Multitype-adsorptive-group polycarboxylic acid water-reducing agent, method for preparing the same and use thereof

Abstract

The present invention discloses a multitype-adsorptive-group polycarboxylic acid water-reducing agent, consisting of 30-60 wt % of a macromolecule with multitype-adsorptive groups and water, the macromolecule with multitype-adsorptive groups has a polyethylene glycol side chain, and adsorption groups of the polymer backbone include a carboxylic acid group, a sulfonic acid group and a phosphoric acid group, the phosphoric acid group being linked to the backbone of the macromolecule with multitype-adsorptive groups by nucleophilic addition. The water-reducing agent of the present invention has significantly improved adaptability to different cements and aggregates while maintaining a high water reduction efficiency, compared with the conventional polycarboxylic acid water-reducing agent agent. It has a good water reducing efficiency in many different grades of cement, as well as a better resistance to aggregates containing more impurities such as machine-made sand.

Claims

1. A multitype-adsorptive-group polycarboxylic acid water-reducing agent, consisting of 30-60 wt % of a macromolecule with multitype-adsorptive groups and water, wherein the macromolecule with the multitype-adsorptive groups has a polyethylene glycol side chain and a polymer backbone, wherein adsorption groups of the polymer backbone comprise a carboxylic acid group, a sulfonic acid group and a phosphonic acid group, and the phosphonic acid group is linked to the backbone of the macromolecule with the multitype-adsorptive groups by nucleophilic addition, wherein a molecular structure of the macromolecule with the multitype-adsorptive groups has following polymer chain segments: (1) a polymer chain segment comprising at least one structural unit 1 represented by Formula 1: ##STR00008## wherein M.sub.1 is H or Na; (2) a polymer chain segment comprising at least one structural unit 2 represented by Formula 2: ##STR00009## wherein M.sub.2 is H or Na; (3) a polymer chain segment comprising at least one structural unit 4 represented by Formula 4: ##STR00010## wherein M.sub.4 is H or Na; and (4) a polymer chain segment comprising at least one structural unit 5 represented by Formula 5: ##STR00011## wherein R.sub.1 is H or methyl, Y is a C.sub.1-C.sub.4 saturated alkylene group or a C.sub.2?C.sub.5 saturated linear alkyleneoxy group (OC.sub.2?C.sub.5), and P is a number from 15 to 55.

2. The multitype-adsorptive-group polycarboxylic acid water-reducing agent according to claim 1, wherein a molecular weight of the macromolecule with the multitype-adsorptive groups ranges from 20.0 kDa to 35.0 kDa.

3. The multitype-adsorptive-group polycarboxylic acid water-reducing agent according to claim 1, wherein the molecular structure of the macromolecule with the multitype-adsorptive groups has a following polymer chain segment comprising a structural unit 3 represented by Formula 3: ##STR00012## wherein M.sub.3 is H or Na.

4. The multitype-adsorptive-group polycarboxylic acid water-reducing agent according to claim 3, wherein, in every 100 parts by mass of the macromolecule with the multitype-adsorptive groups, a mass ratio of the structural units 1 to 5 is 6-14:2.5-4.5:0-6:16-36:45-75; and in a polymer chain of the macromolecule with the multitype-adsorptive groups, respective structural units are randomly distributed.

5. A method for preparing the multitype-adsorptive-group polycarboxylic acid water-reducing agent according to claim 1, the method comprising: preparing an water-reducing agent intermediate containing a cyano group and a sulfonic group by free radical copolymerization with acrylic acid, 2-acrylamido-2-methylpropanesulfonic acid, maleic anhydride, acrylonitrile and unsaturated polyethylene glycol as raw materials; and performing nucleophilic addition of the cyano group in a molecule of the intermediate and phosphorous acid under catalysis of the sulfonic acid group in the molecule to obtain the multitype-adsorptive-group polycarboxylic acid water-reducing agent.

6. The method according to claim 5, comprising following specific preparation process steps: (1) adding water to 70-85 parts by mass of unsaturated polyethylene glycol E to prepare a solution with a mass concentration of 40-60%; adding an initiator N into the solution, stirring uniformly to obtain a solution I, and then dropwise adding a monomer mixture II and a solution III containing a reductant and a chain transfer agent into the solution I simultaneously at a constant speed at a temperature of 30-60? C., with an addition time for the monomer mixture II being 1-4 hours and an addition time for the solution III being 1.25-5 hours, which is 15-60 min longer then the addition time for the monomer mixture II; after additions, vacuum dehydrating an obtained crude product solution IV at 100? C., cooling, and pulverizing an obtained solid into particles with a diameter smaller than or equal to 0.5 cm to obtain an intermediate V, wherein the monomer mixture II is a mixture of following four types of substances: (1) acrylic acid; (2) 2-acrylamido-2-methylpropanesulfonic acid; (3) maleic anhydride; and (4) acrylonitrile; and (2) taking 80 parts of the intermediate V, adding phosphorous acid, uniformly mixing, heating to 110-150? C., reacting for 8-24 hours, discharging, and adding water to prepare a solution with a mass concentration of 30-60%, during which process sodium hydroxide is added to neutralize a product to obtain the multitype-adsorptive-group polycarboxylic acid water-reducing agent.

7. The method according to claim 6, wherein, in the step (1), the unsaturated polyethylene glycol E has a structure as follows: ##STR00013## wherein definitions or value ranges of R.sub.1, Y, and p are the same as those in the structural unit 5 represented by Formula 5; in the step (1), the initiator N is a water-soluble oxidative free radical polymerization initiator selected from the group consisting of sodium, potassium, and ammonium salts of persulphuric acid, hydrogen peroxide and tert-butyl hydroperoxide, with a molar amount of 1.5%-3.0% of a total molar amount of all monomers in the reaction; in the monomer mixture II, mass ranges of the (1)-(4) monomers are 7-15 parts by mass, 3-5 parts by mass, 0-6 parts by mass and 5-10 parts by mass, respectively; the reductant is a reductant which is reactable with the initiator N in a redox reaction that generates free radicals and is selected from the group consisting of sodium bisulfite, formaldehyde sodium sulfoxylate and ascorbic acid; and a molar amount of the reductant is ?-? of a molar amount of the initiator; the chain transfer agent is a C.sub.2-C.sub.6 water-soluble sulfhydryl compound selected from the group consisting of mercaptoethanol, mercaptopropionic acid and mercaptoacetic acid, and a dosage amount of the chain transfer agent is 1.5-2.5% of a total molar amount of all monomers in the unsaturated polyethylene glycol macromonomer and the monomer mixture II.

8. The method according to claim 6, wherein, in the step (2), a molar amount of phosphorous acid is 2.0-2.5 times a molar amount of acrylonitrile in the step (1).

9. The method according to claim 6, wherein in the step (2), sodium hydroxide is added in a form of a solid or an aqueous solution with a mass concentration of more than 20%, and a molar amount of sodium hydroxide is 30-100% of a total molar amount of acidic hydrogen in all acidic reactants.

10. The method of using the multitype-adsorptive-group polycarboxylic acid water-reducing agent according to claim 1, comprising adding the multitype-adsorptive-group polycarboxylic acid water-reducing agent as a water-reducing agent in portland cement concretes, wherein a solid dosage of the multitype-adsorptive-group polycarboxylic acid water-reducing agent is 0.06 to 0.15% of a mass of a cementitious material.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIGS. 1a-1d show the adaptability of respective examples to different types of concrete and sand: (a) conch cement, different types of sand, slump; (b) Onoda cement, different types of sand, slump; (c) bleeding rate; (d) gas content.

DETAILED DESCRIPTION

(2) The content of the present invention will be further illustrated with examples below, but the content of the present invention is not limited to the following examples. All equivalent changes or modifications made according to the essence of the method of the present invention should be covered within the protection scope of the present invention.

(3) In the examples of the present invention, the molecular weight of the polymer is measured by a gel permeation chromatograph (GPC) of Wyatt Technology Corporation. The experimental was conducted under following conditions: gel column: two series-connected chromatographic columns of Shodex SB806+803; cleaning solution: 0.1M NaNO.sub.3 solution;

(4) Mobile phase velocity: 1.0 mL/min; injection: 20 uL of 0.5% aqueous solution; detector: Shodex RI-71 differential refractive index detector; standard substance: sodium polystyrene sulfonate GPC standard samples (Sigma-Aldrich, molecular weights: 344100, 195800, 108200, 60000, 37500, 28200, 6900, 3000, 1400).

EXAMPLE 1

(5) (1) Water was added to 70 parts by mass of allyl polyethylene glycol E-1 with a weight-average molecular weight of 720 to prepare a solution with a mass concentration of 40%; 3.55 parts by mass of ammonium persulfate was added as an initiator and stirred uniformly to obtain a solution I-1; a mixed solution II-1 containing 15 parts of acrylic acid, 5 parts of 2-acrylamido-2-methylpropanesulfonic acid and 10 parts of acrylonitrile and a solution III-1 containing 0.81 part by mass of sodium bisulfite and 0.55 part by mass of mercaptopropionic acid were added dropwise into the solution I simultaneously at a constant speed at 60? C., with the addition time for the solution II-1 being 2 hours and the addition time for the solution III-1 being 2.5 hours; after addition, an obtained crude product solution IV-1 was vacuum dehydrated at 100? C., and cooled, and an obtained solid was pulverized into particles with a diameter smaller than or equal to 0.5 cm to obtain an intermediate V-1;

(6) (2) 24.8 parts by mass of phosphorous acid was added into 80 parts by mass of the intermediate V-1, uniformly mixed, heated to 110? C., reacted for 16 h and discharged; and water and 7.3 parts by mass of caustic soda flakes were added to neutralize and prepare a solution with a mass concentration of 60%, thus obtaining a multitype-adsorptive-group polycarboxylic acid water-reducing agent P-1 (with a weight-average molecular weight of 2.16?10.sup.4 g/mol, and a conversion rate of 92.2%).

EXAMPLE 2

(7) (1) Water was added to 74 parts by mass of methyl allyl polyethylene glycol E-2 with a weight-average molecular weight of 1200 to prepare a solution with a mass concentration of 45%; 0.73 part by mass of tert-butyl hydroperoxide was added as an initiator and stirred uniformly to obtain a solution I-2; then, a mixed solution II-2 containing 8 parts of acrylic acid, 4 parts of 2-acrylamido-2-methylpropanesulfonic acid, 6 parts of maleic anhydride and 8 parts of acrylonitrile and a solution III-2 containing 0.36 part by mass of ascorbic acid and 0.56 parts by mass of mercaptoacetic acid were added dropwise into the solution I simultaneously at a constant speed at 45? C., with the addition time for the solution II-2 being 1 hour and the addition time for the solution III-2 being 1.25 hours; after addition, an obtained crude product solution IV-2 was vacuum dehydrated at 100? C., and cooled, and an obtained solid was pulverized into particles with a diameter smaller than or equal to 0.5 cm to obtain an intermediate V-2;

(8) (2) 21.8 parts by mass of phosphorous acid was added into 80 parts of the intermediate V-2, uniformly mixed, heated to 120? C., reacted for 8 h and discharged; water and a caustic soda liquid containing 12.8 parts by mass of sodium hydroxide were added to neutralize and prepare a 50% solution, thus obtaining a multitype-adsorptive-group polycarboxylic acid water-reducing agent P-2 (with a weight-average molecular weight of 2.29?10.sup.4 g/mol, and a conversion rate of 88.9%).

EXAMPLE 3

(9) (1) Water was added to 78 parts by mass of methyl butenyl polyethylene glycol E-3 with a weight-average molecular weight of 1600 to prepare a solution with a mass concentration of 50%; 1.19 parts by mass of ammonium persulfate was added as an initiator and stirred uniformly to obtain a solution I-3; then, a mixed solution II-3 containing 12 parts of acrylic acid, 4 parts of 2-acrylamido-2-methylpropanesulfonic acid and 6 parts of acrylonitrile and a solution III-3 containing 0.18 part by mass of sodium bisulfite and 0.74 part by mass of mercaptopropionic acid were added dropwise into the solution I simultaneously at a constant speed at 55? C., with the addition time for the solution II-3 being 3 hours and the addition time for the solution III-3 being 3.5 hours; after addition, an obtained crude product solution IV-3 was vacuum dehydrated at 100? C., and cooled, and an obtained solid was pulverized into particles with a diameter smaller than or equal to 0.5 cm to obtain an intermediate V-3;

(10) (2) 17.5 parts by mass of phosphorous acid was added into 80 parts of the intermediate V-3, uniformly mixed, heated to 135? C., reacted with stirring for 12 h and discharged; water and a caustic soda liquid containing 13.2 parts by mass of sodium hydroxide were added to neutralize and prepare a 40% solution, thus obtaining a multitype-adsorptive-group polycarboxylic acid water-reducing agent P-3 (with a weight-average molecular weight of 2.43?10.sup.4 g/mol, and a conversion rate of 90.9%).

EXAMPLE 4

(11) (1) Water was added to 82 parts by mass of vinyl-4-butoxy polyethylene glycol E-4 with a weight-average molecular weight of 1900 to prepare a solution with a mass concentration of 55%; 0.81 part by mass of 30% hydrogen peroxide was added as an initiator and stirred uniformly to obtain a solution I-4; then, a mixed solution II-4 containing 8 parts of acrylic acid, 4 parts of 2-acrylamido-2-methylpropanesulfonic acid and 6 parts of acrylonitrile and a solution III-4 containing 0.14 part by mass of formaldehyde sodium sulfoxylate and 0.45 part by mass of mercaptoethanol were added dropwise into the solution I simultaneously at a constant speed at 30? C., with the addition time for the solution II-4 being 3.5 hours and the addition time for the solution III-4 being 4 hours; after addition, an obtained crude product solution IV-4 was vacuum dehydrated at 100? C., and cooled, and an obtained solid was pulverized into particles with a diameter smaller than or equal to 0.5 cm to obtain an intermediate V-4;

(12) (2) 17.8 parts by mass of phosphorous acid was added into 80 parts by mass of the intermediate V-4, uniformly mixed, heated to 140? C., reacted with stirring for 20 h and discharged; water and a caustic soda liquid containing 14.3 parts by mass of sodium hydroxide were added to neutralize and prepare a 30% solution, thus obtaining a multitype-adsorptive-group polycarboxylic acid water-reducing agent P-4 (with a weight-average molecular weight of 2.75?10.sup.4 g/mol, and a conversion rate of 91.2%).

EXAMPLE 5

(13) (1) Water was added to 85 parts by mass of vinyl-4-butoxy polyethylene glycol E-5 with a weight-average molecular weight of 2300 to prepare a solution with a mass concentration of 60%; 0.66 part by mass of tert-butyl hydroperoxide was added as an initiator and stirred uniformly to obtain a solution I-5; a mixed solution II-5 containing 8 parts of acrylic acid, 3 parts of 2-acrylamido-2-methylpropanesulfonic acid and 4 parts of acrylonitrile and a solution III-5 containing 0.32 part by mass of ascorbic acid and 0.64 part by mass of mercaptopropionic acid were added dropwise into the solution I simultaneously at a constant speed at 35? C., with the addition time for the solution II-5 being 4 hours and the addition time for the solution III-5 being 5 hours; after addition, an obtained crude product solution IV-5 was vacuum dehydrated at 100? C., and cooled, and an obtained solid was pulverized into particles with a diameter smaller than or equal to 0.5 cm to obtain an intermediate V-5;

(14) (2) 12.4 parts by mass of phosphorous acid was added into 80 parts by mass of V-5, uniformly mixed, heated to 150? C., reacted with stirring for 24 h and discharged; water was added to prepare a 50% solution, thus obtaining a multitype-adsorptive-group polycarboxylic acid water-reducing agent P-5 (with a weight-average molecular weight of 3.11?10.sup.4 g/mol, and a conversion rate of 90.7%).

EXAMPLE 6

(15) (1) Water was added to 80 parts by mass of methyl butenyl polyethylene glycol E-5 with a weight-average molecular weight of 1800 to prepare a solution with a mass concentration of 50%; 1.72 parts by mass of ammonium persulfate was added as an initiator and stirred uniformly to obtain a solution I-6; then, a mixed solution II-6 containing 10 parts of acrylic acid, 5 parts of 2-acrylamido-2-methylpropanesulfonic acid and 5 parts of acrylonitrile and a solution III-6 containing 0.39 part by mass of sodium bisulfite and 0.59 part by mass of mercaptoethanol were added dropwise into the solution I simultaneously at a constant speed at 45? C., with the addition time for the solution II-6 being 2.5 hours and the addition time for the solution III-6 being 3 hours; after addition, an obtained crude product solution IV-6 was vacuum dehydrated at 100? C., and cooled, and an obtained solid was pulverized into particles with a diameter smaller than or equal to 0.5 cm to obtain an intermediate V-6;

(16) (2) 13.6 parts by mass of phosphorous acid was added into 80 parts by mass of the intermediate V-6, uniformly mixed, heated to 135? C., reacted with stirring for 18 h and discharged; water and a caustic soda liquid containing 5.6 parts by mass of sodium hydroxide was added to neutralize and prepare a 50% solution, thus obtaining a multitype-adsorptive-group polycarboxylic acid water-reducing agent P-6 (with a weight-average molecular weight of 2.98?10.sup.4 g/mol, and a conversion rate of 89.5%).

EXAMPLE 7

(17) (1) Water was added to 76 parts by mass of methyl allyl polyethylene glycol E-7 with a weight-average molecular weight of 1500 to prepare a solution with a mass concentration of 45%; 0.83 part by mass of 30% hydrogen peroxide was added as an initiator and stirred uniformly to obtain a solution I-7; then, a mixed solution II-7 containing 13 parts of acrylic acid, 5 parts of 2-acrylamido-2-methylpropanesulfonic acid and 6 parts of acrylonitrile and a solution III-7 containing 0.32 part by mass of ascorbic acid and 0.78 part by mass of mercaptopropionic acid were added dropwise into the solution I simultaneously at a constant speed at 50? C., with the addition time for the solution II-7 being 2 hours and the addition time for the solution III-7 being 2.5 hours; after addition, an obtained crude product solution IV-7 was vacuum dehydrated at 100? C., and cooled, and an obtained solid was pulverized into particles with a diameter smaller than or equal to 0.5 cm to obtain an intermediate V-7;

(18) (2) 18.2 parts by mass of phosphorous acid was added into 80 parts by mass of the intermediate V-7, uniformly mixed, heated to 120? C., reacted with stirring for 12 h and discharged; water and a caustic soda liquid containing 10.3 parts by mass of sodium hydroxide was added to neutralize and prepare a 50% solution, thus obtaining a multitype-adsorptive-group polycarboxylic acid water-reducing agent P-7 (with a weight-average molecular weight of 2.70?10.sup.4 g/mol, and a conversion rate of 90.1%).

EXAMPLE 8

(19) (1) Water was added to 76 parts by mass of methyl allyl polyethylene glycol E-8 with a weight-average molecular weight of 1500 to prepare a solution with a mass concentration of 50%; 0.80 part by mass of 30% hydrogen peroxide was added as an initiator and stirred uniformly to obtain a solution I-8; then, a mixed solution II-8 containing 9 parts of acrylic acid, 5 parts of 2-acrylamido-2-methylpropanesulfonic acid, 4 parts by mass of maleic anhydride and 6 parts of acrylonitrile and a solution III-8 containing 0.18 part by mass of formaldehyde sodium sulfoxylate and 0.75 part by mass of mercaptopropionic acid were added dropwise into the solution I simultaneously at a constant speed at 50? C., with the addition time for the solution II-8 being 2 hours and the addition time for the solution III-8 being 2.5 hours; after addition, an obtained crude product solution IV-8 was vacuum dehydrated at 100? C., and cooled, and an obtained solid was pulverized into particles with a diameter smaller than or equal to 0.5 cm to obtain an intermediate V-8;

(20) (2) 15.6 parts by mass of phosphorous acid was added into 80 parts by mass of the intermediate V-8, uniformly mixed, heated to 125? C., reacted with stirring for 12 h and discharged; water and a caustic soda liquid containing 12.3 parts by mass of sodium hydroxide was added to neutralize and prepare a 50% solution, thus obtaining a multitype-adsorptive-group polycarboxylic acid water-reducing agent P-8 (with a weight-average molecular weight of 2.57?10.sup.4 g/mol, and a conversion rate of 88.7%).

COMPARATIVE EXAMPLE 1

(21) In this comparative example, in order to illustrate the necessity of phosphonic acid structural units in the water-reducing agent of the present invention for improving the efficiency of the water-reducing agent, acrylonitrile was equimolarly replaced with acrylic acid, and the subsequent phosphonation step was omitted. The process of this comparative example was based on the process of Example 3: water was added to 78 parts by mass of methyl butenyl polyethylene glycol E-r1 with a weight-average molecular weight of 1600 to prepare a solution with a mass concentration of 50%; 1.19 parts by mass of ammonium persulfate was added as an initiator and stirred uniformly to obtain a solution I-r1; then, a mixed solution II-r1 containing 20.2 parts of acrylic acid and 4 parts of 2-acrylamido-2-methylpropanesulfonic acid and a solution III-r1 containing 0.18 part by mass of sodium bisulfite and 0.74 part by mass of mercaptopropionic acid were added dropwise into the solution I simultaneously at a constant speed at 55? C., with the addition time for the solution II-r1 being 3 hours and the addition time for the solution III-r1 being 3.5 hours; after addition, a caustic soda liquid containing 9.6 parts by mass of sodium hydroxide was added to neutralize, thus obtaining a water-reducing agent P-r1 (with a weight-average molecular weight of 2.29?10.sup.4 g/mol, and a conversion rate of 92.0%).

COMPARATIVE EXAMPLE 2

(22) In this comparative example, in order to illustrate the superiority of the preparation method of the phosphonic acid structural units of the present invention in the efficacy of the obtained water-reducing agent over other phosphonic acid monomers, acrylonitrile was equimolarly replaced with a typical phosphoric acid-based monomer, 2-hydroxyethyl methacrylate phosphate, and the subsequent phosphonation step was omitted. The process of this comparative example was based on Example 3:

(23) (1) Water was added to 78 parts by mass of methyl butenyl polyethylene glycol E-r2 with a weight-average molecular weight of 1600 to prepare a solution with a mass concentration of 50%; 1.19 parts by mass of ammonium persulfate was added as an initiator and stirred uniformly to obtain a solution I-r2; then, a mixed solution II-r2 containing 12 parts of acrylic acid, 4 parts of 2-acrylamido-2-methylpropanesulfonic acid, and 25.8 parts by mass of 2-hydroxyethyl methacrylate phosphate and a solution III-r2 containing 0.18 part by mass of sodium bisulfite and 0.74 part by mass of mercaptopropionic acid were added dropwise into the solution I simultaneously at a constant speed at 55? C., with the addition time for the solution II-r2 being 3 hours and the addition time for the solution III-r2 being 3.5 hours; after addition, a caustic soda liquid containing 9.6 parts by mass of sodium hydroxide was added to neutralize, thus obtaining a water-reducing agent P-r2 (with a weight-average molecular weight of 2.55?10.sup.4 g/mol, and a conversion rate of 88.7%).

COMPARATIVE EXAMPLE 3

(24) This comparative example is a typical synthesis process of an ester-type polycarboxylic acid water-reducing agent, for the purpose of comparing the efficacy of the examples with that of a typical ester-type polycarboxylic acid water-reducing agent.

(25) 120 parts by mass of methoxy polyethylene glycol (Mw=1200), 10 parts by mass of methacrylic acid, 0.6 part by mass of p-toluenesulfonic acid, 0.05 part by mass of phenothiazine and 16 parts by mass of toluene were added into a reflux reactor with a water separation device, heated and refluxed at 130? C. until more than 1.75 parts by mass of water was discharged, and the toluene was removed under reduced pressure to obtain a methoxy polyethylene glycol (1200) methacrylate macromonomer.

(26) In the reactor, 60 parts of water and 0.65 part by mass of hydrogen peroxide were added and stirred uniformly to obtain a solution I-r1. At the same time, 65 parts by mass of methoxypolyethylene glycol (1000) methacrylate, 16.5 parts by mass of methacrylic acid, 0.25 part by mass of vitamin C and 0.60 part by mass of mercaptopropionic acid were uniformly mixed to obtain a solution II-r3, and the solution II-r3 was dropwise added into the solution I-r3 at a constant speed at 40? C. under the protection of nitrogen over an addition time of 2.5 h; the reaction was continued for 1 h at 40? C., and the pH of the obtained solution was adjusted to 5-6 by a caustic soda liquid after the reaction was completed to obtain the ester-type polycarboxylic acid water-reducing agent P-r3 of the comparative example (Mw=2.22?10.sup.4, with a conversion rate of 92.3%).

COMPARATIVE EXAMPLE 4

(27) This comparative example is a typical synthesis process of an ether-type polycarboxylic acid water-reducing agent, for the purpose of comparing the efficacy of the examples with that of a typical ether-type polycarboxylic acid water-reducing agent.

(28) In a reactor, 80 parts by mass of methyl allyl polyethylene glycol (2000), 80 parts by mass of water and 0.60 part by mass of 30% hydrogen peroxide were added and mixed evenly to obtain a solution I-r4, and 0.26 part by mass of ascorbic acid, 0.64 part by mass of mercaptopropionic acid and 49.1 parts by mass of water were mixed to obtain a solution II-r4. Under that protection of nitrogen at 45? C., the solution II-r4 and 14.4 parts by mass of acrylic acid were added dropwise simultaneously into the solution I-r4 at a constant speed, with the dropwise addition time of II-r4 being 3 h, the dropwise addition time of acrylic acid being 2.5 h; then reaction was continued at 45? C. for 1 h. After the reaction was completed, the pH of the obtained solution was adjusted to 5-6 by using a caustic soda liquid to obtain the ether-type polycarboxylic acid water-reducing agent P-r4 of the comparative example. (Mw=2.69?10.sup.4, with a conversion rate of 89.7%).

(29) Performance Evaluation of the Examples

(30) Cement Paste Fluidity Test

(31) The dispersion effects of various cements of the embodiments of the present invention were first evaluated in a paste fluidity test. The test procedure was in accordance with GB/T8077-2000 Standard. 300 g cement was used, and a water-cement ratio is 0.29 in the test. The cements used were reference cement (P.I. 42.5), Onoda cement (P. II. 52.5), Helin cement (P.O. 42.5), Conch cement (P.O. 42.5), and Zhongshan cement (P.O. 42.5). The cement components were quantitatively determined by XRD. All tests were carried out at 20? C., and the dosage of the water-reducing agent used in the paste fluidity test was 0.10%.

(32) TABLE-US-00001 TABLE 1 Type and composition of the cement used in evaluation experiment of the examples XRD quantification Cement Type C3S C2S C3A C4AF limestone gypsum Reference cement P.I. 42.5 57.3 17.0 8.5 7.3 <0.1 5.3 Onoda cement P. II.52.5 55.9 15.8 6.8 6.4 3.3 6.0 Conch cement P.O.42.5 49.7 13.1 6.1 4.6 4.0 5.8 Helin cement P.O. 42.5 45.3 14.2 5.3 4.2 1.2 5.5 Zhongshan cement P.O. 42.5 50.6 14.5 6.4 5.0 2.8 6.1

(33) TABLE-US-00002 TABLE 2 Water reducing efficiency of various examples and comparative examples ondifferent types of cement pastes Reference Onoda Conch Helin Zhongshan cement cement cement cement cement Example 4 min 60 min 4 min 60 min 4 min 60 min 4 min 60 min 4 min 60 min P-1 212 214 238 240 219 224 200 197 212 215 P-2 221 217 248 246 234 234 213 204 224 223 P-3 239 228 266 259 254 248 233 216 247 240 P-4 217 207 241 232 225 220 204 190 223 217 P-5 228 214 252 238 239 231 217 198 229 220 P-6 226 212 254 240 236 228 221 202 229 220 P-7 230 219 261 251 243 238 220 205 241 235 P-8 234 224 257 247 247 237 226 210 233 227 P-r1 193 158 208 177 197 178 178 148 188 170 P-r2 187 183 216 207 209 201 188 176 203 198 P-r3 193 156 213 181 198 178 185 154 196 176 P-r4 213 163 240 204 205 183 204 170 202 188

(34) The above results show that the initial fluidity of the reference cement and Onoda cement with a lower filler content using each example was generally superior to that using the typical conventional water-reducing agents in comparative examples 3 and 4, P-1 has relatively lower efficacy among the examples, and P-r4 was substantially equivalent to P-1 in efficacy. However, all examples behaved better than P-r4 and P-r3 in the three P.O.42.5 cements with a higher admixture content. Among the various examples, the effects of examples 3, 7, and 8 have better effects. The reasons for the overall better efficacy performance of the examples are that the water-reducing agents in the examples contain phosphonated groups with higher calcium ion complexing ability, which form a gradient supplement of complexing activity with carboxyl sulfonic acid groups, thereby better adapting to the microscopic characteristics (such as components, surface activity and the like) of different cements and admixtures and thus showing a better macroscopic performance.

(35) Meanwhile, the above results show that the comparative example P-r1 lacking a phosphonic acid group and the P-r2 of the test ester-type phosphonic acid monomer were both much less effective than the examples, which demonstrates the necessity of the structural characteristics and the preparation process of the water-reducing agents of the present invention for ensuring the effects thereof.

(36) Thereafter, that adaptability of the above admixture was further tested by the above tests of fluidity and bleeding rate of different types of concrete, and the results are shown in the following table. In the test, Onoda cement and Conch cement with representative difference in composition among the above cements were selected, and the river sand and machine-made sand were selected for the sand. In addition to the above materials, grades of other materials were all in accordance with the GB8076-2008 standard, and the proportion of the concrete was also designed based on this standard, as shown in the following table. The bleeding rate test procedure was in accordance with GB50080-2016. Sine there are many variables in the test, P-1, P-3 and P-8, which were more representative in efficacies in the above examples, and P-r3 and P-r4, which were compared as conventional water-reducing agents, were selected and tested. In the test, the solid dosage of each example was 0.15%. The mixing ratio of the concrete was designed as follows.

(37) TABLE-US-00003 TABLE 3 Concrete mixing proportion used in the test Cement Water Sand Pebble Boulder 360 150 820 408 612

(38) TABLE-US-00004 TABLE 4 Basic parameters of sand used in the test fineness Sand Silt content modulus Clean river sand <1.0 2.78 Machine-made sand 3.1 2.82

(39) For the experimental results of the adaptability of each example to different types of concrete and sand, see FIG. 1 of the specification. The three typical examples P-1, P-3 and P-8 all show relatively stable efficacy performance, superior to the comparative P-r3 and P-r4, and the cement dispersion performance and the air content and bleeding rate of the obtained concrete are less affected by the type of the cement and the quality of the sand material; the comparative P-r3 and P-r4 can still show a slightly lower efficacy in the river sand concrete system with fewer impurities than the examples, but when the sand material is replaced with the machine-made sand with a certain silt content, the slump, bleeding rate and air content indexes of the P-r3 and P-r4 worsened drastically, which is significantly different from the examples, verifying the good adaptability of the examples of the present invention to cements and aggregates, as well as the tolerance to clay. This adaptability stems from the diversified distribution of the adsorption groups of calcium complexing activity represented by the phosphonic acid group on its backbone. In addition, although Example 1 showed a smaller efficacy in that above paste fluidity test than the other examples, in this round of testing, due to its shorter polyethylene glycol chain and relatively high phosphonic acid group content, it showed better tolerance to machine-made sand having a certain silt content than Examples 3 and 8, which objectively confirms the necessity of the value range of the chain length of the unsaturated polyethylene glycol monomer according to the present invention.