阅读说明：本技术 一种用丙烯酸和羟基硅油酯合成聚羧酸减水剂的方法 (Method for synthesizing polycarboxylate superplasticizer by using acrylic acid and hydroxyl silicone oil ester ) 是由 徐大勇 林磊 曾锦涛 于 2021-07-31 设计创作，主要内容包括：本发明提供了一种用丙烯酸和羟基硅油酯合成聚羧酸减水剂的方法,包括按顺序进行的如下步骤：(1)取一不锈钢反应釜中,加入EPEG大单体,加温至75-80℃,使EPEG大单体处于熔融状态；(2)加入羟基硅油酯化物和链转移剂,搅拌均匀,同时滴加丙烯酸或甲基丙烯酸和滴加过硫酸铵水溶液；其中,丙烯酸或甲基丙烯酸滴加时间50-60分钟,过硫酸铵水溶液滴加时间55-60分钟,滴加温度控制在75-85℃；滴加完毕,保温90-150分钟；(3)放料冷却,得到固体聚羧酸减水剂。本发明所述的用丙烯酸和羟基硅油酯合成聚羧酸减水剂的方法,得到聚羧酸减水剂,0.2％掺量减水率达到31％,混凝土出机含气量达到3.5％,3小时含气量达到2.0％,1小时经时塌落度损失小于20mm,抗压强度优异。(The invention provides a method for synthesizing a polycarboxylic acid water reducing agent by using acrylic acid and hydroxyl silicone oil ester, which comprises the following steps in sequence: (1) adding an EPEG macromonomer into a stainless steel reaction kettle, heating to 75-80 ℃ to ensure that the EPEG macromonomer is in a molten state; (2) adding hydroxyl silicone oil esterified substance and chain transfer agent, stirring uniformly, and simultaneously dripping acrylic acid or methacrylic acid and ammonium persulfate aqueous solution; wherein, the dripping time of acrylic acid or methacrylic acid is 50-60 minutes, the dripping time of ammonium persulfate aqueous solution is 55-60 minutes, and the dripping temperature is controlled at 75-85 ℃; after the dripping is finished, preserving the heat for 90-150 minutes; (3) discharging and cooling to obtain the solid polycarboxylic acid water reducing agent. According to the method for synthesizing the polycarboxylate superplasticizer by using the acrylic acid and the hydroxy silicone oil, the polycarboxylate superplasticizer is obtained, the 0.2% doping amount water reducing rate reaches 31%, the air content of the concrete discharged from the machine reaches 3.5%, the air content of the concrete discharged from the machine reaches 2.0% in 3 hours, the slump loss of the concrete discharged from the machine is less than 20mm in 1 hour, and the compressive strength is excellent.)

1. A method for synthesizing a polycarboxylic acid water reducing agent by using acrylic acid and hydroxyl silicone oil ester is characterized by comprising the following steps in sequence:

(1) adding an EPEG macromonomer into a stainless steel reaction kettle, heating to 75-80 ℃ to ensure that the EPEG macromonomer is in a molten state;

(2) adding hydroxyl silicone oil esterified substance and chain transfer agent, stirring uniformly, and simultaneously dripping acrylic acid or methacrylic acid and ammonium persulfate aqueous solution; wherein, the dripping time of acrylic acid or methacrylic acid is 50-60 minutes, the dripping time of ammonium persulfate aqueous solution is 55-60 minutes, and the dripping temperature is controlled at 75-85 ℃; after the dripping is finished, preserving the heat for 90-150 minutes;

(3) discharging and cooling to obtain the solid polycarboxylic acid water reducing agent.

2. The method for synthesizing the polycarboxylate superplasticizer by using the acrylic acid and the hydroxyl silicone oil ester as claimed in claim 1, wherein the preparation method of the hydroxyl silicone oil esterified substance is as follows: adding hydroxyl silicone oil containing 5 silicon atoms, acrylic acid, hydroquinone and p-toluenesulfonic acid into an esterification reaction kettle for mixing, introducing nitrogen for 10 minutes, heating to 105-108 ℃, carrying out esterification reaction for 3 hours, wherein during the esterification reaction, the acrylic acid and water are atomized and evaporated, cooled by a condenser, collected, and added into the reaction kettle after the esterification reaction is finished.

3. The method for synthesizing the polycarboxylate superplasticizer by using the acrylic acid and the hydroxy silicone oil ester as claimed in claim 2, wherein in the preparation method of the hydroxy silicone oil esterified substance, the dosage of each raw material is as follows: 250 parts of hydroxyl silicone oil containing 5 silicon; 145 parts of acrylic acid or methacrylic acid; 0.35 part of hydroquinone; 3.7 parts of p-toluenesulfonic acid.

4. The method for synthesizing the polycarboxylate superplasticizer by using the acrylic acid and the hydroxyl silicone oil ester as claimed in claim 1, wherein the dosage of each component is as follows: 4300 parts of EPEG macromonomer, 180 parts of hydroxyl silicone oil esterified substance 130-and 16-18.5 parts of chain transfer agent; 375-430 parts of acrylic acid or methacrylic acid; ammonium persulfate aqueous solution, wherein the content of ammonium persulfate is 45-55 parts, and the content of water is 55-100 parts.

5. The method for synthesizing the polycarboxylate superplasticizer by using the acrylic acid and the hydroxy silicone oil ester as claimed in claim 1, wherein the solid content of the obtained polycarboxylate superplasticizer is 97.83% -98.76%.

6. The method for synthesizing the polycarboxylate superplasticizer by using the acrylic acid and the hydroxyl silicone oil as claimed in claim 1, wherein the chain transfer agent is one or a combination of several of mercaptoethanol, mercaptoacetic acid, mercaptopropionic acid and mercaptoethylamine.

Technical Field

The invention relates to the technical field of water reducing agents, in particular to a method for synthesizing a polycarboxylic acid water reducing agent by using hydroxy silicone acrylate.

Background

The preparation process of the novel environment-friendly water reducing agent comprises the steps of firstly, preparing vinyl polyethylene glycol with polymer activity, namely polyether macromonomer, by using unsaturated monomers such as allyl alcohol, methyl allyl alcohol and isopentenol as initiators and catalyzing under an alkaline condition, and then, preparing the polycarboxylic acid water reducing agent by utilizing the prepared macromonomer to perform polymerization reaction with acrylic acid and functional unsaturated monomers.

The Chinese invention patent with the patent number ZLCN201010101070.8 discloses a polycarboxylate superplasticizer and a preparation method thereof, wherein the polycarboxylate superplasticizer is a polymer which is copolymerized by A, B, C three monomers and has the weight-average molecular weight of 10000-30000; wherein the molar ratio of the monomer A to the monomer B is 0.1-0.5: 1, and the molar ratio of the monomer A to the monomer C is 5-10: 1; the monomer A is monohydroxy silicone oil polyoxyethylene ether acrylate, and the structure is shown as the following formula (I), wherein R1 and R2 are methyl or amino; m is an integer of 1 to 10; n is an integer of 13 to 49; the monomer B is one of maleic anhydride, maleic acid, acrylic acid or methacrylic acid; the monomer C is one of sodium vinyl sulfonate, sodium propenyl sulfonate, sodium methyl propylene sulfonate, sodium styrene sulfonate, 2-acrylamide-2-methyl propane sulfonic acid, methyl methacrylate, methyl acrylate or vinyl acetate. The water reducing agent disclosed by the invention has the advantages of stable performance, high water reducing rate, strong cement adaptability, high air entraining performance and no pollution to the environment. The invention also provides a preparation method of the water reducing agent, and the preparation method has the advantages of simple process, strong operability, low energy consumption and the like.

However, the method is complex, the production cost is high, the water reducing rate of the produced water reducing agent is low, the cement adaptability is poor, the air entraining property is poor, the pressure resistance is low, and the requirements of users cannot be met.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a method for synthesizing a polycarboxylate superplasticizer by using acrylic acid and hydroxy silicone oil ester, and overcomes the defects of low water reducing rate and obviously low compressive strength of the polycarboxylate superplasticizer in the prior art.

The technical scheme of the invention is as follows: a method for synthesizing a polycarboxylic acid water reducing agent by using acrylic acid and hydroxyl silicone oil ester comprises the following steps in sequence:

(1) adding an EPEG macromonomer into a stainless steel reaction kettle, heating to 75-80 ℃ to ensure that the EPEG macromonomer is in a molten state;

(2) adding hydroxyl silicone oil esterified substance and chain transfer agent, stirring uniformly, and simultaneously dripping acrylic acid or methacrylic acid and ammonium persulfate aqueous solution; wherein, the dripping time of acrylic acid or methacrylic acid is 50-60 minutes, the dripping time of ammonium persulfate aqueous solution is 55-60 minutes, and the dripping temperature is controlled at 75-85 ℃; after the dripping is finished, preserving the heat for 90-150 minutes;

(3) discharging and cooling to obtain the solid polycarboxylic acid water reducing agent.

The preparation method of the hydroxyl silicone oil esterification product comprises the following steps: adding hydroxyl silicone oil containing 5 silicon atoms, acrylic acid, hydroquinone and p-toluenesulfonic acid into an esterification reaction kettle for mixing, introducing nitrogen for 10 minutes, heating to 105-108 ℃, carrying out esterification reaction for 3 hours, wherein during the esterification reaction, the acrylic acid and water are atomized and evaporated, the acrylic acid and water are collected after being cooled by a condenser, and the acrylic acid and water are added into the reaction kettle after the esterification reaction is finished.

In the preparation method of the hydroxyl silicone oil esterification product, the dosage of each raw material is as follows: 250 parts of hydroxyl silicone oil containing 5 silicon; 145 parts of acrylic acid or methacrylic acid; 0.35 part of hydroquinone; 3.7 parts of p-toluenesulfonic acid.

The dosage of each component is as follows: 4300 parts of EPEG macromonomer, 180 parts of hydroxyl silicone oil esterified substance 130-and 16-18.5 parts of chain transfer agent; 375-430 parts of acrylic acid or methacrylic acid; ammonium persulfate aqueous solution, wherein the content of ammonium persulfate is 45-55 parts, and the content of water is 55-100 parts.

The solid content of the obtained polycarboxylate superplasticizer is 97.83-98.76%.

The chain transfer agent is one or a combination of several of mercaptoethanol, mercaptoacetic acid, mercaptopropionic acid and mercaptoethylamine.

The invention adopts acrylic acid or methacrylic acid and hydroxyl silicone oil to carry out esterification to obtain a mixture of acrylic acid monoester and diester, and then carries out polymerization with a macromonomer and acrylic acid/methacrylic acid.

Due to the hydrophobicity and unique characteristics of the hydroxyl silicone oil, the hydroxyl silicone oil has better adsorption on concrete gelled material particles in polycarboxylic acid molecules, so that the hydroxyl silicone oil has better dispersing performance on cement and other particles.

In the using process and under the alkaline condition of concrete, the acrylic hydroxyl silicone oil ester is hydrolyzed into a water reducing agent with proper dispersion function of molecular weight and molecular structure by a crosslinking molecular structure without dispersion function, thereby improving the collapse-protecting performance of concrete.

The acrylic hydroxyl silicone oil monoester is hydrolyzed into carboxylic acid anion under the concrete alkaline condition, and the principle of the acrylic hydroxyl silicone oil monoester is similar to the collapse-protecting action mechanism of a hydroxyethyl acrylate or hydroxypropyl acrylate water reducing agent. The difference is that acrylic hydroxyl silicone mono-ester or diester, hydroxyl silicone oil generated by hydrolysis has the function of reducing concrete bubbles before the concrete is cured, and the strength can be further improved under the condition of keeping the durability of the concrete.

The invention has the beneficial effects that: through detection, the polycarboxylic acid water reducing agent is obtained by the method for synthesizing the polycarboxylic acid water reducing agent by using the acrylic acid and the hydroxyl silicone oil ester, the water reducing rate of 0.2 percent is up to 31 percent, the air content of the concrete after the concrete is discharged from the machine is up to 3.5 percent, the air content of the concrete after 3 hours is up to 2.0 percent, and the slump loss after 1 hour is less than 20 mm. Compared with the blank control, the compressive strength of the obtained carboxylic acid water reducing agent is respectively greater than 180%, 175% and 160% of the blank control on the 3 rd day, the 7 th day and the 28 th day. Under the condition of the same material and the same dosage, the concrete compressive strength of the carboxylic acid water reducing agent obtained by the invention is as follows: compared with the common polycarboxylic acid high-performance water reducing agent (standard type), the water reducing agent is increased by 9 percent, 13 percent and 7 percent on the 3 rd day, the 7 th day and the 28 th day respectively.

The method for synthesizing the polycarboxylic acid water reducer by using the acrylic acid and the hydroxyl silicone oil ester has the advantages of simple production method, easy operation, low water content of the product and contribution to micro-pulverization reprocessing.

Detailed Description

In order to make the object, technical solution and technical effect of the present invention more apparent, the present invention will be further described with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Firstly, preparing hydroxyl silicone oil esterified substance: 250kg of hydroxyl silicone oil containing 5 silicon atoms, 145kg of acrylic acid, 0.35kg of hydroquinone and 3.7kg of p-toluenesulfonic acid are taken and added into a reaction kettle for mixing, then nitrogen is introduced for 10 minutes, the temperature is increased to 105-fold-material 108 ℃, esterification reaction is carried out for 3 hours, during the esterification reaction, the acrylic acid and water are atomized and evaporated, a condenser is used for cooling, then the acrylic acid and water are collected, and after the esterification is finished, the mixture is added into the reaction kettle. 396kg of hydroxyl silicone oil ester is finally obtained, wherein: contains 25.6% of acrylic diester, 53.5% of acrylic monoester, 15.1% of acrylic acid and 5.8% of water.

Embodiment 1. a method for synthesizing a polycarboxylic acid water reducer from acrylic acid and hydroxy silicone oil ester, comprising the following steps performed in sequence:

(1) adding 4300kg of EPEG macromonomer into a 5000L stainless steel reaction kettle, heating to 75-80 ℃ to ensure that the EPEG macromonomer is in a molten state;

(2) 150 kg of the hydroxyl silicone oil esterified substance and 17 kg of the chain transfer agent are added under stirring, after uniform stirring, 385 kg of acrylic acid is simultaneously dripped, and ammonium persulfate aqueous solution is dripped, wherein the ammonium persulfate aqueous solution contains 50kg of ammonium persulfate and 100kg of water; wherein, the dripping time of acrylic acid is 50 minutes, the dripping time of ammonium persulfate aqueous solution is 60 minutes, and the dripping temperature is controlled to be 75-80 ℃; after the dropwise addition, the mixture is kept at the temperature of between 75 and 80 ℃ for 100 and 120 minutes;

(3) discharging and cooling to obtain the solid polycarboxylic acid water reducing agent with the content of 97.85 percent.

Embodiment 2. a method for synthesizing a polycarboxylic acid water reducer from acrylic acid and hydroxy silicone oil ester, comprising the following steps performed in sequence:

(1) adding 4300kg of EPEG macromonomer into a 5000L stainless steel reaction kettle, heating to 75-80 ℃ to ensure that the EPEG macromonomer is in a molten state;

(2) adding 180 kg of the hydroxyl silicone oil esterified substance and 17 kg of the chain transfer agent under stirring, after stirring uniformly, simultaneously dropwise adding 375 kg of acrylic acid, and dropwise adding an ammonium persulfate aqueous solution, wherein the ammonium persulfate aqueous solution contains 45kg of ammonium persulfate and 100kg of water; wherein, the dripping time of acrylic acid is 60 minutes, the dripping time of ammonium persulfate aqueous solution is 55 minutes, and the dripping temperature is controlled to be 75-80 ℃; after the dropwise addition, the mixture is subjected to heat preservation at the temperature of between 75 and 80 ℃ for 150 minutes;

(3) discharging and cooling to obtain a solid polycarboxylic acid water reducing agent with the content of 97.83%.

Embodiment 3. a method for synthesizing a polycarboxylic acid water reducer from acrylic acid and hydroxy silicone oil ester, comprising the following steps performed in sequence:

(1) adding 4300kg of EPEG macromonomer into a 5000L stainless steel reaction kettle, heating to 75-80 ℃ to ensure that the EPEG macromonomer is in a molten state;

(2) adding 200 kg of the hydroxyl silicone oil esterified substance and 18.5 kg of the chain transfer agent under stirring, after stirring uniformly, simultaneously dropwise adding 430 kg of acrylic acid, and dropwise adding an ammonium persulfate aqueous solution, wherein the ammonium persulfate aqueous solution contains 55kg of ammonium persulfate and 100kg of water; wherein, the dripping time of acrylic acid is 50 minutes, the dripping time of ammonium persulfate aqueous solution is 55 minutes, and the dripping temperature is controlled to be 75-80 ℃; after the dropwise addition, the mixture is subjected to heat preservation at the temperature of between 75 and 80 ℃ for 150 minutes;

(3) discharging and cooling to obtain the solid polycarboxylic acid water reducing agent with the content of 97.85 percent.

Embodiment 4. a method for synthesizing a polycarboxylic acid water reducer from acrylic acid and hydroxy silicone oil ester, comprising the following steps performed in sequence:

(1) adding 4300kg of EPEG macromonomer into a 5000L stainless steel reaction kettle, heating to 75-80 ℃ to ensure that the EPEG macromonomer is in a molten state;

(2) adding 130 kg of the hydroxyl silicone oil esterified substance and 16 kg of the chain transfer agent under stirring, after stirring uniformly, simultaneously dropwise adding 390 kg of acrylic acid, and dropwise adding an ammonium persulfate aqueous solution, wherein the ammonium persulfate aqueous solution contains 55kg of ammonium persulfate and 55kg of water; wherein, the dripping time of acrylic acid is 55 minutes, the dripping time of ammonium persulfate aqueous solution is 60 minutes, and the dripping temperature is controlled to be 80-85 ℃; after the dropwise addition, preserving the heat for 90-100 minutes at 84-88 ℃;

(3) discharging and cooling to obtain the solid polycarboxylic acid water reducing agent with the content of 98.76 percent.

Embodiment 5. a method for synthesizing a polycarboxylic acid water reducer from acrylic acid and hydroxy silicone oil ester, comprising the following steps performed in sequence:

(1) adding 4300kg of EPEG macromonomer into a 5000L stainless steel reaction kettle, heating to 75-80 ℃ to ensure that the EPEG macromonomer is in a molten state;

(2) adding 16 kg of chain transfer agent while stirring, after uniformly stirring, simultaneously dropwise adding a mixture of 385 kg of acrylic acid and 130 kg of the hydroxyl silicone oil esterified substance, and dropwise adding an ammonium persulfate aqueous solution, wherein the ammonium persulfate aqueous solution contains 55kg of ammonium persulfate and 55kg of water; wherein, the dripping time of acrylic acid is 50 minutes, the dripping time of ammonium persulfate aqueous solution is 55 minutes, and the dripping temperature is controlled to be 75-80 ℃; after the dropwise addition, preserving the heat at 80-85 ℃ for 90-100 minutes;

(3) discharging and cooling to obtain the solid polycarboxylic acid water reducing agent with the content of 98.75 percent.

In order to verify the technical effects of the application, the applicant detects the polycarboxylic acid water reducer obtained in the examples 1 to 5 according to the standard high-performance water reducer of the national standard GB8076-2008 concrete admixture. The test items and the results obtained from the tests were as follows:

note: the detection doping amount is 0.2 percent of the broken fixation doping amount

The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. For those skilled in the art to which the present invention pertains, the architecture form can be flexible and varied without departing from the concept of the present invention, and a series of products can be derived. But rather a number of simple derivations or substitutions are made which are to be considered as falling within the scope of the invention as defined by the appended claims.