High-adaptability viscosity-reducing polycarboxylic acid water reducer, preparation method therefor and use thereof

Abstract

Disclosed are a highly adaptable viscosity-reducing polycarboxylate water reducer and its preparation method and application. The highly adaptable viscosity-reducing polycarboxylate water reducer is composed of a polymer and water, and the polymer accounts for 30-50 wt %; since the main chain of the polymer contains a hydrophobic benzene ring and hydrophilic amine, the polymer has strong rigidity and good solubility in an aqueous solution, and is rich in two adsorption groups of carboxyl group/phosphono group. The highly adaptable viscosity-reducing polycarboxylate water reducer of the present invention has excellent water-reducing and slump retention properties and is suitable for general construction projects and commercial concrete projects. Compared with the conventional polycarboxylate water reducer, the highly adaptable viscosity-reducing polycarboxylate water reducer of the present invention has strong adaptability to concrete materials and can effectively reduce the viscosity of high-strength concrete (C50-C100), thus having bright application prospects in the high-end water reducer market.

Claims

1. A viscosity-reducing polycarboxylate water reducer, comprising a polymer and water, the polymer accounts for 30-50 wt %; the polymer has polyether side chains, a main chain of the polymer contains a hydrophobic benzene ring and hydrophilic amine, soluble in an aqueous solution, and is having two adsorption groups, carboxyl group and phosphono group; wherein the main chain is prepared through a polycondensation reaction among an aromatic compound, a polyamine compound, and an alkyl aldehyde; the aromatic compound includes hydroxybenzoic acid and phenylphosphonic acid monomers, and the aromatic compound and the polyamine compound are randomly distributed in the main chain.

2. The viscosity-reducing polycarboxylate water reducer according to claim 1, wherein the hydroxybenzoic acid is any one of o-hydroxybenzoic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, 2,3-dihydroxybenzoic acid, and 3,4-dihydroxybenzoic acid or a combination of more than two of o-hydroxybenzoic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, 2,3-dihydroxybenzoic acid, and 3,4-dihydroxybenzoic acid in any ratio.

3. The viscosity-reducing polycarboxylate water reducer according to claim 1, wherein the phenylphosphonic acid monomer is represented by a structural formula B-1 or B-2: ##STR00005## wherein X represents O or NR.sub.2, Y represents alkylene with 1 to 4 carbon atoms, Z represents N(CH.sub.2PO.sub.3H.sub.2).sub.2, NHCH.sub.2PO.sub.3H.sub.2, NR.sub.3CH.sub.2PO.sub.3H.sub.2, C(OH)(PO.sub.3H.sub.2).sub.2, CH(OPO.sub.3H.sub.2)CH.sub.2OPO.sub.3H.sub.2 or OPO.sub.3H.sub.2, R.sub.1 represents alkyl with 1 to 4 carbon atoms, G represents OH or NR.sub.4, and R.sub.2, R.sub.3, and R.sub.4 independently represent alkyl with 1 to 4 carbon atoms.

4. The viscosity-reducing polycarboxylate water reducer according to claim 1, wherein the polyamine compound is any one of m-xylylenediamine, ethylenediamine, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine or a combination of more than two of m-xylylenediamine, ethylenediamine, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine in any ratio.

5. The viscosity-reducing polycarboxylate water reducer according to claim 1, wherein the alkyl aldehyde is formaldehyde, acetaldehyde, propionaldehyde, or the alkyl aldehyde is paraformaldehyde.

6. The viscosity-reducing polycarboxylate water reducer according to claim 1, wherein the weight-average molecular weight M.sub.w of the viscosity-reducing polycarboxylate water reducer is between 20,000 and 80,000.

7. A method to prepare the viscosity-reducing polycarboxylate water reducer according to claim 6, wherein a linear main chain polymer is first prepared by a polycondensation reaction from monomer A, monomer B, monomer C, and aldehyde D, and then polyether macromonomer E is grafted onto the main chain through chemical bonding to form a comb-shaped polymer, thereby obtaining the viscosity-reducing polycarboxylate water reducer; the monomer A is hydroxybenzoic acid, the monomer B is a phenylphosphonic acid monomer, the monomer C is a polyamine compound, the aldehyde D is an alkyl aldehyde; the polyether macromonomer E is a polyethylene glycol monomethyl ether containing a special group at the end, which is presented by a structural formula E-1 or E-2: ##STR00006## wherein R.sub.5 represents Cl or Br, n represents the number of repeating units with the specific value of 11-113, and the molecular weight of the polyether macromonomer E is 500-5000; the ends of the polyether macromonomer E contain epoxy or halogen groups which can react with the active hydrogen on the amino group, so that the polyether monomer E can be grafted onto the polymer main chain containing the amino group.

8. The method according to claim 7, wherein the preparation method of the viscosity-reducing polycarboxylate water reducer specifically has the following two steps: (1) preparing main chain: adding monomer A, monomer B, monomer C and water to a reaction flask, mixing evenly, heating to 100-150? C., and then dropwise adding an aqueous solution of aldehyde D to the reaction system, and reacting for 8-16 h to obtain a main chain polymer, wherein the molar ratio of the monomer A to monomer B to monomer C is 1:0.2-1.5:0.1-1.5; the molar amount of the aldehyde D is 105-110% of the total molar amount of the monomers A, B, and C; the water accounts for 20-60 wt % of the total mass of the monomers A, B, and C (2) introducing side chains: cooling the main chain polymer prepared in step (1) to 30-80? C., and then adding the polyether macromonomer E, holding the temperature and carrying out the reaction for 2-6 hours to obtain the viscosity-reducing polycarboxylate water reducer, wherein the molar ratio of the polyether macromonomer E to the monomer C in step (1) is 1-4:1.

9. A method of using a viscosity-reducing polycarboxylate water reducer, comprising providing the viscosity-reducing polycarboxylate water reducer according to claim 6, wherein the dosage of the viscosity-reducing polycarboxylate water reducer is 0.05% to 0.3% of a mass of a mixture of cementitious materials, the dosage refers to the pure solid dosage, and the percentage refers to the mass percentage; the viscosity-reducing polycarboxylate water reducer can be used together with other commercially available water reducers, such as lignosulfonate water reducers, naphthalene sulfonate water reducers, polycarboxylate water reducers, and can also be used after being mixed with an air-entraining agent, a retarder, an early strength agent, an expanding agent, a tackifier, a shrinkage reducing agent and a defoaming agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

(1) The preparation process of the highly adaptable viscosity-reducing polycarboxylate water reducer of the present invention will be detailed below by embodiments. These embodiments are given by way of illustration for the purpose that those familiar with this technology can understand the content of the present invention and implement it accordingly, but these embodiments in no way limit the scope of the present invention. All equivalent changes or modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

(2) The phenyl phosphate monomer B used in the embodiments of the present invention was self-made according to the patent CN 105646871A, the polyether macromonomer E was purchased from Xiamen Sinopeg Biotech Co., Ltd, and all other raw materials were commercially available ordinary analytical chemical reagents, purchased from Sinopharm Group Chemical Reagent Co., Ltd.

(3) The serial numbers of some monomers B used in the embodiments of the present invention are as follows:

(4) ##STR00003## ##STR00004##

(5) In the embodiments of the present invention, the weight-average molecular weights of the polymers were determined by gel permeation chromatographer of Wyatt technology corporation. (Gel column: Shodex SB806+803 two chromatographic columns in series; eluent: 0.1 M NaNO.sub.3 solution; mobile phase velocity: 1.0 ml/min; detector: Shodex RI-7 refractive index detector; molecular weight standard: Polyethylene glycol GPC standard sample (Sigma-Aldrich, molecular weight: 1010000, 478000, 263000, 118000, 44700, 18600, 6690, 1960, 628, and 232).

Example 1

(6) (1) Preparation of main chain: 138 g (1.0 mol) of o-hydroxybenzoic acid, 65 g (0.20 mol) of a phenyl phosphate monomer P-1, 6 g (0.10 mol) of ethylenediamine and 100 g of water were added to a four-necked flask equipped with a thermometer and a mechanical stirrer and mixed evenly, the flask was then put in a 100? C. constant-temperature oil bath, 114 g (1.4 mol) of 37% formaldehyde solution was dropwise added to the flask for 1 h and then the reaction was carried out for 7 h whiling holding the temperature, thus obtaining a main chain polymer;

(7) (2) The introduction of side chains: the reaction flask was cooled to 30? C., 900 g (0.18 mol) of an epoxy-terminated polyether monomer with a molecular weight of 5000 was then added at a time, the reaction was carried out for 2 h while holding the temperature, 1200 g of water was then added for dilution to obtain the highly adaptable viscosity-reducing polycarboxylate water reducer. GPC test showed that the weight-average molecular weight M.sub.w was 39,200 and the molecular weight distribution coefficient was 2.05.

Example 2

(8) (1) Preparation of main chain: 138 g (1.0 mol) of m-hydroxybenzoic acid, 124.8 g (0.40 mol) of a phenyl phosphate monomer P-2, 6 g (0.10 mol) of ethylenediamine and 160 g of water were added to a four-necked flask equipped with a thermometer and a mechanical stirrer and mixed evenly, the flask was then put in a 100? C. constant-temperature oil bath, 130 g (1.6 mol) of 37% formaldehyde solution was dropwise added to the flask for 1 h and then the reaction was carried out for 7 h whiling holding the temperature, thus obtaining a main chain polymer;

(9) (2) The introduction of side chains: the reaction flask was cooled to 40? C., 600 g (0.15 mol) of an epoxy-terminated polyether monomer with a molecular weight of 4000 was then added at a time, the reaction was carried out for 2 h while holding the temperature, 850 g of water was then added for dilution to obtain the highly adaptable viscosity-reducing polycarboxylate water reducer. GPC test showed that the weight-average molecular weight M.sub.w was 34200 and the molecular weight distribution coefficient was 2.42.

Example 3

(10) (1) Preparation of main chain: 138 g (1.0 mol) of p-hydroxybenzoic acid, 249.6 g (0.80 mol) of a phenyl phosphate monomer P-3, 30.9 g (0.30 mol) of diethylenetriamine and 100 g of water were added to a four-necked flask equipped with a thermometer and a mechanical stirrer and mixed evenly, the flask was then put in a 100? C. constant-temperature oil bath, 262 g (2.2 mol) of 37% acetaldehyde solution was dropwise added to the flask for 1 h and then the reaction was carried out for 9 h whiling holding the temperature, thus obtaining a main chain polymer;

(11) (2) The introduction of side chains: the reaction flask was cooled to 50? C., 2400 g (0.60 mol) of an epoxy-terminated polyether monomer with a molecular weight of 4000 was then added at a time, the reaction was carried out for 2 h while holding the temperature, 2650 g of water was then added for dilution to obtain the highly adaptable viscosity-reducing polycarboxylate water reducer. GPC test showed that the weight-average molecular weight M.sub.w was 30500 and the molecular weight distribution coefficient was 2.34.

Example 4

(12) (1) Preparation of main chain: 154 g (1.0 mol) of 2,3-dihydroxybenzoic acid, 294 g (1.2 mol) of a phenyl phosphate monomer P-4, 30.9 g (0.30 mol) of diethylenetriamine and 150 g of water were added to a four-necked flask equipped with a thermometer and a mechanical stirrer and mixed evenly, the flask was then put in a 100? C. constant-temperature oil bath, 348 g (2.4 mol) of 40% propionaldehyde solution was dropwise added to the flask for 1 h and then the reaction was carried out for 11 h whiling holding the temperature, thus obtaining a main chain polymer;

(13) (2) The introduction of side chains: the reaction flask was cooled to 60? C., 2016 g (0.84 mol) of an epoxy-terminated polyether monomer with a molecular weight of 2400 was then added at a time, the reaction was carried out for 2 h while holding the temperature, 3350 g of water was then added for dilution to obtain the highly adaptable viscosity-reducing polycarboxylate water reducer. GPC test showed that the weight-average molecular weight M.sub.w was 26400 and the molecular weight distribution coefficient was 2.06.

Example 5

(14) (1) Preparation of main chain: 154 (1.0 mol) of 3,4-hydroxybenzoic acid, 487.5 g (1.5 mol) of a phenyl phosphate monomer P-5, 81.6 g (0.60 mol) of m-xylylenediamine and 350 g of water were added to a four-necked flask equipped with a thermometer and a mechanical stirrer and mixed evenly, the flask was then put in a 120? C. constant-temperature oil bath, 219 g (2.7 mol) of 37% formaldehyde solution was dropwise added to the flask for 1 h and then the reaction was carried out for 11 h whiling holding the temperature, thus obtaining a main chain polymer;

(15) (2) The introduction of side chains: the reaction flask was cooled to 70? C., 3600 g (1.5 mol) of an epoxy-terminated polyether monomer with a molecular weight of 2400 was then added at a time, the reaction was carried out for 4 h while holding the temperature, 4200 g of water was then added for dilution to obtain the highly adaptable viscosity-reducing polycarboxylate water reducer. GPC test showed that the weight-average molecular weight M.sub.w was 20,800 and the molecular weight distribution coefficient was 2.44.

Example 6

(16) (1) Preparation of main chain: 138 g (1.0 mol) of o-hydroxybenzoic acid, 338 g (1.0 mol) of a phenyl phosphate monomer P-6, 92.7 g (0.90 mol) of diethylenetriamine and 300 g of water were added to a four-necked flask equipped with a thermometer and a mechanical stirrer and mixed evenly, the flask was then put in a 120? C. constant-temperature oil bath, 178.4 g (2.2 mol) of 37% formaldehyde solution was dropwise added to the flask for 1 h and then the reaction was carried out for 11 h whiling holding the temperature, thus obtaining a main chain polymer;

(17) (2) The introduction of side chains: the reaction flask was cooled to 70? C., 5400 g (2.25 mol) of an epoxy-terminated polyether monomer with a molecular weight of 2400 was then added at a time, the reaction was carried out for 4 h while holding the temperature, 6600 g of water was then added for dilution to obtain the highly adaptable viscosity-reducing polycarboxylate water reducer. GPC test showed that the weight-average molecular weight M.sub.w was 29500 and the molecular weight distribution coefficient was 2.26.

Example 7

(18) (1) Preparation of main chain: 138 g (1.0 mol) of m-hydroxybenzoic acid, 312 g (1.0 mol) of a phenyl phosphate monomer P-2, 72 g (1.20 mol) of ethylenediamine and 300 g of water were added to a four-necked flask equipped with a thermometer and a mechanical stirrer and mixed evenly, the flask was then put in a 120? C. constant-temperature oil bath, 178.4 g (2.2 mol) of 37% formaldehyde solution was dropwise added to the flask for 1 h and then the reaction was carried out for 11 h whiling holding the temperature, thus obtaining a main chain polymer;

(19) (2) The introduction of side chains: the reaction flask was cooled to 50? C., 1440 g (1.2 mol) of an epoxy-terminated polyether monomer with a molecular weight of 1200 was then added at a time, the reaction was carried out for 3 h while holding the temperature, 2700 g of water was then added for dilution to obtain the highly adaptable viscosity-reducing polycarboxylate water reducer. GPC test showed that the weight-average molecular weight M.sub.w was 51,300 and the molecular weight distribution coefficient was 2.33.

Example 8

(20) (1) Preparation of main chain: 138 g (1.0 mol) of p-hydroxybenzoic acid, 312 g (1.0 mol) of a phenyl phosphate monomer P-2, 90 g (1.5 mol) of ethylenediamine and 220 g of water were added to a four-necked flask equipped with a thermometer and a mechanical stirrer and mixed evenly, the flask was then put in a 130? C. constant-temperature oil bath, 170 g (2.1 mol) of 37% formaldehyde solution was dropwise added to the flask for 1 h and then the reaction was carried out for 14 h whiling holding the temperature, thus obtaining a main chain polymer;

(21) (2) The introduction of side chains: the reaction flask was cooled to 40? C., 1125 g (2.25 mol) of a chlorine atom terminated polyether monomer with a molecular weight of 500 was then added at a time, the reaction was carried out for 4 h while holding the temperature, 1280 g of water was then added for dilution to obtain the highly adaptable viscosity-reducing polycarboxylate water reducer. GPC test showed that the weight-average molecular weight M.sub.w was 42,600 and the molecular weight distribution coefficient was 2.17.

Example 9

(22) (1) Preparation of main chain: 138 g (1.0 mol) of o-hydroxybenzoic acid, 249.6 g (0.80 mol) of a phenyl phosphate monomer P-3, 73 g (0.50 mol) of triethylenetetramine and 200 g of water were added to a four-necked flask equipped with a thermometer and a mechanical stirrer and mixed evenly, the flask was then put in a 130? C. constant-temperature oil bath, 154 g (1.9 mol) of 37% formaldehyde solution was dropwise added to the flask for 1 h and then the reaction was carried out for 15 h whiling holding the temperature, thus obtaining a main chain polymer;

(23) (2) The introduction of side chains: the reaction flask was cooled to 40? C., 4200 g (1.75 mol) of a chlorine atom terminated polyether monomer with a molecular weight of 2400 was then added at a time, the reaction was carried out for 3 h while holding the temperature, 4600 g of water was then added for dilution to obtain the highly adaptable viscosity-reducing polycarboxylate water reducer. GPC test showed that the weight-average molecular weight M.sub.w was 67,500 and the molecular weight distribution coefficient was 2.12.

Example 10

(24) (1) Preparation of main chain: 138 g (1.0 mol) of o-hydroxybenzoic acid, 122.5 g (0.50 mol) of a phenyl phosphate monomer P-4, 18.9 g (0.10 mol) of tetraethylenepentamine and 150 g of water were added to a four-necked flask equipped with a thermometer and a mechanical stirrer and mixed evenly, the flask was then put in a 150? C. constant-temperature oil bath, 130 g (1.6 mol) of 37% formaldehyde solution was dropwise added to the flask for 1 h and then the reaction was carried out for 15 h whiling holding the temperature, thus obtaining a main chain polymer;

(25) (2) The introduction of side chains: the reaction flask was cooled to 40? C., 1200 g (0.40 mol) of a bromine atom terminated polyether monomer with a molecular weight of 3000 was then added at a time, the reaction was carried out for 4 h while holding the temperature, 1850 g of water was then added for dilution to obtain the highly adaptable viscosity-reducing polycarboxylate water reducer. GPC test showed that the weight-average molecular weight M.sub.w was 79,200 and the molecular weight distribution coefficient was 2.40.

Comparative Example 1

(26) 240 g (0.10 mol) of methallyl polyoxyethylene ether with a molecular weight of 2400, 1.13 g (0.010 mol) of 30% hydrogen peroxide and 240 g of water were added into a four-necked flask equipped with a thermometer and a mechanical stirrer, and then the solution was sterred and heated to 40? C., a mixed solution consisting of 28.8 g (0.40 mol) of acrylic acid, 1.33 g (0.0125 mol) of 3-mercaptopropionic acid, 0.44 g (0.0025 mol) of L-ascorbic acid, and 30 g of water was dropwise added at 40? C. for 30 min, and then the resulting solution was maintained at this temperature for 1 h. The resulting product is a conventional polycarboxylate water reducer prepared by a conventional method in the laboratory. GPC test showed that M.sub.w was 31,700 and the molecular weight distribution coefficient was 1.82.

Comparative Example 2

(27) Commercially available high-performance polycarboxylate water reducer, purchased from KZJ New Materials Group Co., Ltd. and having M.sub.w of 30,600 and the molecular weight distribution coefficient of 1.71, tested by GPC.

Comparative Example 3

(28) A viscosity-reducing polycarboxylate water reducer synthesized with reference to CN 105367721 B, Example 4, having M.sub.w of 28,500 and a molecular weight distribution coefficient of 1.66, tested by GPC.

Comparative Example 4

(29) A highly adaptable polycarboxylate water reducer synthesized with reference to CN 104177557 B, Example 2, having M.sub.w of 37,200 and a molecular weight distribution coefficient of 1.82, tested by GPC.

Application Example 1

(30) According to the provisions in GB/T8077-2000 Test Method for Homogeneity of Concrete Admixtures, the highly adaptable viscosity-reducing polycarboxylate water reducer synthesized in the examples of the present invention and the samples of the comparative examples were subjected to the measurement of the cement paste fluidity. It is specified that the water-cement ratio is 0.29 and the solid dosage of the polycarboxylate water reducer is 0.10%; the cement used in the test was Jiangnan-Onoda PII 52.5 cement. The results of cement paste are shown in table 1.

(31) TABLE-US-00001 TABLE 1 Test results of cement paste fluidity Cement paste fluidity (mm) Sample 0 min 20 min 40 min 60 min Example 1 242 225 193 174 Example 2 250 227 198 171 Example 3 258 231 199 181 Example 4 260 233 203 183 Example 5 260 226 208 180 Example 6 265 229 202 189 Example 7 259 217 195 184 Example 8 263 222 208 186 Example 9 254 220 204 187 Example 10 241 215 200 182 Comparative 256 216 200 181 Example 1 Comparative 251 217 202 184 Example 2 Comparative 206 185 146 118 Example 3 Comparative 219 176 139 112 Example 4

(32) It can be seen from the test data in Table 1 that under the same dosage and water-cement ratio conditions, the initial fluidity of the samples of the examples can reach 241-265 mm, and after 60 minutes the fluidity still can reach 171-189 mm; the liquidity loss is only about 30%. Compared with the conventional polycarboxylate water reducers in the comparative examples (Comparative Examples 1 and 2), the samples of the examples have similar initial fluidity and time-dependent fluidity; compared with the highly adaptable or viscosity-reducing water reducers synthesized according to the patents (Comparative Examples 3 and 4), the samples of the examples significantly has larger initial fluidity and time-dependent fluidity. This indicates that the highly adaptable viscosity-reducing polycarboxylate water reducers synthesized in the examples of the present invention have good initial dispersion and slump retention properties, and do not sacrifice water-reducing ability because of other excellent properties. Compared with the water reducers synthesized in the examples, the high-adaptability or viscosity-reducing water reducers synthesized according to the patents have poor water-reducing performance.

Application Example 2

(33) According to the provisions of GB/T8077-2000 Test Method for Homogeneity of Concrete Admixtures, it is specified that the water-cement ratio is 0.29 and the solid dosage of the polycarboxylate is 0.10%. Cements in different regions were selected, and the adaptability of the highly adaptable viscosity-reducing polycarboxylate water reducers synthesized in the examples of the present invention to different cement was investigated. Concrete paste results are shown in Table 2.

(34) TABLE-US-00002 TABLE 2 Sensitivity test results of water reducers to different cement Relative standard Cement paste fluidity (mm) deviation of China United liquidity Onoda concrete concrete Conch concrete (RSD, %) Sample 0 min 60 min 0 min 60 min 0 min 60 min 0 min 60 min Example 1 242 174 225 172 265 199 7.89 6.76 Example 2 250 171 246 183 275 189 4.99 4.13 Example 3 258 181 244 186 272 192 4.43 2.41 Example 4 260 183 245 183 273 195 4.41 3.03 Example 5 260 180 248 185 275 196 4.23 3.57 Example 6 265 189 251 187 280 200 4.46 2.98 Example 7 259 184 244 187 272 202 4.43 4.12 Example 8 263 186 250 190 281 194 4.80 1.72 Example 9 254 187 238 185 264 197 4.25 2.77 Example 10 241 182 240 190 255 197 2.79 3.23 Comparative 256 181 192 156 277 205 14.96 11.07 Example 1 Comparative 251 184 180 144 223 188 13.39 11.55 Example 2 Comparative 206 118 175 150 244 174 13.54 15.57 Example 3 Comparative 219 112 182 133 230 130 9.76 7.42 Example 4

(35) It can be seen from the test data in Table 2 that in three different cements, the samples of the examples are not quite different in term of fluidity, and the difference between the maximum fluidity and the minimum fluidity is less than 30 mm, which indicates that the highly adaptable viscosity-reducing polycarboxylate water reducers synthesized in the examples of the present invention have strong adaptability to different cement. Relative standard deviation (RSD) of fluidity is used to quantify the adaptability of a water reducer to cement. A large RSD of fluidity indicates that the product performance fluctuates greatly, indicating that the product has poor adaptability to different cement. For the initial fluidity, the RSDs of Examples 1-10 are between 2.79% and 7.89%. The RSD of Comparative Examples 1-3 is between 13.39% and 14.96%, which is nearly twice the maximum value of RSD (7.89%) of the examples. Comparative Example 4 (highly adaptable polycarboxylate water reducer synthesized according to the patent) has an RSD of 9.76%, which is twice the average RSD of the examples. For a 60 min fluidity, the RSD of the examples is between 1.72% and 6.76%. The RSD of Comparative Examples 1-3 is between 11.07% and 15.57%, which is much higher than that of the Examples, while the RSD of Comparative Example 4 is 7.42%, which is also higher than that of the Examples.

(36) In summary, the adaptability of the highly adaptable viscosity-reducing polycarboxylate water reducers synthesized in the examples of the present invention to different cement is much stronger than that of conventional polycarboxylate water reducers, and also stronger than that of other highly adaptable polycarboxylate water reducers synthesized according to the patents.

Application Example 3

(37) According to the provisions of GB/T8077-2000 Test Method for Homogeneity of Concrete Admixtures, the fixed water-cement ratio is 0.50, the cement-sand ratio is 0.50, the solid dosage of the polycarboxylate is 0.12%. Three sand samples in different regions were selected, and the adaptability of the highly adaptable viscosity-reducing polycarboxylate water reducers synthesized in the examples of the present invention to different sands was investigated and the results are shown in Table 3. The cement used in the test was Onoda P II 52.5 cement. The specific parameters of the sand samples used were: Luoma Lake sand with a fineness modulus of 2.9; Mingguang machine-made sand with a fineness modulus of 2.5; Zhongshi river sand with fineness modulus of 2.7.

(38) TABLE-US-00003 TABLE 3 Sensitivity test results of water reducers to different sands Cement paste fluidity (mm) Relative standard Mingguang deviation of Luoma Lake machine-made Zhongshi river liquidity sand sand sand (RSD, %) Sample 0 min 60 min 0 min 60 min 0 min 60 min 0 min 60 min Example 1 265 195 285 185 289 225 3.75 8.43 Example 2 273 200 292 192 285 226 2.77 7.05 Example 3 270 197 295 183 292 224 3.90 8.45 Example 4 276 203 295 187 300 227 3.56 7.99 Example 5 280 193 294 188 302 229 3.11 8.98 Example 6 281 187 299 190 295 219 2.65 7.26 Example 7 275 192 289 189 295 220 2.93 6.97 Example 8 277 200 291 191 300 225 3.27 7.01 Example 9 275 186 295 193 290 225 2.96 8.43 Example 10 270 189 289 186 294 221 3.64 7.97 Comparative 275 185 221 152 302 234 12.66 17.70 Example 1 Comparative 266 199 216 164 289 220 11.86 11.89 Example 2 Comparative 214 160 176 150 256 210 15.17 15.14 Example 3 Comparative 225 165 205 161 229 183 4.78 5.64 Example 4

(39) It can be seen from the test data in Table 3 that in the three different sand samples, the samples of the examples have the initial fluidity RSD of about 3% and the 60 min fluidity RSD of about 8%; the initial and 60 min fluidity RSDs of Comparative Examples 1-3 are both greater than 11%, much higher than those of the samples in the examples, which indicates that the highly adaptable viscosity-reducing polycarboxylate water reducers of the present invention have strong adaptability to different sand samples. Comparative Example 4 (the low-sensitivity polycarboxylate water reducer synthesized according to the patent) has both initial and 60 min fluidity RSDs being 4-6%, similar to the examples, but the fluidity of the sample of Comparative Example 4 in three different mortars is much less than that of the examples, indicating that Comparative Example 4 has good adaptability to sand samples, but its dispersibility is not competitive compared with the examples.

(40) In summary, the adaptability of the highly adaptable viscosity-reducing polycarboxylate water reducers synthesized in the examples of the present invention to different sands is much stronger than that of conventional polycarboxylate water reducers, and the dispersibility of the highly adaptable viscosity-reducing polycarboxylate water reducers synthesized in the examples is also much higher than that of highly adaptable polycarboxylate water reducer synthesized according to the patent.

Application Example 4

(41) By testing the apparent viscosity of the mortar, the viscosity-reducing performance of the highly adaptive viscosity-reducing polycarboxylate water reducers synthesized in the examples of the present invention was tested. The cement used in the mortar test was Onoda P II 52.5 cement, the sand sample used was ISO standard sand, and the cement-sand ratio was maintained at 0.8. Each water reducer sample was subjected to three parallel tests according to the water-cement ratios of 0.18, 0.20, and 0.22. By adjusting the dosage of water reducers, the initial fluidity of each mortar was kept within 320?5 mm. PXP-I defoamer produced by Jiangsu Subote New Materials Co., Ltd. was used to control the air content of each mortar to be basically the same, so as to ensure the comparability of different mortar samples. The Model R/S SST2000 rheometer produced by Brookfield Company of the United States was used to test the apparent viscosity of each mortar sample, and the results are shown in Table 4. The specific test method can refer to the Reference (Journal of Materials in Civil Engineering, 2016: 04016085).

(42) TABLE-US-00004 TABLE 4 Test results of apparent viscosity of mortar Apparent viscosity of mortar (Pa .Math. s) Water-cement Water-cement Water-cement Sample ratio 0.18 ratio 0.20 ratio 0.22 Example 1 40.5 18.4 6.5 Example 2 43.2 17.9 6.0 Example 3 41.7 16.5 5.8 Example 4 42.5 17.2 6.7 Example 5 42.8 16.4 6.5 Example 6 43.0 15.8 6.6 Example 7 41.9 16.3 7.1 Example 8 41.8 17.1 6.5 Example 9 42.5 16.9 6.0 Example 10 43.0 18.0 7.2 Comparative 60.2 27.9 13.8 Example 1 Comparative 63.5 38.1 14.1 Example 2 Comparative 49.3 21.6 9.6 Example 3 Comparative 66.5 30.5 15.6 Example 4

(43) It can be seen from the test data in Table 4 that when the water-cement ratio is equal to 0.18, the apparent viscosity of the mortar samples of the examples is between 40.5 and 43.2 Pa.Math.s, while Comparative Example 3 (the viscosity-reducing polycarboxylate water reducer synthesized according to the patent) is 49.3 Pa.Math.s, and the apparent viscosity of the other three comparative sample mortars is between 60.2 Pa.Math.s and 66.5 Pa.Math.s, which indicates that the viscosity-reducing performance of the highly adaptable viscosity-reducing polycarboxylate water reducers synthesized in the examples of the present invention is far superior to that of the conventional polycarboxylate water reducers. Although Comparative Example 3 has a certain viscosity-reducing function, the effect is inferior to that of the present invention. The apparent viscosity results of mortars with water-cement ratios of 0.20 and 0.22 have similar conclusions, that is, the viscosities of Examples 1 to 10< the viscosity of Comparative Example 3<the viscosities of Comparative Examples 1, 2, and 4

(44) In summary, the highly adaptable viscosity-reducing polycarboxylate water reducers synthesized in the examples of the present invention have excellent viscosity-reducing function and can effectively reduce the apparent viscosity of cement mortar.

Application Example 5

(45) Next, according to the method specified in GB8076-2008, the viscosity reducing effect of the highly adaptable viscosity-reducing polycarboxylate water reducers of the present invention on high-strength concrete was tested. The cement used in the test was Onoda P II 52.5 cement, the ore powder was S95 ore powder, the fly ash was grade I fly ash, silica fume was Tiankai silica fume with a specific surface area of 16,500 m.sup.2/kg, and sand was Zhongshi river sand with a fineness modulus of 2.7, and the stone was 5-20 mm continuously graded gravel. The test was carried out for 2 groups, which are concrete with strength grades C50 and C100. The mix ratio of C50 concrete is: cement: 368; ore powder: 92; fly ash: 46; sand: 672; stone: 1096; water: 152; and the mix ratio of C100 concrete is: cement: 540: ore powder: 150; silica fume: 60, sand: 620: stone: 930: water: 150. The dosage of the water reducer was adjusted so that the initial slump of the concrete is controlled within 24?0.3 cm, and the air content of the concrete was controlled within 3.5?0.5%, so as to ensure the comparability of the test of each group. The viscosity of concrete is quantified by measuring the empty time of the inverted slump cylinder. The specific method is as follows: the slump cylinder is put upside down and capped at the bottom, filled with concrete and smoothed (generally the inverted slump cylinder is fixed on a bracket, and its bottom is 50 cm above the ground), the bottom cap is slid off quickly to test the empty time of concrete with a stopwatch. The test results of concrete are shown in Table 5.

(46) TABLE-US-00005 TABLE 5 Test results of empty time of concrete sample Empty time of concrete (s) Sample C50 C100 Example 1 9.6 14.3 Example 2 7.3 15.0 Example 3 8.6 15.1 Example 4 7.7 14.6 Example 5 7.2 13.5 Example 6 7.0 12.4 Example 7 6.5 13.3 Example 8 7.5 14.5 Example 9 8.1 15.5 Example 10 9.1 14.0 Comparative 13.6 24.9 Example 1 Comparative 15.2 25.5 Example 2 Comparative 11.2 19.1 Example 3 Comparative 16.4 28.5 Example 4

(47) Based on the statistics of the empty time data of concrete in Table 5, it is found that in C50 concrete, the samples of Examples 1 to 10 have the empty time of 6.5 s to 9.6 s and the average empty time of 7.2 s, while Comparative Examples 1, 2, and 4 have the empty time of 12.4 s to 15.1 s and the average empty time of 13.3 s, and Comparative Example 3 has the empty time of 11.2 s; in C100 concrete, the samples of Examples 1 to 10 have the empty time of 12.4 s to 15.5 s and the average empty time of 14.2 s, while Comparative Examples 1, 2, and 4 have the empty time of 24.9 s and 28.5 s and the average empty time of 26.3 s, and Comparative Example 2 has the empty time of 19.1 s. That is, regardless of C50 or C100 concrete, the empty time comparison result is always as follows: Examples 1 to 10 <Comparative Example 3<Comparative Examples 1, 2, and 4, which is consistent with the test results of the apparent viscosity of the mortar in Application Example 4, indicating that the highly adaptable viscosity-reducing polycarboxylate water reducers synthesized in the examples of the present invention have excellent viscosity-reducing function.