阅读说明：本技术 一种咪唑衍生物作为新建钢筋混凝土防腐蚀材料的应用 (Application of imidazole derivative as anticorrosive material for newly-built reinforced concrete ) 是由 蒋金洋 王自飞 吴思燕 郑琦 于 2020-06-17 设计创作，主要内容包括：本发明公开一种咪唑衍生物作为新建钢筋混凝土防腐蚀材料的应用,所述咪唑衍生物的化学结构如下式I所示,其中,R选自C8-C16烷基。本发明应用中,在咪唑环上引入极性基团,制成一种羟基功能化的咪唑季铵盐,其能够作为阳离子阻锈剂,通过外加电场作用导入新建混凝土中,对混凝土中的钢筋产生良好的抗腐蚀性能,或者通过自然迁移方式迁移到混凝土中,改善新建混凝土的孔隙率。<Image he="497" wi="577" file="DDA0002543275680000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>(The invention discloses an application of an imidazole derivative as a newly-built reinforced concrete anticorrosive material, wherein the chemical structure of the imidazole derivative is shown as the following formula I, wherein R is selected from C8-C16 alkyl. In the application of the invention, polar groups are introduced on imidazole rings to prepare hydroxyl functionalized imidazole quaternary ammonium salt which can be used as a cationic rust inhibitor, is introduced into newly-built concrete under the action of an external electric field, generates good corrosion resistance on reinforcing steel bars in the concrete, or migrates into the concrete in a natural migration mode to improve the porosity of the newly-built concrete.)

1. The application of the imidazole derivative as a newly-built reinforced concrete corrosion-resistant material is characterized in that the chemical structure of the imidazole derivative is shown as the following formula I:

wherein R is selected from C8-C16 alkyl.

2. The use according to claim 1, wherein R is selected from C₁₂H₂₅-or C₁₆H₃₃-。

3. Use according to claim 1, characterized in that the preparation process of said imidazole derivatives comprises the following steps:

(1) dissolving imidazole and alkyl halide containing 8 to 16 carbon atoms in an organic solvent, then reacting under the conditions of high temperature and high pressure, and drying to obtain an intermediate;

(2) mixing the obtained intermediate with 2-bromoethanol in an organic solvent, transferring the mixture into a reaction kettle, reacting at high temperature and high pressure, and drying to obtain the imidazole derivative.

4. The use according to claim 3, wherein in step (1), the imidazole and the alkyl halide which participate in the reaction are mixed in a molar ratio of 1:0.5, the reaction temperature is 120-150 ℃, and the reaction time is 12-24 h.

5. The use according to claim 3, wherein, in step (2), the ratio of the intermediate to 2-bromoethanol is 1: (1-1.2) mixing, wherein the reaction temperature is 90-120 ℃, and the reaction time is 4-6 h.

6. The use according to claim 1, characterized in that the imidazole derivatives are used for preventing corrosion of newly built reinforced concrete.

7. The application of claim 6, wherein the rust inhibitor is dissolved in an alkaline concrete simulated hole solution and permeates into newly-built reinforced concrete in a natural migration mode when being applied, so that concrete pores in the newly-built reinforced concrete are improved.

8. The application of claim 6, wherein the rust inhibitor is dissolved in an alkaline concrete simulated hole solution and is introduced into newly-built reinforced concrete in an acceleration mode by an external power supply to improve the corrosion resistance of the steel bars during application.

Technical Field

The invention belongs to the field of building materials, and particularly relates to application of an imidazole derivative as a newly-built reinforced concrete anticorrosive material.

Background

With the wide application of the reinforced concrete in the marine environment, because the reinforced concrete inevitably has pores, salts, especially chloride ions, which are rich in seawater easily enter the interior of the reinforced concrete, so that the reinforced concrete faces severe corrosion risks, and because the corrosion of the reinforced concrete starts from the interior, the reinforced concrete is often corroded, so that the structural performance of the reinforced concrete is reduced or even damaged, the service performance and service life of marine buildings are greatly limited, and further the safety accidents and economic losses are obviously increased. Therefore, the prevention of the corrosion of the steel bars becomes a key point from the source, wherein the use of the steel bar rust inhibitor is the most convenient and effective method with good economical efficiency.

At present, the steel bar rust inhibitor has various types, and can be divided into inorganic, organic and composite types according to chemical components. Inorganic rust inhibitors, most commonly used as nitrites, have been widely used in engineering and construction, but have little possibility of being continuously applied in large scale due to carcinogenic effect contained in the dissolved substances; the organic rust inhibitor is most commonly used in the form of alcamines, and prevents and delays the corrosion of the steel bars by forming a monomolecular layer adsorption film on the surfaces of the steel bars, but researches show that the organic rust inhibitor has very limited permeability and migration capacity in concrete, so that the real rust inhibiting effect is not ideal; in summary, the steel bar rust inhibitor which is green and environment-friendly and has excellent migration capability is the current research hotspot.

For newly-built reinforced concrete structures, the traditional reinforcing steel bar rust inhibitor is generally added into newly-mixed concrete in a mode of adding water for mixing, or the rust inhibitor is used as an anticorrosive coating and brushed on the surface of the concrete to enter the interior of the concrete and the surface of reinforcing steel bars in a permeation and diffusion mode, but the traditional reinforcing steel bar rust inhibitor is limited by the natural migration capability of the existing reinforcing steel bar rust inhibitor, and the anticorrosive effect needs to be improved; on the other hand, the gap between the steel bar and the concrete matrix is a necessary condition for steel bar corrosion, so that the gap between the steel bar and the concrete matrix in the newly-built reinforced concrete is reduced, the infiltration amount of a corrosion medium can be directly reduced, and the corrosion of the steel bar is further relieved. In consideration of the two points, the development of the novel steel bar rust inhibitor which is green, can improve the concrete pores and has strong migration capacity can prevent the corrosion of the steel bars with multiple effects.

Disclosure of Invention

The purpose of the invention is as follows: in order to overcome the defects of the application of the existing reinforcing steel bar rust inhibitor, the invention provides a new application of a green organic rust inhibitor which has better solubility and strong migration capability in an alkaline concrete simulation liquid, and the green organic rust inhibitor is applied to newly-built reinforcing steel bar concrete in a natural migration and external power supply mode, and has an obvious effect.

The technical scheme is as follows: in order to achieve the purpose, the invention adopts the following technical scheme:

the application of the imidazole derivative as a newly-built reinforced concrete anticorrosion material is characterized in that the chemical structure of the imidazole derivative is shown as the following formula I:

wherein R is selected from C8-C16 alkyl.

Preferably, the method comprises the following steps:

r is selected from C₁₂H₂₅-or C₁₆H₃₃The alkyl groups include linear or branched alkyl groups.

The preparation method of the imidazole derivative comprises the following steps:

(1) dissolving imidazole and alkyl halide containing 8 to 16 carbon atoms in an organic solvent, reacting under the condition of high temperature and high pressure, and drying to obtain an intermediate;

(2) mixing the obtained intermediate with 2-bromoethanol in an organic solvent, transferring the mixture into a reaction kettle, reacting at high temperature and high pressure, and drying to obtain the imidazole derivative.

In the step (1), imidazole and alkyl halide which participate in the reaction are mixed according to a molar ratio of 1:0.5, the reaction temperature is 120-150 ℃, and the reaction time is 12-24 h.

In the step (2), the intermediate and 2-bromoethanol are mixed according to a molar ratio of 1: (1-1.2) mixing, wherein the reaction temperature is 90-120 ℃, and the reaction time is 4-6 h.

The imidazole derivative is applied to preventing corrosion of newly-built reinforced concrete. When the corrosion inhibitor is specifically applied, the corrosion inhibitor is dissolved in an alkaline concrete simulated hole solution and enters the reinforced concrete in a natural migration or external power supply acceleration mode, and the porosity and the corrosion resistance of newly-built reinforced concrete are improved.

The imidazole derivative provided by the invention is a hydroxyl functionalized imidazole ionic liquid, is a functional organic matter consisting of anions and cations, is a novel environment-friendly solvent, has excellent physical and chemical properties such as high conductivity, strong thermal stability, difficult volatilization, high solubility, controllable polarity and the like, and is widely applied to the fields of extraction separation, organic synthesis, electrochemistry, catalysis and the like. The functionalized imidazole ionic liquid can realize effective rust resistance on the reinforcing steel bar by introducing a polar group with strong adsorbability.

Therefore, in the application of the invention, polar groups are introduced on imidazole rings to prepare the hydroxyl functionalized imidazole ionic liquid which can be used as an organic rust inhibitor, has good corrosion inhibition performance on different metal materials, especially reinforcing steel bars, and simultaneously has good conductivity and solubility.

Has the advantages that: compared with the prior art, the application of the invention has the following advantages:

(1) in consideration of atomic elements and molecular structure, the imidazole derivative provided by the invention contains N, O heteroatoms in related components, has polar hydroxyl groups, is easy to form chelate with Fe, and enhances the adsorption capacity of rust-resisting components on the surface of a steel bar, thereby forming a steel bar protective film.

(2) From the use point of view, the imidazole derivative provided by the invention has good solubility in an alkaline concrete simulated pore solution, can migrate into reinforced concrete in a natural migration or external current mode, and improves the porosity of newly-built reinforced concrete and prevents corrosion.

(3) From the sustainable development perspective, the imidazole derivative provided by the invention is green and environment-friendly, most of materials required by preparation are simple and easy to obtain, the purchase is convenient, and the cost is low.

Drawings

FIG. 1 is an infrared spectrum of an imidazole derivative of the present invention.

FIG. 2 is a schematic view of an apparatus for applying the imidazole derivatives of the present invention as an anticorrosive material to newly constructed reinforced concrete.

FIG. 3 is a graph of porosity before and after migration of organic rust inhibitor in the newly constructed reinforced concrete of example 1 (example 1).

FIG. 4 is a comparative electrochemical impedance spectrum of the organic rust inhibitor in the newly-built reinforced concrete of example 2 (example 2) before and after migration.

Detailed Description

For a better illustration of the invention, the following are given as examples: