CN112010990A

CN112010990A - Glucomannan derivative and preparation method and application thereof

Info

Publication number: CN112010990A
Application number: CN202010898118.6A
Authority: CN
Inventors: 周海军; 卓耀文; 刘娅莉; 罗小虎; 楚宗霖; 陈博; 朱日龙
Original assignee: Chem Yueyang Waterborne Additive Co ltd; Hunan University
Current assignee: Chem Yueyang Waterborne Additive Co ltd; Hunan University
Priority date: 2020-08-31
Filing date: 2020-08-31
Publication date: 2020-12-01
Anticipated expiration: 2040-08-31
Also published as: CN112010990B

Abstract

The invention relates to a glucomannan derivative and a preparation method and application thereof, wherein the glucomannan derivative has a structure shown as the following formula (I-1):

the glucomannan derivative contains alkynol structure as corrosion inhibitorThe corrosion inhibitor has excellent effect of reducing surface tension, can better wet the surface in an acid environment, has the characteristics of high corrosion inhibition efficiency, low toxicity, biodegradability and the like, can exert excellent corrosion inhibition performance even if a small amount of corrosion inhibitor is used, and can be used for preparing acid cleaning solution, underground acid corrosion inhibitor for petroleum drilling and the like and coating corrosion inhibition auxiliary agents.

Description

Glucomannan derivative and preparation method and application thereof

Technical Field

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

Background

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.

In summary, today with ever-increasing environmental protection requirements, there is an urgent need for corrosion inhibitors that are environmentally friendly, stable in acidic environments, have high corrosion inhibition efficiency, and have good wetting properties. However, most of the inorganic or organic corrosion inhibitors have disadvantages of high toxicity and high cost, and thus are difficult to be industrially applied on a large scale.

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 glucomannan derivative, the glucomannan derivative with high corrosion inhibition efficiency and low toxicity, and the preparation method and the application thereof are provided.

The invention provides a glucomannan derivative, which has a structure shown in a formula (I-1):

wherein L is selected from alkane subunits with 1-20 carbon atoms or heteroalkane subunits with 1-20 carbon atoms;

R₁、R₂、R₃and R₄Each independently selected from H, D, F, Cl, Br, alkyl with 1-30 carbon atoms, alkoxy with 1-30 carbon atoms, aromatic group with 5-40 ring atoms, heteroaromatic group with 5-40 ring atoms, or combination of the above systems;

10≤n₁≤100，n₁are integers.

In some of these embodiments, L is selected from any one of formulas (I-2) to (I-3):

wherein n is more than or equal to 1₂≤20，1≤n₃≤10，n₂、n₃Is an integer;

are attachment sites.

In some of these embodiments, the glucomannan derivative has a structure according to formula (I-4):

wherein n is more than or equal to 1₂≤10，n₂Are integers.

In some of these embodiments, R₁、R₂、R₃And R₄Each occurrence is independently selected from H, F, Cl, Br, alkyl with 1-10 carbon atoms, or alkoxy with 1-10 carbon atoms, or the combination of the systems.

In some of these embodiments, R₁、R₂、R₃And R₄Each occurrence is independently selected from H, F, Cl, Br, alkyl with 1-6 carbon atoms, alkoxy with 1-6 carbon atoms, or combination of these systems.

In some of these embodiments, R₁、R₂、R₃And R₄At each occurrence, is selected from H.

In some of these embodiments, the glucomannan derivative is represented by formula (I-5):

in another aspect, the present invention provides a method for preparing any one of the glucomannan derivatives described above, comprising the steps of:

carrying out esterification reaction on the compound 1 and the compound 2 to obtain an intermediate M;

carrying out esterification reaction on the intermediate M and a compound 3 to obtain a glucomannan derivative;

wherein the structural formulas of the compound 1, the compound 2, the compound 3 and the intermediate M are as follows:

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

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

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

Furthermore, the invention also provides application of any glucomannan derivative in preparation of preservative products.

Advantageous effects

1. The invention provides a glucomannan derivative shown as a structural formula (I-1), wherein a propargyl alcohol group is connected to a glucomannan molecule, and the glucomannan derivative prevents the metal surface from being corroded to generate flash rust, so that the metal is prevented from being corroded and generating hydrogen embrittlement phenomenon, and when the glucomannan derivative is used as a corrosion inhibitor, the corrosion inhibitor has high corrosion inhibition efficiency, low toxicity, biodegradability and environmental protection.

On one hand, the glucomannan derivative contains an alkynol esterified structure, pi electrons in unsaturated triple bonds of alkynyl are easy to form pi-d chemical bonds with the surface of metal, so that the glucomannan derivative can be stably adsorbed on the surface of the protected metal; meanwhile, due to the existence of the alkynol ester structure, the glucomannan derivative can play a good role in reducing surface tension, so that the glucomannan derivative can better wet the surface in an acidic environment, a metal base material in the acidic environment can be protected from hydrogen embrittlement corrosion caused by hydrogen released by a corrosion cathode, and the corrosion inhibition efficiency of the glucomannan derivative as a corrosion inhibitor is improved. On the other hand, the hydrogen precipitated on the metal easily reduces the alkynol to give an enol, and further, a multi-molecular glucomannan derivative polymer is formed by polymerization, and a polymer film is formed on the metal surface, thereby protecting the metal from corrosion. In addition, the glucomannan derivative can still effectively prevent carbon steel from being subjected to acid corrosion and hydrogen permeation under high-concentration hydrochloric acid and higher temperature, and even a small amount of the glucomannan derivative can still exert good corrosion inhibition, so that the requirements of environment protection, high efficiency and low consumption of corrosion inhibitors on the operation of underground oil well pipes of petroleum drilling, urban subway shield machines, metal pickling and the like are met.

2. In the preparation method of the glucomannan derivative, an intermediate M is obtained by carrying out esterification reaction on a compound 1 and a compound 2; and carrying out esterification reaction on the intermediate M and the compound 3 to obtain the glucomannan 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.

3. The invention provides a corrosion inhibitor, which comprises the glucomannan derivative or the glucomannan derivative prepared by the preparation method. The corrosion inhibitor has high corrosion inhibition efficiency, low toxicity and biodegradability.

4. The present invention provides a cleaning agent comprising the glucomannan derivative or the glucomannan derivative prepared by the above preparation method. The cleaning agent can effectively clean metal and protect the metal from corrosion.

5. The invention provides a coating, which comprises the glucomannan derivative or the glucomannan derivative prepared by the preparation method. The coating can avoid the corrosion of water, oxygen or other external impurities to an interface in the construction process, so that the flash rust phenomenon of a metal interface can be avoided, and the glucomannan derivative can also increase the surface wetting effect of the coating, improve the leveling capability of the coating, finally improve the decoration property, the adhesive force and the service life of the coating.

Drawings

FIG. 1 is a nuclear magnetic carbon spectrum of glucomannan derivative according to example 1 of the invention;

FIG. 2 is an infrared spectrum of a glucomannan derivative of example 1 of the invention;

FIG. 3 is a Nyquist plot of glucomannan derivative of example 1 of the invention;

FIG. 4 is a Bode plot of glucomannan derivative of example 1 according to the invention;

FIG. 5 is a phase angle spectrum of glucomannan derivative according to example 1 of the invention;

FIG. 6 is a graph showing the change of the corrosion inhibition rate of glucomannan derivative according to example 1 of the present invention;

FIG. 7 is a scanning electron micrograph of a water-based acrylic polyurethane coating film according to example 4 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 "alkylidene" refers to a group remaining after an alkane has been removed from two hydrogen atoms, and includes saturated hydrocarbons in which two hydrogens have been removed from the same carbon atom in an alkane and saturated hydrocarbons in which one hydrogen has been removed from each of different carbon atoms in an alkane. Phrases encompassing this term, for example, alkane subunits having 1 to 20 carbon atoms. Suitable examples include, but are not limited to: methylene, ethylene (-CH)₂CH₂-), 1, 2-propylene (-CH)₂CH₂CH₂-), 1, 4-butylene, (-CH)₂CH₂CH₂CH₂-) and the like.

Understandably, the term "heteroalkane subunit" means that a heteroatom such as oxygen, sulfur, nitrogen, etc., is contained in any one of the above-mentioned alkane subunits, and the position and number of the heteroatom are not particularly limited.

The term "aryl" refers to an aromatic hydrocarbon group derived by removing one hydrogen atom from the aromatic ring compound and may be a monocyclic aryl group, or a fused ring aryl group, or a polycyclic aryl group, at least one of which is an aromatic ring system for polycyclic ring species. The number of ring atoms in the aryl group having 5 to 40 ring atoms is the number of ring-forming atoms, and for example, the number of ring atoms in benzene is 6 and the number of ring atoms in biphenyl is 12. Suitable examples include, but are not limited to: benzene, biphenyl, naphthalene, anthracene, phenanthrene, perylene, triphenylene, and derivatives thereof.

It will be appreciated that a plurality of aryl groups may also be interrupted by short non-aromatic units (e.g. < 10% of non-H atoms, such as C, N or O atoms), such as in particular acenaphthene, fluorene, or 9, 9-diarylfluorene, triarylamine, diarylether systems should also be included in the definition of aryl groups.

Natural plant extracts, natural polymers, amino acids and other natural high molecular polymers generally have groups containing hybrid atoms such as N, O, and the groups can be used as adsorption active points and adsorbed to the surface of metal to protect the metal from corrosion; and its excellent intrinsic characteristics, such as biodegradability, good stability and having multiple adsorption centers, have received extensive attention from researchers. For example, it is reported that chitosan can be used as an environment-friendly corrosion inhibitor for low-carbon steel and copper, and natural polymers such as glucose and hydroxypropyl cellulose have a good corrosion inhibition effect on low-carbon steel in an acidic corrosion medium; however, the corrosion inhibition efficiency of the organic corrosion inhibitors can not meet the requirements of actual industrial production at present.

The technical personnel of the invention have found that: the glucomannan has a polysaccharide structure, and particularly has certain unique properties such as biodegradability, multifunctionality, nontoxicity, low production cost and the like, and the glucomannan contains hydroxyl and epoxy groups in molecules, can interact with a metal surface and be adsorbed on the metal surface, and meanwhile, the hydroxyl and the epoxy groups in the molecular structure can also react with a carboxyl compound, so that the anchoring capacity of the corrosion inhibitor on the metal surface is further improved.

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 the glucomannan, the technicians of the invention develop the derivatives based on the glucomannan through a large number of creative experiments. Before the technical scheme of the invention is obtained, the technical personnel of the invention explore the influence of the azo group connected on the glucomannan molecule on improving the glucomannan; in order to further expand the application of glucomannan molecules, the technical personnel of the invention further explore deeply and develop a salinization treatment method of glucomannan so as to improve the solubility of the glucomannan in water and enhance the corrosion inhibition effect of the glucomannan on metals; the inventive proposal is that the glucomannan molecule is connected with the propiolic alcohol group, which can improve the corrosion inhibition efficiency and further increase the surface wetting effect of the coating, thereby improving the leveling ability of the coating, further improving the adhesive force of the coating and prolonging the service life.

One embodiment of the present invention provides a glucomannan derivative having a structure represented by formula (I-1):

R₁、R₂、R₃and R₄Each independently selected from H, D, F, Cl, Br, alkyl with 1-30 carbon atoms, alkoxy with 1-30 carbon atoms, aromatic group with 5-40 ring atoms, or heteroaromatic group with 5-40 ring atomsA perfume group, or a combination of these systems;

n1 is more than or equal to 10 and less than or equal to 100, and n1 is an integer.

The glucomannan derivative with the structure shown in the formula (I-1) is characterized in that an alkynol group is connected to a glucomannan molecule, the glucomannan derivative prevents the metal surface from being corroded to generate flash rust, so that the metal is prevented from being corroded and generating hydrogen embrittlement phenomenon, and when the glucomannan derivative is used as a corrosion inhibitor, the corrosion inhibition efficiency is high, the toxicity is low, and the glucomannan derivative is biodegradable.

The glucomannan derivative has a large amount of hydroxyl groups, and the interaction between the hydroxyl groups and the metal is also beneficial to the adsorption of molecules on the surface of the metal, so that the corrosion inhibition efficiency of the glucomannan derivative can be improved; the glucomannan derivative contains an alkynol structure, the alkynol can easily form a coordinate bond with a metal atom, the adsorption force is enhanced, and the glucomannan derivative is very easily adsorbed on the surface of the metal, so that the corrosion of oxygen, water or other external impurities to the metal is avoided; the hydrogen separated out from the metal is easy to reduce the alkynol, and the glucomannan derivative can be polymerized to form a multi-molecular polymer film through secondary chemical action after being adsorbed, so that the metal is protected from being corroded; the glucomannan derivative containing the alkynol structure has stable performance, keeps better corrosion inhibition even at lower concentration, and can effectively corrode carbon steel in acid and permeate hydrogen at high-concentration hydrochloric acid and higher temperature.

In some of these embodiments, L is selected from the group consisting of heteroalkane subunits having 1 to 20 carbon atoms; further, the heteroatom in the heteroalkane subunit is selected from at least one of O, N and S, and further, the heteroatom is selected from O.

In some embodiments, L is selected from any one of (I-2) to (I-3):

are attachment sites.

In some of these embodiments, 1 ≦ n₂≤10，1≤n₃≤5，n₂、n₃Are integers.

Further, L is selected from the group consisting of formula (I-3), n₂Is 2.

In some embodiments, the glucomannan derivative has a structure represented by formula (I-4):

wherein n is more than or equal to 1₂≤10，n₂Are integers.

Further, R₁、R₂、R₃And R₄Each occurrence is independently selected from H, F, Cl, Br, alkyl of 1-6 carbon atoms, or alkoxy of 1-6 carbon atoms, or combinations thereof.

Further, R₁、R₂、R₃And R₄Each occurrence is independently selected from H, F, Cl, Br, alkyl with 1-2 carbon atoms, or a combination of these systems.

Further, R₁、R₂、R₃And R₄At each occurrence, is selected from H.

In some embodiments, the glucomannan derivative is represented by formula (I-5):

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

And step S100, carrying out esterification reaction on the compound 1 and the compound 2 to obtain an intermediate M.

In some embodiments, the esterification reaction is carried out under the action of concentrated sulfuric acid and sulfurous acid chloride in a protective gas atmosphere; further, the esterification reaction conditions are: reacting for 10 to 15 hours at the temperature of between 80 and 120 ℃.

In some of these embodiments, the molar ratio of compound 1 to compound 2 in step S100 is 1: (1-1.5).

In some embodiments, step S100 further comprises a step of purifying the esterification reaction product by silica gel column chromatography to obtain a purified intermediate M after the esterification reaction step; further, the purification steps are as follows: the solvent was removed from the mixture after the esterification reaction to obtain a crude product, which was purified by silica gel column chromatography using cyclohexane and ethyl acetate as a eluent to obtain an intermediate M.

And (4) carrying out esterification reaction on the intermediate M prepared in the step (S100) and the compound 3 to obtain the glucomannan derivative.

in the preparation method of the glucomannan derivative, an intermediate M is obtained by carrying out esterification reaction on the compound 1 and the compound 2; and carrying out esterification reaction on the intermediate M and the compound 3 to obtain the glucomannan derivative P. 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.

In some of these examples, the esterification reaction in step S200 is carried out under the action of DCC/DMAP.

DCC is N, N' -dicyclohexylcarbodiimide, DMAP is dimethylaminopyridine, carboxyl in the intermediate M can be activated, the reaction rate is accelerated, and byproducts generated in the process of reaction staying in the intermediate can be avoided, so that the efficiency of the esterification reaction is improved.

In some embodiments, in step S200, the molar ratio of intermediate M, compound 3, N-Dicyclohexylcarbodiimide (DCC), and 4-Dimethylaminopyridine (DMAP) is 1 (1-3): 1-2.

Specifically, in step S200, the molar ratio of intermediate M, compound 3, N-Dicyclohexylcarbodiimide (DCC), and 4-Dimethylaminopyridine (DMAP) is 1:1.6:1: 1.

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, the step S200 further comprises a step of purifying the esterified product by silica gel column chromatography to obtain a purified glucomannan derivative; further, the purification steps are as follows: removing solvent from the mixture after esterification reaction to obtain crude product, and purifying the crude product by silica gel column chromatography with cyclohexane and ethyl acetate as eluent to obtain glucomannan derivative.

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

The glucomannan derivative has a large number of hydroxyl groups, and the interaction between the hydroxyl groups and the metal is beneficial to the adsorption of molecules on the surface of the metal, so that the corrosion inhibition efficiency of the glucomannan derivative can be improved; the glucomannan derivative contains an alkynol structure, a coordinate bond is easily formed between an alkynol molecule and a metal atom, the adsorption force is enhanced, and the glucomannan derivative is easily adsorbed on the surface of the metal, so that the corrosion of oxygen, water or other external impurities to the metal is avoided; the hydrogen separated out from the metal is easy to reduce alkynol to obtain enol, so that a multi-molecular glucomannan 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 glucomannan derivative is applied to preparing a cleaning agent, the metal surface can be prevented from being corroded to generate flash rust, so that the metal is prevented from being corroded and generating hydrogen embrittlement; when the glucomannan derivative is applied to preparing the coating, the corrosion of water, oxygen or other external impurities to the interface in the construction engineering can be avoided, and the flash rust phenomenon of the metal interface can be avoided.

Further, an embodiment of the present invention provides a corrosion inhibitor, which comprises a corrosion inhibition aid and the glucomannan derivative of any one of the above or the glucomannan 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 glucomannan derivative or the glucomannan 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 glucomannan derivative or the glucomannan 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 glucomannan derivative can also increase the surface wetting effect of the coating, improve the leveling capacity 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.

The glucomannan derivatives according to the invention and their preparation and use are exemplified here, but the invention is not limited to the examples described below.

Example 1

The route of the glucomannan derivative synthesis is shown in the following figure:

the specific synthetic process is as follows:

1) 5g of glucomannan (C) are weighed₂₄H₄₂O₂₁Molecular weight 60000-₂CO₃And 10g NaOH in 100mL of aqueous solution, at 60 ℃ for 24 h. After the reaction is finished, centrifuging and filtering at the rotating speed of 2000rpm, then 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 GL product.

2) 20mg of the pretreated GL product obtained in step 1), 40mL of succinic acid and 50mL of concentrated sulfuric acid were added to a round-bottomed flask containing 80mL of dimethyl sulfoxide (DMSO), and the mixture was magnetically stirred at 90 ℃ under nitrogen protection for 12 hours, after the reaction was completed, the solvent was removed, and the crude product was purified by silica gel column chromatography using cyclohexane/ethyl acetate (volume ratio 3:1) as a eluent to obtain intermediate M in a yield of 68%.

3) Adding the intermediate product M prepared in the step 2), butynediol, N-Dicyclohexylcarbodiimide (DCC) and 4-Dimethylaminopyridine (DMAP) into a round-bottom flask filled with Dichloromethane (DCM) according to a molar ratio of 1:1.6:1:1, and then carrying out magnetic stirring reaction at 90 ℃ for 12 hours under the protection of nitrogen. After the reaction is finished, the solvent is removed by vacuum filtration to obtain a crude product. The crude product was purified by silica gel column chromatography using cyclohexane/ethyl acetate (volume ratio 3:1) as eluent. Finally, the desired product P was obtained in white, 65% yield.

4) And carrying out structural test on the target product P. The specific results are as follows:

the nuclear magnetic carbon spectrum of the target product P is shown in figure 1. In FIG. 1, chemical shifts at 113.46ppm, 36.25ppm and 31.5ppm are C, respectively₉，C₇And C₈Chemical shift of (1), the chemical shift at 60ppm to 80ppm corresponds to C₁～C₆Chemical shift of (d).

5) The target product P is subjected to infrared spectrum test, and the FT-IR spectrum thereof is shown in figure 2. 3304cm in FIG. 2^-1、2908cm^-1、1758cm^-1The absorption peaks at the position (A) correspond to the stretching vibration peaks of C ≡ O in CO-H, C ≡ C and-COOH respectively; 1656cm^-1The absorption peak of (A) is a stretching vibration peak of-C ═ O-, and further 1615cm^-1The absorption peak is the stretching vibration peak of C ═ C/C-C and-C ═ C-in turn, and 1300cm^-1～1110cm^-1The absorption peak in the range is the C-O stretching vibration peak.

Example 2

The target product P of example 1 was subjected to the corrosion resistance test, specifically as follows.

The raw material glucomannan GL, the intermediate product M and the target product P are respectively used as corrosion inhibitors, and hydrochloric acid cleaning solution containing the raw material GL, the intermediate product M and the target product P is correspondingly prepared, wherein the concentration of hydrochloric acid in the hydrochloric acid cleaning solution is 0.5M, and the potentiodynamic polarization curve (25 ℃) of low-carbon steel in the hydrochloric acid cleaning solution containing different corrosion inhibitors is tested, and the results are shown as follows.

1) FIG. 3 shows the starting material glucomannan GL,and (3) an alternating current impedance spectrogram of the intermediate product M and the target product P on 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 result shows that the hydrochloric acid cleaning solution containing the target product P has the best anti-corrosion effect.

2) Fig. 4 and 5 are Bode and Phase angle diagrams of the starting glucomannan GL, the intermediate product M and the target product P 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 P 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 fig. 4 and 5, the hydrochloric acid cleaning solution added with P can protect low-carbon steel from corrosion and has high corrosion inhibition efficiency.

3) The hydrochloric acid cleaning solution of the target product P 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_Rc(P)]/C_R0

C_R0Corrosion rate of hydrochloric acid cleaning solution containing no P, C_Rc(P)Is the corrosion rate of the hydrochloric acid cleaning solution containing the target product P 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 P was 0.038mm at a temperature of 25 ℃olL^-1The hydrochloric acid cleaning solution has the best corrosion inhibition.

Example 3

The environmental protection property, emulsion stability and anti-soil redeposition property of the cleaning agent P prepared in example 1 and the glucomannan GP as the raw material were measured, and the results are shown in table 2 below:

environmental protection property: (1) and (3) pH measurement: respectively preparing hydrochloric acid cleaning liquid G and hydrochloric acid cleaning liquid P by using raw material glucomannan GL and the target product P prepared in the example 1 as corrosion inhibitors, wherein the concentration of hydrochloric acid in the hydrochloric acid cleaning liquid is 0.5M, and the concentration of the raw material GL and the target product P is 0.038 mmol/L; respectively adding 50ml of hydrochloric acid cleaning solution 1 and hydrochloric acid cleaning solution 2 into 100ml of deionized water, stirring for 15min at the rotating 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 prepared hydrochloric acid cleaning solution G and hydrochloric acid cleaning solution P are respectively 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.

Emulsion stability: water and oil (stearic acid) were mixed as 1: 9, respectively adding hydrochloric acid cleaning solution G and hydrochloric acid cleaning solution P 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 by 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 and hydrochloric acid cleaning solution P, respectively adding the hydrochloric acid cleaning solution G and the hydrochloric acid cleaning solution P 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

	pH value	Phosphorus content	Emulsion stability	Anti-redeposition of soil
					Hydrochloric acid cleaning solution P	0.67	No color change	90％	No greasy dirt on surface
Hydrochloric acid cleaning solution G	1.1	No color change	63％	Surface is greasy

Example 4

1) In the WUL800 waterborne blue two-component acrylic polyurethane industrial coating, the coating comprises the following components in percentage by weight: and (3) preparing a coating by using the polyisocyanate curing agent component with the weight ratio of 3.5:1, and preparing a coating film a by adopting an air spraying method.

2) Adding the target product P prepared in the embodiment 1 into the two-component water-based paint, wherein the adding amount is 0.045% by weight; then, the water-based acrylic polyurethane added with the target product P 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. 7. As can be seen in fig. 7: the surface of a paint film b (right picture) prepared by adding the target product P modified waterborne acrylic polyurethane is smoother than that of a paint film a (left picture) without adding the target product P, because the alkynol structure in the product P can improve the dispersion property of the polyisocyanate curing agent, thereby promoting the curing of the waterborne coating, and also playing a role in eliminating foaming and promoting the smoother surface.

Example 5

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

The raw material diacetylene alcohol is used as a corrosion inhibitor, hydrochloric acid cleaning solution with different concentrations of diacetylene alcohol is prepared, and the hydrochloric acid concentration is 0.5M and is marked as By.

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

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).

And (3) evaluating the weight loss of the low-carbon steel in the cleaning solution respectively containing the corrosion inhibitors GL, By and P, and in order to ensure the rigor and scientificity of the obtained data in the experiment, in the weight loss measurement of all samples, parallelly measuring five samples under the same experiment condition and reporting the average value. 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. 6.

As can be seen from fig. 6, the corrosion rate of the low carbon steel initially gradually decreases with increasing concentration and then becomes stable. The low-carbon steel contained 0.038mmol L of each^-1Of GL, butynediol and P, minimum C in the wash liquor_RValues were about 0.495mg cm, respectively^-2h^-1、0.281mg cm^-2h^-1And 0.112mg cm^-2h^-1. Therefore, the corrosion inhibition rate of the target product P is obviously superior to that of GL and butynediol.

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 glucomannan derivative having a structure according to formula (I-1):

10≤n₁≤100，n₁are integers.

2. The glucomannan derivative of claim 1, wherein L is selected from any one of formulas (I-2) to (I-3):

are attachment sites.

3. The glucomannan derivative of claim 1, wherein the glucomannan derivative has a structure according to formula (I-4):

wherein n is more than or equal to 1₂≤10，n₂Are integers.

4. The glucomannan derivative of claim 1, wherein R is₁、R₂、R₃And R₄Each occurrence is independently selected from H, F, Cl, Br, alkyl with 1-10 carbon atoms, or alkoxy with 1-10 carbon atoms, or the combination of the systems.

5. The glucomannan derivative of claim 4, wherein R is₁、R₂、R₃And R₄Each occurrence is independently selected from H, F, Cl, Br, alkyl with 1-6 carbon atoms, alkoxy with 1-6 carbon atoms, or combination of the systems.

6. The glucomannan derivative of claim 1, wherein R is₁、R₂、R₃And R₄At each occurrence, is selected from H.

7. The glucomannan derivative of claim 1, wherein the glucomannan derivative is according to formula (I-5):

8. the process for the preparation of glucomannan derivative according to any one of claims 1 to 7, comprising the steps of:

9. a corrosion inhibitor, characterized in that it comprises a corrosion inhibiting auxiliary and a glucomannan derivative according to any one of claims 1 to 7.

10. A cleaning agent comprising a cleaning auxiliary and the glucomannan derivative according to any one of claims 1-7.

11. A coating comprising a host resin and a glucomannan derivative according to any one of claims 1-7.

12. Use of the glucomannan derivative according to any one of claims 1-7 for the preparation of preserved products.