Modified naphthalene series water reducing agent for concrete with high slit content, and preparation method and application thereof

Abstract

A modified naphthalene series water reducing agent for concrete with high slit content, and preparation method and application thereof, belonging to the field of concrete admixtures, and comprising the following components by weight: 20-30 wt % of naphthalene series water reducing agent, 10-20 wt % of high molecular weight polyethylene, 0.1-1 wt % of solid acid catalyst, and the balance of alkane solvent, and the sum of the components is 100 wt %. The present invention provides a simple preparation method for the water reducing agent, and the prepared solvent can be recycled, moreover, on the premises of not increasing costs, the prepared water reducing agent can not only effectively solve the fluidity decline of fresh concrete prepared by aggregate with high slit content, but improves the mechanical strength and other properties of concrete, in order to meet the construction requirements of concrete works.

Claims

1. A modified naphthalene series water reducing agent for concrete with high slit content, comprising the following components by weight: 20-30 wt % of naphthalene series water reducing agent, 10-20 wt % of high molecular weight polyethylene, 0.1-1 wt % of solid acid catalyst, and the balance of alkane solvent, and the sum of the components is 100 wt %; wherein the naphthalene series water reducing agent is an intermediate prepared through sulfonation, hydrolysis and condensation, and its main component is industrial naphthalene, and the relative molecular weight of naphthalene series water reducing agent is 2000 g/mol-3000 g/mol; wherein the preparation method of modified naphthalene series water reducing agent for concrete with high slit content comprising the following steps: mixing alkane solvent, naphthalene water reducing agent, high molecular weight polyethylene and solid acid catalyst for esterification, in order to obtain esters; mixing esters with a water carrying agent for reaction, in order to obtain the modified naphthalene-based water reducing agent for high-silt-content concrete; and wherein the temperature of esterification is 120° C.-160° C. and the reaction time is 3˜4 h.

2. The modified naphthalene series water reducing agent for concrete with high slit content, according to claim 1, wherein, the structural formula of naphthalene series water reducing agent is illustrated as follows: ##STR00005## wherein, n is 10-14.

3. (canceled)

4. The modified naphthalene series water reducing agent for concrete with high slit content, according to claim 1, wherein, the structural formula of high molecular weight polyethylene is illustrated as follows: ##STR00006## wherein, R is a saturated or unsaturated alkyl (C12-C18), and n is 100-150.

5. The modified naphthalene series water reducing agent for concrete with high slit content, according to claim 1, wherein, the high molecular weight polyethylene is a nonionic surfactant with a relative molecular weight of more than 5000 g/mol.

6. The modified naphthalene series water reducing agent for concrete with high slit content, according to claim 1, wherein, the solid acid catalyst, including one or more of copper sulfate, zinc sulfate and manganese sulfate.

7. The modified naphthalene series water reducing agent for concrete with high slit content, according to claim 1, wherein, the alkane solvent, including one or more of heptane, octane, undecane or dodecane.

8. (canceled)

9. (canceled)

10. An application method of the modified naphthalene series water reducing agent for concrete with high slit content, according to claim 1 in fresh concrete prepared by aggregate with high slit content.

Description

DETAILED DESCRIPTION OF EMBODIMENTS

[0024] A modified naphthalene series water reducing agent for concrete with high slit content, comprising the following components by weight: 20-30 wt % of naphthalene series water reducing agent, 10-20 wt % of high molecular weight polyethylene, 0.1-1 wt % of solid acid catalyst, and the balance of alkane solvent, and the sum of the components is 100 wt %.

[0025] According to this invention, the naphthalene series water reducing agent is 20-30 wt %%, preferably 22-28 wt %, more preferably 25 wt %;

[0026] Preferably, the structural formula of naphthalene series water reducing agent is illustrated as follows:

##STR00003## [0027] wherein, n is 10-14.

[0028] Preferably, the naphthalene series water reducing agent is an intermediate prepared through sulfonation, hydrolysis and condensation, and its main component is industrial naphthalene, and the relative molecular weight of naphthalene series water reducing agent is 2000 g/mol-3000 g/mol.

[0029] According to the invention, the source of the naphthalene series water reducing agent is not particularly limited, and the naphthalene series water reducing agent can be synthesized by a conventional synthesis method or purchased from market directly. Furthermore, the modified naphthalene series water reducing agent for concrete with high slit content contains naphthalene sulfonate component, which can make cement particles have electrostatic adsorption, hence adsorbing a large amount of anionic charges to the surface of cement particles, and then the cement particles are uniformly dispersed by electrostatic repulsion among cement particles.

[0030] According to this invention, the high molecular weight polyoxyethylene is 10-20 wt %, preferably 12-18 wt %, more preferably 15 wt %.

[0031] the structural formula of high molecular weight polyethylene is illustrated as follows:

##STR00004## [0032] wherein, R is a saturated or unsaturated alkyl (C12-C18), and n is 100-150.

[0033] The high molecular weight polyoxyethylene is a nonionic surfactant, and its relative molecular weight is preferably greater than 5000 g/mol.

[0034] According to the invention, the source of the high molecular weight polyoxyethylene is not particularly limited, and it can be synthesized by a conventional synthesis method or purchased from market directly. Furthermore, the molecular structure of the modified naphthalene series water reducing agent has high molecular weight polyoxyethylene side chains introduced through esterification, and its spatial steric impedance size is much larger than the layer spacing of clay, which effectively hinders the adsorption of clay to the modified naphthalene series water reducing agent, therefore, this invention solves serious loss of fluidity of concrete prepared with high silt aggregate, moreover, according to this invention, naphthalene series water reducing agent and polyoxyethylene are bonded by chemical bonds, making the structure stable and not affected by system temperature and pH.

[0035] According to this invention, the solid acid catalyst is 0.1-1 wt %, preferably 0.3-0.8 wt %, more preferably 0.5 wt %; the solid acid catalyst preferably comprises one or more of copper sulfate, zinc sulfate and manganese sulfate. The source of the solid acid catalyst is not particularly limited, and commercial products well known in the art can be used.

[0036] According to this invention, under the action of solid acid catalyst, the sulfonic acid group on the molecular structure of nnaphthalene series water reducing agent and the terminal hydroxyl group on the molecular structure of polyoxyethylene are made for esterification, and subsequent modified naphthalene series water reducing agent contains naphthalene sulfonate components, which enable cement particles for electrostatic adsorption, hence adsorbing a large amount of anionic charges to the surface of cement particles, and then the cement particles are uniformly dispersed by electrostatic repulsion among cement particles.

[0037] According to this invention, the alkane solvent preferably includes one or more of heptane, octane, undecane or dodecane. According to the invention, the source of the alkane solvent is not particularly limited, and available products well known in the art can be used. Furthermore, the alkane solvent is the reaction solvent of esterification, and it is used for dissolving naphthalene water reducer, high molecular weight polyoxyethylene and solid acid catalyst.

[0038] This invention also provides a preparation method of modified naphthalene series water reducing agent for concrete with high slit content, comprising the following steps:

[0039] Step 1, mixing alkane solvent, naphthalene water reducing agent, high molecular weight polyethylene and solid acid catalyst for esterification, in order to obtain esters;

[0040] Step 2, mixing esters with a water carrying agent for reaction, in order to obtain the modified naphthalene-based water reducing agent for high-silt-content concrete.

[0041] According to the invention, alkane solvent, naphthalene series water reducing agent, high molecular weight polyoxyethylene and solid acid catalyst are mixed for esterification to obtain esterification reaction products.

[0042] According to the invention, it is preferable to add alkane solvent into a three-necked flask, and then add naphthalene series water reducing agent, high molecular weight polyoxyethylene and solid acid catalyst.

[0043] According to the invention, the temperature of the esterification is preferably 120° C.-160° C., more preferably 130° C.-150° C., most preferably 140° C., and the time of the esterification is preferably 3-4 h, more preferably 3.5 h.

[0044] According to the invention, It mixes the obtained esters with a water-carrying agent for reaction, thus obtaining the modified naphthalene series water reducing agent for concrete with high slit content.

[0045] Preferably, a water-carrying agent is preferably added into the esters, and the reaction continues for 1-2 h before completion.

[0046] According to this invention, the water-carrying agent is preferably isopropanol, the dosage of the water-carrying agent is preferably 1-2 wt %, and the mass ratio of the water-carrying agent to the high molecular weight polyoxyethylene is preferably 1:10. Furthermore, the source of isopropanol is not particularly limited, and commercially available products well known in the art can be used.

[0047] After the reaction is completed, the present invention preferably recovers alkane solvent through reduced pressure distillation, in order to obtain the modified naphthalene series water reducing agent for concrete with high slit content.

[0048] According to the invention, the pressure of the vacuum distillation is preferably not less than −0.09 MPa, the temperature is preferably 30° C.˜50° C., and the time is preferably 2-4 h.

[0049] The present invention further provides the modified naphthalene series water reducing agent for concrete with high slit content and the application of modified naphthalene series water reducing agent for concrete with high slit content prepared by the preparation method in preparing concrete with high silt content aggregate.

[0050] The following embodiments explain in detail the modified naphthalene series water reducing agent for concrete with high slit content, its preparation method and application, but they should not be understood as limiting the protection scope of the present invention.

Embodiment 1

[0051] A modified naphthalene series water reducing agent for concrete with high slit content, comprising the following components by weight:

[0052] 20 wt % of naphthalene series water reducing agent, 10 wt % of high molecular weight polyethylene, 0.1 wt % of solid acid catalyst (copper sulfate), and 69.9 wt % alkane solvent (heptane);

[0053] 69.9 wt % alkane solvent was added into a three-necked flask, next, 20 wt % naphthalene water reducer, 10 wt % high molecular weight polyethylene and 0.1 wt % solid acid catalyst were added, and the temperature was raised to 120° C.;

[0054] esterification was carried out at 120° C. for 3 h, then isopropanol water-carrying agent was added into the reaction, and the reaction was carried on for 1 h;

[0055] vacuum distillation was applied after the reaction is finished, the alkane solvent was recovered, and modified naphthalene series water reducing agent for concrete with high slit content was obtained.

Embodiment 2

[0056] A modified naphthalene series water reducing agent for concrete with high slit content, comprising the following components by weight:

[0057] 20 wt % naphthalene series water reducing agent, 10 wt % high molecular weight polyethylene, 0.1 wt % solid acid catalyst (zinc sulfate) and 69.9 wt % alkane solvent (octane);

[0058] 69.9 wt % alkane solvent was added into a three-necked flask, next, 20 wt % naphthalene series water reducing agent, 10 wt % high molecular weight polyoxyethylene and 0.1 wt % solid acid catalyst were added, and the temperature was raised to 140° C.;

[0059] esterification at 140° C. for 3.5 h, during which, isopropanol water-carrying agent was added, and the reaction was carried on for 1.5 h;

[0060] vacuum distillation was carried out after the reaction was finished, the alkane solvent was recovered, and the modified naphthalene series water reducing agent for concrete with high slit content was obtained.

Embodiment 3

[0061] A modified naphthalene series water reducing agent for concrete with high slit content, comprising the following components by weight:

[0062] 20 wt % naphthalene series water reducing agent, 10 wt % high molecular weight polyoxyethylene, 0.1 wt % solid acid catalyst (manganese sulfate) and 69.9 wt % alkane solvent (undecane);

[0063] 69.9 wt % alkane solvent was added into a three-necked flask, then 20 wt % naphthalene water reducer, 10 wt % high molecular weight polyoxyethylene and 0.1 wt % solid acid catalyst were added, and the temperature was raised to 160° C.;

[0064] Esterification was carried out at 160° C. for 4 h, during which, isopropanol water-carrying agent was added, and the reaction was carried on for 2 h;

[0065] vacuum distillation was carried out after the reaction is finished, the alkane solvent was recovered, and the modified naphthalene series water reducing agent for concrete with high slit content was obtained.

Embodiment 4

[0066] A modified naphthalene series water reducing agent for concrete with high slit content, comprising the following components by weight:

[0067] 25 wt % naphthalene series water reducing agent, 15 wt % high molecular weight polyoxyethylene, 0.5 wt % solid acid catalyst (zinc sulfate) and 59.5 wt % alkane solvent (dodecane), and the sum of all components was 100 wt %.

[0068] 59.5 wt % alkane solvent was added into a three-necked flask, then 25 wt %% naphthalene series water reducing agent, 15 wt % high molecular weight polyoxyethylene and 0.5 wt % solid acid catalyst were added, and the temperature was raised to 120° C.;

[0069] esterification was carried out at 120° C. for 4 h, during which, isopropanol water-carrying agent was added, and the reaction was carried on for 2 h;

[0070] vacuum distillation was carried out after the reaction is finished, the alkane solvent was recovered, and the modified naphthalene series water reducing agent for concrete with high slit content was obtained.

Embodiment 5

[0071] A modified naphthalene series water reducing agent for concrete with high slit content, comprising the following components by weight:

[0072] 30 wt % naphthalene series water reducing agent, 20 wt % high molecular weight polyoxyethylene, 1 wt % solid acid catalyst (manganese sulfate) and 49 wt % alkane solvent (heptane), and the sum of all components was 100 wt %.

[0073] 49 wt % alkane solvent was added into a three-necked flask, then 30 wt % naphthalene water reducer, 20 wt % high molecular weight polyoxyethylene and lwt % solid acid catalyst were added, and raising the temperature to 150° C.;

[0074] Esterification was carried out at 150° C. for 3 h, during which, isopropanol water-carrying agent was added, and reaction was carried on for 2 h;

[0075] vacuum distillation was carried out after the reaction is finished, the alkane solvent was recovered, and the modified naphthalene series water reducing agent for concrete with high slit content was obtained.

Embodiment 6

[0076] A modified naphthalene series water reducing agent for concrete with high slit content, comprising the following components by weight:

[0077] 30 wt % naphthalene series water reducing agent, 20 wt % high molecular weight polyoxyethylene, 0.5 wt % solid acid catalyst (manganese sulfate) and 49.5 wt % alkane solvent (octane), and the sum of all components was 100 wt %.

[0078] 49.5 wt % alkane solvent was added into a three-necked flask, then 30 wt % naphthalene series water reducing agent, 20 wt % high molecular weight polyoxyethylene and 0.5 wt % solid acid catalyst were added, and the temperature was raised to 130° C.;

[0079] esterification at 130° C. for 4 h, during which isopropanol water-carrying agent was added, and reaction was carried on for 2 h;

[0080] vacuum distillation was carried out after the reaction is finished, the alkane solvent was recovered, and the modified naphthalene series water reducing agent for concrete with high slit content was obtained

Embodiment 7

[0081] A modified naphthalene series water reducing agent for concrete with high slit content, comprising the following components by weight:

[0082] 25 wt % naphthalene series water reducing agent, 15 wt % high molecular weight polyoxyethylene, 0.2 wt % solid acid catalyst (copper sulfate) and 59.8 wt % saturated alkane solvent (octane), and the sum of all components was 100 wt %.

[0083] 59.8 wt % alkane solvent was added into a three-necked flask, then 25 wt % naphthalene series water reducing agent, 15 wt % high molecular weight polyoxyethylene and 0.2 wt % solid acid catalyst were added, and the temperature was raised to 140° C.;

[0084] esterification at 140° C. for 3.5 h, during which isopropanol water-carrying agent was added, and reaction was carried on for 2 h;

[0085] vacuum distillation was carried out after the reaction is finished, the alkane solvent was recovered, and the modified naphthalene series water reducing agent for concrete with high slit content was obtained

Embodiment 8

[0086] A modified naphthalene series water reducing agent for concrete with high slit content, comprising the following components by weight:

[0087] 25 wt % naphthalene series water reducing agent, 15 wt % high molecular weight polyoxyethylene, 1 wt % solid acid catalyst (copper sulfate) and 59 wt % alkane solvent (heptane), and the sum of all components was 100 wt %.

[0088] 51 wt % alkane solvent was added into a three-necked flask, then 25 wt % naphthalene series water reducing agent, 15 wt % high molecular weight polyoxyethylene and 1 wt % solid acid catalyst were added, and the temperature was raised to 160° C.;

[0089] esterification at 160° C. for 2 h, during which isopropanol water-carrying agent was added, and reaction was carried on for 2 h;

[0090] vacuum distillation was carried out after the reaction is finished, the alkane solvent was recovered, and the modified naphthalene series water reducing agent for concrete with high slit content was obtained

Comparative Embodiment 1

[0091] 100 wt % naphthalene series water reducing agent procured from the market.

Comparative Embodiment 2

[0092] 40% solid polycarboxylate water reducing agent procured from the market

[0093] Net fluidity of cement paste test:

[0094] the fluidity of cement paste refers to the national standard GB/T 8077-2012 “Test Method for Uniformity of Concrete Admixtures”.

[0095] According to the clay mixing method to replace the corresponding quality of cement, the mixing amount is 5%; cement is the benchmark cement; comparative embodiment 1 uses commercially available naphthalene series water reducing agent (FDN) with the admixture content of 0.75% (based on the weight of cement after consolidation), and comparative embodiment 2 uses commercially available polycarboxylate water reducing agent with the admixture content of 0.20% (based on the weight of cement after consolidation), and the water-cement ratio of cement paste is 0.29.

[0096] See Table 1 for the test results.

[0097] Test results of fluidity and concrete performance of cement paste that uses modified naphthalene series water reducing agent provided by this invention

TABLE-US-00001 TABLE 1 Compressive Fluidity of strength/MPa cement Concrete 7 d 28 d paste/mm slump Compressive Compressive Sample Initial 1 h loss strength/MPa strength/MPa Embodiment 1 282 274 205 24.8 25.5 Embodiment 2 290 276 210 25.6 26.8 Embodiment 3 286 269 205 24.2 24.6 Embodiment 4 285 272 208 24.9 25.7 Embodiment 5 294 280 225 25.8 26.7 Embodiment 6 294 278 223 26.5 38.2 Embodiment 7 293 280 223 26.9 38.4 Embodiment 8 289 278 210 23.8 25.9 Comparative 276 252 203 21.6 31.9 embodiment 1 Comparative 255 210 168 19.2 28.7 embodiment 2

[0098] As can be seen from Table 1, the products of Embodiment 1-8 prepared by the present invention all have excellent initial net fluidity of cement paste and 1 h elapsed net of cement paste; However, the initial fluidity of the cement paste of the commercial unmodified naphthalene series water reducing agent in Comparative Embodiment 1 became worse, and the 1 h elapsed loss was 8.7%, the compatibility between the commercial polycarboxylate water reducing agent and clay was obvious, the initial fluidity of the cement paste is only 255 mm, and the 1 h elapsed loss fluidity loss rate was as high as 17.6%. Compared with the comparative embodiment, the concrete slump loss and 7-day and 28-day compressive strength were also greatly improved.

[0099] The above are only the preferred embodiments of the present invention, and it should be pointed out that for those of ordinary skill in the technical field, without departing from the principle of the present invention, several improvements and embellishments can be made, and these improvements and embellishments should also be regarded as the protection scope of the present invention.