CN103896506B - A kind of lower molecular weight water reducer and its preparation method and application - Google Patents
A kind of lower molecular weight water reducer and its preparation method and application Download PDFInfo
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- CN103896506B CN103896506B CN201210574334.0A CN201210574334A CN103896506B CN 103896506 B CN103896506 B CN 103896506B CN 201210574334 A CN201210574334 A CN 201210574334A CN 103896506 B CN103896506 B CN 103896506B
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Abstract
Open one has the lower molecular weight water reducer of structure shown in formula (I), and in formula, n is the positive integer of 10 ~ 100; And A is ethylidene, propylidene, isopropylidene, butylidene or isobutylidene independently of one another.Also disclose the method for this lower molecular weight water reducer of preparation, comprise the steps: that the citric acid measured or its salt and catalyzer are added in autoclave by (1), and nitrogen replacement is carried out three times to reactor; (2) start stirring, and reactor is heated up, add a little epoxy alkane simultaneously; (3) raise until temperature and after pressure drop, add the epoxy alkane of metered amount, simultaneously when maintaining temperature of reaction, order reaction continues 30 ~ 50 minutes, to pressure no longer declines; And reaction product is lowered the temperature and neutralizes by (4), obtain described lower molecular weight water reducer.This lower molecular weight water reducer can use with conventional polycarboxylic acids water reducing agent compositional, makes concrete keep mobility for a long time, and ensures the concrete workability that silt content is higher.
Description
Technical field
The present invention relates to a kind of concrete admixture and its preparation method and application, more specifically, the present invention relates to a kind of lower molecular weight water reducer and its preparation method and application.
Background technology
Current the reinforcement of concrete water reducer mainly contains naphthalene water reducer and polycarboxylate water-reducer two kinds, and naphthalene water reducer is comparatively strong containing cement concrete adaptability to height, but its dispersion and function of slump protection poor.Polycarboxylate water-reducer has excellent dispersion and function of slump protection, but constrains its application in commerical ready-mixed concrete to the too high concrete of silt content is too responsive.For head it off, in industry, professional person proposes the theory of lower molecular weight water reducer: the small carboxylic acid molecules's water reducer preparing a kind of single tail, composite conventional type polycarboxylate water-reducer, lower molecular weight water reducer linear structure can be inserted in the laminated structure of mud particles, thus hinder the absorption consumption of earth to polycarboxylate water-reducer of strong adsorptive power, make the active adsorption amount of polycarboxylate water-reducer maintenance to cement granules, ensure the workability of fresh concrete and the intensity of maturing.
Foreword is compared in the research of lower molecular weight water reducer, and the pertinent literature related to is less.Patent US6309457B1 has prepared a kind of bis phosphoric acid type lower molecular weight water reducer, and its structure is as (II):
Wherein 50≤n≤100 and be positive integer.
This lower molecular weight water reducer is applied to self-leveling concrete extraordinary performance, but patent its anti-mud characteristic not mentioned.
2006, in the meeting periodical of the 8th the concrete admixture international conference held in Italy, the article of a section " three class water reducers are on impact of tricalcium aluminate hydrate under gypsum exists " by name is also referred to above-mentioned a kind of bis phosphoric acid type lower molecular weight water reducer, and it is classified as the 3rd class except polycarboxylate water-reducer and naphthalene water reducer commonly uses cement water reducing agent.
Visible, lower molecular weight water reducer generally uses abroad, but its anti-mud effect is not by further systematic study.
Summary of the invention
In view of the foregoing, the present inventor attempts developing a kind of new lower molecular weight water reducer, and completes the present invention on this basis.
Therefore, on the one hand, the invention provides the lower molecular weight water reducer that one has structure shown in formula (I):
In formula
N is the positive integer of 10 ~ 100; And
A is ethylidene, propylidene, isopropylidene, butylidene or isobutylidene independently of one another.
In an embodiment of lower molecular weight water reducer according to the present invention, described A is ethylidene.
In another embodiment of lower molecular weight water reducer according to the present invention, described A is propylidene.
On the other hand, the invention provides the method that one prepares the lower molecular weight water reducer with structure shown in formula (I), the method comprises the steps:
(1) citric acid measured or its salt and catalyzer are added in autoclave, and nitrogen replacement is carried out three times to reactor;
(2) start stirring, and reactor is heated up, add a little epoxy alkane simultaneously;
(3) raise until temperature and after pressure drop, add the epoxy alkane of metered amount, simultaneously when maintaining temperature of reaction, order reaction continues 30 ~ 50 minutes, to pressure no longer declines; And
(4) reaction product lowered the temperature and neutralize, obtaining described lower molecular weight water reducer.
In an embodiment of method according to the present invention, described epoxy alkane be selected from oxyethane, epoxy n-propane, epoxy isopropyl alkane, epoxy normal butane or epoxy Trimethylmethane one or more.
In another embodiment of method according to the present invention, the mol ratio of described citric acid or its salt and described epoxy alkane is 0.01 ~ 0.1.
In another embodiment of method according to the present invention, described catalyzer be selected from potassium oxide, calcium oxide, sodium hydroxide, potassium hydroxide, potassium hydride KH, sodium hydride, potassium methylate, sodium methylate, polynite, montmorillonite, synthesis Mg-Al composite salt, mesopore molecular sieve, double metal cyanide or multi-metal cyanide complex one or more.
In another embodiment of method according to the present invention, the consumption of described catalyzer is 1 ~ 5% of described citric acid or its salt and described epoxy alkane total mass.
In another embodiment of method according to the present invention, described epoxy alkane is oxyethane and/or propylene oxide.
In another embodiment of method according to the present invention, described temperature of reaction is 90 ~ 130 DEG C, and described reaction pressure is 0.2 ~ 0.6MPa.
Again on the one hand, the present invention also provides the purposes of described lower molecular weight water reducer, its composite for conventional polycarboxylate water-reducer.
In composite usage, the consumption of described lower molecular weight water reducer be composite after water reducer quality 1 ~ 30%.
This lower molecular weight water reducer uses with conventional polycarboxylic acids water reducing agent compositional, when in this lower molecular weight water reducer and polycarboxylic acids water reducing agent compositional to concrete, because the ability of its absorption cement granules is weaker than polycarboxylate water-reducer, after the polycarboxylate water-reducer being adsorbed on cement particle surface is wrapped up by hydrate gradually, on cement granules after lower molecular weight water reducer continues and is adsorbed onto aquation, make concrete can keep mobility for a long time.In addition, because lower molecular weight water reducer has " linear structure ", be easy to be inserted in the laminated structure of mud granule in concrete, thus reduce the adsorptivity consumption of mud to polycarboxylate water-reducer, therefore effectively can ensure the concrete workability that silt content is higher.
Embodiment
By specific examples below, those skilled in the art more easily can understand above-mentioned and other advantage of the present invention.
In the following embodiments, the weight-average molecular weight of polyether product uses gel chromatograph to measure, and condition determination is as follows:
Chromatographic column: Shodex oHpak SB-G
Moving phase: water
Flow velocity: 0.5ml/ minute
Detector: Shodex RI101
Column temperature: room temperature, sample introduction concentration: 10mg/ml
In addition, used in the following embodiments raw material and specification thereof and source as shown in table 1.
Table 1 experimental raw specification and source
| Experimental raw | Specification | Source |
| Citric acid | Technical grade | Yangzhou Wei De Chemical Co., Ltd. |
| Oxyethane | Technical grade | Liaoyang petrochemical industry |
| Potassium hydroxide | Analytical pure | Tianjin recovery development in science and technology company limited |
Embodiment 1
By the potassium hydroxide of 48g citric acid and 0.23g, join in autoclave, after carrying out nitrogen replacement three times, reactor is heated up and starts stirring.When temperature in the kettle reaches kick off temperature, add 10g oxyethane, after temperature rising, pressure drop, the continual and steady oxyethane adding 228g, controls temperature of reaction 120 ~ 140 DEG C, controls flow and adds for 2 hours.After reinforced under constant temperature, carry out aging reaction 30 ~ 50 minutes, no longer decline to pressure, react complete, cooling, add acetic acid when reactor temperature is down to 90 DEG C and carry out neutralization reaction, be neutralized to polyether product pH dischargings after 5.0 ~ 7.0, namely obtain finished product, sampling detects, and weight-average molecular weight is 1000.
Embodiment 2
By the potassium hydroxide of 48g citric acid and 0.34g, join in autoclave, after carrying out nitrogen replacement three times, reactor is heated up and starts stirring.When temperature in the kettle reaches kick off temperature, add 10g oxyethane, after temperature rising, pressure drop, the continual and steady oxyethane adding 378g, controls temperature of reaction 120 ~ 140 DEG C, controls flow and adds for 2.5 hours.After reinforced under constant temperature, carry out aging reaction 30 ~ 50 minutes, no longer decline to pressure, react complete, cooling, add acetic acid when reactor temperature is down to 90 DEG C and carry out neutralization reaction, be neutralized to polyether product pH dischargings after 5.0 ~ 7.0, namely obtain finished product, sampling detects, and weight-average molecular weight is 1600.
Embodiment 3
By the potassium hydroxide of 48g citric acid and 0.47g, join in autoclave, after carrying out nitrogen replacement three times, reactor is heated up and starts stirring.When temperature in the kettle reaches kick off temperature, add 10g oxyethane, after temperature rising, pressure drop, the continual and steady oxyethane adding 528g, controls temperature of reaction 120 ~ 140 DEG C, controls flow and adds for 3 hours.After reinforced under constant temperature, carry out aging reaction 30 ~ 50 minutes, no longer decline to pressure, react complete, cooling, add acetic acid when reactor temperature is down to 90 DEG C and carry out neutralization reaction, be neutralized to polyether product pH dischargings after 5.0 ~ 7.0, namely obtain finished product, sampling detects, and weight-average molecular weight is 2200.
Embodiment 4
By the potassium hydroxide of 48g citric acid and 0.60g, join in autoclave, after carrying out nitrogen replacement three times, reactor is heated up and starts stirring.When temperature in the kettle reaches kick off temperature, add 10g oxyethane, after temperature rising, pressure drop, the continual and steady oxyethane adding 678g, controls temperature of reaction 120 ~ 140 DEG C, controls flow and adds for 3 hours.After reinforced under constant temperature, carry out aging reaction 30 ~ 50 minutes, no longer decline to pressure, react complete, cooling, add acetic acid when reactor temperature is down to 90 DEG C and carry out neutralization reaction, be neutralized to polyether product pH dischargings after 5.0 ~ 7.0, namely obtain finished product, sampling detects, and weight-average molecular weight is 2800.
Lower molecular weight water reducer performance evaluation
In order to understand characteristic of the present invention and advantage better, lower molecular weight water reducer of the present invention is also applied in actual concrete by contriver.
First, the sample of needs and cement, sand, stone, water are carried out blending with certain proportioning by JGJ55.Experiment material and specification are in table 2, and concrete mix is in table 3.
Table 2 experiment material and specification
| Experiment material | Specification |
| Sand | Medium sand (river sand) |
| Stone | Particle diameter 16 ~ 31.5mm |
| Reference cement | Special PI 42.5 checked by concrete admixture |
Table 3 concrete mix
" water cement ratio " in table refers to the mass ratio of cement and water in concrete; " sand coarse aggregate ratio " refers to the mass ratio of sand and sand and stone summation in concrete; " water reducer volume " adds the consumption of cement quality 0.2% after referring to that polycarboxylate water-reducer folding is solid.After " slump " refers to that fresh concrete flows out from slump bucket, the top of slump bucket and the distance of concrete vertex.Various concrete test material and envrionment temperature all should remain on (20 ± 3) DEG C.Adopt that to meet the nominal capacity that JG3036 requires be the single horizontal shaft type forced stirrer of 60 liters, cement, sand, stone are once dropped into stirrer, then adds the mixing water being mixed with admixture and stir 2 minutes, after discharging together, with manually turning to evenly on iron plate, test.A sample got by each concrete, initial slump and after 1 hour the slump all represent with the mean value of three test-results.Concrete slump measures according to GB/T50080, and slump bucket divides two-layer charging, and every layer of loading is highly the half that cylinder is high, and every layer plugging and pounding 15 times with plugging and pounding rod, vertically being mentioned by cylinder, makes concrete be natural flow state, measures the slump.The slump represents by the mean value of the result that three tests record.After measuring in the test specimen tube that nuzzles up of loading gauze, container is added a cover, and leaving standstill to 1 hour (calculating when stirring from adding water), then pouring out, and iron plate turns to after evenly with spade, again measures the slump.
Lower molecular weight water reducer prepared by embodiment 1 to 4 is designated as min-sp1, min-sp2, min-sp3 and min-sp4, select a kind of commercially available conventional polycarboxylate water-reducer and be designated as con-sp, conventional polycarboxylate water-reducer is generally unsaturated organic acid (methyl) vinylformic acid and unsaturated end alkenyl polyether by the free-radical polymerized and high molecular polymer with comb-type structure shown in formula III that is that obtain:
Wherein R
1, R
2and R
3represent hydrogen atom or methyl, three can be identical or different;
The alkylidene group of X representative containing 2 ~ 4 carbon atoms;
X, y, z, m and n be greater than zero positive integer;
X, y, z general scope is 1 ~ 6;
M general scope is 10 ~ 30; And
N general scope is 10 ~ 60.
When conventional polycarboxylate water-reducer is used alone and uses with the lower molecular weight water reducer of the present invention is composite, concrete performance is as shown in table 4 below.
Table 4 lower molecular weight water reducer performance evaluation
Note: test sample description of symbols, if the test sample being designated as con-sp/min-sp1 (80/20) is the composite sample of 80% (massfraction) con-sp polycarboxylate water-reducer and the mixing of 20% lower molecular weight water reducer.
As can be seen from Table 4: (1) is used alone conventional polycarboxylate water-reducer con-sp, concrete 1 hour slump-loss is comparatively large, initial slump 220mm, and after 1 hour, the slump is only 80mm, performance of having lost the job; (2), after the harmonic component water reducer that the present invention of conventional water reducer composite 20% synthesizes, initial slump slightly reduces, and after 1 hour, the slump obviously promotes, particularly the polycarboxylate water-reducer compound sample of composite 20%min-sp4, and slump retention ability is obvious; (3) along with the minimizing of the composite amount of harmonic component water reducer, the slump also corresponding minimizing in concrete 1 hour, illustrates that the lifting of institute's test specimens slump performance is that lower molecular weight water reducer brought; And the lower molecular weight water reducer prepared of (4) the present invention and conventional polycarboxylic acids water reducing agent compositional can both keep the serviceability of fresh concrete the long period.
Claims (12)
1. there is a lower molecular weight water reducer for structure shown in formula (I),
In formula
N is the positive integer of 10 ~ 100; And
A is ethylidene, propylidene, isopropylidene, butylidene or isobutylidene independently of one another.
2. lower molecular weight water reducer according to claim 1, wherein said A is ethylidene.
3. lower molecular weight water reducer according to claim 1, wherein said A is propylidene.
4. prepare a method for the lower molecular weight water reducer any one of claims 1 to 3, comprise the steps:
(1) citric acid measured or its salt and catalyzer are added in autoclave, and nitrogen replacement is carried out three times to reactor;
(2) start stirring, and reactor is heated up, add a little epoxy alkane simultaneously;
(3) raise until temperature and after pressure drop, add the epoxy alkane of metered amount, simultaneously when maintaining temperature of reaction, order reaction continues 30 ~ 50 minutes, to pressure no longer declines; And
(4) reaction product lowered the temperature and neutralize, obtaining described lower molecular weight water reducer.
5. method according to claim 4, wherein said epoxy alkane be selected from oxyethane, epoxy n-propane, epoxy isopropyl alkane, epoxy normal butane or epoxy Trimethylmethane one or more.
6. method according to claim 4, the mol ratio of wherein said citric acid or its salt and described epoxy alkane is 0.01 ~ 0.1.
7. the method any one of claim 4 ~ 6, wherein said catalyzer be selected from potassium oxide, calcium oxide, sodium hydroxide, potassium hydroxide, potassium hydride KH, sodium hydride, potassium methylate, sodium methylate, polynite, montmorillonite, synthesis Mg-Al composite salt, mesopore molecular sieve, double metal cyanide or multi-metal cyanide complex one or more.
8. method according to claim 7, the consumption of wherein said catalyzer is 1 ~ 5% of described citric acid or its salt and described epoxy alkane total mass.
9. method according to claim 7, wherein said epoxy alkane is oxyethane and/or propylene oxide.
10. method according to claim 7, wherein said temperature of reaction is 90 ~ 130 DEG C.
11. any one of claims 1 to 3 or the purposes of lower molecular weight water reducer prepared by method any one of claim 4 ~ 10, its composite for conventional polycarboxylate water-reducer.
12. purposes according to claim 11, consumption when wherein this lower molecular weight water reducer is composite be composite after water reducer quality 1 ~ 30%.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101108896A (en) * | 2006-07-20 | 2008-01-23 | 拜尔材料科学有限公司 | High water content tolerant process for the production of polyethers |
| CN101928391A (en) * | 2009-06-23 | 2010-12-29 | 拜尔材料科学有限公司 | By the short chain polyether polyols of ultra-low water-content starters by the DMC catalytic preparation |
| CN101952347A (en) * | 2008-02-15 | 2011-01-19 | 巴斯夫欧洲公司 | Highly functional polyetherols and the production and use thereof |
| CN102504238A (en) * | 2011-10-10 | 2012-06-20 | 江苏博特新材料有限公司 | Unsaturated polyether monomer, comb-like branched copolymer cement dispersant prepared by the same, and preparation method thereof |
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| KR100950719B1 (en) * | 2005-09-27 | 2010-03-31 | 니폰 쇼쿠바이 컴파니 리미티드 | Novel polymer and cement admixture using the same |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101108896A (en) * | 2006-07-20 | 2008-01-23 | 拜尔材料科学有限公司 | High water content tolerant process for the production of polyethers |
| CN101952347A (en) * | 2008-02-15 | 2011-01-19 | 巴斯夫欧洲公司 | Highly functional polyetherols and the production and use thereof |
| CN101928391A (en) * | 2009-06-23 | 2010-12-29 | 拜尔材料科学有限公司 | By the short chain polyether polyols of ultra-low water-content starters by the DMC catalytic preparation |
| CN102504238A (en) * | 2011-10-10 | 2012-06-20 | 江苏博特新材料有限公司 | Unsaturated polyether monomer, comb-like branched copolymer cement dispersant prepared by the same, and preparation method thereof |
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