Concrete admixture as well as preparation method and application thereof

Abstract

The invention provides a concrete admixture which is a copolymer of a monomer I, a monomer II and an acrylic acid monomer, and the acrylic acid monomer is selected from a structure as shown in a formula III, and ester, salt or anhydride of the acrylic acid monomer. The monomer II of the admixture is stable in raw material source, low in price and high in double bond content; the raw material proportion can be adjusted according to actual product requirements, the preparation operation is simple, conditions are easy to control, the preparation method is environment-friendly, no industrial three wastes are generated, and the method is suitable for industrial large-scale production. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to the technical field of concrete, and in particular to a concrete admixture and a preparation method and application thereof. Background Art

[0002] As an important component of modern concrete, polycarboxylic acid water reducer has been widely used in the field of concrete engineering technology due to its excellent advantages of low dosage, high water reduction, high slump retention, and large freedom of molecular design. The currently widely used polycarboxylic acid water reducer is mainly based on water-reducing mother liquor, and is compounded with a certain proportion of slump retention mother liquor, as well as other small amounts of retarders, air entraining agents, defoamers, etc. With the widespread use of machine-made sand, the stone powder content in machine-made sand has increased. In some places, stone powder is used as a grading regulator, resulting in a high content of stone powder in concrete. The mixed concrete becomes sticky, the fluidity deteriorates, and the loss increases. Sometimes the pumping pipeline is blocked during the pumping process, which has a great impact on the construction. During construction, concrete is required to have low viscosity, good fluidity, and easy construction and pumping, but the existing admixtures cannot meet the above requirements. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a polymer, which is a copolymer of the following monomer I, monomer II and acrylic monomer:

[0004]

[0005] In monomer I, m is a number from 1 to 50, n is 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10; A is selected from C which is unsubstituted or optionally substituted by one, two or more Ra. 2-10 Alkylene; Ra is selected from halogen, C 1-12 Alkyl, halogenated C 1-12 Alkyl or C 1-12 Alkoxy;

[0006] In monomer II, p and q are the same or different and are independently 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10; R is C 4-20 branched saturated hydrocarbon group; x is a number from 0.1 to 20; y is a number from 0.5 to 50; R2 is selected from H or C 1-12 Alkyl; Q is C 1-10 Alkylene, CO or C 6-14 Aryl; E is C 2-12 Alkylene; R1 is selected from a hydrogen atom or an ionic hydrophilic group;

[0007] The acrylic monomer is selected from the structure shown in Formula III below, its ester, salt or anhydride;

[0008]

[0009] In formula III, R3 is selected from H or C 1-12 alkyl; R4 is selected from H, COOH, C 1-12 alkyl or -C 1-12 alkyl COOH.

[0010] According to an embodiment of the present invention, the molar ratio of monomer I, acrylic monomer and monomer II in the polymer is 1:1 - 10:0.1 - 1, for example 1:2 - 8:0.2 - 0.8, such as 1:3 - 7:0.3 - 0.7; such as 1:4 - 6:0.4 - 0.6.

[0011] According to an embodiment of the present invention, the number of moles of monomer I in the polymer is 2 - 20, for example 2 - 15, such as 3 - 10.

[0012] According to an embodiment of the present invention, in monomer I, A is selected from the following groups which are unsubstituted or optionally substituted by C 1-6 alkyl: C 2-10 alkylene, for example A is selected from (CH2)2, (CH2)3, CH(CH3)-CH2, (CH2)4, (CH2)5, (CH2)6, (CH2)7, (CH2)8, (CH2)9, (CH2) 10 , [CH(CH3)]2; n is selected from 1, 2, 3, 4 or 5; m is a number from 5 - 35;

[0013] In monomer II, p and q are the same or different and are independently 0, 1, 2 or 3; R is a branched-chain saturated hydrocarbon group of C 5-15 ; x is a number from 0.5 - 10, y is a number from 3 - 30; Q is methylene, CO or phenylene; E is C 2-6 alkylene; R1 is selected from H, -SO3M, -COOM, -PO3M2 or -HPO3M; where M is selected from hydrogen ion, alkali metal ion, alkaline earth metal ion, ammonium ion (NH4 + ), quaternary ammonium cation (such as the quaternary ammonium cation of alkylamine or alkylolamine), R1 is preferably -SO3M; R2 is H or C 1-6 alkyl.

[0014] In formula III, R3 is selected from H or C 1-6 alkyl; R4 is selected from H, COOH, C 1-6 alkyl or -C 1-6 alkyl COOH.

[0015] According to an embodiment of the present invention, in monomer I, A is selected from CH(CH3)-CH2, (CH2)2 or (CH2)3, n is selected from 1, 2 or 3; m is a number from 5 - 20;

[0016] In monomer II, p and q are the same or different and are each independently 1 or 2; R is the residue after removing OH from a Guerbet alcohol of C 8-16 such as the residue after removing OH from 2-EH alcohol (CAS No.: 104-76-7), 2-PH alcohol (CAS No.: 10042-59-8), isododecanol (CAS No.: 3913-02-8), and isocetyl alcohol (CAS No.: 2425-77-6); x is a number from 0.9 to 5, and y is a number from 10 to 20; R1 is -SO3NH4; E is (CH2)2, (CH2)3, or CH(CH3)-CH2; R2 is H or methyl.

[0017] In formula III, R3 is selected from H or C 1-3 alkyl; R4 is selected from H, COOH, or C 1-3 alkyl.

[0018] As an example, monomer I is

[0019] Monomer II has the following structure:

[0020]

[0021] The acrylic monomer is selected from acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, citraconic acid, or a salt or ester of any of the above acids (such as hydroxyethyl acrylate, hydroxypropyl acrylate, methyl methacrylate, ethyl methacrylate).

[0022] According to an embodiment of the present invention, the weight average molecular weight of the polymer is 8000 - 80000, for example 20000 - 50000, such as 22000 - 45000, 23000 - 43000, 24000 - 40000, 25000 - 38000, 26000 - 35000, 27000 - 33000.

[0023] According to an embodiment of the present invention, the copolymer is a copolymer obtained from monomer I, monomer II, and an acrylic monomer in the presence of a conversion agent; the conversion agent is selected from an aqueous solution of sodium stannate, and the mass ratio of sodium stannate to water in the aqueous solution is 1:1 - 1000, for example 1:5 - 100, such as 1:10.

[0024] The present invention also provides a method for preparing the copolymer as described above, including: polymerizing monomer I, monomer II, and an acrylic monomer.

[0025] According to an embodiment of the present invention, the reaction is carried out in the presence of a conversion agent.

[0026] According to an embodiment of the present invention, the method includes: polymerizing monomer I, monomer II, and an acrylic monomer in the presence of a conversion agent, an initiator, a reducing agent, and / or a chain transfer agent.

[0027] According to an embodiment of the present invention, the conversion agent is an aqueous solution of sodium stannate, and the mass ratio of sodium stannate to water in the aqueous solution is 1:1 - 1000, for example, 1:5 - 100, such as 1:10.

[0028] According to an embodiment of the present invention, the ratio of the mass of sodium stannate to the mass of monomer I is 1:(20 - 500), such as 1:(200 - 500), 1:(300 - 500), 1:(400 - 500), 1:(400 - 450).

[0029] According to an embodiment of the present invention, when the conversion agent is used, the conversion rate of monomer I is above 78%, for example, above 80%, such as above 85%, such as above 88%.

[0030] According to an embodiment of the present invention, the initiator is selected from one, two, or more of hydrogen peroxide, ammonium persulfate, sodium persulfate, potassium persulfate, and azodiisobutyramidine hydrochloride.

[0031] According to an embodiment of the present invention, the reducing agent is selected from one, two, or more of alkali metal sulfites, low oxidation compounds and their salts, such as hypophosphorous acid, sodium hypophosphite, sodium bisulfite, and sodium dithionite, ammonium ferrous sulfate, amines and their salts, L - ascorbic acid, L - ascorbate, L - ascorbate ester, isoascorbic acid, isoascorbate, and isoascorbate ester.

[0032] According to an embodiment of the present invention, the chain transfer agent is selected from one, two, or more of thiols, secondary alcohols, low - level oxidation compounds and their salts, such as phosphorous acid, hypophosphorous acid, sulfurous acid, sodium hypophosphite, potassium hypophosphite, bisulfite, sodium sulfite, sodium dithionite, sodium metabisulfite, potassium metabisulfite, mercaptopropionic acid, and mercaptoacetic acid.

[0033] According to an embodiment of the present invention, the temperature of the polymerization reaction can be 0 - 40°C, for example, 5°C, 10°C, 20°C, 30°C, 40°C.

[0034] According to an embodiment of the present invention, the dosage of the initiator is 0.001 - 5% of the total mass of the monomers, for example, 0.01% - 1.2% or 0.1 - 1%, such as 0.6%, 0.7%, 0.8%, 0.9%.

[0035] According to an embodiment of the present invention, the dosage of the reducing agent is 0.0001-0.5% of the total mass of the monomers, such as 0.01%-1% or 0.1%-0.5%, such as 0.2%, 0.3%, 0.4%.

[0036] According to an embodiment of the present invention, the dosage of the chain transfer agent is 0.001-8% of the total mass of the monomers, such as 0.5%-5% or 0.5%-2%, such as 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%.

[0037] According to an embodiment of the present invention, the monomer I can be prepared by the following method: in the presence of a basic catalyst, reacting the compound represented by formula IA with an epoxide.

[0038]

[0039] wherein, n has the definition as described above.

[0040] According to an embodiment of the present invention, the compound represented by formula IA is selected from vinyl ethylene glycol ether or diethylene glycol mono vinyl ether.

[0041] According to an embodiment of the present invention, two or more different epoxides can be used in the preparation of monomer I. For example, the epoxide is selected from one, two or more of ethylene oxide, propylene oxide, and butylene oxide, such as the epoxide is selected from a mixture of ethylene oxide and propylene oxide and / or butylene oxide. When using multiple epoxides, the epoxides can be combined into the structure of the compound represented by formula IA in a block or random manner.

[0042] According to an embodiment of the present invention, when using two different epoxides, the reaction can be carried out in more than two steps, and the basic catalyst in each step can be the same or different. For example, it is carried out in two steps, and the basic catalysts in step 1) and 2) can be independently selected from basic alkaline earth metal compounds and basic alkali metal compounds, such as oxides, carbonates, bicarbonates, hydroxides, alkoxides of alkali metals or alkaline earth metals, such as oxides, hydroxides, carbonates, methanolates or ethanolates of sodium, potassium, rubidium, cesium, calcium, and magnesium, and its examples can be one, two or more of potassium hydroxide, sodium hydroxide, and sodium methoxide.

[0043] According to an embodiment of the present invention, the molar ratio of the compound represented by formula IA to the epoxide can be 1:(1-50), preferably 1:(2-30), such as 1:(5-20).

[0044] According to an embodiment of the present invention, the molar ratio of the compound shown by formula IA to the basic catalyst may be 1:(0.005 - 0.025), preferably 1:(0.008 - 0.02).

[0045] According to an embodiment of the present invention, during the preparation of monomer I, the reaction temperature is above 80 °C, such as above 90 °C, above 95 °C, above 100 °C, for example, 90 - 130 °C, such as 105 - 110 °C.

[0046] According to an embodiment of the present invention, the reaction pressure during the preparation of monomer I is 0.01 - 2 Mpa, preferably 0.2 - 0.8 MPa.

[0047] According to an embodiment of the present invention, monomer II is prepared by the following method:

[0048] Step (1): ROH reacts with compound IIA to obtain intermediate Ila;

[0049]

[0050] Step (2): The intermediate Ila obtained in step (1) is subjected to alkoxylation reaction with an epoxide;

[0051] Optionally, it further includes step (3): Deriving the structure obtained in step (2);

[0052] Wherein, R, R2, p, and q have the definitions as described above.

[0053] According to an embodiment of the present invention, in the said step (1), ROH is a Guerbet alcohol of C 8-16 such as 2 - EH alcohol (CAS No.: 104 - 76 - 7), 2 - PH alcohol (CAS No.: 10042 - 59 - 8), isododecanol (CAS No.: 3913 - 02 - 8), and isocetyl alcohol (CAS No.: 2425 - 77 - 6). Further preferably 2 - PH alcohol.

[0054] According to an embodiment of the present invention, in the said step (1), compound IIA is selected from at least one of allyl glycidyl ether, acrylic acid glycidyl ether, and 4 - vinylbenzyl glycidyl ether, preferably allyl glycidyl ether.

[0055] According to an embodiment of the present invention, in the said step (1), the content of each structural unit in intermediate Ila can be changed by adjusting the ratio of ROH to compound IIA, thereby changing the structure of monomer II. The molar ratio of ROH to compound IIA can be 1:0.5 - 3, for example, 1:1 - 2.5.

[0056] According to an embodiment of the present invention, in step (1), the reaction temperature is 0 - 150 °C, for example 30 - 140 °C, such as 80 - 120 °C; the reaction pressure is atmospheric pressure - 2 MPa, for example atmospheric pressure - 1 MPa; the reaction time is 1 - 10 hours, for example 4 - 8 hours.

[0057] According to an embodiment of the present invention, in step (1), the reaction is carried out in the presence of a catalyst, and the catalyst is selected from reagents that can promote the ring-opening of alkylene oxides, such as one, two or more of potassium hydroxide, sodium hydroxide, sodium methoxide, potassium methoxide, sodium hydride, aluminum chloride, barium chloride, boron trifluoride or quaternary ammonium salts.

[0058] According to an embodiment of the present invention, in step (2), the alkylene oxide is any one, two or more of ethylene oxide, propylene oxide or butylene oxide, such as the alkylene oxide being a mixture of ethylene oxide and propylene oxide and / or butylene oxide. When using multiple alkylene oxides, the alkylene oxides can be incorporated into the structure of monomer II in a block or random manner.

[0059] According to an embodiment of the present invention, in step (2), the temperature of the alkoxylation reaction is 0 - 150 °C, for example 50 - 140 °C, such as 80 - 120 °C; the reaction pressure is atmospheric pressure - 2.0 MPa, for example atmospheric pressure - 0.5 MPa; the reaction time is 1 - 10 hours, for example 3 - 5 hours.

[0060] According to an embodiment of the present invention, in step (2), a catalyst can be optionally added or not added to the alkoxylation reaction, and the catalyst can be a reagent that promotes the ring-opening of alkylene oxides, such as one, two or more of potassium hydroxide, sodium hydroxide, sodium methoxide, potassium methoxide, sodium hydride, aluminum chloride, barium chloride, boron trifluoride or quaternary ammonium salts.

[0061] According to an embodiment of the present invention, in step (3), the derivatization can be any one of sulfonation, phosphorylation, or esterification.

[0062] As an example, when the derivatization is sulfonation, that is, introducing a -SO3M group into the reaction.

[0063] According to an embodiment of the present invention, in step (3), when the derivatization is sulfonation, the sulfonation reagent includes any one, two or more of SO3, fuming sulfuric acid, sulfuric acid, sulfuric acid aqueous solution, sulfamic acid, chlorosulfonic acid; the amount of the sulfonation reagent is 5 - 40 wt% of the amount of the product obtained in step (2), such as 8 - 20 wt%.

[0064] According to an embodiment of the present invention, in step (3), the temperature of the sulfonation reaction is 0 - 150 °C, for example 10 - 120 °C; the reaction pressure is atmospheric pressure - 2 MPa; the reaction time is 1 - 10 hours.

[0065] According to an embodiment of the present invention, in step (3), a catalyst may optionally be added or not added in the sulfonation reaction, and the catalyst may be one or more of urea, thiourea, ammonia, N,N-dimethylformamide, and N-methylpyrrolidone; the dosage of the catalyst is 0.5-5 wt% of the amount of the product obtained in step (2), for example, 1-3 wt%.

[0066] According to an embodiment of the present invention, in step (3), when the derivatization is phosphorylation, that is, -PO3M2 or -HPO3M group is introduced into the reaction.

[0067] According to an embodiment of the present invention, in step (3), the phosphorylation reagent for phosphorylation is at least one of phosphorus pentoxide, polyphosphoric acid, orthophosphoric acid, and phosphorus oxychloride; the dosage of the phosphorylation reagent is 5-40 wt% of the amount of the product obtained in step (2), for example, 10-30 wt%.

[0068] According to an embodiment of the present invention, in step (3), the reaction temperature for phosphorylation is room temperature - 150 °C; the reaction pressure is atmospheric pressure - 2 MPa; the reaction time is 1-10 hours.

[0069] The present invention also provides the use of the polymer as described above as a concrete admixture.

[0070] According to an embodiment of the present invention, the admixture is a water reducing agent.

[0071] Beneficial effects

[0072] 1. The present invention provides a concrete admixture. Since the unsaturated double bond in the monomer II molecule for preparing the admixture is at the hydrophobic end, it is more conducive to its copolymerization with other monomers, thereby anchoring the admixture molecule on the surface of cement particles; in addition, the special hydrophobic structure contained in its structure can make the prepared admixture not easily undergo physical desorption and aggregation during the cement hydration process, which can greatly improve the dispersibility and dispersion retention between particles; and, the special hydrophobic structure can make the prepared admixture have both the functions of viscosity reduction and water reduction.

[0073] 2. The raw materials of monomer II for preparing the admixture of the present invention have stable sources, low prices, and high double bond contents; and the raw material ratio can be adjusted according to actual product requirements, the preparation operation is simple, the conditions are easy to control, the preparation method is environmentally friendly, and no industrial three wastes are generated, which is suitable for industrial scale production.

[0074] 3. A conversion agent that can improve the monomer conversion rate is used in the synthesis of the admixture of the present invention, which can greatly improve the conversion rate of monomer I, thereby increasing the content of effective substances in the admixture.

[0075] 4. The concrete prepared by adding the admixture of the present invention has the advantages of low viscosity, good slump retention, water retention and workability. When in use, adding a small amount of the admixture can make the concrete meet the use requirements, thus reducing the cost of the concrete. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] Figure 1 It is the NMR spectrum of intermediate 2b.

[0077] Figure 2 It is the GPC spectrum of the admixture prepared in Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0078] The technical solutions of the present invention will be further described in detail below with reference to specific examples. It should be understood that the following examples are only for illustrative and explanatory purposes of the present invention, and should not be construed as limiting the protection scope of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0079] Unless otherwise specified, the raw materials and reagents used in the following examples are all commercially available products, or can be prepared by known methods.

[0080] Preparation Example 1

[0081] (1) Preparation of Monomer 1

[0082] Put vinyl ethylene glycol ether into a stainless steel high-pressure reactor, with an input amount of 564.46 g. Add 3.63 g of solid potassium hydroxide, displace with nitrogen, and then start heating with stirring. After the temperature rises to 110 °C, slowly introduce 2638.55 g of ethylene oxide into the reactor for polymerization reaction, maintain the temperature at 110 °C, and the pressure is relatively constant at about 0.3 MPa. When all the ethylene oxide is added to the reactor, keep it warm for about 1 hour until the pressure in the reactor no longer drops. After vacuum degassing, cool down to 80 °C and discharge to obtain intermediate 1 with a molecular weight of 482.

[0083] Put the intermediate 1 prepared in the above step into a stainless steel high-pressure reactor, with an input amount of 210.32 g. Add 1.85 g of 50% potassium hydroxide aqueous solution, dehydrate at 80 °C for 60 min, displace with nitrogen, and then start heating with stirring. After the temperature rises to 105 - 110 °C, slowly introduce 210.32 g of ethylene oxide into the reactor for polymerization reaction, maintain the temperature at 110 °C, and the pressure is relatively constant at about 0.4 MPa. When all the ethylene oxide is added to the reactor, keep it warm for about 1 hour until the pressure in the reactor no longer drops. After vacuum degassing, cool down to 80 °C and discharge to obtain monomer 1 with a molecular weight of 907.

[0084] (2) Preparation of Monomer 2

[0085] First, weigh 200 g of 2-PH alcohol (hydroxyl value 354.4 mg KOH / g) with qualified water content (<1000 ppm) into the reaction kettle, add 0.9 g of NaH, and under nitrogen protection, stir and heat up to 90 °C. Slowly dropwise add a total of 151.4 g of allyl glycidyl ether into the reaction kettle, finish dropping within 1 hour, continue stirring for 8 hours, cool down to 50 - 60 °C to obtain intermediate 1a, and its molecular weight is 272.44 tested by GPC.

[0086] Take 200 g of intermediate 1a and place it in the reaction kettle, add 0.8 g of potassium hydroxide and stir, displace with nitrogen, heat up to 85 °C to start dehydration for 1 hour, after the water content reaches the standard (<1000 ppm), continue heating up to 140 °C under nitrogen protection, slowly add 353.5 g of ethylene oxide into the reaction kettle, cure until the pressure remains unchanged and ensure the total reaction time is 4 hours to obtain intermediate 2a. Its molecular weight is 826 tested by GPC. Confirmed by NMR, the product structure is as follows:

[0087]

[0088] Perform a sulfonation reaction on intermediate 2a to convert the terminal H into a -SO3NH4 anionic group monomer. Add 150 g of sample 2a and 1.6 g of urea into the reaction flask, heat up to 100 °C under nitrogen protection, then add 12.3 g of sulfamic acid in 3 portions, continue stirring for 4 hours. Cool down, add the solvent ethanol, stir and filter to obtain product monomer 2-1 with -SO3NH4 end groups. Confirmed by NMR, the structure of monomer 2-1 is as shown below:

[0089]

[0090] Preparation Example 2

[0091] The difference from Preparation Example 1: Use isomeric C8 alcohol (2-EH alcohol) instead of C10 alcohol (2-PH alcohol) to prepare monomer 2-2. The structure of monomer 2-2 is as shown below:

[0092]

[0093] Preparation Example 3

[0094] First, weigh 200 g of 2-EH alcohol (hydroxyl value 431.5 mg KOH / g) with qualified water content (<1000 ppm) into the reaction kettle, add 0.9 g of NaH, and under nitrogen protection, stir and heat up to 90 °C. Slowly dropwise add a total of 184.5 g of allyl glycidyl ether into the reaction kettle, finish dropping within 1 hour, continue stirring for 8 hours, cool down to 50 - 60 °C to obtain intermediate 1b, and its molecular weight is 250.27 tested by GPC.

[0095] Take 200 g of intermediate 1b and place it in a reaction kettle. Add 0.8 g of potassium hydroxide and stir. Replace the air with nitrogen, heat up to 85 °C and start dehydration for 1 hour. After the water content meets the standard (<1000 ppm), continue to heat up to 140 °C under nitrogen protection, and slowly add 351.6 g of ethylene oxide to the reaction kettle. Cure until the pressure remains unchanged and ensure that the total reaction time is 4 hours to obtain intermediate 2b. Figure 1 For the 1 1H-NMR spectrum of intermediate 2b, and its molecular weight was measured by GPC to be 688.

[0096] 1 The 1H-NMR spectrum shows that: the chemical shift δ = 0.18 - 0.9 ppm is the chemical shift of the terminal CH3 of the alkyl chain; δ = 1.2 - 1.6 ppm is the chemical shift of CH2 in the alkyl chain; δ = 5.1 - 5.4 ppm is the chemical shift of the terminal CH2 of allyl alcohol; δ = 5.8 - 6.0 ppm is the chemical shift of CH in allyl alcohol; δ = 3.2 - 3.8 ppm is the chemical shift of CH2 in the alkoxy group; δ = 3.9 - 4.0 ppm is the chemical shift of CH2 connected to O in allyl alcohol; δ = 3.8 - 3.9 ppm is the chemical shift of CH in glycerol ether. Based on the above results, it can be speculated that intermediate 2b has the following structure:

[0097]

[0098] The sulfonation process of intermediate 2b is the same as that in Preparation Example 1 to obtain monomer 2 - 3 with a -SO3NH4 end group. The structure of monomer 2 - 3 is as follows:

[0099]

[0100] Preparation Example 4

[0101] The difference from Preparation Example 1 is that: a straight-chain alcohol (n-octanol) is used instead of a branched-chain alcohol (2-PH alcohol) to obtain monomer 2 - 4, and the structure of monomer 2 - 4 is as follows:

[0102]

[0103] Example 1

[0104] Dropwise addition material preparation: Mix 23 g of water, 9 g of acrylic acid, 0.5 g of mercaptoacetic acid, and 0.05 g of L-ascorbic acid and stir evenly for later use.

[0105] Conversion agent preparation: Dissolve 1 g of sodium stannate in 10 g of water for later use.

[0106] Put 31 g of monomer 1, 9.7 g of monomer 2-1, and 27 g of water into a four-necked flask, stir and melt at 23 ± 5 °C to make them evenly mixed. Add 0.5 g of hydrogen peroxide to the flask at 23 ± 5 °C, stir for 3 - 5 min, add 0.8 g of the conversion agent aqueous solution, and then add the prepared dropping material dropwise to the reaction kettle within 60 min, controlling the temperature in the reaction kettle within 40 °C. After dropping, keep warm and cure for 1 h to obtain sample admixture 1. The weight-average molecular weight and the conversion rate of monomer I obtained by GPC test are shown in Table 1.

[0107] Example 2

[0108] Refer to the preparation method of Example 1, the differences are: 8.4 parts of acrylic acid, 10.3 parts of monomer 2-1, 0.4 part of mercaptoacetic acid, and others remain unchanged.

[0109] Example 3

[0110] Refer to the preparation method of Example 1, the differences are: 10.7 parts of acrylic acid, 10.3 parts of monomer 2-2, 0.8 part of mercaptoacetic acid, and others remain unchanged.

[0111] Example 4

[0112] Refer to the preparation method of Example 1, the differences are: 35 parts of monomer 1, 4.7 parts of monomer 2-3, and others remain unchanged.

[0113] Example 5

[0114] Refer to the preparation method of Example 1, the difference is: no conversion agent is added, and others remain unchanged.

[0115] Comparative Example 1

[0116] Refer to the preparation method of Example 1, the difference is: monomer 2 uses 2-4.

[0117] Comparative Example 2

[0118] The concrete admixture selects the water reducer CP1200 produced by Nanjing Chuhai New Material Technology Co., Ltd., a commercially available viscosity-reducing type.

[0119] Implementation effect

[0120] 1. Cement paste fluidity test

[0121] To investigate the effect of the viscosity-reducing and water-reducing admixture of the present invention on the fluidity of different cements, the cement paste fluidity of the admixtures prepared in the examples and comparative examples was measured under the same dosage. The test was carried out according to GB / T8077-2000 "Test Methods for the Homogeneity of Concrete Admixtures", the water-cement ratio W / C = 0.29, and the dosage of the admixture in the cement was 0.2 wt%. The test results are shown in Table 1.

[0122] 2. Measurement of the backflow time of neat cement paste

[0123] Select a No. 4 viscosity cup to measure the backflow time of neat cement paste. Fix the water consumption and cement consumption, adjust the dosage of the admixture. After making the size of the neat paste close to 200 ± 5 mm, measure its backflow time. The test results are shown in Table 2.

[0124] Table 1 Results of the fluidity, molecular weight and monomer conversion rate of neat cement paste

[0125]

[0126] In Table 1, " / " indicates that the data does not exist.

[0127] As can be seen from Table 1, the viscosity-reducing agent of the present invention has both water-reducing admixture properties. Compared with the commercially available viscosity-reducing polycarboxylate-based water-reducing agent, it has more excellent water-reducing performance, neat paste dispersion performance and retention performance. The admixture in Example 3 has the best dispersion and retention performance. In addition, when preparing monomer II in Examples 1-4, alcohols containing branched-chain saturated hydrocarbon groups are used. Compared with the monomer prepared using alcohols containing straight-chain saturated hydrocarbon groups in Comparative Example 1, the water-reducing agent finally prepared significantly improves its water-reducing performance, neat paste dispersion performance and retention performance.

[0128] Table 2 Viscosity test of neat cement paste

[0129]

[0130]

[0131] As can be seen from Table 2, the viscosity-reducing agent of the present invention has both water-reducing admixture properties. Compared with the commercially available viscosity-reducing polycarboxylate-based water-reducing agent, the backflow time is shorter under the same conditions, indicating that its viscosity-reducing effect is better. Among them, the admixture prepared in Example 1 has the shortest backflow time and the best viscosity-reducing effect.

[0132] The above describes the embodiments of the present invention. However, the present invention is not limited to the above embodiments. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A polymer, characterized in that, It is a copolymer of monomer I, monomer II and an acrylic monomer as follows: In monomer I, m is a number from 1 to 50, n is 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10; A is selected from C which is unsubstituted or optionally substituted by one, two or more Ra 2-10 alkylene; Ra is selected from halogen, C 1-12 alkyl, halo-C 1-12 alkyl or C 1-12 alkoxy; In monomer II, p and q are the same or different and are each independently 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10; R is a branched-chain saturated hydrocarbon group of C 4-20 ; x is a number from 0.1 to 20; y is a number from 0.5 to 50; R2 is selected from H or C 1-12 alkyl; Q is C 1-10 alkylene, CO or sub-C 6-14 aryl; E is C 2-12 alkylene; R1 is selected from a hydrogen atom or an ionic hydrophilic group; The acrylic monomer is selected from the structure shown in the following formula III, its ester, salt or anhydride; In formula III, R3 is selected from H or C 1-12 alkyl; R4 is selected from H, COOH, C 1-12 alkyl or -C 1-12 alkyl COOH.

2. The polymer according to claim 1, wherein The molar ratio of monomer I, acrylic monomer and monomer II in the polymer is 1:1 - 10:0.1 - 1; Preferably, the molar number of monomer I in the polymer is 2 - 20.

3. The polymer according to claim 1 or 2, characterized in that, In monomer I, A is selected from the following groups which are unsubstituted or optionally substituted by C 1-6 alkyl: C 2-10 alkylene, for example, A is selected from (CH2)2, (CH2)3, CH(CH3)-CH2, (CH2)4, (CH2)5, (CH2)6, (CH2)7, (CH2)8, (CH2)9, (CH2) 10 , [CH(CH3)]2; n is selected from 1, 2, 3, 4 or 5; m is a number from 5 to 35; In monomer II, p and q are the same or different and are independently 0, 1, 2 or 3; R is a branched-chain saturated hydrocarbon group of C 5-15 ; x is a number from 0.5 to 10, y is a number from 3 to 30; Q is methylene, CO or phenylene; E is C 2-6 alkylene; R1 is selected from H, -SO3M, -COOM, -PO3M2 or -HPO3M; where M is selected from hydrogen ion, alkali metal ion, alkaline earth metal ion, ammonium ion (NH4 + ), quaternary ammonium cation; R2 is H or C 1-6 alkyl. In formula III, R3 is selected from H or C 1-6 alkyl; R4 is selected from H, COOH, C 1-6 alkyl or -C 1-6 alkyl COOH.

4. The polymer according to any one of claims 1 - 3, characterized in that, In monomer I, A is selected from CH(CH3)-CH2, (CH2)2 or (CH2)3, n is selected from 1, 2 or 3; m is selected from numbers from 5 to 20; In monomer II, p and q are the same or different and are each independently 1 or 2; R is the residue after removing OH from a Guerbet alcohol of C 8-16 , for example, R is the residue after removing OH from 2-EH alcohol (CAS No.: 104-76-7), 2-PH alcohol (CAS No.: 10042-59-8), isododecanol (CAS No.: 3913-02-8), and isocetyl alcohol (CAS No.: 2425-77-6); x is a number from 0.9 to 5, and y is a number from 10 to 20; R1 is -SO3NH4; E is (CH2)2, (CH2)3, or CH(CH3)-CH2; R2 is H or methyl; In formula III, R3 is selected from H or C 1-3 alkyl; R4 is selected from H, COOH or C 1-3 alkyl.

5. The polymer according to any one of claims 1-4, characterized in that, Monomer I is Monomer II has the following structure: The acrylic monomer is selected from acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, citraconic acid, or a salt or ester of any one of the above acids (such as hydroxyethyl acrylate, hydroxypropyl acrylate, methyl methacrylate, ethyl methacrylate).

6. The polymer according to any one of claims 1-5, characterized in that, The weight average molecular weight of the polymer is 8000 - 80000.

7. A method for preparing the polymer according to any one of claims 1-6, characterized in that, Including: Polymerize monomer I, monomer II and the acrylic monomer.

8. The preparation method according to claim 7, wherein, The method includes: polymerizing monomer I, monomer II and the acrylic monomer in the presence of a conversion agent, an initiator, a reducing agent and / or a chain transfer agent; Preferably, the conversion agent is an aqueous solution of sodium stannate, and the mass ratio of sodium stannate to water in the aqueous solution is 1:1 - 1000; Preferably, the mass ratio of sodium stannate to monomer I is 1:(20 - 500); Preferably, when using the conversion agent, the conversion rate of monomer I is above 78%; Preferably, the initiator is selected from one, two or more of hydrogen peroxide, ammonium persulfate, sodium persulfate, potassium persulfate, azodiisobutyramidine hydrochloride; Preferably, the reducing agent is selected from one, two or more of alkali metal sulfites, low oxidation compounds and their salts, such as hypophosphorous acid, sodium hypophosphite, sodium bisulfite and sodium dithionite, ammonium ferrous sulfate, amines and their salts, L-ascorbic acid, L-ascorbate, L-ascorbate ester, isoascorbic acid, isoascorbate and isoascorbate ester; Preferably, the chain transfer agent is selected from one, two or more of mercaptans, secondary alcohols, low oxidation compounds and their salts, such as phosphorous acid, hypophosphorous acid, sulfurous acid, sodium hypophosphite, potassium hypophosphite, bisulfite, sodium sulfite, sodium dithionite, sodium metabisulfite, potassium metabisulfite, mercaptopropionic acid and mercaptoacetic acid; Preferably, in step (3), the derivatization is any one of sulfonation, phosphorylation, and esterification.

9. Use of the polymer according to any one of claims 1 - 6 as a concrete admixture.

10. The use according to claim 9, wherein, The admixture is a water reducing agent.

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