阅读说明：本技术 一种高效烷氧基化咪唑啉衍生物阻锈剂及制备方法及应用 (Efficient alkoxylated imidazoline derivative rust inhibitor and preparation method and application thereof ) 是由 杨振声 杨健 张晓娟 贾长英 邹明旭 王永杰 于 2021-01-22 设计创作，主要内容包括：本发明公开了一种高效烷氧基化咪唑啉衍生物阻锈剂的应用,使用时,将基准水泥、标准砂、水和阻锈剂按比例混合并搅拌均匀,振实至返浆,再插入钢筋,阻锈剂分子通过扩散吸附到钢筋表面,起到阻锈作用。烷氧基链段的引入使得分子具有聚羧酸减水剂单体的结构,能最大程度的实现阻锈剂分子与混凝土的配伍性,不会对混凝土的物理化学性能造成严重影响,不仅可以增加分子的空间位阻,阻挡氯离子的浸入,还能起到分散混凝土的作用、防止混凝土坍落度损失而不引起明显缓凝的,可以很大程度上提高钢筋在侵蚀环境中的使用寿命。(The invention discloses an application of an efficient alkoxylated imidazoline derivative rust inhibitor. The introduction of the alkoxy chain segment enables the molecule to have the structure of a polycarboxylate superplasticizer monomer, the compatibility of the rust inhibitor molecule and concrete can be realized to the greatest extent, the physical and chemical properties of the concrete cannot be seriously affected, the steric hindrance of the molecule can be increased, the invasion of chloride ions is blocked, the effect of dispersing the concrete can be achieved, the concrete slump loss is prevented, obvious delayed coagulation is not caused, and the service life of the steel bar in an erosion environment can be prolonged to a great extent.)

1. A high-efficiency alkoxylated imidazoline derivative rust inhibitor is characterized in that: the chemical structural formula of the rust inhibitor is shown as the following formula

Wherein R is C16-C20 hydrocarbyl, n is 0-8, and m is 40-70.

2. The highly effective alkoxylated imidazoline derivative rust inhibitor of claim 1, wherein: n is 0 or 1, and m is 45-55.

3. A method of making the highly effective alkoxylated imidazoline derivative rust inhibitor of claim 1, wherein: comprises the following steps

(1) Mixing fatty acid containing 16 to 20 carbon atoms with hydroxyethyl ethylenediamine, adding the mixture into a reaction kettle, adding dimethylbenzene serving as a water carrying agent, dehydrating and stirring the mixture at a certain temperature for reaction, and removing the dimethylbenzene under reduced pressure after the reaction is finished to obtain an imidazoline derivative intermediate;

(2) and (3) putting a certain amount of imidazoline derivative intermediate into an autoclave, adding a certain amount of propylene oxide and a certain amount of ethylene oxide under a high-pressure condition and at a certain temperature, and aging to obtain a final product.

4. The process for the preparation of alkoxylated imidazoline derivatives according to claim 3, wherein: the fatty acid is one of hexadecadienoic acid, oleic acid or linoleic acid, linolenic acid, octadecadienoic acid, eicosatrienoic acid or eicosapentaenoic acid.

5. The process for the preparation of alkoxylated imidazoline derivatives according to claim 3, wherein the fatty acid and hydroxyethylethylenediamine are present in a molar ratio of 1: 1.05-1.1, wherein the addition amount of the dimethylbenzene is 30-50 percent of the total mass of the fatty acid and the hydroxyethyl ethylenediamine, and the dimethylbenzene is firstly dehydrated by reaction at 180 ℃ under 160 ℃ and then dehydrated by reaction at 230 ℃ under 210 ℃.

6. The use of the highly effective alkoxylated imidazoline derivative rust inhibitor of claim 1, wherein: when the rust inhibitor is used, the reference cement, the standard sand, the water and the rust inhibitor are mixed in proportion and uniformly stirred, the mixture is compacted until slurry returns, then the steel bar is inserted, and molecules of the rust inhibitor are adsorbed on the surface of the steel bar through diffusion to play a rust inhibiting role.

7. The use of a highly effective alkoxylated imidazoline derivative rust inhibitor according to claim 6, wherein: the addition amount of the rust inhibitor is 0.3-1.5% of the mass of the concrete.

Technical Field

The invention relates to the technical field of rust inhibitors, in particular to a preparation method of an efficient alkoxylated imidazoline derivative rust inhibitor and application of the efficient alkoxylated imidazoline derivative rust inhibitor in reinforced concrete.

Background

The reinforced concrete is a building material widely used in modern society, is used for building structures in various industries, and plays a great role in national economic construction. However, the reinforced concrete structure is often deteriorated by cracking, corrosion of the reinforcing steel bars, and the like after a short period of use due to the increase in environmental pollution, and the like. The early failure of reinforced concrete structures caused by the corrosion of steel bars is a prominent disaster worldwide nowadays. Therefore, the prevention of the corrosion of the steel bars becomes a key point from the source, wherein the use of the steel bar rust inhibitor is the most convenient and effective method with good economical efficiency.

Many compounds have been or are still used as corrosion inhibitors for reinforced concrete, such as inorganic corrosion inhibitors like sodium nitrite, sodium benzoate, potassium dichromate, stannous chloride, sodium silicate, ammonia, sodium phosphate, etc., and organic corrosion inhibitors like quaternary ammonium salts, sodium glycerophosphate, hydroxy phosphate, ethylmaleimide, dimethylethanolamine, xanthylamine, ammonium carbamate, hydrazine, ethylenediamine, dicyclohexylamine, etc. These corrosion inhibitors are classified into an oxide film type, a precipitate film type, and an adsorption film type according to the type of the protective film. Some oxide film type rust inhibitors such as potassium dichromate can reduce the compressive strength of concrete more (20-40%), while stannous chloride has shorter action time, and although sodium nitrite and calcium nitrite which are commonly used have little influence on the strength of concrete and better rust inhibition effect, the sodium nitrite and the calcium nitrite have the rust inhibition effect only when the sodium nitrite and the calcium nitrite are used in a large amount, and nitrite has toxicity and certain damage to the environment and health, and is forbidden to be used in some countries. The deposited film type rust inhibitor such as sodium glycerophosphate and hydroxy phosphate is often weaker in binding force with metal and porous and loose in texture, so that the rust inhibiting effect is weaker than that of an oxidized film layer. The nitrogen-containing amine compounds belong to adsorption film type rust inhibitors, contain unpaired lone pair electrons, have certain electron donating capability, can form coordinate bonds with empty d orbitals of iron atoms to generate chemical adsorption, and have better protective effect.

Meanwhile, the rust inhibitor is used as an additive of concrete, and does not have adverse effect on the physical and chemical processes of cement hydration when in use. Therefore, the test of the changes of the cement setting time, the compression strength, the breaking strength and other properties after the rust inhibitor is added is also an important index for evaluating whether the rust inhibitor can be really practical. Therefore, the molecules of the rust inhibitor need to introduce a substituent to enhance the compatibility of the molecules and concrete, so that the rust inhibitor can be dispersed in the concrete without precipitation and is not easy to be leached out by water. Therefore, the development of the high-efficiency rust inhibitor which has the advantages of functionality and good compatibility and is suitable for other concrete admixtures has more practicability.

Disclosure of Invention

The invention aims to provide a high-efficiency alkoxylated imidazoline derivative rust inhibitor which is a functional organic matter consisting of three parts, namely long-chain alkyl, imidazoline ring and alkoxy chain segments, wherein the double-layer protection of the long-chain alkyl and the imidazoline ring can effectively avoid the damage of chloride ions and the like to a passivation film on the surface of a steel bar, and the high-efficiency alkoxylated imidazoline derivative rust inhibitor is a novel organic molecule which is environment-friendly, strong in thermal stability, difficult to volatilize and strong in dispersibility.

In order to achieve the purpose, the invention provides the following technical scheme: a high-efficiency alkoxylated imidazoline derivative rust inhibitor has a chemical structural formula shown as the following formula

Wherein R is C16-C20 hydrocarbyl, n is 0-8, and m is 40-70.

The invention also provides the following technical scheme: a preparation method of a high-efficiency alkoxylated imidazoline derivative rust inhibitor comprises the following steps:

(1) mixing fatty acid containing 16 to 20 carbon atoms with hydroxyethyl ethylenediamine, adding the mixture into a reaction kettle, adding dimethylbenzene serving as a water carrying agent, dehydrating and stirring the mixture at a certain temperature for reaction, and removing the dimethylbenzene under reduced pressure after the reaction is finished to obtain an imidazoline derivative intermediate;

(2) and (3) putting a certain amount of imidazoline derivative intermediate into an autoclave, adding a certain amount of propylene oxide and a certain amount of ethylene oxide under a high-pressure condition and at a certain temperature, and aging to obtain a final product.

The invention also provides the following technical scheme: the application of the high-efficiency alkoxylated imidazoline derivative rust inhibitor comprises the following steps: when the rust inhibitor is used, the reference cement, the standard sand, the water and the rust inhibitor are mixed in proportion and uniformly stirred, the mixture is compacted until slurry returns, then the steel bar is inserted, and molecules of the rust inhibitor are adsorbed on the surface of the steel bar through diffusion to play a rust inhibiting role.

Compared with the prior art, the invention has the beneficial effects that: the introduction of the alkoxy chain segment enables the molecule to have the structure of a polycarboxylate superplasticizer monomer, the compatibility of the rust inhibitor molecule and concrete can be realized to the greatest extent, the physical and chemical properties of the concrete cannot be seriously affected, the steric hindrance of the molecule can be increased, the invasion of chloride ions is blocked, the effect of dispersing the concrete can be achieved, the concrete slump loss is prevented, obvious delayed coagulation is not caused, and the service life of the steel bar in an erosion environment can be prolonged to a great extent.

Detailed Description

The invention provides a technical scheme that: a high-efficiency alkoxylated imidazoline derivative rust inhibitor has a chemical structural formula shown as the following formula

Wherein R is C16-C20 hydrocarbyl, n is 0-8, and m is 40-70. Preferably, n is 0 or 1 and m is 45 to 55. The addition of the propoxylated molecule (i.e. n) can reduce the molecular viscosity and contractility, increase the fluidity of the molecule, and determine whether to add according to different requirements and practical application conditions. The number of the ethoxylated molecules (i.e. m) can ensure the solubility of the molecules in water, and is similar to that of the ethoxylated molecules in the common polycarboxylic acid water reducing agent macromonomer in the market, so that the addition of the ethoxylated molecules can not cause great influence on the physical and chemical properties of concrete.

The invention also provides a preparation method of the high-efficiency alkoxylated imidazoline derivative rust inhibitor, which comprises the following steps

(1) Mixing fatty acid containing 16 to 20 carbon atoms with hydroxyethyl ethylenediamine, adding the mixture into a reaction kettle, adding dimethylbenzene serving as a water carrying agent, dehydrating and stirring the mixture at a certain temperature for reaction, and removing the dimethylbenzene under reduced pressure after the reaction is finished to obtain an imidazoline derivative intermediate;

(2) and (3) putting a certain amount of imidazoline derivative intermediate into an autoclave, adding a certain amount of propylene oxide and a certain amount of ethylene oxide under a high-pressure condition and at a certain temperature, and aging to obtain a final product.

The fatty acid is one of hexadecadienoic acid, oleic acid or linoleic acid, linolenic acid, octadecadienoic acid, eicosatrienoic acid or eicosapentaenoic acid. The molar ratio of the fatty acid to the hydroxyethyl ethylenediamine is 1: 1.05-1.1, the addition of dimethylbenzene is 30-50% of the total mass of fatty acid and hydroxyethyl ethylenediamine, and the reaction is firstly carried out at 180 ℃ for dehydration and then at 230 ℃ for dehydration at 210 ℃.

The invention also provides application of the high-efficiency alkoxylated imidazoline derivative rust inhibitor, when the high-efficiency alkoxylated imidazoline derivative rust inhibitor is used, the reference cement, the standard sand, the water and the rust inhibitor are mixed and stirred uniformly in proportion, the mixture is compacted until slurry returns, then a steel bar is inserted, and molecules of the rust inhibitor are adsorbed to the surface of the steel bar through diffusion to play a rust inhibiting role. The addition amount of the rust inhibitor is 0.3-1.5% of the mass of the concrete.

Example 1

(1) Mixing 0.5mol of oleic acid and 0.525mol of hydroxyethyl ethylenediamine, adding 75g of dimethylbenzene, reacting and dehydrating at the temperature of 160 ℃ and 180 ℃ until the water yield is 0.45-0.5mol of water, heating to the temperature of 210 ℃ and 230 ℃ for reacting and dehydrating until the water yield is 0.45-0.5mol of water, and decompressing and removing the dimethylbenzene after the reaction is finished.

(2) And (3) putting 0.5mol of imidazoline derivative intermediate into an autoclave, adding 0.5mol of propylene oxide, adding 25mol of ethylene oxide, and aging to obtain a final product.

(3) Prepared full Ca (OH) containing 1.15% NaCl₂Pouring the solution into three glass ground bottles, adding 0.3% of the rust inhibitor, putting a reinforcing steel bar test bar, completely immersing the bar into the solution, and tightly covering the bottle caps. The natural potential of the steel bars at 1d, 3d, 5d and 7d was measured by a voltmeter and compared with the blank.

Example 2

(1) Mixing 0.5mol of linoleic acid and 0.54mol of hydroxyethyl ethylenediamine, adding 82g of dimethylbenzene, reacting and dehydrating at the temperature of 160 ℃ and 180 ℃ until the water yield is 0.45-0.5mol of water, then heating to the temperature of 210 ℃ and 230 ℃ for reacting and dehydrating until the water yield is 0.45-0.5mol of water, and decompressing and removing the dimethylbenzene after the reaction is finished.

(2) And (3) taking 0.5mol of imidazoline derivative intermediate into an autoclave, adding 1mol of propylene oxide, adding 30mol of ethylene oxide, and aging to obtain a final product.

(3) Prepared full Ca (OH) containing 1.15% NaCl₂Pouring the solution into three glass ground bottles, adding 0.6% of the rust inhibitor, putting a reinforcing steel bar test bar, completely immersing the bar into the solution, and tightly covering the bottle caps. The natural potential of the steel bars at 1d, 3d, 5d and 7d was measured by a voltmeter and compared with the blank.

Example 3

(1) Mixing 0.5mol of linoleic acid and 0.55mol of hydroxyethyl ethylenediamine, adding 86g of dimethylbenzene, reacting and dehydrating at the temperature of 160 ℃ and 180 ℃ until the water yield is 0.45-0.5mol of water, heating to the temperature of 210 ℃ and 230 ℃ for reacting and dehydrating until the water yield is 0.45-0.5mol of water, and decompressing and removing the dimethylbenzene after the reaction is finished.

(2) And (3) taking 0.5mol of imidazoline derivative intermediate into an autoclave, adding 1.5mol of propylene oxide, adding 35mol of ethylene oxide, and aging to obtain a final product.

(3) Prepared full Ca (OH) containing 1.15% NaCl₂Pouring the solution into three glass ground bottles, adding 1% of the rust inhibitor, putting a reinforcing steel bar test bar, completely immersing the bar into the solution, and tightly covering the bottle caps. The natural potential of the steel bars at 1d, 3d, 5d and 7d was measured by a voltmeter and compared with the blank.

Example 4

(1) Mixing 0.5mol of linoleic acid and 0.53mol of hydroxyethyl ethylenediamine, adding 80g of dimethylbenzene, reacting and dehydrating at the temperature of 160 ℃ and 180 ℃ until the water yield is 0.45-0.5mol of water, then heating to the temperature of 210 ℃ and 230 ℃ for reacting and dehydrating until the water yield is 0.45-0.5mol of water, and decompressing and removing the dimethylbenzene after the reaction is finished.

(2) And (3) taking 0.5mol of imidazoline derivative intermediate into an autoclave, adding 28mol of ethylene oxide, and aging to obtain a final product.

(3) Prepared full Ca (OH) containing 1.15% NaCl₂Pouring the solution into three glass ground bottles, adding 1.5% of the rust inhibitor, putting a reinforcing steel bar test bar, completely immersing the bar into the solution, and tightly covering the bottle caps. The natural potential of the steel bars at 1d, 3d, 5d and 7d was measured by a voltmeter and compared with the blank.

Example 1 test results

Time	Blank/mv	Adding rust inhibitor/mv
			1d	-228	-160
3d	-240	-166
			5d	-256	-183
7d	-262	-183

Example 2 test results

Time	Blank/mv	Adding rust inhibitor/mv
			1d	-228	-140
3d	-240	-152
			5d	-256	-161
7d	-262	-162

Example 3 test results

Time	Blank/mv	Adding rust inhibitor/mv
			1d	-228	-126
3d	-240	-135
			5d	-256	-143
7d	-262	-143

Example 4 test results

Time	Blank/mv	Adding rust inhibitor/mv
			1d	-228	-105
3d	-240	-120
			5d	-256	-128
7d	-262	-129