CN112661914A - Novel polycarboxylate superplasticizer special for machine-made sand and preparation method thereof - Google Patents
Novel polycarboxylate superplasticizer special for machine-made sand and preparation method thereof Download PDFInfo
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Abstract
The invention discloses a novel polycarboxylate superplasticizer special for machine-made sand and a preparation method thereof. The novel polycarboxylate superplasticizer special for machine-made sand is prepared by polymerizing a polyether macromonomer, a dopamine modified polyether macromonomer, unsaturated carboxylic acid, unsaturated carboxylic ester and a dopamine monomer. According to the invention, the functional group catechol group with the most effective mussel protein adhesion is introduced into the macromolecular structure, so that the adhesion capability of water reducing agent molecules on the cleavage surface with low surface energy of the machine-made sand is effectively enhanced, the slurry can be reduced in viscosity and thickened, and the purposes of reducing bleeding and effectively improving the workability and uniformity of concrete mixtures are achieved. And because the catechol group can also form better coordination and hydrogen bond interaction on the surface of the sand, the integral uniformity of the mixture and the mechanical property and durability after molding can be effectively improved.
Description
Technical Field
The invention belongs to the field of high polymer materials, and particularly relates to a novel polycarboxylate superplasticizer special for machine-made sand and a preparation method thereof.
Background
With the improvement of the domestic economic level and the unprecedented development of the civil engineering construction industry, the construction scale is increasingly large. As one of the most important construction engineering materials, the preparation technology of high performance concrete is also continuously developed. The chemical admixture, especially the water reducing agent, is one of important guarantees of the performance of high-performance concrete, wherein the polycarboxylic acid water reducing agent has been widely applied to the concrete due to the advantages of low mixing amount, high water reducing rate, good slump retaining performance, low shrinkage, large modification potential and the like, and replaces the traditional lignosulfonate and naphthalene water reducing agents to become main products in the current water reducing agent market. In the concrete raw material, because natural sand resources in China are exhausted day by day, and in order to protect the ecological environment, river flood banks, shipping and the use safety of bridges, the exploitation of the natural sand is limited day by day, the yield is tense day by day, and the price is expensive. Machine-made sand aggregate made by machine crushing and screening has gradually replaced natural sand to become a main construction sand source. According to statistics, the using amount of the machine-made sand in the concrete fine aggregate in China in 2002 is less than 10%, and the proportion of the machine-made sand reaches 76% by 2013, and is more than 80% at present. It can be seen that the use of machine-made sand as fine aggregate is certainly a mainstream direction in concrete development.
The machine-made sand is greatly different from the natural sand in performance, and the quality of the machine-made sand is in a relatively unstable state due to differences of regional mother rocks, production equipment, production processes and the like. For machine-made sand made of parent rocks such as basalt or iron tailings and the like, because a cleavage surface with lower surface energy is formed in the preparation process, slurry is weaker in adhesion on the surface of the machine-made sand, and in addition, because the machine-made sand is poor in particle size distribution and high in stone powder content, the cohesiveness, the workability and the workability of a concrete mixture are poor, and the mechanical property and the durability of a concrete product are also influenced.
Mussel is a marine organism and can be attached to the surface of the reef through secreting mussel protein, and research shows that the mussel protein has good adhesion capacity to various substrate surfaces including polytetrafluoroethylene with low surface energy. And DOPA containing catechol side group plays an important role in the adhesion performance, so that the introduction of catechol group into high polymer to obtain the polymer containing side chain or terminal catechol group is the most effective means for developing functional material based on the adhesion characteristic of mussel protein.
There are some admixtures suitable for machine-made sand concrete. Patent CN109796149A discloses a thickening water reducer for machine-made sand concrete, which is prepared from a reactive air-entraining agent, a reactive thickener, a powdery polycarboxylate water reducer and fly ash as raw materials, and can be used for improving the working performance of the machine-made sand concrete. Patent CN109627394A discloses a polycarboxylate concrete water reducing agent which is prepared by introducing a high surface active monomer 2-acrylamido dodecyl sulfonic acid and is suitable for machine-made sand, and the polycarboxylate concrete water reducing agent can improve the wettability of the polycarboxylate water reducing agent to the machine-made sand and improve the air entraining effect. Patent CN108359064A discloses a polycarboxylic acid water reducing agent prepared by introducing cationic starch ether, which can be used for coarse sand of graded composition.
The effect of the machine-made sand water reducing agent prepared by the prior art is not obvious, and is often accompanied with the problems of difficult use and unstable effect, so that the machine-made sand water reducing agent with higher adaptability is researched, and the machine-made sand water reducing agent has important significance for the whole industry.
Disclosure of Invention
The invention aims to solve the problems and provides a novel polycarboxylate superplasticizer special for machine-made sand and a preparation method thereof.
The novel polycarboxylate superplasticizer special for machine-made sand is a high-molecular polymer solution obtained by polymerizing a polyether macromonomer, a dopamine modified polyether macromonomer, unsaturated carboxylic acid, unsaturated carboxylic ester and a dopamine monomer in the presence of an initiator and a chain transfer agent.
The molar ratio of the polyether macromonomer to the dopa-modified polyether macromonomer to the unsaturated carboxylic acid ester to the dopamine monomer is 1: (0.2-0.8): (1.5-6): (0.5-2): (0.2-0.8).
The polyether macromonomer is at least one of isobutylene polyglycol ether (HPEG), prenol polyglycol ether (TPEG), Allyl Polyglycol Ether (APEG) and ethylene glycol monovinyl Ether Polyoxyethylene Ether (EPEG) with the molecular weight of 1800-3000, the unsaturated carboxylic acid is at least one of acrylic acid, methacrylic acid, fumaric acid and itaconic acid, and the unsaturated carboxylic acid ester is at least one of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxybutyl acrylate and hydroxypropyl methacrylate.
The novel polycarboxylate superplasticizer special for machine-made sand is characterized in that the molecular weight of the dopa modified polyether macromonomer is 1600-2400, and the structure is as follows:
wherein p = 1-3; when n =1, the modified poly (isobutylene) glycol ether is dopa, and when n =2, the modified poly (isopentenol) glycol ether is dopa.
The dopamine monomer is at least one of dopamine methacrylamide, dopamine acrylamide, dopamine methacrylamide and dopamine acrylamide.
The initiator is at least one of potassium persulfate, ammonium persulfate, azodiisopropyl amidine oxazoline hydrochloride, azodiisobutymidine dihydrochloride, a hydrogen peroxide-ascorbic acid initiation system, a hydrogen peroxide-rongalite initiation system and an ammonium persulfate-sodium sulfite initiation system, the dosage of the initiator is 0.3-3% of the dosage of the monomers, and the chain transfer agent is at least one of mercaptoethanol, mercaptoacetic acid, mercaptopropionic acid, mercaptopropanol, sodium hypophosphite, trisodium phosphate and CTA1420, and the dosage of the chain transfer agent is 0.2-2% of the dosage of the monomers.
The preparation method of the special novel polycarboxylate superplasticizer for machine-made sand comprises the following steps: adding a polyether macromonomer, a dopamine modified polyether macromonomer and water into a reaction container to be dissolved uniformly, respectively dropwise adding a polymerization monomer solution (containing unsaturated carboxylic acid, unsaturated carboxylic ester and dopamine monomer) and an initiator solution (containing initiator and chain transfer agent) into a reaction bottle under the stirring condition, preserving heat after dropwise adding is finished, continuously reacting to obtain a polymerization product solution, and adding a proper amount of alkali into the polymerization product solution to adjust the pH value to obtain the novel polycarboxylate superplasticizer special for machine-made sand.
The reaction temperature of the polymerization reaction is 18-70 ℃, the dropping time of the polymerization monomer solution and the initiator solution is 1.5-3 hours and 2-3.5 hours respectively, the dropping time of the polymerization monomer solution is less than that of the initiator solution, the heat preservation time is 1-3.5 hours, and the alkali is at least one of sodium hydroxide, potassium hydroxide, triethylamine and triethanolamine or an aqueous solution thereof.
The novel polycarboxylate superplasticizer special for machine-made sand can be used as a water reducer or a concrete regulator of machine-made sand.
The novel polycarboxylate superplasticizer special for machine-made sand and the preparation method thereof have the positive effects that:
compared with the existing water reducing agent, the novel polycarboxylate water reducing agent special for machine-made sand prepared by the method introduces catechol groups into the side chains of macromolecules through the polymerization of the dopa modified polyether macromonomer and the dopamine monomer. When the comb-shaped macromolecule is dispersed in cement paste, the comb-shaped macromolecule has a side chain containing a catechol group, so that the cement paste is easily adsorbed on the cleavage surface of the machine-made sand with low surface energy, and the workability of concrete is effectively improved.
Because only the macromonomer and the modified monomer with lower molecular weight are used for tackifying to increase adhesion without using the macromonomer with higher molecular weight, the slurry viscosity of the machine-made sand with high stone powder content can be effectively reduced. In addition, because the catechol group can be combined with metal ions in concrete, the catechol group can also form better coordination action and hydrogen bond interaction on the surface of sand, so that the integral uniformity of the mixture and the mechanical property and durability of a formed product can be effectively improved.
Detailed Description
The present invention will be described in further detail with reference to specific examples.
Example 1: a novel polycarboxylate superplasticizer special for machine-made sand is prepared by the following preparation process
Adding 85g of isobutenol polyglycol ether with the molecular weight of 2400 and 30g of dopa modified isobutenol polyglycol ether with the molecular weight of 1800 into a reaction vessel containing 100g of water, stirring and dissolving, dropwise adding a polymerization monomer solution (containing 12g of acrylic acid, 6g of hydroxyethyl acrylate, 6g of dopamine methacrylamide, 30g of water) and an initiator solvent (containing 1g of potassium persulfate, 2g of mercaptopropionic acid and 20g of water) into the reaction vessel for reaction, wherein the reaction temperature is 65 ℃, the dropwise adding time is 2 hours and 2.5 hours respectively, and preserving heat for 2 hours after the dropwise adding is finished to obtain a copolymerization product. Adding 35% of sodium hydroxide aqueous solution by mass fraction to neutralize until the pH value is about 6, and obtaining the novel polycarboxylate superplasticizer special for machine-made sand.
Example 2: a novel polycarboxylate superplasticizer special for machine-made sand is prepared by the following preparation process
Adding 85g of isobutenol polyglycol ether with the molecular weight of 2400 and 30g of dopa modified isobutenol polyglycol ether with the molecular weight of 1800 into a reaction vessel containing 100g of water, stirring and dissolving, dropwise adding a polymerization monomer solution (containing 12g of acrylic acid, 6g of hydroxyethyl acrylate, 1.8g of dopamine methacrylamide and 30g of water) and an initiator solvent (containing 1g of potassium persulfate, 2g of mercaptopropionic acid and 20g of water) into the reaction vessel for reaction, wherein the reaction temperature is 65 ℃, the dropwise adding time is 2 hours and 2.5 hours respectively, and preserving heat for 2 hours after the dropwise adding is finished to obtain a copolymerization product. Adding 35% of sodium hydroxide aqueous solution by mass fraction to neutralize until the pH value is about 6, and obtaining the novel polycarboxylate superplasticizer special for machine-made sand.
Example 3: a novel polycarboxylate superplasticizer special for machine-made sand is prepared by the following preparation process
Adding 80g of prenol polyglycol ether with the molecular weight of 2000, 35g of dopa modified prenol polyglycol ether with the molecular weight of 2000 and 1.5g of hydrogen peroxide solution into a reaction vessel containing 100g of water, stirring and dissolving, dropwise adding a polymerization monomer solution (containing 10g of methacrylic acid, 8g of hydroxypropyl acrylate, 7g of dopa methacrylamide and 30g of water) and an initiator solvent (containing 0.4g of ascorbic acid, CTA14201.8g and 20g of water) into the reaction vessel for reaction, wherein the reaction starting temperature is 22 ℃, the dropwise adding time is 2.5h and 3h respectively, and preserving heat for 1.5h after the dropwise adding is finished to obtain a copolymerization product. Adding 35% of potassium hydroxide aqueous solution by mass fraction for neutralization until the pH value is about 6, and obtaining the novel polycarboxylate superplasticizer special for machine-made sand.
Example 4: a novel polycarboxylate superplasticizer special for machine-made sand is prepared by the following preparation process
Adding 80g of allyl polyglycol ether with the molecular weight of 2000 and 28g of dopa-modified prenol polyglycol ether with the molecular weight of 1800 into a reaction container containing 100g of water, stirring for dissolving, dropwise adding a polymerization monomer solution (containing 7.5g of acrylic acid, 7.5g of fumaric acid, 4g of hydroxyethyl methacrylate, 6g of dopamine acrylamide and 30g of water) and an initiator solvent (containing 1.2g of ammonium persulfate, 1.5g of mercaptoethanol and 20g of water) into the reaction container for reaction, wherein the reaction temperature is 68 ℃, the dropwise adding time is 1.5h and 2h respectively, and preserving heat for 2h after the dropwise adding is finished to obtain a copolymerization product. Adding triethanolamine to neutralize until the pH value is about 6, and obtaining the special novel polycarboxylate superplasticizer for machine-made sand.
Example 5: a novel polycarboxylate superplasticizer special for machine-made sand is prepared by the following preparation process
Adding 90g of ethylene glycol monovinyl ether polyoxyethylene ether with the molecular weight of 2400, 27g of dopa modified isobutylene glycol polyethylene glycol ether with the molecular weight of 1800 and 1.25g of hydrogen peroxide solution into a reaction container containing 100g of water, stirring and dissolving, dropwise adding a polymerization monomer solution (containing 7g of acrylic acid, 7g of itaconic acid, 2g of hydroxyethyl acrylate, 3g of hydroxypropyl methacrylate, 5.5g of dopamine acrylamide and 30g of water) and an initiator solvent (containing 0.5g of sodium formaldehyde sulfoxylate, 2.8g of sodium hypophosphite and 20g of water) into the reaction container for reaction, wherein the reaction starting temperature is 20 ℃, the dropwise adding time is 1h and 1.5h respectively, and preserving heat for 1.5h after the dropwise adding is finished to obtain a copolymerization product. Adding triethylamine to neutralize until the pH value is about 6, and obtaining the special novel polycarboxylate superplasticizer for machine-made sand.
Example 6: a novel polycarboxylate superplasticizer special for machine-made sand is prepared by the following preparation process
Adding 80g of prenol polyglycol ether with the molecular weight of 2400 and 42g of dopa-modified prenol polyglycol ether with the molecular weight of 2400 into a reaction container containing 100g of water, stirring to dissolve, dropwise adding a polymerization monomer solution (containing 13g of acrylic acid, 6g of hydroxybutyl acrylate, 4.7g of dopa-methacrylamide, 30g of water) and an initiator solvent (containing 1g of azobisisobutyramidine dihydrochloride, 1.6g of mercaptopropionic acid and 20g of water) into the reaction container to react, wherein the reaction temperature is 60 ℃, the dropwise adding time is 2 hours and 2.5 hours respectively, and preserving heat for 2.5 hours after the dropwise adding is finished to obtain a copolymerization product. Adding 35% of sodium hydroxide aqueous solution by mass fraction to neutralize until the pH value is about 6, and obtaining the novel polycarboxylate superplasticizer special for machine-made sand.
Example 7: a novel polycarboxylate superplasticizer special for machine-made sand is prepared by the following preparation process
65g of prenol polyglycol ether with the molecular weight of 2400, 38g of isobutenol polyglycol ether with the molecular weight of 1800 and 38g of dopa-modified isobutenol polyglycol ether with the molecular weight of 2000 are added into a reaction vessel containing 100g of water and stirred for dissolution, a polymerization monomer solution (containing 8.5g of methacrylic acid, 7g of itaconic acid, 2.5g of hydroxypropyl acrylate, 3.5g of hydroxybutyl methacrylate, 6.5g of dopamine methacrylamide and 30g of water), an initiator solvent (containing 1g of azodiisopropylamidine oxazoline hydrochloride, 1.2g of mercaptopropanol and 20g of water) are dropwise added into the reaction vessel for reaction, the reaction temperature is 62 ℃, the dropwise adding time is 1.5h and 2h respectively, and after the dropwise adding is finished, the temperature is kept for 3h, so that a copolymerization product is obtained. Adding 35% of potassium hydroxide aqueous solution by mass fraction for neutralization until the pH value is about 6, and obtaining the novel polycarboxylate superplasticizer special for machine-made sand.
Comparative example 1: conventional polycarboxylic acid water reducing agent
Adding 85g of isobutylene polyglycol ether with the molecular weight of 2400 and 30g of isobutylene polyglycol ether with the molecular weight of 1800 into a reaction vessel containing 100g of water, stirring for dissolving, dropwise adding a polymerization monomer solution (containing 12g of acrylic acid, 6g of hydroxyethyl acrylate and 30g of water) and an initiator solvent (containing 1g of potassium persulfate, 2g of mercaptopropionic acid and 20g of water) into the reaction vessel for reaction at the reaction temperature of 65 ℃ for 2 hours and 2.5 hours respectively, and preserving heat for 2 hours after the dropwise adding is finished to obtain a copolymerization product. Adding 35% of sodium hydroxide aqueous solution by mass fraction to neutralize until the pH value is about 6, and obtaining the conventional polycarboxylic acid water reducing agent.
Comparative example 2: conventional polycarboxylic acid water reducing agent
115g of prenol polyglycol ether with the molecular weight of 2000 and 1.5g of hydrogen peroxide solution are added into a reaction vessel containing 100g of water to be stirred and dissolved, a polymerization monomer solution (containing 10g of methacrylic acid, 8g of hydroxypropyl acrylate and 30g of water) and an initiator solvent (containing 0.4g of ascorbic acid, CTA14201.8 g and 20g of water) are dropwise added into the reaction vessel to react, the reaction starting temperature is 22 ℃, the dropwise adding time is 2.5h and 3h respectively, and the temperature is kept for 1.5h after the dropwise adding is finished, so that a copolymerization product is obtained. Adding 35% of potassium hydroxide aqueous solution by mass fraction for neutralization until the pH value is about 6, and obtaining the conventional polycarboxylic acid water reducing agent.
Comparative example 3: polycarboxylic acid water reducing agent
Adding 85g of isobutenol polyglycol ether with the molecular weight of 2400 and 30g of dopa modified isobutenol polyglycol ether with the molecular weight of 1800 into a reaction vessel containing 100g of water, stirring and dissolving, dropwise adding a polymerization monomer solution (containing 12g of acrylic acid, 6g of hydroxyethyl acrylate, 8g of dopamine methacrylamide, 30g of water) and an initiator solvent (containing 1g of potassium persulfate, 2g of mercaptopropionic acid and 20g of water) into the reaction vessel for reaction, wherein the reaction temperature is 65 ℃, the dropwise adding time is 2 hours and 2.5 hours respectively, and preserving heat for 2 hours after the dropwise adding is finished to obtain a copolymerization product. Adding 35% of sodium hydroxide aqueous solution by mass fraction to neutralize until the pH value is about 6, and obtaining the novel polycarboxylate superplasticizer special for machine-made sand.
Comparative example 4: polycarboxylic acid water reducing agent
Adding 40g of prenol polyglycol ether with the molecular weight of 2400 and 82g of dopa-modified prenol polyglycol ether with the molecular weight of 2400 into a reaction container containing 100g of water, stirring to dissolve, dropwise adding a polymerization monomer solution (containing 13g of acrylic acid, 6g of hydroxybutyl acrylate and 30g of water) and an initiator solvent (containing 1g of azobisisobutyramidine dihydrochloride, 1.6g of mercaptopropionic acid and 20g of water) into the reaction container to react at the temperature of 60 ℃ for 2h and 2.5h respectively, and preserving heat for 2.5h after dropwise adding is finished to obtain a copolymerization product. Adding 35% of sodium hydroxide aqueous solution by mass fraction to neutralize until the pH value is about 6, and obtaining the polycarboxylic acid water reducing agent.
Comparative example 5: polycarboxylic acid water reducing agent
Adding 122g of prenol polyglycol ether with the molecular weight of 2400 into a reaction container containing 100g of water, stirring and dissolving, dropwise adding a polymerization monomer solution (containing 13g of acrylic acid, 6g of hydroxybutyl acrylate, 9.4g of dopa methacrylamide and 30g of water) and an initiator solvent (containing 1g of azobisisobutyramidine dihydrochloride, 1.6g of mercaptopropionic acid and 20g of water) into the reaction container for reaction, wherein the reaction temperature is 60 ℃, the dropwise adding time is 2 hours and 2.5 hours respectively, and preserving heat for 2.5 hours after the dropwise adding is finished to obtain a copolymerization product. Adding 35% of sodium hydroxide aqueous solution by mass fraction to neutralize until the pH value is about 6, and obtaining the polycarboxylic acid water reducing agent.
Description of the effects:
the method comprises the steps of measuring the net slurry flow by using the novel polycarboxylate water reducer special for machine-made sand and the comparative polycarboxylate water reducer according to GB/T8077-. The test results are shown in Table 1.
TABLE 1 Cement paste fluidity test results
| Sample (I) | Fluidity of outlet machine (mm) | Yield stress (Pa) | Plastic viscosity (Pa s) |
| Example 1 | 240 | 25.68 | 2.86 |
| Example 2 | 235 | 21.79 | 2.61 |
| Example 3 | 237 | 23.65 | 2.75 |
| Example 4 | 243 | 23.44 | 2.69 |
| Example 5 | 245 | 24.31 | 2.70 |
| Example 6 | 240 | 20.22 | 2.55 |
| Example 7 | 238 | 22.71 | 2.64 |
| Comparative example 1 | 235 | 16.51 | 3.31 |
| Comparative example 2 | 242 | 17.93 | 3.53 |
| Comparative example 3 | 243 | 18.92 | 3.69 |
| Comparative example 4 | 236 | 18.69 | 3.15 |
| Comparative example 5 | 233 | 17.33 | 2.99 |
As can be seen from the data in Table 1, under the condition of the same net slurry ratio and similar out-of-machine fluidity, the example 1-7 (the novel polycarboxylate water reducer special for machine-made sand in the invention) has smaller plastic viscosity and larger yield stress than the comparative example 1-5, which shows that the net slurry of the example using two monomers with different sizes in the dosage range to jointly introduce the catechol functional group has better adhesion effect and better fluidity. The comparative examples 1-2 are conventional polycarboxylate superplasticizers, and have no catechol anchoring groups, so that the adhesion effect is poor. Comparative example 3 the polycarboxylate superplasticizer has reduced dispersing and water reducing effects due to too high content of dopamine monomer, so that the same fluidity can be achieved, the slurry viscosity is higher, and the adhesion is not ideal enough. Comparative examples 4 to 5 are polycarboxylic acid water reducers in which a catechol functional group was introduced by using one monomer alone, and the performance was also relatively poor when two monomers were used simultaneously. This suggests a synergistic effect of the two modifying monomers therein, which may be due to the hierarchical and buffering effects of the long and short branches when co-anchored at the surface.
The novel polycarboxylate superplasticizer special for machine-made sand and a comparative polycarboxylate superplasticizer are used for carrying out mortar test according to GB/T17671 cement mortar Strength test method, cement is used as reference cement, sand is basalt machine-made sand, the fluidity of the mortar is adjusted to 190 +/-10 mm, and then the mortar is subjected to consistency and layering test and forming compressive strength test for 7 d. The test results are shown in Table 2.
TABLE 2 mortar test results
| Sample (I) | Fluidity of mortar | Consistency of | Degree of delamination | 7d compressive strength |
| Example 1 | 193 | 92 | 10 | 44.3 |
| Example 2 | 188 | 95 | 9 | 46.4 |
| Example 3 | 186 | 97 | 11 | 42.6 |
| Example 4 | 195 | 93 | 8 | 47.7 |
| Example 5 | 189 | 100 | 9 | 43.9 |
| Example 6 | 190 | 94 | 11 | 46.9 |
| Example 7 | 187 | 96 | 12 | 43.2 |
| Comparative example 1 | 186 | 88 | 30 | 34.9 |
| Comparative example 2 | 190 | 85 | 29 | 34.2 |
| Comparative example 3 | 193 | 90 | 23 | 37.5 |
| Comparative example 4 | 188 | 88 | 25 | 36.7 |
| Comparative example 5 | 191 | 87 | 26 | 35.5 |
The data in the table show that the consistency, the layering degree and the 7d compressive strength of the examples 1 to 7 are better than those of the comparative examples 1 to 5, which shows that the viscosity of the mortar can be effectively reduced, the adhesive capacity of the mortar is improved, and the segregation of the mortar is reduced.
The novel polycarboxylate superplasticizer special for machine-made sand and a comparative polycarboxylate superplasticizer are respectively used in machine-made sand C30 concrete for tests, and the sand is iron tailing sand. The concrete test is carried out according to GB/T50080-2002 Standard of Performance test method of common concrete mixture and GB/T50081-2019 Standard of Performance test method of physical and mechanical Properties of concrete, the slump of the concrete is adjusted to 220 +/-10 mm, the state of the mixture is recorded, and the pressure bleeding rate ratio and the 28d compressive strength after forming are tested. The mixing proportion of the C30 concrete is shown in Table 3. The concrete test results are shown in Table 4.
TABLE 3C 30 concrete mixing ratio
| Cement | Fly ash | Machine-made sand | Crushing stone | Water (W) |
| 300 | 80 | 820 | 1086 | 165 |
TABLE 4 concrete test results
| Sample (I) | Slump/spread (mm) | Pressure bleeding ratio (%) | 28d compressive Strength (MPa) | State of mixture |
| Example 1 | 225/585 | 12 | 41.7 | No bleeding, segregation and stone exposure and bottom grabbing phenomena, and good fluidity, cohesiveness and workability. |
| Example 2 | 230/590 | 11 | 42.7 | No bleeding, segregation and stone exposure and bottom grabbing phenomena, and good fluidity, cohesiveness and workability. |
| Example 3 | 220/580 | 13 | 41.4 | No bleeding, segregation and stone exposure and bottom grabbing phenomena, and good fluidity, cohesiveness and workability |
| Example 4 | 215/570 | 10 | 40.7 | No bleeding, segregation and stone exposure and bottom grabbing phenomena, and good fluidity, cohesiveness and workability |
| Example 5 | 225/585 | 12 | 41.3 | No bleeding, segregation and stone exposure and bottom grabbing phenomena, and good fluidity, cohesiveness and workability |
| Example 6 | 230/600 | 13 | 42.8 | No bleeding, segregation and stone exposure and bottom grabbing phenomena, and good fluidity, cohesiveness and workability |
| Example 7 | 225/575 | 12 | 40.8 | No bleeding, segregation and stone exposure and bottom grabbing phenomena, and good fluidity, cohesiveness and workability |
| Comparative example 1 | 220/585 | 33 | 35.1 | The serious bleeding and the slurry bleeding have obvious stone exposure phenomenon and poor workability and cohesiveness. |
| Comparative example 2 | 215/590 | 37 | 35.3 | Serious bleeding and slurry bleeding, obvious stone exposure, poor workability and cohesiveness |
| Comparative example 3 | 220/585 | 29 | 34.1 | Certain bleeding occurs, certain stone exposure occurs, and workability and cohesiveness are general |
| Comparative example 4 | 230/610 | 33 | 36.3 | The serious bleeding and the slurry bleeding have obvious stone exposure phenomenon and poor workability and cohesiveness. |
| Comparative example 5 | 225/600 | 35 | 35.8 | The serious bleeding and the slurry bleeding have obvious stone exposure phenomenon and poor workability and cohesiveness. |
As can be seen from the data in Table 4, when the concrete mixture prepared in the embodiments 1 to 7 is used in machine-made sand concrete, the concrete mixture is better than the concrete mixture prepared in the comparative examples 1 to 5 in state, and the pressure bleeding rate ratio and the 28d compressive strength are obviously better. The invention can effectively improve the adhesive capacity of slurry, thereby improving the workability of the mixture and preventing bleeding and bleeding, thereby improving the homogeneity of the whole concrete mixture and playing a role in improving the concrete strength along with the coordination function and the hydrogen bond function of the catechol functional group.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any way, and any simple modification, equivalent change and modification made to the above embodiment according to the technical spirit of the present invention are within the scope of the present invention without departing from the technical spirit of the present invention.
Claims (9)
1. A novel polycarboxylate superplasticizer special for machine-made sand is characterized in that a high polymer solution is obtained by polymerizing a polyether macromonomer, a dopa modified polyether macromonomer, unsaturated carboxylic acid, unsaturated carboxylic ester and a dopamine monomer in the presence of an initiator and a chain transfer agent.
2. The novel polycarboxylate superplasticizer special for machine-made sand according to claim 1, characterized in that the molar ratio of said polyether macromonomer, dopa-modified polyether macromonomer, unsaturated carboxylic acid ester, dopamine monomer is 1: (0.2-0.8): (1.5-6): (0.5-2): (0.2-0.8).
3. The novel polycarboxylate superplasticizer according to claim 1, wherein the polyether macromonomer is at least one of isobutylene polyglycol ether (HPEG), prenol polyglycol ether (TPEG), Allyl Polyglycol Ether (APEG) and ethylene glycol monovinyl Ether Polyoxyethylene Ether (EPEG) with molecular weight of 1800-3000, the unsaturated carboxylic acid is at least one of acrylic acid, methacrylic acid, fumaric acid and itaconic acid, and the unsaturated carboxylic acid ester is at least one of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxybutyl acrylate and hydroxypropyl methacrylate.
4. The novel polycarboxylate superplasticizer special for machine-made sand according to claim 1, characterized in that the molecular weight of said dopa-modified polyether macromonomer is 1600-2400, and the structure is as follows:
wherein p = 1-3; when n =1, the modified poly (isobutylene) glycol ether is dopa, and when n =2, the modified poly (isopentenol) glycol ether is dopa.
5. The novel polycarboxylate water reducer special for machine-made sand according to claim 1, characterized in that the dopamine monomer is at least one of dopamine methacrylamide, dopamine acrylamide, dopamine methacrylamide and dopamine acrylamide.
6. The method of claim 1, wherein the initiator is at least one of potassium persulfate, ammonium persulfate, azodiisopropylamidine oxazoline hydrochloride, azodiisobutyamidine dihydrochloride, a hydrogen peroxide-ascorbic acid initiation system, a hydrogen peroxide-rongalite initiation system, and an ammonium persulfate-sodium sulfite initiation system, the amount of the initiator is 0.3-3% of the amount of the monomer, and the chain transfer agent is at least one of mercaptoethanol, mercaptoacetic acid, mercaptopropionic acid, mercaptopropanol, sodium hypophosphite, trisodium phosphate, and CTA1420, and the amount of the chain transfer agent is 0.2-2% of the amount of the monomer.
7. The preparation method of the special novel polycarboxylate superplasticizer for machine-made sand according to claims 1-6, characterized by comprising the following steps: adding a polyether macromonomer, a dopa modified polyether macromonomer and water into a reaction container to be dissolved uniformly, respectively dropwise adding a polymerization monomer solution (containing unsaturated carboxylic acid, unsaturated carboxylic ester and dopamine monomer) and an initiator solution (containing initiator and chain transfer agent) into a reaction bottle under the stirring condition, keeping the temperature and continuously reacting to obtain a polymerization product solution after dropwise adding is finished, and adding a proper amount of alkali into the polymerization product solution to adjust the pH value to obtain the novel polycarboxylate superplasticizer special for machine-made sand.
8. The preparation method according to claim 7, wherein the polymerization temperature is 18 to 70 ℃, the dropping time of the polymerization monomer solution and the initiator solution is 1.5 to 3 hours and 2 to 3.5 hours, respectively, the dropping time of the polymerization monomer solution is less than that of the initiator solution, the holding time is 1 to 3.5 hours, and the alkali is at least one of sodium hydroxide, potassium hydroxide, triethylamine and triethanolamine or an aqueous solution thereof.
9. The use of the novel polycarboxylate superplasticizer special for machine-made sand according to claim 1 as a water reducer or a concrete conditioner for machine-made sand.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113603827A (en) * | 2021-07-26 | 2021-11-05 | 湖北工业大学 | Machine-made sand regulator of alcohol ether modified carboxylic acid polymer and preparation method thereof |
| CN114133467A (en) * | 2021-12-16 | 2022-03-04 | 科之杰新材料集团浙江有限公司 | Unsaturated esterified monomer and ester low-bleeding polycarboxylate superplasticizer and preparation method thereof |
| CN114213586A (en) * | 2021-12-16 | 2022-03-22 | 科之杰新材料集团浙江有限公司 | Solid high-water-retention polycarboxylate superplasticizer and preparation method thereof |
| CN118005311A (en) * | 2024-02-19 | 2024-05-10 | 佛山市利宇达建材有限公司 | Machine-made sand regulator and preparation method thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20130324674A1 (en) * | 2012-05-11 | 2013-12-05 | Navid Saleh | Polymeric Additive for Strength, Deformability, and Toughness Enhancement of Cemetitious Materials and Composites |
| CN106431064A (en) * | 2016-10-13 | 2017-02-22 | 赖高生 | Slow-release polycarboxylate water reducer as well as preparation method and application thereof |
| CN108865018A (en) * | 2018-07-06 | 2018-11-23 | 福建农林大学 | A kind of water solubility DOPA adhesive and preparation method thereof |
| CN109880023A (en) * | 2019-03-18 | 2019-06-14 | 云南富龙高速公路建设指挥部 | A kind of morning strong crack resistance type Machine-made Sand polycarboxylate water-reducer and preparation method thereof |
| CN110734754A (en) * | 2019-09-18 | 2020-01-31 | 中海石油(中国)有限公司湛江分公司 | Plugging agent composition, plugging agent, preparation method and application thereof |
-
2021
- 2021-01-15 CN CN202110057254.7A patent/CN112661914B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20130324674A1 (en) * | 2012-05-11 | 2013-12-05 | Navid Saleh | Polymeric Additive for Strength, Deformability, and Toughness Enhancement of Cemetitious Materials and Composites |
| CN106431064A (en) * | 2016-10-13 | 2017-02-22 | 赖高生 | Slow-release polycarboxylate water reducer as well as preparation method and application thereof |
| CN108865018A (en) * | 2018-07-06 | 2018-11-23 | 福建农林大学 | A kind of water solubility DOPA adhesive and preparation method thereof |
| CN109880023A (en) * | 2019-03-18 | 2019-06-14 | 云南富龙高速公路建设指挥部 | A kind of morning strong crack resistance type Machine-made Sand polycarboxylate water-reducer and preparation method thereof |
| CN110734754A (en) * | 2019-09-18 | 2020-01-31 | 中海石油(中国)有限公司湛江分公司 | Plugging agent composition, plugging agent, preparation method and application thereof |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113603827A (en) * | 2021-07-26 | 2021-11-05 | 湖北工业大学 | Machine-made sand regulator of alcohol ether modified carboxylic acid polymer and preparation method thereof |
| CN113603827B (en) * | 2021-07-26 | 2022-08-05 | 湖北工业大学 | Machine-made sand regulator of alcohol ether modified carboxylic acid polymer and preparation method thereof |
| CN114133467A (en) * | 2021-12-16 | 2022-03-04 | 科之杰新材料集团浙江有限公司 | Unsaturated esterified monomer and ester low-bleeding polycarboxylate superplasticizer and preparation method thereof |
| CN114213586A (en) * | 2021-12-16 | 2022-03-22 | 科之杰新材料集团浙江有限公司 | Solid high-water-retention polycarboxylate superplasticizer and preparation method thereof |
| CN114213586B (en) * | 2021-12-16 | 2023-08-25 | 科之杰新材料集团浙江有限公司 | Solid high-water-retention polycarboxylate superplasticizer and preparation method thereof |
| CN118005311A (en) * | 2024-02-19 | 2024-05-10 | 佛山市利宇达建材有限公司 | Machine-made sand regulator and preparation method thereof |
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