Composite polycarboxylic acid water reducer and preparation method thereof

Abstract

The invention provides a composite polycarboxylic acid water reducer and a preparation method thereof, and relates to the technical field of polycarboxylic acid water reducers. The composite polycarboxylate superplasticizer comprises the following raw materials: a polycarboxylate superplasticizer, sodium lignin sulfonate, acrylic acid, water-soluble cellulose ether, 2-ethylhexanol, gellan gum, an air entraining agent, a silane coupling agent and the like. Through compounding of specific raw materials, the composite polycarboxylic acid water reducing agent has the advantages of high water reducing rate, good slump retaining property, low solid blending amount, capability of improving the mechanical property of a hydraulic composition, adjustment of the flow rate, reduction of bleeding conditions and the like.

Description

Technical Field

[0001] The invention relates to the technical field of polycarboxylate water reducers, and in particular to a composite polycarboxylate water reducer and a preparation method thereof. Background Art

[0002] In order to improve the defects of cement-based materials or enhance the performance of cement-based materials, various organic admixtures are usually added in the preparation process of cement concrete. The invention and application of high-efficiency water reducer is recognized as the third technological leap in the field of concrete technology after reinforced concrete and prestressed reinforced concrete technology. Polycarboxylate water reducer (PCE) is widely used in the modern construction industry because of its advantages such as low dosage, good dispersion performance, high water reduction rate, low alkali content, chlorine-free and green environmental protection.

[0003] The interaction between cement and polycarboxylate water-reducing agent not only affects the fluidity of cement paste, but also has the potential to affect the performance of the material. Therefore, it is necessary to develop a high-performance composite polycarboxylate water-reducing agent that can adjust the fluidity of the paste, improve the comprehensive performance of the material, and reduce the dosage to reduce production costs. Summary of the invention

[0004] To solve the above problems, the present invention provides a composite polycarboxylic acid water-reducing agent, which has the advantages of high water reduction rate, good slump retention performance, low solid content, etc. through compounding of specific raw materials, and can improve the mechanical properties of hydraulic compositions, adjust their flow rate, and reduce water seepage.

[0005] The composite polycarboxylate water-reducing agent of the present invention comprises the following raw materials in parts by weight:

[0006] 80-120 parts of polycarboxylic acid water reducer, 20-100 parts of sodium lignin sulfonate, 20-40 parts of acrylic acid, 0.4-10 parts of water-soluble cellulose ether, 0.1-10 parts of 2-ethylhexanol, 0.2-4 parts of gellan gum, 0.2-1 parts of air entraining agent, and 0.1-1.5 parts of silane coupling agent.

[0007] Furthermore, the composite polycarboxylate water-reducing agent comprises the following raw materials in parts by weight:

[0008] 100 parts of polycarboxylate water reducer, 80 parts of sodium lignin sulfonate, 35 parts of acrylic acid, 2 parts of water-soluble cellulose ether, 0.2 parts of 2-ethylhexanol, 1.5 parts of gellan gum, 1.5 parts of air entraining agent, and 0.5 parts of silane coupling agent.

[0009] Furthermore, the polycarboxylic acid water-reducing agent is one or more of methyl allyl polyoxyethylene ether, polyethylene glycol monomethyl ether methacrylate, and isopentanol polyoxyethylene ether.

[0010] Further, the water-soluble cellulose ether is one or more of methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl methyl cellulose, and hydroxyethyl ethyl cellulose. Preferably, the water-soluble cellulose ether is one or more of methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl methyl cellulose, and hydroxyethyl ethyl cellulose. More preferably, the water-soluble cellulose ether is methyl cellulose and hydroxyethyl methyl cellulose, and the weight ratio of the methyl cellulose to the hydroxyethyl methyl cellulose is 5:(1-2).

[0011] Furthermore, the air entraining agent is one or more of triterpenoid saponins, alkylbenzene sulfonates, alkyl sulfonates, rosin resins, and fatty alcohol sulfonates.

[0012] Furthermore, the silane coupling agent is vinyl octadecyl silicate.

[0013] The preparation method of the composite polycarboxylate water-reducing agent of the present invention comprises the following steps:

[0014] S1, mixing polycarboxylate water reducer, sodium lignin sulfonate and acrylic acid to obtain a mixture A;

[0015] S2, mixing water-soluble cellulose ether, 2-ethylhexanol, gellan gum, an air entraining agent, and a silane coupling agent to obtain a mixture B;

[0016] S3. Mixture A and mixture B are stirred uniformly at a speed of 60 r / min to obtain a composite polycarboxylate water-reducing agent.

[0017] Compared with the prior art, the beneficial technical effects of the present invention are:

[0018] The composite polycarboxylate water reducer of the present invention has a high water reduction rate and good slump retention performance, can improve the mechanical properties of hydraulic compositions (concrete, mortar, cement slurry, etc.), improve their flow rate, and reduce water bleeding. At the same time, the present invention can reduce the water reducer solid content and reduce production costs through the synergistic effect between the raw materials. DETAILED DESCRIPTION

[0019] The technical solution provided by the present invention is further described below in conjunction with embodiments.

[0020] Example 1

[0021] A composite polycarboxylate water-reducing agent, composed of the following raw materials in parts by weight:

[0022] 100 parts of isopentanol polyoxyethylene ether, 80 parts of sodium lignin sulfonate, 35 parts of acrylic acid, 2 parts of water-soluble cellulose ether, 0.2 parts of 2-ethylhexanol, 1.5 parts of gellan gum, 1.5 parts of sodium dodecylbenzene sulfonate, and 0.5 parts of vinyl octadecyl silicate.

[0023] The water-soluble cellulose ether is composed of methyl cellulose and hydroxyethyl methyl cellulose in a weight ratio of 5:2.

[0024] The silane coupling agent is vinyl octadecyl silicate.

[0025] The preparation method of the composite polycarboxylate water reducer is as follows:

[0026] S1, mixing polycarboxylate water reducer, sodium lignin sulfonate and acrylic acid to obtain a mixture A;

[0027] S2, mixing water-soluble cellulose ether, 2-ethylhexanol, gellan gum, an air entraining agent, and a silane coupling agent to obtain a mixture B;

[0028] S3. Mixture A and mixture B are stirred uniformly at a speed of 60 r / min to obtain a composite polycarboxylate water-reducing agent.

[0029] Example 2

[0030] A composite polycarboxylate water-reducing agent, composed of the following raw materials in parts by weight:

[0031] 80 parts of isopentanol polyoxyethylene ether, 20 parts of sodium lignin sulfonate, 20 parts of acrylic acid, 0.4 parts of water-soluble cellulose ether, 0.1 parts of 2-ethylhexanol, 0.2 parts of gellan gum, 0.2 parts of sodium dodecylbenzene sulfonate, and 0.1 parts of vinyl octadecyl silicate.

[0032] The water-soluble cellulose ether is composed of methyl cellulose and hydroxyethyl methyl cellulose in a weight ratio of 5:2.

[0033] The preparation method of the composite polycarboxylate water reducer is as follows:

[0034] S1, mixing polycarboxylate water reducer, sodium lignin sulfonate and acrylic acid to obtain a mixture A;

[0035] S2, mixing water-soluble cellulose ether, 2-ethylhexanol, gellan gum, an air entraining agent, and a silane coupling agent to obtain a mixture B;

[0036] S3. Mixture A and mixture B are stirred uniformly at a speed of 60 r / min to obtain a composite polycarboxylate water-reducing agent.

[0037] Example 3

[0038] A composite polycarboxylate water-reducing agent, composed of the following raw materials in parts by weight:

[0039] 120 parts of isopentanol polyoxyethylene ether, 100 parts of sodium lignin sulfonate, 40 parts of acrylic acid, 10 parts of water-soluble cellulose ether, 10 parts of 2-ethylhexanol, 4 parts of gellan gum, 1 part of sodium dodecylbenzene sulfonate, and 1.5 parts of vinyl octadecyl silicate.

[0040] The water-soluble cellulose ether is composed of methyl cellulose and hydroxyethyl methyl cellulose in a weight ratio of 5:2.

[0041] The preparation method of the composite polycarboxylate water reducer is as follows:

[0042] S1, mixing polycarboxylate water reducer, sodium lignin sulfonate and acrylic acid to obtain a mixture A;

[0043] S2, mixing water-soluble cellulose ether, 2-ethylhexanol, gellan gum, an air entraining agent, and a silane coupling agent to obtain a mixture B;

[0044] S3. Mixture A and mixture B are stirred uniformly at a speed of 60 r / min to obtain a composite polycarboxylate water-reducing agent.

[0045] Comparative Example 1

[0046] The same as Example 1, except that: the composite polycarboxylate water-reducing agent is composed of the following raw materials in parts by weight:

[0047] 100 parts of isopentanol polyoxyethylene ether, 80 parts of sodium lignin sulfonate, 35 parts of acrylic acid, 0.2 parts of 2-ethylhexanol, 1.5 parts of gellan gum, 1.5 parts of sodium dodecylbenzene sulfonate, and 0.5 parts of vinyl octadecyl silicate.

[0048] Comparative Example 2

[0049] The same as Example 1, except that: the composite polycarboxylate water-reducing agent is composed of the following raw materials in parts by weight:

[0050] 100 parts of isopentanol polyoxyethylene ether, 80 parts of sodium lignin sulfonate, 35 parts of acrylic acid, 2 parts of water-soluble cellulose ether, 0.2 parts of 2-ethylhexanol, 1.5 parts of sodium dodecylbenzene sulfonate, and 0.5 parts of vinyl octadecyl silicate.

[0051] Comparative Example 3

[0052] The same as Example 1, except that: the composite polycarboxylate water-reducing agent is composed of the following raw materials in parts by weight:

[0053] 100 parts of isopentanol polyoxyethylene ether, 80 parts of sodium lignin sulfonate, 35 parts of acrylic acid, 2 parts of water-soluble cellulose ether, 0.2 parts of 2-ethylhexanol, 1.5 parts of gellan gum, and 1.5 parts of sodium dodecylbenzene sulfonate.

[0054] Comparative Example 4

[0055] The same as Example 1, except that: the composite polycarboxylate water-reducing agent is composed of the following raw materials in parts by weight:

[0056] 100 parts of isopentanol polyoxyethylene ether, 80 parts of sodium lignin sulfonate, 35 parts of acrylic acid, 2 parts of water-soluble cellulose ether, 1.5 parts of gellan gum, 1.5 parts of sodium dodecylbenzene sulfonate, and 0.5 parts of vinyl octadecyl silicate.

[0057] Test Example 1

[0058] The stability of the products obtained in Examples 1-3 and Comparative Examples 1-4 was tested as follows:

[0059] The composite polycarboxylate water-reducing agent prepared in the embodiment and the comparative example was used in the preparation of concrete. The raw material ratio of the concrete was as follows: 50 parts by weight of PO42.5 cement, 60 parts by weight of sand, 110 parts by weight of crushed stone, 18 parts by weight of water, and 0.15% of the water-reducing agent in terms of solid content.

[0060] The performance of concrete was tested and the results are as follows:

[0061]

[0062]

[0063] It can be seen that in the present invention, cellulose ether, gellan gum and 2-ethylhexanol have an influence on the slump of concrete. Among them, cellulose ether has an influence on the initial slump, but as time goes on, its influence on the slump gradually decreases. At the same time, cellulose ether, gellan gum and 2-ethylhexanol also have an influence on the strength of concrete, wherein cellulose ether and 2-ethylhexanol will affect the early strength of concrete, while gellan gum will affect the later strength of concrete. Finally, cellulose ether, gellan gum and vinyl octadecyl silicate will affect the water reduction rate of water reducing agent, wherein, the influence of vinyl octadecyl silicate is the most significant. Finally, gellan gum and vinyl octadecyl silicate can also alleviate the bleeding of concrete.

[0064] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A composite polycarboxylate water reducer, characterized in that: The invention comprises the following raw materials in parts by weight: 80-120 parts of polycarboxylic acid water reducer, 20-100 parts of sodium lignin sulfonate, 20-40 parts of acrylic acid, 0.4-10 parts of water-soluble cellulose ether, 0.1-10 parts of 2-ethylhexanol, 0.2-4 parts of gellan gum, 0.2-1 parts of air entraining agent, and 0.1-1.5 parts of silane coupling agent.

2. A composite polycarboxylate water reducer according to claim 1, characterized in that: The composite polycarboxylate water-reducing agent comprises the following raw materials in parts by weight: 100 parts of polycarboxylate water reducer, 80 parts of sodium lignin sulfonate, 35 parts of acrylic acid, 2 parts of water-soluble cellulose ether, 0.2 parts of 2-ethylhexanol, 1.5 parts of gellan gum, 1.5 parts of air entraining agent, and 0.5 parts of silane coupling agent.

3. A composite polycarboxylate water reducer according to claim 1, characterized in that: The polycarboxylic acid water reducer is one or more of methyl allyl polyoxyethylene ether, polyethylene glycol monomethyl ether methacrylate, and isopentanol polyoxyethylene ether.

4. A composite polycarboxylate water reducer according to claim 1, characterized in that: The water-soluble cellulose ether is one or more of methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl methyl cellulose and hydroxyethyl ethyl cellulose.

5. A composite polycarboxylate water reducer according to claim 1, characterized in that: The air entraining agent is one or more of triterpenoid saponin, alkylbenzene sulfonate, alkyl sulfonate, rosin resin, and fatty alcohol sulfonate.

6. A composite polycarboxylate water reducer according to claim 1, characterized in that: The silane coupling agent is vinyl octadecyl silicate.

7. The method for preparing the composite polycarboxylate water-reducing agent according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1, mixing polycarboxylate water reducer, sodium lignin sulfonate and acrylic acid to obtain a mixture A; S2, mixing water-soluble cellulose ether, 2-ethylhexanol, gellan gum, an air entraining agent, and a silane coupling agent to obtain a mixture B; S3. Mixture A and mixture B are stirred uniformly at a speed of 60 r / min to obtain a composite polycarboxylate water-reducing agent.

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