1. The terpyridine primary amine organic corrosion inhibitor is characterized in that the structural formula of the corrosion inhibitor is as follows:，

wherein R represents C₈-C₁₅Olefin or benzene aromatic hydrocarbon with benzene ring number not more than 3.

2. The organic corrosion inhibitor of primary amines of terpyridine of claim 1, wherein R is (CH)₂)₈、(CH₂)₁₀、(CH₂)₁₂、(CH₂)₁₅、(CH₂)₄-C₆H₄-(CH₂)₄、(CH₂)₄-C₆H₄-CH₂-C₆H₄-(CH₂)₄Or (CH)₂)₄-C₆H₄-CH₂-C₆H₄-CH₂-C₆H₄- (CH₂)₄Any one of them.

3. The preparation method of the terpyridine primary amine organic corrosion inhibitor as described in claim 1 or 2, comprising the following steps:

(1) carrying out substitution reaction on 4 ' (4-hydroxyphenyl) -2,2 ', 2 ' -terpyridine and bromoalkyl phthalimide, and purifying a reaction product to obtain an intermediate product;

(2) and (3) adding hydrazine hydrate into the intermediate product by taking alcohol as a solvent to react for 2-3h at the temperature of 75-85 ℃, adding dichloromethane to filter insoluble substances, and removing dichloromethane by rotary evaporation to obtain the terpyridine primary amine organic corrosion inhibitor.

4. The method for preparing the terpyridine primary amine organic corrosion inhibitor according to claim 3, wherein the molar ratio of 4- (4-hydroxyphenyl) -2,2 ' -6 ', 2 ' -terpyridine, bromoalkylphthalimide and hydrazine hydrate is 1 (2-5): (1-3).

5. The preparation method of the terpyridine primary amine organic corrosion inhibitor as claimed in claim 3, wherein the specific reaction conditions of the substitution reaction in the step (1) are as follows: 4 ' (4-hydroxyphenyl) -2,2 ', 6 ' -terpyridine and anhydrous K are subjected to₂CO₃Dispersing in DMF or butanone, stirring for 25-35 min, adding bromoalkylphthalimide, and reacting at 80-90 deg.C for 20-30 h.

6. The preparation method of the terpyridine primary amine organic corrosion inhibitor as claimed in claim 4, wherein the K is anhydrous₂CO₃The amount ratio of DMF or butanone is 1g (50-70) mL.

7. The preparation method of the terpyridine primary amine organic corrosion inhibitor as claimed in claim 3, wherein the purification process of the reaction product in the step (1) is as follows: and cooling the reaction product to room temperature, filtering to remove insoluble substances, washing, drying, performing rotary evaporation, and sequentially performing column chromatography separation by using dichloromethane and dichloromethane/ethyl acetate as leacheate to obtain the intermediate product.

8. The method for preparing the terpyridine primary amine organic corrosion inhibitor as claimed in claim 3, wherein the alcohol in the step (1) is any one of methanol, ethanol, n-propanol and isopropanol.

9. The application of the terpyridine primary amine organic corrosion inhibitor in the marine anticorrosive paint as claimed in claim 1, wherein the addition amount of the terpyridine primary amine organic corrosion inhibitor for the marine anticorrosive paint accounts for 3-10% of the weight of the marine anticorrosive paint.

10. The application of the terpyridine primary amine organic corrosion inhibitor in the marine anticorrosive paint as claimed in claim 9, wherein the addition amount of the terpyridine primary amine organic corrosion inhibitor is 5% of the weight of the marine anticorrosive paint.

Background

The sea is a complex and harsh corrosive fouling environment, and the coating is the most direct, effective and economic corrosion prevention means for ships and marine engineering. At present, the common marine anticorrosive coatings are epoxy anticorrosive coatings, epoxy resin is taken as a film forming substance, and corrosion inhibitors (antirust pigments), shielding fillers, extender pigments, auxiliaries, solvents and the like are added to prepare the epoxy anticorrosive coatings.

However, under the harsh environment of high-temperature, high-humidity and high-salt 'three-high' seawater corrosion, the permeability of seawater is improved, and the inorganic corrosion inhibitor cannot corrode metal to generate Fe²⁺The rapid chelation and solidification is carried out to form a passivation film, a large amount of inorganic iron salt can be remained in the coating, the compatibility of the inorganic iron salt and the epoxy anticorrosive coating is poor, microcracks and gaps are easily generated on the surface and the inside of the coating under a harsh seawater corrosive environment, and after a large amount of seawater permeates into the coating, macroscopic phase separation such as bubbling, cracking, falling and the like can be rapidly carried out on the coating, so that the protection failure and corrosion are caused.

Disclosure of Invention

The invention aims to provide a terpyridyl primary amine organic corrosion inhibitor, a preparation method and application thereof, and terpyridyl and Fe of the terpyridyl primary amine organic corrosion inhibitor²⁺The coating has strong chelating coordination capacity, can play a role in high-efficiency corrosion inhibition when applied to a marine anticorrosive coating, effectively enhances the compactness of the marine anticorrosive coating, prevents corrosive media from permeating, and provides technical support for the development of long-life heavy-duty anticorrosive coatings.

The technical scheme adopted by the invention is as follows:

terpyridineThe primary amine organic corrosion inhibitor has a structural formula as follows:，

wherein R represents C₈-C₁₅Olefin or benzene aromatic hydrocarbon with benzene ring number not more than 3.

Further, R is (CH)₂)₈、(CH₂)₁₀、(CH₂)₁₂、(CH₂)₁₅、(CH₂)₄-C₆H₄-(CH₂)₄、(CH₂)₄-C₆H₄-CH₂-C₆H₄-(CH₂)₄Or (CH)₂)₄-C₆H₄-CH₂-C₆H₄-CH₂-C₆H₄- (CH₂)₄Any one of them.

A preparation method of a terpyridine primary amine organic corrosion inhibitor comprises the following steps:

(1) carrying out substitution reaction on 4 ' (4-hydroxyphenyl) -2,2 ', 2 ' -terpyridine and bromoalkyl phthalimide, and purifying a reaction product to obtain an intermediate product;

(2) and (3) adding hydrazine hydrate into the intermediate product by taking alcohol as a solvent to react for 2-3h at the temperature of 75-85 ℃, adding dichloromethane to filter insoluble substances, and removing dichloromethane by rotary evaporation to obtain the terpyridine primary amine organic corrosion inhibitor.

Further, the molar ratio of 4- (4-hydroxyphenyl) -2,2 ' -6 ', 2 ' -terpyridine, bromoalkylphthalimide, hydrazine hydrate is 1 (2-5): 1-3.

Further, the specific reaction conditions of the substitution reaction in step (1) are as follows: dispersing 4- (4-hydroxyphenyl) -2,2 ' -6 ', 2 ' -terpyridine and anhydrous K2CO3 in DMF or butanone, stirring for 25-35 min, adding bromoalkylphthalimide, and reacting at 80-90 deg.C for 20-30 h.

Further, anhydrous K₂CO₃With DMF or butanoneThe ratio is 1g (50-70) mL.

Further, the purification process of the reaction product in the step (1) is as follows: and cooling the reaction product to room temperature, filtering to remove insoluble substances, washing, drying, performing rotary evaporation, and sequentially performing column chromatography separation by using dichloromethane and dichloromethane/ethyl acetate as leacheate to obtain the intermediate product.

Further, the alcohol in the step (1) is any one of methanol, ethanol, n-propanol and isopropanol.

The application of the terpyridine primary amine organic corrosion inhibitor in the marine anticorrosive coating is characterized in that the addition amount of the terpyridine primary amine organic corrosion inhibitor for the marine anticorrosive coating accounts for 3-10% of the weight of the marine anticorrosive coating.

Furthermore, the addition amount of the terpyridyl primary amine organic corrosion inhibitor accounts for 5% of the weight of the marine anticorrosive coating.

The invention has the beneficial effects that:

1. the invention synthesizes a terpyridine primary amine organic corrosion inhibitor, the molecule of the organic corrosion inhibitor contains three pyridyl groups, when the organic corrosion inhibitor is applied to marine anticorrosive coatings, nitrogen atoms in the pyridyl groups can react with Fe²⁺Ions form a polydentate chelating ligand, and the coordination performance is stronger, so that the corrosion inhibition performance is greatly improved.

2. The terpyridine primary amine organic corrosion inhibitor disclosed by the invention contains primary amine groups in molecules, and when the terpyridine primary amine organic corrosion inhibitor is applied to an ocean anticorrosive coating, the primary amine groups can participate in the curing reaction of epoxy resin in the coating, so that the overall strength and compactness of the coating are improved, the penetration of a corrosive medium is prevented, the compactness of the ocean anticorrosive coating is effectively enhanced, the anticorrosive performance of the coating is further enhanced, and the service life of the anticorrosive coating is prolonged.

Drawings

FIG. 1 is a flow chart of the preparation of the terpyridine primary amine organic corrosion inhibitor.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following examples, wherein the raw materials and instruments used in the following examples are commercially available, and the data obtained in the examples of the present invention are average values of three or more repeated experiments unless otherwise specified. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The preparation flow chart of the terpyridine primary amine organic corrosion inhibitor is shown in figure 1. Example 1

(1) 3mmol of 4 '(4-hydroxyphenyl) -2, 2' 6 ', 2' -terpyridine and 0.42g of anhydrous K were added₂CO₃Dispersing in 20mL of DMF, stirring for 25 minutes at normal temperature, adding 6mmol of bromooctyl phthalimide, heating to 90 ℃ and reacting for 20 hours. After completion of the reaction, the reaction mixture was cooled to room temperature, and insoluble matter was removed by filtration. Removing solvent DMF by rotary evaporation to obtain crude product, dissolving the crude product in 20mL dichloromethane, washing with saturated NaCl and distilled water for 2-3 times, collecting organic phase, and washing with anhydrous MgSO₄The organic phase was dried and the solvent dichloromethane was removed by rotary evaporation, and then column chromatography was performed using dichloromethane, dichloromethane/ethyl acetate = 95/5 in this order as eluent to obtain an intermediate product.

(2) Dissolving the intermediate product in methanol, adding 3mmol of hydrazine hydrate, heating to 85 ℃, reacting for 2h, performing rotary evaporation to remove the methanol, adding 20mL of dichloromethane, filtering to remove insoluble substances, and performing rotary evaporation to remove the dichloromethane to obtain the organic corrosion inhibitor 4 ʹ - [4- (8-amino octyloxy) phenyl ] -2,2 ʹ:6 ʹ, 2' -terpyridine.

Adding the 4 ʹ - [4- (8-amino octyloxy) phenyl ] -2,2 ʹ:6 ʹ, 2' -terpyridine organic corrosion inhibitor into the marine anticorrosive paint in the weight ratio of 3%, 7% and 10% respectively to obtain the modified anticorrosive paint.

Example 2

(1) 3mmol of 4 '(4-hydroxyphenyl) -2, 2' 6 ', 2' -terpyridine and 0.42g of anhydrous K were added₂CO₃Dispersing in 25mL butanone, stirring for 30 minutes at normal temperature, adding 7.5mmol bromohelminthic alkyl phthalimide, heating to 85 ℃ and reacting for 24 hours. After completion of the reaction, the reaction mixture was cooled to room temperature, and insoluble matter was removed by filtration. Removing DMF by rotary evaporation to obtain crude product, and dissolving the crude productWashing with saturated NaCl and distilled water in 20mL dichloromethane for 2-3 times, collecting organic phase, and anhydrous MgSO₄The organic phase was dried and the solvent dichloromethane was removed by rotary evaporation, after which column chromatography was performed using dichloromethane, dichloromethane/ethyl acetate = 95/5 in sequence as eluent to give an intermediate product.

(2) Dissolving the intermediate product in n-propanol, adding 6mmol of hydrazine hydrate, heating to 80 ℃, reacting for 2.5h, performing rotary evaporation to remove the n-propanol, then adding 20mL of dichloromethane, filtering to remove insoluble substances, and performing rotary evaporation to remove the dichloromethane to obtain the organic corrosion inhibitor 4 ʹ - [4- (12-amino helminthoxy) phenyl ] -2,2 ʹ:6 ʹ, 2' -terpyridine.

The modified anticorrosive paint is obtained by adding the organic corrosion inhibitor of 4 ʹ - [4- (12-amino Helmholtoxy) phenyl ] -2,2 ʹ:6 ʹ, 2' -terpyridine into the marine anticorrosive paint in the weight ratio of 3%, 7% and 10%, respectively.

Example 3

(1) 3mmol of 4 '(4-hydroxyphenyl) -2, 2' 6 ', 2' -terpyridine and 0.42g of anhydrous K were added₂CO₃Dispersing in 30mL of DMF, stirring for 35 minutes at normal temperature, adding 15mmol of brominated p-xylylene phthalimide, heating to 80 ℃ and reacting for 30 hours. After completion of the reaction, the reaction mixture was cooled to room temperature, and insoluble matter was removed by filtration. Removing solvent DMF by rotary evaporation to obtain crude product, dissolving the crude product in 20mL dichloromethane, washing with saturated NaCl and distilled water for 2-3 times, collecting organic phase, and washing with anhydrous MgSO₄The organic phase was dried and the solvent dichloromethane was removed by rotary evaporation, after which column chromatography was performed using dichloromethane, dichloromethane/ethyl acetate = 95/5 in sequence as eluent to give an intermediate product.

(2) Dissolving the intermediate product in ethanol, adding 9mmol of hydrazine hydrate, heating to 75 ℃, reacting for 3h, performing rotary evaporation to remove ethanol, adding 20mL of dichloromethane, filtering to remove insoluble substances, and performing rotary evaporation to remove dichloromethane to obtain the organic corrosion inhibitor 4 ʹ - [4- (12-amino-p-phenylbutanyloxy) phenyl ] -2,2 ʹ:6 ʹ, 2' -terpyridine.

Adding the 4 ʹ - [4- (12-amino-p-phenylenedibutoxyl) phenyl ] -2,2 ʹ:6 ʹ, 2' -terpyridine organic corrosion inhibitor into the marine anticorrosive paint in the weight ratio of 3%, 7% and 10% respectively to obtain the modified anticorrosive paint.

Example 4

(1) 3mmol of 4 '(4-hydroxyphenyl) -2, 2' 6 ', 2' -terpyridine and 0.42g of anhydrous K were added₂CO₃Dispersing in 25mL butanone, stirring for 30 minutes at normal temperature, adding 7.5mmol bromo-p-phenylene-diphenylmethylene-dibutylen-phthalimide, heating to 85 ℃ and reacting for 24 hours. After completion of the reaction, the reaction mixture was cooled to room temperature, and insoluble matter was removed by filtration. Removing solvent DMF by rotary evaporation to obtain crude product, dissolving the crude product in 20mL dichloromethane, washing with saturated NaCl and distilled water for 2-3 times, collecting organic phase, and washing with anhydrous MgSO₄The organic phase was dried and the solvent dichloromethane was removed by rotary evaporation, after which column chromatography was performed using dichloromethane, dichloromethane/ethyl acetate = 95/5 in sequence as eluent to give an intermediate product.

(2) Dissolving the intermediate product in n-propanol, adding 6mmol of hydrazine hydrate, heating to 80 ℃, reacting for 2.5h, performing rotary evaporation to remove the n-propanol, then adding 20mL of dichloromethane, filtering to remove insoluble substances, and performing rotary evaporation to remove the dichloromethane to obtain the organic corrosion inhibitor 4 ʹ - [4- (17-aminobenzene dibutyloxy) phenyl ] -2,2 ʹ:6 ʹ, 2' -terpyridine.

Adding the 4 ʹ - [4- (17-aminodiphenylmethylene dibutyloxy) phenyl ] -2,2 ʹ:6 ʹ, 2' -terpyridine organic corrosion inhibitor into the marine anticorrosive paint in the weight ratio of 3%, 7% and 10% respectively to obtain the modified anticorrosive paint.

The terpyridine primary amine organic corrosion inhibitor of the four embodiments of the invention is added into the conventional marine anticorrosive coating to obtain the modified anticorrosive coating, and the hydraulic adhesion and the salt spray resistance of the anticorrosive coating on the surface of the carbon steel substrate are respectively tested, wherein the corrosion resistance of the anticorrosive coating is not added with the terpyridine primary amine organic corrosion inhibitor, and the test results are shown in table 1.

Table 1 test results of hydraulic adhesion and salt spray resistance of anticorrosive paint

According to the hydraulic adhesion and salt spray resistance test results, compared with an anticorrosive coating without the terpyridine primary amine organic corrosion inhibitor, the marine anticorrosive coating added with the terpyridine primary amine organic corrosion inhibitor has improved adhesion and salt spray resistance, has excellent performance when the addition amount is 5 percent, improves the adhesion by 40 to 100 percent and improves the salt spray resistance by 20 to 42.8 percent, and shows that the nitrogen atom of the terpyridine group and the metal atom of the base material form a stronger coordinate bond and the Fe permeated into the coating²⁺The organic chelate is generated quickly and efficiently, the diffusion and the spread of corrosion are effectively inhibited, and the salt spray resistance of the coating is obviously improved.

It should be noted that the above embodiments are only for illustrating the present invention, but the present invention is not limited to the above embodiments, and any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention fall within the protection scope of the present invention.