CN113801330B

CN113801330B - Preparation method of block-type organic silicon polycondensate mud-resistant high-efficiency water reducer

Info

Publication number: CN113801330B
Application number: CN202110959630.1A
Authority: CN
Inventors: 赵晖; 陈达; 廖迎娣; 欧阳峰; 徐海生
Original assignee: Jinling Institute of Technology
Current assignee: Jinling Institute of Technology
Priority date: 2021-08-20
Filing date: 2021-08-20
Publication date: 2023-01-31
Anticipated expiration: 2041-08-20
Also published as: CN113801330A

Abstract

The invention discloses a preparation method of a block-type organosilicon polycondensate anti-mud type high-efficiency water reducing agent, which comprises the steps of carrying out addition reaction on active hydrogen on a polydimethylsiloxane oligomer and vinyl oxirane double bonds, carrying out ring-opening reaction on sodium sulfamate and an epoxy group in the block-type polydimethylsiloxane oligomer, introducing sulfonic groups and amino groups onto the block-type polydimethylsiloxane oligomer, and carrying out high-temperature dehydration and polycondensation to obtain a block-type polydimethylsiloxane oligomer containing-SO ₃ a-NH group block type organosilicon polycondensate mud-resistant high-efficiency water reducing agent. The preparation method increases the number and molecular weight of organosilane groups in the molecule of the block-type organosilicon polycondensate high-efficiency water reducing agent, and improves the adsorption and dispersion capacity, dispersion stability and mud resistance of the mud-resistant high-efficiency water reducing agent on the surface of cement particles. The anti-mud high-efficiency water reducing agent prepared by the high-temperature dehydration polycondensation method has good homogeneity and retarding performance, simplifies the production process, and has good long-term storage stability. Is a preparation method of the anti-mud high-efficiency water reducing agent with wide application prospect.

Description

Preparation method of block-type organic silicon polycondensate mud-resistant high-efficiency water reducer

Technical Field

The invention belongs to preparation of concrete chemical additives, and particularly relates to a preparation method of a block-type organic silicon polycondensate mud-resistant high-efficiency water reducing agent containing sulfonic groups and amino groups.

Background

The polycarboxylic acid type high-efficiency water reducing agent has better dispersion performance than the traditional water reducing agent, can obviously improve the initial fluidity and the flow retentivity of concrete and improve the mechanical strength of the concrete, and is widely used in large-scale building engineering. But the polycarboxylate superplasticizer has strong sensitivity to clay carried in aggregates, the components of the aggregates carrying the clay are mainly clay minerals such as kaolinite, illite, montmorillonite and the like, and the clay minerals are of silicon-oxygen tetrahedron and aluminum-oxygen octahedron layered structures. The polycarboxylic acid high-efficiency water reducing agent molecules are easily intercalated and adsorbed into a layered structure of clay minerals, so that the adsorption capacity and the adsorption rate of the polycarboxylic acid high-efficiency water reducing agent molecules to soil are far larger than those of cement particles, the adsorption of the polycarboxylic acid high-efficiency water reducing agent on the cement particles is reduced, the water reducing effect of the polycarboxylic acid high-efficiency water reducing agent is reduced, the slump loss rate of concrete is increased, and the high-mud-content aggregate can weaken the strength of a transition area between cement and an aggregate interface, so that the long-term physical mechanical property and the volume stability of the concrete are reduced.

In order to solve the negative influence of the excessive mud content of the aggregate on the polycarboxylic acid high-efficiency water reducing agent, related researchers use silane monomers containing carbon-carbon double bonds to carry out free radical copolymerization reaction with sodium methallyl sulfonate, methoxy polyethylene glycol acrylate and allyl polyethylene glycol monomers for preparing the polycarboxylic acid high-efficiency water reducing agent. Introducing siloxane groups into the hydrophobic chain segment of the polycarboxylic acid high-efficiency water reducing agent to prepare the silane modified polycarboxylic acid high-efficiency water reducing agent. The silane modified polycarboxylic acid high-efficiency water reducing agent generates silicon hydroxyl chemical bonding on the surface of cement particles under the strong alkaline condition, and the chemical bonding strength is higher than the electrostatic adsorption of the polycarboxylic acid high-efficiency water reducing agent. The organic silicon modified polycarboxylate superplasticizer can increase adsorption and adsorption driving forces of water reducer molecules on the surfaces of cement particles, and improve the dispersing capacity of the polycarboxylate superplasticizer to cement.

However, silane monomers are available in limited sources and are expensive. Meanwhile, the silane reaction monomer containing unsaturated double bonds has low solubility in water and high surface activation energy, the proportion of organosilane groups in the molecules of the prepared silane-modified polycarboxylic acid high-efficiency water reducing agent is small, the molecular weight of the silane-modified polycarboxylic acid high-efficiency water reducing agent is not high, and the dispersing effect of cement particles is difficult to obviously improve. In addition, in the prior art, the organosilicon compound is easy to carry out copolymerization reaction with unsaturated carboxylic acid compounds with high reactivity ratio and is difficult to react with linear polymers with copolymerization reaction activity, and the prepared organosilicon modified polycarboxylic acid high-efficiency water reducing agent has poor uniformity and unsatisfactory retardation performance. Finally, the existing organosilicon modified polycarboxylic acid high-efficiency water reducing agent has a complex production process, and the difficulty and uncertainty of a free radical reaction process are increased due to the use of a chain initiator. These problems have hindered the use of silicon-based modified polycarboxylic acid superplasticizers in the modern concrete industry. Therefore, the development of a silicon-based modified high-efficiency water reducing agent which has the advantages of simple preparation process, good mud resistance effect, retarding property and environmental protection becomes a research hotspot at present.

Disclosure of Invention

The invention aims to: the invention aims to provide a preparation method of a block-type organosilicon polycondensate high-efficiency water reducing agent containing sulfonic groups and amino groups, which increases the number and molecular weight of organosilane groups in the molecules of the block-type organosilicon polycondensate high-efficiency water reducing agent, improves the adsorption, dispersion capacity, dispersion stability and mud resistance of the mud-resistant high-efficiency water reducing agent on the surfaces of cement particles, improves the uniformity and the retardation of the mud-resistant high-efficiency water reducing agent, simplifies the production process and simplifies the long-term storage stability of products.

The technical scheme is as follows: the invention relates to a preparation method of a block-type organic silicon polycondensate mud-resistant high-efficiency water reducing agent, which comprises the following steps of:

(1) Mixing vinyl ethylene oxide with an absolute ethanol solution, adding a dimethyl-terminated polydimethylsiloxane oligomer, slowly dropwise adding a diethyl zinc solution, and reacting after dropwise adding is finished to obtain a block-type polydimethylsiloxane oligomer with epoxy groups connected at two ends;

(2) Mixing and stirring the block-type polydimethylsiloxane oligomer with epoxy groups connected at two ends, sodium sulfamate and water to form a uniform and clear solution, adjusting the pH value of the solution to 9-10, and carrying out ring opening reaction to obtain the block-type polydimethylsiloxane oligomer with hydroxyl, amino and sulfonic groups connected at two ends;

(3) Rapidly stirring a block-type polydimethylsiloxane oligomer solution with hydroxyl, amino and sulfonic groups connected at two ends, adjusting the pH of the solution to be 14-15, and performing intermolecular dehydration polycondensation to prepare a block-type polydimethylsiloxane polymer with sulfonic groups and amino groups at two ends;

(4) And in the later reaction stage, adjusting the pH value of the system to 10-11, and cooling and curing to obtain the block-type organic silicon polycondensate anti-mud high-efficiency water reducing agent containing sulfonic groups and amino groups.

Further, the later stage of the reaction in the step (4) is specifically after the intermolecular dehydrating polycondensation reaction in the step (3) is carried out for 5 to 6 hours.

Further, in the step (1), the mass ratio of the vinyl oxirane, the absolute ethanol solution, the double-hydrogen-terminated polydimethylsiloxane oligomer and the diethyl zinc solution is 9.8-10: 15 to 16:326 to 330:1.51 to 1.52; wherein, the purity of the diethyl zinc solution is 99.5-99.8%.

Further, in the step (1), when the diethyl zinc solution is dripped, the system temperature is kept at 40-50 ℃, and the dripping time is 45-60 min.

Further, in the step (1), the reaction temperature after dripping the diethyl zinc catalyst solution is 60-65 ℃, and the reaction time is 8-10 h.

Further, in the step (2), the mass ratio of the block-type polydimethylsiloxane oligomer with epoxy groups connected at two ends to the sodium sulfamate is 336-340: 13.4 to 13.5.

Further, in the step (2), the ring-opening reaction temperature is 75-80 ℃, and the reaction time is 6-7 h.

Further, in the step (3), the reaction temperature of intermolecular high-temperature dehydration polycondensation is 90-95 ℃, and the reaction time is 5-6 hours.

Further, in the step (4), the cooling curing time is 2-3 h, and the cooling temperature is 20-25 ℃.

Further, in the step (2), the step (3) and the step (4), the pH is adjusted by using a sodium hydroxide solution, and the mass fraction concentration of the sodium hydroxide solution is 20%.

Further, in the step (4), the weight average molecular weight of the organosilicon polycondensate anti-mud high efficiency water reducing agent is 26456-27139, the pH value is 11-12, and the solid content is 23-30%.

Aiming at the problems that in the existing process of preparing the silicon-based modified polycarboxylic acid high-efficiency water reducing agent, unsaturated double-bond silane has poor water solubility and low copolymerization reaction activity; the prepared silane modified polycarboxylic acid high-efficiency water reducing agent has small proportion of organosilane groups in molecules, small molecular weight and poor uniformity; the production process of the organic silicon modified polycarboxylic acid high-efficiency water reducing agent is complex, and highly toxic waste gas harmful to the surrounding environment and the health is easily generated in the production process; the silicon-based modified polycarboxylic acid high-efficiency water reducing agent has the problems of reducing the dispersion effect of cement particles and the like. The invention starts from the molecular design principle of the anti-mud high-efficiency water reducing agent and the reaction characteristic of the silane compound, abandons the way that the prior silane compound mainly modifies the polycarboxylic acid high-efficiency water reducing agent through free radical polymerization, uses silane oligomer with good water solubility as a reaction monomer, and utilizes the characteristic that active end-capped hydrogen on the polydimethylsiloxane oligomer molecule and double bonds in ethylene oxide with unsaturated bonds are easy to carry out addition reaction. Meanwhile, hydroxyl, amino and sulfonic group are introduced into the block-type organic silicon compound by means of ring-opening reaction between the sulfonated amino monomer and epoxy group on the block-type organic silicon oligomer. Under the condition of high temperature, the hydroxyl groups on the block-type organic silicon oligomer containing sulfonic acid groups and amino groups are subjected to intermolecular dehydration and polycondensation reaction to prepare the straight-chain organosilane modified polycondensate anti-mud type high-efficiency water reducing agent containing C-Si bonds.

The preparation process and principle of the invention are as follows: the invention uses water-soluble double-hydrogen-group-terminated polydimethylsiloxane oligomer, vinyl oxirane and sodium sulfamate as reaction monomers. Firstly, under the action of a catalyst, si-H bonds in the dihydro-terminated polydimethylsiloxane oligomer and carbon-carbon double bonds in vinyl oxirane generate hydrosilylation reaction to obtain a block-type polydimethylsiloxane oligomer with epoxy groups connected at two ends. Then, under the alkaline condition, the sodium sulfamate and epoxy groups in the block-type polydimethylsiloxane oligomer carry out ring-opening reaction to obtain a product with-OH and NHSO ₃ Blocked polydimethylsiloxane oligomer of Na. At high temperature, containing-OH, -NHSO ₃ Na block type polydimethylsiloxane oligomer is subjected to intermolecular polycondensation dehydration to prepare the product containing-SO ₃ A block-type organosilicon polycondensate mud-resistant high-efficiency water reducing agent of-NH groups. The dihydrogen-terminated polydimethylsiloxane oligomer is used for replacing a reaction monomer of a silane coupling agent containing carbon-carbon double bonds and a silane compound for preparing the organic silicon modified polycarboxylic acid high-efficiency water reducing agent, so that the source of raw materials for preparing the anti-mud high-efficiency water reducing agent is widened. According to the method for preparing the anti-mud type high-efficiency water reducing agent, the water-soluble dihydro-terminated polydimethylsiloxane oligomer is used as a reaction monomer, sulfonic groups and amino groups are introduced to the block-type organic silicon polycondensate anti-mud type high-efficiency water reducing agent with high organic silane content, and the molecular weight of the organic silane modified polycondensate anti-mud type high-efficiency water reducing agent is effectively increased. The block-type organosilicon modified polycondensate anti-mud high-efficiency water reducing agent is added into cement slurry, so that the interface energy of a liquid-solid interface in a cement system is reduced, siloxane groups on molecular side chains of the block-type organosilicon polycondensate are chemically bonded on the surfaces of cement particles, the dispersing capacity of the block-type organosilicon polycondensate high-efficiency water reducing agent on the cement particles is improved, and the dispersing stability of the high-efficiency water reducing agent on the cement particles is improved by amino groups connected on the modified organosilane polycondensate. The high-molecular polymer anti-mud high-efficiency water reducing agent is obtained by high-temperature dehydration and polycondensation, the steps of chain initiation, phase transfer and the like in the reaction of preparing the organic silicon modified polycarboxylic acid high-efficiency water reducing agent by free radical polymerization are avoided, and the prepared block-type organic silicon polycondensate anti-mud high-efficiency water reducing agent with sulfonic groups and amino groups has the characteristics of good uniformity and good slow setting performance.

Has the beneficial effects that: compared with the prior art, the invention has the following remarkable advantages:

(1) According to the invention, silicon base and sulfonic group are introduced into the molecular chain of the block-type organosilicon condensation polymer superplasticizer, so that the interfacial energy of the block-type organosilicon condensation polymer superplasticizer at a liquid-solid interface in a cement system is reduced, and the adsorption, adsorption driving force and electrostatic repulsion of the block-type organosilicon condensation polymer superplasticizer on the surface of cement particles are increased. Siloxane groups on the side chains of the block-type organosilicon polycondensates generate chemical bonding on the surfaces of cement particles, so that the dispersing capacity of the block-type organosilicon polycondensate high-efficiency water reducing agent to the cement particles is improved. The modified organosilane polycondensate is connected with amino groups, so that the dispersion stability of the organosilane polycondensate type high-efficiency water reducing agent on cement particles can be obviously improved. Under the condition of keeping the initial fluidity of the concrete unchanged, only one item of the use cost of the raw materials of the high-efficiency water reducing agent is reduced and the cost for compounding the anti-mud sacrificial agent is saved, and the saved cost of each formula of concrete reaches 5.12 yuan.

(2) The block-type organosilane-modified polycondensate anti-mud high-efficiency water reducing agent prepared by the method can effectively improve the number and the molecular weight of hydrophilic organosilane groups in the molecules of the organosilane-modified polycondensate anti-mud high-efficiency water reducing agent.

(3) The block-type organic silicon modified polycondensate mud-resistant high-efficiency water reducing agent prepared by the invention uses a dihydro-terminated polydimethylsiloxane oligomer, vinyl ethylene oxide, sodium sulfamate and a small amount of diethyl zinc catalyst as raw materials. The raw materials are wide and low in price, and the cost of the raw materials can be saved by 203 yuan for producing one ton of the block type organic silicon modified polycondensate anti-mud high efficiency water reducing agent. The method for preparing the anti-mud high-efficiency water reducing agent expands the raw material source of the high-efficiency water reducing agent.

(4) The invention uses the monomer addition, ring-opening reaction and high-temperature dehydration polycondensation method to prepare the block-type organosilicon modified polycondensate anti-mud high-efficiency water reducing agent containing sulfonic groups and amino groups, avoids the steps of chain initiation, phase transfer, polymerization and chain termination of free radical polymerization in the preparation of the traditional organosilicon modified polycarboxylic acid high-efficiency water reducing agent, simplifies the preparation process, shortens the production time and improves the production efficiency. The production cost can be reduced by 35.2 yuan for producing one ton of the block type organosilicon modified polycondensate mud-resistant high-efficiency water reducing agent. The discharge of highly toxic waste gas in the production process is reduced, the negative effects of the production process of the high-efficiency water reducing agent on the environment and public health are avoided, and the green production of the high-efficiency water reducing agent is realized.

(5) The water-soluble dihydro-terminated polydimethylsiloxane oligomer is used as a raw material to produce the block-type organosilicon condensation polymerization type anti-mud superplasticizer, and the prepared block-type organosilicon condensation polymer anti-mud superplasticizer with sulfonic groups and amino groups has good uniformity and water resistance and good retardation performance. The long-term storage stability of the block-type organosilicon polycondensate anti-mud high-efficiency water reducing agent product is ensured.

(6) 3000 tons of block type organosilicon polycondensate anti-mud high-efficiency water reducing agent is produced every year, the environmental benefit generated by reducing the exhaust emission is not included, and only the raw material and the production cost can save 60.9 ten thousand yuan. Saving production equipment, investment cost, simplifying flow and reducing production time can generate 10.56 ten thousand yuan of economic benefit. 3000 tons of the mud-resistant high-efficiency water reducing agent can be used for preparing 6.67 multiplied by 10 ⁶ The cost of the high-efficiency water reducing agent material can be saved by 341.33 ten thousand yuan based on square concrete. 3000 tons of the block type organosilicon polycondensate mud-resistant high-efficiency water reducing agent are produced every year, and the economic benefit of 412.79 ten thousand yuan can be generated.

Drawings

FIG. 1 is a preparation process of a block-type organosilicon polycondensate mud-resistant high-efficiency water reducer;

FIG. 2 is a comparison of the surface tension of HPVSSP and Si-PCE SP at different concentrations;

FIG. 3 is a comparison of water reduction rates of HPVSS SP and Si-PCE SP doped at different doping amounts;

FIG. 4 shows the initial setting time of concrete doped with HPVSS SP and Si-PCE SP at different doping amounts;

FIG. 5 shows the final setting time of concrete doped with HPVSS SP and Si-PCE SP at different doping amounts;

FIG. 6 shows compressive strength of concrete doped with HPVSS SP at different doping levels;

FIG. 7 shows the compressive strength of concrete doped with Si-PCE SP at different doping levels;

FIG. 8 shows slump of concrete doped with HPVSS SP as a function of time for different mud loadings;

FIG. 9 shows the concrete slump with Si-PCE SP added under different mud content changes with time;

FIG. 10 shows that the compressive strength of concrete doped with HPVSS SP varies with the curing age under different mud contents;

FIG. 11 shows that the compressive strength of the concrete doped with Si-PCE SP varies with the curing age under different mud contents;

FIG. 12 shows that the flexural strength of concrete doped with HPVSS SP varies with the age of curing under different mud contents;

FIG. 13 shows that the flexural strength of the concrete doped with Si-PCE SP varies with the age of curing under different mud contents.

Detailed Description

The technical solution of the present invention is further described in detail with reference to the drawings and the embodiments.

The experimental methods described in this example are all conventional methods unless otherwise specified; the reagents and materials are commercially available, unless otherwise specified. The specific preparation process is shown in figure 1.

Wherein the dihydro-terminated polydimethylsiloxane oligomer (industrial grade, viscosity of 500-1500mPa & s, weight-average molecular weight of 4600-4800) is produced by Qingdao Deming chemical Co., ltd; vinyl ethylene oxide (technical grade, 99% purity) was purchased from sigma aldrich trade, ltd; absolute ethanol (analytically pure, 97% purity) is tin-free and is produced by chemical company Limited; sodium sulfamate (industrial grade) is produced by Tianzhi chemical limited company of Qinhuang island in Hebei; the diethyl zinc catalyst (industrial grade) is produced by Shanghai Haosheng chemical technology limited company.

Example 1

Step one, weighing 9.8kg of vinyl oxirane and 15kg of absolute ethyl alcohol solution, and putting the vinyl oxirane and the absolute ethyl alcohol solution into a reaction kettle provided with a stirrer, a thermometer, a dropping funnel and a reflux condenser tube. The stirrer was started to stir for 35 minutes to mix the vinyl oxirane with absolute ethanol to a uniform, clear solution. 326kg of a dihydro-terminated polydimethylsiloxane oligomer was added to the mixed solution. 1.51kg of a 99.5% pure diethylzinc solution was slowly added dropwise over 50min while maintaining the solution temperature at 45 ℃. After the diethyl zinc catalyst is added dropwise, the temperature is raised to 65 ℃ for reaction for 9 hours. And (3) distilling under reduced pressure to remove the absolute ethyl alcohol solvent to obtain a faint yellow block type polydimethylsiloxane oligomer viscous liquid with epoxy groups connected at two ends.

Step two, 336kg of block-type polydimethylsiloxane oligomer with epoxy groups connected at two ends and 13.45kg of sodium sulfamate are added into a reaction kettle with a stirrer, a thermometer and a reflux condenser pipe, 650kg of water is added, and the mixture is stirredAnd (3) dissolving the solution in water completely, wherein the two ends of the solution are connected with epoxy groups and the block-type polydimethylsiloxane oligomer and the sodium sulfamate are dissolved in the water completely. Adding 10kg of sodium hydroxide with the mass fraction concentration of 20% to adjust the pH value of the system to 9.08, heating to 80 ℃, carrying out ring-opening reaction on epoxy groups in the block-type polydimethylsiloxane oligomer and active hydrogen in sodium sulfamate, changing the color of reactants from light yellow to light black, and reacting for 7 hours at the temperature of 80 ℃ to obtain a product with-OH and-NHSO ₃ Segmented polydimethylsiloxane oligomers of Na.

Step three, connecting 1000kg of the above-mentioned material with-OH and-NHSO ₃ Quickly stirring the block-type polydimethylsiloxane oligomer of Na, adjusting the pH to 14.56 by using sodium hydroxide with the mass fraction concentration of 20 percent, heating to 95 ℃, and adding-OH and-NHSO ₃ Na block type polydimethylsiloxane oligomer is subjected to intermolecular polycondensation and dehydration reaction and reacts for 6 hours at the temperature of 95 ℃ to prepare the product containing-SO ₃ and-NH group block type polydimethylsiloxane high polymer, measuring the weight average molecular weight of the block type polydimethylsiloxane high polymer to be 26865, reacting for 6 hours, adding a sodium hydroxide solution with the mass fraction concentration of 20%, adjusting the pH value to be 10.18, cooling to the ambient temperature of 25 ℃, and curing for 2 hours. The pH value is 11.22, the solid content is 28.56 percent, and the light black-SO-containing ₃ And the block-type organic silicon modified polycondensate mud-resistant high-efficiency water reducing agent with-NH groups is marked as HPVSSP.

Example 2

Step one, weighing 10kg of vinyl oxirane and 16kg of absolute ethanol solution, and putting the vinyl oxirane and the absolute ethanol solution into a reaction kettle provided with a stirrer, a thermometer, a dropping funnel and a reflux condenser tube. The stirrer was started and stirred for 40 minutes to mix the vinyloxirane with absolute ethanol into a homogeneous, clear solution. To the mixed solution was added 330kg of a dihydro-terminated polydimethylsiloxane oligomer. The temperature of the solution was maintained at 40 ℃ and 1.52kg of a 99.8% pure diethylzinc solution was slowly added dropwise over 60min. After dropping the diethyl zinc catalyst, heating to 60 ℃ and reacting for 10h. And (3) distilling under reduced pressure to remove the absolute ethyl alcohol solvent to obtain a faint yellow block type polydimethylsiloxane oligomer viscous liquid with epoxy groups connected at two ends.

Step two, mixing340kg of block-type polydimethylsiloxane oligomer with epoxy groups connected at two ends and 13.46kg of sodium sulfamate are added into a reaction kettle provided with a stirrer, a thermometer and a reflux condenser tube, 660kg of water is added, and the mixture solution is stirred, so that the block-type polydimethylsiloxane oligomer with epoxy groups connected at two ends and the sodium sulfamate are completely dissolved in the water. Adding 15kg of sodium hydroxide with the mass fraction concentration of 20% to adjust the pH value of the system to 10.34, heating to 75 ℃, carrying out ring opening reaction on epoxy groups in the block-type polydimethylsiloxane oligomer and active hydrogen in sodium sulfamate, changing the color of reactants from light yellow to light black, and reacting for 6 hours at the temperature of 75 ℃ to obtain a product with-OH and-NHSO ₃ Segmented polydimethylsiloxane oligomers of Na.

Step three, connecting 1010kg of the above-mentioned raw materials with-OH and-NHSO ₃ Quickly stirring the block-type polydimethylsiloxane oligomer of Na, adjusting the pH to 15 by using sodium hydroxide with the mass fraction concentration of 20%, heating to 90 ℃, and adding-OH and-NHSO ₃ Na block type polydimethylsiloxane oligomer is subjected to intermolecular polycondensation and dehydration reaction and reacts for 5 hours at the temperature of 90 ℃ to prepare the product containing-SO ₃ And a block-type polydimethylsiloxane high polymer of-NH group, and the weight average molecular weight of the block-type polydimethylsiloxane high polymer is 26978. After 5 hours of reaction, sodium hydroxide solution with the mass fraction concentration of 20 percent is added, the pH value is adjusted to 11.31, the mixture is cooled to the ambient temperature of 25 ℃ and cured for 3 hours. The pH value is 12.59, the solid content is 30 percent, and the light black product contains-SO ₃ and-NH group block type organosilicon modified polycondensate mud-resistant high-efficiency water reducing agent.

Example 3

Step one, weighing 9.9kg of vinyl oxirane and 15.5kg of absolute ethyl alcohol solution, and putting the vinyl oxirane and the absolute ethyl alcohol solution into a reaction kettle provided with a stirrer, a thermometer, a dropping funnel and a reflux condenser tube. The stirrer was started to stir for 35 minutes to mix the vinyl oxirane with absolute ethanol to a uniform, clear solution. 328kg of a dihydro-terminated polydimethylsiloxane oligomer was added to the mixed solution. 1.51kg of a 99.6% pure diethylzinc solution were slowly added dropwise over 50min, maintaining the solution temperature at 45 ℃. After dropping the diethyl zinc catalyst, the temperature is raised to 65 ℃ for reaction for 9h. And (3) distilling under reduced pressure to remove the absolute ethyl alcohol solvent to obtain a faint yellow block type polydimethylsiloxane oligomer viscous liquid with epoxy groups connected at two ends.

And step two, adding 338kg of block-type polydimethylsiloxane oligomer with epoxy groups connected at two ends and 13.45kg of sodium sulfamate into a reaction kettle with a stirrer, a thermometer and a reflux condenser pipe, adding 650kg of water, and stirring the mixture solution to completely dissolve the block-type polydimethylsiloxane oligomer with epoxy groups connected at two ends and the sodium sulfamate in the water. Adding 10kg of sodium hydroxide with the mass fraction concentration of 20% to adjust the pH value of the system to 9.78, heating to 80 ℃, performing ring opening reaction on epoxy groups in the block-type polydimethylsiloxane oligomer and active hydrogen in the sodium sulfamate, changing the color of reactants from light yellow to light black, and reacting for 7 hours at the temperature of 80 ℃ to obtain a product with-OH and-NHSO ₃ Segmented polydimethylsiloxane oligomers of Na.

Step three, connecting 1000kg of the above-mentioned material with-OH and-NHSO ₃ Rapidly stirring Na block-type polydimethylsiloxane oligomer, adjusting pH to 14.38 with 20% sodium hydroxide, heating to 95 deg.C, and adding water to obtain a mixture containing-OH and-NHSO ₃ Na block type polydimethylsiloxane oligomer is subjected to intermolecular polycondensation and dehydration reaction and reacts for 6 hours at the temperature of 95 ℃ to prepare the-SO-containing polydimethylsiloxane ₃ and-NH group, measuring the weight-average molecular weight of the block-type polydimethylsiloxane high polymer to be 27051, reacting for 6 hours, adding a sodium hydroxide solution with the mass fraction concentration of 20%, adjusting the pH value to be 10.47, cooling to the ambient temperature of 25 ℃, and curing for 2 hours. The pH value is 11.53, the solid content is 25 percent, and the light black product contains-SO ₃ and-NH group block type organosilicon modified polycondensate mud-resistant high-efficiency water reducing agent.

Comparative example

A conventional organic silicon modified polycarboxylic acid high-efficiency water reducing agent (Si-PCE SP) prepared according to the prior patent technology (CN 105271885A, a mud-resistant slump-retaining polycarboxylic acid high-performance water reducing agent and a preparation method thereof).

Example 4

The HPVSSP of example 1 and the Si-PCE SP of the comparative example were subjected to appearance fixationContent, weight average molecular weight, pH value, alkali content, na ₂ SO ₄ 、Cl ^- And (4) analyzing content homogeneity indexes. See table 1.

TABLE 1 homogeneity comparison of HPVSS SP and Si-PCE SP

	HPVSS SP	Si-PCE SP
			Appearance of the product	Light black clear liquid	Dark black liquid
Solid content (%)	28.56	32.09
			Weight average molecular weight (Da)	26865	14632
pH value	11.22	13.39
			Alkali content (%)	2.19	0.56
Na ₂ SO ₄ Content (%)	0.053	0.0034
			Cl ^- Content (%)	0.016	0.177
Surface tension (mN/m)	14.25	32.03

Example 5

Physical and chemical properties of HPVSSP SP of example 1 and Si-PCE SP of comparative example were compared

1. Water-resistant stability of two anti-mud high-efficiency water reducing agents

The water stability of the organosilicon modified anti-mud high-efficiency water reducing agent is an important index of the physical properties of the anti-mud high-efficiency water reducing agent. In order to evaluate the stability of the two types of anti-mud superplasticizers in water, the two types of anti-mud superplasticizers were allowed to stand at room temperature for 1,7, 28, and 90 days, and then the changes in the appearance states of the two types of anti-mud superplasticizers were observed in different standing times. Meanwhile, the weight average molecular weights (M) of the two anti-mud type high-efficiency water reducing agents were measured at different standing times by using a model 515 gel permeation chromatograph manufactured by Waters corporation of America _w ). During the detection, an Ultrahydrogel 250 Column chromatography is used, and the temperature of the Column chromatography is 40 ℃. The mobile phase was 0.1M NaCl, the rate of the mobile phase was 0.6ml/min, and polyethylene glycols of different molecular weights were used as standards. See in particular Table 2

TABLE 2 Water stability of HPVSS SP and Si-PCE SP

Table 2 shows the water stability of two types of anti-mud superplasticizers. From the table, it was found that the water resistance of both the anti-sludge type superplasticizers was deteriorated with the increase of the standing time. The high-efficiency water reducing agent containing sulfonic acid group and amino block type organic silicon polycondensate (HPVSS) has lower solid precipitation than the high-efficiency water reducing agent of the conventional organic silicon modified polycarboxylic acid (Si-PCE) in the same standing time. As the standing time is increased, the weight average molecular weight of the two anti-mud type high-efficiency water reducing agents is reduced. The weight average molecular weight of the sulfonic acid group and amino block type organic silicon polycondensate (HPVSS) high-efficiency water reducing agent is reduced less than that of the conventional organic silicon modified polycarboxylic acid (Si-PCE) high-efficiency water reducing agent. The block-type organic silicon modified polycondensate of sulfonic group and amino group has better long-term storage stability than the conventional organic silicon modified polycarboxylic acid mud-resistant high-efficiency water reducing agent.

2. Under different concentrations, the surface tension of two anti-mud high-efficiency water reducing agent solutions

Preparing mud-resistant superplasticizer solutions with different concentrations, then putting the mud-resistant superplasticizer solutions into a test container, and soaking a platinum-iridium metal ring in the mud-resistant superplasticizer solutions. And finally, slowly lifting the platinum iridium ring from the anti-mud type high efficiency water reducing agent solution until the platinum iridium ring is separated from the anti-mud type high efficiency water reducing agent solution, wherein the maximum force value when the platinum iridium ring is broken is defined as the surface tension of the anti-mud type high efficiency water reducing agent solution.

Referring to FIG. 2, as the concentration of the two types of anti-mud superplasticizer solutions increases, the surface tension of both types of anti-mud superplasticizers decreases. Under the same concentration of the high-efficiency water reducing agent solution, the block-type organic silicon modified polycondensate of the sulfonic group and the amino group has lower surface tension than that of the conventional organic silicon modified polycarboxylic acid mud-resistant high-efficiency water reducing agent. This shows that the block-type organic silicon modified polycondensate of sulfonic acid group and amino group has better surface activity than the conventional organic silicon modified polycarboxylic acid anti-mud type high efficiency water reducing agent.

Example 6

Water reduction and concrete performance of HPVSS SP of example 1 and Si-PCE SP of comparative example.

Concrete preparation material

The cement is 52.5 Portland cement grade PII in south of the Yangtze river, the fine aggregate is river sand, the grain diameter is less than 5mm, and the fineness modulus of the fine aggregate is 2.46. The coarse aggregate is continuous graded broken stone, the broken stone is secondary graded broken stone, 5-20mm broken stone accounts for 40%, and 20-40mm broken stone accounts for 60%.

Concrete mixing proportion doped with two anti-mud type high-efficiency water reducing agents

0-0.6 percent of HPVSSP is added into the concrete, and the performance of the concrete is compared and researched with that of Si-PCESP concrete under the same doping amount. In the single-component concrete mixture, the dosage of cement is 330kg/m ³ The coarse aggregate is 1158kg/m ³ The sand rate was 39%. Adjusting the dosage of mixing water, and controlling the slump constant of concrete to be 70-90mm. The concrete formulation of the two types of anti-mud superplasticizers is shown in Table 3.

TABLE 3 Experimental mix proportion of concrete

Preparation and maintenance of concrete doped with two anti-mud high-efficiency water reducing agents

Putting 330kg of cement, 710kg of fine aggregate, 690-700kg of 20-40mm coarse aggregate and 460-465kg of 5-20mm coarse aggregate into a vertical stirrer, and mixing for 1-2 minutes at a stirring speed of 30 revolutions per minute. Then, 150-181kg of mixed water blended with a high-efficiency water reducing agent containing sulfonic acid groups and amino block type organosilicon modified polycondensate (HPVSS) and a high-efficiency water reducing agent of conventional organosilicon modified polycarboxylic acid (Si-PCE) is added into a stirrer, and stirring is continued for 1-2 minutes at the speed of 30 revolutions per minute. In order to avoid the mixture from being laminated at the bottom of the container, a shovel is used for manually stirring the slurry for 1-2 times. And finally, stirring at a stirring speed of 60 revolutions per minute for 2 minutes at an accelerated speed, removing air bubbles in the slurry of the fresh concrete, and measuring the initial slump fluidity of the fresh concrete to be 70-90mm. According to the GB 8076-1997 method, a penetration resistance instrument is adopted to measure the setting time of the concrete doped with the HPVSS and the Si-PCE high-efficiency water reducing agent. Finally, the fresh concrete is poured into a test mould of 100mm × 100mm × 100mm, and placed indoors (temperature 25 ℃, humidity 55-65%) for 24 hours. And (3) removing the concrete doped with the HPVSS high-efficiency water reducing agent and the Si-PCE high-efficiency water reducing agent from the test mould after 1 day, placing the concrete in an environment with the temperature of 20 ℃ and the humidity of 90 +/-5 percent for curing for 3,7, and detecting the compressive strength of the concrete after 28 days.

Referring to fig. 3, as the blending amount of the two high-efficiency water reducing agents is increased, the water reducing rates of the high-efficiency water reducing agent containing sulfonic acid groups and amino block type organosilicon polycondensate (HPVSS SP) and the high-efficiency water reducing agent containing conventional organosilicon modified polycarboxylic acid (Si-PCE SP) are increased. Under the same mixing amount, the conventional organic silicon modified polycarboxylic acid (Si-PCESP) high-efficiency water reducing agent has a slightly better water reducing rate than a sulfonic acid group-containing and amino block type organic silicon polycondensate (HPVSS SP) high-efficiency water reducing agent.

Referring to fig. 4 and 5, as the mixing amount of the two anti-mud high-efficiency water reducing agents is increased, the initial setting time and the final setting time of the concrete are increased. At the same dosage, the concrete doped with the high-efficiency water reducing agent containing sulfonic acid group and amino block type organosilicon polycondensate (HPVSSP) has longer setting time than the concrete doped with the high-efficiency water reducing agent of the conventional organosilicon modified polycarboxylic acid (Si-PCESP)).

Referring to fig. 6 and 7, under the condition of the same concrete fluidity, the addition of the anti-mud high efficiency water reducing agent reduces the amount of concrete mixing water and increases the compressive strength of the concrete. With the increase of the curing age, the compressive strength of the concrete is continuously increased. In the same mixing amount and curing age, the concrete doped with the conventional organic silicon modified polycarboxylic acid (Si-PCE) high-efficiency water reducing agent has slightly higher compressive strength than the concrete doped with the sulfonic group-containing and amino block type organic silicon polycondensate (HPVSS) high-efficiency water reducing agent.

Example 7

Mud resistance of HPVSS SP of example 1 and Si-PCE SP of comparative example.

Concrete mixing proportion doped with two anti-mud high-efficiency water reducing agents

In order to investigate the mud-resistant effect of the HPVSS high-efficiency water reducing agent and the Si-PCE high-efficiency water reducing agent, the mixing amount of the HPVSS SP high-efficiency water reducing agent and the Si-PCE SP high-efficiency water reducing agent is fixed to be 0.5 percent. P, I42.5 ordinary silica cement, nanjing power plant secondary fly ash, 5-25mm coarse aggregate continuous graded broken stone and fine aggregate river sand fineness modulus of 2.15 are used. The mud content of the river sand fine aggregate is 5.98%, and the part of the mud-containing river sand fine aggregate is completely washed to obtain the river sand fine aggregate with the mud content of 0%, 3.07% and 5.98%. And (3) airing the river sand fine aggregate with the mud content of 0%, 3.07% and 5.98% indoors for 24 hours to obtain the saturated surface dry river sand fine aggregate. The concrete mixing ratio in Table 4 was measured.

Table 4 concrete experimental mixing proportion of two high-efficiency water reducing agents with anti-mud effect

Mud resistance performance detection of two mud-resistant type high-efficiency water reducing agents

Putting 360-370kg of cement, 90-95kg of fly ash, 690-670kg of river sand fine aggregate and 1050-1100kg of coarse aggregate into a vertical stirrer, and mixing for 1-2 minutes at the stirring speed of 30 revolutions per minute. And then adding 161kg of HPVSS high-efficiency water reducing agent or Si-PCE high-efficiency water reducing agent mixed water into a stirrer, stirring for 1-2 minutes at a stirring speed of 30 revolutions per minute, and manually stirring the slurry for 1-2 times by using an iron shovel to avoid the mixture from being laminated at the bottom of the container. And finally, mixing at a stirring speed of 60 revolutions per minute for 2 minutes at an accelerated speed, removing air bubbles in the slurry of the fresh concrete, and measuring the initial slump fluidity of the fresh concrete. The fresh concrete was placed in a metal container, and after 30, 60, 90, and 120 minutes of placement, the slump flow of the concrete was determined again, and the slump flow retention of the fresh concrete was evaluated. And simultaneously, preparing and curing the concrete according to a detection method specified by the performance part of the high-efficiency water reducing agent, and respectively taking 3 test pieces of 100mm multiplied by 100mm and 150mm multiplied by 550mm to detect the compressive strength and the breaking strength of the concrete in curing ages of 3,7 and 28 days. The mud resistance effects of the HPVSS SP high-efficiency water reducing agent and the Si-PCE SP high-efficiency water reducing agent are evaluated by measuring the slump fluidity retentivity and the mechanical properties of the two mud resistance type high-efficiency water reducing agents.

Referring to fig. 8 and 9, when the amount of fine aggregate containing mud is zero, the concrete doped with the conventional organosilicon-modified polycarboxylic acid (Si-PCE) superplasticizer has higher initial slump and better slump retention than the concrete doped with the sulfonic acid group-containing, amino block-type organosilicon condensation polymer (HPVSS) superplasticizer. As the mud content increases, the initial flow performance of the concrete doped with the two mud-resistant high-efficiency water reducing agents is reduced. Under the condition of the same mud content, the concrete doped with the efficient water reducing agent containing sulfonic acid groups and amino block type organosilicon polycondensates (HPVSS) has better initial slump and slump retention than the concrete doped with the efficient water reducing agent of conventional organosilicon modified polycarboxylic acids (Si-PCE). The high-efficiency water reducing agent containing sulfonic acid group and amino block type organic silicon polycondensate (HPVSS) has better mud resistance than the conventional organic silicon modified polycarboxylic acid (Si-PCE) high-efficiency water reducing agent.

Referring to fig. 10 and 11, the compressive strength of the concrete samples doped with both of the anti-mud superplasticizers increased with the increase of the curing age. In the same curing period, the compressive strength of the concrete is reduced along with the increase of the mud content in the fine aggregate. The concrete doped with the efficient water reducing agent containing sulfonic acid groups and amino block type organic silicon polycondensates (HPVSS) has higher compressive strength than the concrete doped with the efficient water reducing agent of conventional organic silicon modified polycarboxylic acids (Si-PCE) in the same mud content and the same curing age.

Referring to fig. 12 and 13, the flexural strength of the concrete samples doped with the two mud-resistant superplasticizers increased with the increase of the curing age. In the same curing period, the flexural strength of the concrete is reduced along with the increase of the mud content in the fine aggregate. The concrete doped with the efficient water reducing agent containing sulfonic acid groups and amino block type organic silicon polycondensates (HPVSS) has higher breaking strength than the concrete doped with the efficient water reducing agent of conventional organic silicon modified polycarboxylic acids (Si-PCE) in the same mud content and the same curing age.

Claims

1. The preparation method of the block-type organosilicon polycondensate anti-mud high-efficiency water reducer is characterized by comprising the following steps of:

(2) Mixing and stirring the block-type polydimethylsiloxane oligomer with epoxy groups connected at two ends, sodium sulfamate and water to form a uniform and clear solution, adjusting the pH value of the solution to 9-10, and carrying out ring-opening reaction to obtain the block-type polydimethylsiloxane oligomer with hydroxyl groups, amino groups and sulfonic groups connected at two ends;

(3) Rapidly stirring a block-type polydimethylsiloxane oligomer solution with hydroxyl groups, amino groups and sulfonic groups connected at two ends, adjusting the pH of the solution to be 14 to 15, and performing intermolecular dehydration polycondensation to prepare a block-type polydimethylsiloxane polymer with sulfonic groups and amino groups at two ends;

(4) And (3) adjusting the pH of the system to 10 to 11 at the later reaction stage, and cooling and curing to obtain the block-type organic silicon polycondensate anti-mud high-efficiency water reducer containing sulfonic groups and amino groups.

2. The preparation method of the block-type organosilicon polycondensate mud-resistant high-efficiency water reducer according to claim 1, characterized in that: in the step (1), the mass ratio of the vinyl oxirane, the absolute ethanol solution, the dihydro-terminated polydimethylsiloxane oligomer to the diethyl zinc solution is 9.8 to 10:15 to 16:326 to 330:1.51 to 1.52; wherein the purity of the diethyl zinc solution is 99.5-99.8%.

3. The preparation method of the block-type organosilicon polycondensate mud-resistant superplasticizer according to claim 1, which is characterized by comprising the following steps: in the step (1), when the diethyl zinc solution is dripped, the system temperature is kept at 40 to 50 ℃, and the dripping time is 45 to 60min.

4. The preparation method of the block-type organosilicon polycondensate mud-resistant superplasticizer according to claim 1, which is characterized by comprising the following steps: in the step (1), the reaction temperature after the diethyl zinc catalyst solution is dripped is 60 to 65 ℃, and the reaction time is 8 to 10 hours.

5. The preparation method of the block-type organosilicon polycondensate mud-resistant high-efficiency water reducer according to claim 1, characterized in that: in the step (2), the mass ratio of the block-type polydimethylsiloxane oligomer with epoxy groups connected at two ends to the sodium sulfamate is 336-340: 13.4 to 13.5.

6. The preparation method of the block-type organosilicon polycondensate mud-resistant superplasticizer according to claim 1, which is characterized by comprising the following steps: in the step (2), the ring-opening reaction temperature is 75-80 ℃, and the reaction time is 6-7 h.

7. The preparation method of the block-type organosilicon polycondensate mud-resistant high-efficiency water reducer according to claim 1, characterized in that: in the step (3), the reaction temperature of intermolecular high-temperature dehydration polycondensation is 90 to 95 ℃, and the reaction time is 5 to 6 hours.

8. The preparation method of the block-type organosilicon polycondensate mud-resistant superplasticizer according to claim 1, which is characterized by comprising the following steps: in the step (4), the cooling curing time is 2 to 3 hours, and the cooling temperature is 20 to 25 ℃.

9. The preparation method of the block-type organosilicon polycondensate mud-resistant high-efficiency water reducer according to claim 1, characterized in that: in the step (2), the step (3) and the step (4), the pH is adjusted by using a sodium hydroxide solution, and the mass fraction concentration of the sodium hydroxide solution is 20%.

10. The preparation method of the block-type organosilicon polycondensate mud-resistant high-efficiency water reducer according to claim 1, characterized in that: in the step (4), the weight average molecular weight of the organosilicon polycondensate anti-mud high-efficiency water reducing agent is 26456 to 27139, the pH value is 11 to 12, and the solid content is 23 to 30%.