-84 parts of methanol evenly to obtain sodium methoxide-methanol solution;

[0009] S2 Etherification Reaction: The mixture is heated to 55-65℃ to make it liquid, and sodium methoxide-methanol solution and distilled water are added simultaneously. The etherification reaction is carried out at a stirring speed of 500-1000 r / min to obtain a mixed solution. The catalyst can be recovered by magnetic separation during the reaction.

[0010] S3 Neutralization and Isothermal Distillation: Slowly add hydrochloric acid dropwise to the mixture until the pH is neutral. The dropwise rate of hydrochloric acid is 1-2 ml / min, and the mixture is stirred at a speed of 500-800 r / min during the dropwise addition. Distill at an isothermal temperature of 85-95℃ and 80-90% of atmospheric pressure for 20-40 min. Cool the distilled gas to 40-60℃ to obtain the distillate.

[0011] S4 vacuum distillation: The distillate is distilled under reduced pressure for 120-180 minutes at 60-70℃ and 70-80% of atmospheric pressure to remove residual methanol, and then filtered through a modified ultrafiltration membrane to obtain isosorbide dimethyl ether.

[0012] Preferably, the catalyst is one of the following: active alumina-based composite catalysts: WHA-101, ZTL-YQ-1.8-01, SS-LY10, and SS-LY30.

[0013] Preferably, the volume ratio of the added sodium methoxide-methanol solution to distilled water is 2-3:1.

[0014] Preferably, the sodium methoxide-methanol solution is added at a rate of 5-10 ml / min.

[0015] Preferably, the S2 etherification reaction is carried out at a temperature of 50-60°C, a pressure of 0.2-0.3 MPa, and a time of 5-8 hours.

[0016] Preferably, the modified ultrafiltration membrane is prepared by:

[0017] H1: The ultrafiltration membrane is placed in a radio frequency plasma generator and treated with a mixture of sorbic acid vapor and argon gas at a ratio of 1:10-20, at a power of 30-60W and a gas flow rate of 20-40sccm for 60-100 seconds to obtain a sorbic acid-based ultrafiltration membrane with double bonds.

[0018] H2: In a stirred tank, 10-18 parts of sorbic acid-based ultrafiltration membrane with double bonds, 0.002-0.05 parts of glutathione, 0.2-0.5 parts of papain, 1-3 parts of sodium bicarbonate, and 100-150 parts of ethanol are heated to 60-70℃ and stirred for 2-5 hours. After washing and drying, the modified ultrafiltration membrane is obtained.

[0019] Reaction mechanism

[0020] 1. Radio frequency plasma treatment causes sorbic acid groups to form on the surface of the ultrafiltration membrane.

[0021] Radio frequency plasma is an ionized gas that contains a large number of high-energy electrons, ions, free radicals and other active particles.

[0022] Introduction of sorbic acid groups: During the radio frequency plasma treatment, a gas containing sorbic acid or its related precursors is introduced. The active particles in the plasma promote the reaction of these gas molecules with free radicals on the ultrafiltration membrane surface, thereby grafting sorbic acid groups onto the ultrafiltration membrane surface. Sorbic acid molecules contain unsaturated double bonds and carboxyl groups, among other functional groups. The carboxyl groups impart hydrophilicity to the sorbic acid groups, thus enhancing the hydrophilicity of the ultrafiltration membrane surface.

[0023] 2. Addition reaction of sorbic acid-based ultrafiltration membranes with double bonds to glutathione and papain's thiol-olefin groups.

[0024] The thiol-olefin addition reaction, also known as the thiol-olefin reaction, is a very efficient click chemistry reaction. Its reaction mechanism is as follows:

[0025] Activation of the thiol group: Both glutathione and papain molecules contain a thiol (-SH) functional group. In the reaction system, the hydrogen atom on the thiol group has a certain acidity. Under appropriate conditions (such as the presence of a base catalyst or activation through other means), the hydrogen atom on the thiol group can leave, forming a sulfide anion (-S^-). The sulfide anion has strong nucleophilicity. The nucleophilic sulfide anion (-S^-) attacks one carbon atom of the carbon-carbon double bond on the surface of the sorbic acid-based ultrafiltration membrane, causing the pi bond to break, forming a new carbon-sulfur bond, and generating a new free radical (RC^cdot-CS-) on the other carbon atom.

[0026] The result of the reaction is that glutathione and papain are linked to the sorbic acid group on the surface of the ultrafiltration membrane through double bonds.

[0027] Technical effect

[0028] The present invention provides a method for preparing isosorbide dimethyl ether using membrane treatment. Compared with the prior art, the present invention has the following significant advantages:

[0029] 1. Enhanced hydrophilicity and increased water flux: Glutathione and papain themselves contain a large number of hydrophilic functional groups (such as hydroxyl, carboxyl, and amino groups). After being grafted onto the ultrafiltration membrane surface through a thiol-olefin addition reaction, the number of hydrophilic groups on the ultrafiltration membrane surface is further increased. The increased hydrophilicity makes it easier for water molecules to adsorb and pass through the membrane surface, thereby increasing the water flux.

[0030] 2. Improved antifouling properties and extended membrane lifespan: Increased hydrophilicity reduces the adsorption of pollutants (such as proteins and organic matter) on the membrane surface, as pollutants tend to adsorb onto hydrophobic surfaces. Furthermore, grafted glutathione and papain may possess certain biological or chemical activities that can inhibit or decompose some pollutants, further enhancing the membrane's antifouling ability. Improved antifouling properties reduce membrane clogging and performance degradation, thereby extending the membrane's lifespan.

[0031] 3. Improved filtration and purification of isosorbide dimethyl ether: Due to the increased water flux and improved antifouling properties, the ultrafiltration membrane can more effectively separate impurities when filtering isosorbide dimethyl ether, improving filtration efficiency and purification effect, resulting in higher purity of the obtained isosorbide dimethyl ether.

[0032] In summary, radio frequency plasma treatment and mercapto-olefin addition reaction have led to multifaceted improvements in the performance of ultrafiltration membranes, enhancing their effectiveness in filtering and purifying isosorbide dimethyl ether, etc. Detailed Implementation

[0033] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the following detailed description is provided in conjunction with embodiments and comparative examples:

[0034] Purity testing: Gas chromatography was used.

[0035] Example 1

[0036] A method for preparing isosorbide dimethyl ether using membrane treatment, comprising the following steps:

[0037] S1 Raw material preparation: Add 72g isosorbide and 1g catalyst to the reactor and mix evenly with a stirring speed of 500r / min to obtain a mixture.

[0038] Mix 66g of sodium methoxide and 78g of methanol evenly to obtain sodium methoxide-methanol solution;

[0039] S2 Etherification Reaction: The mixture is heated to 55°C to make it liquid, and sodium methoxide-methanol solution and distilled water are added simultaneously. The etherification reaction is carried out at a stirring speed of 500 r / min to obtain a mixed solution. The catalyst can be recovered by magnetic separation during the reaction.

[0040] S3 Neutralization and Isothermal Distillation: Hydrochloric acid is slowly added dropwise to the mixture until the pH is neutral. The dropwise rate of hydrochloric acid is 1 ml / min, and the mixture is stirred at 500 r / min during the dropwise process. The mixture is then isothermally distilled for 20 min at 85°C and 80% of atmospheric pressure. The distilled gas is then cooled to 40°C to obtain the distillate.

[0041] S4 Vacuum Distillation: The distillate was vacuum distilled for 120 min at 60°C and 70% of atmospheric pressure to remove residual methanol, and then filtered through a modified ultrafiltration membrane to obtain isosorbide dimethyl ether.

[0042] The catalyst is an active alumina-based composite catalyst, WHA-101.

[0043] The volume ratio of sodium methoxide-methanol solution to distilled water is 2:1.

[0044] The sodium methoxide-methanol solution was added at a rate of 5 ml / min.

[0045] The S2 etherification reaction was carried out at a temperature of 50°C, a pressure of 0.2 MPa, and a time of 5 hours.

[0046] The method for preparing the modified ultrafiltration membrane is as follows:

[0047] H1: The ultrafiltration membrane was placed in a radio frequency plasma generator and treated with a mixture of sorbic acid vapor and argon gas at a ratio of 1:10 for 60 seconds at a power of 30W and a gas flow rate of 20sccm; a sorbic acid-based ultrafiltration membrane with double bonds was obtained.

[0048] H2: In a stirred tank, 10g of sorbic acid-based ultrafiltration membrane with double bonds, 0.002g of glutathione, 0.2g of papain, 1g of sodium bicarbonate, and 100g of ethanol are heated to 60℃ and stirred for 2 hours. After washing and drying, the modified ultrafiltration membrane is obtained.

[0049] Example 2

[0050] A method for preparing isosorbide dimethyl ether using membrane treatment, comprising the following steps:

[0051] S1 Raw material preparation: Add 78g isosorbide and 2g catalyst to the reactor and mix evenly with a stirring speed of 600r / min to obtain a mixture.

[0052] Mix 68g of sodium methoxide and 80g of methanol evenly to obtain sodium methoxide-methanol solution;

[0053] S2 Etherification Reaction: The mixture is heated to 58°C to make it liquid, and sodium methoxide-methanol solution and distilled water are added simultaneously. The etherification reaction is carried out at a stirring speed of 600 r / min to obtain a mixed solution. The catalyst can be recovered by magnetic separation during the reaction.

[0054] S3 Neutralization and Isothermal Distillation: Hydrochloric acid is slowly added dropwise to the mixture until the pH is neutral. The dropwise addition rate of hydrochloric acid is 1.5 ml / min, and the mixture is stirred at 600 r / min during the addition process. The mixture is isothermally distilled for 25 min at 88°C and 85% of atmospheric pressure. The distilled gas is then cooled to 45°C to obtain the distillate.

[0055] S4 Vacuum Distillation: The distillate was vacuum distilled at 65°C and 75% of atmospheric pressure for 140 min to remove residual methanol, and then filtered through a modified ultrafiltration membrane to obtain isosorbide dimethyl ether.

[0056] The catalyst is an active alumina-based composite catalyst ZTL-YQ-1.8–01.

[0057] The volume ratio of sodium methoxide-methanol solution to distilled water is 2.5:1.

[0058] The sodium methoxide-methanol solution was added at a rate of 6 ml / min.

[0059] The S2 etherification reaction was carried out at a temperature of 55°C, a pressure of 0.2 MPa, and a time of 6 hours.

[0060] The method for preparing the modified ultrafiltration membrane is as follows:

[0061] H1: The ultrafiltration membrane was placed in a radio frequency plasma generator and treated with a mixture of sorbic acid vapor and argon gas at a ratio of 1:14 for 70 seconds at a power of 40W and a gas flow rate of 25sccm; a sorbic acid-based ultrafiltration membrane with double bonds was obtained.

[0062] H2: In a stirred tank, 12g of sorbic acid-based ultrafiltration membrane with double bonds, 0.02g of glutathione, 0.3g of papain, 2g of sodium bicarbonate, and 110g of ethanol were heated to 65℃ and stirred for 3 hours. After washing and drying, the modified ultrafiltration membrane was obtained.

[0063] Example 3

[0064] A method for preparing isosorbide dimethyl ether using membrane treatment, comprising the following steps:

[0065] S1 Raw material preparation: Add 84g isosorbide and 2g catalyst to the reactor and mix evenly with a stirring speed of 700r / min to obtain a mixture.

[0066] Mix 70g of sodium methoxide and 82g of methanol evenly to obtain sodium methoxide-methanol solution;

[0067] S2 Etherification Reaction: The mixture is heated to 63°C to make it liquid, and sodium methoxide-methanol solution and distilled water are added simultaneously. The etherification reaction is carried out at a stirring speed of 900 r / min to obtain a mixed solution. The catalyst can be recovered by magnetic separation during the reaction.

[0068] S3 Neutralization and Isothermal Distillation: Hydrochloric acid is slowly added dropwise to the mixture until the pH is neutral. The dropwise addition rate of hydrochloric acid is 1.5 ml / min, and the mixture is stirred at 700 r / min during the addition process. The mixture is isothermally distilled for 35 min at 93°C and 85% of atmospheric pressure. The distilled gas is then cooled to 55°C to obtain the distillate.

[0069] S4 Vacuum Distillation: The distillate was vacuum distilled at 65°C and 75% of atmospheric pressure for 160 min to remove residual methanol, and then filtered through a modified ultrafiltration membrane to obtain isosorbide dimethyl ether.

[0070] The catalyst is an active alumina-based composite catalyst SS-LY10.

[0071] The volume ratio of sodium methoxide-methanol solution to distilled water is 3:1.

[0072] The sodium methoxide-methanol solution was added at a rate of 8 ml / min.

[0073] The S2 etherification reaction was carried out at a temperature of 55°C, a pressure of 0.3 MPa, and a time of 7 hours.

[0074] The method for preparing the modified ultrafiltration membrane is as follows:

[0075] H1: The ultrafiltration membrane was placed in a radio frequency plasma generator and treated with a mixture of sorbic acid vapor and argon gas at a ratio of 1:18 for 90 seconds at a power of 50W and a gas flow rate of 35sccm; a sorbic acid-based ultrafiltration membrane with double bonds was obtained.

[0076] H2: In a stirred tank, 16g of sorbic acid-based ultrafiltration membrane with double bonds, 0.04g of glutathione, 0.4g of papain, 2g of sodium bicarbonate, and 140g of ethanol were heated to 65℃ and stirred for 4 hours. After washing and drying, the modified ultrafiltration membrane was obtained.

[0077] Example 4

[0078] A method for preparing isosorbide dimethyl ether using membrane treatment, comprising the following steps:

[0079] S1 Raw material preparation: Add 88g isosorbide and 3g catalyst to the reactor and mix evenly with a stirring speed of 800r / min to obtain a mixture.

[0080] 72g of sodium methoxide and 84g of methanol were mixed evenly to obtain sodium methoxide-methanol solution;

[0081] S2 Etherification Reaction: The mixture is heated to 65℃ to make it liquid, and sodium methoxide-methanol solution and distilled water are added simultaneously. The etherification reaction is carried out at a stirring speed of 1000 r / min to obtain a mixed solution. The catalyst can be recovered by magnetic separation during the reaction.

[0082] S3 Neutralization and Isothermal Distillation: Hydrochloric acid is slowly added dropwise to the mixture until the pH is neutral. The dropwise addition rate of hydrochloric acid is 2 ml / min, and the mixture is stirred at 800 r / min during the addition process. The mixture is isothermally distilled at 95°C and 90% of atmospheric pressure for 40 min. The distilled gas is then cooled to 60°C to obtain the distillate.

[0083] S4 Vacuum Distillation: The distillate was distilled under reduced pressure for 180 minutes at 70°C and 80% of atmospheric pressure to remove residual methanol. The distillate was then filtered through a modified ultrafiltration membrane to obtain isosorbide dimethyl ether.

[0084] The catalyst is an active alumina-based composite catalyst, SS-LY30.

[0085] The volume ratio of sodium methoxide-methanol solution to distilled water is 3:1.

[0086] The sodium methoxide-methanol solution is added at a rate of 10 ml / min.

[0087] The S2 etherification reaction was carried out at a temperature of 60°C, a pressure of 0.3 MPa, and a time of 8 hours.

[0088] The method for preparing the modified ultrafiltration membrane is as follows:

[0089] H1: The ultrafiltration membrane was placed in a radio frequency plasma generator and treated with a mixture of sorbic acid vapor and argon gas at a ratio of 1:20, at a power of 60W and a gas flow rate of 40sccm for 100 seconds to obtain a sorbic acid-based ultrafiltration membrane with double bonds.

[0090] H2: In a stirred tank, 18g of sorbic acid-based ultrafiltration membrane with double bonds, 0.05g of glutathione, 0.5g of papain, 3g of sodium bicarbonate, and 150g of ethanol were heated to 70℃ and stirred for 5 hours. After washing and drying, the modified ultrafiltration membrane was obtained.

[0091] Comparative Example 1

[0092] No modification was made to the ultrafiltration membrane; otherwise, it was the same as in Example 1.

[0093] Comparative Example 2

[0094] Without adding glutathione, otherwise the same as in Example 1.

[0095] Comparative Example 3

[0096] Papain was not added; otherwise, it was the same as in Example 1.

[0097] Table 1: Test Results

[0098] purity / % Yield / % Example 1 97.3 96.1 Example 2 97.9 96.5 Example 3 99.1 97.8 Example 4 99.5 98.3 Comparative Example 1 78.3 76.7 Comparative Example 2 91.5 88.2 Comparative Example 3 92.6 90.4

[0099] Based on the data analysis of the above examples and comparative examples, the isosorbide dimethyl ether prepared by the present invention has high purity and yield.

[0100] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for preparing isosorbide dimethyl ether using membrane treatment, characterized in that: Includes the following steps: S1 Raw material preparation: Add 72-88 parts isosorbide and 1-3 parts catalyst to the reactor and mix them evenly at a stirring speed of 500-800 r / min to obtain a mixture. Mix 66-72 parts of sodium methoxide and 78-84 parts of methanol evenly to obtain sodium methoxide-methanol solution; S2 Etherification Reaction: The mixture is heated to 55-65℃ to make it liquid, and sodium methoxide-methanol solution and distilled water are added simultaneously. The etherification reaction is carried out at a stirring speed of 500-1000 r / min to obtain a mixed solution. The catalyst can be recovered by magnetic separation during the reaction. S3 Neutralization and Isothermal Distillation: Slowly add hydrochloric acid dropwise to the mixture until the pH is neutral. The dropwise rate of hydrochloric acid is 1-2 ml / min, and the mixture is stirred at a speed of 500-800 r / min during the dropwise addition. Distill at an isothermal temperature of 85-95℃ and 80-90% of atmospheric pressure for 20-40 min. Cool the distilled gas to 40-60℃ to obtain the distillate. S4 vacuum distillation: The distillate is vacuum distilled at 60-70℃ and 70-80% of atmospheric pressure for 120-180 min to remove residual methanol, and then filtered through a modified ultrafiltration membrane to obtain isosorbide dimethyl ether. The modified ultrafiltration membrane is prepared by reacting it with cysteine ​​and papain after radio frequency plasma treatment to form sorbic acid groups on the surface of the ultrafiltration membrane.

2. The method for preparing isosorbide dimethyl ether using membrane treatment according to claim 1, characterized in that: The catalyst is one of the following: active alumina-based composite catalysts: WHA-101, ZTL-YQ-1.8-01, SS-LY10, and SS-LY30.

3. The method for preparing isosorbide dimethyl ether using membrane treatment according to claim 1, characterized in that: The volume ratio of sodium methoxide-methanol solution to distilled water is 2-3:

1.

4. The method for preparing isosorbide dimethyl ether using membrane treatment according to claim 1, characterized in that: The sodium methoxide-methanol solution is added at a rate of 5-10 ml / min.

5. The method for preparing isosorbide dimethyl ether using membrane treatment according to claim 1, characterized in that: The S2 etherification reaction is carried out at a temperature of 50-60℃, a pressure of 0.2-0.3 MPa, and a time of 5-8 hours.

6. The method for preparing isosorbide dimethyl ether using membrane treatment according to claim 1, characterized in that: The method for preparing the modified ultrafiltration membrane is as follows: H1: The ultrafiltration membrane is placed in a radio frequency plasma generator and treated with a mixture of sorbic acid vapor and argon gas at a ratio of 1:10-20, at a power of 30-60W and a gas flow rate of 20-40sccm for 60-100 seconds to obtain a sorbic acid-based ultrafiltration membrane with double bonds. H2: In a stirred tank, 10-18 parts of sorbic acid-based ultrafiltration membrane with double bonds, 0.002-0.05 parts of glutathione, 0.2-0.5 parts of papain, 1-3 parts of sodium bicarbonate, and 100-150 parts of ethanol are heated to 60-70℃ and stirred for 2-5 hours. After washing and drying, the modified ultrafiltration membrane is obtained.