Chumulus scandens compound steel bar corrosion inhibitor as well as preparation method and application thereof
Through the compounding technology of grass extract, potassium hydrogen phosphate and sodium dodecyl sulfonate, the steel bar rust resistor made solves the problems of high compounding cost and poor environmental friendliness in the existing technology, achieving a low-cost, efficient and environmentally friendly steel bar rust resistance effect, and significantly improving the durability of the reinforced concrete structure.
Patent Information
- Application Number
- CN202510064913.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-15
- Publication Date
- 2025-05-09
AI Technical Summary
The existing mixed rust resistors are difficult to meet the corrosion resistance needs of reinforced concrete structures such as coastal bridges that are severely eroded by chloride ions.
The steel bar rust resistor made of grass extract, potassium hydrogen phosphate and sodium dodecyl sulfonate is used to form a stable protective film through the synergistic effect of these components, and improve the corrosion resistance of the steel bars.
It achieves a low-cost, efficient and environmentally friendly steel bar rust resistance effect, significantly improves the durability of the reinforced concrete structure, and is suitable for engineering reinforced concrete structures that are severely eroded by chloride ions.
Smart Images
Figure CN119954433A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of construction technology, and in particular to a Lecao compound steel bar rust inhibitor and a preparation method and application thereof. Background Art
[0002] In chloride-rich environments, steel corrosion is the main cause of corrosion damage to reinforced concrete structures. Therefore, improving the corrosion resistance of steel bars in concrete structures in chloride environments is a key and urgent issue.
[0003] Among the various effective methods to prevent steel corrosion in concrete structures, the use of rust inhibitors is one of the simplest and most economical methods. Currently, commonly used rust inhibitors can be divided into three categories according to their ingredients: inorganic (chromates, nitrites, and phosphates, etc.), organic (amines and alkanolamines, etc.) and mixed rust inhibitors. However, the use of inorganic rust inhibitors is prone to pollute the environment, and the cost of preparing organic rust inhibitors is high. Mixed rust inhibitors are usually obtained by compounding two or more components. When used, the synergistic effect between different components can be used to improve the rust inhibition effect. However, the commonly used mixed rust inhibitors at this stage generally have problems such as high compounding cost, poor environmental friendliness during application, and difficulty in degradation. Therefore, finding a low-cost, efficient and green compound steel rust inhibitor has become a hot research in the field of engineering materials.
[0004] Lespedeza is a widely distributed plant with strong reproductive capacity, and is often regarded as a harmful weed in agricultural production. However, the whole plant of Lespedeza is rich in a variety of active compounds such as flavonoids, sterols, terpenes, alkaloids and volatile oils. Among them, flavonoids have a high content, are easy to extract, non-toxic, and easily degradable. They have super-delocalization and a specific spatial conformation. They can chelate with metal ions to form a stable protective film and show good rust inhibition performance. Therefore, Lespedeza extract has important potential in the development of green rust inhibitors.
[0005] However, for reinforced concrete structures such as coastal bridges that are severely corroded by chloride ions, the steel bar rust inhibitor whose effective rust-inhibiting ingredient only contains clematis extract has strict requirements on dosage. At low dosages, the protective film layer formed on the surface of the steel bar is not stable and durable enough, and has poor dispersibility in the concrete medium. The rust-inhibiting performance is not stable enough, making it difficult to meet actual engineering needs. Summary of the invention
[0006] The present application proposes a compound steel bar rust inhibitor of Lecao, which comprises, by mass, 20 to 40 parts of Lecao extract, 5 to 10 parts of potassium hydrogen phosphate, 1 to 2 parts of sodium dodecyl sulfate, and 20 to 40 parts of water.
[0007] Among them, the components of the herb extract include 5,7-dihydroxy-2-(4-hydroxyphenyl)-6,8-bis[(2S,3R,4R,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxacyclohexane-2-yl]benzopyran-4-one and 3-[(2S,3R,4S,5S,6R)-4,5-dihydroxy-6-(hydroxymethyl)-3-[(2S,3R,4R,5R,6S)-3,4,5-trihydroxy-6-methyloxacyclohexane-2-yl]oxyoxacyclohexane-2-yl]oxy-2-(3,4-dihydroxyphenyl)-5,7-dihydroxybenzo-4-one.
[0008] The present application also proposes a method for preparing a Herba Lycopodii extract, comprising the following steps: S1: Selecting a raw material of Lecao, grinding and sieving it to obtain Lecao powder; S2: adding the powder of the herb to an ethanol solution according to a certain liquid-to-solid ratio, and obtaining a suspension after soaking and ultrasonic treatment; S3: mixing the suspension with an ethanol solution in a certain volume ratio, performing reflux extraction and vacuum filtration to obtain a filtrate; S4: The filtrate is evaporated and freeze-dried to obtain the Herba Lycopodii extract.
[0009] Among them, in the step S1, the raw material of the grass is cleaned and dried before grinding, the cleaning liquid used for cleaning is distilled water, and the raw material is dried in an oven after cleaning.
[0010] Wherein, in step S1, the powder of Lecao is pretreated, the powder of Lecao is added into petroleum ether according to a certain liquid-to-solid ratio, refluxed for defatting, the petroleum ether is filtered out, and the filter residue is dried to obtain the pretreated powder of Lecao.
[0011] Wherein, in step S1, when the sedge powder is pretreated, the liquid-to-solid ratio of the sedge powder and petroleum ether is (5 ~ 10) mL: 1 g, the number of reflux degreasing is 2 ~ 3 times, and the time of each reflux degreasing is 45 ~ 60 min.
[0012] Wherein, in step S2, the ratio of the herbaceous grass powder to the ethanol liquid is (20-30) mL: 1 g, the volume fraction of the ethanol solution is 70-80%, and the soaking time is 2-3 h.
[0013] Wherein, the volume ratio of the suspension to the ethanol solution in step S3 is, by volume fraction, 10 parts of the suspension: 1 to 2 parts of 80% ethanol solution, and the reflux extraction is performed 3 to 4 times at a temperature of 70 to 75° C., and the time for each reflux extraction is 70 to 80 minutes.
[0014] Wherein, in step S4, the filtrate is placed in a rotary evaporator for heating and evaporation to obtain a viscous liquid, and the viscous liquid is placed in a freeze dryer for vacuumization and freeze drying to obtain the Herba Lycopodii extract.
[0015] The present application also proposes an application of a compound steel bar rust inhibitor of Lecao, wherein the compound steel bar rust inhibitor of Lecao is used to delay steel bar corrosion.
[0016] The compound steel bar rust inhibitor of Lecao in the present application realizes the high-value utilization of Lecao. It has low cost, excellent rust inhibition effect and good environmental protection. It provides a new solution for improving the durability of reinforced concrete structures, and at the same time promotes the high-value utilization of Lecao, a waste plant resource. The compound steel bar rust inhibitor of Lecao in the present application is easy to use and can be directly added to concrete, effectively solving the problems of high compounding cost and difficult degradation of existing mixed rust inhibitors. It can be widely used in reinforced concrete structures of projects such as coastal bridges that are severely corroded by chloride ions, effectively enhancing the corrosion resistance of steel bars and significantly improving the durability of reinforced concrete structures. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] By reading the detailed description below with reference to the accompanying drawings, the above and other purposes, features and advantages of the exemplary embodiments of the present disclosure will become readily understood. In the accompanying drawings, several embodiments of the present disclosure are shown in an exemplary and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein: Figure 1 is the base peak ion chromatogram of the Herba Lycopodii extract in the examples of the present application; Figure 2 It is the electrochemical impedance spectra of the steel bar electrodes of the test sample 1, the test sample 2 and the control group in the embodiment of the present application; Figure 3 It is a Tafel potentiodynamic polarization curve diagram of test sample 1, test sample 2 and control group in the embodiment of the present application. DETAILED DESCRIPTION
[0018] The following will be combined with the drawings in the embodiments of the present disclosure to clearly and completely describe the technical solutions in the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present disclosure.
[0019] A compound steel bar rust inhibitor of lecao, comprising lecao extract, potassium hydrogen phosphate, sodium dodecyl sulfonate and water, comprising 20 to 40 parts of lecao extract, 5 to 10 parts of potassium hydrogen phosphate, 1 to 2 parts of sodium dodecyl sulfonate and 20 to 40 parts of water by weight. The preferred weight ratio is 30 parts of lecao extract, 5 parts of potassium hydrogen phosphate, 1 part of sodium dodecyl sulfonate and 30 parts of water. The parameters of some raw materials can be adjusted according to actual conditions and are not limited here.
[0020] The Lecao compound steel bar rust inhibitor of the present application effectively improves the comprehensive performance of the rust inhibitor by compounding potassium hydrogen phosphate and sodium dodecyl sulfate with Lecao extract.
[0021] The compound steel bar rust inhibitor of Lecao in this embodiment shows excellent rust-proof performance through the synergistic effect of the three components, especially in harsh application environments such as reinforced concrete projects that are severely corroded by chloride ions. The low cost, excellent rust-proof effect and good environmental protection provide a new solution for improving the durability of reinforced concrete structures, and at the same time promote the high-value utilization of the waste plant resource Lecao.
[0022] Furthermore, the main components of the Herba Lysimachiae extract in the embodiments of the present application include 5,7-dihydroxy-2-(4-hydroxyphenyl)-6,8-bis[(2S,3R,4R,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxacyclohexane-2-yl]benzopyran-4-one and 3-[(2S,3R,4S,5S,6R)-4,5-dihydroxy-6-(hydroxymethyl)-3-[(2S,3R,4R,5R,6S)-3,4,5-trihydroxy-6-methyloxacyclohexane-2-yl]oxyoxacyclohexane-2-yl]oxy-2-(3,4-dihydroxyphenyl)-5,7-dihydroxybenzo-4-one.
[0023] The potassium hydrogen phosphate in the embodiment of the present application can form a dense inorganic protective film on the surface of the steel bar, and exert a synergistic rust-inhibiting effect with the organic film layer formed by the Herba Lycopodii extract, thereby enhancing the stability of the film layer and inhibiting the corrosion of the steel bar by chloride ions. Sodium dodecyl sulfate, as an anionic surfactant, exerts a synergistic effect with the rich flavonoids in the Herba Lycopodii extract, thereby improving the corrosion resistance of the rust inhibitor and improving its dispersibility and durability in the concrete medium.
[0024] The present application embodiment provides a method for preparing a Herba Lycopodii extract, comprising the following steps: S1: Selecting a raw material of Lecao, grinding and sieving it to obtain Lecao powder; S2: adding the powder of the herb to an ethanol solution according to a certain liquid-to-solid ratio, and obtaining a suspension after soaking and ultrasonic treatment; S3: mixing the suspension with an ethanol solution in a certain volume ratio, performing reflux extraction and vacuum filtration to obtain a filtrate; S4: The filtrate is evaporated and freeze-dried to obtain the Herba Lycopodii extract.
[0025] It should be noted that in step S1, the selected raw material of Lecao is fresh whole grass. Before grinding, the raw material of Lecao is washed and dried. The washing liquid used for washing is distilled water, and the raw material is dried in an oven after washing.
[0026] Among them, the cleaning liquid used for cleaning the grass is distilled water, the cleaning times are 4 to 6 times, the temperature of the oven during drying is 55 to 60°C, the drying time is 18 to 25 hours, and the sieve specification for grinding and screening is 100 mesh.
[0027] In this embodiment, the grass powder is further pretreated in step S1, the grass powder is added to petroleum ether according to a certain liquid-to-solid ratio, refluxed for defatting, the petroleum ether is filtered out, and the filter residue is dried to obtain the pretreated grass powder.
[0028] The liquid-to-solid ratio of the grass powder and petroleum ether is (5 ~ 10) mL: 1 g, the number of reflux degreasing is 2 ~ 3 times, and the time of each reflux degreasing is 45 ~ 60 min to ensure the reflux degreasing effect of the grass powder.
[0029] In this embodiment, the volume fraction of the ethanol solution used to soak the scutellaria powder in step S2 is 70-80%, the liquid-to-solid ratio of the scutellaria powder to the ethanol solution is (20-30) mL: 1 g, and the soaking time is 2-3 hours. In order to ensure that the scutellaria powder is evenly dispersed in the ethanol solution and can be fully extracted, this embodiment adopts ultrasonic treatment, the temperature of ultrasonic extraction is 70-80°C, the ultrasonic power is 110-120W, and the ultrasonic extraction is performed 2-4 times, each time for 70-80 minutes.
[0030] Furthermore, in step S3, the volume ratio of the suspension to the ethanol solution is, by volume fraction, 10 parts of the suspension: 1 to 2 parts of 80% ethanol solution, and the reflux extraction is performed at a temperature of 70 to 75° C. for 3 to 4 times, and the time for each reflux extraction is 70 to 80 min.
[0031] In step S4, the filtrate is placed in a rotary evaporator for heating and evaporation to obtain a viscous liquid, and the viscous liquid is placed in a freeze dryer and evacuated to a vacuum level of 200 to 500 Pa. It is further freeze-dried and the temperature of the freeze dryer is reduced to -40 to -55°C. After the holding time is 1 to 2 hours, it is sublimated and dried for 4 to 6 hours at -35 to -30°C and sublimated and dried for 2 to 3 hours at 25 to 35°C to obtain the Herba Lysimachiae extract.
[0032] The preparation method of the herbaceous grass extract provided in this embodiment uses the herbaceous grass as the main raw material, which is low-cost and widely distributed. It is often regarded as a harmful plant because it entangles crops and affects their growth. This application realizes the high-value utilization of herbaceous grass.
[0033] Specific Example 1 - Preparation of Herba Lycopodii Extract.
[0034] This embodiment provides the preparation steps of the Herba Lycopodii extract, comprising: Fresh whole grass of Lecao was selected as the raw material of Lecao, and the raw material of Lecao was washed with distilled water for 5 times to remove impurities such as surface soil, placed in an oven at 55°C for 20 hours, dried, ground and sieved through a 100-mesh sieve to remove particles with larger particle size, and Lecao powder was obtained.
[0035] The powder of Lecao was added into petroleum ether at a liquid-to-solid ratio of 5 mL: 1 g, and refluxed for degreasing twice, each time for 50 min. The petroleum ether was filtered off, and the filter residue was dried to obtain the pretreated Lecao powder.
[0036] The pretreated Herba Lecao powder was added into 80% ethanol solution at a liquid-to-solid ratio of 20 mL: 1 g, soaked for 3 h, and then placed in an ultrasonic cleaner. Ultrasonic extraction was performed three times at 35 °C with an ultrasonic power of 110 W, each time for 80 min, to obtain a suspension.
[0037] According to the volume fraction, 10 parts of the suspension were mixed with 2 parts of 80% ethanol solution, refluxed and extracted at 75°C for 3 times, each time for 80 min, and filtered under reduced pressure to obtain a filtrate.
[0038] The filtrate was placed in a rotary evaporator and heated for evaporation to obtain a viscous liquid, which was placed in a freeze dryer and evacuated to 300 Pa. The temperature of the freeze dryer was lowered to -40°C, and after keeping for 2 hours, it was sublimated and dried for 4 hours at -30°C and then sublimated and dried for 3 hours at 30°C to obtain the Herba Lysimachiae extract of this embodiment.
[0039] The steps for identifying the compounds in the extract of Herba Lycopodii are as follows: The substances that may be contained in the herb were searched using databases such as China National Knowledge Infrastructure, Web of Science, and PubMed, and a database containing the name, molecular formula, category, and chemical structure of the relevant compounds was established. Based on UPLC-QTOF-MS technology, the herb extract prepared according to the method of this example was analyzed and identified.
[0040] like Figure 1 As shown, Figure 1 This is the base peak ion chromatogram of the extract of Herba Lycopodii. A total of 15 compounds were identified, including 11 flavonoids, such as Figure 1The sequence numbers 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 and 13 are 5,7-dihydroxy-2-(4-hydroxyphenyl)-6,8-bis[(2S,3R,4R,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxacyclohexane-2-yl]benzopyran-4-one, 3-[(2S,3R,4S,5S,6R)-4,5-dihydroxy-6-(hydroxymethyl)-3-[(2S,3R,4R,5R,6S)-3,4,5-trihydroxy-6-methyloxacyclohexane-2-yl]oxyoxacyclohexane-2-yl]oxy-2-(3,4-dihydroxyphenyl)-5,7-dihydroxybenzo-4-one, and 5-hydroxy-2-(4-hydroxyphenyl)-7-[(2 2-(3,4-dihydroxyphenyl)-5,7-dihydroxy-3-[(2S,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-3-[(2S,5S)-3,4,5-trihydroxy-6-[[(2R,4S,5R)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxymethyl]oxan-2-yl]oxybenzopyran-4-one, 2-(3,4-dihydroxyphenyl)-5,7-dihydroxy-3-[(2S,3R,4S,5S,6R)-3,4,5-trihydroxy-6-[[(2R,3R,4R,5R,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxymethyl]oxan-2-yl]oxan-4-one, benzopyran-4-one, 5,7-dihydroxy-2-(4-hydroxyphenyl)-3-[(2S,3R,4S,5S,6R)-3,4,5-trihydroxy-6-[[(2R,3R,4R,5R,6S)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxymethyl]oxan-2-yl]oxybenzopyran-4-one, 2-(3,4-dihydroxyphenyl)-5-hydroxy-7-[(2S,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxymethyl]oxan-2-yl]oxybenzopyran-4-one -yl]oxybenzopyran-4-one, 5-hydroxy-2-(4-hydroxyphenyl)-3,7-bis[[(2S,3R,4R,5R,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxy]benzopyran-4-one, 5-hydroxy-2-(4-hydroxyphenyl)-7-[(2S,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxybenzopyran-4-one, 5-hydroxy-2-(4-hydroxyphenyl)-7-[(2S,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxybenzopyran-4-one, 2-(3,4-dihydroxyphenyl)-5,7-Dihydroxybenzofuran-4-one. Figure 2 The compounds represented by sequence numbers 1, 2, 14 and 15 are (1S, 3R, 4R, 5R)-3-[[3-(3,4-dihydroxyphenyl)-1-oxo-2-propenyl]oxy]-1,4,5-trihydroxycyclohexanecarboxylic acid, β-(3,4-dihydroxyphenyl)acrylic acid, (E, E)-9-oxooctadec-10,12-dienoic acid and 8-[(2R, 3S)-3-[(Z)-oct-2-enyl]oxacyclohexane-2-yl]octanoic acid, respectively.
[0041] UPLC-QTOF-MS testing confirmed that the Herba Lycopodii extract obtained by the above method contained rich flavonoid compounds. In addition, a certain amount of phenolic acid substances were further detected through experimental testing. These compounds contain rich hydroxyl groups and are easily adsorbed on the metal surface, exerting excellent rust inhibition effects. The above experimental data further confirmed that the Herba Lycopodii in this application is an ideal raw material for a highly efficient, green, synthetic-free steel bar rust inhibitor.
[0042] Specific test example - preparation of Lecao compound steel bar rust inhibitor and its performance testing.
[0043] In order to further verify the rust inhibition effect of the compound steel bar rust inhibitor of Lecao provided in the examples of the present application, in this test example, 30 parts of Lecao extract prepared in Example 1 of the present application, 5 parts of potassium hydrogen phosphate, 1 part of sodium dodecyl sulfate, and 30 parts of water were mixed evenly by mass to serve as the compound steel bar rust inhibitor of Lecao.
[0044] The Lecao compound steel bar rust inhibitor was added into the simulated concrete pore solution in different addition amounts to prepare test sample 1, test sample 2 and a control group. The corrosion performance of test sample 1, test sample 2 and the control group was tested, and then the rust inhibition performance of the Lecao compound steel bar rust inhibitor on steel bars with different addition amounts was evaluated.
[0045] Preparation of test sample 1: Cut a cylindrical Q235 steel bar with a diameter of 8.0 mm and a height of 10.0 mm, place it in a PVC pipe, fill the gap between the steel bar block and the PVC pipe with epoxy resin, then select a plane of the steel bar block as the working surface, polish it step by step with sandpaper, wash it with distilled water, and degrease it with ethanol to make the working surface mirror-like; adjust the pH of saturated calcium hydroxide solution at 25°C to 12.0 with phosphoric acid solution and sodium hydroxide solution to simulate the concrete pore solution; add the Lecao compound steel bar rust inhibitor prepared according to the above method to the simulated concrete pore solution at a mass fraction of 0.050% to prepare test sample 1, seal the test sample 1, and conduct a corrosion performance test.
[0046] Preparation of test sample 2: Cut a cylindrical Q235 steel bar with a diameter of 8.0 mm and a height of 10.0 mm, place it in a PVC pipe, fill the gap between the steel bar block and the PVC pipe with epoxy resin, then select a plane of the steel bar block as the working surface, polish it step by step with sandpaper, wash it with distilled water, and degrease it with ethanol to make the working surface mirror-like; adjust the pH of saturated calcium hydroxide solution at 25°C to 12.0 with phosphoric acid solution and sodium hydroxide solution to simulate the concrete pore solution; add the Lecao compound steel bar rust inhibitor prepared according to the above method to the simulated concrete pore solution at a mass fraction of 0.150% to prepare test sample 2, seal test sample 2, and conduct corrosion performance test.
[0047] Preparation of the control group: a cylindrical Q235 steel bar with a diameter of 8.0 mm and a height of 10.0 mm was cut and placed in a PVC pipe. The gap between the steel bar block and the PVC pipe was filled with epoxy resin. Then, a plane of the steel bar block was selected as the working surface, which was polished step by step with sandpaper, washed with distilled water, and degreased with ethanol to make the working surface mirror-like. The pH of a saturated calcium hydroxide solution at 25°C was adjusted to 12.0 with a phosphoric acid solution and a sodium hydroxide solution to serve as a simulated concrete pore solution. The simulated concrete pore solution was not added with the Lecao composite steel bar rust inhibitor prepared according to the above method. This sample was used as the control group and the corrosion performance test was also performed.
[0048] This test case uses a CS350 electrochemical workstation, and the test system uses a typical three-electrode system (i.e., steel bar as the working electrode, platinum electrode as the auxiliary electrode, and mercury / mercuric oxide electrode as the reference electrode) to test the electrochemical impedance spectroscopy and Tafel potentiodynamic polarization curve of test sample 1, test sample 2, and the control group. Then, the rust inhibition effect of different amounts of Lecao compound steel bar rust inhibitor on steel bars was evaluated.
[0049] It should be noted that electrochemical impedance spectroscopy is to apply a small amplitude AC potential wave with different frequencies to the electrochemical system, measure the ratio of the AC potential to the current signal (this ratio is the impedance of the system) as the sine wave frequency changes, or the phase angle of the impedance changes as the sine wave frequency changes, and then analyze the electrode materials, solid electrolytes, conductive polymers, and corrosion protection mechanisms. In this experiment, the electrochemical impedance spectroscopy test uses a sinusoidal AC voltage with a disturbance amplitude of 10mV, and the test frequency range is 0.01Hz ~ 10000Hz. The measured data are fitted and sorted using Zview software.
[0050] like Figure 2 As shown, Figure 2It is the Nyquist diagram, which is a representation of the electrochemical impedance spectrum. The Nyquist diagram is plotted with the real part of the impedance as the horizontal coordinate and the imaginary part of the impedance as the vertical coordinate. The larger the radius of the capacitive reactance semicircle of the impedance spectrum, the greater the polarization resistance of the steel bar electrode, and the better the rust removal effect of the corresponding steel bar rust remover.
[0051] Figure 2 The three curves in the middle represent the electrochemical impedance spectra of the steel bar electrodes of test sample 1, test sample 2 and the control group when the mass fraction of NaCl in the test environment is 1.00%. The curve radius of test sample 2 is the largest, the polarization resistance of the steel bar is the largest, and the corrosion resistance is the best. The curve radius of test sample 1 is second, and the curve radius of the control group is the smallest. It can be seen that adding 0.050% or 0.150% of the steel bar rust inhibitor prepared by using Lecao to the simulated concrete pore solution significantly improves the corrosion resistance of the steel bar. The steel bar rust inhibitor prepared by using Lecao has excellent rust inhibition effect on steel bars.
[0052] In the test examples of the present application, the scanning potential of the Tafel potentiodynamic polarization curve test is ±250 mV relative to the open circuit potential, and the scanning rate is 1 mV / s. In order to obtain better results, the Tafel potentiodynamic polarization curve test under each test condition is repeated at least three times.
[0053] like Figure 3 As shown, Figure 3 The three curves represent the Tafel potential polarization curves of test sample 1, test sample 2 and control group when the mass fraction of NaCl in the test environment is 1.00%. The self-corrosion current density of the control group is 0.393μA / cm 2 ; The self-corrosion current density of test sample 1 is 0.022μA / cm 2 , the corrosion inhibition efficiency is 94%; the self-corrosion current density of test sample 2 is 0.104μA / cm 2 , the corrosion inhibition efficiency is 73%.
[0054] The experimental test results show that the two groups of test results have the same pattern. It can be seen that adding 0.050% and 0.150% mass fractions of the Lecao compound steel bar rust inhibitor into the simulated concrete pore solution respectively significantly improves the corrosion resistance of the steel bars. The Lecao compound steel bar rust inhibitor prepared according to the embodiment method of the present application has excellent rust inhibition effect on steel bars.
[0055] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present application.
[0056] Finally, it should be noted that, in this application, relational terms such as first and second, etc., are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article including the elements.
[0057] Specific examples are used in this application to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core idea of this application. At the same time, for those skilled in the art, according to the idea of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on this application.
Claims
1. A compound steel bar rust inhibitor made of Lecao, characterized in that: The compound steel bar rust inhibitor of Lecao includes 20 to 40 parts of Lecao extract, 5 to 10 parts of potassium hydrogen phosphate, 1 to 2 parts of sodium dodecyl sulfate, and 20 to 40 parts of water in parts by mass.
2. The Lecao compound steel bar rust inhibitor according to claim 1, characterized in that: The extract of Herba Lysimachiae includes 5,7-dihydroxy-2-(4-hydroxyphenyl)-6,8-bis[(2S,3R,4R,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxacyclohexane-2-yl]benzopyran-4-one and 3-[(2S,3R,4S,5S,6R)-4,5-dihydroxy-6-(hydroxymethyl)-3-[(2S,3R,4R,5R,6S)-3,4,5-trihydroxy-6-methyloxacyclohexane-2-yl]oxyoxacyclohexane-2-yl]oxy-2-(3,4-dihydroxyphenyl)-5,7-dihydroxybenzo-4-one.
3. A method for preparing a Herba Lycopodii extract, characterized in that: The following steps are involved: S1: Selecting a raw material of Lecao, grinding and sieving it to obtain Lecao powder; S2: adding the herbaceous sedge powder to an ethanol solution according to a certain liquid-to-solid ratio, and obtaining a suspension after soaking and ultrasonic treatment; S3: mixing the suspension with an ethanol solution in a certain volume ratio, performing reflux extraction and vacuum filtration to obtain a filtrate; S4: The filtrate is evaporated and freeze-dried to obtain the Herba Lycopodii extract.
4. The method for preparing the Herba Lycopodii extract according to claim 3, characterized in that: In step S1, the raw material of the grass is cleaned and dried before grinding. The cleaning liquid used for cleaning is distilled water, and the raw material is dried in an oven after cleaning.
5. The method for preparing the Herba Lycopodii extract according to claim 3, characterized in that: In step S1, the powder of the herb is pretreated by adding the herb powder into petroleum ether according to a certain liquid-to-solid ratio, reflux degreasing, filtering out the petroleum ether, and drying the filter residue to obtain the pretreated herb powder.
6. The method for preparing the Herba Lycopodii extract according to claim 5, characterized in that: In step S1, when the sedge powder is pretreated, the liquid-to-solid ratio of the sedge powder and petroleum ether is (5-10) mL: 1 g, the number of reflux degreasing is 2-3 times, and the time of each reflux degreasing is 45-60 min.
7. The method for preparing the Herba Lycopodii extract according to claim 3, characterized in that: In step S2, the ratio of the herbaceous grass powder to the ethanol liquid is (20-30) mL: 1 g, the volume fraction of the ethanol solution is 70-80%, and the soaking time is 2-3 h.
8. The method for preparing the Herba Lycopodii extract according to claim 3, characterized in that: The volume ratio of the suspension to the ethanol solution in step S3 is, by volume fraction, 10 parts of the suspension: 1 to 2 parts of 80% ethanol solution. The reflux extraction is performed at a temperature of 70 to 75° C. for 3 to 4 times, and the time for each reflux extraction is 70 to 80 minutes.
9. The method for preparing the Herba Lycopodii extract according to claim 3, characterized in that: In the step S4, the filtrate is placed in a rotary evaporator for heating and evaporation to obtain a viscous liquid, and the viscous liquid is placed in a freeze dryer for vacuumization and freeze drying to obtain the Herba Lycopodii extract.
10. An application of a compound steel bar rust inhibitor made of Lecao, wherein the compound steel bar rust inhibitor made of Lecao is used to delay steel bar corrosion.