阅读说明：本技术 一种功能型聚羧酸减水剂 (Functional polycarboxylate superplasticizer ) 是由 卢通 钱珊珊 王学川 赵旭 彭荩影 屈浩杰 于鹏程 郑春扬 于 2021-09-15 设计创作，主要内容包括：本发明公开了一种功能型聚羧酸减水剂,通过在侧链上引入疏水基团苯结构及四氮唑结构,最终获得了一种集减缩与抗菌功能的聚羧酸减水剂。本发明产品无毒无污染,性能优良且稳定,可长期、高温储存,产品制备方法简单,适合大规模工业化生产。(The invention discloses a functional polycarboxylate superplasticizer, which is prepared by introducing a hydrophobic group benzene structure and a tetrazole structure on a side chain. The product of the invention has no toxicity and pollution, excellent and stable performance, can be stored at high temperature for a long time, has simple preparation method, and is suitable for large-scale industrial production.)

1. A functional polycarboxylate water reducing agent is characterized in that: has the following structure:

in the formula, the polymerization degrees n and m are respectively and independently 1-100; the polymerization degrees r and q are respectively 0-20 and are not 0 at the same time; the polymerization degree p is 10 to 200.

2. The functional polycarboxylate superplasticizer according to claim 1, characterized in that: m is one or the combination of two of phenyl or biphenyl.

3. The functional polycarboxylate superplasticizer according to claim 1, characterized in that: r₁Is one or a combination of two or more of H, alkali metal ions, alkyl containing 1 to 6 carbon atoms, hydroxyalkyl containing 1 to 6 carbon atoms, alkoxy containing 1 to 6 carbon atoms, phenyl or phenyl derivatives.

4. The functional polycarboxylate superplasticizer according to claim 1, characterized in that: r₂Is one or the combination of two of H or methyl.

5. The functional polycarboxylate superplasticizer according to claim 1, characterized in that: the weight average molecular weight of the functional polycarboxylate superplasticizer is 10000 g/mol-100000 g/mol.

Technical Field

The invention relates to the field of polycarboxylic acid water reducing agents for cement concrete, and particularly relates to a functional polycarboxylic acid water reducing agent.

Background

The polycarboxylic acid high-performance water reducing agent is widely applied to projects such as railways, bridges, airports, house construction and the like, and greatly promotes the process of modern development. With the increase of the usage amount of the high-performance concrete, the requirements on the storage performance and the service performance of the high-performance concrete admixture are also increased.

Regarding the problem of shrinkage of concrete, most of the solutions at present are to mix an expanding agent or fibers into the concrete, but the problem of moderate mixing amount of the expanding agent and the problem of economic adaptability of the fibers are also exposed. Therefore, starting from the aspect of concrete admixture structure, the method for reducing the surface tension of water in concrete so as to reduce the contraction force of water evaporation and achieve the aims of cracking resistance and shrinkage reduction becomes the hot research. The patent with the publication number of CN106380550A and the publication date of 2017, 2 and 8 and the name of 'a surface tension adjustment and reduction type polycarboxylate water reducer and a preparation method thereof' discloses a polycarboxylate water reducer achieving a reduction effect by introducing hydrophobic groups to adjust the surface tension and a preparation method thereof.

The polycarboxylate superplasticizer with the shrinkage reducing effect is synthesized from the structure of the polycarboxylate superplasticizer, and besides the shrinkage reducing effect, the structure also endows the polycarboxylate superplasticizer with the antibacterial and anticorrosive effects, so that the polycarboxylate superplasticizer can have good storage performance and use performance. At present, most of polycarboxylic acid water reducing agents are compounded by water reducing agents, slump retaining agents, retarder and the like, the commonly used retarder comprises substances such as white sugar and malt, and when the polycarboxylic acid water reducing agents are stored or transported in high-temperature climates or places, under the influence of compounded small white sugar or malt, bacteria or fungi can be bred, the performance of the water reducing agents is influenced, and therefore the performance of concrete is influenced. The existing solution is mainly to add some antibacterial preservatives into the water reducing agent, but the method is not environment-friendly enough and has high cost.

A patent with the publication number of CN107698721A, publication date of 2018, 2 month and 16 days and the name of 'a branched-chain antibacterial polycarboxylic acid water reducing agent, a preparation method and application thereof' reports a branched-chain antibacterial polycarboxylic acid water reducing agent, an imidazole salt structure is formed on a branched chain of the polycarboxylic acid water reducing agent, so that the branched-chain antibacterial polycarboxylic acid water reducing agent has an antibacterial effect, but the use of the branched-chain antibacterial polycarboxylic acid water reducing agent is limited by large use amount of functional monomers and high cost. The patent with the publication number of CN109400819A and the publication date of 2019, 3 and 1 discloses that the patent is named as 'a viscosity-reducing antibacterial amphoteric polycarboxylic acid high-efficiency water reducing agent and a preparation method thereof', and discloses a polycarboxylic acid water reducing agent with viscosity-reducing and antibacterial effects and a preparation method thereof.

From the structure, the synthesis of the polycarboxylate superplasticizer with the shrinkage reducing effect or the antibacterial effect is reported more, but the polycarboxylate superplasticizer with the shrinkage reducing effect and the antibacterial effect is reported only rarely, so that the method has higher innovation and marketability.

Disclosure of Invention

1. The technical problem to be solved is as follows:

aiming at the technical problems, the functional polycarboxylate superplasticizer provided by the invention is prepared by introducing a hydrophobic group benzene structure and a tetrazole structure on a side chain from the structure of the polycarboxylate superplasticizer, and finally obtains the polycarboxylate superplasticizer with the functions of shrinkage reduction and antibiosis. On one hand, the water reducer disclosed by the invention solves the problem that the existing water reducer has high shrinkage on concrete; on the other hand, the problem of bacteria and fungi which are bred in the storage or transportation process of the existing water reducing agent is solved.

2. The technical scheme is as follows:

a functional polycarboxylate water reducing agent is characterized in that: has the following structure:

in the formula, the polymerization degrees n and m are respectively and independently 1-100; the polymerization degrees r and q are respectively 0-20 and are not 0 at the same time; the polymerization degree p is 10 to 200.

Further, M is one or a combination of two of phenyl or biphenyl.

Further, R₁Is one or a combination of two or more of H, alkali metal ions, alkyl containing 1 to 6 carbon atoms, hydroxyalkyl containing 1 to 6 carbon atoms, alkoxy containing 1 to 6 carbon atoms, phenyl or phenyl derivatives.

Further, R₂Is one or the combination of two of H or methyl.

Further, the weight average molecular weight of the functional polycarboxylate superplasticizer is 10000 g/mol-100000 g/mol.

3. Has the advantages that:

(1) the polycarboxylate superplasticizer prepared by the invention can reduce the surface tension of water in concrete by endowing the superplasticizer with a stable hydrophobic benzene (biphenyl) structure, thereby reducing the problem of shrinkage caused by water evaporation.

(2) The polycarboxylate superplasticizer prepared by the invention can endow the superplasticizer with a stable tetrazole structure, so that the superplasticizer has antibacterial and anticorrosive capabilities.

(3) The polycarboxylic acid water reducing agent prepared by the invention has excellent storage performance and excellent performance; the preparation process is simple, convenient, safe, reliable and pollution-free; and the raw materials are convenient to obtain and low in price.

Detailed Description

A functional polycarboxylate water reducing agent is characterized in that: has the following structure:

in the formula, the polymerization degrees n and m are respectively and independently 1-100; the polymerization degrees r and q are respectively 0-20 and are not 0 at the same time; the polymerization degree p is 10 to 200.

Further, M is one or a combination of two of phenyl or biphenyl.

Further, R₁Is one or a combination of two or more of H, alkali metal ions, alkyl containing 1 to 6 carbon atoms, hydroxyalkyl containing 1 to 6 carbon atoms, alkoxy containing 1 to 6 carbon atoms, phenyl or phenyl derivatives.

Further, R₂Is one or the combination of two of H or methyl.

Further, the weight average molecular weight of the functional polycarboxylate superplasticizer is 10000 g/mol-100000 g/mol

The water reducing agent can be prepared by the following steps:

step S01: preparation of prepolymer A: carrying out free radical polymerization reaction (3-5) on a p-hydroxy benzene/diphenyl styrene monomer and an unsaturated carboxylic acid monomer at the temperature of (25-50) DEG C under the combined action of an initiator, a reducing agent and a molecular weight regulator for 3-5 h to prepare a prepolymer A.

Step S02: preparing a prepolymer B containing tetrazole: and (2) reacting the prepolymer A obtained in the step (S01) with dihalogenobenzonitrile and hydroquinone/4, 4' -biphenol under the action of N-methyl-2-pyrrolidone (NMP) and an acid-binding agent, refluxing the reaction product with sodium azide in a mixed solution of a solvent and water at the temperature of 50-150 ℃, and generating a prepolymer B containing tetrazole under the catalysis of ammonium chloride/zinc chloride for 3-10 hours.

Step S03: preparing a functional polycarboxylic acid water reducing agent: and (3) reacting the prepolymer B containing tetrazole with halogen-terminated polyethylene glycol monomethyl ether for 1-2 h to obtain the polycarboxylic acid water reducer with the functions of shrinkage reduction and antibiosis.

Wherein the molar ratio of the unsaturated carboxylic acid monomer, the p-hydroxy benzene/distyryl monomer, the initiator, the reducing agent and the molecular weight regulator is (3-10) to 1, (0.02-0.15) to (0.02-0.25) to (0.02-0.15).

In step S01, the p-hydroxy-benzene/bi-styrene monomer is any one or a combination of two of 4-hydroxy-styrene and 4- (4-vinyl benzene) phenol.

In step S01, the unsaturated carboxylic acid monomer is any one or a combination of two of acrylic acid, methacrylic acid, maleic acid, 2-vinylbenzoic acid, 2-vinylphenylacetic acid, 2-vinylbenzoic acid methyl methacrylate, sodium acrylate, sodium methacrylate, sodium maleate, potassium acrylate, potassium methacrylate, potassium maleate, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, butyl acrylate, and hydroxy-n-butyl methacrylate.

In step S01, the initiator is any one or a combination of two or more of hydrogen peroxide, ammonium persulfate, sodium persulfate, potassium persulfate, azobisisobutyronitrile, azobisisoheptonitrile, and diisopropyl peroxydicarbonate; the reducing agent is any one or the combination of more than two of L-ascorbic acid, sodium sulfite, sodium hypophosphite, sodium pyrosulfite and sodium bisulfite; the molecular weight regulator is one or the combination of more than two of thioglycolic acid, mercaptoethanol, 2-mercaptopropionic acid, 3-mercaptopropionic acid, sodium methyl propenyl sulfonate and dodecyl mercaptan.

In step S01, the initiator is any one or a combination of two or more of hydrogen peroxide, ammonium persulfate, sodium persulfate, potassium persulfate, azobisisobutyronitrile, azobisisoheptonitrile, and diisopropyl peroxydicarbonate; the reducing agent is any one or the combination of more than two of L-ascorbic acid, sodium sulfite, sodium hypophosphite, sodium pyrosulfite and sodium bisulfite; the molecular weight regulator is one or the combination of more than two of thioglycolic acid, mercaptoethanol, 2-mercaptopropionic acid, 3-mercaptopropionic acid, sodium methyl propenyl sulfonate and dodecyl mercaptan.

In step S02, the dihalobenzonitrile is any one or a combination of two or more of 2, 4-dichlorobenzonitrile, 2, 5-dichlorobenzonitrile, 2, 6-dichlorobenzonitrile, 3, 5-dibromobenzonitrile, 2, 6-dibromobenzonitrile, 2, 5-difluorobenzonitrile, 3, 5-difluorobenzonitrile, and 2, 6-difluorobenzonitrile.

In step S02, the acid-binding agent is any one or a combination of two or more of sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide, lithium hydroxide, silver hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, disodium bicarbonate, dipotassium bicarbonate, diethylamine, triethylamine, pyridine, 4-Dimethylaminopyridine (DMAP), N' -Dicyclohexylcarbodiimide (DCC), N-diisopropylethylamine, and quaternary ammonium base.

In step S02, the solvent is one or a combination of two or more of acetonitrile, methanol, ethanol, ethylene glycol, isopropanol, tert-butanol, acetone, Dichloromethane (DCM), chloroform, benzene, toluene, dimethyl sulfoxide (DMSO), N-Dimethylformamide (DMF), and 1, 2-dichloroethane.

In step S03, the structural formula of the terminal halogen-based polyethylene glycol monomethyl ether is:

wherein X is any one or the combination of more than two of chlorine, bromine, iodine or fluorine atoms; the polymerization degree p is 10 to 200.

Specific example 1:

example 1

1) 4-hydroxystyrene (1mol) and methacrylic acid (6mol) are subjected to aqueous solution free radical polymerization reaction for 3.5h under the combined action of hydrogen peroxide (0.1mol), sodium metabisulfite (0.15mol) and sodium methallyl sulfonate (0.1mol) at 35 ℃ to prepare a prepolymerization product A.

2) Reacting the prepolymerization product A obtained in the step 1) with 2, 6-dichlorobenzonitrile (4.2mol) and hydroquinone (4.2mol) under the action of 10mL of NMP and potassium carbonate (0.5mol), refluxing the reaction product A with sodium azide (4.5mol) in a mixed solution of 20mL of DMF and water at 100 ℃, and reacting for 5 hours under the catalytic action of ammonium chloride (0.5mol) to generate a prepolymer B containing tetrazole; the obtained product contains fourThe azole prepolymer B reacts with bromine-terminated polyethylene glycol monomethyl ether (4.5mol, Mw is 1500g/mol) for 2h to obtain the polycarboxylic acid water reducer (M) with the functions of reducing and resisting bacteria_w＝36000g/mol)。

The molecular structural formula is as follows:

wherein the polymerization degrees n, m, r and p are respectively 30, 5, 4 and 32.

Example 2

1) 4-hydroxystyrene (1mol) and acrylic acid (6mol) are subjected to aqueous solution free radical polymerization reaction for 4.5h under the combined action of ammonium persulfate (0.08mol), sodium bisulfite (0.15mol) and 2-mercaptopropionic acid (0.05mol) at 45 ℃ to prepare a prepolymer product A.

2) Reacting the prepolymer A obtained in the step 1) with 2, 4-dichlorobenzonitrile (5.2mol) and hydroquinone (5.2mol) under the action of 10mL of NMP and sodium carbonate (0.5mol), refluxing the prepolymer A with sodium azide (5.5mol) in a mixed solution of 20mL of acetone and water at 120 ℃, and reacting for 6h under the catalytic action of ammonium chloride (0.5mol) to generate a prepolymer B containing tetrazole; and (3) reacting the obtained prepolymer B containing tetrazole with terminal bromo polyethylene glycol monomethyl ether (5.5mol, Mw (equal to 800 g/mol)) for 2h to obtain the polycarboxylic acid water reducer with the reduction and antibacterial functions (Mw (equal to 42000 g/mol)).

The molecular structural formula is as follows:

wherein the polymerization degrees n, m, r and p are 48, 8, 5 and 16, respectively.

Example 3

1) 4- (4-vinyl benzene) phenol (1mol) and sodium methacrylate (5mol) are subjected to aqueous solution free radical polymerization reaction for 5h at 35 ℃ under the combined action of ammonium persulfate (0.1mol), sodium metabisulfite (0.15mol) and dodecanethiol (0.06mol) to prepare a prepolymerization product A.

2) Reacting the prepolymer A obtained in the step 1) with 2, 6-dichlorobenzonitrile (8.2mol) and hydroquinone (8.2mol) under the action of 10mL of NMP and sodium bicarbonate (0.5mol), refluxing the prepolymer A with sodium azide (8.5mol) in a mixed solution of 20mL of DMSO and water at 80 ℃, and reacting for 6h under the catalytic action of ammonium chloride (0.5mol) to generate a prepolymer B containing tetrazole; and (3) reacting the obtained prepolymer B containing tetrazole with fluorine-terminated polyethylene glycol monomethyl ether (8.5mol, Mw (equal to 500 g/mol)) for 1.5h to obtain the polycarboxylic acid water reducer with the reduction and antibacterial functions (Mw (equal to 50000 g/mol)).

The molecular structural formula is as follows:

wherein the polymerization degrees n, m, r and p are 42, 9, 8 and 9, respectively.

Example 4

1) 4-hydroxystyrene (1mol) and sodium acrylate (7mol) are subjected to aqueous solution free radical polymerization reaction for 4h at 50 ℃ under the combined action of hydrogen peroxide (0.1mol), L-ascorbic acid (0.05mol) and dodecyl mercaptan (0.06mol) to prepare a prepolymer A.

2) Reacting the prepolymer A obtained in the step 1) with 2, 5-dichlorobenzonitrile (3.2mol) and hydroquinone (3.2mol) under the action of 10mL of NMP and sodium bicarbonate (0.5mol), refluxing the prepolymer A with sodium azide (3.5mol) in a mixed solution of 20mL of DMF and water at 90 ℃, and reacting for 4 hours under the catalytic action of ammonium chloride (0.5mol) to generate a prepolymer B containing tetrazole; and (3) reacting the obtained prepolymer B containing tetrazole with chlorine-terminated polyethylene glycol monomethyl ether (3.5mol, Mw (2200 g/mol)) for 1.5h to obtain the polycarboxylic acid water reducer with the reduction and antibacterial functions (Mw (60000 g/mol)).

The molecular structural formula is as follows:

wherein the polymerization degrees n, m, q and p are 50, 7, 3 and 49, respectively.

Example 5

1) 4-hydroxystyrene (1mol), acrylic acid (3mol) and hydroxyethyl acrylate (3mol) are subjected to aqueous solution free radical polymerization reaction for 3.5h at 40 ℃ under the combined action of sodium persulfate (0.12mol), L-ascorbic acid (0.08mol) and 3-mercaptopropionic acid (0.06mol) to prepare a prepolymer A.

2) Reacting the prepolymer A obtained in the step 1) with 2, 6-dichlorobenzonitrile (3.2mol) and hydroquinone (3.2mol) under the action of 10mL of NMP and sodium hydroxide (0.5mol), refluxing the prepolymer A with sodium azide (3.5mol) in a mixed solution of 20mL of acetone and water at 110 ℃, and reacting for 4 hours under the catalytic action of zinc chloride (0.5mol) to generate a prepolymer B containing tetrazole; and (3) reacting the obtained prepolymer B containing tetrazole with iodine-terminated polyethylene glycol monomethyl ether (3.5mol, Mw (equal to 1000 g/mol)) for 2h to obtain the polycarboxylic acid water reducer with the reduction and antibacterial functions (Mw (equal to 40000 g/mol).

The molecular structural formula is as follows:

wherein the polymerization degrees n1, n2, m, r and p are 33, 33, 11, 3 and 17, respectively.

Example 6

1) 4- (4-vinyl benzene) phenol (1mol) and sodium acrylate (3.5mol) are subjected to aqueous solution free radical polymerization reaction for 5h at 45 ℃ under the combined action of hydrogen peroxide (0.1mol), sodium bisulfite (0.12mol) and mercaptoethanol (0.08mol) to prepare a prepolymerization product A.

2) Reacting the prepolymer A obtained in the step 1) with 2, 6-dichlorobenzonitrile (5.2mol) and 4,4' -biphenol (5.2mol) under the action of 10mL of NMP and sodium carbonate (0.5mol), refluxing the prepolymer A with sodium azide (5.5mol) in a mixed solution of 20mL of acetone and water at 100 ℃, and reacting for 4 hours under the catalytic action of zinc chloride (0.5mol) to generate a prepolymer B containing tetrazole; and (3) reacting the obtained prepolymer B containing tetrazole with iodine-terminated polyethylene glycol monomethyl ether (5.5mol, Mw (1500 g/mol)) for 2h to obtain the polycarboxylic acid water reducer with the reduction and antibacterial functions (Mw (55000 g/mol)).

The molecular structural formula is as follows:

wherein the polymerization degrees n, m, r and p are 22, 7, 5 and 28, respectively.

Example 7

1) Carrying out aqueous solution free radical polymerization reaction on 4-hydroxystyrene (0.5mol), 4- (4-vinyl benzene) phenol (0.5mol) and potassium acrylate (4.5mol) for 4.5h under the combined action of potassium persulfate (0.08mol), sodium bisulfite (0.12mol) and 3-mercaptopropionic acid (0.07mol) at 40 ℃ to prepare a prepolymerization product A;

2) reacting the prepolymerization product A obtained in the step 1) with 3, 5-dichlorobenzonitrile (6.2mol) and hydroquinone (6.2mol) under the action of 10mL of NMP and potassium carbonate (0.5mol), refluxing the reaction product A with sodium azide (6.5mol) in a mixed solution of 20mL of DMF and water at 100 ℃, and reacting for 4 hours under the catalytic action of zinc chloride (0.5mol) to generate a prepolymer B containing tetrazole; and (3) reacting the obtained prepolymer B containing tetrazole with iodine-terminated polyethylene glycol monomethyl ether (6.5mol, Mw (equal to 800 g/mol)) for 2h to obtain the polycarboxylic acid water reducer with the reduction and antibacterial functions (Mw (equal to 42000 g/mol)).

The molecular structural formula is as follows:

wherein the polymerization degrees n, m1, m2, r1, r2 and p are 65, 7, 7, 3, 3 and 12, respectively.

Example 8

1) Carrying out aqueous solution free radical polymerization reaction on 4-hydroxystyrene (1mol) and acrylic acid (4mol) for 4h under the combined action of hydrogen peroxide (0.1mol), sodium hypophosphite (0.11mol) and dodecyl mercaptan (0.08mol) at 35 ℃ to prepare a prepolymerization product A;

2) reacting the prepolymer A obtained in the step 1) with 2, 5-dichlorobenzonitrile (3.2mol), 2, 6-dichlorobenzonitrile (3.2mol) and 4,4' -biphenol (6.2mol) under the action of 10mL of NMP and sodium bicarbonate (0.5mol), refluxing the prepolymer A with sodium azide (6.5mol) in a mixed solution of 20mL of acetone and water at 100 ℃, and reacting for 4h under the catalytic action of zinc chloride (0.5mol) to generate a prepolymer B containing tetrazole; and (3) reacting the obtained prepolymer B containing tetrazole with fluorine-terminated polyethylene glycol monomethyl ether (6.5mol, Mw (1000 g/mol)) for 2h to obtain the polycarboxylic acid water reducer with the reduction and antibacterial functions (Mw (50000 g/mol)).

The molecular structural formula is as follows:

wherein the polymerization degrees n, m, r, q and p are 26, 7, 3, 3 and 21, respectively.

Comparative example 1

Mixing acrylic acid (5mol), allyl polyethylene glycol (1mol, M)_w1500g/mol) under the combined action of hydrogen peroxide (0.12mol), L-ascorbic acid (0.05mol) and 3-mercaptopropionic acid (0.04mol), aqueous solution free radical polymerization reaction is carried out for 5h at 35 ℃ to obtain the antibacterial polycarboxylic acid water reducing agent (M)_w＝38000g/mol)。

The molecular structural formula is as follows:

wherein the polymerization degrees n, m and p are 100, 20 and 33, respectively.

Comparative example 2

Mixing 5mol of potassium acrylate and 1mol of methyl allyl polyoxyethylene ether_w2200g/mol) under the combined action of ammonium persulfate (0.08mol), sodium bisulfite (0.1mol) and 2-mercaptopropionic acid (0.1mol), aqueous solution free radical polymerization is carried out for 5h at 30 ℃ to obtain the antibacterial polycarboxylic acid water reducing agent (M)_w＝35000g/mol)。

The molecular structural formula is as follows:

wherein the polymerization degrees n, m and p are 64, 13 and 49, respectively.

Test example

1. Cement paste fluidity test

The samples obtained in examples 1 to 8, comparative example 1 and comparative example 2 were tested for net slurry fluidity by reference to GB/T8077-. Wherein W/C is 0.29, the folded solid admixture amount of the admixture is 0.15 percent of the cement dosage, and the initial net slurry fluidity (after stirring is finished), the 1h net slurry fluidity and the 2h net slurry fluidity are respectively tested. As a result, it was found that: compared with the common polycarboxylic acid water reducing agent of the comparative example, the neat paste of all the examples has obvious improvement of the initial dispersion and dispersion maintaining effect, and basically has no fluidity loss within 4-5 hours after the stirring is finished.

TABLE 1 Net pulp fluidity and loss over time for different samples

2. Testing of concrete Properties

With reference to GB 8076-. The results show that: by comparing the concrete slump and the concrete expansion degree with different ages, the embodiment has more excellent dispersion and dispersion retention performance compared with the comparative example, and in addition, the 3d compressive strength of the concrete is improved by 9 percent on average, the 7d compressive strength is improved by 6 percent, the 28d compressive strength is improved by 7 percent, and the compressive strengths with different ages are obviously improved. In addition, compared with the concrete doped with the comparative example, the concrete doped with the example of the invention has obvious reduction of 28d shrinkage ratio, and can be reduced by 50 percent on average.

TABLE 2 concrete slump retaining and mechanical properties of different samples

3. Test of antibacterial Property

The samples obtained in examples 1 to 8, comparative example 1 and comparative example 2 were subjected to the measurement of the mildewproof bactericidal property with reference to JC/T2552-. In the test, distilled water was added to the additive until the solid content was diluted to 15%, then the same amount of microorganisms were injected to each group and stirred uniformly, and the mixture was cultured in an incubator at (30. + -. 2 ℃ C.) to observe whether mildew, hyphae or odor occurred, and the results are shown in Table 3.

As a result, it was found that: the polycarboxylate superplasticizer with the functions of shrinkage reduction and antibiosis has no phenomena of hypha and peculiar smell within 9 months, and compared with the ordinary polycarboxylate superplasticizer, the polycarboxylate superplasticizer has the phenomena of hypha and peculiar smell within 6 months. In example 2, example 3, example 5, example 6 and example 7, no mildew, hyphae or off-flavor appeared within 12 months. This means that the polycarboxylate superplasticizer with the functions of shrinkage reduction and antibiosis can have good inhibition effect on bacteria, microorganisms and the like.

TABLE 3 antimicrobial Properties of different samples

Although the present invention has been described with reference to the preferred embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.