The preparation method of viscosity reduction type polycarboxylic acid super-plasticizer and application
Technical field
The present invention relates to a kind of preparation method and application of viscosity reduction type polycarboxylic acid super-plasticizer, belong to technical field of concrete additives.
Background technology
Along with the high stratification of modern building, greatly collapsing and lightweight development, to concrete construction and specification of quality more and more higher, high strength, high pumping and high-durability become the developing direction of modern concrete.Compared with normal concrete, high-strength concrete (C60 ~ C90) and super high strength concrete (C100 and more than) have significant superiority: effectively can alleviate dead load; Increase building usable floor area; Save material and the energy, reduce building cost; Promote concrete durability etc., there is good economic and social benefit.At present, the method improving concrete strength mainly contains the cement, increase single cement consumption, reduction water cement ratio etc. that adopt high strength grade.But these technical measures directly cause concrete viscosity to increase, and mobility declines, thus reduces pumpability of concrete, affects operating efficiency, applies and is restricted thereupon.How to reduce the concern that viscosity that is high and super high strength concrete causes many scholars.
It is in the super high strength concrete of 120MPa that patent documentation CN103613348A reports in preparation average intensity, adopts the superfine powders such as large dosage silicon ash, breeze and microballon, reduces super high strength concrete viscosity, achieve the super high-rise pumping of more than 300m.Patent documentation CN102775110A reports and is preparing in super high strength concrete, adopts zeolite powder and Sunmorl N 60S as viscosity reduction plasticity-retention agent, more auxiliary ultrafine slag powder, fine limestone powder and microballon, greatly reduces the viscosity of super high strength concrete.Patent documentation CN103145360A reports a kind of high viscosity modifier with super high strength concrete, it adopts silicon ash, flyash, super-fine limestone powder or quartz powder and Inorganic to form by a certain percentage, for having the effect of viscosity reduction in super high strength concrete.But the measure of these viscosity reductions is all the scheme adopting admixture ultrafine inorganic powder to carry out physics packing lubrication, volume, up to more than 10%, increases considerably Cost of Concrete, and ultrafine inorganic powder tap density is little, mass per volume is little, is inconvenient to transport and use.
Polycarboxylic acid super-plasticizer is as third generation high performance concrete water reducer, its raw material sources are extensive, molecular structure is various, can with sulfonic group, carboxylic acid group, phosphates etc. are as adsorption group, and have and enrich adjustable hydrophilic side chain and play sterically hindered effect, drastically increase the dispersion lubrication to cement, there is volume low, water-reducing rate is high, mobility and the flowing retentivity of concrete batching system are good, lower shrinkage, molecular structure designability is strong, the advantages such as production technique is simple, be widely used in construction work, promote concrete quality to high performance future development.
Because polycarboxylic acid super-plasticizer molecular structure has stronger designability, by adjusting its main chain and side-chain structure, achieving high performance and the functionalization of polycarboxylic acid super-plasticizer, in height with super high strength concrete viscosity reduction, also showing great potential.Patent documentation CN104262550A discloses a kind of preparation method of viscosity reduction type polycarboxylate water-reducer, first react with the acid anhydrides minor comonomer and binary primary amine that contain unsaturated double-bond, prepare unsaturated primary amine class minor comonomer, and then carry out quaternizedly obtaining the unsaturated minor comonomer of quaternary ammonium salt, be polymerized with unsaturated ester class minor comonomer, unsaturated acids minor comonomer and unsaturated polyester polymeric monomer again, prepare viscosity reduction type polycarboxylate water-reducer.The method preparation process is more, and process is loaded down with trivial details, and the unsaturated minor comonomer preparation time of quaternary ammonium salt long (5 ~ 72h), prepared polycarboxylate water-reducer viscosity reducing effect is limited.Patent documentation CN103865007A discloses a kind of preparation method of viscosity reduction type polycarboxylate water-reducer, and it adopts random polyoxyethylene unsaturated acid ester, unsaturated modification Soxylat A 25-7, unsaturated alkyl ester and (methyl) vinylformic acid carry out copolymerization and obtain.But this polycarboxylate water-reducer is in the concrete of 0.24 at water-cement ratio, its bucket of falling slump emptying time reaches more than 39s, and viscosity reducing effect is very limited, is difficult to meet height with super high strength concrete to low viscous workability requirement.
Summary of the invention
Goal of the invention
An object of the present invention is to provide a kind of preparation method of viscosity reduction type polycarboxylic acid super-plasticizer, the method operating process is simple, prepared polycarboxylic acid super-plasticizer is used for high and super high strength concrete, effectively can reduce concrete viscosity, improve concrete workability and velocity of flow, be conducive to pumping construction.
Another object of the present invention is to provide the application of described viscosity reduction type polycarboxylic acid super-plasticizer as cement dispersants.
Summary of the invention
Investigator of the present invention finds through experiment, after polycarboxylic acid super-plasticizer is adsorbed in cement particle surface, due to the strongly hydrophilic of its side chain, cement particle surface is made to form water membrane layer, the lubrication of water film reduces the friction between cement granules, thus reducing concrete viscosity, water film is thicker, and viscosity reducing effect is more remarkable.By improving the sterically hindered effect of polycarboxylic acid super-plasticizer side chain, being conducive to the thickness increasing water film, thus reducing concrete viscosity.And adopt branching type side chain, introduce stiffening ring group simultaneously in the molecule, poly carboxylic acid molecular conformation can be made more to stretch, improve the sterically hindered effect of its side chain further, thus significantly reduce viscosity that is high and super high strength concrete.
In a first aspect of the present invention, provide a kind of preparation method of viscosity reduction type polycarboxylic acid super-plasticizer, by monomer a, monomer b and monomer c in molar ratio (4 ~ 15): 1:(0.5 ~ 2) carry out free radicals copolymerization reaction and obtain, wherein:
The logical formula I of monomer a represents:
R in formula
1for-H or-COOM; R
2for-H ,-CH
3or-CH
2cOOM; And work as R
1during for-COOM, R
2for H; M represents hydrogen atom, alkalimetal ion or ammonium ion;
The logical formula II of monomer b represents:
R in formula
3for-H or-CH
3; R
4for the alkyl of C1 ~ C4; X is-CH
2-,-CH
2oCH
2cH
2-,-CH
2cH
2-,-CH
2cH
2oCH
2cH
2-,-OCH
2cH
2-,-OCH
2cH
2oCH
2cH
2-,-OCH
2cH
2cH
2cH
2-,-C
6h
4-,-C
6h
4cH
2-; M=20 ~ 45, n=5 ~ 10, p=1 ~ 5;
Monomer c is the monomer containing stiffening ring group, be specially NVP, N-caprolactam, 1-vinyl imidazole, 2-vinyl pyridine, 3-vinyl pyridine, 4-vinylpridine, 3-vinyl aniline, 4-vinyl aniline, 3-vinyl benzoic acid, 4-vinyl benzoic acid, 3-vinyl benzyl amine, 4-vinyl benzyl amine, 3-vinylphenylboronic acid, 2-vinylphenylboronic acid or 4-vinylphenylboronic acid, be preferably NVP, N-caprolactam, 1-vinyl imidazole, 2-vinyl pyridine, 3-vinyl pyridine, 4-vinylpridine, 3-vinyl aniline, 4-vinyl aniline, 3-vinyl benzoic acid, 4-vinyl benzoic acid, 3-vinyl benzyl amine or 4-vinyl benzyl amine.
Described monomer a contains at least one material in material represented by logical formula I, and preferably, monomer a is selected from least one in vinylformic acid, methacrylic acid, toxilic acid, fumaric acid or their univalent metal salt, ammonium salt.These monomers are used alone or use with the arbitrary proportion form of mixtures of two or more composition, and its hydroxy-acid group provides adsorption site and electrostatic repulsion in cement dispersants.
Described monomer b can obtain through alkoxylation well known to those skilled in the art, concrete, and monomer b is obtained through blocked alkoxylation by unsaturated alcohol and oxyethane, epoxy terminated alkyl polyoxyethylene glycol,
The logical formula III of described unsaturated alcohol represents:
The logical formula IV of described epoxy terminated alkyl polyoxyethylene glycol represents:
Common unsaturated alcohol comprises 2-propylene-1-alcohol, methallyl alcohol, 2-(2-methyl allyloxy) ethanol, 3-butene-1-ol, 3-methyl-3-butene-1-alcohol, 2-(3-methyl alkene butoxy) ethanol, ethylene glycol vinyl ether, Diethylene Glycol vinyl ether, 4-hydroxy butyl vinyl ether, 4-Vinyl phenol, 4-vinyl benzyl alcohol, preferred unsaturated alcohol comprises 2-propylene-1-alcohol, methallyl alcohol, 2-(2-methyl allyloxy) ethanol, 3-butene-1-ol, 3-methyl-3-butene-1-alcohol, 2-(3-methyl alkene butoxy) ethanol, ethylene glycol vinyl ether, Diethylene Glycol vinyl ether, 4-hydroxy butyl vinyl ether.Common epoxy terminated alkyl polyoxyethylene glycol comprises epoxy terminated methyl polyoxyethylene glycol, epoxy terminated ethyl polyoxyethylene glycol, epoxy terminated propyl group polyoxyethylene glycol, epoxy terminated butyl polyoxyethylene glycol.In order to ensure the good polymerization activity of epoxy terminated polyoxyethylene glycol, its polyoxyethylene adduct number should not be too large, and adduct number is preferably 1 ~ 5.If adduct number is too large, then when reacting, the too high polyoxyethylene chain of molecular weight can cause larger sterically hindered effect to terminal epoxy groups, affects reaction conversion ratio, causes product property to decline.
General described monomer b directly adopts the mixture after alkoxylation, and without the need to purify (because monomer b concentration in mixture is close to 100%, when considering the mol ratio of monomer a, b, c, directly mixture is considered as pure monomer b and calculates).Therefore described blocked alkoxylation actual conditions (selection as catalyzer) can by those skilled in the art in conjunction with as described in the feature of free radicals copolymerization reaction system and the application requiring of target product viscosity reduction type polycarboxylic acid super-plasticizer select.Preferably, described blocked alkoxylation is using potassium, sodium, naphthalene potassium, naphthalene sodium, potassium hydride KH, sodium hydride, alkyl potassium alcoholate, sodium alkyl alcohol, potassium hydroxide or sodium hydroxide as catalyzer, and catalyst levels is 0.1% ~ 0.3% of gained monomer b quality.More preferably adopt following reaction conditions: the temperature of reaction of unsaturated alcohol and oxyethane is 100 ~ 130 DEG C, and reaction pressure is 0.2 ~ 0.4MPa, oxyethane adopts the mode of continuous charging; After oxyethane is reinforced, continue constant temperature to reaction system pressure drop to below-0.05MPa, the mode of continuous charging is adopted to add epoxy terminated alkyl polyoxyethylene glycol again, feed time is 2 ~ 6h, and temperature of reaction is 110 ~ 140 DEG C, and reaction pressure is below-0.05MPa, after reinforced end, constant temperature 0.5 ~ 2h, reaction terminates rear maintenance product temperatur between 60 ~ 80 DEG C, and adopting organic acid to be neutralized to pH value is 6 ~ 8.As this area general knowledge, the applied environment neutralizing organic acid used reply free radicals copolymerization reaction and described viscosity reduction type polycarboxylic acid super-plasticizer is friendly, and preferred described organic acid is any one in Glacial acetic acid, oxalic acid, citric acid, phenylformic acid.
The preparation method of epoxy terminated alkyl polyoxyethylene glycol is the open ripe method of fine chemical fields, those skilled in the art can according to pertinent literature (Guo Limei etc. fine chemistry industry, 2005,22:108-111) method is prepared, and common preparation method is: by epoxy chloropropane and polyalkylene glycol monoalkyl ether, reaction under sodium hydroxide and phase-transfer catalyst exist directly generates epoxy terminated alkyl polyoxyethylene glycol.
The weight average molecular weight range of described viscosity reduction type polycarboxylic acid super-plasticizer is identical with the general requirement of polycarboxylic acid super-plasticizer well known in the prior art, and preferably, the weight-average molecular weight of described polycarboxylic acid super-plasticizer is 10000 ~ 30000.Molecular weight is too large or too little, all can weaken its over-all properties.
Preferably, described free radicals copolymerization reaction is water-based free radical copolyreaction.Preferred, described water-based free radical copolyreaction adopts water soluble starter and water-soluble chain transfer agent, the quality of described water soluble starter and water-soluble chain transfer agent is respectively 0.1% ~ 1%, 0.1% ~ 0.4% of monomer a, monomer b and monomer c three total mass, the polymerization concentration of described water-based free radical copolyreaction is 30% ~ 50%, and wherein polymerization concentration refers to the mass percent concentration sum of all monomers.
Optional water soluble starter comprises independent persulphate, water-soluble azo class initiator, and the composition of oxygenant persulphate and reductive agent hydrosulphite, sulphite, thiosulphate, pyrosulfite or ferrous salt, the composition of oxygenant superoxide and reductive agent formaldehyde sodium sulfoxylate, L-AA, phosphorous acid and salt thereof, Hypophosporous Acid, 50 and salt thereof, wherein in composition, the mole ratio of oxygenant and reductive agent is (4 ~ 8): 1.
Water-soluble chain transfer agent is for controlling poly carboxylic acid molecular weight.Water-soluble chain transfer agent can use mercaptan type chain transfer agent, as 2 mercaptopropionic acid, 3-thiohydracrylic acid, 2-mercaprol, 3-mercaprol, Thiovanic acid, mercaptoethanol, dimercaprol dimercaptopropanol, mistabrom; The secondary alcohols such as Virahol; Phosphorous acid and sodium, sylvite; At least one in Hypophosporous Acid, 50 and sodium thereof, sylvite.
Polymerization concentration in described free radicals copolymerization reaction is preferably 30% ~ 50%, and concentration is too low, and monomer conversion is lower, and production efficiency is low; Excessive concentration, be then polymerized wayward, easily occurs implode gel, have a strong impact on product property.Polymeric reaction temperature is preferably 30 ~ 80 DEG C, and it is main relevant with used initiator, generally, when being used alone persulphate and water-soluble azo class initiator, select slightly high polymerization temperature, and when using redox initiation system, lower polymerization temperature can be selected.
Further preferred, the feed way of described water-based free radical copolyreaction is: monomer b is disposable before other material dropping all to feed intake, the aqueous solution of monomer a and monomer c mix monomer and the aqueous solution of initiator take the mode separately simultaneously dripped to feed in raw material, chain-transfer agent adds in the aqueous solution of mix monomer or the aqueous solution of initiator and drips together, the aqueous solution of mix monomer and the aqueous solution time for adding of initiator are 2 ~ 5h, and the aqueous solution of mix monomer and the aqueous solution of initiator drip follow-up continuation of insurance temperature 1 ~ 4h.
After copolyreaction terminates, reaction product can directly use as the principal constituent of cement dispersants, is more preferably and uses in alkaline matter further and rear use, to strengthen the stability in storage of product.This is the known technology of this area.The alkaline matter used comprises the oxyhydroxide of monovalent metal and/or divalent metal, oxide compound or carbonate, ammonium hydroxide, organic amine.The consumption of alkaline matter is 6 ~ 8 to be advisable to regulate the pH value of reaction product.Because neutralization is very little to the molecular weight effects of described viscosity reduction type polycarboxylic acid super-plasticizer, the present invention ignores it.
According to a second aspect of the invention, the application of described viscosity reduction type polycarboxylic acid super-plasticizer as cement dispersants is provided.
Polycarboxylic acid super-plasticizer of the present invention can directly use as cement dispersants, also composite rear use can be carried out by a certain percentage with the polycarboxylic acid super-plasticizer of the functional type auxiliary agents such as defoamer, air entrapment agent, retardant, thickening material, economization agent or other type, concrete composite type and ratio, engineering technical personnel can according to Practical Project demand by preferred after test.In use, the conventional volume of polycarboxylic acid super-plasticizer of the present invention is 0.05% ~ 0.3% of total gelling material weight.Volume is too low, then can not be satisfactory to the dispersion effect of cement; Volume is too high, cause waste economically, and dispersion effect does not increase further, and engineering staff can be preferred within the scope of this according to practical situation.
Polycarboxylic acid super-plasticizer of the present invention can significantly reduce concrete water-cement ratio, and effectively can reduce viscosity that is high and super high strength concrete, and improve its workability and velocity of flow, pumpability is excellent, and more conventional polycarboxylic acid super-plasticizer has significant advantage.
Embodiment
In order to understand the present invention better, illustrate content of the present invention further below in conjunction with embodiment, but content of the present invention is not only confined to the following examples.
In the embodiment of the present invention, the test of transformation efficiency adopts the LC600 high performance liquid chromatograph (HPLC) of LabTech to carry out.Test condition is, chromatographic column adopts KromasilC18 post, and moving phase is CH
3oH/H
2o=80/20 (v/v), flow velocity is 0.6ml/min, and detector is differential refraction detector, detector temperature 35 DEG C, and sample size is the aqueous solution of 20 μ l0.5% samples.
In the embodiment of the present invention, the weight-average molecular weight of polymkeric substance adopts Agilent-1260 gel permeation chromatograph (GPC) to measure.Test condition is, gel column: ShodexSB806+803 two root chromatogram column is connected; Eluant: 0.1MNaNO
3solution; Moving phase speed: 0.8ml/min; Injection: the aqueous solution of 20 μ l0.5% samples; Detector: differential refraction detector; Standard substance: polyoxyethylene glycol GPC standard specimen (Sigma-Aldrich, molecular weight 1010000,478000,263000,118000,44700,18600,6690,1960,628,232).
The raw material used in the embodiment of the present invention is commercially available general analysis pure chemistry reagent, and oxyethane is the premium grads of three river Chemical Manufacture, purity 99.95%.
The preparation of monomer b
The preparation of epoxy terminated alkyl polyoxyethylene glycol:
The epoxy chloropropane of 0.5mol is added in the there-necked flask that band stirs, the sodium hydroxide of 0.2mol, the phase-transfer catalyst 4-n-butyl ammonium hydrogen sulfate of 0.005mol, mono-alkyl polyethylene glycol constant temperature 60 DEG C of rapid stirring 5h of 0.05mol, filter, filtrate removes excessive epoxy chloropropane through underpressure distillation, the transformation efficiency that product tests mono-alkyl polyethylene glycol through HPLC is 85% ~ 90%, product adopts silica gel column chromatography (ethyl acetate is eluent) to carry out separating-purifying again, obtain purity be greater than 99% epoxy terminated alkyl polyoxyethylene glycol.
Epoxy terminated alkyl polyoxyethylene glycol prepared by table 1 gathers
Code |
Title |
End group type |
p |
Molecular weight |
E-1 |
Epoxy terminated methyl polyoxyethylene glycol |
Methyl |
1 |
132 |
E-2 |
Epoxy terminated propyl group polyoxyethylene glycol |
Propyl group |
3 |
248 |
E-3 |
Epoxy terminated butyl polyoxyethylene glycol |
Butyl |
4 |
306 |
E-4 |
Epoxy terminated methyl polyoxyethylene glycol |
Methyl |
5 |
308 |
E-5 |
Epoxy terminated propyl group polyoxyethylene glycol |
Propyl group |
2 |
204 |
The preparation of monomer b-1:
In the 2L reactor with the drying of stirring, add 62.5g2-propylene-1-alcohol, 4.99g sodium methylate, unlatching is stirred to sodium methylate and dissolves completely, sealed reactor.Be repeated below operation twice: after nitrogen replacement, be evacuated to below-0.09MPa.Then Keep agitation after being warming up to 120 ~ 130 DEG C, slowly at the uniform velocity drips 948.28g oxyethane continuously in reactor, maintains reaction pressure 0.3 ~ 0.4MPa.After the reinforced end of constant temperature, continue constant temperature and keep system pressure drop to below-0.05MPa, then in reactor, slowly at the uniform velocity drip 711.21gE-1 continuously, feed time is 2h, keeps temperature of reaction 130 ~ 140 DEG C simultaneously.After reinforced end, continue constant temperature and keep 2h, being neutralized to pH value with Glacial acetic acid after being cooled to 60 DEG C is about 7, and discharging obtains monomer b-1, and it is 99.5% that HPLC tests transformation efficiency, and molecular weight is 1598.
The preparation of monomer b-2:
In the 2L reactor with the drying of stirring, add 38.6g2-methyl-2-propylene-1-alcohol, 3.71g sodium hydride, unlatching is stirred to sodium hydride and dissolves completely, sealed reactor.Be repeated below operation twice: after nitrogen replacement, be evacuated to below-0.09MPa.Then Keep agitation after being warming up to 100 ~ 110 DEG C, slowly at the uniform velocity drips 754.84g oxyethane continuously in reactor, maintains reaction pressure 0.25 ~ 0.35MPa.After the reinforced end of constant temperature, continue constant temperature and keep system pressure drop to below-0.06MPa, then in reactor, slowly at the uniform velocity drip 1063.64gE-2 continuously, feed time is 6h, keeps temperature of reaction 110 ~ 120 DEG C simultaneously.After reinforced end, continue constant temperature and keep 2h, being neutralized to pH value with phenylformic acid after being cooled to 80 DEG C is about 7, and discharging obtains monomer b-2, and it is 99.1% that HPLC tests transformation efficiency, and molecular weight is 3464.
The preparation of monomer b-3:
In the 2L reactor with the drying of stirring, add 56.2g2-(2-methyl allyloxy) ethanol, 2.7g potassium ethylate, unlatching is stirred to potassium ethylate and dissolves completely, sealed reactor.Be repeated below operation twice: after nitrogen replacement, be evacuated to below-0.09MPa.Then Keep agitation after being warming up to 105 ~ 115 DEG C, slowly at the uniform velocity drips 852.69g oxyethane continuously in reactor, maintains reaction pressure 0.2 ~ 0.3MPa.After the reinforced end of constant temperature, continue constant temperature and keep system pressure drop to below-0.06MPa, then in reactor, slowly at the uniform velocity drip 889.51gE-3 continuously, feed time is 5h, keeps temperature of reaction 120 ~ 130 DEG C simultaneously.After reinforced end, continue constant temperature and keep 2h, being neutralized to pH value with phenylformic acid after being cooled to 70 DEG C is about 7, and discharging obtains monomer b-3, and it is 99.5% that HPLC tests transformation efficiency, and molecular weight is 3712.
The preparation of monomer b-4:
In the 2L reactor with the drying of stirring, add 28.6g3-methyl-3-butene-1-alcohol, 1.71g sodium Metal 99.5, unlatching is stirred to sodium Metal 99.5 and dissolves completely, sealed reactor.Be repeated below operation twice: after nitrogen replacement, be evacuated to below-0.09MPa.Then Keep agitation after being warming up to 110 ~ 120 DEG C, slowly at the uniform velocity drips 658.47g oxyethane continuously in reactor, maintains reaction pressure 0.25 ~ 0.35MPa.After the reinforced end of constant temperature, continue constant temperature and keep system pressure drop to below-0.05MPa, then in reactor, slowly at the uniform velocity drip 1024.28gE-4 continuously, feed time is 5h, keeps temperature of reaction 125 ~ 135 DEG C simultaneously.After reinforced end, continue constant temperature and keep 2h, being neutralized to pH value with Glacial acetic acid after being cooled to 65 DEG C is about 7, and discharging obtains monomer b-4, and it is 99.2% that HPLC tests transformation efficiency, and molecular weight is 5146.
The preparation of monomer b-5:
In the 2L reactor with the drying of stirring, add 79.5g4-hydroxy butyl vinyl ether, 4.26g potassium hydroxide, unlatching is stirred to potassium hydroxide and dissolves completely, sealed reactor.Be repeated below operation twice: after nitrogen replacement, be evacuated to below-0.09MPa.Then Keep agitation after being warming up to 110 ~ 120 DEG C, slowly at the uniform velocity drips 784.03g oxyethane continuously in reactor, maintains reaction pressure 0.2 ~ 0.3MPa.After the reinforced end of constant temperature, continue constant temperature and keep system pressure drop to below-0.055MPa, then in reactor, slowly at the uniform velocity drip 838.86gE-5 continuously, feed time is 4h, keeps temperature of reaction 115 ~ 125 DEG C simultaneously.After reinforced end, continue constant temperature and keep 0.5h, being neutralized to pH value with Glacial acetic acid after being cooled to 60 DEG C is about 7, and discharging obtains monomer b-5, and it is 99.3% that HPLC tests transformation efficiency, and molecular weight is 2484.
Monomer b molecular structure information prepared by table 2 gathers
[embodiment 1]
In the present embodiment, the molar ratio of monomer a, monomer b and monomer c is 4:1:0.5.
In the 1L glass reactor that thermometer, agitator, dropping funnel and nitrogen conduit are housed, add 191g distilled water and 286.5g monomer b-1.Reactor is under logical nitrogen protection; be stirred to and dissolve completely; and be warming up to 80 DEG C; then 51.63g vinylformic acid, 9.95gN-vinyl pyrrolidone, 0.35g3-thiohydracrylic acid and 67g water mix and blend are made uniform monomer solution; it at the uniform velocity dropped in reactor, time for adding is 5h.Meanwhile, at the uniform velocity drip the initiator solution mixed by 0.35g ammonium persulphate and 86g water, time for adding is 5h.After complete soln dropwises, continue constant temperature and keep 4h, be then cooled to 40 DEG C, with sodium hydroxide, product be neutralized to about pH=7, obtain the viscosity reduction type polycarboxylic acid super-plasticizer that solid content is 49.8%, molecular weight is determined as 10 through GPC, and 600.
[embodiment 2]
In the present embodiment, the molar ratio of monomer a, monomer b and monomer c is 6.7:1:1.85.
In the 1L glass reactor that thermometer, agitator, dropping funnel and nitrogen conduit are housed, add 164g distilled water and 245.5g monomer b-2.Reactor is under logical nitrogen protection; be stirred to and dissolve completely; and be warming up to 75 DEG C; then 28.07g vinylformic acid, 9.14g sodium methacrylate, 13.77g4-vinyl pyridine, 0.59g mercaptoethanol and 87g water mix and blend are made uniform monomer solution; it at the uniform velocity dropped in reactor, time for adding is 4h.Meanwhile, at the uniform velocity drip the initiator solution mixed by 1.48g Potassium Persulphate and 105g water, time for adding is 4h.After complete soln dropwises, continue constant temperature and keep 3h, be then cooled to 40 DEG C, with potassium hydroxide, product be neutralized to about pH=7, obtain the viscosity reduction type polycarboxylic acid super-plasticizer that solid content is 45.8%, molecular weight is determined as 15 through GPC, and 700.
[embodiment 3]
In the present embodiment, the molar ratio of monomer a, monomer b and monomer c is 9.5:1:1.2.
In the 1L glass reactor that thermometer, agitator, dropping funnel and nitrogen conduit are housed, add 143.5g distilled water and 215.3g monomer b-3.Reactor is under logical nitrogen protection; be stirred to and dissolve completely; and be warming up to 65 DEG C; then 43.73g toxilic acid, 16.36g sodium acrylate, 9.67gN-caprolactam, 0.71g Thiovanic acid and 120g water mix and blend are made uniform monomer solution; it at the uniform velocity dropped in reactor, time for adding is 4h.Meanwhile, at the uniform velocity drip the initiator solution mixed by 1.85g azo diisobutyl amidine hydrochloride and 158g water, time for adding is 4h.After complete soln dropwises, continue constant temperature and keep 2h, be then cooled to 40 DEG C, with triethylamine, product be neutralized to about pH=7, obtain the viscosity reduction type polycarboxylic acid super-plasticizer that solid content is 40.5%, molecular weight is determined as 24 through GPC, and 800.
[embodiment 4]
In the present embodiment, the molar ratio of monomer a, monomer b and monomer c is 15:1:2.
In the 1L glass reactor that thermometer, agitator, dropping funnel and nitrogen conduit are housed, add 124g distilled water and 186.2g monomer b-4.Reactor is under logical nitrogen protection; be stirred to and dissolve completely; and be warming up to 45 DEG C; then 29.96g vinylformic acid, 14.69g fumaric acid, 9.62g4-vinyl benzyl amine, 2.16g sodium bisulfite, 0.96g sodium hypophosphite and 185g water mix and blend are made uniform monomer solution; it at the uniform velocity dropped in reactor, time for adding is 3h.Meanwhile, at the uniform velocity drip the initiator solution mixed by 0.21g Sodium Persulfate and 236g water, time for adding is 3h.After complete soln dropwises, continue constant temperature and keep 4h, be then cooled to 40 DEG C, with sodium hydroxide, product be neutralized to about pH=7, obtain the viscosity reduction type polycarboxylic acid super-plasticizer that solid content is 30.9%, molecular weight is determined as 29 through GPC, and 600.
[embodiment 5]
In the present embodiment, the molar ratio of monomer a, monomer b and monomer c is 10:1:0.75.
In the 1L glass reactor that thermometer, agitator, dropping funnel and nitrogen conduit are housed, add 116.5g distilled water and 174.8g monomer b-5.Reactor is under logical nitrogen protection; be stirred to and dissolve completely; and be warming up to 30 DEG C; then 22.8g vinylformic acid, 53.41g toxilic acid list sodium, 7.81g4-vinyl benzoic acid, 0.91g3-mercaprol, 2.59g formaldehyde sodium sulfoxylate and 114g water mix and blend are made uniform monomer solution; it at the uniform velocity dropped in reactor, time for adding is 2h.Meanwhile, at the uniform velocity drip the initiator solution mixed by 0.94g hydrogen peroxide and 70g water, time for adding is 2h.After complete soln dropwises, continue constant temperature and keep 2h, then with triethylamine, product is neutralized to about pH=7, obtain the viscosity reduction type polycarboxylic acid super-plasticizer that solid content is 36.2%, molecular weight is determined as 18 through GPC, and 500.
[embodiment 6]
In the present embodiment, the molar ratio of monomer a, monomer b and monomer c is 6.2:1:1.45.
In the 1L glass reactor that thermometer, agitator, dropping funnel and nitrogen conduit are housed, add 160.8g distilled water and 241.3g monomer b-2.Reactor is under logical nitrogen protection; be stirred to and dissolve completely; and be warming up to 55 DEG C; then 31.1g vinylformic acid, 11.21gN-vinyl pyrrolidone, 0.85g2-mercaprol and 105g water mix and blend are made uniform monomer solution; it at the uniform velocity dropped in reactor, time for adding is 4h.Meanwhile, at the uniform velocity drip the initiator solution mixed by 2.41g azo diisobutyl imidazoline hydrochloride and 144g water, time for adding is 4.5h.After complete soln dropwises, continue constant temperature and keep 2.5h, be then cooled to 40 DEG C, with sodium hydroxide, product be neutralized to about pH=7, obtain the viscosity reduction type polycarboxylic acid super-plasticizer that solid content is 40.3%, molecular weight is determined as 22 through GPC, and 600.
[comparative example 1]
In the 1L glass reactor that thermometer, agitator, dropping funnel and nitrogen conduit are housed, add the allyl polyglycol polymeric monomer that 191g distilled water and the commercially available convenient molecular weight of 286.5g are 2400.Reactor is under logical nitrogen protection; be stirred to and dissolve completely; and be warming up to 80 DEG C; then 51.63g vinylformic acid, 9.95gN-vinyl pyrrolidone, 0.35g3-thiohydracrylic acid and 67g water mix and blend are made uniform monomer solution; it at the uniform velocity dropped in reactor, time for adding is 5h.Meanwhile, at the uniform velocity drip the initiator solution mixed by 0.35g ammonium persulphate and 86g water, time for adding is 5h.After complete soln dropwises, continue constant temperature and keep 4h, be then cooled to 40 DEG C, with sodium hydroxide, product be neutralized to about pH=7, obtain the polycarboxylic acid super-plasticizer that solid content is 49.4%, molecular weight is determined as 21 through GPC, and 500.
[comparative example 2]
In the 1L glass reactor that thermometer, agitator, dropping funnel and nitrogen conduit are housed, add the methyl butene base polyoxyethylene glycol polymeric monomer that 124g distilled water and the commercially available convenient molecular weight of 186.2g are 2400.Reactor is under logical nitrogen protection; be stirred to and dissolve completely; and be warming up to 45 DEG C; then 29.96g vinylformic acid, 14.69g fumaric acid, 9.62g4-vinyl benzyl amine, 2.16g sodium bisulfite, 0.96g sodium hypophosphite and 185g water mix and blend are made uniform monomer solution; it at the uniform velocity dropped in reactor, time for adding is 3h.Meanwhile, at the uniform velocity drip the initiator solution mixed by 0.21g Sodium Persulfate and 236g water, time for adding is 3h.After complete soln dropwises, continue constant temperature and keep 4h, be then cooled to 40 DEG C, with sodium hydroxide, product be neutralized to about pH=7, obtain the polycarboxylic acid super-plasticizer that solid content is 31.8%, molecular weight is determined as 34 through GPC, and 200.
Viscosity reduction type polycarboxylic acid super-plasticizer prepared by Evaluation operation example 1 ~ 6 and polycarboxylic acid super-plasticizer prepared by comparative example 1 ~ 2, on the impact of fresh mixing concrete property, perform with reference to standard GB/T 8076-2008 " concrete admixture " relevant regulations.Test is carried out under 20 DEG C of environment, and test cement adopts little Ye field, south of the River P. II 52.5 cement, and the same water consumption of stationary phase (water-cement ratio is 0.27), proportioning is in table 3.Adjustment admixture dosage makes fresh concrete initial slump be 23 ± 1cm, flowing time (hereinafter referred to as T50) when adopting initial concrete divergence to be 50cm and the initial bucket of falling slump emptying time weigh concrete viscosity, both used times are fewer, show that concrete viscosity is lower, the viscosity reducing effect of admixture is more remarkable.The volume of admixture is pure solid volume, with the total mass of gelling material for benchmark.Result is as shown in table 4.
Table 3C70 mix proportion of high-strength concrete (kg/m
3)
Cement |
Flyash |
Breeze |
Sand |
Gravelstone |
Great Shi |
Water |
Water-cement ratio |
4.95 |
2.06 |
1.25 |
10.99 |
4.56 |
10.62 |
2.23 |
0.27 |
Properties of High Strength Concrete contrast newly mixed by table 4
As can be seen from result shown in table 4, in the concrete application of C70, compare with the polycarboxylic acid super-plasticizer prepared by comparative example 2 with use comparative example 1, the viscosity reduction type polycarboxylic acid super-plasticizer of use prepared by embodiment 1 ~ 6 is under substantially suitable initial slump and divergence situation, volume has and significantly reduces, initial water-reducing effect is remarkable, and 60min slump-loss is also obviously better than comparative example 1 and 2 simultaneously.From viscosity test data, viscosity reduction type polycarboxylic acid super-plasticizer prepared by embodiment 1 ~ 6 is used for concrete initial extension degree flowing time T50 substantially all at about 15s, the bucket of falling slump emptying time is between 11 ~ 14s, and the T50 flowing time of comparative example 1 and 2 reaches more than 21s, the bucket of falling slump emptying time reaches about 30s, viscosity reduction type polycarboxylic acid super-plasticizer prepared by the visible embodiment of the present invention 1 ~ 6 significantly can reduce the viscosity of high-strength concrete, and effect is remarkable.