A biomass inorganic hybrid nanocomposite corrosion inhibitor, its preparation method and application

Abstract

This invention belongs to the field of metal corrosion and protection, and discloses a biomass inorganic hybrid nanocomposite corrosion inhibitor, its preparation method, and its application. This invention involves adding a natural carbonyl compound solution to a natural sugar solution to obtain a biomass corrosion inhibitor; then, the biomass corrosion inhibitor is reacted with nano-metal oxides to obtain the biomass inorganic hybrid nanocomposite corrosion inhibitor. The reaction raw materials of this invention are simple, readily available, green, non-toxic, and environmentally friendly; the prepared biomass inorganic hybrid nanocomposite corrosion inhibitor is suitable for neutral conditions, and dispersing the corrosion inhibitor in boiler water and circulating cooling water shows good metal corrosion inhibition effects, demonstrating excellent application prospects.

Description

Technical Field

[0001] This invention belongs to the field of metal corrosion and protection, and specifically relates to a biomass inorganic hybrid nanocomposite corrosion inhibitor, its preparation method and application. Background Technology

[0002] With the continuous advancement of industrialization and modernization, people's demand for metal products in production and daily life is also constantly increasing. However, metal products are generally prone to oxidation and corrosion. Corrosion not only leads to a rapid decline in mechanical properties but also creates safety hazards, potentially causing substantial economic losses and even threatening personal safety, severely impacting normal production and daily life. Therefore, how to prevent metal corrosion has become a crucial issue.

[0003] Currently, there are various metal protection technologies. Among them, the method of adding corrosion inhibitors to metals to slow down corrosion has the advantages of low cost, convenient use, easy transportation, and no need to change the original metal composition. Corrosion inhibitors are substances that can significantly reduce the corrosion rate of metals. Many chemical substances or structures have good corrosion inhibition properties, such as chromates, nitrites, thiol benzothiazoles, sulfonated lignin, and polyaspartic acid. According to chemical composition, they can be classified into inorganic corrosion inhibitors, organic corrosion inhibitors, and polymer corrosion inhibitors; according to media conditions, they can be classified into neutral media (boiler water, circulating cooling water), acidic media, and gaseous media (gas phase corrosion inhibitors).

[0004] In recent years, environmental awareness has gradually deepened, and corrosion inhibitors that meet the requirements of green chemistry are gradually replacing highly toxic and polluting ones. Among these, amino-containing organic compounds have enormous application potential. On the one hand, amino groups are widely present in natural biological macromolecules, possessing safe and environmentally friendly properties. On the other hand, corrosion inhibition efficiency is closely related to the strength of the adsorption between the organic corrosion inhibitor and the metal surface; amino-containing organic compounds have active sites that can chelate with metals, providing good protection against metal corrosion. However, most amino-containing organic compounds have poor solubility in water, which greatly affects their corrosion inhibition performance. Summary of the Invention

[0005] In order to overcome the shortcomings and deficiencies of the prior art, the primary objective of this invention is to provide a method for preparing a biomass inorganic hybrid nanocomposite corrosion inhibitor.

[0006] Another objective of this invention is to provide a biomass inorganic hybrid nanocomposite corrosion inhibitor prepared by the above method.

[0007] Another objective of this invention is to provide the application of the above-mentioned biomass inorganic hybrid nanocomposite corrosion inhibitor in metal corrosion protection.

[0008] The reaction raw materials are simple, readily available, green, non-toxic, and environmentally friendly. The prepared biomass inorganic hybrid nanocomposite corrosion inhibitor is suitable for neutral conditions. Dispersing the corrosion inhibitor of this invention in boiler water and circulating cooling water shows good metal corrosion inhibition effect and has excellent application prospects.

[0009] The objective of this invention is achieved through the following solution:

[0010] A method for preparing a biomass inorganic hybrid nanocomposite corrosion inhibitor includes the following steps:

[0011] 1) Preparation of biomass corrosion inhibitors:

[0012] A solution of a natural carbonyl compound was added to a solution of a natural sugar, the mixture was stirred and reacted, and then centrifuged, washed, and dried to obtain an organic corrosion inhibitor.

[0013] 2) Preparation of biomass inorganic hybrid nanocomposite corrosion inhibitors:

[0014] The organic corrosion inhibitor obtained in step 1) was stirred and dispersed in water. After uniform dispersion, the nano-metal oxide was added to the organic corrosion inhibitor solution, stirred and reacted, and then centrifuged, washed and dried to obtain the biomass inorganic hybrid nanocomposite corrosion inhibitor.

[0015] The natural carbonyl compounds are aldehydes or acid anhydrides derived from biological materials.

[0016] Step 1) The natural carbonyl compound is at least one of citral, o-vanillin, syringaldehyde, and n-octenyl succinic anhydride.

[0017] Step 1) The natural sugar is at least one of chitin, chitosan, glucosamine, aminomannose, and muramic acid.

[0018] In step 1), the solvent for the natural sugar solution is an aqueous solution of acetic acid; wherein the concentration of acetic acid is 0.8–1.2 wt%, preferably 1 wt%.

[0019] Step 1) The natural sugar solution is obtained by adding natural sugars to a solvent and stirring at a speed of 200-600 r / min, preferably 400 r / min, for 0.5-1.5 h, preferably 1 h.

[0020] The solvent for the natural carbonyl compound solution in step 1) is anhydrous ethanol, anhydrous acetone, or anhydrous diethyl ether, preferably anhydrous ethanol.

[0021] In step 1), the mass ratio of natural sugars to solvent in the natural sugar solution is 1:(100-200).

[0022] In step 1), the mass ratio of the natural carbonyl compound to the solvent in the natural carbonyl compound solution is 1:(5-20).

[0023] In step 1), the mass ratio of the natural sugar to the natural carbonyl compound is 1:(0.2-1.6), preferably 1:1.

[0024] Step 1) involves adding the natural carbonyl compound solution to the natural sugar solution by dropwise addition, controlled within 0–20 minutes, preferably ending the addition within 10 minutes.

[0025] The reaction temperature in step 1) is 10-30℃; the reaction time is 4-8 hours; and the stirring speed is 200-600 r / min, preferably 400 r / min.

[0026] Step 2) The nano metal oxide is one of nano zinc oxide or nano titanium oxide.

[0027] Step 2) The mass ratio of the organic corrosion inhibitor to water is 1:(500-1500).

[0028] Step 2) The dispersion is ultrasonic dispersion, and the dispersion time is 1 to 5 hours, preferably 3 hours.

[0029] The mass ratio of the organic corrosion inhibitor to the nano metal oxide in step 2) is 1:(0.02-0.1).

[0030] The reaction temperature in step 2) is 10-30℃; the reaction time is 2-5 hours; and the stirring speed is 200-600 r / min, preferably 400 r / min.

[0031] The washing described in steps 1) and 2) is washing with at least one solution, such as water or ethanol.

[0032] The drying temperature in steps 1) and 2) is 45-80℃, preferably 60℃, and the drying time is 12-48h, preferably 24h.

[0033] A biomass inorganic hybrid nanocomposite corrosion inhibitor prepared by the above method.

[0034] Application of the biomass inorganic hybrid nanocomposite corrosion inhibitor in metal corrosion protection.

[0035] The biomass inorganic hybrid nanocomposite corrosion inhibitor is dispersed in boiler water or circulating cooling water to slow down corrosion of boilers or related equipment.

[0036] The mechanism of this invention is as follows:

[0037] (1) The amino groups on natural sugars that swell in acetic acid aqueous solution undergo Schiff base reactions with the carbonyl groups on natural carbonyl compounds to form imine bonds, and the organic corrosion inhibitor eventually precipitates from the solution system. (2) The nano-metal oxides and organic corrosion inhibitors are connected by complexation and hydrogen bonding. On the one hand, this can shift the metal corrosion potential to the positive direction. On the other hand, the abundant hydroxyl groups on the surface of the nano-metal oxides can help the organic corrosion inhibitors disperse in the aqueous solution and improve their solubility.

[0038] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0039] (1) The raw materials for preparing corrosion inhibitors are widely available, inexpensive and readily available, non-toxic and environmentally friendly, and have low preparation costs.

[0040] (2) The conditions for preparing corrosion inhibitors are simple and mild. The reaction environment is an aqueous solution, and there is no need to use a large amount of strong acids, strong bases and organic solvents in the reaction system.

[0041] (3) The prepared corrosion inhibitor has a significantly higher solubility in neutral corrosive media than that of amino-containing organic corrosion inhibitors, and its slow-release effect is also significantly improved, reducing the environmental requirements of amino-containing organic corrosion inhibitors.

[0042] (4) The corrosion inhibitor prepared is less toxic and more in line with the requirements of green chemistry than corrosion inhibitors using non-natural sugars and non-natural carbonyl compounds, and has better corrosion inhibition efficiency. Attached Figure Description

[0043] Figure 1 Infrared spectra of chitosan (CS), octenyl succinic anhydride (OSA), and chitosan-modified octenyl succinic anhydride (OSA-CS) prepared in step 1 of Example. Detailed Implementation

[0044] The present invention will be further described in detail below with reference to embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments used, unless otherwise specified, are all commercially available conventional products.

[0045] Unless otherwise specified, all reagents used in the examples are commercially available.

[0046] Electrochemical tests were performed using a CHI660E electrochemical workstation (Shanghai Chenhua), employing a three-electrode system (the working electrode was a Q235 steel sheet encapsulated with epoxy resin, with an exposed area of ​​1×1 cm). 2The reference electrode was a saturated calomel electrode, and the counter electrode was a platinum sheet electrode. The potentiodynamic polarization scan range was OPC±300mV, the scan rate was 1mV / s, the frequency variation range of the electrochemical impedance spectroscopy was 0.01~100kHz, and the perturbation amplitude was 5mV.

[0047] The electrochemical tests were divided into six groups. The first group used a 3.5 wt.% NaCl aqueous solution (500 mL) as the corrosion medium without adding corrosion inhibitor. The second group used a 3.5 wt.% NaCl aqueous solution (500 mL) with 10 ppm (0.0051 g) of corrosion inhibitor added. The third group used a 3.5 wt.% NaCl aqueous solution (500 mL) with 50 ppm (0.0254 g) of corrosion inhibitor added. The fourth group used a 3.5 wt.% NaCl aqueous solution (500 mL) with 100 ppm (0.0498 g) of corrosion inhibitor added. The fifth group used a 3.5 wt.% NaCl aqueous solution (500 mL) with 150 ppm (0.0757 g) of corrosion inhibitor added. The sixth group used a 3.5 wt.% NaCl aqueous solution (500 mL) with 200 ppm (0.1006 g) of corrosion inhibitor added. Each group was fully immersed in the medium for 72 hours.

[0048] Chitosan: Purchased from Tianjin Damao, with the following specifications: CAS: 9012-76-4, purity: analytical grade AR, degree of deacetylation: ≥90%, MW: ≈200000, viscosity: 100-200 mpa.s, production batch number 20210803;

[0049] Octenyl succinic anhydride: purchased from Wengjiang Reagent, specifications: CAS: 26680-54-6, purity: analytical grade, production batch number: 20210217;

[0050] Nano zinc oxide: purchased from Maclean's, specifications: CAS: 1314-13-2, purity: analytical grade, production batch number: 20201012;

[0051] Pyridine-3-carboxaldehyde: Purchased from Wengjiang Reagent Center, specifications: CAS: 500-22-1, purity: analytical grade, production batch: 20200610

[0052] Example 1:

[0053] 1. Preparation of chitosan-modified n-octenyl succinic anhydride:

[0054] 0.5 g of chitosan was added to 100 g of 1% acetic acid aqueous solution and stirred at 400 r / min for 1 h at room temperature. Then, 5 g of ethanol solution containing 0.5 g of n-octenyl succinic anhydride was slowly added dropwise to the solution, and the addition was completed within 10 min. The reaction was carried out at 25 °C for 6 h. The resulting yellowish-white viscous mixture was centrifuged, and the lower precipitate was washed three times with anhydrous ethanol and deionized water. The precipitate was then dried in an oven at 60 °C for 24 h to obtain yellowish-white powdered chitosan-modified n-octenyl succinic anhydride.

[0055] 2. Preparation of hybrid corrosion inhibitors:

[0056] 0.1g of chitosan-modified n-octenyl succinic anhydride was added to 100g of deionized water and ultrasonically dispersed for 1h. Then, 0.004g of nano zinc oxide was added and stirred at 400r / min for 3h. The mixture was centrifuged, and the lower precipitate was washed three times with deionized water. The mixture was dried at 60℃ for 24h to finally obtain the biomass inorganic hybrid nanocomposite corrosion inhibitor.

[0057] Electrochemical analysis, based on polarization curve testing, yielded corrosion inhibition efficiencies of 95.6%, 95.8%, 96.3%, 96.8%, and 96.9% for the five groups containing corrosion inhibitors. The calculation formulas are as follows:

[0058] In the formula j corr j' represents the corrosion current density without corrosion inhibitor. corr This represents the corrosion current density when a corrosion inhibitor is added.

[0059]

[0060] Example 2:

[0061] 1. Preparation of chitosan-modified n-octenyl succinic anhydride:

[0062] 0.5 g of chitosan was added to 100 g of 1% acetic acid aqueous solution and stirred at 400 r / min for 1 h at room temperature. Then, 5 g of ethanol solution containing 0.5 g of n-octenyl succinic anhydride was slowly added dropwise to the solution, and the addition was completed within 10 min. The reaction was carried out at 25 °C for 6 h. The resulting yellowish-white viscous mixture was centrifuged, and the lower precipitate was washed three times with anhydrous ethanol and deionized water. The precipitate was then dried in an oven at 60 °C for 24 h to obtain yellowish-white powdered chitosan-modified n-octenyl succinic anhydride.

[0063] 2. Preparation of hybrid corrosion inhibitors:

[0064] 0.1g of chitosan-modified n-octenyl succinic anhydride was added to 100g of deionized water and ultrasonically dispersed for 1h. Then, 0.006g of nano zinc oxide was added and stirred at 400r / min for 3h. The mixture was centrifuged, and the lower precipitate was washed three times with deionized water. The mixture was dried at 60℃ for 24h to finally obtain the biomass inorganic hybrid nanocomposite corrosion inhibitor.

[0065] Electrochemical analysis showed that the corrosion inhibition efficiencies of the five groups containing corrosion inhibitors were 96.4%, 96.7%, 96.9%, 97.6%, and 97.8%, respectively.

[0066] Example 3:

[0067] 1. Preparation of chitosan-modified n-octenyl succinic anhydride:

[0068] 0.5 g of chitosan was added to 100 g of 1% acetic acid aqueous solution and stirred at 400 r / min for 1 h at room temperature. Then, 5 g of ethanol solution containing 0.5 g of n-octenyl succinic anhydride was slowly added dropwise to the solution, and the addition was completed within 10 min. The reaction was carried out at 25 °C for 6 h. The resulting yellowish-white viscous mixture was centrifuged, and the lower precipitate was washed three times with anhydrous ethanol and deionized water. The precipitate was then dried in an oven at 60 °C for 24 h to obtain yellowish-white powdered chitosan-modified n-octenyl succinic anhydride.

[0069] 2. Preparation of hybrid corrosion inhibitors:

[0070] 0.1g of chitosan-modified n-octenyl succinic anhydride was added to 100g of deionized water and ultrasonically dispersed for 1h. Then, 0.008g of nano zinc oxide was added and stirred at 400r / min for 3h. The mixture was centrifuged, and the lower precipitate was washed three times with deionized water. The mixture was dried at 60℃ for 24h to finally obtain the biomass inorganic hybrid nanocomposite corrosion inhibitor.

[0071] Electrochemical analysis showed that the corrosion inhibition efficiencies of the five groups containing corrosion inhibitors were 96.3%, 96.9%, 97.2%, 97.8%, and 98.0%, respectively.

[0072] Comparative Example 1

[0073] 1. Preparation of chitosan-modified pyridinaldehyde:

[0074] 0.5 g of chitosan was added to 100 g of 1% acetic acid aqueous solution and stirred at 400 r / min for 1 h at room temperature. Then, 5 g of ethanol solution containing 0.5 g of pyridine-3-carboxaldehyde was slowly added dropwise to the solution. The mixture was then heated to 50 °C and reacted for 5 h. After filtration, washing, and drying, pyridine-3-carboxaldehyde modified chitosan was obtained.

[0075] 2. Preparation of hybrid corrosion inhibitors:

[0076] 0.1 g of pyridine-3-carboxaldehyde modified chitosan was added to 100 g of deionized water and ultrasonically dispersed for 1 h. Then, 0.1 g of nano zinc oxide was added and stirred at 400 r / min for 3 h. The mixture was centrifuged, and the lower precipitate was washed three times with deionized water. The mixture was dried at 60 °C for 24 h to finally obtain the biomass inorganic hybrid nanocomposite corrosion inhibitor.

[0077] Electrochemical analysis showed that the corrosion inhibition efficiencies of the five groups containing corrosion inhibitors were 94.3%, 94.6%, 95.0%, 95.1%, and 95.2%, respectively.

[0078] Depend on Figure 1 It can be seen that, after modification, the organic components of the corrosion inhibitor generated new structural sites, improved the distribution of N and O atoms, exposed more N and O atoms that can form coordination bonds with metal surface atoms, improved the adsorption force between the corrosion inhibitor and the metal, and thus enhanced the corrosion inhibition efficiency.

[0079] Comparing the corrosion inhibition efficiency of Examples 1-3 and Comparative Example 1, it can be seen that Examples 1-3, which use n-octenyl succinic anhydride, can prepare biomass inorganic hybrid nanocomposite corrosion inhibitors with good corrosion inhibition effect when the amount of nano-metal oxide is small, which greatly reduces the raw material cost. At the same time, the corrosion inhibition efficiency is also better than that of the comparative example, and it has good application prospects.

[0080] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for preparing a biomass inorganic hybrid nanocomposite corrosion inhibitor, characterized in that... Includes the following steps: 1) Preparation of biomass corrosion inhibitors: A solution of a natural carbonyl compound was added to a solution of a natural sugar, the mixture was stirred and reacted, and then centrifuged, washed, and dried to obtain an organic corrosion inhibitor. The mass ratio of the natural sugars to the natural carbonyl compounds is 1:1; The reaction temperature is 10-25℃; the reaction time is 4-8 hours. The natural sugar is chitosan; 2) Preparation of biomass inorganic hybrid nanocomposite corrosion inhibitors: The organic corrosion inhibitor obtained in step 1) was stirred and dispersed in water. After the dispersion was uniform, the nano metal oxide was added to the organic corrosion inhibitor solution, stirred and reacted, and after centrifugation, washing and drying, the biomass inorganic hybrid nanocomposite corrosion inhibitor was obtained. The natural carbonyl compound is n-octenyl succinic anhydride; The mass ratio of the organic corrosion inhibitor to the nano-metal oxide is 1:(0.02-0.1). The nano-metal oxide is one of nano-zinc oxide or nano-titanium oxide.

2. The preparation method according to claim 1, characterized in that: Step 1) The mass ratio of natural sugars to solvent in the natural sugar solution is 1:(100~200); Step 1) The mass ratio of the natural carbonyl compound to the solvent in the natural carbonyl compound solution is 1:(5~20).

3. The preparation method according to claim 1, characterized in that: The stirring speed in step 1) is 200~600 r / min.

4. The preparation method according to claim 1, characterized in that: Step 2) The mass ratio of the organic corrosion inhibitor to water is 1:(500~1500).

5. The preparation method according to claim 1, characterized in that: Step 2) The reaction temperature is 10-30℃; the reaction time is 2-5 hours; and the stirring speed is 200-600 r / min.

6. A biomass inorganic hybrid nanocomposite corrosion inhibitor prepared by the method described in any one of claims 1 to 5.

7. The application of the biomass inorganic hybrid nanocomposite corrosion inhibitor according to claim 6 in metal corrosion protection.

Images