CN112694544A

CN112694544A - Glycan derivative and preparation method and application thereof

Info

Publication number: CN112694544A
Application number: CN202011506606.4A
Authority: CN
Inventors: 钟仁华; 刘娅莉; 罗小虎; 彭诗阳; 陈博; 潘心宇
Original assignee: Hunan Xinheng Environment Technology Co ltd
Current assignee: Hunan Xinheng Environment Technology Co ltd
Priority date: 2020-12-18
Filing date: 2020-12-18
Publication date: 2021-04-23
Anticipated expiration: 2040-12-18
Also published as: CN112694544B

Abstract

The invention relates to a glycan derivative and a preparation method and application thereof, wherein the glycan derivative has a structure shown as the following formula (I):

the polysaccharide derivative is connected with a five-membered ring containing N or S and a carbon-nitrogen double bond, can effectively prevent the metal surface from being corroded to generate flash rust, thereby preventing the metal from being corroded and generating hydrogen embrittlement, has high corrosion inhibition efficiency and low toxicity when used as a corrosion inhibitor, can be biologically degraded, can also increase the surface wetting effect of the coating,the leveling ability of the coating is improved, and the leveling property, appearance, adhesive force and service life of the coating are finally improved.

Description

Glycan derivative and preparation method and application thereof

Technical Field

The invention relates to the technical field of chemical new materials, in particular to anticorrosive materials and application thereof, and particularly relates to a glycan derivative and a preparation method and application thereof.

Background

With the global consumption of fresh water resources, the use of seawater as industrial cooling system water is a beneficial option to alleviate the shortage of fresh water resources. However, natural seawater contains a large amount of corrosive substances, such as chloride ions (Cl)^-) Sulfate ion (SO)₄ ^2-) Carbonate ion (CO)₃ ^2-) Organic acids, corrosive microorganisms, etc., which easily cause corrosion leakage in the cooling system, not only cause a significant decrease in heat exchange efficiency in the cooling system, but also cause rapid deterioration of equipment materials, thereby causing serious economic loss and safety problems. In the industrial production field, before the metal is treated by the treatment steps of phosphorization, oxidation, electrophoresis, coating, electroplating and the like, the metal is cleaned by an acid cleaning agent to remove slight rust and dirt on the surface of the metal. Usually, a certain amount of corrosion inhibitor is added into the pickling cleaner to protect the surface of the low-carbon steel from corrosion and hydrogen embrittlement during cleaning, wherein the hydrogen embrittlement is a phenomenon that hydrogen dissolved in steel is polymerized into hydrogen molecules to cause stress concentration and exceed the strength limit of the steel, and fine cracks are formed in the steel. At present, most inorganic or organic corrosion inhibitors have good applicability, but have the problems of high toxicity, environmental pollution, low corrosion inhibition efficiency and the like.

In addition, in the process of oil exploitation, oil well pipes are subjected to high-temperature and high-pressure environments with high chloride ions, high mineralization and high sulfur content, and the corrosion inhibitor is the most common method for preventing and treating corrosion of the oil well pipes. Similarly, the anti-flash rust agent is commonly used in the water-based paint, and the performance of the anti-flash rust agent directly affects the anti-corrosion function of the water-based paint and the cost of the paint.

Therefore, the development of the corrosion inhibitor which is environment-friendly, high in corrosion inhibition efficiency and low in toxicity in acidic and neutral environments is of great significance.

Disclosure of Invention

Based on the above, the invention provides the glycan derivative with high corrosion inhibition efficiency and low toxicity, and the preparation method and the application thereof.

One aspect of the present invention provides a glycan derivative having a structure represented by formula (I):

wherein L is selected from non-alkenyl with 2-10 carbon atoms or heteroalkane subunit with 1-10 carbon atoms;

R₁and R₂Each occurrence is independently selected from N or S;

10≤n₁≤100，n₁are integers.

In some of these embodiments, the heteroatom in the heteroalkane subunit is O.

In some embodiments, L is selected from either none or any of formulas (1) - (2):

wherein n is more than or equal to 1₂≤4，1≤n₃≤5，n₂、n₃Is an integer;

are attachment sites.

In some embodiments, the glycan derivative has a structure according to one of formulas (I-1) to (I-2):

wherein n is more than or equal to 1₂≤2，n₂To be integratedAnd (4) counting.

In some of these embodiments, n₂Is 1.

In some of these embodiments, R₁And R₂At least one is selected from N and at least one is selected from S for each occurrence.

In some of these embodiments, R₁At each occurrence, is selected from S; and/or

R₂At each occurrence, is selected from N.

Another aspect of the present invention also provides a method for preparing the above-described glycan derivative, comprising the steps of:

carrying out oxidation reaction on the compound 1 and an oxidant to obtain an intermediate M;

carrying out dehydration condensation reaction on the intermediate M and a compound 2 to obtain the glycan derivative;

wherein the structural formulas of the compound 1, the intermediate M and the compound 2 are as follows:

the invention also provides a corrosion inhibitor which comprises a corrosion inhibition auxiliary agent and any one of the polysaccharide derivatives.

The invention also provides a cleaning agent, which comprises a cleaning auxiliary agent and any one of the polysaccharide derivatives.

The invention also provides a coating, which is characterized by comprising a main resin and any one of the polysaccharide derivatives.

Furthermore, the invention also provides application of any one of the polysaccharide derivatives in preparation of preservative products.

Advantageous effects

1. The invention provides a glycan derivative shown as a formula (I), wherein a five-membered ring containing N or S and a carbon-nitrogen double bond are connected to a glycan molecule, the glycan derivative can effectively prevent a metal surface from being corroded to generate flash rust, so that the metal is prevented from being corroded and generating hydrogen embrittlement, when the glycan derivative is used as a corrosion inhibitor, the glycan derivative has high corrosion inhibition efficiency, low toxicity and biodegradability, can also increase the surface wetting effect of a coating, improves the leveling capability of the coating, and finally improves the leveling property, appearance, adhesive force and service life of the coating.

The polysaccharide derivative contains imidazole groups and carbon-nitrogen double bonds, and pi electrons in unsaturated bonds of the carbon-nitrogen double bonds are easy to form pi-d chemical bonds with the metal surface, so that the polysaccharide derivative can be stably adsorbed on the protected metal surface. On the other hand, hydrogen precipitated on the metal is easy to reduce carbon-nitrogen double bonds to obtain alkane, and then multi-molecular polysaccharide derivative polymers can be formed through polymerization, so that a polymer film is formed on the surface of the metal; meanwhile, the imidazole five-membered ring containing N or S can form a coordination bond with metal through an N or S atom to promote the adsorption of the imidazole five-membered ring on the surface of the metal, so that the metal is protected from corrosion. In addition, the glycan derivative can still effectively prevent carbon steel from being subjected to acid corrosion and hydrogen permeation under high-concentration hydrochloric acid and high temperature, and even a small amount of glycan derivative can still exert good corrosion inhibition performance, so that the requirements of running of an underground oil well pipe of oil drilling, an urban subway shield machine, metal pickling and the like on environmental protection, high efficiency and low consumption of a corrosion inhibitor are met, and the glycan derivative is biodegradable and environment-friendly.

2. In the preparation method of the glycan derivative, an intermediate M is obtained by carrying out oxidation reaction on a compound 1 and an oxidant; and (3) carrying out dehydration condensation reaction on the intermediate M and the compound 2 to obtain the glycan derivative. The preparation method has the advantages of simple and environment-friendly process, high product purity, no generation of toxic and harmful byproducts, and environmental protection.

Drawings

FIG. 1 is a chart of an infrared spectrum of a glycan derivative according to example 1 of the present invention;

FIG. 2 is an AC impedance profile of a glycan derivative of example 1 of the invention;

FIG. 3 is a Bode plot of a glycan derivative of example 1 of the invention;

FIG. 4 is a phase angle diagram of a glycan derivative of example 1 of the invention;

FIG. 5 is a graph showing the change in corrosion rate of low carbon steel in example 4 of the present invention;

FIG. 6 is a scanning electron micrograph of a water-based acrylic polyurethane coating film according to example 5 of the present invention.

Detailed Description

The compounds of the present invention, methods for their preparation and their use are described in further detail in the following examples. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Unless otherwise stated or contradicted, terms or phrases used herein have the following meanings:

the term "alkenylene" refers to a group remaining after an olefin has been removed from two hydrogen atoms and includes unsaturated hydrocarbons in which two hydrogens have been removed from the same carbon atom in the olefin and unsaturated hydrocarbons in which one hydrogen has been removed from each of different carbon atoms in the olefin. The phrase including the term, for example, alkenylene having 2 to 10 carbon atoms. Suitable examples include, but are not limited to: 1, 2-propinylidene (-C ═ CHCH)₂-), 1, 4-butynylene, (-CH)₂C＝CCH₂-) and the like.

Understandably, the term "heteroalkane subunit" refers to a group remaining after removing two hydrogen atoms from an alkane containing heteroatoms, such as oxygen, sulfur, nitrogen, etc., in the alkane, and the position and number of the heteroatoms are not particularly limited.

In the present invention, "-" denotes a connection site.

In the present invention, when the attachment site is not specified in the group, it means that an optional attachment site in the group is used as the attachment site;

the inventionWherein the single bond to which the substituent is attached extends through the corresponding ring, with the expression that the substituent may be attached to an optional position of the ring, e.g.

Wherein R is attached to any substitutable site of the phenyl ring.

The skilled person of the present invention finds: the glucomannan has the unique properties (shown in the specification) such as biodegradability, multifunction, nontoxicity, low production cost and the like, contains hydroxyl and epoxy groups in molecules, can interact with a metal surface and be adsorbed on the metal surface, and simultaneously, the hydroxyl and the epoxy groups in the molecular structure can also react with a carboxyl compound so as to further improve the anchoring capacity of the corrosion inhibitor on the metal surface.

The glucomannan has a structural formula.

However, further studies have shown that: in a corrosion experiment in simulated seawater only containing glucomannan, the corrosion inhibition efficiency of the glucomannan on low-carbon steel is found to be low, and the corrosion inhibition efficiency of the glucomannan on the low-carbon steel cannot meet the protection requirement of a metal surface.

In order to improve the corrosion inhibition efficiency of glucomannan, the technical personnel of the invention develop derivatives based on glucomannan through a large number of creative experiments, before the application, the technical personnel of the invention have explored the influence of connecting azo groups and propargyl alcohol groups on the hydroxyl positions of glucomannan molecules on improving the corrosion inhibition performance of the glucomannan, and apply for related patents. Further, on the basis of previous researches, the technical personnel of the invention carry out oxidative ring opening on hydroxyl of glucomannan molecules to form glycan with a linear molecular structure, and further adopt five-membered rings containing N or S and carbon-nitrogen double bond modification to improve the glycan with the linear molecular structure

One embodiment of the present invention provides a glycan derivative having a structure represented by formula (I):

R₁and R₂Each occurrence is independently selected from N or S;

10≤n₁≤100，n₁are integers.

It is understood that L is selected from the group consisting of where in formula (I) the nitrogen atom is directly attached to any optional attachment site in the five-membered ring.

The polysaccharide derivative contains imidazole groups and carbon-nitrogen double bonds, and pi electrons in unsaturated bonds of the carbon-nitrogen double bonds are easy to form pi-d chemical bonds with the metal surface, so that the polysaccharide derivative can be stably adsorbed on the protected metal surface. On the other hand, hydrogen precipitated on the metal is easy to reduce carbon-nitrogen double bonds to obtain alkane, and then multi-molecular polysaccharide derivative polymers can be formed through polymerization, so that a polymer film is formed on the surface of the metal; meanwhile, the five-membered ring containing N or S can form a coordinate bond with the metal through an N atom or an S atom to promote the adsorption of the five-membered ring on the surface of the metal, so that the metal is protected from corrosion. In addition, the glycan derivative can still effectively prevent carbon steel from being subjected to acid corrosion and hydrogen permeation under high-concentration hydrochloric acid and high temperature, and even a small amount of glycan derivative can still exert good corrosion inhibition performance, so that the requirements of environment protection, high efficiency and low consumption of corrosion inhibitors on underground oil well pipes of petroleum drilling, urban subway shield machine operation, metal pickling and the like are met.

When the polysaccharide derivative is used as a corrosion inhibitor, the corrosion inhibition efficiency is high, the toxicity is low, the polysaccharide derivative is biodegradable, the surface wetting effect of the coating can be improved, the leveling capability of the coating is improved, the leveling property, the appearance and the adhesive force of the coating are finally improved, and the service life of the coating is prolonged.

In some of these embodiments, the heteroatom in the heteroalkane subunit described above is O.

are attachment sites.

In some of these embodiments, 1 ≦ n₂≤2，1≤n₃≤3，n₂、n₃Are integers.

Further, the above L is selected from the group consisting of none or formula (1); further, n₂Is 1.

In some of these embodiments, the glycan derivative has a structure represented by one of formulae (I-1) to (I-2):

wherein n is more than or equal to 1₂≤2，n₂Are integers.

In some embodiments, the glycan derivative has a structure represented by one of formulae (I-3) to (I-4):

in some of the embodiments described herein, the first and second,

further, R₁And R₂At least one is selected from N and at least one is selected from S for each occurrence.

Further, R₁And R₂At least one R at each occurrence₂Selected from N, at least one R₁Is selected from S.

R₂At each occurrence, is selected from N.

In some embodiments, the glycan derivative is of formula (I-5):

in still another aspect, the present invention provides a method for preparing any one of the above-described glycan derivatives, comprising the following steps S100 to S200.

And step S100, carrying out oxidation reaction on the compound 1 and an oxidant to obtain an intermediate M.

In some embodiments, the oxidation reaction is performed under a protective gas atmosphere at a pH of 7.0; further, the conditions of the oxidation reaction are: reacting for 12-36 h at 60-120 ℃.

In some of these embodiments, the molar ratio of compound 1 to oxidant in step S100 is 1: (1.5-3.5).

In some of these embodiments, the oxidizing agent is selected from the group consisting of halide salts; further, the oxidizing agent is selected from sodium iodate.

In some embodiments, step S100 further comprises a step of purifying the product of the oxidation reaction by silica gel column chromatography to obtain a purified intermediate M after the oxidation reaction step; further, the purification steps are as follows: and removing the solvent from the mixed solution after the oxidation reaction to obtain a crude product, and purifying the crude product by silica gel column chromatography by using the mixed solution of methyl formate and diethyl ether as a eluent to obtain an intermediate M.

And step S200, carrying out dehydration condensation reaction on the intermediate M prepared in the step S100 and a compound 2 to obtain the glycan derivative.

the dehydration condensation reaction in step S200 is performed in a Dimethylsulfoxide (DMSO) solution system.

In some embodiments, the conditions of the dehydration condensation reaction are: reacting for 12-36 h at 60-120 ℃.

In some embodiments, in step S200, the esterification reaction conditions are: reacting for 10 to 15 hours at the temperature of between 80 and 120 ℃.

In some embodiments, in step S200, the molar ratio of intermediate M to compound 2 is 1 (1.5-2.5).

In some embodiments, step S200 further comprises a step of purifying the product of the dehydration condensation by silica gel column chromatography to obtain a purified polysaccharide derivative after the dehydration condensation reaction step; further, the purification steps are as follows: removing solvent from the mixture after dehydration condensation reaction to obtain crude product, and purifying the crude product by silica gel column chromatography with the mixture of diethyl ether and methyl formate as eluent to obtain polysaccharide derivative.

In the preparation method of the glycan derivative, the intermediate M is obtained by carrying out oxidation reaction on the compound 1 and an oxidant; and (3) carrying out ether and methyl formate reaction on the intermediate M and the compound 2 to obtain the polysaccharide derivative. The preparation method has the advantages of simple and environment-friendly process, high product purity, no generation of toxic and harmful byproducts, and environmental protection.

The invention also provides the application of any one of the glycan derivatives or the glycan derivative prepared by any one of the preparation methods in preparing a preservative product.

The glucomannan derivative has carbon-nitrogen double bonds and five-membered rings containing S or N, and the five-membered rings can generate interaction with metal, so that sugar derivative molecules can be adsorbed on the surface of the metal very favorably, and the corrosion inhibition efficiency of the glucomannan derivative can be improved; in addition, the polysaccharide derivative contains carbon-nitrogen double bonds, and five-membered rings containing S or N are easy to form coordinate bonds with metal atoms so as to enhance the adsorption force, so that the sugar derivative is easy to adsorb on the metal surface, thereby avoiding the corrosion of oxygen, water or other external impurities to the metal; hydrogen precipitated on the metal is easy to reduce carbon-nitrogen double bonds to obtain alkyl, so that a multi-molecular polysaccharide derivative polymer can be formed through polymerization, and a polymerization film is formed on the surface of the metal, so that the metal is protected from corrosion; can effectively prevent the corrosion and hydrogen permeation of carbon steel in acid under high-concentration hydrochloric acid and higher temperature, and can still exert good corrosion inhibition even a small amount of glucomannan derivative.

When the polysaccharide derivative is applied to preparation of a cleaning agent, the flash rust generated by corrosion of the metal surface can be avoided, so that the metal is prevented from being corroded and generating hydrogen embrittlement; when the polysaccharide derivative is applied to preparing the coating, the corrosion of water, oxygen or other external impurities to an interface in construction engineering can be avoided, and therefore the phenomenon of flash rust generation on a metal interface can be avoided.

Further, an embodiment of the present invention provides a corrosion inhibitor, which comprises a corrosion inhibition aid and the polysaccharide derivative of any one of the above or the polysaccharide derivative prepared by the above preparation method.

In some of these embodiments, the corrosion inhibiting additive is selected from quaternary ammonium salts.

The corrosion inhibitor has high corrosion inhibition efficiency, low toxicity, biodegradability and environmental protection.

The invention also provides a cleaning agent, which comprises a cleaning auxiliary agent and the glycan derivative or the glycan derivative prepared by the preparation method.

In one embodiment, the cleaner is a metal cleaner; further, the cleaning aid is selected from an acidic cleaning aid, an alkaline cleaning aid or a water-based cleaning aid.

Further, the cleaning aid is an acidic cleaning aid, such as hydrochloric acid.

The cleaning agent can effectively clean metal and protect the metal from corrosion.

The invention also provides a coating, which comprises a main resin and the glycan derivative or the glycan derivative prepared by the preparation method.

The coating can avoid the corrosion of water, oxygen or other external impurities to an interface in construction engineering, so that a metal interface can be prevented from generating a flash rust phenomenon, and the polysaccharide derivative can also increase the surface wetting effect of the coating, improve the leveling capability of the coating, finally improve the adhesive force of the coating and prolong the service life of the coating.

Further, the host resin may be selected from commonly used resins for preparing coatings, including but not limited to: epoxy resins, phenolic resins, polyester resins, polyurethane resins, acrylic resins, polycarbonate resins, and the like.

In some of these embodiments, the coating is a water-based coating.

While the present invention will be described with respect to particular embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but is intended to cover by the appended claims the scope of the invention, and that certain changes in the embodiments of the invention will be suggested to those skilled in the art and are intended to be covered by the appended claims.

Provided is a concrete embodiment.

Here, the polysaccharide derivatives according to the present invention, and the preparation methods and uses thereof are exemplified, but the present invention is not limited to the following examples.

Example 1

The synthetic route for the glycan derivative is shown below:

the specific synthetic process is as follows:

1) 5g of glucomannan (C) are weighed₂₄H₄₂O₂₁Molecular weight 60000-80000g/mol) GA was added to a 100mL round-bottomed flask, to which was added 10g of NaIO₄In combination with NH₃.H₂And adjusting the pH value of the reaction system to 7.0 by using the O solution, and then reacting for 24 hours at 60 ℃. And after the reaction is finished, centrifuging at the rotating speed of 2000rpm, filtering, washing for more than 3 times by using deionized water and absolute ethyl alcohol in sequence, and drying for 12 hours at 40 ℃ after the reaction is finished to obtain a pretreated GA product.

2) 40mg of the pretreated GA-1 product obtained in step 1) and 100mg of 4-aminothiazole were charged in a 40mL round-bottomed dimethyl sulfoxide (DMSO) flask while using NH3.H₂Adjusting the pH value of the reaction system to 7.0 by using O solution, magnetically stirring the mixture at 80 ℃ for reaction for 12 hours under the protection of nitrogen, removing the solvent after the reaction is finished, and using the mixtureMethyl formate/diethyl ether (volume ratio 3:1) was used as a eluent, and the crude product was purified by silica gel column chromatography to give intermediate GA-2 in 72% yield.

3) The target product GA-2 is subjected to infrared spectrum test, and the FT-IR spectrum is shown in figure 1. 3314cm-¹The absorption peak corresponds to the expansion vibration peak of C-OH; 1621cm^-1The absorption peak of (A) is a stretching vibration peak of C ═ N, and in addition 1615cm-¹The absorption peak is the stretching vibration peak of C-C and-C ═ C-in the five-membered ring, and 1300cm^-1～1110cm^-1The absorption peak in the range is the C-O stretching vibration peak.

Example 2

The corrosion resistance of the target product GA-2 of example 1 was measured as follows.

The raw material glucomannan GA, the intermediate product GA-1 and the target product GA-2 are respectively used as corrosion inhibitors, hydrochloric acid cleaning solutions containing the raw material GL, the intermediate product GA-1 and the target product GA-2 are correspondingly prepared, wherein the concentration of hydrochloric acid in the hydrochloric acid cleaning solutions is 0.5M, and the results of testing the zeta potential polarization curves (25 ℃) of low-carbon steel in the hydrochloric acid cleaning solutions containing different corrosion inhibitors are shown as follows.

1) FIG. 2 is an AC impedance spectrum of the glucomannan GA as the starting material, the intermediate GA-1 and the target GA-2 on a low carbon steel. The abscissa is the real part (Ω cm) of the impedance spectrum²) The ordinate is the imaginary part (omega cm) of the impedance spectrum²). The results show that the hydrochloric acid cleaning solution containing the target product GA-2 has the best anti-corrosion effect.

2) FIGS. 3 and 4 are Bode and Phase angle (Phase angle) graphs of the starting glucomannan GA, the intermediate GA-1 and the target GA-2 on mild steel, respectively. The abscissa in the Bode plot is frequency (Logf, Hz) and the ordinate is the magnification of the amplitude (Log | Z |); and the abscissa of the Phase angle (Phase angle) graph is frequency (Logf, Hz), and the ordinate is Phase angle (Phase angle, degree). Wherein, the concentration of hydrochloric acid in the hydrochloric acid cleaning agent is 0.5M, and when the concentration of GA-2 in the hydrochloric acid cleaning agent is 0, the solution is a Blank control solution and is marked as Blank solution.

As can be seen from the test results of FIGS. 3 and 4, the hydrochloric acid cleaning solution added with GA-2 can protect low-carbon steel from corrosion and has high corrosion inhibition efficiency.

3) Hydrochloric acid cleaning solution of target product GA-2 with different concentrations has corrosion inhibition efficiency (eta) on low-carbon steel at different temperatures_w) As shown in table 1.

Corrosion inhibition efficiency eta_w＝(C_R0-C_R1)/C_R0·100％

C_R0Corrosion rate of hydrochloric acid cleaning solution without corrosion inhibitor, C_R1Is the corrosion rate of the hydrochloric acid cleaning solution containing the target product GA-2 under certain temperature and certain concentration.

The larger the corrosion inhibition efficiency value is, the stronger the corrosion inhibition performance of the hydrochloric acid cleaning solution is.

TABLE 1

As can be seen from Table 1, the concentration of the target product GA-2 was 0.07mmol L at a temperature of 25 deg.C^-1The hydrochloric acid cleaning solution has the best corrosion inhibition.

Example 3

The hydrochloric acid cleaning solution containing the intermediate product GA-1 and the hydrochloric acid cleaning solution containing the target product GA-2 prepared in example 2 were examined for environmental friendliness, emulsion stability, and anti-soil redeposition, and the results are shown in table 2 below:

environmental protection property: (1) and (3) pH measurement: respectively preparing hydrochloric acid cleaning solution G, hydrochloric acid cleaning solution GA-1 and hydrochloric acid cleaning solution GA-2 by using a raw material glucomannan GA and an intermediate product GA-1 prepared in example 1 and a target product GA-2 as corrosion inhibitors, wherein the concentration of hydrochloric acid in the hydrochloric acid cleaning solution is 0.5M, and the concentrations of the raw materials GA, GA-1 and the target product GA-2 are 0.05 mmol/L; respectively taking 50ml of hydrochloric acid cleaning solution G, hydrochloric acid cleaning solution GA-1 and hydrochloric acid cleaning solution GA-2, respectively adding 100ml of deionized water, stirring for 15min under the condition of the rotation speed of 300r/min, respectively measuring the pH value of the solution by using a pH meter, and recording the pH value.

(2) And (3) phosphorus-containing substance determination: 50ml of the prepared hydrochloric acid cleaning solution G, hydrochloric acid cleaning solution GA-1 and hydrochloric acid cleaning solution GA-2 are respectively taken and added into a beaker, 1L of nitric acid solution is respectively added, the nitric acid solution is prepared by diluting 400ml of concentrated nitric acid (the mass fraction concentration of the concentrated nitric acid is 69%) to 1L with water, the mixture is slowly stirred for 15min, then 100G of molybdate is respectively added, and the color change of the solution is observed. The absence of color change indicates the absence of phosphorus, which is environmentally friendly.

Emulsion stability: mixing water and oil (stearic acid) according to a volume ratio of 1:9, respectively adding hydrochloric acid cleaning solution G, hydrochloric acid cleaning solution GA-1 and hydrochloric acid cleaning solution GA-2 which account for 1% of the total solution volume, uniformly stirring to obtain a mixed solution, transferring the mixed solution into a graduated centrifuge tube, centrifuging for 15min under the condition that the rotation speed is 4000rpm, recording the volume of an emulsified phase, and calculating the emulsion stability according to the percentage of the volume of the emulsified phase to the total solution volume.

Anti-soil redeposition: respectively taking 50ml of hydrochloric acid cleaning solution G, hydrochloric acid cleaning solution GA-1 and hydrochloric acid cleaning solution GA-2, respectively adding the hydrochloric acid cleaning solution G, the hydrochloric acid cleaning solution GA-1 and the hydrochloric acid cleaning solution GA-2 into 50ml of deionized water, and uniformly stirring to respectively prepare two solutions; and then respectively using the two solutions to clean the metal processed object which is stained with the oil stain, drying the metal processed object after the metal processed object is cleaned, and observing whether the oil stain exists on the surface of the metal processed object.

TABLE 2

Sample name	pH value	Phosphorus test	Emulsion stability	Anti-redeposition of soil
					Hydrochloric acid cleaning solution GA-2	0.92	No color change	93％	No greasy dirt on surface
Hydrochloric acid cleaning solution GA-1	1.01	No color change	87％	No greasy dirt on surface
					Hydrochloric acid cleaning solution GA	1.25	No color change	57％	Surface is greasy

Example 4

Taking glucomannan GA as a raw material as a corrosion inhibitor, preparing hydrochloric acid cleaning solution with different concentrations of GA, wherein the hydrochloric acid concentration is 0.5M and is marked as GA.

And preparing hydrochloric acid cleaning solution of GA-1 with different concentrations by taking the intermediate product GA-1 as a corrosion inhibitor, wherein the hydrochloric acid concentration is 0.5M and is marked as GA-1.

And (3) preparing hydrochloric acid cleaning solution of the target product GA-2 with different concentrations by taking the target product GA-2 as a corrosion inhibitor, wherein the hydrochloric acid concentration is 0.5M and is marked as GA-2.

The corrosion performance of the corrosion inhibitor can be evaluated by weight loss measurements of low carbon steel in a cleaning solution containing the corrosion inhibitor. The corrosion rate (C) of the corrosion inhibitor was calculated from the change in the weight of the low carbon steel before and after immersion according to the following formula_R，mg cm^-2h^-1)：

Wherein, the delta m, the s and the delta t are respectively the average weight loss (mg) of the low-carbon steel in the cleaning solution and the exposed area (cm) of the low-carbon steel^-2) And a dipping time (h).

In order to evaluate the weight loss of the low-carbon steel in the cleaning solution respectively containing the corrosion inhibitors GA, GA-1 and GA-2, five samples were measured in parallel under the same experimental condition in the weight loss measurement of all samples in the experiment to ensure the rigor and scientificity of the obtained data, and the average value was reported. The curve of the corrosion rate of the low-carbon steel after the low-carbon steel is immersed in the cleaning solution for 4 hours, which is along with the concentration of the corrosion inhibitor in the cleaning solution, is shown in fig. 5. The corrosion rate of the low-carbon steel can also reflect the corrosion inhibition rate of the corrosion inhibitor, and the smaller the numerical value is, the higher the corrosion inhibition rate of the corrosion inhibitor is, and the better corrosion inhibition performance is.

As can be seen from fig. 5, the corrosion rate of the low carbon steel initially gradually decreases with increasing concentration and then becomes stable. Low carbon steel containing 0.07mmol L of each^-1Minimum C in GA, GA-1 and GA-2 cleaning solution_RValues of about 0.673mg cm each^-2h^-1、0.0385mg cm^-2h^-1And 0.008mg cm^-2h^-1. As can be seen, the corrosion rate of the low carbon steel in the cleaning solution containing the target product GA-2 was significantly smaller than that of GA and GA-1.

Example 5

1) In a water-based blue two-component epoxy resin industrial coating with the trade name of ZF900, according to the components of hydroxyl acrylic resin: and (3) preparing a coating by using the polyisocyanate curing agent component with the weight ratio of 4.2:1, and preparing a coating film a by adopting an air spraying method.

2) Adding the target product GA-2 prepared in the embodiment 1 into the two-component water-based paint, wherein the adding amount is 0.052 percent by weight; then, the water-based acrylic polyurethane added with the target product GA-2 is prepared into a coating film b by adopting an air spraying method.

3) The adhesion of the coating film a and the coating film b is tested by referring to the standard paint film adhesion determination GB/T1720-. The results are shown in table 3 below.

TABLE 3

	Grade of adhesion
		Coating film a	2
Coating film b	1

According to the standard GB/T1720-1979, the adhesion force is measured by a circle drawing method and is divided into 7 grades, namely 1, 2, 3, 4, 5, 6 and 7, wherein the larger the number is, the poorer the adhesion force is.

4) The coating film a and the coating film b were observed under a scanning electron microscope, and the results are shown in FIG. 6. As can be seen in fig. 6: the paint film b (right panel) made of the water-based acrylic polyurethane modified with the addition of the target product GA-2 was smoother in surface than the paint film a (left panel) not modified with the addition of the target product GA-2.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A glycan derivative having a structure according to formula (I):

R₁and R₂Each occurrence is independently selected from N or S;

10≤n₁≤100，n₁are integers.

2. The glycan derivative of claim 1, wherein the heteroatom in the heteroalkane subunit is O.

3. The glycan derivative according to claim 1, wherein L is selected from none or any one of formulae (1) to (2):

are attachment sites.

4. The glycan derivative according to claim 1, wherein the glycan derivative has a structure represented by one of formulae (I-1) to (I-2):

wherein n is more than or equal to 1₂≤2，n₂Are integers.

5. The glycan derivative according to any one of claims 1 to 4, wherein R is₁And R₂At least one is selected from N and at least one is selected from S for each occurrence.

6. The method of producing a glycan derivative according to any one of claims 1 to 5, comprising the steps of:

7. a corrosion inhibitor comprising a corrosion inhibiting additive and a glycan derivative according to any one of claims 1 to 5.

8. A cleaning agent comprising a cleaning auxiliary and the polysaccharide derivative according to any one of claims 1 to 5.

9. A coating comprising a host resin and a glycan derivative according to any one of claims 1 to 5.

10. Use of a glycan derivative according to any one of claims 1 to 7 for the preparation of a preserved product.