Multi-arm polycarboxylate water reducer and preparation method thereof

Abstract

The present invention discloses a multi-arm polycarboxylate water reducer and a preparation method thereof, the preparation method includes the following steps: making a phenolic hydroxyl containing rigid compound and p-nitrobenzonitrile subjected to a nucleophilic substitution reaction in a solvent, then subjected to addition with a sodium azide in a solvent and water mixed solution to obtain a tetrazole derivative; making an unsaturated polyether macromonomer subjected to terminal halogenation and react with the prepared tetrazole derivative to obtain a tetrazole-containing multi-arm unsaturated polyether macromonomer; and subjecting the tetrazole-containing multi-arm unsaturated polyether macromonomer, an unsaturated carboxylic acid small monomer and an unsaturated polyether macromonomer to a free radical polymerization reaction under combined action of an initiator, a reducing agent and a molecular weight regulator to obtain the multi-arm polycarboxylate water reducer integrating shrinkage reducing and antibacterial functions.

Claims

1. A multi-arm polycarboxylate water reducer, having the following structure: ##STR00017## wherein polymerization degrees p, n, m and r are each independently 1 to 100; the number q of branches is 2 to 6; M is one or a combination of two or more of ##STR00018## ##STR00019## R.sub.1 and R.sub.6 are both one or a combination of two or more of —CH.sub.2—, —CH.sub.2CH.sub.2—, —CH.sub.2CH.sub.2O— or —CH.sub.2CH.sub.2CH.sub.2CH.sub.2O—; R.sub.2 and R.sub.4 are both one or a combination of two of H or —CH.sub.3; R.sub.3 is one or a combination of two or more of H, —COOH, —CH.sub.3, —CH.sub.2CH.sub.3, a phenyl or a phenyl derivative; and R.sub.5 is one or a combination of two or more of H, an alkali metal ion, an alkyl containing 1 to 6 carbon atoms, a hydroxyalkyl containing 1 to 6 carbon atoms, an alkoxy containing 1 to 6 carbon atoms, a phenyl or a phenyl derivative.

2. A preparation method of a multi-arm polycarboxylate water reducer, used for preparing the multi-arm polycarboxylate water reducer according to claim 1, comprising the following steps: Step 1: preparation of a tetrazole derivative: subjecting a phenolic hydroxyl containing rigid compound and p-nitrobenzonitrile to a nucleophilic substitution reaction in a solvent, then subjecting a reaction product and a sodium azide to reflux in a solvent and water mixed solution, and conducting a 1,3-dipolar cycloaddition reaction for 3 hours to 10 hours under action of a catalyst to obtain the tetrazole derivative; Step 2: preparation of a tetrazole-containing multi-arm unsaturated polyether macromonomer: making an unsaturated polyether macromonomer subjected to terminal halogenation with epoxy halogenated propane under action of boron trifluoride diethyl etherate, then react with the tetrazole derivative prepared in Step 1 for 3 hours to 10 hours to obtain the tetrazole-containing multi-arm unsaturated polyether macromonomer; and Step 3: preparation of a multi-arm polycarboxylate water reducer integrating shrinkage reducing and antibacterial functions: subjecting the tetrazole-containing multi-arm unsaturated polyether macromonomer prepared in Step 2, an unsaturated carboxylic acid small monomer and an unsaturated polyether macromonomer to a free radical polymerization reaction for 3 hours to 5 hours at 10° C. to 50° C. under combined action of an initiator, a reducing agent and a molecular weight regulator to obtain the multi-arm polycarboxylate water reducer integrating the shrinkage reducing and antibacterial functions, wherein a molar ratio of the tetrazole-containing multi-arm unsaturated polyether macromonomer, the unsaturated carboxylic acid small monomer, the unsaturated polyether macromonomer, the initiator, the reducing agent and the molecular weight regulator is 1: (2 to 80): (1 to 20): (0.02 to 0.2): (0.02 to 0.25): (0.02 to 0.2).

3. The preparation method of the multi-arm polycarboxylate water reducer according to claim 2, wherein in Step 1, the phenolic hydroxyl containing rigid compound is any one or a combination of two or more of 4,4′-dihydroxybiphenyl, 4,4′,4″-methylenetriphenol, 1,1,1-tris(4-hydroxyphenyl)ethane, 1,3,5-tris(4-hydroxyphenyl)benzene, 1,1,2,2-tetrakis(4-hydroxyphenyl)ethane, 2,3′,4,5′,6-pentahydroxybiphenyl, hexahydroxybenzene, 5-(3,4,5-trihydroxyphenyl)benzene-1,2,3-triol or 4-[2,3,4,5,6-penta(4-hydroxyphenyl)phenyl]phenol.

4. The preparation method of the multi-arm polycarboxylate water reducer according to claim 2, wherein in Step 1, the solvent is any one or a combination of two or more of acetonitrile, methanol, ethanol, ethylene glycol, isopropanol, tert-butanol, acetone, dichloromethane, chloroform, benzene, toluene, dimethyl sulfoxide, N,N-dimethylformamide, and 1,2-dichloroethane.

5. The preparation method of the multi-arm polycarboxylate water reducer according to claim 2, wherein the catalyst is any one or a combination of two or more of ammonium chloride, zinc chloride, aluminum chloride or ferric chloride.

6. The preparation method of the multi-arm polycarboxylate water reducer according to claim 2, wherein the unsaturated polyether macromonomer is any one or a combination of two or more of allyl polyoxyethylene ether, methallyl polyoxyethylene ether, isopentenol polyoxyethylene ether, vinyl polyoxyethylene ether or 4-hydroxybutyl vinyl polyoxyethylene ether.

7. The preparation method of the multi-arm polycarboxylate water reducer according to claim 2, wherein in Step 2, the epoxy halogenated propane is any one or a combination of two or more of epifluorohydrin, epichlorohydrin or epiboromohydrin.

8. The preparation method of the multi-arm polycarboxylate water reducer according to claim 2, wherein in Step 3, the unsaturated carboxylic acid small monomer is any one or a combination of two or more of acrylic acid, methacrylic acid, maleic acid, sodium acrylate, sodium methacrylate, sodium maleate, potassium acrylate, potassium methacrylate, potassium maleate, 2-vinylbenzoic acid, 2-vinylphenylacetic acid, 2-methyl vinyl benzoate acrylic acid, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, butyl acrylate, and hydroxy n-butyl methacrylate.

9. The preparation method of the multi-arm polycarboxylate water reducer according to claim 2, wherein in Step 3, the initiator is any one or a combination of two or more of hydrogen peroxide, ammonium persulfate, sodium persulfate, potassium persulfate, azobisisobutyronitrile or azobisisoheptanenitrile; the reducing agent is any one or a combination of two or more of vitamin C, sodium sulfite, sodium bisulfite, sodium metabisulfite, or sodium hypophosphite; and the molecular weight regulator is any one or a combination of two or more of mercaptoethanol, mercaptoacetic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, dodecanethiol, or sodium methyl propenyl sulfonate.

Description

DETAILED DESCRIPTION OF EMBODIMENTS

(1) A multi-arm polycarboxylate water reducer, having the following structure:

(2) wherein polymerization degrees p, n, m and r are each independently 1 to 100; the number q of branches is 2 to 6.

(3) ##STR00004##

(4) M is one or a combination of two or more of

(5) ##STR00005## ##STR00006##

(6) R.sub.1 and R.sub.6 are both one or a combination of two or more of —CH.sub.2—, —CH.sub.2CH.sub.2—, —CH.sub.2CH.sub.2O— or —CH.sub.2CH.sub.2CH.sub.2CH.sub.2O—; R.sub.2 and R.sub.4 are both one or a combination of two of H or —CH.sub.3; R.sub.3 is one or a combination of two or more of H, —COOH, —CH.sub.3, —CH.sub.2CH.sub.3, a phenyl or a phenyl derivative; and R.sub.5 is one or a combination of two or more of H, an alkali metal ion, an alkyl containing 1 to 6 carbon atoms, a hydroxyalkyl containing 1 to 6 carbon atoms, an alkoxy containing 1 to 6 carbon atoms, a phenyl or a phenyl derivative.

(7) A preparation method of a multi-arm polycarboxylate water reducer, including the following steps:

(8) Step 1: preparation of a tetrazole derivative: subjecting a phenolic hydroxyl containing rigid compound and p-nitrobenzonitrile to a nucleophilic substitution reaction in a solvent, then subjecting a reaction product and a sodium azide to reflux in a solvent and water mixed solution, and conducting a 1,3-dipolar cycloaddition reaction for 3 hours to 10 hours under action of a catalyst to obtain the tetrazole derivative.

(9) Step 2: preparation of a tetrazole-containing multi-arm unsaturated polyether macromonomer: making an unsaturated polyether macromonomer subjected to terminal halogenation with epoxy halogenated propane under action of boron trifluoride diethyl etherate, then react with the tetrazole derivative prepared in Step 1 for 3 hours to 10 hours to obtain the tetrazole-containing multi-arm unsaturated polyether macromonomer.

(10) Step 3: preparation of a multi-arm polycarboxylate water reducer integrating shrinkage reducing and antibacterial functions: subjecting the tetrazole-containing multi-arm unsaturated polyether macromonomer prepared in Step 2, an unsaturated carboxylic acid small monomer and an unsaturated polyether macromonomer to a free radical polymerization reaction for 3 hours to 5 hours at 10° C. to 50° C. under combined action of an initiator, a reducing agent and a molecular weight regulator to obtain the multi-arm polycarboxylate water reducer integrating the shrinkage reducing and antibacterial functions, wherein a molar ratio of the tetrazole-containing multi-arm unsaturated polyether macromonomer, the unsaturated carboxylic acid small monomer, the unsaturated polyether macromonomer, the initiator, the reducing agent and the molecular weight regulator is 1: (2 to 80): (1 to 20): (0.02 to 0.2): (0.02 to 0.25): (0.02 to 0.2).

(11) Further, in Step 1, the phenolic hydroxyl containing rigid compound is any one or a combination of two or more of 4,4′-dihydroxybiphenyl, 4,4′,4″-methylenetriphenol, 1,1,1-tris(4-hydroxyphenyl)ethane, 1,3,5-tris(4-hydroxyphenyl)benzene, 1,1,2,2-tetrakis(4-hydroxyphenyl)ethane, 2,3′,4,5′,6-pentahydroxybiphenyl, hexahydroxybenzene, 5-(3,4,5-trihydroxyphenyl)benzene-1,2,3-triol or 4-[2,3,4,5,6-penta(4-hydroxyphenyl)phenyl]phenol.

(12) Further, in Step 1, the solvent is any one or a combination of two or more of acetonitrile, methanol, ethanol, ethylene glycol, isopropanol, tert-butanol, acetone, dichloromethane, chloroform, benzene, toluene, dimethyl sulfoxide, N,N-dimethylformamide, and 1,2-dichloroethane.

(13) Further, the catalyst is any one or a combination of two or more of ammonium chloride, zinc chloride, aluminum chloride or ferric chloride.

(14) Further, the unsaturated polyether macromonomer is any one or a combination of two or more of allyl polyoxyethylene ether, methallyl polyoxyethylene ether, isopentenol polyoxyethylene ether, vinyl polyoxyethylene ether or 4-hydroxybutyl vinyl polyoxyethylene ether.

(15) Further, in Step 2, the epoxy halogenated propane is any one or a combination of two or more of epifluorohydrin, epichlorohydrin or epiboromohydrin.

(16) Further, in Step 3, the unsaturated carboxylic acid small monomer is any one or a combination of two or more of acrylic acid, methacrylic acid, maleic acid, sodium acrylate, sodium methacrylate, sodium maleate, potassium acrylate, potassium methacrylate, potassium maleate, 2-vinylbenzoic acid, 2-vinylphenylacetic acid, 2-methyl vinyl benzoate acrylic acid, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, butyl acrylate, and hydroxy n-butyl methacrylate.

(17) Further, in Step 3, the initiator is any one or a combination of two or more of hydrogen peroxide, ammonium persulfate, sodium persulfate, potassium persulfate, azobisisobutyronitrile or azobisisoheptanenitrile; the reducing agent is any one or a combination of two or more of vitamin C, sodium sulfite, sodium bisulfite, sodium metabisulfite, or sodium hypophosphite; and the molecular weight regulator is any one or a combination of two or more of mercaptoethanol, mercaptoacetic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, dodecanethiol, or sodium methyl propenyl sulfonate.

SPECIFIC EXAMPLES

Example 1

(18) 1) 4,4′,4″-Methylenetriphenol (1.2 mol) and p-nitrobenzonitrile (3.5 mol) were subjected to a nucleophilic substitution reaction in DMF (30 mL). Then a reaction product and a sodium azide (3.5 mol) were subjected to reflux in a DMF and water mixed solution. A 1,3-dipolar cycloaddition reaction was conducted for 5 hours under action of catalysis of ammonium chloride (0.2 mol) to obtain a tetrazole derivative. 2) Allyl polyoxyethylene ether (3.5 mol, M.sub.w=1,500 g/mol) was subjected to terminal halogenation with epichlorohydrin (3.8 mol) under action of boron trifluoride diethyl etherate (0.2 mol), and then reacted with the tetrazole derivative (1.1 mol) for 4 hours to obtain a tetrazole-containing multi-arm unsaturated polyether macromonomer. 3) The tetrazole-containing multi-arm unsaturated polyether macromonomer (1 mol), acrylic acid (50 mol) and allyl polyoxyethylene ether (9 mol, M.sub.w=1,500 g/mol) were subjected to a free radical polymerization reaction for 3.5 hours at 30° C. under combined action of hydrogen peroxide (0.1 mol), vitamin C (0.08 mol) and mercaptoethanol (0.08 mol) to obtain a multi-arm polycarboxylate water reducer (M.sub.w=25,000 g/mol) integrating shrinkage reducing and antibacterial functions.

(19) A molecular structural formula is as follows:

(20) ##STR00007##

(21) wherein polymerization degrees p, n, m and r are 33, 17, 3 and 33, respectively.

Example 2

(22) 1) 1,3,5-Tris(4-hydroxyphenyl)benzene (1.2 mol) and p-nitrobenzonitrile (3.5 mol) were subjected to a nucleophilic substitution reaction in DCM (30 mL). Then a reaction product and a sodium azide (3.5 mol) were subjected to reflux in a DCM and water mixed solution. A 1,3-dipolar cycloaddition reaction was conducted for 8 hours under action of catalysis of ammonium chloride (0.2 mol) to obtain a tetrazole derivative. 2) Isopentenol polyoxyethylene ether (3.5 mol, M.sub.w=2,200 g/mol) was subjected to terminal halogenation with epiboromohydrin (3.8 mol) under action of boron trifluoride diethyl etherate (0.2 mol), and then reacted with the tetrazole derivative (1.1 mol) for 5 hours to obtain a tetrazole-containing multi-arm unsaturated polyether macromonomer. 3) The tetrazole-containing multi-arm unsaturated polyether macromonomer (1 mol), methacrylic acid (45 mol) and isopentenol polyoxyethylene ether (12 mol, M.sub.w=2,200 g/mol) were subjected to a free radical polymerization reaction for 5 hours at 35° C. under combined action of ammonium persulfate (0.1 mol), sodium bisulfite (0.15 mol) and dodecanethiol (0.06 mol) to obtain a multi-arm polycarboxylate water reducer (M.sub.w=35,000 g/mol) integrating shrinkage reducing and antibacterial functions.

(23) A molecular structural formula is as follows:

(24) ##STR00008##

(25) wherein polymerization degrees p, n, m and r are 48, 12, 4 and 48, respectively.

Example 3

(26) 1) 1,1,2,2-tetrakis(4-hydroxyphenyl)ethane(1.2 mol) and p-nitrobenzonitrile (4.5 mol) were subjected to a nucleophilic substitution reaction in DMSO (30 mL). Then a reaction product and a sodium azide (4.5 mol) were subjected to reflux in a DMSO and water mixed solution. A 1,3-dipolar cycloaddition reaction was conducted for 6 hours under action of catalysis of zinc chloride (0.2 mol) to obtain a tetrazole derivative. 2) Isopentenol polyoxyethylene ether (4.5 mol, M.sub.w=2,900 g/mol) was subjected to terminal halogenation with epichlorohydrin (4.8 mol) under action of boron trifluoride diethyl etherate (0.2 mol), and then reacted with the tetrazole derivative (1.1 mol) for 6 hours to obtain a tetrazole-containing multi-arm unsaturated polyether macromonomer. 3) The tetrazole-containing multi-arm unsaturated polyether macromonomer (1 mol), sodium acrylate (40 mol) and isopentenol polyoxyethylene ether (8 mol, M.sub.w=2,900 g/mol) were subjected to a free radical polymerization reaction for 3.5 hours at 40° C. under combined action of potassium persulfate (0.09 mol), sodium metabisulfite (0.15 mol) and 3-mercaptopropionic acid (0.08 mol) to obtain a multi-arm polycarboxylate water reducer (M.sub.w=40,000 g/mol) integrating shrinkage reducing and antibacterial functions.

(27) A molecular structural formula is as follows:

(28) ##STR00009##

(29) wherein polymerization degrees p, n, m and r are 64, 4, 2 and 64, respectively.

Example 4

(30) 1) Hexahydroxybenzene (1.2 mol) and p-nitrobenzonitrile (6.5 mol) were subjected to a nucleophilic substitution reaction in DMF (30 mL). Then a reaction product and a sodium azide (6.5 mol) were subjected to reflux in a DMF and water mixed solution. A 1,3-dipolar cycloaddition reaction was conducted for 7 hours under action of catalysis of ferric chloride (0.2 mol) to obtain a tetrazole derivative. 2) Isopentenol polyoxyethylene ether (6.5 mol, M.sub.w=1,500 g/mol) was subjected to terminal halogenation with epichlorohydrin (6.8 mol) under action of boron trifluoride diethyl etherate (0.2 mol), and then reacted with the tetrazole derivative (1.1 mol) for 5 hours to obtain a tetrazole-containing multi-arm unsaturated polyether macromonomer. 3) The tetrazole-containing multi-arm unsaturated polyether macromonomer (1 mol), potassium acrylate (60 mol) and isopentenol polyoxyethylene ether (12 mol, M.sub.w=500 g/mol) were subjected to a free radical polymerization reaction for 3.5 hours at 25° C. under combined action of hydrogen peroxide (0.11 mol), sodium bisulfite (0.15 mol) and 3-mercaptopropionic acid (0.06 mol) to obtain a multi-arm polycarboxylate water reducer (M.sub.w=60,000 g/mol) integrating shrinkage reducing and antibacterial functions.

(31) A molecular structural formula is as follows:

(32) ##STR00010##

(33) wherein polymerization degrees p, n, m and r are 33, 10, 2 and 33, respectively.

Example 5

(34) 1) 1,1,1-Tris(4-hydroxyphenyl)ethane (1.2 mol) and p-nitrobenzonitrile (3.5 mol) were subjected to a nucleophilic substitution reaction in acetone (30 mL). Then a reaction product and a sodium azide (3.5 mol) were subjected to reflux in an acetone and water mixed solution. A 1,3-dipolar cycloaddition reaction was conducted for 6.5 hours under action of catalysis of zinc chloride (0.2 mol) to obtain a tetrazole derivative. 2) Methallyl polyoxyethylene ether (3.5 mol, M.sub.w=2,900 g/mol) was subjected to terminal halogenation with epifluorohydrin (3.8 mol) under action of boron trifluoride diethyl etherate (0.2 mol), and then reacted with the tetrazole derivative (1.1 mol) for 7 hours to obtain a tetrazole-containing multi-arm unsaturated polyether macromonomer. 3) The tetrazole-containing multi-arm unsaturated polyether macromonomer (1 mol), methacrylic acid (40 mol) and methallyl polyoxyethylene ether (12 mol, M.sub.w=2,900 g/mol) were subjected to a free radical polymerization reaction for 5 hours at 30° C. under combined action of ammonium persulfate (0.08 mol), vitamin C (0.07 mol) and 2-mercaptopropionic acid (0.05 mol) to obtain a multi-arm polycarboxylate water reducer (M.sub.w=48,000 g/mol) integrating shrinkage reducing and antibacterial functions.

(35) A molecular structural formula is as follows:

(36) ##STR00011##

(37) wherein polymerization degrees p, n, m and r are 65, 13, 4 and 65, respectively.

Example 6

(38) 1) 4,4′,4″-Methylenetriphenol (1.2 mol) and p-nitrobenzonitrile (3.5 mol) were subjected to a nucleophilic substitution reaction in DCM (30 mL). Then a reaction product and a sodium azide (3.5 mol) were subjected to reflux in a DCM and water mixed solution. A 1,3-dipolar cycloaddition reaction was conducted for 8 hours under action of catalysis of ammonium chloride (0.2 mol) to obtain a tetrazole derivative. 2) Vinyl polyoxyethylene ether (3.5 mol, M.sub.w=1,500 g/mol) was subjected to terminal halogenation with epichlorohydrin (3.8 mol) under action of boron trifluoride diethyl etherate (0.2 mol), and then reacted with the tetrazole derivative (1.1 mol) for 6 hours to obtain a tetrazole-containing multi-arm unsaturated polyether macromonomer. 3) The tetrazole-containing multi-arm unsaturated polyether macromonomer (1 mol), methacrylic acid (30 mol) and vinyl polyoxyethylene ether (12 mol, M.sub.w=1,500 g/mol) were subjected to a free radical polymerization reaction for 4 hours at 25° C. under combined action of sodium persulfate (0.12 mol), sodium bisulfite (0.14 mol) and mercaptoethanol (0.07 mol) to obtain a multi-arm polycarboxylate water reducer (M.sub.w=26,000 g/mol) integrating shrinkage reducing and antibacterial functions.

(39) A molecular structural formula is as follows:

(40) ##STR00012##

(41) wherein polymerization degrees p, n, m and r are 32, 10, 3 and 32, respectively.

Example 7

(42) 1) 1,1,2,2-Tetrakis(4-hydroxyphenyl)ethane (1.2 mol) and p-nitrobenzonitrile (3.5 mol) were subjected to a nucleophilic substitution reaction in DMSO (30 mL). Then a reaction product and a sodium azide (4.5 mol) were subjected to reflux in a DMSO and water mixed solution. A 1,3-dipolar cycloaddition reaction was conducted for 7 hours under action of catalysis of zinc chloride (0.2 mol) to obtain a tetrazole derivative. 2) Isopentenol polyoxyethylene ether (4.5 mol, M.sub.w=2,000 g/mol) was subjected to terminal halogenation with epiboromohydrin (4.8 mol) under action of boron trifluoride diethyl etherate (0.2 mol), and then reacted with the tetrazole derivative (1.1 mol) for 4 hours to obtain a tetrazole-containing multi-arm unsaturated polyether macromonomer. 3) The tetrazole-containing multi-arm unsaturated polyether macromonomer (1 mol), potassium methacrylate (60 mol) and isopentenol polyoxyethylene ether (8 mol, M.sub.w=2,000 g/mol) were subjected to a free radical polymerization reaction for 4 hours at 25° C. under combined action of hydrogen peroxide (0.1 mol), sodium hypophosphite (0.13 mol) and dodecanethiol (0.09 mol) to obtain a multi-arm polycarboxylate water reducer (M.sub.w=32,000 g/mol) integrating shrinkage reducing and antibacterial functions.

(43) A molecular structural formula is as follows:

(44) ##STR00013##

(45) wherein polymerization degrees p, n, m and r are 44, 15, 2 and 44, respectively.

Example 8

(46) 1) 1,3,5-Tris(4-hydroxyphenyl)benzene (1.2 mol) and p-nitrobenzonitrile (3.5 mol) were subjected to a nucleophilic substitution reaction in acetone (30 mL). Then a reaction product and a sodium azide (3.5 mol) were subjected to reflux in an acetone and water mixed solution. A 1,3-dipolar cycloaddition reaction was conducted for 7 hours under action of catalysis of ammonium chloride (0.2 mol) to obtain a tetrazole derivative. 2) Isopentenol polyoxyethylene ether (3.5 mol, M.sub.w=3,000 g/mol) was subjected to terminal halogenation with epichlorohydrin (3.8 mol) under action of boron trifluoride diethyl etherate (0.2 mol), and then reacted with the tetrazole derivative (1.1 mol) for 6 hours to obtain a tetrazole-containing multi-arm unsaturated polyether macromonomer. 3) The tetrazole-containing multi-arm unsaturated polyether macromonomer (1 mol), sodium acrylate (45 mol) and isopentenol polyoxyethylene ether (9 mol, M.sub.w=3,000 g/mol) were subjected to a free radical polymerization reaction for 4.5 hours at 35° C. under combined action of ammonium persulfate (0.1 mol), vitamin C (0.07 mol) and 3-mercaptopropionic acid (0.06 mol) to obtain a multi-arm polycarboxylate water reducer (M.sub.w=40,000 g/mol) integrating shrinkage reducing and antibacterial functions.

(47) A molecular structural formula is as follows:

(48) ##STR00014##

(49) wherein polymerization degrees p, n, m and r are 67, 15, 3 and 67, respectively.

Comparative Example 1

(50) Acrylic acid (5 mol) and allyl polyethylene glycol (1 mol, M.sub.w=1,500 g/mol) were subjected to an aqueous solution free radical polymerization reaction for 5 hours at 35° C. under combined action of hydrogen peroxide (0.12 mol), L-ascorbic acid (0.05 mol) and 3-mercaptopropionic acid (0.04 mol) to obtain an antibacterial polycarboxylate water reducer (M.sub.w=38,000 g/mol).

(51) A molecular structural formula is as follows:

(52) ##STR00015##

(53) wherein polymerization degrees n, m and p are 100, 20, and 33, respectively.

Comparative Example 2

(54) Potassium acrylate (5 mol) and methallyl polyoxyethylene ether (1 mol, M.sub.w=2,200 g/mol) were subjected to an aqueous solution free radical polymerization reaction for 5 hours at 30° C. under combined action of ammonium persulfate (0.08 mol), sodium bisulfite (0.1 mol) and 2-mercaptopropionic acid (0.1 mol) to obtain an antibacterial polycarboxylate water reducer (M.sub.w=35,000 g/mol).

(55) A molecular structural formula is as follows:

(56) ##STR00016##

(57) wherein polymerization degrees n, m and p are 64, 13, and 49, respectively.

Test Example

(58) 1. Test of neat cement paste fluidity

(59) Referring to GB/T 8077-2012 “Methods for Testing Uniformity of Concrete Admixture”, samples obtained in Examples 1 to 8, Comparative Example 1 and Comparative Example 2 were subjected to a neat paste fluidity test. Results were shown in Table 1. Among them, W/C was 0.29, and a solid content of an admixture was 0.15% of the amount of use of cement. Initial neat paste fluidity (after stirring was completed), 1-hour neat paste fluidity and 2-hour neat paste fluidity were tested respectively. The results showed that compared with traditional polycarboxylate water reducers, in all examples, the tested gradual fluidity of neat paste was significantly improved. In addition, it could be found that there was no loss of fluidity basically within 4 hours to 5 hours after stirring was completed.

(60) TABLE-US-00001 TABLE 1 Neat paste fluidity and gradual loss of different samples Neat paste fluidity (mm) Sample Content Initial 30 min 60 min Example 1 0.12% 238 234 229 Example 2 242 235 226 Example 3 237 232 227 Example 4 240 235 221 Example 5 238 232 225 Example 6 239 232 228 Example 7 242 237 232 Example 8 239 235 228 Comparative 230 227 220 Example 1 Comparative 228 226 217 Example 2 2. Performance test of concrete

(61) Referring to GB 8076-2008 “Concrete Admixtures”, samples obtained in Examples 1 to 8, Comparative Example 1 and Comparative Example 2 were subjected to determination of initial slump/extension of concrete, 1-hour gradual loss of slump/extension and strength of concrete specimens. A solid content of an admixture was 0.2% of the amount of use of glue. Specific results were shown in Table 2. The results showed that the examples had higher concrete slump and extension than the comparative examples, and showed more excellent dispersion and dispersion retention performance. In addition, it could be also found that compared with the comparative examples, in the examples, 3-d compressive strength of concrete could be increased maximum by 2.9 MPa, 7-d compressive strength could be increased maximum by 2.8 MPa, and 28-d compressive strength could be increased maximum by 3 MPa. In addition, compared with the concrete mixed with the comparative examples, the concrete mixed with the examples of the present invention had an obvious reduction in a 28-d shrinkage ratio, which could be reduced maximum by 48%.

(62) TABLE-US-00002 TABLE 2 Concrete slump retention and mechanical properties of different samples Slump/Extension Compressive 28-d (mm) strength/MPa shrinkage Sample Content Initial 1 h 3 d 7 d 28 d ratio/% Example 0.2% 220/510 190/480 24.3 33.4 37.7 39 1 Example 215/500 185/470 25.4 34.2 36.5 41 2 Example 210/520 190/480 25.2 34.5 37.9 37 3 Example 215/510 190/490 22.4 33.9 37.6 41 4 Example 220/510 195/490 24.3 32.7 38.1 41 5 Example 215/520 200/480 23.9 32.8 37.6 62 6 Example 215/510 195/490 25.4 33.9 38.5 36 7 Example 200/490 185/480 23.4 34.0 38.8 38 8 Compar- 200/490 180/460 22.3 32.3 35.5 84 ative Example 1 Compar- 205/480 185/460 22.6 32.7 35.8 83 ative Example 2 3. Antibacterial performance test

(63) Referring to JC/T 2552-2019 “Bactericide for Concrete Admixtures”, samples obtained in Examples 1 to 8, Comparative Example 1 and Comparative Example 2 were subjected to determination of anti-mold and bactericidal properties. In the test, distilled water was added to an admixture until its solid content is diluted to 15%, then the same amount of microorganisms was injected into each group and stirred evenly, placed in a 30±2° C. incubator for cultivation. Whether there were phenomena of mildew, mycelium or odor was observed. Results were shown in Table 3.

(64) The results showed that for all common polycarboxylate water reducers in the comparative examples, mycelium and odor appeared within 6 months; for Example 6 and Example 8, mycelium and odor appeared after 9 months; and for other examples, mycelium and odor did not appear within 12 months. This also meant that the multi-arm polycarboxylate water reducer integrating shrinkage reducing and antibacterial functions could itself have a good inhibitory effect on bacteria, microorganisms and the like.

(65) TABLE-US-00003 TABLE 3 Antibacterial properties of different samples Antibacterial properties (whether there are phenomena of mildew, mycelium or odor) Sample 3 months 6 months 9 months 12 months Example 1 × × × × Example 2 × × × × Example 3 × × × × Example 4 × × × × Example 5 × × × × Example 6 × × × ✓ Example 7 × × × × Example 8 × × × ✓ Comparative ✓ ✓ ✓ ✓ Example 1 Comparative × ✓ ✓ ✓ Example 2

(66) Although the present invention has been disclosed above with preferred examples, they are not intended to limit the present invention. Anyone skilled in the art can make various changes or modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be defined by the protection scope of the claims of the present application.