Preparation method and application of water-soluble quinoline quaternary ammonium salt corrosion inhibitor

Abstract

The invention relates to the technical field of corrosion inhibitors, and discloses a preparation method and application of a water-soluble quinoline quaternary ammonium salt corrosion inhibitor, 2, 2-dimethylolpropionic acid, 4-formylbenzoyl chloride, 6-aminoquinoline and a dibromoalkane compound are subjected to esterification, Schiff base condensation and quaternization reaction, and the polymer-based water-soluble quinoline quaternary ammonium salt corrosion inhibitor is obtained. The corrosion inhibitor has hydrophilic carboxyl and quaternary ammonium salt groups, so that the corrosion inhibitor is endowed with good water solubility, and the slow release performance of the corrosion inhibitor is favorably improved. The quinoline quaternary ammonium salt corrosion inhibitor contains a Schiff base group, has stronger coordination capacity with the surface of a steel sheet than that of a traditional quinoline quaternary ammonium salt corrosion inhibitor, can form a continuous multi-layer compact polymer film layer on the surface of the steel sheet, effectively inhibits the contact between a hydrochloric acid corrosion medium and the surface of the steel sheet, and shows higher corrosion prevention and inhibition performance.

Description

Technical Field

[0001] The invention relates to the technical field of corrosion inhibitors, in particular to a preparation method and application of a water-soluble quinoline quaternary ammonium salt corrosion inhibitor. Background Art

[0002] In oil and gas well production operations, acid fracturing technology is an effective technical measure for increasing oil and gas well production. However, acid has a strong corrosive effect on metals, causing serious corrosion and damage to surface pipelines and wellbore pipe walls. Therefore, it is necessary to add a corrosion inhibitor to the acid. Common corrosion inhibitors include imidazolines, quinoline quaternary ammonium salts, and Schiff bases. Among them, quinoline quaternary ammonium salt corrosion inhibitors have good heat resistance and acid resistance, but they have problems such as poor water solubility. Chinese patent CN110642784B discloses a quinoline diquaternary ammonium salt pickling corrosion inhibitor and a preparation method thereof. The quinoline diquaternary ammonium salt corrosion inhibitor obtained by reacting 6-aminoquinoline, diethyl malonate, and bromoalkane has excellent corrosion inhibition performance. Compared with the small molecule compound corrosion inhibitor of the patent, the polymer corrosion inhibitor has better structural stability, excellent high temperature resistance, and can easily form a dense protective film on the metal surface, thereby achieving better corrosion inhibition effect. Summary of the Invention

[0003] (1) Technical Problems Solved: The present invention solves the problem of poor water solubility and poor corrosion inhibition performance of polymer-based quinoline quaternary ammonium salt corrosion inhibitors.

[0004] (II) Technical Solution: Preparation Method and Application of a Water-Soluble Quinoline Quaternary Ammonium Salt Corrosion Inhibitor:

[0005] Step (1) adding 2,2-dihydroxymethylpropionic acid, 4-dimethylaminopyridine and triethylamine to a solvent, adding 4-formylbenzoyl chloride in an ice-water bath, controlling the mass ratio of 2,2-dihydroxymethylpropionic acid, 4-dimethylaminopyridine, triethylamine and 4-formylbenzoyl chloride to be 100:(4.2-5.2):(170-200):(248-264); stirring the reaction and filtering, adding a sodium carbonate aqueous solution to the filtrate, extracting by oscillation, standing for stratification, taking the organic phase, drying with anhydrous sodium sulfate, filtering, heating for volatilization, cooling for crystallization, and recrystallizing to obtain precursor 1.

[0006] Step (2) Precursor 1, potassium hydroxide, and 6-aminoquinoline in a mass ratio of 100:(14-16):(18-22) are added to ethanol, and after stirring for reaction, hydrochloric acid solution is added dropwise to adjust the pH to 5-6. After filtering, the filtrate is rotary evaporated to remove ethanol, water and dichloromethane are added, and the mixture is shaken for extraction and allowed to stand for stratification. The organic phase is taken, dried over anhydrous sodium sulfate, filtered, heated for volatilization, cooled for crystallization, and recrystallized to obtain precursor 2.

[0007] Step (3) adding the precursor 2 and the dibromoalkane compound in a mass ratio of 100:(28-40) to the solvent, stirring for reaction and then rotary evaporating, washing with petroleum ether and acetone in sequence, and drying to obtain a polymer-based water-soluble quinoline quaternary ammonium salt corrosion inhibitor.

[0008] Preferably, the solvent in step (1) is dichloromethane, chloroform or 1,2-dichloroethane.

[0009] Preferably, the reaction temperature in step (1) is 20-30° C., and the reaction time is 7-10 h.

[0010] Preferably, the reaction temperature in step (2) is 50-65° C., and the reaction time is 6-8 h.

[0011] Preferably, after the stirring reaction in step (2), hydrochloric acid solution is added dropwise to adjust the pH to 6-6.5, and the mass fraction of the hydrochloric acid solution is 10-30%.

[0012] Preferably, the solvent in step (3) is acetonitrile, ethanol or isopropanol.

[0013] Preferably, the reaction temperature in step (3) is 75-85° C., and the reaction time is 48-60 h.

[0014] Preferably, the dibromoalkane compound in step (3) is any one of 1,2-dibromoethane, 1,3-dibromopropane, 1,4-dibromobutane, 1,5-dibromopentane and 1,6-dibromohexane.

[0015] (3) Beneficial technical effects: The present invention uses 2,2-dihydroxymethylpropionic acid, 4-formylbenzoyl chloride, 6-aminoquinoline, and dibromoalkane compounds through simple esterification, Schiff base condensation, and quaternization reaction to obtain a polymer-based water-soluble quinoline quaternary ammonium salt corrosion inhibitor. The polymer-based water-soluble quinoline quaternary ammonium salt corrosion inhibitor has hydrophilic carboxyl groups and quaternary ammonium salt groups, which give the corrosion inhibitor good water solubility and are beneficial to improving its sustained-release performance.

[0016] The quinoline quaternary ammonium salt corrosion inhibitor of the present invention contains a Schiff base group and has a stronger coordination ability with the steel sheet surface than the traditional quinoline quaternary ammonium salt corrosion inhibitor. It can form a continuous multi-layer dense polymer film layer on the steel sheet surface, effectively inhibiting the contact between the hydrochloric acid corrosive medium and the steel sheet surface, and showing higher corrosion protection and inhibition performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is the reaction formula for preparing water-soluble quinoline quaternary ammonium salt corrosion inhibitor.

[0018] Figure 2 This is the infrared spectrum of water-soluble quinoline quaternary ammonium salt corrosion inhibitor. DETAILED DESCRIPTION

[0019] The present invention will be further described in detail below with reference to specific embodiments and accompanying drawings. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to provide a more thorough and comprehensive understanding of the present disclosure.

[0020] Example 1:

[0021] (1) Add 20 g of 2,2-dihydroxymethylpropionic acid, 0.84 g of 4-dimethylaminopyridine, and 38 g of triethylamine to 200 mL of dichloromethane, add 49.6 g of 4-formylbenzoyl chloride in an ice-water bath, stir and react at 25 °C for 8 h, filter, add 300 mL of 8% sodium carbonate aqueous solution to the filtrate, extract by oscillation, let stand and separate, take the organic phase, dry it with anhydrous sodium sulfate, filter, heat and evaporate it in a fume hood, cool and crystallize it, and obtain precursor 1 with a yield of 32.7 g.

[0022] (2) Add 30 g of precursor 1, 4.2 g of potassium hydroxide, and 5.4 g of 6-aminoquinoline to 1.2 L of ethanol, heat to 60 ° C, stir and reflux for 8 h, add 25% by mass hydrochloric acid solution to adjust the pH to 6.5, filter and rotary evaporate the filtrate to remove ethanol, add 700 mL of water and 500 mL of dichloromethane, shake and extract, let stand to separate, take the organic phase, dry it with anhydrous sodium sulfate, filter and heat in a fume hood to evaporate, cool and crystallize to obtain precursor 2 with a yield of 27.3 g.

[0023] (3) Add 30 g of precursor 2 and 10.4 g of 1,4-dibromobutane to 500 mL of acetonitrile, heat to 75 ° C, stir and reflux for 60 h, rotary evaporate, wash with petroleum ether and acetone in sequence, and dry to obtain a polymer-based water-soluble quinoline quaternary ammonium salt corrosion inhibitor with a yield of 31.5 g. The preparation reaction formula is shown in Figure 1 . Figure 2 In the infrared spectrum, 3992cm -1 It is the absorption peak of -OH of carboxyl group, 1728cm -1 It is the absorption peak of carboxyl C=O, 1667cm -1 It is the absorption peak of ester group C=O, 1596cm -1 is the absorption peak of the Schiff base C=N bond, 1389 cm -1 It is quinoline quaternary ammonium salt + Absorption peak of N-CH2.

[0024] Example 2:

[0025] (1) To 250 mL of 1,2-dichloroethane, 20 g (about 149.25 mmol) of 2,2-dihydroxymethylpropionic acid, 1.04 g of 4-dimethylaminopyridine, and 34 g of triethylamine were added. 52.8 g of 4-formylbenzoyl chloride was added in an ice-water bath. The mixture was stirred at 20°C for 10 h, filtered, and 400 mL of a 10% sodium carbonate aqueous solution was added to the filtrate. The mixture was extracted by oscillation and allowed to stand for stratification. The organic phase was taken and dried over anhydrous sodium sulfate. After filtration, it was heated in a fume hood for volatilization and cooled for crystallization to obtain precursor 1 with a yield of 35.1 g.

[0026] (2) Add 30 g of precursor 1, 4.8 g of potassium hydroxide, and 6.6 g of 6-aminoquinoline to 1.5 L of ethanol, heat to 50 ° C, stir and react for 8 h, add 10% by mass fraction hydrochloric acid solution to adjust the pH to 6, filter and rotary evaporate the filtrate to remove ethanol, add 800 mL of water and 600 mL of dichloromethane, shake and extract, let stand to separate, take the organic phase, dry it with anhydrous sodium sulfate, filter it, heat it in a fume hood to evaporate it, cool it and crystallize it to obtain precursor 2 with a yield of 25.2 g.

[0027] (3) Add 30 g of precursor 2 and 12 g of 1,6-dibromohexane to 600 mL of isopropanol, heat to 85 °C, stir and reflux for 48 h, rotary evaporate, wash with petroleum ether and acetone in sequence, and dry to obtain a polymer-based water-soluble quinoline quaternary ammonium salt corrosion inhibitor with a yield of 31.0 g.

[0028] Example 3:

[0029] (1) Add 20 g of 2,2-dihydroxymethylpropionic acid, 0.96 g of 4-dimethylaminopyridine, and 40 g of triethylamine to 250 mL of chloroform, add 50.7 g of 4-formylbenzoyl chloride in an ice-water bath, stir and react at 30 °C for 7 h, filter, add 400 mL of 8% by mass sodium carbonate aqueous solution to the filtrate, extract with oscillation, let stand and separate, take the organic phase, dry it with anhydrous sodium sulfate, filter, heat and evaporate in a fume hood, cool and crystallize, and obtain precursor 1 with a yield of 37.0 g.

[0030] (2) Add 30 g of precursor 1, 4.5 g of potassium hydroxide, and 6.2 g of 6-aminoquinoline to 1.5 L of ethanol, heat to 65 ° C, stir and reflux for 6 h, add 30% by mass fraction hydrochloric acid solution to adjust the pH to 6.5, filter and rotary evaporate the filtrate to remove ethanol, add 800 mL of water and 600 mL of dichloromethane, shake and extract, let stand to separate, take the organic phase, dry it with anhydrous sodium sulfate, filter and heat in a fume hood to evaporate, cool and crystallize to obtain precursor 2 with a yield of 28.8 g.

[0031] (3) Add 30 g of precursor 2 and 8.4 g of 1,2-dibromoethane to 600 mL of ethanol, heat to 75 °C, stir and reflux for 60 h, rotary evaporate, wash with petroleum ether and acetone in sequence, and dry to obtain a polymer-based water-soluble quinoline quaternary ammonium salt corrosion inhibitor with a yield of 28.6 g.

[0032] Comparative Example 1

[0033] (1) Add 5.42 g of quinoline and 4.10 g of 1,4-dibromobutane to 300 mL of acetonitrile, heat to 70 ° C, stir and reflux for 18 h, rotary evaporate, wash with acetone, add the product to acetonitrile, heat in a fume hood for volatilization, cool and crystallize to obtain quinoline quaternary ammonium salt corrosion inhibitor, the structural formula is as follows: .

[0034] Comparative Example 2

[0035] (2) Add 10.1 g of terephthalaldehyde and 5.4 g of 6-aminoquinoline to 900 mL of ethanol, heat to 60 ° C, stir and reflux for 8 hours, add 25% by mass hydrochloric acid solution to adjust the pH to 6.5, filter and rotary evaporate the filtrate to remove ethanol, add 700 mL of water and 500 mL of dichloromethane, shake and extract, let stand and separate, take the organic phase, dry it with anhydrous sodium sulfate, filter and heat in a fume hood to evaporate, cool and crystallize to obtain a precursor with the structural formula .

[0036] (3) Add 17.8 g of the precursor and 10.4 g of 1,4-dibromobutane to 500 mL of acetonitrile, heat to 75 °C, stir and reflux for 60 h, rotary evaporate, wash with petroleum ether and acetone in sequence, and dry to obtain a polymer-based quinoline quaternary ammonium salt corrosion inhibitor.

[0037] Comparative Example 3

[0038] (1) Add 30 g of precursor 2 (prepared in Example 1) and 19.0 g of 1,4-dibromobutane to 500 mL of acetonitrile, heat to 75°C, stir and reflux for 60 h, rotary evaporate, wash with petroleum ether and acetone in sequence, and dry to obtain a quinoline quaternary ammonium salt corrosion inhibitor. The structural formula is as follows:

[0039] .

[0040] Take 80 mg of quinoline quaternary ammonium salt corrosion inhibitor and add it to 1 L of deionized water. Stir it at room temperature for 2 hours. After standing, observe the solubility of the corrosion inhibitor.

[0041] Table 1 Water solubility test of corrosion inhibitors

[0042]

[0043] Quinoline quaternary ammonium salt corrosion inhibitor was added to 1L of 20% hydrochloric acid solution and stirred to prepare a corrosion inhibition solution. A polished and cleaned N80 steel sheet was used as the test substrate. The corrosion inhibition performance was tested using the static hanging plate method according to SY / T 5405-1996 standard. The test temperature was 60°C.

[0044] Table 2 Corrosion inhibition rate test

[0045]

[0046] After testing, the polymer-based quinoline quaternary ammonium salt corrosion inhibitor prepared in Examples 1-3 has hydrophilic carboxyl groups and quaternary ammonium salt groups, which give the corrosion inhibitor good water solubility, which is beneficial to improving its slow-release performance. In addition, the polymer-based quinoline quaternary ammonium salt corrosion inhibitor contains Schiff base groups, and its coordination ability with the steel sheet surface is stronger than that of traditional quinoline quaternary ammonium salt corrosion inhibitors. It forms a continuous multi-layer dense polymer film layer on the surface of the steel sheet, effectively inhibiting the contact between the hydrochloric acid corrosive medium and the steel sheet surface, showing higher anti-corrosion and corrosion inhibition performance, with the highest corrosion inhibition rate reaching 99.3%.

[0047] The quinoline quaternary ammonium salt corrosion inhibitors of Comparative Examples 1 and 2 do not contain a carboxyl group, have poor water solubility, low corrosion inhibition rate, and poor anti-corrosion and slow-release performance.

[0048] The quinoline quaternary ammonium salt corrosion inhibitor prepared in Comparative Example 3 is a small molecule compound, which is difficult to form a continuous multi-layer dense protective film on the surface of the steel sheet, resulting in a large corrosion inhibition rate.

[0049] The embodiments described above only express several implementation methods of the present invention, which are convenient for understanding the technical solutions of the present invention in a specific and detailed manner, but they cannot be understood as limiting the scope of protection of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present invention, several variations and improvements can be made, which all fall within the scope of protection of the present invention. It should be understood that the technical solutions obtained by ordinary technicians in this field through logical analysis, reasoning or limited experiments on the basis of the technical solutions provided by the present invention are all within the scope of protection of the claims attached to the present invention. Therefore, the scope of protection of the patent of the present invention shall be based on the content of the attached claims, and the description and drawings can be used to interpret the content of the claims.

Claims

1. A preparation method and application of a water-soluble quinoline quaternary ammonium salt corrosion inhibitor, characterized in that: The preparation method comprises the following steps: Step (1) adding 2,2-dihydroxymethylpropionic acid, 4-dimethylaminopyridine, and triethylamine to a solvent, adding 4-formylbenzoyl chloride in an ice-water bath, stirring for reaction, and filtering, adding a sodium carbonate aqueous solution to the filtrate, extracting, and recrystallizing to obtain a precursor 1; Step (2) adding precursor 1, potassium hydroxide, and 6-aminoquinoline to ethanol, stirring for reaction, and then adding hydrochloric acid solution dropwise. After filtering, the filtrate is rotary evaporated, extracted, and recrystallized to obtain precursor 2; Step (3) adding the precursor 2 and the dibromoalkane compound to the solvent, stirring for reaction, rotary evaporation, washing, and drying to obtain a water-soluble quinoline quaternary ammonium salt corrosion inhibitor.

2. The preparation method of water-soluble quinoline quaternary ammonium salt corrosion inhibitor according to claim 1, wherein The solvent in step (1) is dichloromethane, chloroform or 1,2-dichloroethane.

3. The preparation method of water-soluble quinoline quaternary ammonium salt corrosion inhibitor according to claim 1, wherein In the step (1), the mass ratio of 2,2-dihydroxymethylpropionic acid, 4-dimethylaminopyridine, triethylamine, and 4-formylbenzoyl chloride is 100:(4.2-5.2):(170-200):(248-264).

4. The preparation method of water-soluble quinoline quaternary ammonium salt corrosion inhibitor according to claim 1, wherein The reaction temperature in step (1) is 20-30° C., and the reaction time is 7-10 h.

5. The preparation method of water-soluble quinoline quaternary ammonium salt corrosion inhibitor according to claim 1, wherein In step (2), the mass ratio of the precursor 1, potassium hydroxide, and 6-aminoquinoline is 100:(14-16):(18-22).

6. The preparation method of water-soluble quinoline quaternary ammonium salt corrosion inhibitor according to claim 1, wherein The reaction temperature in step (2) is 50-65° C., and the reaction time is 6-8 h.

7. The preparation method of water-soluble quinoline quaternary ammonium salt corrosion inhibitor according to claim 1, wherein In the step (2), after the reaction is stirred, a hydrochloric acid solution is added dropwise to adjust the pH to 6-6.5, wherein the mass fraction of the hydrochloric acid solution is 10-30%.

8. The preparation method of water-soluble quinoline quaternary ammonium salt corrosion inhibitor according to claim 1, wherein The solvent in step (3) is acetonitrile, ethanol or isopropanol.

9. The preparation method of water-soluble quinoline quaternary ammonium salt corrosion inhibitor according to claim 1, wherein The reaction temperature in step (3) is 75-85°C and the reaction time is 48-60h.

10. The preparation method of the water-soluble quinoline quaternary ammonium salt corrosion inhibitor according to claim 1, wherein In the step (3), the mass ratio of the precursor 2 to the dibromoalkane compound is 100:(28-40); the dibromoalkane compound is any one of 1,2-dibromoethane, 1,3-dibromopropane, 1,4-dibromobutane, 1,5-dibromopentane, and 1,6-dibromohexane.

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