A multi-functional modified alkanolamine

Abstract

The present invention discloses a multi-functional modified alkanolamine, which solves the technical problems that the adsorption capacity and complexing capacity of alkanolamine in the prior art are weak, and the grinding aid and strength enhancing effects are poor. It comprises the following steps: S1: adding alkanolamine and acrylic acid into a reaction vessel, adding a catalyst and an inhibitor, carrying out an esterification reaction at a reaction temperature of 140°C to 180°C for 6 to 10 hours to obtain a crude product of alkanolamine acrylate; S2: purifying the alkanolamine acrylate by rectification; S3: adding diethanolamine into the purified alkanolamine acrylate, adding sodium ethoxide as a catalyst, placing the reaction vessel in a stirrer for stirring, and carrying out the reaction at room temperature for 4 to 6 hours; S4: separating and removing sodium ethoxide after the reaction to obtain the multi-functional modified alkanolamine. The present invention can have a stronger dispersion effect on cement powder during cement grinding, so the grinding aid effect is better.

Description

Technical Field

[0001] The present invention belongs to the technical field of cement production, and particularly relates to a modified alkanolamine with multiple functional groups. Background Art

[0002] Triethanolamine is a common polyhydroxy tertiary amine. As a common raw material for cement grinding aids, adding it during grinding can improve the cement grinding efficiency and at the same time increase the cement strength; Triisopropanolamine is also a common polyhydroxy tertiary amine, which has a better grinding aid effect than triethanolamine. It has no obvious improvement on the early strength of cement, but has an obvious improvement on the later strength; Diethanolmonoisopropanolamine is the alkanolamine most used in the current cement grinding aid industry. Its grinding aid effect is close to that of triisopropanolamine. In terms of strength enhancement effect, its early strength is close to that of triethanolamine, and its later strength is slightly lower than that of triisopropanolamine. It can be said to combine the characteristics of triethanolamine and triisopropanolamine.

[0003] The above-mentioned several common alkanolamines have been widely used for nearly a decade. Domestic grinding aid manufacturers all use grinding aids produced from these alkanolamines, and their performance is seriously homogenized, lacking further development.

[0004] The present invention is a modified alkanolamine with multiple functional groups. On the basis of existing alkanolamines, acrylic acid is used to esterify with the existing several alkanolamines, and then an addition reaction is carried out with diethanolamine to synthesize a modified alkanolamine with multiple functional groups. More functional groups are grafted, so that the number of hydroxyl groups on the same plane increases from the original 3 to 4, improving the adsorption capacity and complexing ability of the alkanolamine, and optimizing the grinding aid and strength enhancement effects. Summary of the Invention

[0005] The purpose of the present invention is to provide a modified alkanolamine with multiple functional groups to solve the technical problems of weak adsorption capacity and complexing ability of alkanolamines in the prior art and poor grinding aid and strength enhancement effects.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] A modified alkanolamine with multiple functional groups provided by the present invention, its preparation includes the following steps:

[0008] S1: Add alkanolamine and acrylic acid to the reaction vessel, add a catalyst and an inhibitor, and carry out an esterification reaction at a reaction temperature of 140 °C to 180 °C for 6 to 10 hours to obtain a crude product of alkanolamine acrylate;

[0009] S2: Purify the alkanolamine acrylate by rectification;

[0010] S3: Add diethanolamine to the purified alkanolamine acrylate, add sodium ethoxide as a catalyst, place the reaction vessel in a stirrer for stirring, and carry out the reaction at room temperature for 4 to 6 hours;

[0011] S4: After the reaction is completed, sodium ethoxide is separated and removed to obtain a multi-functional group modified alkanolamine.

[0012] Furthermore, in the step S1, the alkanolamine is one or more of triethanolamine and triisopropanolamine.

[0013] Furthermore, in the step S1, the molar ratio of the alkanolamine to acrylic acid is 1 - 1.5:1.

[0014] Furthermore, in the step S1, the catalyst is concentrated sulfuric acid or p-toluenesulfonic acid, and the inhibitor is hydroquinone.

[0015] Furthermore, in the step S3, the molar ratio of alkanolamine acrylate to diethanolamine is 1:1.

[0016] Based on the above technical solutions, the embodiments of the present invention can at least produce the following technical effects:

[0017] The multi-functional group modified alkanolamine provided by the present invention has more hydroxyl groups on the same plane compared with the existing alkanolamines. For traditional alkanolamines such as triethanolamine, diethanolmonoisopropanolamine, and triisopropanolamine, the number of hydroxyl groups on the same plane is only 3, while the number of hydroxyl groups of the multi-functional group modified alkanolamine of the present invention is 4. It can have a stronger dispersing effect on cement powder during cement grinding, so the grinding aid effect is better. At the same time, the more hydroxyl groups make the accelerating effect of the modified alkanolamine on cement more obvious and the strength enhancing effect better. Specific Embodiments

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement it. When the combination of technical solutions appears to be contradictory or unable to be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0019] The object of the present invention is achieved by the following technical solutions:

[0020] Example 1:

[0021] S1: Add triethanolamine and acrylic acid into the reaction vessel. The ratio of triethanolamine to acrylic acid is 1.5:1. Add a catalyst and an inhibitor. The catalyst accounts for 2% of the total amount of reactants. p-Toluenesulfonic acid is selected as the catalyst. The inhibitor accounts for 3% of the total amount of reactants. Hydroquinone is selected as the inhibitor. Conduct an esterification reaction at a reaction temperature of 160 °C for 6 hours to obtain crude triethanolamine acrylate;

[0022] S2: Purify triethanolamine acrylate by distillation;

[0023] S3: Add diethanolamine to the purified triethanolamine acrylate. The ratio of triethanolamine acrylate to diethanolamine is 1:1. Add sodium ethoxide as the catalyst. The addition amount of sodium ethoxide is 5% of the total amount of reactants. Place the reaction vessel in a stirrer and stir. Conduct the reaction at room temperature for 6 hours;

[0024] S4: After the reaction is completed, remove sodium ethoxide to obtain multi-functional group modified triethanolamine.

[0025] Conduct a small grinding test on P.O42.5 cement with 30% multi-functional group modified triethanolamine aqueous solution and 30% triethanolamine. The dosage is 5 / 10,000;

[0026] The mix proportion of P.O42.5 cement is 78% clinker, 4% desulfurized gypsum, 5% limestone, 2% fly ash, 6% refined furnace bottom slag, and 5% black stone.

[0027] The grinding time is the same. The experimental data are shown in Table 1 below:

[0028] Table 1 Experimental data of small grinding of P.O42.5 cement

[0029]

[0030] Example 2:

[0031] S1: Add triisopropanolamine and acrylic acid into the reaction vessel. The ratio of triisopropanolamine to acrylic acid is 1:1. Add a catalyst and an inhibitor. The catalyst accounts for 3% of the total amount of reactants. Concentrated sulfuric acid is selected as the catalyst. The inhibitor accounts for 5% of the total amount of reactants. Hydroquinone is selected as the inhibitor. Conduct an esterification reaction at a reaction temperature of 140 °C for 8 hours to obtain crude triisopropanolamine acrylate;

[0032] S2: Purify triisopropanolamine acrylate by distillation;

[0033] S3: Add diethanolamine to the purified triisopropanolamine acrylate. The ratio of triisopropanolamine acrylate to diethanolamine is 1:1. Add sodium ethoxide as a catalyst, and the addition amount of sodium ethoxide is 5% of the total amount of reactants. Place the reaction vessel in a stirrer and stir. React at room temperature for 6 hours;

[0034] S4: After the reaction is completed, remove sodium ethoxide to obtain multi-functional group modified triisopropanolamine.

[0035] Conduct a small grinding test on P.O42.5 cement with 30% multi-functional group modified triisopropanolamine aqueous solution and 30% triisopropanolamine aqueous solution, and the dosage is 5 / 10,000:

[0036] The mix proportion of P.O42.5 cement is 81% clinker, 3% desulfurized gypsum, 6% limestone, 4% bottom slag, and 6% volcanic ash.

[0037] The grinding time is the same, and the experimental data are shown in Table 2 below:

[0038] Table 2 Experimental data of small grinding of P.O42.5 cement

[0039]

[0040]

[0041] Example 3:

[0042] S1: Add diethanolmonoisopropanolamine and acrylic acid to the reaction vessel. The ratio of diethanolmonoisopropanolamine to acrylic acid is 1.2:1. Add a catalyst and an inhibitor. The catalyst is 3% of the total amount of reactants. Select p-toluenesulfonic acid as the catalyst, and the inhibitor is 4% of the total amount of reactants. Select hydroquinone as the inhibitor. Conduct an esterification reaction at a reaction temperature of 150 °C for 10 hours to obtain crude diethanolmonoisopropanolamine acrylate;

[0043] S2: Purify diethanolmonoisopropanolamine acrylate by rectification;

[0044] S3: Add diethanolamine to the purified diethanolmonoisopropanolamine acrylate. The ratio of diethanolmonoisopropanolamine acrylate to diethanolamine is 1:1. Add sodium ethoxide as a catalyst, and the addition amount of sodium ethoxide is 5% of the total amount of reactants. Place the reaction vessel in a stirrer and stir. React at room temperature for 6 hours;

[0045] S4: After the reaction is completed, remove sodium ethoxide to obtain multi-functional group modified diethanolmonoisopropanolamine.

[0046] Conduct a small-scale grinding test on M32.5 cement by mixing 35% aqueous solution of multi-functional modified diethanol monoisopropanolamine with 35% aqueous solution of triisopropanolamine, with the dosage being 5 / 10,000:

[0047] The mix proportion of M32.5 cement is 53% clinker, 3% desulfurized gypsum, 20% limestone, 8% coal combustion slag, 6% pyrite slag, 3% fly ash, and 7% manganese slag.

[0048] The grinding time is the same, and the experimental data are shown in Table 3 below:

[0049] Table 3 Experimental data of small-scale grinding test on M32.5 cement

[0050]

[0051]

[0052] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. Application of a multi-functional modified alkanolamine in a cement grinding aid, characterized in that, the preparation of the multi-functional modified alkanolamine comprises the following steps: S1: Add alkanolamine and acrylic acid into a reaction vessel, add a catalyst and an inhibitor, and carry out an esterification reaction at a reaction temperature of 140°C to 180 °C for 6 to 10 hours to obtain a crude product of alkanolamine acrylate; the alkanolamine is one or more of triethanolamine, triisopropanolamine, and diethanolmonoisopropanolamine; S2: Purify the alkanolamine acrylate by distillation; S3: Add diethanolamine to the purified alkanolamine acrylate, add sodium ethoxide as a catalyst, place the reaction vessel in a stirrer and stir, and carry out the reaction at room temperature for 4 to 6 hours; S4: After the reaction is completed, separate and remove sodium ethoxide to obtain a multi-functional modified alkanolamine; in the step S1, the ratio of the alkanolamine to acrylic acid is a molar ratio of 1 to 1.5:1 In the step S1, the catalyst is concentrated sulfuric acid or p-toluenesulfonic acid, and the inhibitor is hydroquinone; In the step S3, the molar ratio of alkanolamine acrylate to diethanolamine is 1:1.

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