CN116554375A - Nuclear-grade polyacrylic acid and preparation method and application thereof - Google Patents

Abstract

The application discloses a nuclear grade polyacrylic acid and its preparation method and application. A nuclear-grade polyacrylic acid, the molecular weight of the nuclear-grade polyacrylic acid is 100,000-200,000, and the sulfur content in the nuclear-grade polyacrylic acid is 500ppb-1000ppb. The nuclear-grade polyacrylic acid has controllable molecular weight, good polydispersity, excellent scale inhibition performance, excellent decomposition half-life, controllable molecular weight of 100,000-200,000, and polydispersity of 1.0-3.5; Simple; the preparation equipment is simple, the preparation efficiency is high, and the volume of the synthesis reaction kettle used in the preparation can be adjusted according to the output, which greatly improves the preparation efficiency; the preparation cost of the present invention is low, green, clean and pollution-free. The raw materials in the preparation process are cheap and easy to obtain, the involved reaction kettle only needs to consume a small amount of electric energy, a sulfur-free initiator is added, and alcohols and ethers related solvents cause less environmental pollution.

Description

A kind of nuclear grade polyacrylic acid and its preparation method and application

technical field

The application relates to a nuclear-grade polyacrylic acid and its preparation method and application, belonging to the technical field of scale inhibitor preparation.

Background technique

Scale inhibitors can effectively inhibit the formation of scaling because of their chelating, dispersing, and lattice distortion effects on scales, making them widely used in seawater desalination, water circulation systems, and other fields. Currently, the types of scale inhibitors represented by natural polymer scale inhibitors, inorganic phosphate scale inhibitors, organic phosphonate scale inhibitors and environmentally friendly scale inhibitors have been widely promoted and accepted in actual industrial production. application. Among the above-mentioned antiscalants, natural polymer antiscalants and environment-friendly antiscalants have become ideal materials for antiscalants because of their relatively small pollution to the environment.

Among the environmentally friendly antiscalant materials, polyaspartic acid (PASP), polyepoxysuccinic acid (PESA), acrylic acid (AA) and their derivatives have become research hotspots in recent years. Among them, when the concentration of PASP is 3 mg/L, the scale inhibition rate of Ca ²⁺ reaches 80%; when the concentration of PESP with hyperbranched structure is 15 mg/L, the scale inhibition rate of calcium carbonate reaches 90%; the concentration of AA is At a dose of 8mg/L, the inhibition rate to calcium carbonate is 80%. Using AA as a monomer, polyacrylic acid polymerized has regular molecular chains, and has the characteristics of cost-effectiveness, and has attracted extensive attention in the application field of industrial circulating cooling water systems. In particular, many components in the secondary circuit system of the PWR nuclear power plant, such as condensers, feed water heaters, steam-water separation reheaters, etc., are mainly made of carbon steel and are prone to corrosion during operation. The corrosion products produced by the corrosion of carbon steel equipment are transported with the feed water, and then deposited in the steam generator, which can lead to many serious and harmful consequences, such as heat energy loss, heat transfer tube corrosion, thermal hydraulic instability, power output reduction, etc. Therefore, controlling the deposition of corrosion products is a critical issue to ensure the performance and integrity of steam generators. In order to alleviate the fouling of steam generators caused by the deposition of corrosion products, nuclear power plants at home and abroad have adopted various strategies. Among them, polyacrylic acid dispersants have been used in more than 20 pressurized water reactor units in the United States and other countries. Tested under the condition of starting up, all showed remarkable descaling effect.

At present, among the polyacrylic acid materials that have been reported in China, they are mainly divided into two categories:

(1) Using polyacrylic acid as the matrix, carry out related improvement and application expansion on the synthesis process. For example, the method for preparing polyacrylic acid described in the patent CN1324057C uses the recovered heat medium to purify polyacrylic acid from the aqueous solution of acrylic acid or acrylic acid. This method effectively utilizes and recovers latent heat and provides a new idea for low-carbon production; another example is in the patent CN102858815B The polyacrylic acid (salt), polyacrylic acid (salt)-based water-absorbent resin and its manufacturing method provide a water-absorbent resin containing a tracer and its manufacturing method, as well as an identification method and a tracking method of the water-absorbent resin, The method can trace various problems in the manufacturing process, consumer use, and discarding process by checking the tracer; another example is the manufacturing method of polyacrylic acid (salt) series water-absorbing resin powder described in the patent CN104212105B, polyacrylic acid Acrylic acid (salt)-based water-absorbing resin powder, the resin powder provided has both liquid permeability and water absorption speed, and has a good application prospect; as described in the patent CN101921359B, polyacrylic acid or its copolymer and polyacrylate or its copolymer A method for preparing a compound salt. This method uses carbon-carbon unsaturated bonds and inorganic ingredients as raw materials to prepare organic polymers. It has the characteristics of less energy consumption, high equipment utilization rate, superior product performance, safety and environmental protection. It is used in dispersants and barriers. It has good application prospects in scale agent, thickener and flocculant.

(2) Surface modification of polyacrylic acid to prepare composite materials and related applications. As described in the patent CN107573446B, a boron nitride nanosheet and polyacrylic acid gel composite thermal interface material and its preparation method, the thermal interface material has excellent thermal conductivity, and can be closely attached to the surface of various heat dissipation components. It has attractive application prospects in the field of heat dissipation conduction of CPUs and relays. Another example is the preparation method of the polypyrrole/polyacrylic acid composite gel electrolyte described in the patent CN101714460B. Capacitors and other fields have good application prospects; as described in the patent CN101440151B, the wet polyurethane grafted polyacrylic acid copolymer resin for embossed leather and its preparation method, the synthetic leather made by this invention is easy to emboss, and the pattern is clear and full , Strong three-dimensional sense. Another example is the MWCNTs@polyacrylic acid@MOF-5 composite material and its preparation method described in the patent CN104689801B. The synthesized composite material has the characteristics of high specific surface area and good adsorption performance, and has a good application prospect in cigarette filters.

At the same time, the traditional polyacrylic acid synthesis method inevitably has problems such as long preparation period, low yield, cumbersome preparation process, harsh preparation conditions and the use of sulfur-containing initiators. However, in the actual nuclear power plant secondary circuit water environment, the content of sulfur and other elements is strictly controlled. At present, there are few domestic reports on the preparation of sulfur-free or low-sulfur polyacrylic acid and its application in the field of nuclear power. In addition, the molecular weight of polyacrylic acid has a significant impact on the scale inhibition effect, and there are few related reports on the influence of polyacrylic acid with different molecular weight levels on the scale inhibition performance. In particular, there are few reports on the preparation of low-sulfur and high-molecular-weight polyacrylic acid scale inhibitors and their application in the secondary loop of nuclear power plants.

Contents of the invention

According to one aspect of the present application, a nuclear grade polyacrylic acid is provided.

The molecular weight of the nuclear-grade polyacrylic acid is controllable, above 100,000 levels, with good polydispersity, excellent scale inhibition performance, excellent decomposition half-life, and the potential for industrial production. development value.

A nuclear-grade polyacrylic acid, the molecular weight of the nuclear-grade polyacrylic acid is 100,000-200,000, and the sulfur content in the nuclear-grade polyacrylic acid is 500ppb-1000ppb.

Optionally, the molecular weight of the nuclear-grade polyacrylic acid is independently selected from 100,000, 110,000, 120,000, 130,000, 140,000, 150,000, 160,000, 170,000, 180,000, 190,000, and 200,000 Any value or any range value in between.

Optionally, the sulfur content in the core-grade polyacrylic acid is independently selected from any value among 500ppb, 600ppb, 700ppb, 800ppb, 900ppb, 1000ppb or any range between them.

Optionally, the molecular weight of the nuclear-grade polyacrylic acid is 120,000-200,000.

Optionally, the polydispersity of the core-grade polyacrylic acid is 1.0-3.5.

Optionally, the polydispersity of the core grade polyacrylic acid is independently selected from 1.00, 1.50, 2.00, 2.10, 2.20, 2.30, 2.40, 2.48, 2.50, 2.60, 2.70, 2.80, 2.90, 3.00, 3.10, 3.20, Any value among 3.27, 3.30, 3.31, 3.40, 3.43, 3.50 or any range value between the two.

According to yet another aspect of the present application, a method for preparing nuclear-grade polyacrylic acid is provided.

The preparation cycle is short, the operation process is simple, and the required preparation cycle is basically controlled within 24 hours. The operation process only includes steps such as weighing, dissolving, mixing, heating, heat preservation, reaction, precipitation, and drying; the preparation equipment Simple, high preparation efficiency, the required equipment is glassware and reaction kettle commonly used in the laboratory, the volume of the synthesis reaction kettle used in the preparation can be adjusted according to the output, which greatly improves the preparation efficiency; the preparation cost is low, green, clean and non-toxic Pollution, the raw materials in the preparation process are cheap and easy to obtain, the involved reaction kettle only needs to consume a small amount of electric energy, adding sulfur-free initiators, alcohols and ethers related solvents have less environmental pollution.

A preparation method of nuclear grade polyacrylic acid, comprising the following steps:

The mixture containing acrylic acid monomer, initiator and organic solvent is mixed and reacted to obtain nuclear grade polyacrylic acid.

Optionally, the initiator is selected from at least one of dicumyl peroxide and hydrogen peroxide.

Optionally, the organic solvent is selected from at least one of ethylene glycol and isopropanol.

Optionally, the mass ratio of the organic solvent, the acrylic monomer, and the initiator is 100˜600:100:1.

Optionally, the mass ratio of organic solvent, acrylic acid monomer and initiator is independently selected from 100:100:1, 200:100:1, 300:100:1, 350:100:1, 400:100:1, Any value among 450:100:1, 500:100:1, 550:100:1, 600:100:1 or any range between them.

Optionally, the mixing time before the reaction is 0.5h-2.5h.

Optionally, the conditions of the reaction are as follows:

The temperature is 60℃～100℃;

The time is 4h～10h.

Optionally, the temperature is independently selected from 60°C, 65°C, 70°C, 75°C, 78°C, 80°C, 82°C, 85°C, 86°C, 88°C, 90°C, 92°C, 95°C, 100°C Any value in or any range in between.

Optionally, the time is independently selected from any value in 4h, 4.5h, 5h, 5.5h, 6h, 6.5h, 7h, 7.5h, 8h, 8.5h, 9h, 9.5h, 10h or between any two range of values.

Alternatively, the reaction is performed under inert gas.

Optionally, after the reaction, the product is mixed with ethylene glycol methyl ether.

Optionally, the mass ratio of product to ethylene glycol methyl ether is 1:3-5.

According to the third aspect of the present application, an application of nuclear-grade polyacrylic acid as a scale inhibitor is provided.

The scale inhibitor made of the above-mentioned nuclear grade polyacrylic acid has excellent scale inhibition performance and excellent decomposition half-life.

A nuclear-grade polyacrylic acid scale inhibitor, which is obtained by crushing the nuclear-grade polyacrylic acid to obtain a nuclear-grade polyacrylic acid scale inhibitor; the above-mentioned nuclear-grade polyacrylic acid is selected from the above-mentioned nuclear-grade polyacrylic acid and/or the above-mentioned The nuclear-grade polyacrylic acid obtained by the preparation method.

The beneficial effect that this application can produce comprises:

1) The nuclear-grade polyacrylic acid provided by this application has controllable molecular weight, good polydispersity, excellent scale inhibition performance, and excellent decomposition half-life. The molecular weight can be controlled at 100,000-200,000, and the polydispersity is 1.0-3.5.

2) The preparation period provided by the present application is short and the operation process is simple. The required preparation cycle is basically controlled within 24 hours, and the operation process only includes steps such as weighing, dissolving, mixing, heating, heat preservation, reaction, precipitation, and drying, which are simple and easy; the preparation equipment is simple and the preparation efficiency is high. The required equipment is glassware and reaction kettles commonly used in laboratories, and the volume of the synthesis reaction kettle used in the preparation can be adjusted according to the output, which greatly improves the production efficiency.

3) The preparation cost of the present invention is low, green, clean and pollution-free. The raw materials in the preparation process are cheap and easy to obtain, the involved reaction kettle only needs to consume a small amount of electric energy, a sulfur-free initiator is added, and alcohols and ethers related solvents cause less environmental pollution.

Description of drawings

Fig. 1 is the infrared spectrogram of polyacrylic acid in Example 1 of the present invention.

Fig. 2 is a scanning electron microscope image of polyacrylic acid in Example 1 of the present invention.

Fig. 3 is a picture of the scale inhibition performance of polyacrylic acid in Example 1 of the present invention.

Figure 4 is a summary picture of the molecular weight and dispersion of polyacrylic acid in Examples 1-5 of the present invention.

Detailed ways

The present application is described in detail below in conjunction with the examples, but the present application is not limited to these examples.

Unless otherwise specified, the raw materials in the examples of the present application were purchased through commercial channels.

Analytic method is as follows in the embodiment of the application:

Spectral analysis was performed using Fourier transform infrared spectroscopy.

Electron microscopy analysis was performed using a field emission scanning electron microscope.

The scale inhibition performance was analyzed by spectrophotometer.

Example 1

Weigh 200g of isopropanol, 100g of acrylic acid monomer, and 1g of dicumyl peroxide, and slowly add them into the reaction kettle and mix evenly for 0.5 hours. Under the protection of high-purity argon, slowly heat to 65°C and keep the temperature constant for 4 hours. Then, 50 g of the generated product was weighed and poured into 50 g of ethylene glycol methyl ether solvent, and polyacrylic acid solid was precipitated. Next, the precipitated polyacrylic acid was dried at 70° C. for 4 hours, then taken out and crushed, and then dried for 8 hours. Finally, the formed polyacrylic acid solid powder is the nuclear grade polyacrylic acid scale inhibitor.

Fig. 1 is the infrared spectrogram of polyacrylic acid in Example 1, and the characteristic peak positions in the spectrum correspond to the characteristic peaks of polyacrylic acid one by one, indicating that pure polyacrylic acid has been successfully prepared. Figure 2 is an optical micrograph of this embodiment. Figure 3 is a picture of the scale inhibition performance of Example 1, in which the scale inhibition test takes the common PWR nuclear power plant secondary circuit system of corrosion product oxide Fe ₃ O ₄ as an example, and investigates the dispersion effect of the polyacrylic acid developed and prepared by this patent on it .

Example 2

Weigh 300g of isopropanol, 100g of acrylic acid monomer, and 1g of dicumyl peroxide, and slowly add them into the reaction kettle and mix evenly for 1 hour. Under the protection of high-purity argon, slowly heat to 75°C and keep the temperature constant for 6 hours. Then, 50 g of the generated product was weighed and poured into 100 g of ethylene glycol methyl ether solvent, and polyacrylic acid solid was precipitated. Next, the precipitated polyacrylic acid was dried at 75° C. for 5 hours, then taken out and crushed, and then dried for another 7 hours. Finally, the formed polyacrylic acid solid powder is the nuclear grade polyacrylic acid scale inhibitor.

Example 3

Weigh 400g of isopropanol, 100g of acrylic acid monomer, and 1g of hydrogen peroxide, and slowly add them into the reaction kettle and mix uniformly for 1.5 hours. Under the protection of high-purity argon, slowly heat to 80°C and keep the temperature constant for 8 hours. Then, 50 g of the resulting product was weighed and poured into 150 g of ethylene glycol methyl ether solvent, and polyacrylic acid solid was precipitated. Next, the precipitated polyacrylic acid was dried at 80° C. for 6 hours, then taken out and crushed, and then dried for another 6 hours. Finally, the formed polyacrylic acid solid powder is the nuclear grade polyacrylic acid scale inhibitor.

Example 4

Weigh 500g of isopropanol, 100g of acrylic acid monomer, and 1g of dicumyl peroxide, and slowly add them into the reaction kettle and mix them uniformly for 2 hours. Under the protection of high-purity argon, slowly heat to 85°C and keep the temperature constant for 9 hours. Then, 50 g of the generated product was weighed and poured into 200 g of ethylene glycol methyl ether solvent, and polyacrylic acid solid was precipitated. Next, the precipitated polyacrylic acid was dried at 85° C. for 7 hours, then taken out and crushed, and then dried for 5 hours. Finally, the formed polyacrylic acid solid powder is the nuclear grade polyacrylic acid scale inhibitor.

Example 5

Weigh 600g of isopropanol, 100g of acrylic acid monomer, and 1g of hydrogen peroxide, and slowly add them into the reaction kettle and mix evenly for 2.5 hours. Under the protection of high-purity argon, slowly heat to 90°C and keep the temperature constant for 10 hours. Then, 50 g of the generated product was weighed and poured into 250 g of ethylene glycol methyl ether solvent, and polyacrylic acid solid was precipitated. Next, the precipitated polyacrylic acid was dried at 90° C. for 8 hours, then taken out and crushed, and then dried for another 4 hours. Finally, the formed polyacrylic acid solid powder is the nuclear grade polyacrylic acid scale inhibitor.

Figure 4 is a summary diagram of the molecular weight and dispersion of polyacrylic acid in Examples 1-5, from which it can be seen that the molecular weight distribution is 100,000-200,000, and the polydispersity is 1.0-3.5.

The above are only a few embodiments of the application, and do not limit the application in any form. Although the application is disclosed as above with preferred embodiments, it is not intended to limit the application. Any skilled person familiar with this field, Without departing from the scope of the technical solution of the present application, any changes or modifications made using the technical content disclosed above are equivalent to equivalent implementation cases, and all belong to the scope of the technical solution.

Claims (10)

1. A nuclear grade polyacrylic acid, characterized in that the molecular weight of the nuclear grade polyacrylic acid is 100,000 to 200,000, and the sulfur content in the nuclear grade polyacrylic acid is 500ppb to 1000ppb. 2. The nuclear-grade polyacrylic acid according to claim 1, wherein the molecular weight of the nuclear-grade polyacrylic acid is 120,000-200,000. 3. The nuclear-grade polyacrylic acid according to claim 1, characterized in that, the polydispersity of the nuclear-grade polyacrylic acid is 1.0-3.5. 4. a preparation method of nuclear grade polyacrylic acid, is characterized in that, comprises the following steps: The mixed liquid containing acrylic acid monomer, initiator and organic solvent is reacted to obtain nuclear grade polyacrylic acid. 5. preparation method according to claim 4, is characterized in that, described initiator is selected from at least one in hydrogen peroxide, dicumyl peroxide. 6. preparation method according to claim 4, is characterized in that, described organic solvent is selected from at least one in ethylene glycol, Virahol. 7. The preparation method according to claim 4, characterized in that the mass ratio of organic solvent, acrylic acid monomer and initiator is 100-600:100:1. 8. preparation method according to claim 4, is characterized in that, the condition of reaction is as follows: The temperature is 60℃～100℃; The time is 4h～10h. 9. The preparation method according to claim 4, characterized in that the reaction is carried out under an inert gas. 10. A nuclear-grade polyacrylic acid scale inhibitor, characterized in that, the nuclear-grade polyacrylic acid scale inhibitor is obtained after crushing the nuclear-grade polyacrylic acid; The aforementioned nuclear-grade polyacrylic acid is selected from the nuclear-grade polyacrylic acid described in any one of claims 1-3 and/or the nuclear-grade polyacrylic acid obtained by the preparation method described in any one of claims 4-9.