Corrosion-resistant material for double-oblique-wave packing tower

Abstract

The invention discloses an anti-corrosion material for a double-oblique-wave packing tower, belongs to the technical field of packing tower material processing, and aims to solve the technical problem that the corrosion resistance and the impact resistance of a packing tower material in the prior art need to be further improved. The modified polyvinyl chloride material specifically comprises the following components in parts by mass: 60-80 parts of modified polyvinyl chloride, 10-15 parts of a core-shell toughening agent, 5-8 parts of a modified filler and 10-12 parts of an auxiliary additive, the modified polyvinyl chloride, the core-shell toughening agent, the modified filler and the auxiliary additive are uniformly mixed, melt-extruded and granulated to obtain the corrosion-resistant material, so that not only is the corrosion resistance of the packed tower material improved, but also the mechanical strength of the packed tower material is improved.

Description

Technical Field

[0001] This invention relates to the field of packed tower material processing technology, specifically to an anti-corrosion material for a double-sloping wave water-spraying packed tower. Background Technology

[0002] With increasingly stringent industrial waste gas treatment and flue gas desulfurization processes, double-sloping wave water-spraying packed towers, as a highly efficient, low-resistance, and easy-to-clean gas-liquid contact device, have been widely used in industries such as metallurgy, power, and chemicals.

[0003] The structural design of this type of tower emphasizes the uniformity of water spraying and the stability of gas distribution in the packing area. During continuous operation, it is exposed to corrosive media such as SO2, HCl, and HF, as well as high temperature and high humidity environments, which places higher demands on the corrosion resistance of its internal components, especially the packing, spraying devices, and tower lining.

[0004] Currently, widely used anti-corrosion materials include polyvinyl chloride (PVC), polypropylene (PP), fiberglass, and polyvinylidene fluoride (PVDF). Among them, PVC is widely used in the construction of tower bodies, packing supports, and flow guiding structures due to its good acid resistance, formability, and cost advantages. To further improve its performance in complex flue gas environments, researchers have adopted various material modification methods, including blending modification, fluorination treatment, and the addition of nanofillers, to improve its heat resistance, mechanical strength, and chemical stability.

[0005] In the existing technology, although polyvinyl chloride (PVC) materials have good service life and cost-effectiveness in acidic gas-liquid systems, there are still shortcomings and defects in the high humidity, high temperature and multi-component corrosion environment of double-sloping wave water spraying packed tower. PVC is prone to deHCl reaction or microcrack deterioration in oxidizing atmosphere or strong corrosive environment containing sulfate ions and sulfite ions, which leads to a decrease in the impact resistance of the material surface, and gradual embrittlement, cracking or even perforation.

[0006] In addition, polyvinyl chloride itself has poor molecular chain flexibility and lacks functional group reactivity, resulting in poor toughness in applications and easy fatigue failure under alternating hot and cold conditions. At the same time, the introduction of nanofillers into polyvinyl chloride materials is widely used to improve its corrosion resistance. These nanoparticles can, to a certain extent, hinder the diffusion path of corrosive media and improve the corrosion resistance of materials.

[0007] However, due to the poor interfacial compatibility between nanofillers and polyvinyl chloride matrix, the fillers are prone to agglomeration or interfacial debonding in the matrix, forming stress concentration points or micro-defects, which leads to a decrease in the density and mechanical stability of the overall composite system. To address this, a solution is proposed. Summary of the Invention

[0008] The purpose of this invention is to provide an anti-corrosion material for double-sloping wave water-spraying packed towers, which solves the technical problem that the corrosion resistance and impact resistance of packed tower materials in the prior art need to be further improved.

[0009] The objective of this invention can be achieved through the following technical solution: a corrosion-resistant material for a double-sloping wave water-spraying packed tower, comprising the following components by mass: 60-80 parts modified polyvinyl chloride, 10-15 parts core-shell toughening agent, 5-8 parts modified packing and 10-12 parts auxiliary additives.

[0010] The auxiliary additive is composed of a dispersant, an antioxidant, and a lubricant in a mass ratio of 1:0.5:2. The dispersant is one or more of trioctyl phosphate, tris(2-ethylhexyl) phosphate, and diphenyl phosphate. The antioxidant is one or more of 4,4'-thiobis(6-tert-butyl-3-methylphenol), N,N'-diphenyl-p-phenylenediamine, and tris(2,4-di-tert-butylphenyl) phosphite. The lubricant is one or more of oleic acid, fatty acid amide, and oleic acid amide.

[0011] Furthermore, the modified polyvinyl chloride is prepared by the following steps:

[0012] A1. Add polyvinyl chloride powder and N,N-dimethylacetamide to a reaction vessel. Raise the temperature of the reaction vessel to 70-80℃ and keep it warm and stir for 1-2 hours. Then, add mixed amine solution dropwise to the reaction vessel and continue to keep it warm and stir for 3-4 hours. The modified polyvinyl chloride precursor is obtained by post-treatment.

[0013] The reaction formula for preparing the modified polyvinyl chloride precursor is as follows:

[0014]

[0015] The reaction principle for preparing modified polyvinyl chloride precursors is as follows:

[0016] During the reaction, under high temperature conditions, 5-hexen-1-amine and N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane undergo a crosslinking reaction with some of the chlorine groups on polyvinyl chloride to obtain a modified polyvinyl chloride precursor with modified olefin double bonds.

[0017] A2. Place the polyvinyl chloride precursor and 1,2-dichloroethane in a reaction vessel and stir. Cool the mixture to 0-5℃, add m-chloroperoxybenzoic acid, and keep it at the temperature for 6-8 hours. After post-treatment, the modified polyvinyl chloride is obtained.

[0018] The reaction formula for the preparation of modified polyvinyl chloride is:

[0019]

[0020] The preparation reaction principle of modified polyvinyl chloride is as follows:

[0021] During the reaction, at low temperature, the hydroxyl oxygen in the m-chloroperoxybenzoic acid molecule carries a partial positive charge due to the interaction of the electron-withdrawing chlorine atom and the peroxy bond, forming an electrophilic center. The π electron cloud of the olefin unsaturated double bond in the side chain of the polyvinyl chloride precursor attacks this positively charged oxygen, resulting in cis addition and forming a bicyclic transition state. In the transition state, the olefin double bond and the peroxy bond of m-chloroperoxybenzoic acid break together, and the oxygen atom is transferred to the carbon atom at the end of the double bond, forming a ternary epoxy structure, thus obtaining modified polyvinyl chloride.

[0022] Further, in step A1, the ratio of polyvinyl chloride powder, N,N-dimethylacetamide, and mixed amine solution is 5-8g:50-100mL:30-35mL. The mixed amine solution is obtained by mixing N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, 5-hexen-1-amine, and N,N-dimethylacetamide in a ratio of 6-8g:8-10g:200mL. The post-treatment includes the following steps: after the reaction is completed, the reaction system is cooled to room temperature, and the reaction solution is transferred to a rotary evaporator at a temperature of 80-100℃ for vacuum distillation until no liquid is collected. The modified polyvinyl chloride precursor is obtained. In step A2, the ratio of the polyvinyl chloride precursor, 1,2-dichloroethane, and m-chloroperoxybenzoic acid is 8-10g:100-150mL:0.5-1g. The post-treatment includes the following steps: after the reaction is completed, 20-30mL of saturated sodium bisulfite aqueous solution is added to the reaction solution to terminate the reaction. After the reaction system cools to room temperature, saturated sodium bicarbonate aqueous solution is added to adjust the pH to neutral. The system is allowed to stand and separate into layers. The organic phase is transferred to a rotary evaporator at a temperature of 80-90℃ and evaporated until no liquid is collected, thus obtaining the modified polyvinyl chloride.

[0023] Furthermore, the core-shell toughening agent is prepared by the following steps:

[0024] B1. Place sodium dodecyl sulfate, deionized water and potassium carbonate in a reaction vessel and stir for 10-15 min. Add butyl acrylate and dicyclopentadiene acrylate. Heat the reaction vessel to 70-80℃ and add potassium persulfate solution. Keep the reaction at this temperature for 1-2 h to obtain latex seeds.

[0025] The reaction principle for preparing latex seeds is as follows:

[0026] During the reaction, under the action of emulsifier and potassium carbonate, butyl acrylate and dicyclopentadiene acrylate undergo free radical polymerization under the initiation of potassium persulfate to obtain latex seeds. Dicyclopentadiene acrylate is a crosslinking agent with two sterically hindered unsaturated double bonds, which provide reaction sites for the next step of the reaction.

[0027] B2. Place latex seeds, sodium dodecyl sulfate, deionized water, and potassium persulfate solution in a reaction vessel and stir for 10-15 minutes. Heat the reaction vessel to 50-60°C, add styrene and acrylonitrile, and heat the reaction vessel to 70-80°C. Keep the reaction at this temperature for 1-2 hours. Post-treatment yields the core-shell toughening agent.

[0028] The preparation reaction principle of core-shell toughening agents is as follows:

[0029] During the reaction, under the initiation of emulsifier and potassium persulfate, styrene and acrylonitrile undergo free radical polymerization with the unsaturated double bonds left by the latex seeds, forming a polymer layer on the surface of the latex seeds, thus obtaining a core-shell toughening agent.

[0030] Further, in step B1, the ratio of sodium dodecyl sulfate, deionized water, potassium carbonate, butyl acrylate, dicyclopentadiene acrylate, and potassium persulfate solution is 0.5-1g:150-200mL:0.1-0.2g:8-10g:1-2g:2-4mL, and the potassium persulfate solution is a 15-20wt% aqueous solution. In step B2, the ratio of latex seeds, sodium dodecyl sulfate, deionized water, potassium persulfate solution, styrene, and acrylonitrile is 10-12g:0.1-0.2g:100-150mL:2-4mL:6-8g:2-4g, and the potassium persulfate solution is a 15-20wt% aqueous solution. The post-treatment includes the following steps: after the reaction is complete, wait for the reaction system to cool to room temperature, and slowly add 200-300mL of the reaction solution. The core-shell toughening agent is obtained by filtration in a 5-10 wt% calcium chloride solution, washing the filter cake 2-3 times with deionized water, transferring it to an oven at 40-60℃ and drying it to constant weight.

[0031] Furthermore, the modified filler is prepared by the following steps:

[0032] C1. Place ammonium tungstate, hydroxylamine hydrochloride, thioacetamide and deionized water in a reaction vessel and stir. Add ammonia water to adjust the pH to 8-9, add polyvinylpyrrolidone, and perform hydrothermal reaction for 10-12 hours. After post-treatment, the modified filler precursor is obtained.

[0033] The reaction principle for preparing modified filler precursors is as follows:

[0034] During the reaction, under weakly alkaline conditions, the hexavalent tungsten ions in ammonium tungstate are reduced to tetravalent tungsten ions by the reducing agent hydroxylamine hydrochloride. These tetravalent tungsten ions then undergo a hydrothermal reaction with thioacetamide. During the hydrothermal process, the ordered nucleation and two-dimensional growth of the product crystals are promoted. Polyvinylpyrrolidone can be adsorbed on the crystal surface, limiting its continued accumulation in the vertical direction, thereby promoting the formation of a two-dimensional sheet-like structure and obtaining a modified filler precursor with a two-dimensional layered structure.

[0035] C2. Place the modified filler precursor, modified graphite and deionized water in a reaction vessel and stir at room temperature for 0.5-1 h. Add alkaline buffer solution and stir at room temperature for 0.5-1 h. Add dopamine hydrochloride and react at room temperature for 10-12 h. Post-process to obtain the modified filler.

[0036] The reaction principle for preparing modified fillers is as follows:

[0037] During the reaction, in a weakly alkaline solution, dopamine connects the modified filler precursor and modified graphite together through self-oxidation, decarboxylation and covalent cross-linking, ultimately obtaining a three-dimensional layered modified filler.

[0038] Further, in step C1, the ratio of ammonium tungstate, hydroxylamine hydrochloride, thioacetamide, deionized water, and polyvinylpyrrolidone is 0.5-1g:0.1-0.2g:0.3-0.5g:50-100mL:0.5-1g, the concentration of ammonia is 1mol / L, and the hydrothermal reaction includes the following steps: transferring the reaction solution to a high-pressure reactor, heating to 175-185℃, and maintaining the temperature for 10-12 hours. The post-treatment includes the following steps: after the hydrothermal reaction is completed, waiting for the reaction system to cool to room temperature, filtering, washing the filter cake 2-3 times with deionized water and ethanol, and then transferring... The mixture is transferred to an oven at 60-70℃ and dried to constant weight to obtain the modified filler precursor. In step C2, the ratio of the modified filler precursor, modified graphite, deionized water, alkaline buffer, and dopamine hydrochloride is 0.3-0.5g:0.3-0.5g:100-120mL:100-150mL:1-2g. The alkaline buffer is Tris buffer. The post-treatment includes the following steps: after the reaction is complete, the mixture is filtered, the filter cake is washed 2-3 times with deionized water, transferred to a freeze dryer at -60℃, and dried for 6-10 hours to obtain the modified filler.

[0039] Furthermore, the preparation method of the modified graphite is as follows: concentrated sulfuric acid is placed in a reaction vessel and stirred. The reaction vessel is cooled to 0-5°C, graphite and sodium nitrate are added, and the reaction is kept at this temperature for 10-15 minutes. Potassium permanganate is slowly added, and the mixture is stirred at room temperature for 20-30 minutes. Deionized water is added, the temperature is raised to 90-95°C, and the reaction is kept at this temperature for 15-30 minutes. Hydrogen peroxide solution is added, and the modified graphite is obtained after post-treatment.

[0040] The reaction principle for the preparation of modified graphite is as follows:

[0041] During the reaction, cationic oxidants such as sodium nitrate and concentrated sulfuric acid initially oxidize the graphite. Simultaneously, sulfuric acid acts as an intercalating agent, inserting hydrogen ions into the graphite interlayers, expanding the interlayer spacing to facilitate the subsequent entry of oxidants. KMnO4 forms a strong oxidizing intermediate in concentrated sulfuric acid, and Mn... 7+As a strong oxidizing agent, it attacks the carbon-carbon bonds in the graphite layers, introducing a large number of oxygen-containing functional groups. These functional groups form on the surface and edges of the graphite sheets, causing their structure to become distorted and the interlayer to become loose, preparing for subsequent water insertion and exfoliation. Water rapidly hydrates and enters the graphite interlayer, promoting sheet expansion and partial exfoliation. The increase in temperature also accelerates the complete oxidation reaction. The addition of hydrogen peroxide terminates the reaction, forming modified graphite with a two-dimensional layered structure.

[0042] Furthermore, the ratio of concentrated sulfuric acid, graphite, sodium nitrate, potassium permanganate, deionized water, and hydrogen peroxide solution is 30-50 mL: 1-2 g: 0.5-1.5 g: 8-10 g: 50-80 mL: 20-30 mL, and the hydrogen peroxide solution is a 30 wt% aqueous solution. The post-treatment includes the following steps: after the reaction is completed, the reaction system is cooled to room temperature, filtered, and the filter cake is washed 2-3 times with a 10 wt% hydrochloric acid aqueous solution. It is then transferred to a freeze dryer at -60°C and dried for 6-10 hours to obtain modified graphite.

[0043] Furthermore, the method for preparing the corrosion-resistant material for the double-sloping wave water-spraying packed tower includes the following steps:

[0044] S1. Add modified polyvinyl chloride, core-shell toughening agent, modified filler and auxiliary additives to a mixer and mix evenly to obtain a mixture;

[0045] S2. Add the mixture to a twin-screw melt extruder, melt extrude, and pelletize to obtain the corrosion-resistant material.

[0046] Furthermore, the temperatures of the eight temperature zones of the twin-screw extruder from the feed inlet to the discharge outlet are 140℃, 145℃, 155℃, 170℃, 170℃, 160℃, 155℃ and 145℃ respectively. The main engine speed of the twin-screw extruder is 120-160 rpm and the pressure is 80-120 bar.

[0047] The present invention has the following beneficial effects:

[0048] 1. This invention modifies polyvinyl chloride (PVC) by ammoniation with a mixed amine solution, introducing olefin unsaturated double bonds and silane coupling agents. The olefins are further oxidized into epoxy bonds, which form chemical bonds with the oxygen-containing functional groups on the surface of the modified filler, blocking the penetration path of corrosive liquids. Furthermore, the trimethoxysilane introduced in the side chain can form a dense silicon-oxygen bond network with the surface of other substrates used to prepare the anti-corrosion material after hydrolysis. The Si-O-Si structure has good hydrophobic properties, which can improve the hydrophobicity of the material and make the surface of the anti-corrosion material denser, preventing moisture penetration that could lead to plasticization, whitening, and structural brittleness, thereby further improving the corrosion resistance and mechanical strength of the material.

[0049] 2. This invention prepares a rubber soft core with good toughness through the free radical polymerization reaction of butyl acrylate and dicyclopentadiene acrylate. Dicyclopentadiene acrylate is used as a crosslinking agent to introduce multiple crosslinking sites. A rigid outer shell layer composed of styrene and acrylonitrile is further coated on the outside of the rubber soft core to obtain a core-shell toughening agent. When subjected to impact or load, the rubber soft core deforms and dissipates energy, effectively preventing crack propagation in the matrix material, thereby significantly improving the overall toughness of the material. This makes the anti-corrosion material less prone to brittle fracture under low temperature, high humidity, and thermal expansion and contraction conditions, and further improving its impact resistance. Moreover, the polyolefin outer shell layer of the core-shell toughening agent is similar in structure to modified polyvinyl chloride, and has good interfacial bonding force when mixed and melted, improving the mechanical strength of the material. At the same time, the core-shell toughening agent acts as a stress buffer point for the material, which can reduce cracks caused by long-term exposure to corrosive gases, water vapor, and wind pressure, further improving the anti-corrosion performance of the material.

[0050] 3. This invention involves intercalating graphite with a strong acid and breaking its π bonds with a strong oxidizing agent, introducing oxygen-containing functional groups onto its surface to obtain modified graphite with a two-dimensional layered structure. A modified filler precursor with a two-dimensional layered structure is prepared through a hydrothermal reaction. Further, under the self-polymerization effect of dopamine hydrochloride, the two two-dimensional layered compounds are prepared into a three-dimensional layered modified filler. The modified graphite possesses high specific surface area and shielding properties. The modified filler precursor forms an SWS layer structure with tungsten atoms sandwiched between two sulfur atom layers, connected by weak van der Waals forces between the layers and strong covalent bonds within the layers. This structure is stable, exhibiting good chemical inertness and antioxidant capacity. The modified filler creates a "maze effect" in the anti-corrosion material, effectively blocking the penetration of corrosive media and improving the material's anti-corrosion performance. Furthermore, the polydopamine modified on its surface is rich in hydroxyl and amino functional groups, which can form chemical bonds with modified polyvinyl chloride, improving the interfacial bonding force of the anti-corrosion material and further enhancing its mechanical strength. Detailed Implementation

[0051] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0052] The polyvinyl chloride powder used in this invention was purchased from Dongguan Zhengtao Plastics Co., Ltd., with item number DG-1000K, grade DG-1000K, brand name Tianjin, and product name polyvinyl chloride;

[0053] The polyvinylpyrrolidone used in this invention was purchased from Jinan Zhengkang Chemical Co., Ltd., and is of industrial grade, packaged in 25kg, and branded as Jinan Zhengkang.

[0054] The graphite used in this invention was purchased from Shijiazhuang Fenghua Mineral Products Co., Ltd., under the brand name Fenghua, in accordance with the national standard, with a product specification of 80 mesh and a product name of earthy graphite.

[0055] The Tris buffer used in this invention was purchased from Ise-Ku (Lianyungang, Jiangsu) Biotechnology Co., Ltd., with the product name MES-Tris buffer, pH 8-8.5, and brand name Ise-Ku.

[0056] Example 1

[0057] This embodiment provides a method for preparing modified polyvinyl chloride (PVC) as an anti-corrosion material for a double-sloping wave water-spraying packing tower, comprising the following steps:

[0058] Step I: Preparation of modified polyvinyl chloride precursor

[0059] Weigh out 60g of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, 80g of 5-hexene-1-amine, and 2000mL of N,N-dimethylacetamide, mix them thoroughly to obtain a mixed amine solution, and set aside for later use;

[0060] Weigh out 50g of polyvinyl chloride powder and 500mL of N,N-dimethylacetamide and add them to a reaction vessel. Raise the temperature of the reaction vessel to 70℃ and stir for 1 hour. Then add 300mL of mixed amine solution dropwise to the reaction vessel and continue stirring for 3 hours. After the reaction is completed, let the reaction system cool to room temperature and transfer the reaction solution to a rotary evaporator at 80℃. Distill under reduced pressure until no liquid is collected to obtain the modified polyvinyl chloride precursor.

[0061] Step II: Preparation of modified polyvinyl chloride

[0062] Weigh 80g of polyvinyl chloride precursor and 1000mL of 1,2-dichloroethane and place them in a reaction vessel and stir. Cool to 0℃, add 5g of m-chloroperoxybenzoic acid, and keep the reaction at this temperature for 6h. After the reaction is complete, add 200mL of saturated sodium bisulfite aqueous solution to the reaction solution to terminate the reaction. After the reaction system cools to room temperature, add saturated sodium bicarbonate aqueous solution to adjust the pH to neutral. Let it stand and separate into layers. Transfer the organic phase to a rotary evaporator at 80℃ and evaporate until no liquid is collected to obtain modified polyvinyl chloride.

[0063] Example 2

[0064] This embodiment provides a method for preparing modified polyvinyl chloride (PVC) as an anti-corrosion material for a double-sloping wave water-spraying packing tower, comprising the following steps:

[0065] Step I: Preparation of modified polyvinyl chloride precursor

[0066] Weigh out 70g of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, 90g of 5-hexene-1-amine, and 2000mL of N,N-dimethylacetamide, mix them thoroughly to obtain a mixed amine solution, and set aside for later use.

[0067] Weigh out 65g of polyvinyl chloride powder and 700mL of N,N-dimethylacetamide and add them to a reaction vessel. Raise the temperature of the reaction vessel to 75℃ and stir for 1.5h. Then add 320mL of mixed amine solution dropwise to the reaction vessel and continue stirring for another 3.5h. After the reaction is complete, let the reaction system cool to room temperature and transfer the reaction solution to a rotary evaporator at 90℃. Distill under reduced pressure until no liquid is collected to obtain the modified polyvinyl chloride precursor.

[0068] Step II: Preparation of modified polyvinyl chloride

[0069] Weigh 90g of polyvinyl chloride precursor and 1250mL of 1,2-dichloroethane and place them in a reaction vessel and stir. Cool to 2℃, add 7g of m-chloroperoxybenzoic acid, and keep the reaction at this temperature for 7h. After the reaction is complete, add 250mL of saturated sodium bisulfite aqueous solution to the reaction solution to terminate the reaction. After the reaction system cools to room temperature, add saturated sodium bicarbonate aqueous solution to adjust the pH to neutral. Let it stand and separate into layers. Transfer the organic phase to a rotary evaporator at 85℃ and evaporate until no liquid is collected to obtain modified polyvinyl chloride.

[0070] Example 3

[0071] This embodiment provides a method for preparing modified polyvinyl chloride (PVC) as an anti-corrosion material for a double-sloping wave water-spraying packing tower, comprising the following steps:

[0072] Step I: Preparation of modified polyvinyl chloride precursor

[0073] Weigh out 80g of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, 100g of 5-hexene-1-amine, and 2000mL of N,N-dimethylacetamide, mix them thoroughly to obtain a mixed amine solution, and set aside for later use.

[0074] Weigh out 80g of polyvinyl chloride powder and 1000mL of N,N-dimethylacetamide and add them to a reaction vessel. Raise the temperature of the reaction vessel to 80℃ and stir for 2 hours. Then, add 350mL of mixed amine solution dropwise to the reaction vessel and continue stirring for 4 hours. After the reaction is completed, let the reaction system cool to room temperature and transfer the reaction solution to a rotary evaporator at 100℃. Distill under reduced pressure until no liquid is collected to obtain the modified polyvinyl chloride precursor.

[0075] Step II: Preparation of modified polyvinyl chloride

[0076] Weigh 100g of polyvinyl chloride precursor and 1500mL of 1,2-dichloroethane and place them in a reaction vessel and stir. Cool to 5℃, add 10g of m-chloroperoxybenzoic acid, and keep the reaction at this temperature for 8h. After the reaction is complete, add 300mL of saturated sodium bisulfite aqueous solution to the reaction solution to terminate the reaction. After the reaction system cools to room temperature, add saturated sodium bicarbonate aqueous solution to adjust the pH to neutral. Let it stand and separate into layers. Transfer the organic phase to a rotary evaporator at 90℃ and evaporate until no liquid is collected to obtain modified polyvinyl chloride.

[0077] Example 4

[0078] This embodiment provides a method for preparing a core-shell toughening agent for corrosion-resistant materials used in double-sloping wave water-spraying packed towers, comprising the following steps:

[0079] Step ①: Prepare latex seeds

[0080] Weigh out 5g of sodium dodecyl sulfate, 1500mL of deionized water and 1g of potassium carbonate and place them in a reaction vessel. Stir for 10min, add 80g of butyl acrylate and 10g of dicyclopentadiene acrylate, heat the reaction vessel to 70℃, add 20mL of 15wt% potassium persulfate aqueous solution, and keep the reaction at this temperature for 1h to obtain latex seeds.

[0081] Step 2: Preparation of core-shell toughening agent

[0082] Weigh out 100g of latex seeds, 1g of sodium dodecyl sulfate, 1000mL of deionized water, and 20mL of 15wt% potassium persulfate aqueous solution and place them in a reaction vessel. Stir for 10min, raise the temperature of the reaction vessel to 50℃, add 60g of styrene and 20g of acrylonitrile, raise the temperature of the reaction vessel to 70℃, and keep the reaction at this temperature for 1h. After the reaction is complete, wait for the reaction system to cool to room temperature, slowly add the reaction solution to 2000mL of 5wt% calcium chloride solution, filter, wash the filter cake twice with deionized water, transfer it to an oven at 40℃, and dry it to constant weight to obtain the core-shell toughening agent.

[0083] Example 5

[0084] This embodiment provides a method for preparing a core-shell toughening agent for corrosion-resistant materials used in double-sloping wave water-spraying packed towers, comprising the following steps:

[0085] Step ①: Prepare latex seeds

[0086] Weigh out 7g of sodium dodecyl sulfate, 1750mL of deionized water and 1.5g of potassium carbonate and place them in a reaction vessel. Stir for 12min, add 90g of butyl acrylate and 15g of dicyclopentadiene acrylate, heat the reaction vessel to 75℃, add 30mL of 17wt% potassium persulfate aqueous solution, and keep the reaction at this temperature for 1.5h to obtain latex seeds.

[0087] Step 2: Preparation of core-shell toughening agent

[0088] Weigh out 110g of latex seeds, 1.5g of sodium dodecyl sulfate, 1250mL of deionized water, and 30mL of 17wt% potassium persulfate aqueous solution and place them in a reaction vessel. Stir for 12min, raise the temperature of the reaction vessel to 55℃, add 70g of styrene and 30g of acrylonitrile, raise the temperature of the reaction vessel to 75℃, and keep the reaction at this temperature for 1.5h. After the reaction is complete, wait for the reaction system to cool to room temperature, slowly add the reaction solution to 2500mL of 7wt% calcium chloride solution, filter, wash the filter cake three times with deionized water, transfer it to an oven at 50℃, and dry it to constant weight to obtain the core-shell toughening agent.

[0089] Example 6

[0090] This embodiment provides a method for preparing a core-shell toughening agent for corrosion-resistant materials used in double-sloping wave water-spraying packed towers, comprising the following steps:

[0091] Step ①: Prepare latex seeds

[0092] Weigh out 10g of sodium dodecyl sulfate, 2000mL of deionized water and 2g of potassium carbonate and place them in a reaction vessel. Stir for 15min, add 100g of butyl acrylate and 20g of dicyclopentadiene acrylate, heat the reaction vessel to 80℃, add 40mL of 20wt% potassium persulfate aqueous solution, and keep the reaction at this temperature for 2h to obtain latex seeds.

[0093] Step 2: Preparation of core-shell toughening agent

[0094] Weigh out 120g of latex seeds, 2g of sodium dodecyl sulfate, 1500mL of deionized water, and 40mL of 20wt% potassium persulfate aqueous solution and place them in a reaction vessel. Stir for 15min, raise the temperature of the reaction vessel to 60℃, add 80g of styrene and 40g of acrylonitrile, raise the temperature of the reaction vessel to 80℃, and keep the reaction at this temperature for 2h. After the reaction is complete, wait for the reaction system to cool to room temperature, slowly add the reaction solution to 3000mL of 10wt% calcium chloride solution, filter, wash the filter cake three times with deionized water, transfer it to an oven at 60℃, and dry it to constant weight to obtain the core-shell toughening agent.

[0095] Example 7

[0096] This embodiment provides a method for preparing modified packing material for corrosion-resistant materials in a double-sloping wave water-spreading packed tower, including the following steps:

[0097] Step 1: Preparation of modified graphite

[0098] Weigh 300 mL of concentrated sulfuric acid and place it in a reaction vessel. Stir the vessel and cool it to 0°C. Add 10 g of graphite and 5 g of sodium nitrate. Keep the reaction vessel warm for 10 min. Slowly add 80 g of potassium permanganate and stir at room temperature for 20 min. Add 500 mL of deionized water and heat the vessel to 90°C. Keep the reaction vessel warm for 15 min. Add 200 mL of 30 wt% hydrogen peroxide aqueous solution. After the reaction is complete, wait for the reaction system to cool to room temperature, filter the mixture, wash the filter cake twice with 10 wt% hydrochloric acid aqueous solution, and transfer it to a freeze dryer at -60°C. Dry the filter cake for 6 h to obtain modified graphite.

[0099] Step 2: Preparation of modified filler precursor

[0100] Weigh out 5g of ammonium tungstate, 1g of hydroxylamine hydrochloride, 3g of thioacetamide, and 500mL of deionized water and place them in a reaction vessel. Stir the mixture and add ammonia to adjust the pH to 8. Add 5g of polyvinylpyrrolidone and transfer the reaction solution to a high-pressure vessel. Heat the mixture to 175℃ and maintain the temperature for 10 hours. After the hydrothermal reaction is complete, wait for the reaction system to cool to room temperature, filter the mixture, wash the filter cake twice with deionized water and ethanol, transfer it to an oven at 60℃, and dry it to constant weight to obtain the modified filler precursor.

[0101] Step 3: Preparation of modified filler

[0102] Weigh 3g of modified filler precursor, 3g of modified graphite and 1000mL of deionized water and place them in a reaction vessel. Stir at room temperature for 0.5h. Add 1000mL of Tris buffer and stir at room temperature for 0.5h. Add 10g of dopamine hydrochloride and react at room temperature for 10h. After the reaction is complete, filter the mixture. Wash the filter cake twice with deionized water and transfer it to a freeze dryer at -60℃. Dry for 6h to obtain the modified filler.

[0103] Example 8

[0104] This embodiment provides a method for preparing modified packing material for corrosion-resistant materials in a double-sloping wave water-spreading packed tower, including the following steps:

[0105] Step 1: Preparation of modified graphite

[0106] Weigh 400 mL of concentrated sulfuric acid and place it in a reaction vessel. Stir the vessel and cool it to 2°C. Add 15 g of graphite and 12 g of sodium nitrate. Keep the reaction vessel warm for 12 min. Slowly add 90 g of potassium permanganate and stir at room temperature for 25 min. Add 600 mL of deionized water and heat the vessel to 92°C. Keep the reaction vessel warm for 20 min. Add 250 mL of 30 wt% hydrogen peroxide aqueous solution. After the reaction is complete, wait for the reaction system to cool to room temperature, filter the mixture, wash the filter cake twice with 10 wt% hydrochloric acid aqueous solution, and transfer it to a freeze dryer at -60°C. Dry the filter cake for 8 h to obtain modified graphite.

[0107] Step 2: Preparation of modified filler precursor

[0108] Weigh out 7g of ammonium tungstate, 1.5g of hydroxylamine hydrochloride, 4g of thioacetamide, and 700mL of deionized water and place them in a reaction vessel. Stir the mixture and add ammonia to adjust the pH to 8.5. Add 7g of polyvinylpyrrolidone and transfer the reaction solution to a high-pressure vessel. Heat the mixture to 180℃ and maintain the temperature for 11 hours. After the hydrothermal reaction is complete, wait for the reaction system to cool to room temperature, filter the mixture, wash the filter cake three times with deionized water and ethanol, transfer it to an oven at 65℃, and dry it to constant weight to obtain the modified filler precursor.

[0109] Step 3: Preparation of modified filler

[0110] Weigh 4g of modified filler precursor, 4g of modified graphite and 1100mL of deionized water and place them in a reaction vessel. Stir at room temperature for 1h, add 1200mL of Tris buffer, stir at room temperature for 1h, add 15g of dopamine hydrochloride, and react at room temperature for 11h. After the reaction is complete, filter, wash the filter cake twice with deionized water, transfer it to a freeze dryer at -60℃ and dry for 8h to obtain the modified filler.

[0111] Example 9

[0112] This embodiment provides a method for preparing modified packing material for corrosion-resistant materials in a double-sloping wave water-spreading packed tower, including the following steps:

[0113] Step 1: Preparation of modified graphite

[0114] Weigh 500 mL of concentrated sulfuric acid and place it in a reaction vessel. Stir the vessel and cool it to 5°C. Add 20 g of graphite and 15 g of sodium nitrate. Keep the reaction vessel warm for 15 min. Slowly add 100 g of potassium permanganate and stir at room temperature for 30 min. Add 800 mL of deionized water and heat the vessel to 95°C. Keep the reaction vessel warm for 30 min. Add 300 mL of 30 wt% hydrogen peroxide aqueous solution. After the reaction is complete, wait for the reaction system to cool to room temperature, filter the mixture, wash the filter cake three times with 10 wt% hydrochloric acid aqueous solution, and transfer it to a freeze dryer at -60°C. Dry the cake for 10 h to obtain modified graphite.

[0115] Step 2: Preparation of modified filler precursor

[0116] Weigh out 10g of ammonium tungstate, 2g of hydroxylamine hydrochloride, 5g of thioacetamide, and 1000mL of deionized water and place them in a reaction vessel. Stir the mixture and add ammonia to adjust the pH to 9. Add 10g of polyvinylpyrrolidone and transfer the reaction solution to a high-pressure vessel. Heat the mixture to 185℃ and maintain the temperature for 12 hours. After the hydrothermal reaction is complete, wait for the reaction system to cool to room temperature, filter the mixture, wash the filter cake three times with deionized water and ethanol, transfer it to an oven at 70℃, and dry it to constant weight to obtain the modified filler precursor.

[0117] Step 3: Preparation of modified filler

[0118] Weigh 5g of modified filler precursor, 5g of modified graphite and 1200mL of deionized water and place them in a reaction vessel. Stir at room temperature for 1h, add 1500mL of Tris buffer, stir at room temperature for 1h, add 20g of dopamine hydrochloride, and react at room temperature for 12h. After the reaction is complete, filter, wash the filter cake 3 times with deionized water, transfer it to a freeze dryer at -60℃ and dry for 10h to obtain the modified filler.

[0119] Example 10

[0120] This embodiment provides a method for preparing an anti-corrosion material for a double-sloping wave water-spreading packing tower, including the following steps:

[0121] Step (a) Preparation of mixture

[0122] Trioctyl phosphate, N,N'-diphenyl-p-phenylenediamine and fatty acid amide were mixed evenly at a mass ratio of 1:0.5:2 to obtain an auxiliary additive for later use.

[0123] Weigh out the following components by weight: 60 parts modified polyvinyl chloride, 10 parts core-shell toughening agent, 5 parts modified filler and 10 parts auxiliary additives, add them to the mixer and mix evenly to obtain the mixture.

[0124] Step (b): Preparation of corrosion-resistant materials

[0125] The mixture is added to a twin-screw melt extruder, melt-extruded, and pelletized to obtain the corrosion-resistant material;

[0126] The twin-screw extruder has eight temperature zones from the feed inlet to the discharge outlet, with temperatures of 140℃, 145℃, 155℃, 170℃, 170℃, 160℃, 155℃ and 145℃ respectively. The main motor speed of the twin-screw extruder is 120 rpm and the pressure is 80 bar.

[0127] Example 11

[0128] This embodiment provides a method for preparing an anti-corrosion material for a double-sloping wave water-spreading packing tower, including the following steps:

[0129] Step (a) Preparation of mixture

[0130] Trioctyl phosphate, N,N'-diphenyl-p-phenylenediamine and fatty acid amide were mixed evenly at a mass ratio of 1:0.5:2 to obtain an auxiliary additive for later use.

[0131] Weigh out the following by weight: 70 parts modified polyvinyl chloride, 12 parts core-shell toughening agent, 6.5 parts modified filler and 11 parts auxiliary additives, add them to the mixer, mix evenly to obtain the mixture;

[0132] Step (b): Preparation of corrosion-resistant materials

[0133] The mixture is added to a twin-screw melt extruder, melt-extruded, and pelletized to obtain the corrosion-resistant material;

[0134] The twin-screw extruder has eight temperature zones from the feed inlet to the discharge outlet, with temperatures of 140℃, 145℃, 155℃, 170℃, 170℃, 160℃, 155℃ and 145℃ respectively. The main motor speed of the twin-screw extruder is 140 rpm and the pressure is 100 bar.

[0135] Example 12

[0136] This embodiment provides a method for preparing an anti-corrosion material for a double-sloping wave water-spreading packing tower, including the following steps:

[0137] Step (a) Preparation of mixture

[0138] Trioctyl phosphate, N,N'-diphenyl-p-phenylenediamine and fatty acid amide were mixed evenly at a mass ratio of 1:0.5:2 to obtain an auxiliary additive for later use.

[0139] Weigh out the following by weight: 80 parts modified polyvinyl chloride, 15 parts core-shell toughening agent, 8 parts modified filler and 12 parts auxiliary additives, add them to the mixer and mix evenly to obtain the mixture.

[0140] Step (b): Preparation of corrosion-resistant materials

[0141] The mixture is added to a twin-screw melt extruder, melt-extruded, and pelletized to obtain the corrosion-resistant material;

[0142] The twin-screw extruder has eight temperature zones from the feed inlet to the discharge outlet, with temperatures of 140℃, 145℃, 155℃, 170℃, 170℃, 160℃, 155℃ and 145℃ respectively. The main motor speed of the twin-screw extruder is 160 rpm and the pressure is 120 bar.

[0143] Comparative Example 1

[0144] The difference between this comparative example and Example 12 is that, in step (a) when preparing the mixture, polyvinyl chloride is used in an equal amount to replace the modified polyvinyl chloride.

[0145] Comparative Example 2

[0146] The difference between this comparative example and Example 12 is that the core-shell toughening agent was omitted when preparing the mixture in step (a).

[0147] Comparative Example 3

[0148] The difference between this comparative example and Example 12 is that the modified filler was omitted in step (a) when preparing the mixture.

[0149] Performance testing:

[0150] The impact strength of the cantilever beams of the corrosion-resistant materials prepared in Examples 10-12 and Comparative Examples 1-3 was tested in accordance with the standard GB / T 1843-2008 "Determination of Impact Strength of Plastic Cantilever Beams".

[0151] The tensile strength and elongation at break of the corrosion-resistant materials prepared in Examples 10-12 and Comparative Examples 1-3 were tested in accordance with the standard GB / T 528-2009 "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber".

[0152] The anticorrosion materials prepared in Examples 10-12 and Comparative Examples 1-3 were immersed in a mixed acid solution according to the standard GB / T 11547-2008 "Determination of the resistance of plastics to liquid chemical reagents". The mixed acid solution consisted of 5 wt% H2SO4 and 0.5 wt% NaHSO3 in a volume ratio of 1:1. After immersion, the cantilever beam impact strength retention rate of the anticorrosion materials was determined and calculated according to the standard GB / T 1843-2008, and the tensile strength retention rate of the anticorrosion materials was determined and calculated according to the standard GB / T 528-2009. The specific data are shown in Table 1.

[0153] Table 1. Performance test data for each sample

[0154]

[0155] Data Analysis:

[0156] Comparative analysis of the data in Table 1 reveals that the cantilever beam impact strength of the corrosion-resistant material prepared in this invention is 17.3 kJ·m. -2 The cantilever beam retains 98.6% of its impact strength, 58.1 MPa of its tensile strength, and 98.8% of its tensile strength while maintaining an elongation at break of 75.3%.

[0157] By comparing the tabular data of Example 12 and Comparative Example 1, it was found that the cantilever beam impact strength, cantilever beam impact strength retention rate, tensile strength, tensile strength retention rate, and elongation at break of the anti-corrosion material prepared in Comparative Example 1 all decreased significantly. This indicates that the present invention modifies polyvinyl chloride by ammoniation with mixed amine liquid, introduces olefin unsaturated double bonds and silane coupling agents, further oxidizes olefins into epoxy bonds, and forms chemical bonds with oxygen-containing functional groups on the surface of the modified filler, blocking the penetration path of corrosive liquids. Moreover, after the trimethoxysilane introduced in the side chain is hydrolyzed, it can form a dense silicon-oxygen bond network with the surface of other substrates used to prepare the anti-corrosion material. The Si-O-Si structure has good hydrophobic properties, which can improve the hydrophobic properties of the material, make the surface of the anti-corrosion material more dense, avoid moisture penetration leading to plasticization, whitening and structural brittleness, and further improve the corrosion resistance and mechanical strength of the material.

[0158] Comparing the tabular data of Example 12 and Comparative Example 2, it was found that the cantilever beam impact strength, cantilever beam impact strength retention rate, tensile strength, tensile strength retention rate, and elongation at break of the corrosion-resistant material prepared in Comparative Example 2 all decreased significantly. This indicates that the present invention prepares a rubber soft core with good toughness through the free radical polymerization reaction of butyl acrylate and dicyclopentadiene acrylate. Dicyclopentadiene acrylate acts as a crosslinking agent, introducing multiple crosslinking sites. Furthermore, a rigid outer shell layer composed of styrene and acrylonitrile is coated on the outside of the rubber soft core to obtain a core-shell toughening agent. The rubber soft core will deform under impact or load. The core-shell toughening agent generates deformation and dissipates energy, effectively preventing crack propagation in the matrix material, thereby significantly improving the overall toughness of the material. This makes the anti-corrosion material less prone to brittle fracture under low temperature, high humidity, and thermal expansion and contraction conditions, further improving its impact resistance. Moreover, the polyolefin outer shell of the core-shell toughening agent is similar in structure to that of modified polyvinyl chloride, exhibiting good interfacial bonding during mixing and melting, thus improving the mechanical strength of the material. At the same time, the core-shell toughening agent acts as a stress buffer point for the material, reducing cracks caused by long-term exposure to corrosive gases, water vapor, and wind pressure, further enhancing the material's corrosion resistance.

[0159] By comparing the tabular data of Example 12 and Comparative Example 3, it was found that the cantilever beam impact strength, cantilever beam impact strength retention rate, tensile strength, tensile strength retention rate, and elongation at break of the anti-corrosion material prepared in Comparative Example 3 all decreased significantly. This indicates that the present invention introduces oxygen-containing functional groups into the surface of graphite by intercalating graphite with a strong acid and breaking its π bonds with a strong oxidant, thereby obtaining modified graphite with a two-dimensional layered structure. A modified filler precursor with a two-dimensional layered structure is prepared by hydrothermal reaction. Furthermore, under the self-polymerization of dopamine hydrochloride, the two compounds with two-dimensional layered structures are prepared into a three-dimensional layered structure. Modified fillers, among which modified graphite possesses high specific surface area and shielding properties. The precursor of the modified filler consists of tungsten atoms sandwiched between two sulfur atom layers to form an SWS layer structure. The interlayers are connected by weak van der Waals forces, while the intralayers are connected by strong covalent bonds, resulting in a stable structure with good chemical inertness and antioxidant capacity. This allows the modified filler to form a "maze effect" in anti-corrosion materials, effectively blocking the penetration of corrosive media and improving the material's anti-corrosion performance. Furthermore, the polydopamine modified on its surface is rich in functional groups such as hydroxyl and amino groups, which can form chemical bonds with modified polyvinyl chloride, improving the interfacial bonding force of the anti-corrosion material and further enhancing its mechanical strength.

[0160] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A corrosion-resistant material for a double-sloping wave water-spreading packing tower, characterized in that, It includes the following components by weight: 60-80 parts modified polyvinyl chloride, 10-15 parts core-shell toughening agent, 5-8 parts modified filler and 10-12 parts auxiliary additives; The auxiliary additives consist of dispersant, antioxidant and lubricant in a mass ratio of 1:0.5:

2.

2. The anti-corrosion material for a double-sloping wave water-spreading packing tower according to claim 1, characterized in that, The modified polyvinyl chloride is prepared by the following steps: A1. Add polyvinyl chloride powder and N,N-dimethylacetamide to a reaction vessel. Raise the temperature of the reaction vessel to 70-80℃ and keep it warm and stir for 1-2 hours. Then, add mixed amine solution dropwise to the reaction vessel and continue to keep it warm and stir for 3-4 hours. The modified polyvinyl chloride precursor is obtained by post-treatment. A2. Place the polyvinyl chloride precursor and 1,2-dichloroethane in a reaction vessel and stir. Cool the mixture to 0-5℃, add m-chloroperoxybenzoic acid, and keep it at the temperature for 6-8 hours. After post-treatment, the modified polyvinyl chloride is obtained.

3. The anti-corrosion material for a double-sloping wave water-spreading packing tower according to claim 2, characterized in that, In step A1, the ratio of polyvinyl chloride powder, N,N-dimethylacetamide, and mixed amine solution is 5-8g:50-100mL:30-35mL. The mixed amine solution is obtained by mixing N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, 5-hexen-1-amine, and N,N-dimethylacetamide in a ratio of 6-8g:8-10g:200mL. In step A2, the ratio of polyvinyl chloride precursor, 1,2-dichloroethane, and m-chloroperoxybenzoic acid is 8-10g:100-150mL:0.5-1g.

4. The anti-corrosion material for a double-sloping wave water-spreading packing tower according to claim 1, characterized in that, The core-shell toughening agent is prepared by the following steps: B1. Place sodium dodecyl sulfate, deionized water and potassium carbonate in a reaction vessel and stir for 10-15 min. Add butyl acrylate and dicyclopentadiene acrylate. Heat the reaction vessel to 70-80℃ and add potassium persulfate solution. Keep the reaction at this temperature for 1-2 h to obtain latex seeds. B2. Place latex seeds, sodium dodecyl sulfate, deionized water, and potassium persulfate solution in a reaction vessel and stir for 10-15 minutes. Heat the reaction vessel to 50-60°C, add styrene and acrylonitrile, and heat the reaction vessel to 70-80°C. Keep the reaction at this temperature for 1-2 hours. Post-treatment yields the core-shell toughening agent.

5. The anti-corrosion material for a double-sloping wave water-spreading packing tower according to claim 4, characterized in that, In step B1, the ratio of sodium dodecyl sulfate, deionized water, potassium carbonate, butyl acrylate, dicyclopentadiene acrylate, and potassium persulfate solution is 0.5-1g:150-200mL:0.1-0.2g:8-10g:1-2g:2-4mL, and the potassium persulfate solution is a 15-20wt% aqueous solution. In step B2, the ratio of latex seeds, sodium dodecyl sulfate, deionized water, potassium persulfate solution, styrene, and acrylonitrile is 10-12g:0.1-0.2g:100-150mL:2-4mL:6-8g:2-4g, and the potassium persulfate solution is a 15-20wt% aqueous solution.

6. The anti-corrosion material for a double-sloping wave water-spreading packing tower according to claim 1, characterized in that, The modified filler is prepared by the following steps: C1. Place ammonium tungstate, hydroxylamine hydrochloride, thioacetamide and deionized water in a reaction vessel and stir. Add ammonia water to adjust the pH to 8-9, add polyvinylpyrrolidone, and perform hydrothermal reaction for 10-12 hours. After post-treatment, the modified filler precursor is obtained. C2. Place the modified filler precursor, modified graphite and deionized water in a reaction vessel and stir at room temperature for 0.5-1 h. Add alkaline buffer solution and stir at room temperature for 0.5-1 h. Add dopamine hydrochloride and react at room temperature for 10-12 h. Post-process to obtain the modified filler.

7. The anti-corrosion material for a double-sloping wave water-spreading packing tower according to claim 6, characterized in that, In step C1, the ratio of ammonium tungstate, hydroxylamine hydrochloride, thioacetamide, deionized water, and polyvinylpyrrolidone is 0.5-1g:0.1-0.2g:0.3-0.5g:50-100mL:0.5-1g, and the concentration of ammonia is 1mol / L. In step C2, the ratio of modified filler precursor, modified graphite, deionized water, alkaline buffer, and dopamine hydrochloride is 0.3-0.5g:0.3-0.5g:100-120mL:100-150mL:1-2g, and the alkaline buffer is Tris buffer.

8. The anti-corrosion material for a double-sloping wave water-spreading packing tower according to claim 6, characterized in that, The modified graphite is prepared by: placing concentrated sulfuric acid in a reaction vessel and stirring, cooling the reaction vessel to 0-5℃, adding graphite and sodium nitrate, keeping the reaction at this temperature for 10-15 min, slowly adding potassium permanganate, stirring at room temperature for 20-30 min, adding deionized water, raising the temperature to 90-95℃, keeping the reaction at this temperature for 15-30 min, adding hydrogen peroxide solution, and then post-processing to obtain modified graphite.

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