Halogen corrosion resistant composite material and preparation method thereof

Abstract

The invention belongs to the technical field of composite materials, and particularly relates to a halogen corrosion resistant composite material and a preparation method thereof. The halogen-corrosion-resistant composite material is prepared from the following components in parts by weight: 60 to 70 parts of nylon 56, 10 to 20 parts of semi-aromatic nylon, 25 to 35 parts of modified carbon fiber, 5 to 10 parts of graphene oxide and 1 to 3 parts of pentaerythritol polyol, the modified carbon fibers are carbon fibers modified by adopting an acidic solution. Oxygen-containing functional groups on the surface of the modified carbon fiber, oxidation energy-containing groups on the surface of the graphene oxide, a polyhydroxy structure on pentaerythritol and amido on nylon 56 can form relatively strong chemical bonds or hydrogen bonds, so that the filler is closely linked together. The combination of the carbon fiber with the linear structure and the graphene oxide with the lamellar structure is more beneficial to improving the barrier effect and improving the halogen corrosion resistance of the composite material.

Description

Technical Field

[0001] The present invention belongs to the technical field of composite materials, and particularly relates to a halogen-resistant corrosion composite material and a preparation method thereof. Background Art

[0002] In the process of chemical production, especially in the production of halogen-containing compounds such as trichlorotrifluoroethane, the main media for corroding equipment such as condensers, evaporators, and distillation columns are halides and their salts in organic substances. Especially halogen-containing acids (such as hydrochloric acid, hydrofluoric acid, etc.), due to their corrosive effects, some equipment often corrodes and perforates after only a few months of use, causing great losses to production. Therefore, in the chemical production of halogen-containing compounds such as trichlorotrifluoroethane, it is necessary to conduct research on anti-corrosion material selection. The chemical composition and mineral composition of materials have an important impact on their corrosion resistance. If the composition of the material is prone to react with acids, alkalis, salts, oxygen, or certain chemical substances, or the composition of the material is easily soluble in water or certain solvents, then its corrosion resistance is poor.

[0003] Some metal materials resistant to halides and their salts, such as Hastelloy B, with an alloy content of over 70%, not only have a high material cost but also significantly deteriorate processing performance. Titanium alloys have excellent corrosion resistance, especially in strong acid and strong alkali environments, but also face the problem of high cost. Therefore, it is necessary to screen out corrosion-resistant and low-cost materials to meet the requirements of equipment used in chemical production. First is material selection. According to the characteristics of the media contacted in chemical production, select appropriate corrosion-resistant materials. Second is structural design. Avoid dead corners and gaps because these places are prone to accumulate corrosive media and cause local corrosion. Reasonably design the wall thickness of the equipment, which should not only meet the strength requirements but also consider the corrosion allowance to ensure that the equipment will not fail due to corrosion during its service life. Also, consider the maintainability of the equipment for easy daily inspection, cleaning, and repair. At the same time, necessary corrosion protection designs should be carried out, such as using coating, lining, and other protection measures.

[0004] Nylon polymers have good corrosion resistance and excellent processing properties, which can meet the performance requirements of corrosion resistance and easy processing in chemical production. Nylon is a type of polymer containing repeating amide bonds. Nylon has a wide range of applications in the fields of engineering plastics and fiber materials due to its good heat resistance, chemical corrosion resistance, wear resistance, and excellent mechanical properties. For example, the manufacturing of engineering plastic products, such as mechanical parts, automotive components, electrical equipment housings, and some special-purpose aerospace products, can also be made into common nylon fiber materials due to its mechanical and heat resistance properties. Some bio-based nylons can be used to manufacture medical devices, medical materials, and packaging materials due to their biocompatibility and chemical resistance. Nylon is a key and important polymer material with a wide range of applications and plays a crucial role in fields such as engineering construction, spinning, chemical equipment, and packaging.

[0005] According to the different molecular structures of nylon, it can be divided into three categories: aliphatic, semi-aromatic, and fully aromatic. Aliphatic nylon was the first to be industrially produced. Its main chain contains no other groups except methylene and amide groups, and this type of nylon has good processability. With the increase of aromatic ring structures in the main chain, the thermodynamic properties, rigidity, and mechanical strength of the material also increase, and it also has characteristics such as corrosion resistance. Fully aromatic nylon also has some disadvantages, such as high melting point and insolubility in organic solvents, which make its processing performance poor, increase the processing cost, and limit its application fields. Among them, bio-based aliphatic nylon has good processing performance and low cost, and is the most promising material. The Chinese invention patent application with the publication number CN119307093A provides a highly alcoholysis-resistant glass fiber-reinforced nylon material. By adding a small amount of mica to the matrix raw material, the insulation and heat resistance of the prepared glass fiber-reinforced nylon material are improved to a certain extent, the range of products that can be made from the material is expanded, and the stability of the products is improved, which helps the products resist the corrosion of strong acids and strong alkalis. However, the poor salt corrosion resistance of bio-based aliphatic nylon limits its further application. Summary of the Invention

[0006] The object of the present invention is to provide a halogen-resistant corrosion composite material and its preparation method. The halogen-resistant corrosion composite material has excellent corrosion resistance and expands its application in the production process of halogen-containing compounds such as trichlorotrifluoroethane.

[0007] To achieve the above object, in the first aspect of the present invention, a halogen-resistant corrosion composite material is provided, which comprises the following components in parts by weight: 60 - 70 parts of nylon 56, 10 - 20 parts of semi-aromatic nylon, 25 - 35 parts of modified carbon fiber, 5 - 10 parts of graphene oxide, 1 - 3 parts of pentaerythritol-based polyol; the modified carbon fiber is carbon fiber modified with an acidic solution.

[0008] Nylon 56 is a new type of bio-based polyamide, and its monomer bio-based 1,5-pentanediamine is derived from glucose. Glucose is fermented biologically to produce lysine, and lysine is decarboxylated at both ends under the action of lysine decarboxylase to obtain bio-based 1,5-pentanediamine. Subsequently, the bio-based 1,5-pentanediamine with an odd number of carbon atoms and the petroleum-based adipic acid with an even number of carbon atoms are subjected to melt polycondensation to prepare bio-based nylon 56. Bio-based nylon 56 has better melt flow properties than PA66, which is more conducive to being applied in the field of complex workpieces such as engineering equipment. However, compared with other types of aliphatic nylon, due to the odd-even effect, bio-based nylon 56 has poor halogen corrosion resistance and low mechanical strength. In order to improve its corrosion resistance, a certain amount of semi-aromatic nylon is added in the present invention. Due to the presence of the benzene ring, semi-aromatic nylon can not only improve the mechanical strength of the composite material, but also has good barrier properties, weakening the odd-even effect of nylon 56 and preventing the intrusion of corrosive substances, thereby improving the corrosion resistance of the composite material.

[0009] However, as an aliphatic nylon, nylon 56 still has lower mechanical properties compared with aromatic nylon. In order to further improve its mechanical strength on the basis of meeting its halogen corrosion resistance, a certain amount of modified carbon fiber, graphene oxide and pentaerythritol are added in the present invention.

[0010] Carbon fiber is a fiber material with a carbon content of over 90%. It is usually a high-performance fiber material with a turbostratic graphite structure obtained from organic polymer precursors such as polyacrylonitrile, pitch, phenolic, and viscose through steps such as spinning, pre-oxidation, carbonization, and graphitization. Carbon fiber has excellent properties such as high specific strength, high specific modulus, high temperature resistance, wear resistance, corrosion resistance, and high thermal conductivity, and is widely used as a reinforcement for high-performance composite materials. Although carbon fiber-reinforced nylon 56-based composites have great advantages, there are still some problems in their preparation and application processes that restrict the development of nylon 56 resin-based composites. Nylon 56 resin usually has a high viscosity, and carbon fiber has high surface inertness. Therefore, it is easy to have problems with difficult two-phase impregnation during the preparation of composites, which makes it difficult to simultaneously achieve the preparation of composites and the improvement of interfacial strength. At the same time, the high viscosity of nylon 56 makes it difficult for carbon fiber to be evenly distributed in the matrix material, resulting in a low density of the composite material and making it difficult to improve the halogen corrosion resistance. For this reason, the present invention uses a corrosive acidic solution to treat the surface of carbon fiber. This treatment has two functions. First, after oxidation treatment, the surface of carbon fiber usually has structural forms such as grooves or pits. When the carbon fiber is embedded in the matrix, the rough surface structure of the carbon fiber can mechanically interlock the fiber and the matrix together, thereby enhancing the two-phase interface bonding. Second, the oxidation treatment can generate a large number of oxygen-containing groups on the surface of carbon fiber, improve the surface inertness of carbon fiber, and enhance the wettability and bonding strength between carbon fiber and the resin matrix. More importantly, the oxygen-containing functional groups on the surface of carbon fiber can form strong chemical bonds or hydrogen bonds with the oxygen-containing functional groups on the surface of graphene oxide, the polyhydroxy structure on pentaerythritol, and the amide group on nylon 56, making the fillers closely connected together. The linear structure of carbon fiber combined with the lamellar structure of graphene oxide is more conducive to improving the barrier effect and enhancing the halogen corrosion resistance of the composite material. Pentaerythritol can not only serve as a link for modifying carbon fiber and graphene oxide connection, but also improve the processing performance of the composite material, promote the dispersion of inorganic fillers, increase the density of the composite material, and overcome the negative defects such as porosity and looseness caused by the surface grooves of modified carbon fiber.

[0011] Specifically, the semi-aromatic nylon is one or more of nylon 6T, nylon 6I, nylon 6T / 66, nylon 6T / 6, and nylon 6T / 6I. The above semi-aromatic nylon takes into account the advantages of processing performance and barrier performance, not only improving the melt fluidity of nylon 56 resin to meet the preparation requirements of complex workpieces, but also enhancing the corrosion resistance of the composite material.

[0012] Specifically, the specific preparation process of the modified carbon fiber is: putting the cleaned carbon fiber into a concentrated nitric acid solution, performing ultrasonic modification treatment, and taking it out and washing it to neutrality to obtain the modified carbon fiber.

[0013] Specifically, the cleaning is carried out using a mixed solution of ethanol and acetone, and the concentration of the concentrated nitric acid solution is 60-70 wt%. Concentrated nitric acid etching not only removes impurities on the surface of carbon fibers but also introduces oxygen-containing functional groups such as carboxyl groups (COOH) and hydroxyl groups (OH) on the surface. These functional groups increase the polarity of the carbon fiber surface, making it easier to combine with the nylon 56 resin matrix, thereby improving the interfacial strength and overall performance of the composite material.

[0014] Specifically, the temperature of the ultrasonic modification treatment is 40-50 °C, and the time is 0.5-1.5 h.

[0015] Specifically, the pentaerythritol-based polyol is one or more of monopentaeitythritol, dipentaerythritol, and tripentaerythritol.

[0016] Specifically, the halogen-resistant corrosion composite material further contains additives.

[0017] Specifically, the additives are one or more of lubricants, coupling agents, antioxidants, release agents, nucleating agents, flow modifiers, and colorants.

[0018] Specifically, the lubricant is one or more of polytetrafluoroethylene, zinc stearate, calcium stearate, talcum powder, silicone oil, and polyethylene wax. The lubricant significantly improves the processing performance of the nylon 56 composite material and increases production efficiency by reducing friction, lowering torque, and reducing die buildup. In addition, the lubricant can also improve the surface gloss and smoothness of the product, reduce the friction coefficient, thereby enhancing the durability and user experience of the product.

[0019] Specifically, the coupling agent is one or more of silane coupling agents, titanate coupling agents, phosphate coupling agents, and aluminate coupling agents.

[0020] The second aspect of the present invention provides a method for preparing a halogen-resistant corrosion composite material, comprising the following steps: (1) Weigh each component by weight; (2) Pre-mix all raw materials except the modified carbon fibers evenly and feed them through the main feeding port of the twin-screw extruder, and the modified carbon fibers are added through the side feeding port; (3) Melt, extrude, and pelletize to obtain the halogen-resistant corrosion composite material.

[0021] The material is processed by a twin-screw extruder. When the material advances in the screw, the heating device outside the barrel heats the material, and at the same time, the rotation of the screw generates shear and frictional heat on the material. Under the combined action of these two heat sources, the material gradually changes from a solid state to a molten state, realizing plasticization. In particular, the screw speed of the twin-screw extruder is 400 - 500 rpm. The melt extrusion temperature is not particularly limited and can be adjusted according to the type of semi-aromatic nylon and its melting point, specifically 280 - 320 °C.

[0022] Beneficial effects: The present invention provides a halogen-resistant composite material and a preparation method thereof. The halogen-resistant composite material has excellent corrosion resistance, expanding its application in the production process of halogen-containing compounds such as trichlorotrifluoroethane. Bio-based nylon 56 also has more excellent melt flow properties than PA66, which is more conducive to its application in complex workpiece fields such as engineering equipment. The addition of modified carbon fiber, graphene oxide, and pentaerythritol further improves its mechanical strength on the basis of meeting its halogen corrosion resistance. After oxidation treatment, the surface of the carbon fiber usually has structural forms such as grooves or pits, enhancing the interfacial bonding between the two phases. The oxygen-containing functional groups on the surface of the carbon fiber can form strong chemical bonds or hydrogen bonds with the oxygen-containing functional groups on the surface of graphene oxide, the polyhydroxy structure on pentaerythritol, and the amide groups on nylon 56, making them closely linked together. The linear structure of carbon fiber combined with the lamellar structure of graphene oxide is more conducive to improving the barrier effect and enhancing the halogen corrosion resistance of the composite material. Pentaerythritol can not only serve as a link for connecting modified carbon fiber and graphene oxide, but also improve the processing performance of the composite material, promote the dispersion of inorganic fillers, increase the density of the composite material, and overcome the negative defects caused by the surface grooves of the modified carbon fiber. Specific embodiments

[0023] The following details the specific embodiments of the present disclosure. It should be understood that the specific embodiments described herein are only for the purpose of illustrating and explaining the present disclosure, and are not intended to limit the present disclosure.

[0024] In the present disclosure, the endpoints and any values of the disclosed endpoint values are not limited to the exact range or value. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0025] Example 1 A halogen-resistant composite material, comprising the following components in parts by weight: 60 parts of nylon 56, 12 parts of semi-aromatic nylon 6T / 66, 25 parts of modified carbon fiber, 5 parts of graphene oxide, 1 part of dipentaerythritol, 1 part of polytetrafluoroethylene; The specific preparation process of the modified carbon fiber is as follows: put the cleaned carbon fiber into a concentrated nitric acid solution, perform ultrasonic modification treatment, take it out and wash it to neutrality to obtain the modified carbon fiber; the cleaning is carried out with a mixed solution of ethanol and acetone, the concentration of the concentrated nitric acid solution is 65wt%; the temperature of the ultrasonic modification treatment is 40°C and the time is 1.5h.

[0026] Example 2 A halogen-resistant corrosion composite material, comprising the following components in parts by weight: 70 parts of nylon 56, 16 parts of semi-aromatic nylon 6T / 66, 35 parts of modified carbon fiber, 10 parts of graphene oxide, 3 parts of dipentaerythritol, 5 parts of talcum powder; The specific preparation process of the modified carbon fiber is as follows: put the cleaned carbon fiber into a concentrated nitric acid solution, perform ultrasonic modification treatment, take it out and wash it to neutrality to obtain the modified carbon fiber; the cleaning is carried out with a mixed solution of ethanol and acetone, the concentration of the concentrated nitric acid solution is 68wt%; the temperature of the ultrasonic modification treatment is 50°C and the time is 0.5h.

[0027] Example 3 A halogen-resistant corrosion composite material, comprising the following components in parts by weight: 60 parts of nylon 56, 16 parts of semi-aromatic nylon 6T / 66, 25 parts of modified carbon fiber, 10 parts of graphene oxide, 3 parts of dipentaerythritol, 1 part of polytetrafluoroethylene; The specific preparation process of the modified carbon fiber is as follows: put the cleaned carbon fiber into a concentrated nitric acid solution, perform ultrasonic modification treatment, take it out and wash it to neutrality to obtain the modified carbon fiber; the cleaning is carried out with a mixed solution of ethanol and acetone, the concentration of the concentrated nitric acid solution is 65wt%; the temperature of the ultrasonic modification treatment is 40°C and the time is 0.8h.

[0028] Example 4 A halogen-resistant corrosion composite material, comprising the following components in parts by weight: 66 parts of nylon 56, 10 parts of semi-aromatic nylon 6T / 66, 30 parts of modified carbon fiber, 8 parts of graphene oxide, 2 parts of dipentaerythritol, 3 parts of talcum powder; The specific preparation process of the modified carbon fiber is as follows: put the cleaned carbon fiber into a concentrated nitric acid solution, perform ultrasonic modification treatment, take it out and wash it to neutrality to obtain the modified carbon fiber; the cleaning is carried out with a mixed solution of ethanol and acetone, the concentration of the concentrated nitric acid solution is 65wt%; the temperature of the ultrasonic modification treatment is 46°C and the time is 1.1h.

[0029] Example 5 A halogen-resistant corrosion composite material, comprising the following components in parts by weight: 62 parts of nylon 56, 13 parts of semi-aromatic nylon 6T / 66, 28 parts of modified carbon fiber, 6 parts of graphene oxide, 1.5 parts of dipentaerythritol, 2.5 parts of polytetrafluoroethylene; The specific preparation process of the modified carbon fiber is as follows: put the cleaned carbon fiber into a concentrated nitric acid solution, perform ultrasonic modification treatment, take it out and wash it to neutrality to obtain the modified carbon fiber; the cleaning is carried out with a mixed solution of ethanol and acetone, the concentration of the concentrated nitric acid solution is 68wt%; the temperature of the ultrasonic modification treatment is 43°C and the time is 1.2h.

[0030] Example 6 A halogen-resistant corrosion composite material, comprising the following components in parts by weight: 68 parts of nylon 56, 15 parts of semi-aromatic nylon 6T / 66, 33 parts of modified carbon fiber, 9 parts of graphene oxide, 2.6 parts of dipentaerythritol, 4.2 parts of talcum powder; The specific preparation process of the modified carbon fiber is as follows: put the cleaned carbon fiber into a concentrated nitric acid solution, perform ultrasonic modification treatment, take it out and wash it to neutrality to obtain the modified carbon fiber; the cleaning is carried out with a mixed solution of ethanol and acetone, the concentration of the concentrated nitric acid solution is 65wt%; the temperature of the ultrasonic modification treatment is 48°C and the time is 0.8h.

[0031] Example 7 A halogen-resistant corrosion composite material, comprising the following components in parts by weight: 66 parts of nylon 56, 20 parts of semi-aromatic nylon 6T / 66, 30 parts of modified carbon fiber, 8 parts of graphene oxide, 2 parts of dipentaerythritol, 3 parts of talcum powder; The specific preparation process of the modified carbon fiber is as follows: put the cleaned carbon fiber into a concentrated nitric acid solution, perform ultrasonic modification treatment, take it out and wash it to neutrality to obtain the modified carbon fiber; the cleaning is carried out with a mixed solution of ethanol and acetone, the concentration of the concentrated nitric acid solution is 65wt%; the temperature of the ultrasonic modification treatment is 46°C and the time is 1.1h.

[0032] Example 8 A halogen-resistant corrosion composite material, comprising the following components in parts by weight: 64 parts of nylon 56, 15.5 parts of semi-aromatic nylon 6T / 66, 28 parts of modified carbon fiber, 8.5 parts of graphene oxide, 2.3 parts of dipentaerythritol, 3.5 parts of polytetrafluoroethylene; The specific preparation process of the modified carbon fiber is as follows: Put the cleaned carbon fiber into a concentrated nitric acid solution, perform ultrasonic modification treatment, take it out and wash it until neutral to obtain the modified carbon fiber; the cleaning is carried out using a mixed solution of ethanol and acetone, the concentration of the concentrated nitric acid solution is 68wt%; the temperature of the ultrasonic modification treatment is 43°C, and the time is 0.9h.

[0033] Example 9 A halogen-resistant corrosion composite material comprises the following components in parts by weight: 67.5 parts of nylon 56, 14.5 parts of semi-aromatic nylon 6T / 66, 31 parts of modified carbon fiber, 7.5 parts of graphene oxide, 2.2 parts of dipentaerythritol, 3.5 parts of talcum powder; The specific preparation process of the modified carbon fiber is as follows: Put the cleaned carbon fiber into a concentrated nitric acid solution, perform ultrasonic modification treatment, take it out and wash it until neutral to obtain the modified carbon fiber; the cleaning is carried out using a mixed solution of ethanol and acetone, the concentration of the concentrated nitric acid solution is 65wt%; the temperature of the ultrasonic modification treatment is 45°C, and the time is 0.7h.

[0034] Example 10 A halogen-resistant corrosion composite material comprises the following components in parts by weight: 66 parts of nylon 56, 14 parts of semi-aromatic nylon 6T / 66, 30 parts of modified carbon fiber, 8 parts of graphene oxide, 2 parts of dipentaerythritol, 3 parts of talcum powder; The specific preparation process of the modified carbon fiber is as follows: Put the cleaned carbon fiber into a concentrated nitric acid solution, perform ultrasonic modification treatment, take it out and wash it until neutral to obtain the modified carbon fiber; the cleaning is carried out using a mixed solution of ethanol and acetone, the concentration of the concentrated nitric acid solution is 65wt%; the temperature of the ultrasonic modification treatment is 46°C, and the time is 1.1h.

[0035] Comparative Example 1 A halogen-resistant corrosion composite material comprises the following components in parts by weight: 66 parts of nylon 56, 14 parts of semi-aromatic nylon 6T / 66, 30 parts of modified carbon fiber, 0 part of graphene oxide, 10 parts of dipentaerythritol, 3 parts of talcum powder; The specific preparation process of the modified carbon fiber is as follows: Put the cleaned carbon fiber into a concentrated nitric acid solution, perform ultrasonic modification treatment, take it out and wash it until neutral to obtain the modified carbon fiber; the cleaning is carried out using a mixed solution of ethanol and acetone, the concentration of the concentrated nitric acid solution is 65wt%; the temperature of the ultrasonic modification treatment is 46°C, and the time is 1.1h.

[0036] Comparative Example 2 A halogen-resistant corrosion composite material comprises the following components in parts by weight: 66 parts of nylon 56, 14 parts of semi-aromatic nylon 6T / 66, 30 parts of modified carbon fiber, 10 parts of graphene oxide, 0 parts of dipentaerythritol, 3 parts of talcum powder; The specific preparation process of the modified carbon fiber is as follows: put the washed carbon fiber into a concentrated nitric acid solution, perform ultrasonic modification treatment, take it out and wash it until neutral to obtain the modified carbon fiber; the washing is carried out with a mixed solution of ethanol and acetone, and the concentration of the concentrated nitric acid solution is 65wt%; the temperature of the ultrasonic modification treatment is 46°C and the time is 1.1h.

[0037] Comparative Example 3 A halogen-resistant corrosion composite material, comprising the following components in parts by weight: 66 parts of nylon 56, 14 parts of semi-aromatic nylon 6T / 66, 30 parts of washed carbon fiber, 8 parts of graphene oxide, 2 parts of dipentaerythritol, 3 parts of talcum powder; The specific preparation process of the washed carbon fiber is as follows: wash the carbon fiber with a mixed solution of ethanol and acetone.

[0038] Comparative Example 4 A halogen-resistant corrosion composite material, comprising the following components in parts by weight: 66 parts of nylon 56, 14 parts of semi-aromatic nylon 6T / 66, 30 parts of modified carbon fiber, 8 parts of graphene oxide, 5 parts of dipentaerythritol, 3 parts of talcum powder; The specific preparation process of the modified carbon fiber is as follows: put the washed carbon fiber into a concentrated nitric acid solution, perform ultrasonic modification treatment, take it out and wash it until neutral to obtain the modified carbon fiber; the washing is carried out with a mixed solution of ethanol and acetone, and the concentration of the concentrated nitric acid solution is 65wt%; the temperature of the ultrasonic modification treatment is 46°C and the time is 1.1h.

[0039] The preparation processes of the halogen-resistant corrosion composite materials in the above examples and comparative examples are the same, specifically as follows: (1) Weigh each component by weight; (2) Premix the raw materials except the modified carbon fiber (washed carbon fiber in Comparative Example 3) evenly and feed them from the main feeding port of the twin-screw extruder, and the modified carbon fiber (washed carbon fiber in Comparative Example 3) is added through the side feeding port; (3) Melt, extrude and pelletize to obtain the halogen-resistant corrosion composite material; the screw speed of the twin-screw extruder is 450 rpm; the melt extrusion temperature is 300°C.

[0040] Performance test: Deionized water was used as the solvent to prepare a 3.8 mol / L hydrochloric acid solution, and an accelerated aging test was carried out on the halogen-resistant composite material under sealed conditions at 45°C. Specifically: The halogen-resistant composite materials prepared in the above examples and comparative examples were made into standard specimens, and their initial tensile strength (MPa, ISO527), initial flexural strength (MPa, ISO178), and tensile strength and flexural strength after soaking in a 3.8 mol / L hydrochloric acid solution for 10 days under sealed conditions at 45°C were tested, and their tensile strength retention rate and flexural strength retention rate were calculated. The results are shown in Table 1 - Table 2.

[0041] Table 1 Performance of the halogen-resistant composite materials prepared in Examples 1 - 7

[0042] Table 2 Performance of the halogen-resistant composite materials prepared in Examples 8 - 10 and Comparative Examples 1 - 4

[0043] It can be seen from Table 1 and Table 2 that the addition of modified carbon fiber, graphene oxide, and pentaerythritol further improves its mechanical strength on the basis of meeting its halogen resistance. After oxidation treatment, the surface of the carbon fiber usually has structural forms such as grooves or pits, which enhances the interfacial bonding between the two phases. The oxygen-containing functional groups on the surface of the carbon fiber can form strong chemical bonds or hydrogen bonds with the oxygen-containing functional groups on the surface of graphene oxide, the polyhydroxy structure on pentaerythritol, and the amide groups on nylon 56, making them closely connected together. The linear structure of the carbon fiber combined with the lamellar structure of graphene oxide is more conducive to improving the barrier effect and the halogen resistance of the composite material. Pentaerythritol can not only serve as a link connecting modified carbon fiber and graphene oxide, but also improve the processing performance of the composite material, promote the dispersion of inorganic fillers, improve the compactness of the composite material, overcome the negative defects caused by the surface grooves of the modified carbon fiber, improve the halogen acid corrosion resistance of the composite material, and have a high mechanical strength retention rate.

[0044] Compared with Example 10, Comparative Examples 1-2 lack graphene oxide or pentaerythritol, and their halogen corrosion resistance is significantly reduced. It further illustrates that the oxygen-containing functional groups on the surface of carbon fiber can form strong chemical bonds or hydrogen bonds with the oxygen-containing functional groups on the surface of graphene oxide, the polyhydroxy structure on pentaerythritol, and the amide groups on nylon 56, improving the halogen corrosion resistance of the composite material. In Comparative Example 3, the carbon fiber was not oxidized, so neither the structural forms such as grooves or pits could be formed on the surface of the carbon fiber, nor could oxygen-containing functional groups be introduced to enhance the interaction with graphene oxide and dipentaerythritol. The composite material has a loose structure and is not conducive to blocking the erosion of corrosive substances. In Comparative Example 4, too much pentaerythritol was used. Although the initial mechanical properties were not greatly affected, as a small molecule additive, when its dosage is too much, there may be technical problems of precipitation, which is not only not conducive to the processing of the composite material, but also causes surface defects in the product and is likely to cause rapid corrosion as corrosion sites.

[0045] The above examples are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing examples, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing examples, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A halogen-resistant corrosion composite material, characterized in that, Comprising the following components in parts by weight: 60 - 70 parts of nylon 56, 10 - 20 parts of semi-aromatic nylon, 25 - 35 parts of modified carbon fiber, 5 - 10 parts of graphene oxide, 1 - 3 parts of pentaerythritol-based polyol; The modified carbon fiber is carbon fiber modified with an acidic solution.

2. The halogen-resistant corrosion composite material according to claim 1, characterized in that, The semi-aromatic nylon is one or more of nylon 6T, nylon 6I, nylon 6T / 66, nylon 6T / 6, nylon 6T / 6I.

3. A halogen-resistant composite material according to claim 1, characterized in that, The specific preparation process of the modified carbon fiber is: putting the cleaned carbon fiber into a concentrated nitric acid solution, performing ultrasonic modification treatment, taking it out and washing until neutral to obtain the modified carbon fiber.

4. The corrosion-resistant halogen composite material according to claim 3, characterized in that The cleaning is carried out with a mixed solution of ethanol and acetone, and the concentration of the concentrated nitric acid solution is 60 - 70wt%.

5. The halogen-resistant corrosion composite material according to claim 3, wherein, The temperature of the ultrasonic modification treatment is 40 - 50°C, and the time is 0.5 - 1.5h.

6. The halogen-resistant corrosion composite material according to claim 1, wherein The pentaerythritol-based polyol is one or more of monopentaeylitol, dipentaerythritol, tripentaerythritol.

7. A halogen-resistant composite material according to claim 1, characterized in that, The halogen-resistant corrosion composite material further contains additives.

8. The corrosion-resistant halogen composite material according to claim 7, wherein The additives are one or more of lubricants, coupling agents, antioxidants, mold release agents, nucleating agents, flow modifiers, colorants.

9. The corrosion-resistant halogen composite material according to claim 8, wherein, The lubricant is one or more of polytetrafluoroethylene, zinc stearate, calcium stearate, talc powder, silicone oil, polyethylene wax.

10. The preparation method of a halogen-resistant corrosion composite material according to claim 1, characterized in that, Including the following steps: (1) Weigh each component by weight; (2) Pre-mix the raw materials except the modified carbon fiber evenly and add them from the main feeding port of the twin-screw extruder, and the modified carbon fiber is added through the side feeding port; (3) Melt, extrude, and pelletize to obtain the halogen-resistant corrosion composite material.

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