CN115124640A - Method for preparing polyacrylic acid solid - Google Patents
Method for preparing polyacrylic acid solid Download PDFInfo
- Publication number
- CN115124640A CN115124640A CN202210767416.0A CN202210767416A CN115124640A CN 115124640 A CN115124640 A CN 115124640A CN 202210767416 A CN202210767416 A CN 202210767416A CN 115124640 A CN115124640 A CN 115124640A
- Authority
- CN
- China
- Prior art keywords
- polyacrylic acid
- persulfate
- organic solvent
- sodium formate
- solid
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F120/00—Homopolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride, ester, amide, imide or nitrile thereof
- C08F120/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
- C08F120/04—Acids; Metal salts or ammonium salts thereof
- C08F120/06—Acrylic acid; Methacrylic acid; Metal salts or ammonium salts thereof
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F2/00—Processes of polymerisation
- C08F2/38—Polymerisation using regulators, e.g. chain terminating agents, e.g. telomerisation
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F6/00—Post-polymerisation treatments
Abstract
The invention relates to a method for preparing polyacrylic acid solid, belonging to the technical field of polyacrylic acid preparation. The method comprises the following steps: the first step, taking acrylic acid as a polymerization monomer, taking a mixed system of persulfate and hydrogen peroxide as an initiator to provide free radicals as active species, and taking sodium formate as a molecular weight regulator to synthesize polyacrylic acid; and secondly, slowly pouring the synthesized polyacrylic acid into an organic solvent to precipitate the polyacrylic acid, and centrifuging to obtain a white solid, namely the polyacrylic acid solid. The method utilizes the characteristic that the special polyacrylic acid is insoluble in an organic solvent, effectively removes water in the polyacrylic acid without high-temperature concentration, ensures the chromaticity and stability of the product, has simple process, high recovery rate, good selectivity, little pollution and lower cost, and has greater superiority compared with other methods.
Description
Technical Field
The invention belongs to the technical field of polyacrylic acid preparation, and particularly relates to a method for preparing polyacrylic acid solid.
Background
The low molecular weight polyacrylic acid is an important water treatment agent, and is mainly used as a calcium carbonate scale inhibitor and a dispersing agent of an industrial water circulation system. In the transportation process, factors such as transportation cost, safety and the like are considered, and polyacrylic acid is often required to be made into a solid product. At present, the most common method for preparing polyacrylic acid solid is spray drying, the solid content of polyacrylic acid product is adjusted to more than 60%, pH value is adjusted to 6-9, and spherical particles with particle size of 0.1-0.5mm are prepared by spray drying, grinding and sieving.
Disclosure of Invention
The object of the present invention is to provide a process for producing a polyacrylic acid solid, which is different from a process for obtaining a polyacrylic acid solid by heat treatment such as spray drying and belt drying, is a "cold-dry process", and can produce a polyacrylic acid solid simply and efficiently.
The invention mainly utilizes the principle that the solubility of polyacrylic acid products in a mixed phase of water and an organic solvent is reduced under the condition of a specific pH value, does not need to concentrate an aqueous solution of polyacrylic acid, and directly obtains solid precipitates in the mixed phase of water and the organic solvent.
Different from a common sodium polyacrylate sample neutralized by liquid alkali, the conventional sodium polyacrylate can be precipitated in an organic solvent only by adjusting the pH value of polyacrylic acid to 6.0-9.0 and adjusting the solid content of polyacrylic acid to be more than 65%, but under the conditions of the concentration and the pH value, the sodium polyacrylate solid obtained in a mixed phase is easy to adhere and compact into a colloid and is not easy to transfer and post-treat.
The invention uses sodium formate as molecular weight regulator, which can regulate the molecular weight in the process of synthesizing polyacrylic acid and adjust the pH value of polyacrylic acid. Different from liquid caustic soda, the solubility of polyacrylic acid in organic solvent is further reduced after sodium formate exists in polyacrylic acid, and even under the condition of high water content, the polyacrylic acid (or sodium salt thereof) can be separated out in a water-organic solvent mixed phase by slowly increasing the concentration of the organic solvent.
In order to realize the purpose, the invention adopts the technical scheme that:
a method of making polyacrylic acid solids comprising the steps of:
firstly, taking acrylic acid as a polymerization monomer, taking a mixed system of persulfate and hydrogen peroxide as an initiator to provide free radicals as active species, and taking sodium formate as a molecular weight regulator to synthesize polyacrylic acid;
and step two, slowly pouring the synthesized polyacrylic acid into an organic solvent to precipitate the polyacrylic acid, and centrifuging to obtain a white solid, namely the polyacrylic acid solid. The filtrate obtained after centrifugation can be recycled after rectification.
Further, in the second step, the volume ratio of the organic solvent to the polyacrylic acid is 1-10:1, preferably 3: 1.
Further, the first polyacrylic acid synthesis step comprises the following steps:
adding a certain amount of sodium formate into deionized water, heating to 85 ℃, stirring at the rotating speed of 150-200 r/min to completely dissolve the sodium formate to obtain a sodium formate solution;
weighing persulfate and hydrogen peroxide, dissolving in deionized water to prepare a persulfate and hydrogen peroxide solution, then dropwise adding acrylic acid and the persulfate and hydrogen peroxide solution into the sodium formate solution, and controlling the two solutions to be completely dripped within 2-4 h; after the dropwise addition is finished, reacting for 1-2h at constant temperature;
and (3) cooling the reacted solution to room temperature to obtain liquid, namely polyacrylic acid.
Further, the polyacrylic acid is insoluble in an organic solvent, and the organic solvent is one of methanol, ethanol, isopropanol, benzene and toluene.
Further, the amount of the sodium formate in the step (1) is 5-40% of the mass of the acrylic acid.
Further, the consumption of the persulfate in the step (2) is 1-5% of the mass of the acrylic acid, and the consumption of the hydrogen peroxide is 1-10% of the mass of the acrylic acid.
Further, the persulfate in the step (2) is one of sodium persulfate, ammonium persulfate and potassium persulfate.
Further, the constant temperature reaction temperature in the step (2) is 60-100 ℃, preferably 80-90 ℃, and more preferably 85 ℃.
Compared with the prior art, the invention has the beneficial effects that:
1. the method utilizes the characteristic that the special polyacrylic acid is insoluble in an organic solvent, effectively removes water in the polyacrylic acid without high-temperature concentration, ensures the chromaticity and stability of the product, has simple process, high recovery rate, good selectivity, little pollution and lower cost, and has greater superiority compared with other methods.
2. The invention has the advantages of less chemical raw material consumption, simple process, easy operation, no pollution, low product chromaticity and easy dissolution.
Detailed Description
The technical solutions and effects of the present invention are further described below with reference to specific examples, but the scope of the present invention is not limited thereto.
Example 1
A method for preparing polyacrylic acid comprises the following steps:
1. 15g of sodium formate and 50g of deionized water are weighed and placed in a four-neck flask, the temperature is raised to 85 ℃, and the sodium formate and the deionized water are stirred and dissolved.
2. Weighing 40g of acrylic acid monomer, and dropwise adding; 1.5g of sodium persulfate, 1.5g of hydrogen peroxide and 15g of deionized water are prepared into initiator solution, and simultaneously, acrylic monomer and the initiator solution are dropwise added for 3 hours at the temperature of 80-90 ℃.
3. After the dropwise addition of the materials, keeping the temperature at 85 ℃ for reaction for 1 hour, and cooling to normal temperature to obtain polyacrylic acid with the solid content of more than 45 percent, the Mw of about 2000 and the Pt-Co chroma of less than 40 degrees (Hazen).
Example 2
A method for preparing polyacrylic acid comprises the following steps:
1.5g of sodium formate and 40g of deionized water are weighed and placed in a four-neck flask, the temperature is raised to 85 ℃, and the mixture is stirred and dissolved.
2. Weighing 40g of acrylic acid monomer, and waiting for dropwise adding; preparing an initiator solution from 2g of sodium persulfate, 2g of hydrogen peroxide and 10g of deionized water, and simultaneously dropwise adding an acrylic monomer and the initiator solution for 2 hours at the temperature of 80-90 ℃.
3. After the dropwise addition of the materials, keeping the temperature at 85 ℃ for reaction for 2 hours, and cooling to normal temperature to obtain polyacrylic acid with the solid content of more than 48 percent, the Mw of about 8000 and the Pt-Co chroma of less than 20 degrees (Hazen).
Example 3
A preparation method of polyacrylic acid solid comprises the following steps:
100mL of methanol was measured, placed in a flask, and the stirring was turned on. 30mL of polyacrylic acid having a solid content of about 45% prepared in example 1 was weighed, and slowly added to the flask while stirring, and during the addition, white powdery solids were continuously precipitated from the polyacrylic acid solution. The stirring was turned off and the white solid allowed to settle naturally to the bottom of the flask. Transferring the supernatant into a beaker, transferring the bottom material into a centrifuge, and centrifuging for 10 minutes to obtain a white solid, namely polyacrylic acid solid, wherein the solid sample is weighed to obtain 14.2g, which accounts for about 80% of the total solid content of polyacrylic acid and has a solid content of 99.6%. And rectifying the centrifuged filtrate, purifying the methanol, and recycling the recovered solution which is polyacrylic acid with solid content of 25.5% and can be reused.
The polyacrylic acid solid thus prepared was dissolved in 14g of water to obtain a polyacrylic acid sample having a solids content of 50.1% and a recheck value of 30 to 40 degrees (Hazen).
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
Claims (8)
1. A method of making polyacrylic acid solids, comprising the steps of:
firstly, taking acrylic acid as a polymerization monomer, taking a mixed system of persulfate and hydrogen peroxide as an initiator to provide free radicals as active species, and taking sodium formate as a molecular weight regulator to synthesize polyacrylic acid;
and secondly, slowly pouring the synthesized polyacrylic acid into an organic solvent to precipitate the polyacrylic acid, and centrifuging to obtain a white solid, namely the polyacrylic acid solid.
2. The method of claim 1, wherein the volume ratio of the organic solvent to the polyacrylic acid in the second step is 1-10: 1.
3. The method of preparing polyacrylic acid solids according to claim 1, wherein the first step of polyacrylic acid synthesis comprises the steps of:
adding a certain amount of sodium formate into deionized water, heating to 85 ℃, stirring at the rotating speed of 150-200 r/min to completely dissolve the sodium formate to obtain a sodium formate solution;
weighing persulfate and hydrogen peroxide, dissolving in deionized water to prepare a persulfate and hydrogen peroxide solution, then dropwise adding acrylic acid and the persulfate and hydrogen peroxide solution into the sodium formate solution, and controlling the two solutions to be completely dripped within 2-4 h; after the dropwise addition is finished, reacting for 1-2h at constant temperature;
and (3) cooling the reacted solution to room temperature to obtain liquid, namely polyacrylic acid.
4. The method of claim 3, wherein the polyacrylic acid is insoluble in an organic solvent, wherein the organic solvent is one of methanol, ethanol, isopropanol, benzene, and toluene.
5. The method for preparing polyacrylic acid solids according to claim 3, wherein the amount of sodium formate used in step (1) is 5 to 40% by mass of acrylic acid.
6. The method for preparing polyacrylic acid solid according to claim 3, wherein the persulfate in the step (2) accounts for 1-5% of the mass of the acrylic acid, and the hydrogen peroxide accounts for 1-10% of the mass of the acrylic acid.
7. The method for preparing polyacrylic acid solids according to claim 3, wherein the persulfate in step (2) is one of sodium persulfate, ammonium persulfate, and potassium persulfate.
8. The method for preparing polyacrylic acid solid according to claim 3, wherein the isothermal reaction temperature in the step (2) is 60-100 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210767416.0A CN115124640A (en) | 2022-07-01 | 2022-07-01 | Method for preparing polyacrylic acid solid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210767416.0A CN115124640A (en) | 2022-07-01 | 2022-07-01 | Method for preparing polyacrylic acid solid |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115124640A true CN115124640A (en) | 2022-09-30 |
Family
ID=83381054
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210767416.0A Pending CN115124640A (en) | 2022-07-01 | 2022-07-01 | Method for preparing polyacrylic acid solid |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115124640A (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4622425A (en) * | 1979-08-24 | 1986-11-11 | Rhone-Poulenc Industries | Process for the preparation of aqueous solutions of low molecular weight polyacrylic acids or their salts |
| CN101423577A (en) * | 2008-12-10 | 2009-05-06 | 娄底市裕德科技有限公司 | Method for preparing polyacrylic acid or sodium polyacrylate |
| CN104151460A (en) * | 2014-08-20 | 2014-11-19 | 上海东升新材料有限公司 | Sodium polyacrylate for detergent and preparation method thereof |
| CN114671965A (en) * | 2022-04-20 | 2022-06-28 | 中国科学院福建物质结构研究所 | Nuclear-grade polyacrylic acid and preparation method and application thereof |
-
2022
- 2022-07-01 CN CN202210767416.0A patent/CN115124640A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4622425A (en) * | 1979-08-24 | 1986-11-11 | Rhone-Poulenc Industries | Process for the preparation of aqueous solutions of low molecular weight polyacrylic acids or their salts |
| CN101423577A (en) * | 2008-12-10 | 2009-05-06 | 娄底市裕德科技有限公司 | Method for preparing polyacrylic acid or sodium polyacrylate |
| CN104151460A (en) * | 2014-08-20 | 2014-11-19 | 上海东升新材料有限公司 | Sodium polyacrylate for detergent and preparation method thereof |
| CN114671965A (en) * | 2022-04-20 | 2022-06-28 | 中国科学院福建物质结构研究所 | Nuclear-grade polyacrylic acid and preparation method and application thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113582900A (en) | Preparation method of high-purity powdered dibenzoyl peroxide | |
| CN111004162B (en) | Method and device for preparing L-selenocysteine by using sodium triacetoxyborohydride as reducing agent | |
| CN113292471A (en) | Preparation method of micron-sized powdered dibenzoyl peroxide | |
| CN102180842B (en) | Synthesis method of 2-amino-delta 2-thiazoline-4-carboxylic acid | |
| CN112250543A (en) | Production process of medicinal raw material sodium methoxide | |
| US4125694A (en) | Process for the polymerization of allyl halides to form polyallyl alcohol | |
| CN112209819A (en) | Preparation method of D-pantoic acid calcium | |
| CN115124640A (en) | Method for preparing polyacrylic acid solid | |
| CN112724106A (en) | Synthetic method of high-purity TGDDM epoxy resin | |
| CN102531968A (en) | Process for preparation of l-arginine alpha-ketoglutarate 1:1 and 2:1 | |
| CN102746078A (en) | Preparation method for organic sulfonic acid compound | |
| CZ293993B6 (en) | Process for preparing substantially anhydrous magnesium chloride | |
| CN113651726B (en) | Preparation method of guanidinoacetic acid | |
| WO2024027016A1 (en) | Stable glacial acetic acid-sodium acetate compound and use thereof | |
| CN106800303B (en) | Method for preparing potassium iodide by using microchannel reactor | |
| CN111217718B (en) | Sulfur-free 2-bromo-4-fluoroacetanilide synthesis method | |
| CN108249804B (en) | Concentration method of ester polycarboxylate superplasticizer | |
| CN115215306A (en) | Preparation method and preparation equipment of high-purity bis (chlorosulfonyl) imide | |
| CN110437051B (en) | Preparation method of aluminum acetylacetonate | |
| CN113214418A (en) | Preparation method of high-porosity polyvinyl chloride | |
| US4069391A (en) | Process for the production of poly(allyl silicofurmate) | |
| WO2023195222A1 (en) | Method for producing 3,5-di-tertiary-butylsalicylic acid | |
| CN113856716B (en) | Hydrogenation catalyst for N- (2-nitroethyl) sodium taurate, preparation method and application thereof | |
| CN115784183B (en) | Preparation process of high-yield low-granularity aluminum phosphate | |
| CN113336680B (en) | Green process synthesis method of sulfanilamide |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |