CN113024796A - Refining method of polyethylene glycol - Google Patents
Refining method of polyethylene glycol Download PDFInfo
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- CN113024796A CN113024796A CN201911354305.1A CN201911354305A CN113024796A CN 113024796 A CN113024796 A CN 113024796A CN 201911354305 A CN201911354305 A CN 201911354305A CN 113024796 A CN113024796 A CN 113024796A
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G65/00—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule
- C08G65/02—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring
- C08G65/30—Post-polymerisation treatment, e.g. recovery, purification, drying
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- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
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- B01D15/00—Separating processes involving the treatment of liquids with solid sorbents; Apparatus therefor
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Abstract
The invention provides a refining method of polyethylene glycol, which comprises the following steps: adding a solid acid adsorbent into polyethylene glycol for adsorption treatment to obtain an adsorption solution; and filtering the adsorption solution to obtain refined polyethylene glycol. The refining method of the invention takes the solid acid as the adsorbent, omits the neutralization process, can carry out refining by one-time adsorption, and the used solid acid is not dissolved in the polyethylene glycol, can be conveniently removed from the product, shortens the process flow, does not generate obvious wastewater, improves the production efficiency and is environment-friendly.
Description
Technical Field
The invention relates to the field of polymers, in particular to a refining method of polyethylene glycol.
Background
Polyethylene glycol is an important chemical product, and is widely applied to various fields of biomedicine, daily chemicals, textile printing and dyeing, rubber and plastic, polyester and the like due to good water solubility and biocompatibility. However, due to different industries and different requirements for the quality of polyethylene glycol, the polyethylene glycol needs to be refined to remove metal ions and the like. Conventional metal ion removal methods are generally a neutralization-adsorption-filtration method and an ion exchange method.
The neutralization-adsorption-filtration method is generally operated by heating polyethylene glycol to a certain temperature, adding a proper amount of phosphoric acid for neutralization, adding magnesium silicate for adsorption after the neutralization is finished, and filtering to obtain refined polyethylene glycol after the adsorption is finished. The above process has the risk of unstable addition of phosphoric acid and need multiple times of neutralization and refining, and the obtained product has a large odor, which is not favorable for obtaining high-quality polyethylene glycol.
The ion exchange method generally comprises the steps of preparing polyethylene glycol into an aqueous solution with a certain concentration, then passing the aqueous solution through ion exchange resin, and finally heating and vacuum dehydrating to obtain refined polyethylene glycol. The method has the problems of ion exchange resin regeneration, large amount of process waste water and the like, and is not beneficial to large-scale industrial application.
Disclosure of Invention
The invention aims to provide a more advanced refining method of polyethylene glycol.
In order to achieve the purpose, the invention adopts the following technical scheme:
a refining method of polyethylene glycol comprises the following steps:
adding a solid acid adsorbent into polyethylene glycol for adsorption treatment to obtain an adsorption solution; and
and filtering the adsorption solution to obtain refined polyethylene glycol.
In some embodiments, the solid acid adsorbent is selected from tungsten trioxide, PO4 3-/ZrO2-SiO2Solid acid, fluosilicic acid, PO4 3-/MgO-Al2O3-SiO2One or more of sodium tungstate, anhydrous sodium hydrogen sulfite and tungstic acid.
In some embodiments, the temperature of the adsorption treatment is 70-130 ℃.
In some embodiments, the temperature of the adsorption treatment is 90-110 ℃.
In some embodiments, the time of the adsorption treatment is 20-120 min.
In some embodiments, the time of the adsorption treatment is 30-90 min.
In some embodiments, the solid acid adsorbent is present in an amount of 0.02% to 5% by weight of the polyethylene glycol.
In some embodiments, the solid acid adsorbent is used in an amount of 0.05% to 0.5% by weight of the polyethylene glycol.
In some embodiments, the polyethylene glycol has a molecular weight of 200-.
In some embodiments, the adsorption treatment is performed simultaneously with a vacuum treatment of the polyethylene glycol to remove moisture.
The refining method of the invention takes the solid acid as the adsorbent, omits the neutralization process, can carry out refining by one-time adsorption, and the used solid acid is not dissolved in the polyethylene glycol, can be conveniently removed from the product, shortens the process flow, does not generate obvious wastewater, improves the production efficiency and is environment-friendly.
Detailed Description
The technical solution of the present invention is further explained below according to specific embodiments. The scope of protection of the invention is not limited to the following examples, which are set forth for illustrative purposes only and are not intended to limit the invention in any way.
The refining method of polyethylene glycol of the invention comprises the following steps:
adding a solid acid adsorbent into polyethylene glycol for adsorption treatment to obtain an adsorption solution; and
filtering the adsorption solution to obtain refined polyethylene glycol.
By solid acid is meant a solid capable of donating a proton (B acid) or accepting an electron pair (L acid) as defined with reference to Bronsted and Lewis. The solid acid is generally a solid safe acid of a powder preparation, is organically compounded from respective safe powder preparations which can replace the acid part for use, can replace the acid in many fields, and has the characteristics of safe transportation, convenient transportation and convenient use.
The solid acid adsorbent used in the present invention is selected from tungsten trioxide and PO4 3-/ZrO2-SiO2Solid acid, fluorineSilicic acid, PO4 3-/MgO-Al2O3-SiO2One or more of monosodium tungstate, anhydrous sodium bisulfite and tungstic acid, and the solid acid adsorbent is added in powder form.
When the adsorption treatment is carried out, the temperature of the polyethylene glycol is raised to a proper temperature, and the temperature of the adsorption treatment is 70-130 ℃, preferably 90-110 ℃.
The time of the adsorption treatment is 20-120min, preferably 30-90min, so that the polyethylene glycol can be sufficiently adsorbed.
The dosage of the solid acid adsorbent is 0.02-5% of the polyethylene glycol, preferably 0.05-0.5% by weight, specifically, the dosage of the solid acid adsorbent is determined according to the content of metal ions in the polyethylene glycol to be adsorbed, too little dosage of the solid acid adsorbent cannot meet the requirement of removing the metal ions in the polyethylene glycol, and too much dosage of the solid acid adsorbent causes waste.
The polyethylene glycol treated by the invention can be polyethylene glycol with various molecular weights, and the molecular weight is preferably 200-6000.
The polyethylene glycol can be subjected to vacuum treatment while being subjected to adsorption treatment so as to remove trace moisture in the polyethylene glycol.
After the adsorption treatment is finished, a Buchner funnel can be adopted to filter the adsorption solution, and the collected filtrate is the refined polyethylene glycol.
The refining method of the invention takes the solid acid as the adsorbent, omits the neutralization process, can carry out refining by one-time adsorption, and the used solid acid is not dissolved in the polyethylene glycol, can be conveniently removed from the product, shortens the process flow, does not generate obvious wastewater, improves the production efficiency and is environment-friendly.
Unless otherwise defined, all terms used herein have the meanings that are commonly understood by those skilled in the art.
The present invention will be described in further detail with reference to examples.
Examples
The experimental procedures used in the following examples are all conventional procedures unless otherwise specified.
The materials, reagents and the like used in the following examples are commercially available, for example, commercially available analytical pure grade chemical reagents, unless otherwise specified.
Preparation example 1 PO4 3-/ZrO2-SiO2Synthesis of solid acid adsorbent
Reacting ZrCl2Dissolving in water, adding alcohol, and dripping ammonia water and silica sol into ZrCl2In solution (2) when ZrCl2Titration was complete when the solution pH ≈ 8.
Reacting ZrCl2Aging the solution for 12h, washing the solution with ethanol until no chloride ion exists, drying the solution, and roasting the solution at 400 ℃ for 2h to obtain ZrO2-SiO2And (3) a carrier.
By excess impregnation of ZrO2-SiO2The carrier being impregnated with a concentration of H3PO4Soaking for 6h, filtering, drying at 110 deg.C, and calcining at certain temperature for 3h to obtain PO4 3-/ZrO2-SiO2A solid acid adsorbent.
Preparation example 2 PO4 3-/MgO-Al2O3-SiO2Synthesis of (2)
Mixing MgCl2And Al (NO)3)3Dissolving in water, adding alcohol, and dripping ammonia water and silica sol into MgCl2And Al (NO)3)3In the solution (2), the titration is ended when the solution pH ≈ 10.
Will be provided with2Aging the solution for 10h, washing with ethanol until no chloride ion exists, drying, and roasting at 500 deg.C for 2h to obtain MgO-Al2O3-SiO2And (3) a carrier.
Using excess dipping method to mix MgO-Al2O3-SiO2The carrier being impregnated with a concentration of H3PO4Soaking for 4h, filtering, drying at 120 deg.C, and calcining at certain temperature for 3h to obtain PO4 3-/MgO-Al2O3-SiO2A solid acid adsorbent.
Preparation example 3 Synthesis of polyethylene glycol
Adding a certain amount of diethylene glycol into a reaction kettle, then adding catalysts such as hydroxides, hydrides or alcoholates of sodium and potassium, wherein the dosage of the catalysts is 0.25 percent of the mass of the product, and sealing the reaction kettle.
And replacing 3-5 times with nitrogen after the air tightness is detected to be qualified, then heating, introducing 5g of ethylene oxide after the temperature is raised to 100 ℃, continuously introducing and metering the ethylene oxide after the pressure is reduced and the temperature is raised, and controlling the reaction temperature to be 130-150 ℃ and the reaction pressure to be 0.1-0.5 MPa.
After the reaction is finished, continuously curing for 30-50 minutes, cooling to 70 ℃, and taking out the material, namely the polyethylene glycol required by the embodiment.
Example 1
Adding 200g PEG-200 into a three-neck flask, heating to 70 deg.C, and adding 0.04g solid acid adsorbent PO4 3-/ZrO2-SiO2Stirring and adsorbing for 20min, and simultaneously carrying out vacuum treatment to remove trace water in the PEG-200 during adsorption.
Filtering with Buchner funnel after adsorption, and collecting filtrate as refined polyethylene glycol. Detection of Na in polyethylene glycol by plasma emission spectrometer+、K+The results of concentration are shown in Table 1.
Example 2
Adding 200g of PEG-400 into a three-neck flask, heating to 70 ℃, then adding 0.10g of tungsten trioxide, stirring and adsorbing for 30min, and simultaneously carrying out vacuum treatment to remove trace moisture in the PEG-400.
Filtering with Buchner funnel after adsorption, and collecting filtrate as refined polyethylene glycol. Detection of Na in polyethylene glycol by plasma emission spectrometer+、K+The results of concentration are shown in Table 1.
Example 3
Adding 200g of PEG-600 into a three-neck flask, heating to 90 ℃, then adding 0.10g of tungsten trioxide, stirring and adsorbing for 30min, and simultaneously carrying out vacuum treatment to remove trace moisture in the PEG-600.
Completion of adsorptionThen, the mixture is filtered by a Buchner funnel, and the filtrate is collected to be refined polyethylene glycol. Detection of Na in polyethylene glycol by plasma emission spectrometer+、K+The results of concentration are shown in Table 1.
Example 4
Adding 200g PEG-1500 into a three-neck flask, heating to 100 deg.C, and adding 0.08g solid acid adsorbent PO4 3-/ZrO2-SiO2Stirring and adsorbing for 60min, and simultaneously carrying out vacuum treatment to remove trace water in the PEG-1500 during adsorption.
Filtering with Buchner funnel after adsorption, and collecting filtrate as refined polyethylene glycol. Detection of Na in polyethylene glycol by plasma emission spectrometer+、K+The results of concentration are shown in Table 1.
Example 5
Adding 200g of PEG-1500 into a three-neck flask, heating to 100 ℃, then adding 0.10g of fluosilicic acid, stirring and adsorbing for 60min, and carrying out vacuum treatment while adsorbing to remove trace moisture in the PEG-1500.
Filtering with Buchner funnel after adsorption, and collecting filtrate as refined polyethylene glycol. Detection of Na in polyethylene glycol by plasma emission spectrometer+、K+The results of concentration are shown in Table 1.
Example 6
200g PEG-2000 was added to a three-necked flask, the temperature was raised to 100 ℃ and then 0.10gPO was added4 3-/MgO-Al2O3-SiO2Stirring and adsorbing for 60min, and simultaneously carrying out vacuum treatment to remove trace water in PEG-2000.
Filtering with Buchner funnel after adsorption, and collecting filtrate as refined polyethylene glycol. Detection of Na in polyethylene glycol by plasma emission spectrometer+、K+The results of concentration are shown in Table 1.
Example 7
Adding 200g of PEG-2000 into a three-neck flask, heating to 100 ℃, then adding 0.10g of anhydrous sodium bisulfite, stirring and adsorbing for 90min, and simultaneously carrying out vacuum treatment to remove trace moisture in the PEG-2000.
Filtering with Buchner funnel after adsorption, and collecting filtrate as refined polyethylene glycol. Detection of Na in polyethylene glycol by plasma emission spectrometer+、K+The results of concentration are shown in Table 1.
Example 8
Adding 200g of PEG-4000 into a three-neck flask, heating to 110 ℃, then adding 0.20g of sodium hydrogen tungstate, stirring and adsorbing for 90min, and performing vacuum treatment while adsorbing to remove trace moisture in the PEG-4000.
Filtering with Buchner funnel after adsorption, and collecting filtrate as refined polyethylene glycol. Detection of Na in polyethylene glycol by plasma emission spectrometer+、K+The results of concentration are shown in Table 1.
Example 9
200g PEG-4000 was added to a three-necked flask, the temperature was raised to 110 ℃ and then 0.20gPO was added4 3-/MgO-Al2O3-SiO2Stirring and adsorbing for 90min, and simultaneously carrying out vacuum treatment to remove trace water in PEG-4000 during adsorption.
Filtering with Buchner funnel after adsorption, and collecting filtrate as refined polyethylene glycol. Detection of Na in polyethylene glycol by plasma emission spectrometer+、K+The results of concentration are shown in Table 1.
Example 10
Adding 200g PEG-6000 into three-neck flask, heating to 120 deg.C, and adding 0.30gPO4 3-/MgO-Al2O3-SiO2Stirring and adsorbing for 120min, and simultaneously carrying out vacuum treatment to remove trace moisture in PEG-6000.
Filtering with Buchner funnel after adsorption, and collecting filtrate as refined polyethylene glycol. Detection of Na in polyethylene glycol by plasma emission spectrometer+、K+The results of concentration are shown in Table 1.
Example 11
Adding 200g PEG-6000 into three-neck flask, heating to 70 deg.C, and adding 030g of solid acid adsorbent PO4 3-/ZrO2-SiO2Stirring and adsorbing for 120min, and simultaneously carrying out vacuum treatment to remove trace moisture in PEG-6000.
Filtering with Buchner funnel after adsorption, and collecting filtrate as refined polyethylene glycol. Detection of Na in polyethylene glycol by plasma emission spectrometer+、K+The results of concentration are shown in Table 1.
Example 12
Adding 200g of PEG-6000 into a three-neck flask, heating to 70 ℃, adding 0.30g of anhydrous sodium bisulfite, stirring and adsorbing for 120min, and performing vacuum treatment while adsorbing to remove trace moisture in the PEG-6000.
Filtering with Buchner funnel after adsorption, and collecting filtrate as refined polyethylene glycol. Detection of Na in polyethylene glycol by plasma emission spectrometer+、K+The results of concentration are shown in Table 1.
Comparative example 1
Adding a certain amount of unneutralized PEG2000 into a three-neck flask, heating to melt, neutralizing with phosphoric acid at 90-100 ℃ until the pH value is 4.0-5.0, continuously stirring for 1 hour, adding 1.5% of polyether refining agent (magnesium silicate) into the three-neck flask, heating to 100-110 ℃ while stirring, and stirring for 60-70 min under the condition of keeping the temperature.
And then, carrying out reduced pressure dehydration, wherein the vacuum degree is more than or equal to 0.095MPa, and the dehydration time is 30-40 min.
And finally, carrying out negative pressure filtration, and collecting filtrate which is refined polyethylene glycol. Detection of Na in polyethylene glycol by plasma emission spectrometer+、K+The results of concentration are shown in Table 1.
Comparative example 2
Adding a certain amount of polyethylene glycol 2000 crude ether into a glass three-neck flask, adding an equal amount of purified water, stirring and heating to 60 ℃, after 0.5h, allowing the materials to pass through a resin adsorption column at a speed of 250-300 g/h, after the completion, heating to 75 ℃, vacuumizing and dehydrating for 1h, then heating to 105 ℃, blowing nitrogen, then dehydrating for 2h in vacuum, and filtering while hot.
Collecting the filtrate as refined polyethylene glycol. Detection of Na in polyethylene glycol by plasma emission spectrometer+、K+The results of concentration are shown in Table 1.
TABLE 1 comparison of Na + and K + ion contents of polyethylene glycol before and after refining in examples and comparative examples
As can be seen from Table 1, compared with the comparative example, the ion content of the refined product in the example of the invention can reach the result that the ion content is equal to that of the neutralization-adsorption of phosphoric acid and the adsorption of ion exchange resin, but compared with the neutralization of phosphoric acid in the comparative example 1, the neutralization process is omitted, the product is prevented from having obvious sour taste, and the phenomenon of repeated refining which can occur when the adding amount of the neutralization agent is not accurate is avoided; compared with the comparative example 2, a large amount of water is not required to be added, the process of distilled water is omitted, the process flow is shortened, the energy consumption is reduced, and the generation of industrial wastewater is avoided.
It should be noted by those skilled in the art that the described embodiments of the present invention are merely exemplary and that various other substitutions, alterations, and modifications may be made within the scope of the present invention. Accordingly, the present invention is not limited to the above-described embodiments, but is only limited by the claims.
Claims (10)
1. A method for refining polyethylene glycol is characterized by comprising the following steps:
adding a solid acid adsorbent into polyethylene glycol for adsorption treatment to obtain an adsorption solution; and
and filtering the adsorption solution to obtain refined polyethylene glycol.
2. The purification process as claimed in claim 1, wherein the solid acid adsorbent is selected from tungsten trioxide, PO4 3-/ZrO2-SiO2Solid acid, fluosilicic acid, PO4 3-/MgO-Al2O3-SiO2One or more of sodium tungstate, anhydrous sodium hydrogen sulfite and tungstic acid.
3. The refining method according to claim 1, wherein the temperature of the adsorption treatment is 70 to 130 ℃.
4. The purification process according to claim 3, wherein the temperature of the adsorption treatment is 90 to 110 ℃.
5. The purification process according to claim 1, wherein the adsorption treatment is carried out for 20 to 120 min.
6. The purification process according to claim 5, wherein the adsorption treatment is carried out for 30 to 90 min.
7. The refining method of claim 1, wherein the solid acid adsorbent is used in an amount of 0.02 to 5 weight percent of the polyethylene glycol.
8. The refining method of claim 7, wherein the solid acid adsorbent is used in an amount of 0.05 to 0.5 weight percent of the polyethylene glycol.
9. The purification method as claimed in claim 1, wherein the polyethylene glycol has a molecular weight of 200-6000.
10. The refining method of any one of claims 1 to 9, further comprising subjecting the polyethylene glycol to a vacuum treatment to remove moisture while the adsorption treatment is performed.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115368628A (en) * | 2022-08-18 | 2022-11-22 | 无锡中天固废处置有限公司 | Desalting regeneration method of saliferous polyethylene glycol waste liquid |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104151541A (en) * | 2014-08-14 | 2014-11-19 | 上海多纶化工有限公司 | Polyether refinement method |
| CN104177608A (en) * | 2014-08-14 | 2014-12-03 | 上海多纶化工有限公司 | Method for refining polyether |
| CN106832249A (en) * | 2017-02-06 | 2017-06-13 | 山东诺威新材料有限公司 | The process for purification of low smell polyether polyol with high activity |
| CN108997572A (en) * | 2018-05-17 | 2018-12-14 | 浙江皇马科技股份有限公司 | A kind of block or atactic polyether aftertreatment technology |
-
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- 2019-12-25 CN CN201911354305.1A patent/CN113024796A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104151541A (en) * | 2014-08-14 | 2014-11-19 | 上海多纶化工有限公司 | Polyether refinement method |
| CN104177608A (en) * | 2014-08-14 | 2014-12-03 | 上海多纶化工有限公司 | Method for refining polyether |
| CN106832249A (en) * | 2017-02-06 | 2017-06-13 | 山东诺威新材料有限公司 | The process for purification of low smell polyether polyol with high activity |
| CN108997572A (en) * | 2018-05-17 | 2018-12-14 | 浙江皇马科技股份有限公司 | A kind of block or atactic polyether aftertreatment technology |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115368628A (en) * | 2022-08-18 | 2022-11-22 | 无锡中天固废处置有限公司 | Desalting regeneration method of saliferous polyethylene glycol waste liquid |
| CN115368628B (en) * | 2022-08-18 | 2024-03-19 | 无锡中天固废处置有限公司 | Desalination regeneration method of salt-containing polyethylene glycol waste liquid |
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Application publication date: 20210625 |