CN101050083A - Method for preparing water reducing agent in series of polyocarboxy acid for concrete - Google Patents

Abstract

This invention discloses a method for preparing poly (carboxylic acid) water reducer for concrete. The method comprises: preparing the raw materials, pre-heating the base materials, and reacting to obtain the product. The poly (carboxylic acid) water reducer is prepared by free radical polymerization with water as the solvent. The method is simple, and does not need any organic solvent, thus is clean. The product has such advantages as high performance, low doping amount, high water reduction efficiency, low collapse loss, high compatibility with cement, no pollution and low cement consumption, and can increase the doping amounts of fly ashes and slag. The product can be used in high-strength concrete, self-leveling concrete, pumpable concrete and injected concrete that need high workability, high strength and high durability.

Description

A kind of preparation method of water reducing agent in series of polyocarboxy acid for concrete

[technical field]

The present invention relates to a kind of preparation method of cement water reducing agent, particularly be the preparation method of water reducing agent in series of polyocarboxy acid for concrete.

[background technology]

The modern construction requires to improve constantly to concrete various use propertieies, the particularly development of high performance concrete, green concrete, energy-conservation concrete proposition and technology thereof, promoted the development of concrete admixture technology, thereby the research potential of the energy-saving building materials that the GHPC that makes low cement content is used is huge, has a extensive future.

High performance water reducing agent of polyocarboxy acid is a latest generation environmental type concrete admixture in the world, have that volume is low, water-reducing rate is high, slump-loss is few, good with cement adaptability, can improve flyash and fine slag contents, pollution-free, save advantage such as cement, can be widely used in the field that high-strength concrete, self-leveling concrete, pump concrete, sprayed concrete etc. have higher requirements to workability of concrete, intensity, weather resistance, its appearance is paid close attention to widely and is studied.

CN00127294.2 has introduced a kind of carboxylic-acid graft type high-performance water reducing agent and synthetic method thereof, its processing method is as follows: having thermometer, agitator, in the 500ml four-necked bottle of dropping funnel and reflux condensing tube, with the unsaturated vinyl monomer that contains side group is comonomer, with the Ammonium Persulfate 98.5 is initiator, gets 90 ℃ of following copolymerization.The shortcoming that this method exists is: do comonomer with unsaturated vinyl monomer, can play the dispersing property that improves water reducer to a certain extent, the slump through the time loss bigger, in addition because the complicacy of multi-component copolymer, the controllability of its molecular designing is also poor.

CN99127479.2 has introduced polycarboxylic acid polymer that is used as cement additire of Japanese catalyst invention and preparation method thereof, this method is: add maleic anhydride, ethyl vinyl ether and methylethylketone (tetrahydrofuran (THF)) in the glass reactor that thermometer, agitator, nitrogen inlet tube and reflux condensing tube are housed, be warming up to 70 ℃, add Diisopropyl azodicarboxylate simultaneously, reacted 6 hours, after reaction finishes, boil off methylethylketone (tetrahydrofuran (THF)).Obtain ethyl vinyl ether-copolymer-maleic anhydride.What this method adopted is that organic solvent is a reaction carriers, though it will distill away at last, but with present copolymerization technique, solvent is difficult to accomplish to go out fully, so this method is unfavorable for cleaner production, and it is binary copolymerization, contains poly carboxylic acid group and ethers monomer in the product, can strengthen water-reducing effect and but be difficult to the control slump-loss, be of limited application.

CN00103594.0 has introduced a kind of preparation method of polycarboxylate high performance water-reducing agent, concrete processing method is as follows: the first step, with the methyl Soxylat A 25-7, Resorcinol, tosic acid is put into reactor, under 85 ± 3 ℃ temperature, after stirring is dissolved Resorcinol fully, in solvent, drip methyl methacrylate, in 15 ± 5 minutes, drip off, be incubated 8 ± 0.5h then.Second step was a solvent with the butanone, and dibenzoyl peroxide is an initiator, makes the product and the methacrylic acid polymerization reaction take place of the first step.The shortcoming that this method exists is the reaction process more complicated, and owing to technical reason, the product of its first step is impure more, influences next step copolyreaction, and a large amount of organic solvents that are unfavorable for environment protection that use in its production process, is unfavorable for cleaner production.

CN94194183.3 is modified cement additive product with change rheological of U.S. W. R. Grace ﹠ Co application and preparation method thereof, its concrete grammar is: it is primary amine groups that solid propenoic acid is joined an end, one end is in the polyethylene-poly(propylene oxide) polymkeric substance of methyl, stir earlier 30min at normal temperatures, then under 180 ℃, reaction mixture is in the flowing nitrogen layer 1 hour 10 minutes, in nitrogen gas stream, remove the by product that anhydrates, obtain product.Its shortcoming and CN99127479.2 are similar, adopt vinylformic acid and polyethylene-poly(propylene oxide) binary copolymerization, its product is better to concrete dispersion effect, but control concrete slump loss effect is limited, limited its range of application greatly, and the cost of material that should react used is quite expensive, is unfavorable for the large-scale promotion utilization.

CN03157443.2 has introduced a kind of preparation method of the high performance concrete water reducer with the co-poly carboxylic acid class.Having mechanical stirrer, thermometer, dropping funnel, add entry in 1000 milliliters of glass reactors of prolong, be heated to 80 ℃, adding afterwards contains polyalkylene glycol mono ester monomer, unsaturated carboxylic acid, unsaturated diacid, allyl sulphonic acid and some linking agent copolymerization of long-chain oxyalkylene collection group and gets.This method products obtained therefrom has dispersedly fine, certain slump hold facility is also arranged, but its concrete intensity is lower, is difficult for high-strength, the durable concrete of configuration, and its processing condition are also complicated.

The preparation method of comprehensive above polycarboxylate water-reducer, the technology of the production polycarboxylate water-reducer that has are too complicated, and condition is relatively harsher, is unfavorable for large-scale industrial production; The effect of the water reducer of the preparation that has is not fine; The controllability of the polymerization process reaction that has is poor; The method that has has also been used the organic solvent of contaminate environment except the technology more complicated, is unfavorable for protecting environment and cleaner production; The cost that has is too high.

[summary of the invention]

The objective of the invention is to overcome that water reducer complex manufacturing, water-reducing rate were not high in the past, cost is high, the slump through the time loss big, with inferior suitability, the big monomer technology of preparing of polyoxy alkane thiazolinyl allyl ester is weak and the organic solvent contaminate environment of wherein carrying and be unfavorable for shortcoming such as cleaner production, and a kind of water reducing agent in series of polyocarboxy acid for concrete preparation method of high-performance environment-friendly is provided.

A kind of concrete polycarboxylate water-reducer preparation method comprises the steps:

1) preparation work: in the four-hole boiling flask that thermometer, agitator, dropping funnel, reflux condensing tube, rare gas element ingress pipe are housed, earlier with the air in the inert gas replacement bottle;

2) bed material preheating: in four-hole boiling flask, add allyl sulphonic acid salt monomer and water as bed material, heating in water bath to 55～80 ℃;

3) reaction process: in flask, drip and prepare certain density polyoxy alkane alkene unsaturated acid ester monomer solution, unsaturated acid and/or derivatives monomer solution in advance, monomer mixed solution is added drop-wise to the reaction flask with initiator solution from different dropping funnels simultaneously, after in 1～2h, dripping off, add a little amine-thiol chain transfer agents or do not add, be warming up to 80 ℃～90 ℃ then, continue insulation 3～6 hours;

4) finished product: reaction finishes the back and regulates product P H value between 6～9 with dilute alkaline soln, obtains finished product.

Free radical polymerisation process is adopted in the preparation of polycarboxylate water-reducer of the present invention, is solvent with water, and polymerization process is not used any organic solvent, and technology is simple and easy to control, and no three industrial wastes are really accomplished cleaner production; Product performance are good, have that volume is low, water-reducing rate is high, slump-loss is few, good with cement adaptability, can improve flyash and fine slag contents, pollution-free, save advantage such as cement, can be widely used in the field that high-strength concrete, self-leveling concrete, pump concrete, sprayed concrete etc. have higher requirements to workability of concrete, intensity, weather resistance.

[embodiment]

The polymerization process that the present invention adopts is the free radical multi-component copolymer mechanism that the personage knows in the industry, select initiator efficiently for use, by control, obtain a fixed structure and poly carboxylic acid multiple copolymer that molecular weight distribution is narrower to initiator add-on, temperature, monomer ratio.

Used unit serving is a weight part among the embodiment.

Embodiment 1:

In the 250ml four-hole boiling flask that thermometer, agitator, dropping funnel, reflux condensing tube, rare gas element ingress pipe are housed, earlier with the air in the inert gas replacement bottle; Add 5 parts methylpropene sodium sulfonate and 20 parts of water more inwards as bed material, heating in water bath to 55 ℃～80 ℃; Take by weighing 20 parts of vinylformic acid and 75 parts of polyethyleneglycol acrylate mixing respectively, add 160 parts of water again and be made into dilute solution, take by weighing 3.6 parts of ammonium persulphates and 1.2 parts of sodium bisulfites, add 68 parts of water and be made into dilute solution, the monomer mixed solution that configures is added drop-wise to the reaction flask from different dropping funnels simultaneously with initiator solution, and control is dripped speed and is dripped off in 1～2h, adds a spot of chain-transfer agent then, temperature is increased to 80 ℃～90 ℃, continues insulation 4～6h; Regulate PH=6～9 with dilute alkaline soln, both obtained product of the present invention, product is a light yellow transparent solution.

Embodiment 2:

In the 250ml four-hole bottle that thermometer, agitator, dropping funnel, reflux condensing tube, rare gas element ingress pipe are housed, earlier with the air in the inert gas replacement bottle; In bottle, add 35 parts of methylpropene sodium sulfonates and 81 parts of water again and do bed material, heating in water bath to 55 ℃～80 ℃; Take by weighing 30 parts of vinylformic acid and 60 parts of polyoxyethylene acrylate respectively and mix, add 210 parts of water again and be made into dilute solution, following step, reaction conditions are identical with embodiment 1, and product is a light yellow transparent liquid.

Embodiment 3:

In the 250ml four-hole bottle that thermometer, agitator, dropping funnel, reflux condensing tube, rare gas element ingress pipe are housed, earlier with the air in the inert gas replacement bottle; In bottle, add 20 parts of methylpropene sodium sulfonates and 45 parts of water and do bed material, heating in water bath to 55 ℃～80 ℃; Take by weighing 35 parts of polyoxyethylene glycol mono acrylic esters and 10 parts of vinylformic acid again and mix, add 163 parts of water and be made into dilute solution, following step, reaction conditions are identical with embodiment 1, and product is a light yellow transparent liquid.

Embodiment 4:

In the 250ml four-hole bottle that thermometer, agitator, dropping funnel, reflux condensing tube, rare gas element ingress pipe are housed, earlier with the air in the inert gas replacement bottle; Methylpropene sodium sulfonate and 36 parts of water of adding 15 parts are more inwards done bed material, heating in water bath to 55～65 ℃; Take by weighing 18 parts of gram maleic anhydrides, 22 parts of acrylic or methacrylic acid, 25 parts of polyethylene glycol methacrylate-styrene polymers mixing, add 165 parts of water and be made into dilute solution, take by weighing 4.1 parts of Potassium Persulphates and 1.8 parts of sodium bisulfites are made initiator, add 54 parts of water and be made into dilute solution, be added drop-wise to the reaction flask with initiator solution simultaneously from different dropping funnels the monomer mixed solution that configures, the dropping time is controlled at 1～2h and drips off, and is warming up to 80 ℃～90 ℃ after dropwising, and continues insulation 3～5h; Reaction finishes, and regulates pH value between 6～9 with dilute alkaline soln, obtains product of the present invention, and product is a light yellow transparent liquid.

Embodiment 5:

In the 250ml four-hole bottle that thermometer, agitator, dropping funnel, reflux condensing tube, rare gas element ingress pipe are housed, earlier with the air in the inert gas replacement bottle; Take by weighing 26 parts of methylpropene sodium sulfonates and 62 parts of water are done bed material, heating in water bath to 55～65 ℃; Take by weighing 25 parts of butyl methacrylate and 15 parts of methoxy polyoxyethylene methacrylic esters mixing, add 105 parts of water and be made into alkene solution, take by weighing 2.1 parts of ammonium persulphates and 0.9 part of S-WAT is made initiator, add 27 parts of water and be made into dilute solution, following step, reaction conditions are identical with embodiment 4, and product is a light yellow transparent liquid.

Embodiment 6:

In the 250ml four-hole bottle that thermometer, agitator, dropping funnel, reflux condensing tube, rare gas element ingress pipe are housed, earlier with the air in the inert gas replacement bottle; Take by weighing 10 parts of sodium allylsulfonates and 28 parts of water are done bed material, heating in water bath to 55～65 ℃; Taking by weighing 11 parts of vinylformic acid, 16 parts of methyl methacrylates, 18 parts of methoxy polyoxyethylene methacrylic esters and 12 parts of polyethylene glycol acrylate mixes, add 210 parts of water and be made into dilute solution, take by weighing 2.1 parts of ammonium persulphates and 0.9 part of sodium bisulfite is made initiator, add 27 parts of water and be made into dilute solution, following step, reaction conditions are identical with embodiment 4, and product is a light yellow transparent liquid.

The The performance test results of product:

Slump test

The water reducer kind	Volume (%)	The initial slump (mm)	The slump behind the 60min (mm)	The 90min slump (mm)	The slump behind the 120min (mm)
						Embodiment 1	0.2	185	190	185	100
Embodiment 2	0.2	190	190	195	130
						Embodiment 3	0.2	180	195	180	150
Embodiment 4	0.2	195	190	190	155
						Embodiment 5	0.2	180	195	190	140
Embodiment 6	0.2	175	170	170	145

Annotate: volume accounts for the percentage ratio of cement quality for the water reducer solid content.

The mensuration of water-reducing rate

The product code name	Embodiment 1	Embodiment 2	Embodiment 3	Embodiment 4	Embodiment 5	Embodiment 6
							Water-reducing rate	30％	32％	31％	31.5％	30.5％	29％

Compressive strength rate

The experiment code name	Embodiment 1	Embodiment 2	Embodiment 3	Embodiment 4	Embodiment 5	Embodiment 6
							The 3d compressive strength rate, %	151.3	154.7	144.8	153.6	151.7	147.2
The 7d compressive strength rate, %	139.7	151.2	140.5	134.8	149.6	132.7
							The 28d compressive strength rate, %	120	134.6	123.3	117.4	128.6	122

Annotate: GB/T 8077-2000 is adopted in above test.

Polycarboxylate water-reducer preparation method of the present invention is radical polymerization, its technology is simple, reaction conditions is easy to control, and reaction is a carrier with water, the organic solvent that does not contain contaminate environment, be beneficial to cleaner production, the present invention can effectively control the slump in the common high performance water reducing agent of polyocarboxy acid use through the time loss big phenomenon, can reduce the concrete hydrating thermal peak.The basic free of losses of the slump in its 28 days compressive strength rate 〉=160%, 90 minute.The incorporation of this water reducer accounts for 0.2%～0.5% of cement quality for the water reducer solid content, and water-reducing rate can reach 30%, not bleed.

Claims (1)

1, a kind of concrete polycarboxylate water-reducer preparation method comprises the steps:

1) preparation work: in the four-hole boiling flask that thermometer, agitator, dropping funnel, reflux condensing tube, rare gas element ingress pipe are housed, earlier with the air in the inert gas replacement bottle;

2) bed material preheating: in four-hole boiling flask, add allyl sulphonic acid salt monomer and water as bed material, heating in water bath to 55～80 ℃;

3) reaction process: in flask, drip and prepare certain density polyoxy alkane alkene unsaturated acid ester monomer solution, unsaturated acid and/or derivatives monomer solution in advance, monomer mixed solution is added drop-wise to the reaction flask with initiator solution from different dropping funnels simultaneously, after in 1～2h, dripping off, add a little amine-thiol chain transfer agents or do not add, be warming up to 80 ℃～90 ℃ then, continue insulation 3～6 hours;

4) finished product: reaction finishes the back and regulates product P H value between 6～9 with dilute alkaline soln, obtains finished product.