It is a kind of to coagulate high dispersive polycarboxylic acid super-plasticizer and its preparation method and application at a low speed
Technical field
The invention belongs to super plasticizer fields, and in particular to a kind of to coagulate high dispersive polycarboxylic acid super-plasticizer and its preparation at a low speed
Methods and applications.
Background technique
Polycarboxylate high performance water-reducing agent largely uses in ceramics, cement and plastering field, to positively charged
Particle not only has suction-operated, and there are also space steric effects.For cement granules, the anti-of cement and mixing water can be increased
Contact surface is answered, and increases aquation film thickness at hydration reaction initial stage, hinders the release of cement granules intermediate ion, keeps hydration reaction fast
Degree reduces, and shows deferred action.
However, in the production process of precast concrete, concrete job mix cast in situs needs not move through one
The process of a long-distance transportation, such deferred action are unfavorable for the raising of precast concrete production efficiency.
In order to accelerate form cycling rate or reduce template using total amount, production efficiency is improved, realizes maximum economy
Benefit needs to promote using the method for addition early strength agent cooperation steam curing process shield usually while using polycarboxylate water-reducer
Into hydrated cementitious and condensation.
Most of early strength agent has the effect of improving early strong intensity, and the slow setting of poly carboxylic acid series water reducer cannot but be inhibited to make
With.The larger rush that can just play of the inorganic general volume of early strength agent coagulates effect, bad with the compatibility of poly carboxylic acid series water reducer, is easy to divide
Fleece is solidifying, and cannot play the due peptizaiton of polycarboxylate water-reducer, and wherein villaumite but will Corrosion Reinforcement;Organic Alcohol amine is mixed
Amount and to promote solidifying effect not easy to control, bad adaptability and expensive.
In addition, having part research to report through macromolecular structure improvement reaches promotion hydrated cementitious, such as on main chain
Some function monomers without suction-operated are simply introduced, but such consequence will certainly weaken the dispersion performance of water-reducing agent.
Chinese patent CN103304181A discloses a kind of high performance water reducing agent of polyocarboxy acid, composition and by weight percentage
It is as follows: poly carboxylic acid series water reducer 10~20%, calcium chloride 10~17%, sodium nitrite 10~20%, triethanolamine 1~3%,
Yu Weishui.The water-reducing agent is to be obtained on the basis of common polycarboxylate water-reducer by compounding, and advantage is that concrete can be improved
The early strength of product, but not from molecular structure inhibit polycarboxylate water-reducer deferred action, adaptability is bad, be easy point
Fleece is solidifying, and the volume of additive is higher.
Chinese patent CN200810201010.6 proposes a kind of poly carboxylic acid series water reducer, and preparation process is to use poly- second
Glycol monomethyl ether methacrylate or monomethyl polyethylene glycol acrylate ester (degree of polymerization is between 20~60), (methyl) propylene
Acid, (methyl) Sodium Allyl Sulfonate, alkoxy polyethylene glycol (polypropylene glycol) acrylate are copolymerized in aqueous solution.The water-reducing agent
With certain promotion cement setting effect, but two kinds of esters monomers are both needed to react to obtain by high temperature esterification, and reaction process is multiple
It is miscellaneous, it takes a long time, and polymerization inhibitor remaining in reaction process has certain influence to secondary polymerization reaction.
World patent WO2011/076655A1 reports a kind of polycarboxylic acid super-plasticizer, and preparation method is to use poly- third
Olefin(e) acid (molecular weight 4000) and poly glycol monomethyl ether (molecular weight 5000), after being esterified at 165 DEG C in and obtain.The party
Method can also effectively shorten the setting time of concrete, but need first to synthesize polyacrylic acid, and preparation difficulty is larger, higher cost,
Secondly viscosity is larger, lower with the conversion rate of esterification of polyethers, thus the volume of additive is relatively high, and cost performance is low.
In recent years, the continuous speedup of domestic investment, infrastructure construction dynamics and scale also continue to increase, precast concrete
Dosage is also constantly soaring.A kind of polycarboxylic acid super-plasticizer with low and slow solidifying high dispersive effect is developed to improve precast concrete row
The production efficiency of industry is of great significance to promotion building material industry energy-saving and emission-reduction.
Summary of the invention
In order to solve the above-mentioned technical problem, the primary purpose of the present invention is that provide a kind of high dispersive polycarboxylic acids solidifying at a low speed super
The preparation method of plasticiser.
Another object of the present invention is to provide a kind of low and slow solidifying high dispersive polycarboxylic acids being prepared by the above method
Super plasticizer.
A further object of the present invention is to provide above-mentioned high dispersive polycarboxylic acid super-plasticizers solidifying at a low speed in ceramics, cement, stone
Application in cream production of articles.
The object of the invention is achieved through the following technical solutions:
A kind of preparation method of high dispersive polycarboxylic acid super-plasticizer solidifying at a low speed, including following preparation step:
Polyether macromonomer A, initiator and water are added in reactor, stirred under nitrogen atmosphere is uniformly mixed, together
When be heated to 10~100 DEG C, then respectively be added dropwise small molecule monomer B, reducing agent and chain-transferring agent aqueous solution, after being added dropwise to complete
1~6h of insulation reaction is neutralized, and obtains the high dispersive polycarboxylic acid super-plasticizer solidifying at a low speed;
Wherein, polyether macromonomer A has structural formula shown in formula (1):
In formula: R1For-H or the alkyl of carbon atom number 1~5, R2For carbonyl or the alkyl of carbon atom number 1~10, R3For-H or
The alkyl of carbon atom number 1~5, n and m are respectively the average addition molal quantity of ethylene oxide and propylene oxide chain link, wherein n=10
~200, m=0~40;
Small molecule monomer B refer to acrylic acid (AA), 2- acrylamide-2-methyl propane sulfonic (AMPS), methacrylic acid (MA),
At least one of acrylamide (AM), maleic anhydride (MAH), itaconic acid (IA);
The chain-transferring agent refers to glycol dimercaptoacetate, double thioacetic acid trihydroxymethylpropanyl esters, double sulfydryls
At least one of pentaerythritol tetraacetate, double mercaptopropionic acid mesoinositols, the dosage of the chain-transferring agent be macromonomer A and
The 0.1%~3% of small molecule monomer B gross mass.
Preferably, the mass ratio of the polyether macromonomer A and small molecule monomer B is (85~97): (3~15).
Preferably, the initiator includes ammonium persulfate, potassium peroxydisulfate, sodium peroxydisulfate, hydrogen peroxide and benzoyl peroxide first
At least one of acyl, the dosage of initiator are the 0.1%~2% of macromonomer A and small molecule monomer B gross mass.
Preferably, the reducing agent include rongalite, bisulfites, sulphite, thiosulfate,
At least one of pyrosulfite, ascorbic acid and ferrous salt, the dosage of reducing agent are macromonomer A and small molecule monomer
The 0.01%~1% of B gross mass.
Preferably, the time of the aqueous solution that small molecule monomer B, reducing agent and chain-transferring agent is added dropwise is 2~4h.
Preferably, the neutralization refers to is neutralized using dilute alkaline soln, and the dilute alkaline soln refers to that mass concentration is
10%~40% NaOH, KOH, hexamethylene diamine or triethanolamine solution.
A kind of high dispersive polycarboxylic acid super-plasticizer solidifying at a low speed, is prepared by the above method.The super modeling that the present invention obtains
Agent is colourless or light yellow transparent liquid.
Application of the above-mentioned high dispersive polycarboxylic acid super-plasticizer solidifying at a low speed in ceramics, cement, plastering production, application
When folding consolidate volume be 0.05%~0.3%.
The schematic arrangement that gained of the invention coagulates high dispersive polycarboxylic acid super-plasticizer at a low speed is as shown in Figure 1.
Polycarboxylate water-reducer is the space steric effect of electrostatic interaction and combed branch based on negative electrical charge functional group, is made
It has excellent dispersion performance to cement and clay particle.Usual adsorbance is bigger, and deferred action is stronger.The present invention is guaranteeing
Under the premise of polycarboxylate water-reducer excellent initial stage dispersion effect, by reducing the adsorbance to cement or clay particle, thus
Achieve the purpose that inhibit deferred action.
Novel polycarboxylic acid super-plasticizer provided by the invention is adjusted from macromolecular structure.Subtract with common polycarboxylic acids
Aqua the difference is that, by using double sulfydryl esters transfer agents, two ester groups are introduced on main chain center,
Middle main chain configuration is straight chain type structure, and by the adjustment to reaction system, the main chain of polymer is shorter, and side chain is longer.Although
Backbone length shortens, and negative electrical charge functional group tails off, and weakens to the electrostatic adsorption of cement granules, but by increasing branch chain length
Degree enhances space steric effect, ensures that the peptizaiton of plasticiser is not only stronger instead without reducing in this way, and cement
The polymer barrier layer on grain surface is thicker, and the aquation gap between polymer is bigger, is conducive to the progress of aquation, and present invention gained is low
Slow setting high dispersive polycarboxylic acid super-plasticizer is as shown in Figure 2 to the adsorbed state schematic diagram of cement granules.
Secondly, the ester group on main chain can be hydrolyzed gradually in alkaline environment, fracture drop can occur for main chain in hydration process
Solution, makes the Electrostatic Absorption group in single macromolecular tail off, and later period suction-operated weakens significantly, and the slow setting of polycarboxylate water-reducer is made
With being further restricted.Hydrated cementitious speed is accelerated, and not only shortens setting time, is even more conducive to the hair of early strength
Exhibition, thus have broad application prospects in precast concrete field.
For the present invention with unsaturated carboxylic acid/sulfonate, high molecular weight unsaturated polyether is that monomer carries out water phase free radical polymerization,
Ester group is introduced on polymeric carbon chain by special chain-transferring agent, prepares the degradable poly carboxylic of a kind of short main chain, long side chain
Sour super plasticizer.The poly carboxylic acid series super plasticizer of latest generation provides the method that much can change polymer architecture, makes spy
The polymer not designed is possibly realized for changing adsorbed state, realizes macromolecular to water by adjusting its master/side chain configuration
The controllable adsorption of mud component, had not only maintained the high dispersive effect of common polycarboxylic acid super-plasticizer, but also can inhibit it to the greatest extent
Deferred action, the concrete for making poly carboxylic acid series super plasticizer be more particularly for production and the early solidifying requirement of precast concrete are applied
Work.
Compared with the existing technology, the invention has the following advantages and beneficial effects:
(1) polycarboxylic acid super-plasticizer prepared by the present invention is by using special chain-transferring agent, in main chain center
Two ester groups of upper introducing, ester group can be hydrolyzed gradually in alkaline environment, and fracture degradation can occur for main chain in hydration process, make list
Electrostatic Absorption group in a macromolecular tails off, and later period suction-operated thus weakens significantly;
(2) polycarboxylic acid super-plasticizer preparation method of the invention is simple, and water-reducing rate is high, dispersion performance is excellent, and when application makes
Hydrated cementitious speed is fast, setting time is short, and early strength is high, has broad application prospects in precast concrete field;
(3) polycarboxylic acid super-plasticizer of the invention such as appropriately uses in precast concrete, may replace process it is cumbersome two
Secondary maintaining process avoids the potential high-risk of secondary maintenance, and a large amount of consumption steam coal resources.
Detailed description of the invention
Fig. 1 is the schematic arrangement that present invention gained coagulates high dispersive polycarboxylic acid super-plasticizer at a low speed;
Fig. 2 is present invention gained adsorbed state schematic diagram of the solidifying high dispersive polycarboxylic acid super-plasticizer to cement granules at a low speed;
Fig. 3 is that the hydration heat rate comparison of comparative sample 1 obtained by 4 gained PCE-4 of the embodiment of the present invention and comparative example is tested
Curve graph.
Specific embodiment
Below with reference to embodiment, the present invention is described in further detail, and embodiments of the present invention are not limited thereto.
Raw material code name is as shown in table 1 in following embodiment and comparative example:
Table 1
A-1 |
Isopentene group polyoxyethylene ether (Mn=6000) |
C-1 |
Ammonium persulfate |
A-2 |
Methyl allyl polyoxyethylene ether (Mn=4000) |
C-2 |
Hydrogen peroxide (35%) |
A-3 |
Methyl allyl polyoxyethylene ether (Mn=2400) |
D-1 |
Ascorbic acid |
B-1 |
Acrylic acid |
D-2 |
Rongalite |
B-2 |
Acrylamide |
E-1 |
Glycol dimercaptoacetate |
B-3 |
2- acrylamide-2-methyl propane sulfonic |
E-2 |
Thioacetic acid |
Embodiment 1
77.8g is sequentially added in the 250mL four-hole boiling flask that blender, thermometer, nitrogen ingress pipe, Dropping feeder are housed
Water, 71.8g A-1 are warming up to 85 DEG C under nitrogen protection, are stirring evenly and then adding into 1.6g C-1, are stirred for 10min, drip respectively
The aqueous solution of 7.5g B-1 and 0.01g D-1,0.44g E-1 is added, time for adding is respectively 2h and 2.5h, is protected after being added dropwise
Temperature reaction 1.5h, after reaction, slow cooling is to 40 DEG C, sodium hydroxide solution that obtained product mass concentration is 30%
PH value is adjusted to 5 or so.It is cooled to room temperature, is diluted with water to obtain the low and slow solidifying super modeling of high dispersive polycarboxylic acids that mass concentration is 40%
Agent is labeled as PCE-1.
Embodiment 2
79.1g is sequentially added in the 250mL four-hole boiling flask that blender, thermometer, nitrogen ingress pipe, Dropping feeder are housed
Water, 70.7g A-2 are warming up to 65 DEG C under nitrogen protection, are stirring evenly and then adding into 0.3g C-1, are stirred for 10min, drip respectively
The aqueous solution of 7.5g B-1,1.2g B-2 and 0.01g D-1,0.52g E-1 is added, time for adding is respectively 2.5h and 3h, drop
Insulation reaction 1.5h after adding, after reaction, slow cooling is to 40 DEG C, hydrogen that obtained product mass concentration is 30%
Sodium hydroxide solution adjusts pH value to 5 or so.It is cooled to room temperature, is diluted with water to obtain the low and slow solidifying high dispersive that mass concentration is 40%
Polycarboxylic acid super-plasticizer is labeled as PCE-2.
Embodiment 3
76.8g is sequentially added in the 250mL four-hole boiling flask that blender, thermometer, nitrogen ingress pipe, Dropping feeder are housed
Water, 72.8g A-3 are warming up to 45 DEG C under nitrogen protection, are stirring evenly and then adding into 0.68g C-2, are stirred for 10min, respectively
It is added dropwise to the aqueous solution of 6.5g B-1 and 0.12g D-1,0.36g E-1, time for adding is respectively 3h and 3.5h, after being added dropwise
Insulation reaction 1h, after reaction, slow cooling is to 40 DEG C, sodium hydroxide solution that obtained product mass concentration is 30%
PH value is adjusted to 5 or so.It is cooled to room temperature, is diluted with water to obtain the low and slow solidifying super modeling of high dispersive polycarboxylic acids that mass concentration is 40%
Agent is labeled as PCE-3.
Embodiment 4
76.1g is sequentially added in the 250mL four-hole boiling flask that blender, thermometer, nitrogen ingress pipe, Dropping feeder are housed
Water, 73.8g A-1 are warming up to 25 DEG C under nitrogen protection, are stirring evenly and then adding into 0.48g C-2, are stirred for 10min, respectively
It is added dropwise to the aqueous solution of 5.5g B-1 and 0.20g D-2,0.60g E-1, time for adding is respectively 3.5h and 4h, after being added dropwise
Insulation reaction 1h, after reaction, the sodium hydroxide solution that obtained product mass concentration is 30% adjust pH value to 5 left sides
It is right.It is cooled to room temperature, is diluted with water to obtain the low and slow solidifying high dispersive polycarboxylic acid super-plasticizer that mass concentration is 40%, be labeled as
PCE-4。
Embodiment 5
81.1g is sequentially added in the 250mL four-hole boiling flask that blender, thermometer, nitrogen ingress pipe, Dropping feeder are housed
Water, 67.5g A-2 are warming up to 25 DEG C under nitrogen protection, are stirring evenly and then adding into 0.52g C-2, are stirred for 10min, respectively
It is added dropwise to the aqueous solution of 5.4g B-1,6.4g B-3 and 0.24g D-2,0.48g E-1, time for adding is respectively 3h and 3.5h,
Rear insulation reaction 1h is added dropwise, after reaction, the sodium hydroxide solution that obtained product mass concentration is 30% is adjusted
PH value is to 5 or so.It is cooled to room temperature, being diluted with water to obtain mass concentration is that coagulate high dispersive polycarboxylic acids super plasticized for 40% low and slow
Agent is labeled as PCE-5.Comparative example
76.8g water, 72.8g A- are sequentially added in the 250mL four-hole boiling flask that blender, thermometer, Dropping feeder are housed
3,65 DEG C are warming up to, 0.30g C-2 is stirring evenly and then adding into, is stirred for 10min, is added dropwise to 6.5g B-1 and 0.12g D- respectively
1, the aqueous solution of 0.32g E-2, time for adding are respectively 3h and 3.5h, and rear insulation reaction 1.5h is added dropwise, after reaction,
For slow cooling to 40 DEG C, the sodium hydroxide solution that obtained product mass concentration is 30% adjusts pH value to 5 or so.It is cooled to
Room temperature is diluted with water to obtain the polycarboxylic acid super-plasticizer that mass concentration is 40%, is labeled as comparative sample 1.
Implementation result:
Using reference cement, comparative sample 1 is medium-sized polycarboxylic acid super-plasticizer, according to GB/T8077-2000 " concrete
Additive homogeneity test method " test cement paste flowing degree, the volume of the ratio of mud 0.35, water-reducing agent (rolls over solid volume
0.1%) on the basis of the quality of cement, test result is as follows shown in table 2.
2 paste flowing degree test result of table
By the above results as can be seen that relative to plain edition polycarboxylate water-reducer (comparative example 1), prepared by the present invention
The paste flowing degree of solidifying high dispersive polycarboxylic acid super-plasticizer and water-reducing rate are higher at a low speed, have better initial dispersion to cement
Performance, and initial set and final setting time also have different degrees of shortening than plain edition polycarboxylate water-reducer.
It chooses PCE-4 and comparative sample 1 carries out the test of hydration heat rate comparison.The TAM Air of TA company of U.S. production
The micro- calorimeter of 08Isothermal Calorimeter isothermal, the ratio of mud 0.4, polycarboxylate water-reducer roll over solid volume 0.2%.Institute
There is material first to stir 1min with 500r/min, then 1min is stirred with 1500r/min, controlled at 20 ± 0.1 DEG C, aquation is put
Hot rate curve is as shown in Figure 3.It can be seen that compared with plain edition polycarboxylic acids (comparative example 1) from hydration heat curve, mix this hair
When bright gained coagulates high dispersive polycarboxylic acid super-plasticizer at a low speed, the induction period in cement slurry hydration process is shorter, the main heat release of aquation
Peak appears earlier, this shows that solidifying high dispersive polycarboxylic acid super-plasticizer can effectively inhibit its slow setting to make at a low speed obtained by the present invention
With promoting the early stage hydration process of cement slurry.
The above embodiment is a preferred embodiment of the present invention, but embodiments of the present invention are not by above-described embodiment
Limitation, other any changes, modifications, substitutions, combinations, simplifications made without departing from the spirit and principles of the present invention,
It should be equivalent substitute mode, be included within the scope of the present invention.