(3) summary of the invention
One of technical problem that the present invention will solve provides a kind of new polycarboxylate water-reducer; It has high protect plasticity can, better steric hindrance effect is arranged, cement paste through the time loss little; Problems such as it is good to the control of cement plasticizing effect to overcome the prior art water reducer, and water-reducing rate is not high.
For solving the problems of the technologies described above, the present invention adopts following technical scheme:
A kind of polycarboxylate water-reducer, its molecular weight are 1000~100000, and structure is formed shown in (7):
In the formula (7), R
4Be selected from C
1~C
3Alkylidene group, R
5Be selected from hydrogen or C
1~C
3Alkyl, M are Na or K; A, b, c, d are integer, and wherein a is 1~80, and b is 0~300, and c is 0~80, and d is 1~200; When c=0, b=0; Wherein X represents polyether group, and the polyether group X in each structural unit independently is selected from shown in following formula (8-1), formula (8-3), the formula (8-3) a kind of in the group separately:
In formula (8-1), formula (8-2) or the formula (8-3), R
1Be selected from C
1~C
3Alkyl, R
2, R
3Independently be selected from C
1~C
3Alkylidene group, m, n, p, q are natural number, wherein the m value is 8~72, is preferably 18~56; The n value is 5~35; The p value is 1~71, and the q value is 1~71, and p+q=8~72, preferred p+q=18~56.
Further, the molecular weight of preferred described polyether group is 600~3000.
Need to prove that what formula (7) was represented is the structural unit composition of polycarboxylate water-reducer, does not represent the true ordering of structural unit.
The present invention to solve another technical problem provide a kind of preparation method of above-mentioned polycarboxylate water-reducer; It is under the prerequisite of guaranteeing the polymkeric substance water-reducing property; Esterification yield is high, synthesis technique is simple, easily-controlled reaction conditions, and can also reduce the production cost of polycarboxylate water-reducer.
For solving the problems of the technologies described above, the present invention adopts following technical scheme:
A kind of method for preparing described polycarboxylate water-reducer comprises the steps:
Steps A: in the presence of stopper and catalyzer, polyethers X-H and excessive unsaturated fatty acids carried out esterification 3~7 hours in 120~140 ℃, obtained carboxylate; Described unsaturated fatty acids is the unsaturated dibasic acid shown in the formula (2), perhaps is the mixing acid that the unsaturated monoprotic acid shown in unsaturated dibasic acid shown in the formula (2) and the formula (3) is formed; Described polyethers X-H is selected from a kind of or any several kinds combination in the compound shown in formula (1-1), formula (1-2), the formula (1-3);
In formula (1-1), formula (1-2) or the formula (1-3), R
1Be selected from C
1~C
3Alkyl, R
2, R
3Independently be selected from C
1~C
3Alkylidene group, m, n, p, q are natural number, wherein the m value is 8~72; The n value is 5~35; The p value is 1~71, and the q value is 1~71, and p+q=8~72;
In formula (2) or the formula (3), R
4Be C
1~C
3Alkylidene group, R
5Be hydrogen or C
1~C
3Alkyl;
Step B: in the aqueous solution, under action of evocating, carboxylate that steps A is made and remaining unsaturated fatty acids carried out copolymerization 2~5 hours in 55~100 ℃, made the carboxylic acid polyalcohol of formula (6);
In the formula (6), a, b, c, d are integer, and wherein a is 1~80, and b is 0~300, and c is 0~80, and d is 1~200; When c=0, b=0; R
4, R
5, X definition the same;
Step C: the carboxylic acid polyalcohol that step B is made neutralizes with alkaline solution, and control pH is 6~8, gets the polycarboxylate water-reducer product; Said alkaline solution is sodium hydroxide solution or potassium hydroxide solution.
Further, when the described unsaturated fatty acids of steps A was unsaturated dibasic acid, the present invention specifically recommended the mass ratio that feeds intake of polyethers and unsaturated dibasic acid to be: 65~96%: 35~4%, be preferably 70~90%: 30~10%.
Further; When the described unsaturated fatty acids of steps A was unsaturated dibasic acid and unsaturated monacid mixing acid, it was 55~96%: 35~1.5% that the present invention specifically recommends polyethers and unsaturated dibasic acid and the unsaturated monacid mass ratio that feeds intake: 33~1%.Preferably, described polyethers and unsaturated dibasic acid and the unsaturated monacid mass ratio that feeds intake are 65~95%: 30~3%: 30~2%.
Need to prove that the feed ratio of above-mentioned polyethers and unsaturated fatty acids is that the total mass in polyethers and unsaturated fatty acids is 100%.
The preferred 600-3000 of the molecular weight of polyethers according to the invention; Preferred following a kind of or any several kinds mixing: methoxy poly (ethylene glycol), oxyethyl group polyoxyethylene glycol, propoxy-polyoxyethylene glycol, structure suc as formula the compound shown in (9-2), structure suc as formula the compound shown in (9-3); In its Chinese style (9-2) or the formula (9-3), R
1Be selected from methyl, ethyl or propyl group.Said polyethers more preferably use methoxy poly (ethylene glycol), structure suc as formula the compound shown in (9-2), structure suc as formula a kind of or any several kinds mixing in the compound shown in (9-3), its Chinese style (9-2) or (9-3) in, R
1Be methyl.
The preferred methylene-succinic acid of unsaturated dibasic acid (methylene-succinic acid) shown in the described formula (2).
The preferred acrylic or methacrylic acid of unsaturated monoprotic acid shown in the described formula (3).
Catalyzer described in the concrete recommendation step A of the present invention is the vitriol oil or tosic acid, and the adding weight of described catalyzer is recommended as 0.5~5.0% of polyethers and unsaturated fatty acids gross weight, is preferably 0.5~3.5%.
Stopper described in the concrete recommendation step A of the present invention is one or both in thiodiphenylamine, the Resorcinol, and its consumption is recommended as 0.05~0.5% of unsaturated fatty acids gross weight, is preferably 0.1~0.5%.
Initiator described in the step B of the present invention can be selected from one or more in ammonium persulphate, Potassium Persulphate, Sodium Persulfate, SPC-D, Diisopropyl azodicarboxylate, the azo-bis-isobutyrate hydrochloride; Its add-on is recommended as 0.1~10% of polyethers and unsaturated fatty acids gross weight, is preferably 1~6%.
In the described copolymerization of step B, when the reaction system mass concentration was higher than 25%, for preventing crosslinking reaction, the present invention recommended to add chain-transfer agent, with the size of regulate polymer molecular weight.The add-on of chain-transfer agent is recommended as 0.2~1.5% of polyethers and unsaturated fatty acids gross weight; Said chain-transfer agent can be selected from one or more in thiohydracrylic acid, mercaptoethanol, n-butyl mercaptan, Virahol, 2 mercapto ethanol, 3-thiohydracrylic acid, the Thiovanic acid.If the reaction solution strength of solution is lower than 25%, then need not add chain-transfer agent.
Polymeric articles of the present invention can with existing carboxylic acid water reducing agent, the compound use of thionamic acid based water reducer, not only effectively concrete slump-loss is newly blocked in improvement, and improves dispersing property, increases water-reducing rate.In addition, the water reducer that the present invention makes can also with compound uses such as other air entrapment agents, retardant, hardening accelerator, skimmer, improve The comprehensive performance.
Poly carboxylic acid series water reducer of the present invention can be used as high performance concrete, the high slump keeps coagulating the important component of soil, high-flowing concrete, anticorrosion concrete; Be widely used in the concrete workses such as construction work, water conservancy, maritime works, bridge, tunnel remarkable economic efficiency and promotional value being arranged.
The present invention compared with prior art has advantage:
1. the present invention adopts unsaturated dibasic acid and polyethers to carry out esterification; In the macromole carboxylate that generates, both contained ester group, poly carboxylic acid macromole long-chain branch can be provided; The main steric hindrance that rises in the application; Contain carboxyl again, play in the application to protect and mould effect, the slump that can also improve polycarboxylate water-reducer keeps effect; And the unsaturated dibasic acid that the present invention adopted is cheap, contains two carboxyls, and this more helps carrying out esterification with polyethers, can reach higher esterification yield.
2. the present invention uses unsaturated monoprotic acid and unsaturated dibasic acid to synthesize jointly, on molecular structure, has considered to improve in the product molecule length of the density of carboxyl and adjustment side chain on the main chain, and the water-reducing rate of water reducer and protect plasticity can be improved greatly.
3. the chloride ion-containing not of the polycarboxylate water-reducer among the present invention, to the reinforcing bar non-corrosiveness, flexibility is strong, and applicable to the cement of plurality of specifications, model, standing storage is not stratified, do not have deposition.
4, use feeds nitrogen like the unsaturated dibasic acid of general formula (2) in the esterification of the present invention in the process, has not only protected reaction system but also played the effect of band water, has improved the esterification yield of product.
Polycarboxylate water-reducer of the present invention, it have protect plasticity height, cement paste through the time loss little, excellent properties such as water-reducing rate is higher, production cost is low.
(4) embodiment
Below the reference implementation example is described in more detail the present invention, the purpose of said embodiment only is to illustrate the present invention, and absolutely not the present invention is carried out any qualification.
Embodiment 1
Get the 150g molecular weight and be and put into the 500mL four-hole boiling flask after 1500 methoxy poly (ethylene glycol) melts, stir and add Resorcinol 0.12g, methylene-succinic acid 22.12g, 98% sulfuric acid 1.53g down, feed nitrogen and heat up, 125~128 ℃ of reactions 6 hours down; Being cooled to adding 89g water below 50 ℃ and 1.01g chain-transfer agent mercaptoethanol stirs as dropping liquid (1); Get 2.74g ammonium persulphate and 48g deionized water, wiring solution-forming is as dropping liquid (2); In the 500mL four-hole boiling flask, add the 89g deionized water, be warming up to 95 ℃, beginning drips above-mentioned dropping liquid (1) and (2) simultaneously; And under this temperature, at the uniform velocity drip and made it to add in 1.5 hours; Be incubated 1 hour down at 96~98 ℃, cooling, sodium hydroxide solution neutralization with 10%; Regulating the pH value is 7, finally makes polycarboxylate water-reducer of the present invention.
Embodiment 2
Get the 100g molecular weight and be and put into the 500mL four-hole boiling flask after 1000 methoxy poly (ethylene glycol) (0.1mol) melts; Stir and add Resorcinol 0.1g, thiodiphenylamine 0.04g, methylene-succinic acid 6.51g, vinylformic acid 23.06g, tosic acid 1.55g down; Feed nitrogen and intensification, reacted 5 hours down at 125~128 ℃; Being cooled to the 131.5g of adding below 50 ℃ water stirs as dropping liquid (3); Get 2.92g ammonium persulphate and 97g deionized water, wiring solution-forming is as dropping liquid (4); In the 1000mL four-hole boiling flask, add the 263g deionized water, be warming up to 65 ℃, beginning drips above-mentioned dropping liquid (3) and (4) simultaneously; And under this temperature, at the uniform velocity drip and made it to add in 3 hours; Be incubated 1 hour down at 68~70 ℃, cooling, sodium hydroxide solution neutralization with 10%; Regulating the pH value is 7, finally makes polycarboxylate water-reducer of the present invention.
Embodiment 3
Get the 120g molecular weight and be and put into the 500mL four-hole boiling flask after 1200 methoxy poly (ethylene glycol) melts; Stir and add Resorcinol 0.12g, methylene-succinic acid 13.2g, methylacrylic acid 34.5g, 98% sulfuric acid 1.22g down; Feed nitrogen and intensification, reacted 6 hours down at 122~125 ℃; Being cooled to the 165g of adding below 50 ℃ water stirs as dropping liquid (5); Get 7.4g ammonium persulphate and 124g deionized water, wiring solution-forming is as dropping liquid (6); In the 1000mL four-hole boiling flask, add the 332g deionized water, be warming up to 95 ℃, beginning drips above-mentioned dropping liquid (5) and (6) simultaneously; And under this temperature, at the uniform velocity drip and made it to add in 4 hours; Be incubated 1 hour down at 96~98 ℃, cooling, sodium hydroxide solution neutralization with 10%; Regulating the pH value is 7, finally makes polycarboxylate water-reducer of the present invention.
Comparing embodiment 4
Get the 155g molecular weight and be and put into the 500mL four-hole boiling flask after 1200 methoxy poly (ethylene glycol) melts, stir and add Resorcinol 0.21g, methylacrylic acid 42.61g, 98% sulfuric acid 1.53g down, feed nitrogen and heat up, 122~125 ℃ of reactions 6 hours down; Being cooled to adding 155g water below 50 ℃ and 1.55g chain-transfer agent mercaptoethanol stirs as dropping liquid (7); Get 5.83g ammonium persulphate and 94g deionized water, wiring solution-forming is as dropping liquid (8); In the 1000mL four-hole boiling flask, add the 355g deionized water, be warming up to 65 ℃, beginning drips above-mentioned dropping liquid (7) and (8) simultaneously; And under this temperature, at the uniform velocity drip and made it to add in 3 hours; Be incubated 1 hour down at 68~70 ℃, cooling, sodium hydroxide solution neutralization with 10%; Regulating the pH value is 7, the final polycarboxylate water-reducer that obtains routine.
Embodiment 5
By embodiment 1~4 prepared polycarboxylate water-reducer, the water reducer of gained is carried out flowing degree of net paste of cement and the test of mortar water-reducing rate according to GB/T8077-2000.Test cement is local conch 42.5R, wc 0.29, and the water reducer volume is gives money as a gift 0.25%, measuring result such as table 1:
Table 1
Above data show that independent methylene-succinic acid and the polyethers of using carries out esterification among the embodiment 1, and the protect plasticity of its product can be relatively good, protect to mould to change in time in the test to lose from clean slurry to be negative value; Use among the embodiment 2 that vinylformic acid and methylene-succinic acid are common to carry out esterification with polyethers, the initial clean slurry dispersiveness of its product is better, but loses relatively large; Use among the embodiment 3 methylacrylic acid and methylene-succinic acid jointly and polyethers carry out esterification, it is very little that its product is starched loss only, water-reducing rate is also higher; Be the preparation method who generally acknowledges at present in the comparing embodiment 4, the clean slurry retentivity of its product is poor, and water-reducing rate is also relatively low simultaneously.