阅读说明：本技术 一种混凝土防冻剂的制备方法 (Preparation method of concrete antifreezing agent ) 是由 沈丽萍 于 2021-01-12 设计创作，主要内容包括：本发明属于混凝土添加剂技术领域,具体涉及一种混凝土防冻剂的制备方法。本发明以聚乙烯醇、聚丙烯酰胺作为基础原料,通过利用辅助剂作用,起到很好的分散作用,随后再与海藻酸钠、壳聚糖进行混合,通过在酸性条件下,利用甲醛作用,并且利用戊二醛的交联剂的作用,进行反应,形成了多孔隙海绵状的凝胶结构状,并且尿素、甲醛进行反应,形成了脲醛树脂,对其进行包裹,增加分散性,可以很好的分散在混凝土的内部,同时由于聚丙烯酰胺,同时可以很好对冰晶的形成进行干扰,使冰晶发生变异,使其不能产生冰,起到很好的防冻效果。(The invention belongs to the technical field of concrete additives, and particularly relates to a preparation method of a concrete antifreezing agent. The invention takes polyvinyl alcohol and polyacrylamide as basic raw materials, plays a good role in dispersion by utilizing the action of an auxiliary agent, then is mixed with sodium alginate and chitosan, reacts by utilizing the action of formaldehyde and the action of a cross-linking agent of glutaraldehyde under an acidic condition to form a porous spongy gel structure, and reacts with urea and formaldehyde to form urea-formaldehyde resin which is wrapped to increase the dispersion and can be well dispersed in the concrete.)

1. The preparation method of the concrete antifreezing agent is characterized by comprising the following steps:

(1) putting the mixture, water and an auxiliary agent into a reactor according to the mass ratio of 7: 12-16: 1-3, uniformly stirring, adding a mixture A accounting for 20-30% of the mass of the mixture, protecting with nitrogen, adjusting the pH to 3-4, adding formaldehyde accounting for 25-40% of the mass of the mixture, heating, and preserving heat;

(2) after the heat preservation is finished, adding glutaraldehyde accounting for 13-16% of the mass of the mixture, uniformly stirring, preserving heat, cooling, discharging, freeze-drying, and collecting a dried substance;

(3) taking 160-180 parts of water, 50-55 parts of mixed monomer, 25-30 parts of urea, 15-20 parts of dry matter, 6-9 parts of ammonium chloride, 6-13 parts of polyacrylamide and 1-4 parts of surfactant according to parts by weight, putting the water, the mixed monomer, the dry matter and the surfactant into a reaction kettle, and uniformly stirring;

(4) after uniformly stirring, adding urea and ammonium chloride, adjusting pH, protecting with nitrogen, heating, stirring for reaction, cooling, adding polyacrylamide, stirring, standing, discharging, freeze-drying, and collecting freeze-dried product to obtain the concrete antifreezing agent.

2. The preparation method of the concrete antifreezing agent according to claim 1, wherein the mixture in the step (1) is prepared by mixing polyvinyl alcohol and polyacrylamide according to a mass ratio of 9: 2-4.

3. The method for preparing the concrete antifreezer according to claim 1, wherein the auxiliary agent in the step (1) is any one of sodium dodecyl benzene sulfonate and sodium dodecyl sulfate.

4. The preparation method of the concrete antifreezing agent according to claim 1, wherein the mixture A in the step (1) is prepared by mixing sodium alginate and chitosan according to a mass ratio of 1: 7-10.

5. The preparation method of the concrete antifreezing agent according to claim 1, wherein the mixed monomer in the step (3) is formaldehyde and acrylic acid which are uniformly mixed in a mass ratio of 10: 1-3.

6. The method for preparing a concrete antifreezer according to claim 1, wherein the surfactant in the step (3) is any one of alkylphenol ethoxylates and fatty acid polyoxyethylene esters.

Technical Field

The invention belongs to the technical field of concrete additives, and particularly relates to a preparation method of a concrete antifreezing agent.

Background

In construction work, concrete is one of the most widely used materials, and is a porous artificial stone that is manufactured under natural conditions and hardened for a certain period of time. In recent years, concrete structures in various countries around the world are damaged to different degrees, so that the use of concrete does not reach the expected service life, and the economic loss caused by the damage is not negligible. The durability of concrete is therefore a general concern, with freeze injury being one of the most important factors affecting the durability of concrete. The frost resistance and durability of the concrete are interesting to a plurality of scholars at home and abroad not only because the frost resistance and durability of the concrete are very important factors influencing the service life and the service quality of the concrete, but also because the frost damage of the concrete has a very wide range.

In severe cold areas, the phenomenon of freeze-thaw damage of hydraulic buildings occurs. At present, the problem of concrete frost damage by using additives is increasingly aroused by people, and the additives for solving the concrete frost damage are divided into two types: one is an admixture, called an air entraining agent, which increases the air content of concrete and generates fine, uniformly distributed bubbles, thereby improving the pore structure inside the concrete to improve the frost resistance of the concrete. The other is an additive which solves the problem of concrete freezing injury in winter construction by lowering the freezing point of the liquid phase of concrete, and is called an antifreeze. The antifreezing agent provides necessary water for hydration of cement in concrete, can change the crystal structure, enables the crystal to generate certain defects, enables the frost heaving stress generated by the transformation from a liquid phase to a solid phase due to the temperature reduction to be reduced, and further reduces the damage effect on the concrete.

The antifreezing agent is an admixture which can obviously reduce the freezing point under a certain negative temperature condition, so that the liquid phase of the concrete is not frozen or partially frozen, and the concrete is not subjected to freezing damage, thereby being a concrete admixture for solving the concrete construction in winter. Meanwhile, the hydration of water and cement is ensured, the strength increase of concrete and mortar is promoted under the condition of negative temperature, and the admixture with expected strength is obtained within a certain time. However, the prior antifreeze has large addition amount and poor antifreeze effect.

Disclosure of Invention

The technical problems to be solved by the invention are as follows: aiming at the problems of large antifreezing addition amount and poor antifreezing effect of the antifreezing agent, the preparation method of the concrete antifreezing agent is provided.

In order to solve the technical problems, the invention adopts the following technical scheme:

a preparation method of a concrete antifreezing agent comprises the following steps:

(1) putting the mixture, water and an auxiliary agent into a reactor according to the mass ratio of 7: 12-16: 1-3, uniformly stirring, adding a mixture A accounting for 20-30% of the mass of the mixture, protecting with nitrogen, adjusting the pH to 3-4, adding formaldehyde accounting for 25-40% of the mass of the mixture, heating, and preserving heat;

(2) after the heat preservation is finished, adding glutaraldehyde accounting for 13-16% of the mass of the mixture, uniformly stirring, preserving heat, cooling, discharging, freeze-drying, and collecting a dried substance;

(3) taking 160-180 parts of water, 50-55 parts of mixed monomer, 25-30 parts of urea, 15-20 parts of dry matter, 6-9 parts of ammonium chloride, 6-13 parts of polyacrylamide and 1-4 parts of surfactant according to parts by weight, putting the water, the mixed monomer, the dry matter and the surfactant into a reaction kettle, and uniformly stirring;

(4) after uniformly stirring, adding urea and ammonium chloride, adjusting pH, protecting with nitrogen, heating, stirring for reaction, cooling, adding polyacrylamide, stirring, standing, discharging, freeze-drying, and collecting freeze-dried product to obtain the concrete antifreezing agent.

The mixture in the step (1) is formed by mixing polyvinyl alcohol and polyacrylamide according to a mass ratio of 9: 2-4

The auxiliary agent in the step (1) is any one of sodium dodecyl benzene sulfonate and sodium dodecyl sulfate.

The mixture A in the step (1) is formed by mixing sodium alginate and chitosan according to a mass ratio of 1: 7-10.

And (3) uniformly mixing the formaldehyde and the acrylic acid in a mass ratio of 10: 1-3 to obtain the mixed monomer.

And (3) the surfactant is any one of alkylphenol ethoxylates and fatty acid polyoxyethylene esters.

Compared with other methods, the method has the beneficial technical effects that:

the invention takes polyvinyl alcohol and polyacrylamide as basic raw materials, plays a good role of dispersion by utilizing the function of an auxiliary agent, then is mixed with sodium alginate and chitosan, reacts by utilizing the function of formaldehyde and the function of a cross-linking agent of glutaraldehyde under an acidic condition to form a porous spongy gel structure, can improve the cohesiveness among the raw materials, can improve the energy storage effect, can well prevent freezing by energy storage, reacts urea and formaldehyde to form urea-formaldehyde resin which is wrapped and dispersed in the concrete, can well adsorb metal ions in the concrete, can well store energy and release heat by the function of the metal ions, and can well interfere the formation of ice crystals, so that the ice crystals are mutated and can not generate ice, thereby achieving good anti-freezing effect.

Detailed Description

The mixture is formed by mixing polyvinyl alcohol and polyacrylamide according to the mass ratio of 9: 2-4

The auxiliary agent is any one of sodium dodecyl benzene sulfonate and sodium dodecyl sulfate.

The mixture A is formed by mixing sodium alginate and chitosan according to a mass ratio of 1: 7-10.

The mixed monomer is prepared by uniformly mixing formaldehyde and acrylic acid according to the mass ratio of 10: 1-3.

The surfactant is any one of alkylphenol polyoxyethylene and polyoxyethylene fatty acid ester.

A preparation method of a concrete antifreezing agent comprises the following steps:

(1) putting the mixture, water and an auxiliary agent into a reactor according to the mass ratio of 7: 12-16: 1-3, uniformly stirring, adding a mixture A accounting for 20-30% of the mass of the mixture, protecting with nitrogen, adjusting the pH to 3-4, adding formaldehyde accounting for 25-40% of the mass of the mixture, heating to 80-90 ℃, and preserving heat for 6-9 hours;

(2) after the heat preservation is finished, adding glutaraldehyde accounting for 13-16% of the mass of the mixture, uniformly stirring, preserving the heat for 4-7 hours, cooling to room temperature, discharging, freeze-drying, and collecting a dried substance;

(3) taking 160-180 parts of water, 50-55 parts of mixed monomer, 25-30 parts of urea, 15-20 parts of dry matter, 6-9 parts of ammonium chloride, 6-13 parts of polyacrylamide and 1-4 parts of surfactant according to parts by weight, putting the water, the mixed monomer, the dry matter and the surfactant into a reaction kettle, and uniformly stirring;

(4) and after uniformly stirring, adding urea and ammonium chloride, regulating the pH value to 8-8.5 by using triethanolamine, carrying out nitrogen protection, heating to 80-90 ℃, stirring for reaction for 10-12 h, cooling to room temperature, adding polyacrylamide, stirring at 700r/min for 30min, standing for 10min, discharging, carrying out freeze drying, and collecting freeze-dried substances to obtain the concrete antifreezing agent.

Example 1

The mixture is formed by mixing polyvinyl alcohol and polyacrylamide according to the mass ratio of 9:4

The auxiliary agent is any one of sodium dodecyl benzene sulfonate and sodium dodecyl sulfate.

The mixture A is formed by mixing sodium alginate and chitosan according to the mass ratio of 1: 10.

The mixed monomer is prepared by uniformly mixing formaldehyde and acrylic acid according to the mass ratio of 10: 3.

The surfactant is any one of alkylphenol polyoxyethylene and polyoxyethylene fatty acid ester.

A preparation method of a concrete antifreezing agent comprises the following steps:

(1) putting the mixture, water and the auxiliary agent into a reactor according to the mass ratio of 7: 16:3, uniformly stirring, adding a mixture A accounting for 20-30% of the mass of the mixture, adjusting the pH to 4 under the protection of nitrogen, adding formaldehyde accounting for 40% of the mass of the mixture, heating to 90 ℃, and preserving heat for 9 hours;

(2) after the heat preservation is finished, adding glutaraldehyde with the mass of 16% of that of the mixture, uniformly stirring, preserving the heat for 7 hours, cooling to room temperature, discharging, freeze-drying, and collecting dried substances;

(3) taking 180 parts of water, 55 parts of mixed monomer, 30 parts of urea, 20 parts of dry matter, 9 parts of ammonium chloride, 13 parts of polyacrylamide and 4 parts of surfactant according to parts by weight, putting the water, the mixed monomer, the dry matter and the surfactant into a reaction kettle, and uniformly stirring;

(4) after uniformly stirring, adding urea and ammonium chloride, regulating the pH value to 8.5 by using triethanolamine, carrying out nitrogen protection, heating to 90 ℃, stirring and reacting for 12 hours, cooling to room temperature, adding polyacrylamide, stirring at 700r/min for 30 minutes, standing for 10 minutes, discharging, carrying out freeze drying, and collecting freeze-dried products to obtain the concrete antifreezing agent.

Example 2

The mixture is formed by mixing polyvinyl alcohol and polyacrylamide according to the mass ratio of 9:3

The auxiliary agent is any one of sodium dodecyl benzene sulfonate and sodium dodecyl sulfate.

The mixture A is formed by mixing sodium alginate and chitosan according to the mass ratio of 1: 8.

The mixed monomer is prepared by uniformly mixing formaldehyde and acrylic acid according to the mass ratio of 10: 2.

The surfactant is any one of alkylphenol polyoxyethylene and polyoxyethylene fatty acid ester.

A preparation method of a concrete antifreezing agent comprises the following steps:

(1) putting the mixture, water and the auxiliary agent into a reactor according to the mass ratio of 7:15:2, uniformly stirring, adding a mixture A accounting for 25% of the mass of the mixture, regulating the pH value to 3 under the protection of nitrogen, adding formaldehyde accounting for 30% of the mass of the mixture, heating to 85 ℃, and preserving heat for 8 hours;

(2) after the heat preservation is finished, adding glutaraldehyde accounting for 15% of the mass of the mixture, uniformly stirring, preserving the heat for 5 hours, cooling to room temperature, discharging, freeze-drying, and collecting a dried substance;

(3) according to the weight parts, 170 parts of water, 53 parts of mixed monomer, 28 parts of urea, 18 parts of dry matter, 8 parts of ammonium chloride, 10 parts of polyacrylamide and 3 parts of surfactant are taken, and the water, the mixed monomer, the dry matter and the surfactant are put into a reaction kettle and are uniformly stirred;

(4) after uniformly stirring, adding urea and ammonium chloride, regulating the pH value to 8 by using triethanolamine, carrying out nitrogen protection, heating to 85 ℃, stirring for reacting for 11h, cooling to room temperature, adding polyacrylamide, stirring for 30min at 700r/min, standing for 10min, discharging, carrying out freeze drying, and collecting freeze-dried substances to obtain the concrete antifreezing agent.

Example 3

The mixture is formed by mixing polyvinyl alcohol and polyacrylamide according to the mass ratio of 9:2

The auxiliary agent is any one of sodium dodecyl benzene sulfonate and sodium dodecyl sulfate.

The mixture A is formed by mixing sodium alginate and chitosan according to the mass ratio of 1: 7.

The mixed monomer is prepared by uniformly mixing formaldehyde and acrylic acid according to the mass ratio of 10: 1.

The surfactant is any one of alkylphenol polyoxyethylene and polyoxyethylene fatty acid ester.

A preparation method of a concrete antifreezing agent comprises the following steps:

(1) putting the mixture, water and the auxiliary agent into a reactor according to the mass ratio of 7:12:1, uniformly stirring, adding a mixture A accounting for 20% of the mass of the mixture, regulating the pH value to 3 under the protection of nitrogen, adding formaldehyde accounting for 25% of the mass of the mixture, heating to 80 ℃, and preserving heat for 6 hours;

(2) after the heat preservation is finished, adding glutaraldehyde accounting for 13% of the mass of the mixture, uniformly stirring, preserving the heat for 4 hours, cooling to room temperature, discharging, freeze-drying, and collecting a dried substance;

(3) taking 160 parts of water, 50 parts of mixed monomer, 25 parts of urea, 15 parts of dry matter, 6 parts of ammonium chloride, 6 parts of polyacrylamide and 1 part of surfactant according to parts by weight, putting the water, the mixed monomer, the dry matter and the surfactant into a reaction kettle, and uniformly stirring;

(4) after uniformly stirring, adding urea and ammonium chloride, regulating the pH value to 8 by using triethanolamine, carrying out nitrogen protection, heating to 80 ℃, stirring and reacting for 10 hours, cooling to room temperature, adding polyacrylamide, stirring at 700r/min for 30 minutes, standing for 10 minutes, discharging, carrying out freeze drying, and collecting freeze-dried substances to obtain the concrete antifreezing agent.

Comparative example 1

The mixture is formed by mixing polyvinyl alcohol and polyacrylamide according to the mass ratio of 9:2

The auxiliary agent is any one of sodium dodecyl benzene sulfonate and sodium dodecyl sulfate.

The mixed monomer is prepared by uniformly mixing formaldehyde and acrylic acid according to the mass ratio of 10: 1.

The surfactant is any one of alkylphenol polyoxyethylene and polyoxyethylene fatty acid ester.

A preparation method of a concrete antifreezing agent comprises the following steps:

(1) putting the mixture, water and the auxiliary agent into a reactor according to the mass ratio of 7:12:1, uniformly stirring, carrying out nitrogen protection, adjusting the pH to 3, adding formaldehyde accounting for 25% of the mass of the mixture, heating to 80 ℃, and carrying out heat preservation for 6 hours;

(2) after the heat preservation is finished, adding glutaraldehyde accounting for 13% of the mass of the mixture, uniformly stirring, preserving the heat for 4 hours, cooling to room temperature, discharging, freeze-drying, and collecting a dried substance;

(3) taking 160 parts of water, 50 parts of mixed monomer, 25 parts of urea, 15 parts of dry matter, 6 parts of ammonium chloride, 6 parts of polyacrylamide and 1 part of surfactant according to parts by weight, putting the water, the mixed monomer, the dry matter and the surfactant into a reaction kettle, and uniformly stirring;

(4) after uniformly stirring, adding urea and ammonium chloride, regulating the pH value to 8 by using triethanolamine, carrying out nitrogen protection, heating to 80 ℃, stirring and reacting for 10 hours, cooling to room temperature, adding polyacrylamide, stirring at 700r/min for 30 minutes, standing for 10 minutes, discharging, carrying out freeze drying, and collecting freeze-dried substances to obtain the concrete antifreezing agent.

Comparative example 2

The mixture is formed by mixing polyvinyl alcohol and polyacrylamide according to the mass ratio of 9:2

The auxiliary agent is any one of sodium dodecyl benzene sulfonate and sodium dodecyl sulfate.

The mixture A is formed by mixing sodium alginate and chitosan according to the mass ratio of 1: 7.

The surfactant is any one of alkylphenol polyoxyethylene and polyoxyethylene fatty acid ester.

A preparation method of a concrete antifreezing agent comprises the following steps:

(1) putting the mixture, water and the auxiliary agent into a reactor according to the mass ratio of 7:12:1, uniformly stirring, adding a mixture A accounting for 20% of the mass of the mixture, regulating the pH value to 3 under the protection of nitrogen, adding formaldehyde accounting for 25% of the mass of the mixture, heating to 80 ℃, and preserving heat for 6 hours;

(2) after the heat preservation is finished, adding glutaraldehyde accounting for 13% of the mass of the mixture, uniformly stirring, preserving the heat for 4 hours, cooling to room temperature, discharging, freeze-drying, and collecting a dried substance;

(3) taking 160 parts of water, 25 parts of urea, 15 parts of dry matter, 6 parts of ammonium chloride, 6 parts of polyacrylamide and 1 part of surfactant according to parts by weight, putting the water, the mixed monomer, the dry matter and the surfactant into a reaction kettle, and uniformly stirring;

(4) after uniformly stirring, adding urea and ammonium chloride, regulating the pH value to 8 by using triethanolamine, carrying out nitrogen protection, heating to 80 ℃, stirring and reacting for 10 hours, cooling to room temperature, adding polyacrylamide, stirring at 700r/min for 30 minutes, standing for 10 minutes, discharging, carrying out freeze drying, and collecting freeze-dried substances to obtain the concrete antifreezing agent.

Comparative example 3

The mixture is formed by mixing polyvinyl alcohol and polyacrylamide according to the mass ratio of 9:2

The auxiliary agent is any one of sodium dodecyl benzene sulfonate and sodium dodecyl sulfate.

The mixture A is formed by mixing sodium alginate and chitosan according to the mass ratio of 1: 7.

The mixed monomer is prepared by uniformly mixing formaldehyde and acrylic acid according to the mass ratio of 10: 1.

The surfactant is any one of alkylphenol polyoxyethylene and polyoxyethylene fatty acid ester.

A preparation method of a concrete antifreezing agent comprises the following steps:

(1) putting the mixture, water and the auxiliary agent into a reactor according to the mass ratio of 7:12:1, uniformly stirring, adding a mixture A accounting for 20% of the mass of the mixture, regulating the pH value to 3 under the protection of nitrogen, adding formaldehyde accounting for 25% of the mass of the mixture, heating to 80 ℃, and preserving heat for 6 hours;

(2) after the heat preservation is finished, uniformly stirring, preserving the heat for 4 hours, cooling to room temperature, discharging, freeze-drying, and collecting a dried substance;

(3) taking 160 parts of water, 50 parts of mixed monomer, 25 parts of urea, 15 parts of dry matter, 6 parts of ammonium chloride, 6 parts of polyacrylamide and 1 part of surfactant according to parts by weight, putting the water, the mixed monomer, the dry matter and the surfactant into a reaction kettle, and uniformly stirring;

(4) after uniformly stirring, adding urea and ammonium chloride, regulating the pH value to 8 by using triethanolamine, carrying out nitrogen protection, heating to 80 ℃, stirring and reacting for 10 hours, cooling to room temperature, adding polyacrylamide, stirring at 700r/min for 30 minutes, standing for 10 minutes, discharging, carrying out freeze drying, and collecting freeze-dried substances to obtain the concrete antifreezing agent.

The concrete antifreezes in the examples and the comparative examples were added in an amount of 3% by mass of the concrete, and then tested in accordance with the GB/T8077-2000 standard, and the test results are shown in Table 1.

TABLE 1

The concrete antifreezing agent has good antifreezing property and is worthy of great popularization.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, but rather as the subject matter of the invention is to be construed in all aspects and as broadly as possible, and all changes, equivalents and modifications that fall within the true spirit and scope of the invention are therefore intended to be embraced therein.