A pipeline anticorrosion and heat preservation coating, a preparation method thereof and application thereof in a pipeline

Abstract

The application relates to the technical field of pipelines, and discloses a pipeline anticorrosive and heat-insulating coating, a preparation method thereof and application in pipelines. The pipeline anticorrosive and heat-insulating coating comprises the following raw materials in parts by weight: polystyrene 40-60 parts, silane modified starch 30-55 parts, calcium silicate 20-35 parts, hydroxyapatite 18-30 parts and a crosslinking agent 3-5 parts; wherein the silane modified starch is prepared from silane and starch, and the weight ratio of the silane to the starch is (0.08-0.2):1. The pipeline anticorrosive and heat-insulating coating prepared by the application has good heat-insulating performance, excellent corrosion resistance and high strength.

Description

A pipeline anti-corrosion and thermal insulation coating, its preparation method and its application in pipelines Technical Field

[0001] This application relates to the field of pipeline technology, and in particular to a pipeline anti-corrosion and thermal insulation coating, its preparation method, and its application in pipelines. Background Technology

[0002] Thermal insulation and corrosion resistant coatings are a special type of coating mainly used for thermal insulation and corrosion protection of equipment such as pipelines and storage tanks. They can maintain stable corrosion protection and thermal insulation performance in harsh environments, thus extending the service life of the equipment.

[0003] Corrosion-resistant and heat-insulating pipelines for factory buildings are mainly used in chemical process pipeline systems, including pipelines that transport chemical liquids, gases, corrosive media, etc. These pipelines usually need to have corrosion resistance to ensure the safe transport of media and the long-term stable operation of the pipelines. They also need to meet the requirements of pipeline systems for industrial equipment, such as boilers, kilns, cooling towers, etc. These pipelines usually need to have high temperature resistance and corrosion resistance to ensure the normal operation and safety of the equipment.

[0004] Currently, metal pipes are generally used in chemical pipeline systems. While metal pipes have good strength, they have poor corrosion resistance and high maintenance costs. Plastic pipes, on the other hand, have good corrosion resistance, but they have poor strength and are prone to cracking when subjected to impact.

[0005] Therefore, there is an urgent need to develop a pipeline anti-corrosion and thermal insulation coating with excellent corrosion resistance and thermal insulation performance. Summary of the Invention

[0006] In order to solve at least one of the above-mentioned technical problems and to develop a pipeline anti-corrosion and thermal insulation coating with excellent corrosion resistance and thermal insulation performance, this application provides a pipeline anti-corrosion and thermal insulation coating, its preparation method and its application in pipelines.

[0007] On the one hand, the pipeline anti-corrosion and heat insulation coating provided in this application includes the following raw materials in parts by weight: 40-60 parts of polystyrene, 30-55 parts of silane-modified starch, 20-35 parts of calcium silicate, 18-30 parts of hydroxyapatite, and 3-5 parts of crosslinking agent.

[0008] The silane-modified starch is prepared by using silane and starch, wherein the weight ratio of silane to starch is (0.08-0.2):1.

[0009] By adopting the above technical solution, the pipeline anti-corrosion and thermal insulation coating prepared in this application has excellent comprehensive performance, good thermal insulation performance, excellent corrosion resistance, and high strength.

[0010] This application employs a polystyrene and silane-modified starch crosslinking system to form a dense network crosslinking structure, which greatly improves the overall performance of the pipeline anti-corrosion and thermal insulation coating. Polystyrene possesses excellent thermal insulation properties, increasing the coating's heat insulation performance, reducing heat conduction and radiation, and exhibits excellent corrosion resistance, not easily absorbing moisture and chemicals, effectively preventing corrosion and damage to the coating surface. Silane-modified starch has a low thermal conductivity, effectively reducing heat conduction and thus improving the coating's thermal insulation effect. It also possesses good corrosion resistance and moisture resistance, effectively preventing the erosion of moisture and chemicals, thereby reducing corrosion and damage to the coating surface.

[0011] This application uses calcium silicate and hydroxyapatite as fillers. Calcium silicate and hydroxyapatite can reduce heat conduction and also hinder the penetration of moisture and chemicals, thereby reducing corrosion and damage to the coating surface. They also fill the tiny pores in the coating, making the prepared network structure more compact and the prepared coating having better thermal insulation and anti-corrosion properties.

[0012] Optionally, the weight ratio of the polystyrene to the silane-modified starch is (1-1.4):1.

[0013] By adopting the above technical solution, this application selects a better ratio of polystyrene and silane-modified starch, resulting in a denser network structure and a more superior overall performance of the prepared pipeline anti-corrosion and thermal insulation coating.

[0014] Optionally, the weight ratio of the calcium silicate to the hydroxyapatite is (0.8-1.2):1.

[0015] By adopting the above technical solution, this application uses a better ratio of calcium silicate and hydroxyapatite, which can better fill the network gaps and form a denser network structure, making the overall performance of the prepared pipeline anti-corrosion and heat insulation coating more excellent.

[0016] Optionally, the polystyrene is branched polystyrene, which is prepared from polystyrene, dichloromethane, benzoyl peroxide and sorbitol, wherein the weight ratio of the polystyrene, dichloromethane, benzoyl peroxide and sorbitol is 1:(0.02-0.12):(0.1-0.2):(0.3-0.6).

[0017] By adopting the above technical solution, this application selects branched polystyrene, which has more branched chain structures and can form a denser network structure with silane-modified starch.

[0018] Optionally, the average particle size of the polystyrene is not greater than 300 nm.

[0019] By adopting the above technical solution, this application uses a better polystyrene particle size. The nano-sized polystyrene particles have a smaller size and a larger specific surface area, resulting in better dispersion performance. They can better form a dense network structure with silane-modified starch, reduce heat conduction, better fill the micropores of the coating, and reduce corrosion and damage to the coating surface.

[0020] Optionally, the calcium silicate is microporous calcium silicate, and the specific surface area of ​​the microporous calcium silicate is 280-450 m². 2 / g, wherein the average particle size of the microporous calcium silicate is no greater than 200nm.

[0021] By adopting the above technical solution, the nano-sized microporous calcium silicate used in this application has a high specific surface area and a porous structure. Its porous structure can provide more surface area and active sites, increase the physical and chemical adsorption force between the coating and the substrate, thereby improving the adhesion and durability of the coating; and fill the micropores and cracks in the coating, enhancing the sealing and anti-peeling properties of the coating; and can form a microporous heat insulation layer in the coating, reducing heat conduction, resisting the corrosion of chemicals such as acids and alkalis, and further enhancing the anti-corrosion performance of the coating.

[0022] Optionally, the specific surface area of ​​the hydroxyapatite is 150-240 m². 2 / g, with an average particle size of no more than 200nm.

[0023] By adopting the above technical solution, the nano-sized hydroxyapatite used in this application can enhance the mechanical strength and durability of the coating. Its high specific surface area and porous structure can provide more surface active sites, increase the physical and chemical adsorption force between the coating and the substrate, thereby improving the adhesion and durability of the coating; and reduce heat conduction, thereby improving the thermal insulation performance of the coating and reducing heat loss. Nano-sized hydroxyapatite can also absorb and store heat and release it when needed, further improving the thermal insulation effect of the coating, as well as adsorb and store moisture and harmful substances, blocking their penetration into the coating surface, thereby reducing the corrosion and damage of the coating.

[0024] Optionally, the silane is one or more of triethoxysilane or trimethoxysilane.

[0025] Secondly, this application provides a method for preparing a pipeline anti-corrosion and thermal insulation coating, comprising the following steps:

[0026] S1. Mix and stir polystyrene, silane-modified starch and crosslinking agent, heat to 100-150℃, react for 2-4 hours, and prepare emulsion for later use.

[0027] S2. Add calcium silicate and hydroxyapatite to the emulsion and mix and stir for 4-6 hours to prepare a pipeline anti-corrosion and heat-insulating coating.

[0028] By adopting the above technical solution, the preparation method of the pipeline anti-corrosion and thermal insulation coating of this application is simple to operate, can be industrialized, and the prepared pipeline anti-corrosion and thermal insulation coating has excellent comprehensive performance.

[0029] Thirdly, this application provides a pipe, including a metal pipe body and a coating disposed on the surface of the metal pipe body, the coating being made of a pipe anti-corrosion and heat-insulating coating.

[0030] By adopting the above technical solution, the coating of the pipeline in this application is made of pipeline anti-corrosion and heat insulation coating, and the resulting pipeline has excellent anti-corrosion and heat insulation performance, which reduces the cost of frequent pipeline maintenance and increases production revenue.

[0031] In summary, the present invention has at least one of the following beneficial technical effects:

[0032] 1. By adopting the above technical solution, the pipeline anti-corrosion and thermal insulation coating prepared in this application has excellent comprehensive performance, good thermal insulation performance, and excellent corrosion resistance.

[0033] 2. This application uses a polystyrene and silane-modified starch crosslinking system to form a dense network crosslinking structure, which greatly improves the comprehensive performance of pipeline anti-corrosion and thermal insulation coatings;

[0034] 3. This application uses calcium silicate and hydroxyapatite as fillers. Calcium silicate and hydroxyapatite can reduce heat conduction and also hinder the penetration of moisture and chemicals, thereby reducing corrosion and damage to the coating surface. They also fill the tiny pores in the coating, making the prepared network structure more compact and the prepared coating more effective in terms of heat insulation and corrosion resistance.

[0035] 4. The preparation method of the pipeline anti-corrosion and thermal insulation coating of this application is simple to operate, can be industrialized, and the prepared pipeline anti-corrosion and thermal insulation coating has excellent comprehensive performance. Detailed Implementation

[0036] The present application will be further described in detail below with reference to the embodiments.

[0037] This application designs a pipeline anti-corrosion and heat insulation coating provided by this application, comprising the following raw materials in parts by weight: 40-60 parts of polystyrene, 30-55 parts of silane-modified starch, 20-35 parts of calcium silicate, 18-30 parts of hydroxyapatite, and 3-5 parts of crosslinking agent.

[0038] The silane-modified starch is prepared by using silane and starch, wherein the weight ratio of silane to starch is (0.08-0.2):1.

[0039] This application provides a method for preparing a pipeline anti-corrosion and thermal insulation coating, comprising the following steps:

[0040] S1. Mix and stir polystyrene, silane-modified starch and crosslinking agent, heat to 100-150℃, react for 2-4 hours, and prepare emulsion for later use.

[0041] S2. Add calcium silicate and hydroxyapatite to the emulsion and mix and stir for 4-6 hours to prepare a pipeline anti-corrosion and heat-insulating coating.

[0042] This application provides a pipe, including a metal pipe body and a coating disposed on the surface of the metal pipe body, the coating being made of a pipe anti-corrosion and heat-insulating coating.

[0043]

[0044] The raw materials used in this application are as follows. Unless otherwise specified, all raw materials used in this application are commercially available:

[0045] Polystyrene: Shanghai Huzhen Industrial Co., Ltd., 99% purity;

[0046] Starch: Wuhan Xingzhongcheng Technology Co., Ltd., corn starch, 99% purity;

[0047] Calcium silicate: 99% purity;

[0048] Hydroxyapatite: 98% purity;

[0049] Crosslinking agent: Benzoyl peroxide, Nanjing Chemical Reagent Co., Ltd., purity 98%;

[0050] Dichloromethane: Shandong Qiyuan Chemical Co., Ltd., purity 99.9%;

[0051] Benzoyl peroxide: Nanjing Chemical Reagent Co., Ltd., purity 98%;

[0052] Sorbitol: Shandong Zhengxing New Materials Co., Ltd., purity 99%;

[0053] Triethoxysilane: Henan Weitixi Chemical Technology Co., Ltd., purity 98%;

[0054] Trimethoxysilane: Henan Weitixi Chemical Technology Co., Ltd., purity 98%.

[0055] Testing items and methods:

[0056] The water resistance of the coating was tested according to the boiling water test method in GB / T 1733-1993 "Determination of Water Resistance of Coating Film".

[0057] The chemical resistance of the coating was tested according to the heated salt water resistance method in GB1763-1979 "Determination of Chemical Resistance of Coatings".

[0058] The alkali resistance of the coating was tested according to GB / T 9265-2009 "Determination of Alkali Resistance of Architectural Coatings".

[0059] The hardness of the coating was tested according to GB / T3398.2-2008 "Determination of Hardness of Plastics - Part 2: Rockwell Hardness";

[0060] The thermal conductivity of the coating was tested according to GB / T 10801.1-2021 "Polystyrene Foam Plastics for Thermal Insulation".

[0061] Examples 1-3

[0062] The dosage of anti-corrosion and heat-insulating coatings for pipelines in Examples 1-3 is shown in Table 1.

[0063] Table 1

[0064]

[0065] The polystyrene has an average particle size of 300 nm (the selected polystyrene was ground to obtain polystyrene with an average particle size of 300 nm), and the calcium silicate has a specific surface area of ​​280 m². 2 / g, with an average particle size of 200nm, and a specific surface area of ​​hydroxyapatite of 150m². 2 / g, with an average particle size of 200nm.

[0066] Example 1

[0067] A method for preparing a pipeline anti-corrosion and thermal insulation coating includes the following steps:

[0068] S1. Mix and stir polystyrene, silane-modified starch and crosslinking agent, heat to 100°C, react for 2 hours, and prepare emulsion for later use.

[0069] S2. Add calcium silicate and hydroxyapatite to the emulsion and mix and stir for 4 hours to prepare a pipeline anti-corrosion and heat insulation coating.

[0070] The preparation method of silane-modified starch is as follows: starch is added to ethanol and stirred evenly. Triethoxysilane is added and hydrochloric acid is added for catalysis. The mixture is stirred and stirred continuously. After reacting at 80°C for 3 hours, the mixture is filtered, washed and dried to obtain silane-modified starch. The weight ratio of silane to starch is 0.08:1. The amount of ethanol used is twice the amount of starch used, and the amount of hydrochloric acid used is 0.3 times the amount of starch used.

[0071] Example 2

[0072] A method for preparing a pipeline anti-corrosion and thermal insulation coating includes the following steps:

[0073] S1. Mix and stir polystyrene, silane-modified starch and crosslinking agent, heat to 120°C, react for 3 hours, and prepare emulsion for later use.

[0074] S2. Add calcium silicate and hydroxyapatite to the emulsion and mix and stir for 5 hours to prepare a pipeline anti-corrosion and heat insulation coating.

[0075] The preparation method of silane-modified starch is as follows: starch is added to ethanol and stirred evenly. Trimethoxysilane is added, followed by hydrochloric acid for catalysis. The mixture is stirred and stirred continuously. After reacting at 80°C for 3 hours, the starch is filtered, washed, and dried to obtain silane-modified starch. The weight ratio of silane to starch is 0.15:1. The amount of ethanol used is twice the amount of starch used, and the amount of hydrochloric acid used is 0.3 times the amount of starch used.

[0076] Example 3

[0077] A method for preparing a pipeline anti-corrosion and thermal insulation coating includes the following steps:

[0078] S1. Mix and stir polystyrene, silane-modified starch and crosslinking agent, heat to 150°C, react for 4 hours, and prepare emulsion for later use.

[0079] S2. Add calcium silicate and hydroxyapatite to the emulsion and mix and stir for 6 hours to prepare a pipeline anti-corrosion and heat insulation coating.

[0080] The preparation method of silane-modified starch is as follows: starch is added to ethanol and stirred evenly. Silanes, namely triethoxysilane and trimethoxysilane, are added. Hydrochloric acid is then added for catalysis. The mixture is stirred and stirred continuously. After reacting at 80°C for 3 hours, the mixture is filtered, washed, and dried to obtain silane-modified starch. The weight ratio of silane to starch is 0.2:1, the amount of ethanol is twice the amount of starch, the amount of hydrochloric acid is 0.3 times the amount of starch, and the weight ratio of triethoxysilane to trimethoxysilane is 1:1.

[0081] Comparative Example 1

[0082] Based on Example 3, except that an equal amount of starch is used to replace the silane-modified starch, the other components and preparation methods are the same as in Example 3.

[0083] Comparative Example 2

[0084] Based on Example 3, except that an equal amount of polystyrene was used to replace silane-modified starch, the other components and preparation methods were the same as in Example 3.

[0085] Comparative Example 3

[0086] Based on Example 3, except that an equal amount of hydroxyapatite was used to replace calcium silicate, the other components and preparation methods were the same as in Example 3.

[0087] Comparative Example 4

[0088] Based on Example 3, except that an equal amount of calcium silicate is used to replace hydroxyapatite, the other components and preparation methods are the same as in Example 3.

[0089] The performance of the pipeline anti-corrosion and thermal insulation coatings prepared in Examples 1-3 and Comparative Examples 1-4 was tested, and the test results are shown in Table 2.

[0090] Table 2

[0091]

[0092]

[0093] As can be seen from Examples 1-3 and Table 2, the pipeline anti-corrosion and thermal insulation coating prepared in this application has excellent comprehensive performance, good thermal insulation performance, excellent corrosion resistance, and high strength.

[0094] As can be seen from Comparative Examples 1-2, Example 3 and Table 2, the anti-corrosion and thermal insulation coating for pipelines prepared by silane-modified starch in this application has improved overall performance compared to the coating prepared by starch alone; and the cross-linked network structure formed by silane-modified starch and polystyrene increases the thermal insulation performance of the coating, reduces heat conduction and heat radiation, improves the thermal insulation effect of the coating, and has excellent corrosion resistance, which can effectively prevent corrosion and damage to the coating surface;

[0095] As can be seen from Comparative Examples 3-4, Example 3 and Table 2, the pipeline anti-corrosion and heat-insulating coating prepared by the present application using calcium silicate and hydroxyapatite composite material has better comprehensive performance. The composite of the two fills the tiny pores in the coating, making the prepared network structure more dense and the prepared coating has better heat insulation and anti-corrosion performance.

[0096] Examples 4-5

[0097] Based on Example 3, except for the different weight ratio of polystyrene and silane-modified starch, the other components and preparation methods are the same as in Example 3.

[0098] Example 4

[0099] The weight ratio of polystyrene to silane-modified starch is 1.2:1.

[0100] Example 5

[0101] The weight ratio of polystyrene to silane-modified starch is 1.4:1.

[0102] Examples 6-7

[0103] Based on Example 4, except for the different weight ratio of calcium silicate and hydroxyapatite, the other components and preparation methods are the same as in Example 4.

[0104] Example 6

[0105] The weight ratio of calcium silicate to hydroxyapatite is 0.8:1.

[0106] Example 7

[0107] The weight ratio of calcium silicate to hydroxyapatite is 1.2:1.

[0108] The performance of the pipeline anti-corrosion and thermal insulation coatings prepared in Examples 4-7 was tested, and the test results are shown in Table 3.

[0109] Table 3

[0110]

[0111] As can be seen from Examples 3-5 and Table 3, the present application selects a better weight ratio of polystyrene and silane-modified starch, resulting in a denser network structure and a more superior overall performance of the prepared pipeline anti-corrosion and thermal insulation coating.

[0112] As can be seen from Examples 4, 6-7 and Table 3, the present application uses a better ratio of calcium silicate and hydroxyapatite, which can better fill the network gaps and form a denser network structure, making the overall performance of the prepared pipeline anti-corrosion and thermal insulation coating more excellent.

[0113] Examples 8-10

[0114] Based on Example 4, except that an equal amount of branched polystyrene was used to replace polystyrene, the other components and preparation methods were the same as in Example 4.

[0115] Example 8

[0116] The weight ratio of polystyrene, dichloromethane, benzoyl peroxide and sorbitol is 1:0.02:0.1:0.3.

[0117] Example 9

[0118] The weight ratio of polystyrene, dichloromethane, benzoyl peroxide and sorbitol is 1:0.08:0.15:0.5.

[0119] Example 10

[0120] The weight ratio of polystyrene, dichloromethane, benzoyl peroxide and sorbitol is 1:0.12:0.2:0.6.

[0121] The performance of the pipeline anti-corrosion and thermal insulation coatings prepared in Examples 8-10 was tested, and the test results are shown in Table 4.

[0122] Table 4

[0123]

[0124] As can be seen from Examples 4, 8-10 and Table 4, the branched polystyrene selected in this application for preparing pipeline anti-corrosion and thermal insulation coatings has better overall performance. Branched polystyrene has more branched chain structures, which can form a denser network structure with silane-modified starch.

[0125] Examples 11-12

[0126] Based on Example 9, except for the average particle size of polystyrene, the other components and preparation methods are the same as in Example 9.

[0127] Example 11

[0128] The average particle size of polystyrene is 150 nm.

[0129] Example 12

[0130] The average particle size of polystyrene is 80 nm.

[0131] Examples 13-14

[0132] Based on Example 11, except for the specific surface area and average particle size of calcium silicate, the other components and preparation methods are the same as in Example 9.

[0133] Example 13

[0134] The specific surface area of ​​calcium silicate is 350 m². 2 / g, with an average particle size of 120nm.

[0135] Example 14

[0136] The specific surface area of ​​calcium silicate is 450 m². 2 / g, with an average particle size of 20nm.

[0137] Examples 15-16

[0138] Based on Example 13, except for the specific surface area and average particle size of hydroxyapatite, the other components and preparation methods are the same as in Example 13.

[0139] Example 15

[0140] The specific surface area of ​​hydroxyapatite is 200 m². 2 / g, with an average particle size of 120nm.

[0141] Example 16

[0142] The specific surface area of ​​hydroxyapatite is 240 m². 2 / g, with an average particle size of 20nm.

[0143] The performance of the pipeline anti-corrosion and thermal insulation coatings prepared in Examples 11-16 was tested, and the test results are shown in Table 5.

[0144] Table 5

[0145]

[0146]

[0147] As can be seen from Examples 9, 11-12 and Table 5, this application selects a better average particle size of polystyrene. The nano-sized polystyrene particles have a smaller size and a larger specific surface area, resulting in better dispersion performance. They can better form a dense network structure with silane-modified starch, reduce heat conduction, better fill the micropores of the coating, and reduce corrosion and damage to the coating surface, resulting in better overall performance.

[0148] As can be seen from Examples 11, 13-14 and Table 5, the superior nano-sized microporous calcium silicate adopted in this application has a high specific surface area and a porous structure. Its porous structure can provide more surface area and active sites, increase the physical and chemical adsorption force between the coating and the substrate, fill the micropores and cracks in the coating, and form a microporous heat insulation layer in the coating to reduce heat conduction. It can resist the corrosion of chemicals such as acids and alkalis, and further enhance the anti-corrosion and heat insulation properties of the coating.

[0149] As can be seen from Examples 13, 15-16 and Table 5, the use of superior nano-hydroxyapatite in this application can reduce heat conduction, improve the thermal insulation performance of the coating, and reduce heat loss. Nano-hydroxyapatite can also absorb and store heat and release it when needed, further improving the thermal insulation effect of the coating, as well as adsorb and store moisture and harmful substances, blocking their penetration into the coating surface, thereby reducing the corrosion and damage of the coating.

[0150] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the principles of this application should be covered within the scope of protection of this application.

Claims

1. A pipeline anti-corrosion and thermal insulation coating, characterized in that, It is made from the following raw materials in parts by weight: 40-60 parts polystyrene, 30-55 parts silane-modified starch, 20-35 parts calcium silicate, 18-30 parts hydroxyapatite, and 3-5 parts crosslinking agent; the preparation method of the silane-modified starch is as follows: starch is added to ethanol and stirred evenly, then triethoxysilane is added, followed by hydrochloric acid for catalysis, and the mixture is stirred continuously. After reacting at 80°C for 3 hours, the mixture is filtered, washed, and dried to obtain silane-modified starch; the weight ratio of silane to starch is (0.08-). 0.2):1; the silane is one or more of triethoxysilane or trimethoxysilane; the polystyrene is branched polystyrene; the average particle size of the polystyrene is not greater than 300 nm; the branched polystyrene is prepared from polystyrene, dichloromethane, benzoyl peroxide and sorbitol, and the weight ratio of the polystyrene, the dichloromethane, the benzoyl peroxide and the sorbitol is 1:(0.02-0.12):(0.1-0.2):(0.3-0.6).

2. The pipeline anti-corrosion and thermal insulation coating according to claim 1, characterized in that, The weight ratio of the polystyrene to the silane-modified starch is (1-1.4):

1.

3. The pipeline anti-corrosion and thermal insulation coating according to claim 1, characterized in that, The weight ratio of the calcium silicate to the hydroxyapatite is (0.8-1.2):

1.

4. The pipeline anti-corrosion and thermal insulation coating according to claim 1, characterized in that, The calcium silicate is microporous calcium silicate, and the specific surface area of ​​the microporous calcium silicate is 280-450 m². 2 / g, wherein the average particle size of the microporous calcium silicate is no greater than 200nm.

5. The pipeline anti-corrosion and thermal insulation coating according to claim 1, characterized in that, The specific surface area of ​​the hydroxyapatite is 150-240 m². 2 / g, with an average particle size of no more than 200nm.

6. A method for preparing the pipeline anti-corrosion and thermal insulation coating according to claim 1, characterized in that, Includes the following steps: S1. Mix and stir polystyrene, silane-modified starch and crosslinking agent, and heat to 100-150℃. After reacting for 2-4 hours, prepare an emulsion for later use. S2. Add calcium silicate and hydroxyapatite to the emulsion and mix and stir for 4-6 hours to prepare a pipeline anti-corrosion and heat-insulating coating.

7. A pipe, characterized in that, It includes a metal pipe body and a coating disposed on the surface of the metal pipe body, the coating being made of the pipe anti-corrosion and heat-insulating coating as described in claim 1.

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