CN112592429A - Preparation method of high-concentration polyacrylamide colloid - Google Patents

Preparation method of high-concentration polyacrylamide colloid Download PDF

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CN112592429A
CN112592429A CN202011474508.7A CN202011474508A CN112592429A CN 112592429 A CN112592429 A CN 112592429A CN 202011474508 A CN202011474508 A CN 202011474508A CN 112592429 A CN112592429 A CN 112592429A
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colloid
solution
agent
concentration
polymerization
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CN112592429B (en
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王勤
夏承波
何国锋
方叔迈
谢金生
卫巧磊
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JIANGSU FEYMER TECHNOLOGY CO LTD
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    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08FMACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F220/00Copolymers 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
    • C08F220/02Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
    • C08F220/52Amides or imides
    • C08F220/54Amides, e.g. N,N-dimethylacrylamide or N-isopropylacrylamide
    • C08F220/56Acrylamide; Methacrylamide
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    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08FMACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F2/00Processes of polymerisation
    • C08F2/38Polymerisation using regulators, e.g. chain terminating agents, e.g. telomerisation
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    • C08FMACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F2/00Processes of polymerisation
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    • C08F2/00Processes of polymerisation
    • C08F2/46Polymerisation initiated by wave energy or particle radiation
    • C08F2/48Polymerisation initiated by wave energy or particle radiation by ultraviolet or visible light
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    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08FMACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F283/00Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G
    • C08F283/06Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G on to polyethers, polyoxymethylenes or polyacetals
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    • C08FMACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F4/00Polymerisation catalysts
    • C08F4/04Azo-compounds
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    • C08FMACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F4/00Polymerisation catalysts
    • C08F4/40Redox systems
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    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08KUse of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00Use of inorganic substances as compounding ingredients
    • C08K3/16Halogen-containing compounds
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    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08KUse of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K5/00Use of organic ingredients
    • C08K5/16Nitrogen-containing compounds
    • C08K5/21Urea; Derivatives thereof, e.g. biuret

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Abstract

The invention discloses a preparation method of high-concentration polyacrylamide colloid, which comprises the following steps: preparing acrylamide and a comonomer into an aqueous solution; step two, adding a chain transfer agent, a chelating agent, a colloid reinforcing agent, a photoinitiator and an azo initiator into the aqueous solution prepared in the step one, and uniformly mixing to form a polymerization solution: step three, controlling the height of the polymerization solution in the step two, adjusting the pH value of the polymerization solution, and adding an oxidant solution and a reducing agent solution after deoxygenation to perform prepolymerization reaction; and step four, placing the prepolymer after the prepolymerization reaction in step three into ultraviolet light for illumination, and curing to obtain the high-concentration polyacrylamide colloid. The preparation method disclosed by the invention is used for preparing the high-concentration polyacrylamide colloid in a segmented initiation polymerization mode combining redox initiation and ultraviolet initiation, and the preparation method is high in production efficiency, stable in colloid property and high in solid content, and is beneficial to improving the production efficiency in an industrial production process.

Description

Preparation method of high-concentration polyacrylamide colloid
Technical Field
The invention belongs to the field of preparation of polyacrylamide, and particularly relates to a preparation method of a high-concentration polyacrylamide colloid.
Background
The polyacrylamide is called 'universal assistant' and has excellent adsorption, bridging and electric neutralization capacities. Common polyacrylamide on the market comprises three types, namely emulsion type, solution type and solid type, wherein the solid type has large annual consumption due to the characteristics of low transportation cost and long quality guarantee period.
In the production process of solid polyacrylamide, according to the characteristics of molecular weight, ionic degree and the like, colloid with the solid content of 20-35% is prepared, and then a granular or powdery product is formed after crushing, drying, grinding and screening, wherein more than 50% of moisture is usually removed in the drying process. Therefore, there is room for optimization of the production efficiency and drying cost of the solid type product. For high molecular weight polyacrylamide, increasing the monomer concentration often causes problems of molecular weight reduction and insoluble substance increase; for low molecular weight products below 100w, in order to ensure good molding of the colloid, the solid content is generally required to reach more than 50%, the polymerization heat of acrylamide reaches 82.8kJ/mol, when the monomer concentration reaches 25-30 wt%, if the heat dissipation is not good, the temperature in the polymerization process exceeds 100 ℃, so that a large amount of water vapor and other gases overflow at high temperature, the colloid rapidly expands before molding to form a sponge-shaped structure, the colloid is soft and sticky, and continuous production is generally difficult to realize, therefore, no low molecular weight polyacrylamide solid product exists on the market, no clear method for solving the problem is provided in the prior art, for example, patent CN107119008A discloses 'a low molecular weight amphoteric polyacrylamide and a preparation method thereof', the invention does not explain how to solve the problem of poor colloid strength caused by heat dissipation and high temperature, and simultaneously, the polymer with molecular weight below 100w has great colloid viscosity after heat preservation for 2h at 80 ℃, the subsequent section operation is difficult.
The production mode of the solid polyacrylamide is mainly a belt type production mode of ultraviolet light initiated polymerization and a kettle type production mode of redox initiated polymerization, but a single production mode is difficult to achieve monomer concentration of 50-65 wt%, for example, the highest monomer concentration is only 50 wt% in the synthesis method of ultraviolet light initiated hydrophobic modified cationic polyacrylamide disclosed in patent CN103073680B, and the reaction heat is difficult to remove due to the adopted heat insulation polymer system; for example, in the "preparation method of high molecular weight amphoteric polymer" disclosed in patent CN1314720C, the highest monomer concentration is only 40 wt%, and adiabatic kettle type polymerization is adopted, and the molecular weight of the prepared polymer reaches over 1000 w; however, both production methods cannot effectively solve the problem that the low molecular weight polyacrylamide colloid is sticky and soft without solving the problem of heat dissipation.
In view of the above, in order to solve some problems occurring in the production process of the present solid-type polyacrylamide products, a solution is needed.
Disclosure of Invention
The purpose of the invention is as follows: the invention aims to provide a preparation method of a high-concentration polyacrylamide colloid aiming at the technical problems that the concentration of a solid polyacrylamide product is difficult to improve and the low-molecular-weight solid polyacrylamide colloid is difficult to form in the prior art.
The technical scheme for realizing the invention is as follows:
the invention relates to a preparation method of a high-concentration polyacrylamide colloid, which comprises the following steps:
preparing acrylamide and a comonomer into an aqueous solution;
step two, adding a chain transfer agent, a chelating agent, a colloid reinforcing agent, a photoinitiator and an azo initiator into the aqueous solution prepared in the step one, and uniformly mixing to form a polymerization solution:
step three, controlling the height of the polymerization solution in the step two, adjusting the pH value of the polymerization solution, and adding an oxidant solution and a reducing agent solution after deoxygenation to perform prepolymerization reaction;
and step four, placing the prepolymer after the prepolymerization reaction in step three into ultraviolet light for illumination, and curing to obtain the high-concentration polyacrylamide colloid.
Preferably, when the prepolymerization reaction is carried out on the polymerization solution in the third step, the mass concentration of each component is as follows: 25-40 wt% of acrylamide, 5-30 wt% of comonomer, 0.01-0.1 wt% of chain transfer agent, 0.001-0.02 wt% of chelating agent, 1-7 wt% of colloid reinforcing agent, 1-10ppm of photoinitiator, 5-20ppm of azo initiator, 1-5 wt% of oxidant solution and 1-5 wt% of reducing agent solution.
Preferably, water is added into the polymerization solution in the third step to regulate the height of the polymerization solution to be in a range of 4-6 cm; the pH value of the polymerization solution is adjusted to 2-8.
Preferably, in the third step, the pH value is adjusted to 2-8 by sulfuric acid or sodium hydroxide, nitrogen is introduced into the polymerization solution for deoxygenation, the mass concentration of the oxidant solution is 5-20 wt%, and the mass concentration of the reducing agent solution is 5-20 wt%.
Preferably, in the first step, acrylamide and comonomer are prepared into an aqueous solution with monomer concentration of 50-65 wt%, the monomer concentration of 50-65 wt% is formed by combining monomers with different activities, and the content of acrylamide in the total monomer mass accounts for 50-80 wt%.
Preferably, the colloidal strengthening agent comprises one or more of a combination of a reactive cross-linking agent, a non-reactive solid content-promoting small molecule compound, and a non-reactive hydrogen bonding-promoting polar oligomer.
Preferably, the reactive crosslinking agent comprises N, N-methylene bisacrylamide, N-methylol acrylamide, polyallylamine or a combination of more than one of the above; the small molecular compound comprises one or more of urea, sodium chloride, ammonium sulfate, acetamide, ammonium adipate and ammonium chloride; the polar oligomer comprises one or more of polyoxyethylene with molecular weight less than 10000, polyvinyl alcohol and polyamine. In the preparation method, the polyacrylamide colloid with the molecular weight of less than 100w is soft and high in viscosity even if the concentration exceeds 50%, and the defects can be well compensated by adopting the colloid reinforcing agent; the reactive cross-linking agent is added to form a net-shaped structure, a branched structure and the like, physical entanglement points are increased, and the overall strength of the polyacrylamide colloid is improved; after the micromolecular compound is added, on one hand, the solid content of the product can be improved, the colloid hardness is improved, the continuous production is convenient, and on the other hand, the micromolecular compound can promote the dissolution of the product; the polar oligomer is added, so that the number of hydrogen bonds of the whole polyacrylamide colloid can be increased, the number of hydrogen bond binding points is increased, the internal stress of the colloid is greater than the adhesive force between the colloid and equipment, the colloid is convenient to separate from the equipment, and the strength and the viscosity of the colloid are improved.
Preferably, the prepolymerization reaction process in the third step is carried out in an open place with heat exchange with the outside, the highest temperature is less than 85 ℃, after the highest temperature is reached, the temperature is naturally reduced for 0.5 to 1 hour, and then the product enters the illumination area of the ultraviolet light in the fourth step for illumination. In the third step of the invention, a time interval is set between the redox initiation and the ultraviolet initiation, and after the redox reaction, the temperature is naturally reduced for 0.5 to 1 hour, the natural temperature reduction time gives time for the colloid to fully dissipate heat, thereby avoiding the phenomenon that the ultraviolet light causes the colloid to foam to form a sponge-shaped structure and generate insoluble substances when the reaction temperature exceeds 85 ℃ in the illumination process, and ensuring the continuous production of the colloid and the good molding of the colloid. In the invention, the prepolymerization reaction process is arranged in an open place with heat exchange with the outside, the height range of the polymerization liquid is regulated and controlled to be 4-6cm, and the thickness of the polymerization liquid is thinner, so that most of heat can be timely dissipated in the open place, and the stable reaction is further ensured, therefore, the temperature in the polymerization process of the prepolymerization reaction is lower than 85 ℃.
Preferably, the prepolymerization reaction time in the third step is 1-2h, the natural cooling time is included in the prepolymerization reaction time, the prepolymer is irradiated for 0.5-2h under ultraviolet light, and a high-concentration polyacrylamide colloid with the molecular weight of less than 100w is obtained after curing.
The product prepared by the preparation method comprises the steps of preparing a solid dispersing agent with the molecular weight less than or equal to 100w, a dry strength agent, a fluid loss agent, a flocculating agent, a scale inhibitor and a thickening agent.
The monomer concentration of the invention is as high as 50-65 wt%, and the polymerization rate and reaction temperature are difficult to control by adopting a one-step method, so that a composite initiation mode of redox initiation and ultraviolet initiation is adopted, and the key point is that different active monomers are selected for combination; high-activity monomers, such as acrylamide, AM, and acrylic acid, AA, are difficult to control because the reaction rate is fast if the concentration of the monomers is more than 90%, so that the monomer combination is prepared by combining high-activity and low-activity monomers, such as AM and DMC cationic monomer, AM and methacrylamide, MAPTAC, and the like; regulating and controlling the reaction rate by regulating the initiation temperature and the dosage of the initiator; the higher the initiation temperature of the monomer combination, the lower the reaction activation energy, and the faster the reaction rate, so for different reactive monomer combinations, the low reactive monomer combination needs to be properly raised in reaction temperature, and the high reactive monomer combination needs to be lowered in reaction temperature; for a high-concentration system, the use amount of an oxidant and a reducing agent is higher, and the use amount of a thermal initiator and a photoinitiator is less, because the viscosity of the early-stage polymerization liquid is small, the heat dissipation is easier, the use amount of the oxidant and the reducing agent is large, the reaction can be kept continuously, but the reaction is carried out to a certain extent, the number of free radicals in the system is reduced, the thermal initiator needs to be decomposed for continuous initiation, in order to ensure the stable reaction, the use amount of the thermal initiator is less, and the final ultraviolet light illumination stage is also the same; if the two initiators are used in too much amount, the polymerization rate is accelerated, and the reaction temperature is increased instantly, which is not beneficial to the preparation of products; the thinner thickness of the polymerization solution allows most of the heat to be dissipated in an open environment in time, so that the temperature during the polymerization process of the prepolymerization reaction is less than 85 ℃.
The preparation method of the invention prepares the polyacrylamide colloid with the polymer concentration of 50-65 wt% by a segmented initiation polymerization mode combining redox initiation and ultraviolet initiation, solves the problems of large heat release, high temperature, large colloid viscosity, difficult continuous production and the like caused by increasing the monomer concentration in the production process of solid polyacrylamide products, and is particularly suitable for preparing products with the molecular weight of less than 100w, such as dispersing agents, dry strength agents, filtrate loss reducing agents, flocculating agents, scale inhibitors, thickening agents and the like. The method provided by the invention has the advantages of high production efficiency, stable colloidal property and high solid content, and is beneficial to the improvement of the production efficiency in the industrial production process.
By adopting the technical scheme, the invention has the following beneficial effects:
(1) the invention prepares the high-concentration polyacrylamide colloid by a segmented initiation polymerization mode combining redox initiation and ultraviolet initiation, the segmented initiation mode enables the reaction to be controllable, the over-high temperature in the reaction process can be prevented, the heat of the polymerization liquid can be dissipated in time by controlling the height of the polymerization liquid, the reaction temperature is reduced, the hardness of the colloid can be increased by adding the colloid reinforcing agent, the strength and the viscosity of the colloid are improved, and the continuous production is realized.
(2) In the preparation method, the monomer concentration is 50-65 wt%, wherein the acrylamide content is 50-80 wt%, the reaction rate, the heat release rate and the heat dissipation rate are controlled by controlling the monomer ratio, the initiator dosage and the colloid thickness, so that the temperature in the polymerization process is lower than 85 ℃, the rapid expansion and contraction of the colloid are avoided, the colloid does not form a sponge-shaped structure, the integral strength is improved, and the continuous production degree is achieved.
(3) The highest temperature in the prepolymerization process is less than 85 ℃, and after reaching the highest temperature, the temperature is naturally reduced for 0.5 to 1 hour and then the product enters the illumination area of the ultraviolet light in the step four for illumination. The time interval is set between the redox initiation and the ultraviolet light initiation, and after the redox reaction, the temperature is naturally reduced for 0.5 to 1 hour, the natural temperature reduction time gives the time for fully radiating the colloid, thereby avoiding the phenomenon that the reaction temperature of the ultraviolet light exceeds 85 ℃ in the illumination process to cause the colloid to foam to form a sponge-shaped structure and generate insoluble substances, and ensuring the continuous production of the colloid and the good molding of the colloid.
(4) In the invention, the prepolymerization reaction process is arranged in an open place with heat exchange with the outside, the height range of the polymerization liquid is regulated and controlled to be 4-6cm, and the thinner thickness of the polymerization liquid ensures that most heat can be timely dissipated in the open place, thereby further ensuring the stable reaction.
(5) According to the invention, the colloid reinforcing agent is added into the polymerization liquid, the polyacrylamide colloid with the molecular weight of less than 100w is soft and high in viscosity when the concentration of the polyacrylamide colloid exceeds 50%, and the defects are difficult to pass through conveying equipment such as rollers, chain plate machines and pipelines, and the colloid reinforcing agent is added to better compensate for the defects, wherein the reactive cross-linking agent in the colloid reinforcing agent can form a net-shaped structure, a branched structure and the like, the physical entanglement points are more, and the overall strength of the colloid is improved; the micromolecular compound in the colloid reinforcing agent can improve the solid content of the product per se, improve the colloid hardness, facilitate continuous production and promote the dissolution of the product; the polar oligomer in the colloid reinforcing agent can improve the number of hydrogen bonds of the whole colloid, the number of hydrogen bond binding points is increased, the internal stress of the colloid is greater than the adhesive force between the colloid and equipment, and the colloid is convenient to separate from the equipment, so that the strength and the viscosity of the colloid are improved, and the quality of the colloid is ensured.
(6) The preparation method can be used for preparing solid dispersing agents, dry strength agents, filtrate loss reducing agents, flocculating agents, scale inhibitors and thickening agents with the molecular weight of less than 100w, widens the product types and application range of polyacrylamide, and can be popularized and used in the market.
(7) The preparation method adopted by the invention is simple, has high production efficiency, stable colloid property and high solid content, and is beneficial to improving the production efficiency in the industrial production process; the highest temperature is lower than 100 ℃, and the damage to equipment and production environment is extremely low.
(8) The water content in the colloid prepared by the preparation method is reduced by more than 10% compared with that in the prior art, so that the drying cost can be saved, and the production efficiency can be improved.
Detailed Description
The technical solution of the present invention is described in detail below, but the scope of the present invention is not limited to the embodiments.
Example 1: a preparation method of high-concentration polyacrylamide colloid comprises the following steps:
preparing acrylamide and a comonomer into an aqueous solution; acrylamide and comonomer are prepared into aqueous solution with monomer concentration of 50-65 wt%, the monomer concentration of 50-65 wt% is formed by combining monomers with different activities, wherein the proportion of the acrylamide content in the total monomer mass is 50-80 wt%;
step two, adding a chain transfer agent, a chelating agent, a colloid reinforcing agent, a photoinitiator and an azo initiator into the aqueous solution prepared in the step one, and uniformly mixing to form a polymerization solution:
step three, controlling the height of the polymerization liquid in the step two to enable the height range to be 4-6 cm; adjusting the pH value to 2-8 by sulfuric acid or sodium hydroxide, and introducing nitrogen to remove oxygen; adding an oxidant solution with the mass concentration of 5-20 wt% and a reducing agent solution with the mass concentration of 5-20 wt% after removing oxygen to carry out prepolymerization reaction; in the embodiment, when the prepolymerization reaction is performed on the polymerization solution, the mass concentrations of the components are as follows: 25-40 wt% of acrylamide, 5-30 wt% of comonomer, 0.01-0.1 wt% of chain transfer agent, 0.001-0.02 wt% of chelating agent, 1-7 wt% of colloid reinforcing agent, 1-10ppm of photoinitiator, 5-20ppm of azo initiator, 1-5 wt% of oxidant solution and 1-5 wt% of reducing agent solution; finally, adjusting the height range of the polymerization solution by adding water into the polymerization solution;
after the prepolymerization reaction is carried out for 1-2h in the step three, the prepolymer after the prepolymerization reaction is irradiated for 0.5-2h under ultraviolet light, and high-concentration polyacrylamide colloid with the molecular weight of less than 100w is obtained after curing; in the embodiment, the prepolymerization reaction process is carried out in an open place with heat exchange with the outside, the highest temperature is less than 85 ℃, after the highest temperature is reached, the temperature is naturally reduced for 0.5 to 1 hour, the natural temperature reduction time is included in the prepolymerization reaction time, and then the prepolymerization reaction process enters the illumination area of the ultraviolet light in the step four for illumination. In the third step of the present embodiment, a time interval is set between the redox initiation and the ultraviolet initiation, and after the redox reaction, the temperature is naturally reduced for 0.5 to 1 hour, and the natural temperature reduction time provides the time for the colloid to fully dissipate heat, thereby preventing the ultraviolet light from causing the colloid to foam to form a "sponge" structure and generate insoluble substances when the reaction temperature exceeds 85 ℃ in the illumination process, and ensuring continuous production of the colloid and good molding of the colloid. In the embodiment, the prepolymerization reaction process is arranged in an open place with heat exchange with the outside, the height range of the polymerization liquid is regulated and controlled to be 4-6cm, the thickness of the thin polymerization liquid enables most of heat to be timely dissipated in the open place, and the stable reaction is further ensured, so that the temperature in the polymerization process of the prepolymerization reaction is lower than 85 ℃.
The colloid reinforcing agent in the embodiment comprises one or more combinations of a reactive cross-linking agent, a non-reactive solid content-promoting small molecular compound and a non-reactive hydrogen bond-promoting polar oligomer; the reactive crosslinking agent comprises N, N-methylene bisacrylamide, N-hydroxymethyl acrylamide and one or more of polyallylamine; the small molecule compound comprises one or more of urea, sodium chloride, ammonium sulfate, acetamide, ammonium adipate and ammonium chloride; the polar oligomer comprises one or more of polyethylene oxide with molecular weight less than 10000, polyvinyl alcohol and polyamine. In the preparation method of the embodiment, the polyacrylamide colloid with the molecular weight of less than 100w is soft and has high viscosity even if the concentration exceeds 50%, and the defects can be well compensated by adopting the colloid reinforcing agent; the reactive cross-linking agent is added to form a net-shaped structure, a branched structure and the like, physical entanglement points are increased, and the overall strength of the polyacrylamide colloid is improved; after the micromolecular compound is added, on one hand, the solid content of the product can be improved, the colloid hardness is improved, the continuous production is convenient, and on the other hand, the micromolecular compound can promote the dissolution of the product; the polar oligomer is added, so that the number of hydrogen bonds of the whole polyacrylamide colloid can be increased, the number of hydrogen bond binding points is increased, the internal stress of the colloid is greater than the adhesive force between the colloid and equipment, the colloid is convenient to separate from the equipment, and the strength and the viscosity of the colloid are improved.
In the embodiment, the product prepared by the preparation method comprises the steps of preparing a solid dispersing agent with the molecular weight less than or equal to 100w, a dry strength agent, a fluid loss agent, a flocculating agent, a scale inhibitor and a thickening agent.
In the embodiment, the concentration of the monomer is as high as 50-65 wt%, and the polymerization rate and the reaction temperature are difficult to control by adopting a one-step method, so that a composite initiation mode of redox initiation and ultraviolet initiation is adopted, and the key point is that different active monomers are selected for combination; high-activity monomers, such as acrylamide, AM, and acrylic acid, AA, are difficult to control because the reaction rate is fast if the concentration of the monomers is more than 90%, so that the monomer combination is prepared by combining high-activity and low-activity monomers, such as AM and DMC cationic monomer, AM and methacrylamide, MAPTAC, and the like; regulating and controlling the reaction rate by regulating the initiation temperature and the dosage of the initiator; the higher the initiation temperature of the monomer combination, the lower the reaction activation energy, and the faster the reaction rate, so for different reactive monomer combinations, the low reactive monomer combination needs to be properly raised in reaction temperature, and the high reactive monomer combination needs to be lowered in reaction temperature; for a high-concentration system, the use amount of an oxidant and a reducing agent is higher, and the use amount of a thermal initiator and a photoinitiator is less, because the viscosity of the early-stage polymerization liquid is small, the heat dissipation is easier, the use amount of the oxidant and the reducing agent is large, the reaction can be kept continuously, but the reaction is carried out to a certain extent, the number of free radicals in the system is reduced, the thermal initiator needs to be decomposed for continuous initiation, in order to ensure the stable reaction, the use amount of the thermal initiator is less, and the final ultraviolet light illumination stage is also the same; if the two initiators are used in too much amount, the polymerization rate is accelerated, and the reaction temperature is increased instantly, which is not beneficial to the preparation of products; the thinner thickness of the polymerization solution allows most of the heat to be dissipated in an open environment in time, so that the temperature during the polymerization process of the prepolymerization reaction is less than 85 ℃.
In this example, the preparation method was verified according to the preparation method described above and experimental data of specific values:
firstly, preparing a polymerization solution according to the contents in the first step to the third step, adding 224.5g of acrylamide solution of high-activity monomer with the mass fraction of 50%, 40.2g of low-activity monomer methacryloyloxyethyl trimethyl ammonium chloride with the mass fraction of 80%, 8.3g of low-activity monomer dimethylaminoethyl methacrylate, 0.12g of chain transfer agent sodium methallylate, 3.6g of low-activity itaconic acid, 5g of small molecular compound urea, 5g of small molecular compound sodium chloride, 0.1g of chelating agent pentasodium ethylene diamine tetraacetate and 5g of deionized water into a reaction kettle, and stirring and dissolving uniformly; adding a photoinitiator and an azo initiator into the reaction kettle, wherein the photoinitiator is preferably 0.15g of Darocur 1173 solution with the concentration of 1 wt%, namely 2-hydroxy-2-methyl-1-phenyl-1-acetone, the azo initiator is preferably 0.1g of VA-044 solution with the concentration of 1 wt%, namely azobisisobutylimidazoline hydrochloride, and 0.15g of V-50 solution with the concentration of 1 wt%, namely azobisisobutylamidine dihydrochloride, stirring and mixing all the components in the reaction kettle uniformly, and then adjusting the pH value of the polymerization solution to 3 by using sulfuric acid;
then, controlling the solution temperature of the polymerization solution after adjusting the pH value by a water bath to be 30 ℃, starting to introduce nitrogen to remove oxygen, introducing nitrogen for 20min, then adding an oxidant solution, continuing to introduce nitrogen for 2min, and then adding a reducing agent solution, wherein the oxidant solution is preferably a tert-butyl hydroperoxide solution with the concentration of 2.5g and the reducing agent solution is preferably a sodium bisulfite solution with the concentration of 2.5g and the concentration of 15 wt%; stopping introducing nitrogen after the polymerization liquid is sticky, standing for 1h for prepolymerization reaction, wherein the highest temperature in the prepolymerization reaction process is 82 ℃, naturally cooling after the highest temperature reaches 82 ℃, and then placing the reaction kettle under ultraviolet light for light irradiation for 1 h; finally, the prepared colloid is taken out, and after granulation, drying, crushing and screening, amphoteric polyacrylamide solid powder with the molecular weight of 34.6 ten thousand and the content of insoluble substances of less than 0.01 percent is obtained.
Experimental data in the embodiment show that the preparation method in the embodiment can be used for preparing the high-concentration polyacrylamide gel with the monomer concentration of 50-65 wt% to obtain a final product with the molecular weight of less than 100w, the insoluble content of the final product is less than 0.01%, the production efficiency is improved, and the drying cost is reduced; in the reaction process in the embodiment, the temperature is controlled to be 82 ℃ at most, the reaction is ensured to be carried out stably, the colloid strength is improved, the good forming and quality of the colloid are ensured, and the continuous production is realized; in addition, the preparation method can be used for preparing solid products with the molecular weight of below 100w, the product types and the application range of the polyacrylamide are widened, the preparation method is simple, the highest temperature is lower than 100 ℃, and the harm to equipment and production environment is low.
The preparation method of the embodiment prepares the polyacrylamide colloid with the polymer concentration of 50-65 wt% by a segmented initiation polymerization mode combining redox initiation and ultraviolet initiation, solves the problems of large heat release, high temperature, large colloid viscosity, difficulty in continuous production and the like caused by increasing the monomer concentration in the production process of solid polyacrylamide products, and is particularly suitable for preparing products with molecular weight of less than 100w, such as dispersing agents, dry strength agents, filtrate reducer, flocculating agents, scale inhibitors, thickening agents and the like. The method provided by the embodiment has high production efficiency, stable colloidal property and high solid content, and is beneficial to improving the production efficiency in the industrial production process.
Example 2: in this example, the preparation method of the high-concentration polyacrylamide gel in example 1 was verified by experimental data of specific values:
firstly, preparing a polymerization solution according to the contents in the first step to the third step, adding 238.3g of a high-activity monomer acrylamide solution with the mass fraction of 50%, 30.8g of a high-activity monomer acryloyloxyethyl trimethyl ammonium chloride with the mass fraction of 80%, 12.6g of a terrestrial spark monomer dimethylamino propyl methacrylamide, 0.2g of a chain transfer agent sodium formate, 3g of polar oligomer PEG-800, 0.1g of a chelating agent sodium pentaacetate ethylene diamine tetracetate and 5g of deionized water into a reaction kettle, and uniformly stirring and dissolving; adding a photoinitiator and an azo initiator into the reaction kettle, wherein the photoinitiator is preferably 0.15g of Darocur 1173 solution with the concentration of 1 wt%, namely 2-hydroxy-2-methyl-1-phenyl-1-acetone, the azo initiator is preferably 0.2g of VA-044 solution with the concentration of 1 wt%, namely azobisisobutylimidazoline hydrochloride, and 0.1g of V-50 solution with the concentration of 1 wt%, namely azobisisobutylamidine dihydrochloride, stirring and mixing uniformly, and then adjusting the pH value of the polymerization solution to 4.5 by using sulfuric acid;
then, controlling the solution temperature of the polymerization solution after adjusting the pH value by water bath at 10 ℃, starting to introduce nitrogen to remove oxygen, introducing nitrogen for 20min, then adding an oxidant solution, continuing to introduce nitrogen for 2min, and then adding a reducing agent solution, wherein the oxidant solution is preferably a tert-butyl hydroperoxide solution with a concentration of 6g and a concentration of 10 wt%, and the reducing agent solution is preferably a sodium bisulfite solution with a concentration of 6g and a concentration of 10 wt%; stopping introducing nitrogen after the polymerization liquid is sticky, standing for 1h for prepolymerization reaction, wherein the highest temperature in the prepolymerization reaction process is 84.3 ℃, naturally cooling after the highest temperature is 84.3 ℃, and then placing the reaction kettle under ultraviolet light for light irradiation for 1 h; finally, the prepared colloid is taken out, and cationic polyacrylamide solid powder with the molecular weight of 42.8 ten thousand and the content of insoluble substances of less than 0.01 percent is obtained after granulation, drying, crushing and screening.
The experimental data in this example show that, by using the preparation method of example 1, the monomer concentration is 50-65 wt% to prepare the high-concentration polyacrylamide gel, which can obtain the final product with the molecular weight less than 100w, and the insoluble content of the final product is less than 0.01%, so that the production efficiency is improved, and the drying cost is reduced; in the reaction process in the embodiment, the temperature is controlled to be 84.3 ℃ at most, the reaction is ensured to be carried out stably, the colloid strength is improved, the good forming and quality of the colloid are ensured, and the continuous production is realized; in addition, the preparation method can be used for preparing solid products with the molecular weight of below 100w, the product types and the application range of the polyacrylamide are widened, the preparation method is simple, the highest temperature is lower than 100 ℃, and the harm to equipment and production environment is low.
The preparation method of the embodiment prepares the polyacrylamide colloid with the polymer concentration of 50-65 wt% by a segmented initiation polymerization mode combining redox initiation and ultraviolet initiation, solves the problems of large heat release, high temperature, large colloid viscosity, difficulty in continuous production and the like caused by increasing the monomer concentration in the production process of solid polyacrylamide products, and is particularly suitable for preparing products with molecular weight of less than 100w, such as dispersing agents, dry strength agents, filtrate reducer, flocculating agents, scale inhibitors, thickening agents and the like. The method provided by the embodiment has high production efficiency, stable colloidal property and high solid content, and is beneficial to improving the production efficiency in the industrial production process.
Example 3: in this example, the preparation method of the high-concentration polyacrylamide gel in example 1 was verified by experimental data of specific values:
firstly, adding 238.3g of high-activity monomer acrylamide solution with the mass fraction of 50% and 28.8g of high-activity monomer acrylic acid with the mass fraction of 70% into a reaction kettle, then adding 36.7g of low-activity monomer dimethylamino propyl methacrylamide, and neutralizing by using 32 wt% of sodium hydroxide, and simultaneously controlling the temperature of the system to be less than 10 ℃; then adding 0.6g of chain transfer agent sodium gluconate, 3g of small molecular compound urea, 3g of small molecular compound sodium chloride, 0.001g of reactive cross-linking agent N-hydroxymethyl acrylamide, 0.1g of chelating agent pentasodium ethylene diamine tetraacetate and 8g of deionized water into the reaction kettle, and stirring and dissolving uniformly; adding a photoinitiator and an azo initiator into the reaction kettle, wherein the photoinitiator is preferably 0.2g of Darocur 1173 solution with the concentration of 1 wt%, namely 2-hydroxy-2-methyl-1-phenyl-1-acetone, the azo initiator is preferably 0.1g of VA-044 solution with the concentration of 1 wt%, namely azobisisobutylimidazoline hydrochloride, and 0.2g of V-50 solution with the concentration of 1 wt%, namely azobisisobutylamidine dihydrochloride, stirring and mixing uniformly, and then adjusting the pH value of the polymerization solution to 5.8 by using sulfuric acid;
then, controlling the solution temperature of the polymerization solution after adjusting the pH value by a water bath to be 5 ℃, starting to introduce nitrogen to remove oxygen, introducing nitrogen for 20min, then adding an oxidant solution, continuing to introduce nitrogen for 2min, and then adding a reducing agent solution, wherein the oxidant solution is preferably 10g of tert-butyl hydroperoxide solution with the concentration of 10 wt%, and the reducing agent solution is preferably 10g of sodium bisulfite solution with the concentration of 10 wt%; stopping introducing nitrogen after the polymerization liquid is sticky, standing for 1h for prepolymerization reaction, wherein the highest temperature in the prepolymerization reaction process is 80.6 ℃, the reaction kettle is naturally cooled after the highest temperature is 84.3 ℃, and then the reaction kettle is irradiated for 1h under ultraviolet light; finally, the prepared colloid is taken out, and is granulated, dried, crushed and screened to obtain anionic polyacrylamide solid powder with the molecular weight of 50.1 ten thousand and the content of insoluble substances of less than 0.01 percent.
The experimental data in this example show that, by using the preparation method of example 1, the monomer concentration is 50-65 wt% to prepare the high-concentration polyacrylamide gel, which can obtain the final product with the molecular weight less than 100w, and the insoluble content of the final product is less than 0.01%, so that the production efficiency is improved, and the drying cost is reduced; in the reaction process in the embodiment, the temperature is controlled to be 80.6 ℃ at most, the reaction is ensured to be carried out stably, the colloid strength is improved, the good forming and quality of the colloid are ensured, and the continuous production is realized; in addition, the preparation method can be used for preparing solid products with the molecular weight of below 100w, the product types and the application range of the polyacrylamide are widened, the preparation method is simple, the highest temperature is lower than 100 ℃, and the harm to equipment and production environment is low.
The preparation method of the embodiment prepares the polyacrylamide colloid with the polymer concentration of 50-65 wt% by a segmented initiation polymerization mode combining redox initiation and ultraviolet initiation, solves the problems of large heat release, high temperature, large colloid viscosity, difficulty in continuous production and the like caused by increasing the monomer concentration in the production process of solid polyacrylamide products, and is particularly suitable for preparing products with molecular weight of less than 100w, such as dispersing agents, dry strength agents, filtrate reducer, flocculating agents, scale inhibitors, thickening agents and the like. The method provided by the embodiment has high production efficiency, stable colloidal property and high solid content, and is beneficial to improving the production efficiency in the industrial production process.
As noted above, while the present invention has been shown and described with reference to certain preferred embodiments, it is not to be construed as limited thereto. Various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (10)

1. The preparation method of the high-concentration polyacrylamide colloid is characterized by comprising the following steps of:
preparing acrylamide and a comonomer into an aqueous solution;
step two, adding a chain transfer agent, a chelating agent, a colloid reinforcing agent, a photoinitiator and an azo initiator into the aqueous solution prepared in the step one, and uniformly mixing to form a polymerization solution:
step three, controlling the height of the polymerization solution in the step two, adjusting the pH value of the polymerization solution, and adding an oxidant solution and a reducing agent solution after deoxygenation to perform prepolymerization reaction;
and step four, placing the prepolymer after the prepolymerization reaction in step three into ultraviolet light for illumination, and curing to obtain the high-concentration polyacrylamide colloid.
2. The method for preparing high-concentration polyacrylamide gel according to claim 1, wherein the mass concentration of each component in the prepolymerization reaction of the polymerization solution in the third step is as follows: 25-40 wt% of acrylamide, 5-30 wt% of comonomer, 0.01-0.1 wt% of chain transfer agent, 0.001-0.02 wt% of chelating agent, 1-7 wt% of colloid reinforcing agent, 1-10ppm of photoinitiator, 5-20ppm of azo initiator, 1-5 wt% of oxidant solution and 1-5 wt% of reducing agent solution.
3. The method for preparing high concentration polyacrylamide gel according to claim 1, wherein the polymerization liquid in step three is added with water to adjust the height of the polymerization liquid to 4-6 cm; the pH value of the polymerization solution is adjusted to 2-8.
4. The method for preparing high-concentration polyacrylamide colloid according to claim 3, wherein the pH value in the third step is adjusted to 2-8 by sulfuric acid or sodium hydroxide, nitrogen is introduced into the polymerization solution to remove oxygen, the mass concentration of the oxidant solution is 5-20 wt%, and the mass concentration of the reducing agent solution is 5-20 wt%.
5. The method for preparing high concentration polyacrylamide gel as claimed in claim 1, wherein in step one, acrylamide and comonomer are prepared into aqueous solution with monomer concentration of 50-65 wt%, and the monomer concentration of 50-65 wt% is formed by combining monomers with different activities, wherein the ratio of acrylamide content in total monomer mass is 50-80 wt%.
6. The method as claimed in claim 1, wherein the colloid strengthening agent comprises one or more of a reactive cross-linking agent, a non-reactive solid content-increasing small molecule compound, and a non-reactive hydrogen bonding-increasing polar oligomer.
7. The method for preparing high concentration polyacrylamide gel according to claim 6, wherein the reactive cross-linking agent comprises one or more of N, N-methylenebisacrylamide, N-methylolacrylamide, polyallylamine; the small molecular compound comprises one or more of urea, sodium chloride, ammonium sulfate, acetamide, ammonium adipate and ammonium chloride; the polar oligomer comprises one or more of polyoxyethylene with molecular weight less than 10000, polyvinyl alcohol and polyamine.
8. The method for preparing high concentration polyacrylamide gel according to claim 1, wherein the prepolymerization reaction process in the third step is carried out in an open place with heat exchange with the outside, the maximum temperature is less than 85 ℃, after the maximum temperature is reached, the temperature is naturally reduced for 0.5-1h, and then the product is irradiated in the ultraviolet light irradiation area in the fourth step.
9. The method for preparing high concentration polyacrylamide gel according to claim 8, wherein the prepolymerization reaction time in the third step is 1-2h, the natural cooling time is included in the prepolymerization reaction time, the prepolymer is irradiated under ultraviolet light for 0.5-2h, and the high concentration polyacrylamide gel with molecular weight below 100w is obtained after curing.
10. The product prepared by the preparation method of any one of claims 1 to 9, wherein the prepared product comprises the preparation of solid dispersing agent with molecular weight less than or equal to 100w, dry strength agent, fluid loss agent, flocculating agent, scale inhibitor and thickening agent.
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CN115677924A (en) * 2022-12-30 2023-02-03 江苏富淼科技股份有限公司 Low-molecular-weight polyacrylamide colloidal particle and preparation method thereof

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