Slump-retaining polycarboxylate superplasticizer and preparation process thereof

Abstract

The slump-retaining polycarboxylate superplasticizer is prepared from the following components in parts by weight: 150 to 200 parts of ether macromonomers, 5 to 15 parts of unsaturated carboxylic acid, 1 to 3 parts of an initiator, 1 to 2 parts of a chain transfer agent, 0.1 to 0.5 part of a reducing agent, 4 to 10 parts of unsaturated small monomers, 20 to 25 parts of hydroxyethyl methylacrylate, 1 to 2 parts of a pH regulator, 0.1 to 0.3 part of a de-foaming agent and 1 to 3 parts of a ferrous sulfate solution. And the balance of deionized water. The invention belongs to the technical field of preparation of polycarboxylate superplasticizers, through a chemical synthesis method, the polycarboxylate superplasticizer mother liquor has the advantages of low mixing amount, long slump retaining time and strong mud resistance, the early strength development of concrete is fast, the green and environment-friendly performance is high, the adverse effect of mud-containing aggregate in the concrete on the workability of the concrete can be reduced, and the service life of the concrete is prolonged. The raw materials are easily available, the preparation process is simple, and the production cost is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of polycarboxylate water reducer preparation, and specifically refers to a collapse-retaining polycarboxylate water reducer and a preparation process thereof. Background Art

[0002] The scale of urban infrastructure construction in my country continues to expand, and the real estate industry develops rapidly. Concrete, as one of the most commonly used building materials, has been widely used in many projects, and different types of projects have different requirements for the various properties of concrete. As the third-generation water reducer, the use of polycarboxylic acid water reducer in various projects has become a normal practice because the comprehensive performance of the concrete it mixes meets the requirements of pumping construction quality.

[0003] In the prior art, as the quality volatility of different floor materials increases, unfavorable phenomena such as poor workability of fresh concrete, low water reduction rate, and excessive slump loss over time are prone to occur. In addition, the retarding effect of ordinary polycarboxylic acid water reducers will affect the hydration of cement, causing the early strength development of concrete to be slow, and the green environmental protection performance is not high. Therefore, the current ready-mixed concrete industry has put forward higher requirements on the working performance of polycarboxylic acid water reducers, especially the initial dispersion and retention performance. Summary of the invention

[0004] In order to solve the above existing problems, the present invention provides a collapse-retaining polycarboxylic acid water-reducing agent and a preparation process thereof.

[0005] The technical scheme adopted by the present invention is as follows: a collapse-retaining polycarboxylic acid water-reducing agent and a preparation process thereof, comprising the following components by weight: 150-200 parts of an ether macromonomer, 5-15 parts of an unsaturated carboxylic acid, 1-3 parts of an initiator, 1-2 parts of a chain transfer agent, 0.1-0.5 parts of a reducing agent, 4-10 parts of an unsaturated small monomer, 20-25 parts of hydroxyethyl methacrylate, 1-2 parts of a pH regulator, 0.1-0.3 parts of a defoaming agent, 1-3 parts of a ferrous sulfate solution, and the balance being deionized water.

[0006] Furthermore, a collapse-retaining polycarboxylic acid water-reducing agent and a preparation process thereof include the following components by weight: 160-190 parts of an ether macromonomer, 6-14 parts of an unsaturated carboxylic acid, 1.5-2.5 parts of an initiator, 1.2-1.8 parts of a chain transfer agent, 0.2-0.4 parts of a reducing agent, 5-9 parts of an unsaturated small monomer, 21-24 parts of hydroxyethyl methacrylate, 1.2-1.8 parts of a pH regulator, 0.2-0.3 parts of a defoaming agent, 1.5-2.5 parts of a ferrous sulfate solution, and the balance being deionized water.

[0007] Furthermore, a collapse-retaining polycarboxylic acid water-reducing agent and a preparation process thereof include the following components by weight: 180 parts of an ether macromonomer, 10 parts of an unsaturated carboxylic acid, 2 parts of an initiator, 1.5 parts of a chain transfer agent, 0.3 parts of a reducing agent, 7 parts of an unsaturated small monomer, 23 parts of hydroxyethyl methacrylate, 1.5 parts of a pH regulator, 0.2 parts of a defoaming agent, 2 parts of a ferrous sulfate solution, and the balance being deionized water.

[0008] The present invention also discloses a preparation process of a collapse-retaining polycarboxylate water-reducing agent, comprising the following steps:

[0009] Step 1: Add ether macromonomer and initiator into the reaction device, and stir the ether macromonomer and initiator at 45-55° C. until they are completely dissolved;

[0010] Step 2: Continue to add pH regulator to the reaction device to adjust the pH to 8-10, and stir for 5 hours;

[0011] Step 3: adding sodium chloride and hydrochloric acid to the reaction device, separating the solution obtained after stirring in the reaction device, and retaining the organic phase;

[0012] Step 4: Filter the organic phase, remove the solvent from the filtrate and perform reduced pressure distillation to obtain the functional monomer DM;

[0013] Step 5: Add unsaturated small monomer, chain transfer agent and deionized water into the second reaction device, and stir and dissolve at 15-30°C;

[0014] Step 6: uniformly mix the functional monomer DM, unsaturated carboxylic acid and deionized water obtained in step 4, and place them in a first dropping device;

[0015] Step 7: uniformly mix the reducing agent, hydroxyethyl methacrylate and deionized water and place them in a second dropping device;

[0016] Step 8: directly add ferrous sulfate solution and initiator to the second reaction device, stir for 5 to 8 minutes, add defoamer, and then drop the mixed materials in the first dropping device and the second dropping device in sequence, and complete the dropwise addition within 1 to 3 hours, and maintain constant temperature for 1 to 1.5 hours.

[0017] Step nine: adding sodium hydroxide solution to the material obtained in step S2 to adjust the pH value to 5.0-7.0, thereby obtaining a collapse-retaining polycarboxylic acid water-reducing agent.

[0018] Furthermore, the mass concentration of the ferrous sulfate solution added in step eight is 1%, and the mass concentration of the sodium hydroxide solution added in step nine is 1%.

[0019] The present invention achieves the following beneficial effects by adopting the above scheme: the slump-retaining polycarboxylate water-reducing agent of the present invention is synthesized by a chemical method, and the polycarboxylate water-reducing agent mother liquor has the advantages of low dosage, long slump-retaining time and strong anti-mud performance, and the early strength of concrete develops rapidly, and the green environmental protection performance is high. It can reduce the adverse effect of mud-containing aggregate in concrete on the workability of concrete, and the raw materials are easy to obtain and the preparation process is simple, which is conducive to reducing production costs. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Example 1. A collapse-retaining polycarboxylic acid water-reducing agent and a preparation process thereof of the present invention comprise the following components by weight: 200 parts of an ether macromonomer, 15 parts of an unsaturated carboxylic acid, 3 parts of an initiator, 2 parts of a chain transfer agent, 0.5 parts of a reducing agent, 10 parts of an unsaturated small monomer, 25 parts of hydroxyethyl methacrylate, 2 parts of a pH regulator, 0.3 parts of a defoaming agent, 3 parts of a ferrous sulfate solution, and the balance being deionized water.

[0022] The present invention also discloses a preparation process of a collapse-retaining polycarboxylate water-reducing agent, comprising the following steps:

[0023] Step 1: Add ether macromonomer and initiator into the reaction device, and stir the ether macromonomer and initiator at 55° C. until they are completely dissolved;

[0024] Step 2: Continue to add pH regulator to the reaction device to adjust the pH to 10 and stir for 5 hours;

[0025] Step 3: adding sodium chloride and hydrochloric acid to the reaction device, separating the solution obtained after stirring in the reaction device, and retaining the organic phase;

[0026] Step 4: Filter the organic phase, remove the solvent from the filtrate and perform reduced pressure distillation to obtain the functional monomer DM;

[0027] Step 5: Add unsaturated small monomer, chain transfer agent and deionized water into the second reaction device, and stir and dissolve at 30°C;

[0028] Step 6: uniformly mix the functional monomer DM, unsaturated carboxylic acid and deionized water obtained in step 4, and place them in a first dropping device;

[0029] Step 7: uniformly mix the reducing agent, hydroxyethyl methacrylate and deionized water and place them in a second dropping device;

[0030] Step 8: directly add ferrous sulfate solution and initiator to the second reaction device, stir for 8 minutes, add defoamer, and then drop the mixed materials in the first dropping device and the second dropping device in sequence, and complete the dropwise addition within 3 hours, and maintain constant temperature for 1.5 hours.

[0031] Step nine: Add sodium hydroxide solution to the material obtained in step S2 to adjust the pH value to 7.0, thereby obtaining a collapse-retaining polycarboxylate water-reducing agent.

[0032] Furthermore, the mass concentration of the ferrous sulfate solution added in step eight is 1%, and the mass concentration of the sodium hydroxide solution added in step nine is 1%.

[0033] Example 2. A collapse-retaining polycarboxylic acid water-reducing agent and a preparation process thereof of the present invention comprise the following components by weight: 150 parts of an ether macromonomer, 5 parts of an unsaturated carboxylic acid, 1 part of an initiator, 1 part of a chain transfer agent, 0.1 parts of a reducing agent, 4 parts of an unsaturated small monomer, 20 parts of hydroxyethyl methacrylate, 1 part of a pH regulator, 0.1 parts of a defoaming agent, 1 part of a ferrous sulfate solution, and the remainder being deionized water.

[0034] The present invention also discloses a preparation process of a collapse-retaining polycarboxylate water-reducing agent, comprising the following steps:

[0035] Step 1: Add ether macromonomer and initiator into the reaction device, and stir the ether macromonomer and initiator at 45° C. until they are completely dissolved;

[0036] Step 2: Continue to add pH regulator to the reaction device to adjust the pH to 8 and stir for 5 hours;

[0037] Step 3: adding sodium chloride and hydrochloric acid to the reaction device, separating the solution obtained after stirring in the reaction device, and retaining the organic phase;

[0038] Step 4: Filter the organic phase, remove the solvent from the filtrate and perform reduced pressure distillation to obtain the functional monomer DM;

[0039] Step 5: Add unsaturated small monomer, chain transfer agent and deionized water into the second reaction device, and stir and dissolve at 15°C;

[0040] Step 6: uniformly mix the functional monomer DM, unsaturated carboxylic acid and deionized water obtained in step 4, and place them in a first dropping device;

[0041] Step 7: uniformly mix the reducing agent, hydroxyethyl methacrylate and deionized water and place them in a second dropping device;

[0042] Step 8: directly add ferrous sulfate solution and initiator to the second reaction device, stir for 5 minutes, add defoamer, and then drop the mixed materials in the first dropping device and the second dropping device in sequence, and complete the dropwise addition within 1 to 3 hours, and maintain constant temperature for 1 hour.

[0043] Step nine: Add sodium hydroxide solution to the material obtained in step S2 to adjust the pH value to 5.0, thereby obtaining a collapse-retaining polycarboxylate water-reducing agent.

[0044] Furthermore, the mass concentration of the ferrous sulfate solution added in step eight is 1%, and the mass concentration of the sodium hydroxide solution added in step nine is 1%.

[0045] Example 3, a collapse-retaining polycarboxylic acid water-reducing agent and a preparation process thereof of the present invention, comprising the following components by weight: 180 parts of an ether macromonomer, 10 parts of an unsaturated carboxylic acid, 2 parts of an initiator, 1.5 parts of a chain transfer agent, 0.3 parts of a reducing agent, 7 parts of an unsaturated small monomer, 23 parts of hydroxyethyl methacrylate, 1.5 parts of a pH regulator, 0.2 parts of a defoaming agent, 2 parts of a ferrous sulfate solution, and the balance being deionized water.

[0046] The present invention also discloses a preparation process of a collapse-retaining polycarboxylate water-reducing agent, comprising the following steps:

[0047] Step 1: Add ether macromonomer and initiator into the reaction device, and stir the ether macromonomer and initiator at 50° C. until they are completely dissolved;

[0048] Step 2: Continue to add pH regulator to the reaction device to adjust the pH to 9 and stir for 5 hours;

[0049] Step 3: adding sodium chloride and hydrochloric acid to the reaction device, separating the solution obtained after stirring in the reaction device, and retaining the organic phase;

[0050] Step 4: Filter the organic phase, remove the solvent from the filtrate and perform reduced pressure distillation to obtain the functional monomer DM;

[0051] Step 5: Add unsaturated small monomer, chain transfer agent and deionized water into the second reaction device, and stir and dissolve at 20°C;

[0052] Step 6: uniformly mix the functional monomer DM, unsaturated carboxylic acid and deionized water obtained in step 4, and place them in a first dropping device;

[0053] Step 7: uniformly mix the reducing agent, hydroxyethyl methacrylate and deionized water and place them in a second dropping device;

[0054] Step 8: directly add ferrous sulfate solution and initiator to the second reaction device, stir for 7 minutes, add defoamer, and then drop the mixed materials in the first dropping device and the second dropping device in sequence, and complete the dropwise addition within 2 hours, and maintain constant temperature for 1.3 hours.

[0055] Step nine: Add sodium hydroxide solution to the material obtained in step S2 to adjust the pH value to 6.0, thereby obtaining a collapse-retaining polycarboxylate water-reducing agent.

[0056] Furthermore, the mass concentration of the ferrous sulfate solution added in step eight is 1%, and the mass concentration of the sodium hydroxide solution added in step nine is 1%.

[0057] It should be noted that, in this article, the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0058] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

[0059] The present invention and its implementation methods are described above, and such description is not restrictive. In short, if ordinary technicians in the field are inspired by it, without departing from the purpose of the invention, they can design structures and embodiments similar to the technical solution without creativity, which should all fall within the protection scope of the present invention.

Claims

1. A collapse-retaining polycarboxylate water-reducing agent and a preparation process thereof, characterized in that: The invention comprises the following components by weight: 150-200 parts of ether macromonomer, 5-15 parts of unsaturated carboxylic acid, 1-3 parts of initiator, 1-2 parts of chain transfer agent, 0.1-0.5 parts of reducing agent, 4-10 parts of unsaturated small monomer, 20-25 parts of hydroxyethyl methacrylate, 1-2 parts of pH regulator, 0.1-0.3 parts of defoaming agent, 1-3 parts of ferrous sulfate solution, and the balance is deionized water.

2. A collapse-retaining polycarboxylate water-reducing agent and a preparation process thereof according to claim 1, characterized in that: The invention comprises the following components by weight: 160-190 parts of ether macromonomer, 6-14 parts of unsaturated carboxylic acid, 1.5-2.5 parts of initiator, 1.2-1.8 parts of chain transfer agent, 0.2-0.4 parts of reducing agent, 5-9 parts of unsaturated small monomer, 21-24 parts of hydroxyethyl methacrylate, 1.2-1.8 parts of pH regulator, 0.2-0.3 parts of defoaming agent, 1.5-2.5 parts of ferrous sulfate solution, and the balance is deionized water.

3. A collapse-retaining polycarboxylate water-reducing agent and a preparation process thereof according to claim 2, characterized in that: The invention comprises the following components by weight: 180 parts of ether macromonomer, 10 parts of unsaturated carboxylic acid, 2 parts of initiator, 1.5 parts of chain transfer agent, 0.3 parts of reducing agent, 7 parts of unsaturated small monomer, 23 parts of hydroxyethyl methacrylate, 1.5 parts of pH regulator, 0.2 parts of defoaming agent, 2 parts of ferrous sulfate solution, and the balance is deionized water.

4. A collapse-retaining polycarboxylate water-reducing agent and a preparation process thereof according to claims 1 to 3, characterized in that: The steps include: Step 1: Add ether macromonomer and initiator into the reaction device, and stir the ether macromonomer and initiator at 45-55° C. until they are completely dissolved; Step 2: Continue to add pH regulator to the reaction device to adjust the pH to 8-10, and stir for 5 hours; Step 3: adding sodium chloride and hydrochloric acid to the reaction device, separating the solution obtained after stirring in the reaction device, and retaining the organic phase; Step 4: Filter the organic phase, remove the solvent from the filtrate and perform vacuum distillation to obtain the functional monomer DM; Step 5: Add the unsaturated small monomer, chain transfer agent and deionized water into the second reaction device, and stir and dissolve at 15-30°C; Step 6: uniformly mix the functional monomer DM, unsaturated carboxylic acid and deionized water obtained in step 4, and place them in a first dropping device; Step 7: uniformly mix the reducing agent, hydroxyethyl methacrylate and deionized water and place them in a second dropping device; Step 8: directly add ferrous sulfate solution and initiator to the second reaction device, stir for 5 to 8 minutes, add defoamer, and then drop the mixed materials in the first dropping device and the second dropping device in sequence, and complete the dropwise addition within 1 to 3 hours, and maintain constant temperature for 1 to 1.5 hours. Step nine: adding sodium hydroxide solution to the material obtained in step S2 to adjust the pH value to 5.0-7.0, thereby obtaining a collapse-retaining polycarboxylic acid water-reducing agent.

5. A collapse-retaining polycarboxylate water-reducing agent and a preparation process thereof according to claim 4, characterized in that: The mass concentration of the ferrous sulfate solution added in step eight is 1%, and the mass concentration of the sodium hydroxide solution added in step nine is 1%.