Efficient cement water reducing agent and preparation method thereof
Technical field
The invention belongs to concrete processing technique fields, and in particular, to a kind of efficient cement water reducing agent and its preparation
Method.
Background technique
Cement water reducing agent is moisture needed for for reducing concrete hardening, and then improves the additive of concrete strength,
Traditional cement water reducing agent is using naphthalene system and melamine system product as mainstream.In recent years, right as domestic and international construction industry flourishes
The demand of cement water reducing agent increases year by year, and concrete develops to high-strength, lightweight and construction fluidization direction, therefore also requires
Water-reducing agent has stronger dispersion and water-reduction and better function of slump protection.Due to traditional naphthalene system and melamine based water reducer
There are water-reducing rates it is not high, fresh concrete loss of slump is too fast the problems such as, it is difficult to it is increasingly sophisticated and big to meet Practical Project
The adaptability of the construction requirement of type, joint product and cement is also unstable, in addition influence concrete condensation hardening and
Endurance quality, and as the dosage of construction market water-reducing agent is bigger, problem is more aobvious to be protruded, and therefore, there is an urgent need to novel efficient
Water-reducing agent.
Require height resistance in water conservancy, road etc. in external some developed countries, such as the U.S., Japan, state, Italy at present
Maleic anhydride series, acrylic acid series high performance concrete water-reducing agent are widely applied in the concrete works of long property, though technology compares
Maturation, but it is complicated, the requirement to consersion unit is high since there is preparation processes the problems such as so that its answering in Practical Project
It is restricted in popularization.About the sight that research novel carboxylic acid based polymer water-reducing agent is in this field about high performance concrete
It reads after proposing, since studying reactive polymer maleic anhydride-alkene sulfonic acid salt copolymer, is mainly used as concrete slump
Spend damage control agent, in addition, the prior art there is also because water-reducing agent dosage is larger, protect collapse it is indifferent due to cannot fully demonstrate it
The problem of excellent water-reducing property.
Summary of the invention
The purpose of the present invention is to provide a kind of efficient cement water reducing agents and preparation method thereof, are subtracted with homemade polycarboxylic acids
Aqua is as main substance, hydrophilic groups (- COO-) that homemade polycarboxylate water-reducer contains, amino (- NH2), it is hydrophobic
The synergistic effect of group ester group (- COOR) and polyether lateral chain be conducive to its to the wetting of concrete and concrete particle surface,
Opposite lubrication between absorption and particles of aggregates;By the incorporation of defoaming agent, the air content of concrete mix is not only reduced,
The compactness for increasing concrete eliminates the air pocket unfavorable to intensity, can be improved the compression strength of concrete;By changing
Property lignin quantitative incorporation, modified lignin resin have certain bleed effect, in concrete can appropriate bleed, improve concrete
Workability and reduce concrete viscosity, have certain function of slump protection to concrete;A kind of efficient, function of slump protection is prepared
By force, the cement water reducing agent of the workability of concrete can be improved.
The purpose of the present invention can be achieved through the following technical solutions:
Efficient cement water reducing agent is made of the raw material of following parts by weight: 80-90 parts of polycarboxylate water-reducer, defoaming agent
0.16-0.18 parts, 1-1.2 parts of viscosity modifier, 0.8-0.9 parts of modified lignin resin;
The defoaming agent is nonionic polyether defoaming agent;
Efficient cement water reducing agent is made of following steps:
Step S1, the preparation of polycarboxylate water-reducer
1) in the four-hole boiling flask equipped with thermometer, blender, reflux condensing tube and heating device, diethylene glycol (DEG) is sequentially added
Amine, deionized water, the concentrated sulfuric acid, sodium sulphate;
2) when temperature reaches 90 DEG C, maleic anhydride is repeatedly added portionwise on a small quantity, reacts 3h, obtains reactive intermediate;Its
In, the ratio between amount of substance of maleic anhydride and diglycolamine is 1.1:1, monomer concentration 10%, the use of the concentrated sulfuric acid and sodium sulphate
Amount is respectively the 1.2% and 1% of monomer mass, and the concentrated sulfuric acid is the sulfuric acid that mass fraction is 98%;
3) in the glass reaction container equipped with water-bath, thermometer, blender and reflux condensing tube, deionized water is added
It with isopentene group polyoxyethylene ether, heats while stirring to solid material and is completely dissolved, adjust the temperature to 60 DEG C, in 60 DEG C of constant temperature
Under the conditions of initiator ammonium persulfate is successively added dropwise respectively in 3h, acrylic acid, methylpropene sodium sulfonate and reactive intermediate carry out
Copolymerization after being added dropwise, continues to keep the temperature 50-60min;
Wherein, the additional amount of deionized water is 11-12 times of isopentene group polyoxyethylene ether quality, isopentene group polyoxy second
The ratio between amount of substance of alkene ether, acrylic acid, methylpropene sodium sulfonate, reactive intermediate is 1.0:2.0:0.5:3.2, ammonium persulfate
Dosage be monomer mass 1.1%;
4) sodium hydroxide solution for being after reaction, 30% with mass fraction adjusts pH value to 6.9-7.2, obtains poly- carboxylic
Sour water-reducing agent;
Step S2, defoaming agent, viscosity modifier and lignin are mixed in polycarboxylate water-reducer, is uniformly mixed, made
Obtain the efficient cement water reducing agent.
Further, the viscosity modifier is prepared by the following method:
(1) sodium p styrene sulfonate and diacetone acrylamide are dissolved in a certain amount of deionized water, obtain mixing molten
Liquid is added the NaOH solution that mass fraction is 28% and adjusts the pH value of mixed solution to 7.5-8;
(2) a certain amount of initiator is added in mixed solution, is put into 60 DEG C of water bath with thermostatic control, is passed through nitrogen thereto
Lower reaction 4h is slowly stirred in 60r/min after 30-35min;
(3) after reaction, deionized water is added, obtains the viscosity modifier;
Wherein, reaction monomers concentration is 10%, and the mass ratio of sodium styrene sulfonate and diacetone acrylamide is 7:3, is drawn
Hair agent is sodium peroxydisulfate, and initiator amount is the 0.5% of monomer gross mass.
Further, the modified lignin resin is prepared by the following method:
(1) rice straw lignin is placed in 60 DEG C of vacuum ovens dry 16h, it is spare;
(2) lignin after weighing drying is dissolved in the sodium hydroxide that mass fraction is 28% by amount under strong stirring
In solution, it is then slowly added to the pyroracemic aldehyde solution that mass fraction is 20% at room temperature, wherein after pyroracemic aldehyde solution and drying
The ratio between the dosage of lignin be 5mL:3g, regulation system pH value to 11.8-12 reacts 4h at 60 DEG C, and product is cooled to room
Temperature;
(3) 1molL is used-1Hydrochloric acid solution the lignin in above-mentioned product is precipitated, then be washed with distilled water to filtrate
For neutrality, dry 22-24h, obtains modified lignin resin in 60 DEG C of vacuum ovens.
The preparation method of efficient cement water reducing agent, includes the following steps:
Step S1, the preparation of polycarboxylate water-reducer:
1) in the four-hole boiling flask equipped with thermometer, blender, reflux condensing tube and heating device, diethylene glycol (DEG) is sequentially added
Amine, deionized water, the concentrated sulfuric acid, sodium sulphate;
2) when temperature reaches 90 DEG C, maleic anhydride is repeatedly added portionwise on a small quantity, reacts 3h, obtains reactive intermediate;Its
In, the ratio between amount of substance of maleic anhydride and diglycolamine is 1.1:1, monomer concentration 10%, the use of the concentrated sulfuric acid and sodium sulphate
Amount is respectively the 1.2% and 1% of monomer mass, and the concentrated sulfuric acid is the sulfuric acid that mass fraction is 98%;
3) in the glass reaction container equipped with water-bath, thermometer, blender and reflux condensing tube, deionized water is added
It with isopentene group polyoxyethylene ether, heats while stirring to solid material and is completely dissolved, adjust the temperature to 60 DEG C, in 60 DEG C of constant temperature
Under the conditions of initiator ammonium persulfate is successively added dropwise respectively in 3h, acrylic acid, methylpropene sodium sulfonate and reactive intermediate carry out
Copolymerization after being added dropwise, continues to keep the temperature 50-60min;
Wherein, the additional amount of deionized water is 11-12 times of isopentene group polyoxyethylene ether quality, isopentene group polyoxy second
The ratio between amount of substance of alkene ether, acrylic acid, methylpropene sodium sulfonate, reactive intermediate is 1.0:2.0:0.5:3.2, ammonium persulfate
Dosage be monomer mass 1.1%;
4) sodium hydroxide solution for being after reaction, 30% with mass fraction adjusts pH value to 6.9-7.2, obtains poly- carboxylic
Sour water-reducing agent;
Step S2, defoaming agent, viscosity modifier and lignin are mixed in polycarboxylate water-reducer, is uniformly mixed, made
Obtain the efficient cement water reducing agent.
Beneficial effects of the present invention:
Cement water reducing agent of the invention is using polycarboxylate water-reducer as main body object, the knot of polycarboxylate water-reducer obtained
Structure main chain contains hydrophilic groups (- COO-), amino (- NH2), hydrophobic grouping ester group (- COOR) and polyether lateral chain;Carboxyl
(- COO-) can generate good absorption and anchorage effect to cement and soil, effectively slow down hydrated cementitious and calcium hydroxide crystallization
It is formed;Polyether lateral chain is stretched in liquid phase and hydrone acts on forming hydration shell, while playing steric hindrance effect with disperse water
Mud particle;Ester group (- COOR) under the high alkalinity environment of hydrated cementitious, occur hydrolyze so that be converted to the strong carboxyl of hydrophily (-
COO-), thus absorption and dispersion cement and mud particles;Short ether side chain and-NH2It is formed respectively with hydrone, polyether lateral chain
Hydrogen bond plays the role of reinforcing steric hindrance;Furthermore carboxyl (- COO-) can be with aluminate positively charged in cement minerals
(C3A, C4AF) generates Electrostatic Absorption;The alkaline environment of hydrated cementitious makes the-NH of water-reducing agent2The positively charged (- NH of group3 +),
It can be acted on silicate (C3S, C2S) negatively charged in cement minerals, the collaboration of these groups on polycarboxylate water-reducer is made
With the opposite lubrication be conducive between its wetting, absorption and particles of aggregates to concrete and concrete particle surface;
The present invention is mixed with quantitative defoaming agent, the working performance and air content of concrete mix in cement water reducing agent
There are certain relationship, suitable bubble is conducive to improve the workability of concrete mix, but air content is excessively high can reduce instead
The fluidity of concrete after mixing defoaming agent, while eliminating air pocket unfavorable to working performance in mixture, still retains
Part is to the advantageous minute bubbles of working performance, therefore the fluidity of mixture increases, and 3h fluidity loss reduces;In mechanical property
Aspect increases the compactness of concrete, also disappears since the incorporation of defoaming agent not only reduces the air content of concrete mix
In addition to the air pocket unfavorable to intensity, the compression strength of concrete can be improved;
The present invention is mixed with modified lignin resin in cement water reducing agent, through the modified lignin of pyroracemic aldehyde, pyroracemic aldehyde
Containing carbonyl and aldehyde radical, hydroxylating can occur under alkaline condition with lignin for aldehyde radical, increase the hydroxyl in lignin
Content is significantly improved by the total hydroxy radical content of modified lignin than before modified, reactivity enhancing, and thermal stability
It is obviously improved;When modified lignin resin is added in concrete, modified lignin resin is as contained by remaining carbohydrate and itself
The groups such as hydroxyl abundant, ehter bond and sulfonic group, have extremely strong inhibiting effect to hydrated cementitious, deferred action can be played;Together
When, modified lignin resin can effectively shield mineral initial stage aquation, be adsorbed in particle surface and form moisture film, hydrated product is avoided to adsorb
High efficiency water reducing agent molecule effectively improves the molecular concentration of high efficiency water reducing agent in liquid phase, improves polycarboxylate water-reducer in concrete
The sensibility of application, to improve the retentivity of mobility, i.e., concrete has preferable function of slump protection;Furthermore modified lignin resin
With certain bleed effect, in concrete can appropriate bleed, improve concrete workability and reduce concrete viscosity, it is right
Concrete has certain function of slump protection;
The present invention is using homemade polycarboxylate water-reducer as main substance, hydrophilic group that homemade polycarboxylate water-reducer contains
Group carboxyl (- COO-), amino (- NH2), that the synergistic effect of hydrophobic grouping ester group (- COOR) and polyether lateral chain is conducive to its is right
Opposite lubrication between the wetting on concrete and concrete particle surface, absorption and particles of aggregates;By the incorporation of defoaming agent, no
The air content that reduced by only concrete mix increases the compactness of concrete, eliminates the air pocket unfavorable to intensity, energy
Enough improve the compression strength of concrete;By the quantitative incorporation of modified lignin resin, modified lignin resin has certain bleed effect,
In concrete can appropriate bleed, improve concrete workability and reduce concrete viscosity, have certain guarantor to concrete and collapse
Performance;Be prepared it is a kind of efficiently, function of slump protection is strong, can improve concrete workability cement water reducing agent, Neng Gouguang
It is general to be applied to building field, there is significant Social benefit and economic benefit.
Specific embodiment
Technical solution of the present invention is clearly and completely described below in conjunction with embodiment, it is clear that described reality
Applying example is only a part of the embodiment of the present invention, instead of all the embodiments.Based on the embodiments of the present invention, this field is general
Logical technical staff all other embodiment obtained without creative efforts belongs to what the present invention protected
Range.
Efficient cement water reducing agent is made of the raw material of following parts by weight: 80-90 parts of polycarboxylate water-reducer, defoaming agent
0.16-0.18 parts, 1-1.2 parts of viscosity modifier, 0.8-0.9 parts of modified lignin resin;
The defoaming agent is nonionic polyether defoaming agent;
There are certain relationship, suitable bubble is conducive to improve concrete the working performance and air content of concrete mix
The workability of mixture, but the excessively high fluidity that can reduce concrete instead of air content after mixing defoaming agent, are eliminating mixture
In unfavorable to working performance air pocket while, still retain part to the advantageous minute bubbles of working performance, therefore mixture
Fluidity increases, and 3h fluidity loss reduces;In terms of mechanical property, mixed since the incorporation of defoaming agent not only reduces concrete
The air content for closing object, increases the compactness of concrete, also eliminates the air pocket unfavorable to intensity, can be improved concrete
Compression strength;
The viscosity modifier is prepared by the following method:
(1) sodium p styrene sulfonate and diacetone acrylamide are dissolved in a certain amount of deionized water, obtain mixing molten
Liquid is added the NaOH solution that mass fraction is 28% and adjusts the pH value of mixed solution to 7.5-8;
(2) a certain amount of initiator is added in mixed solution, is put into 60 DEG C of water bath with thermostatic control, is passed through nitrogen thereto
Lower reaction 4h is slowly stirred in 60r/min after 30-35min;
(3) after reaction, deionized water is added, obtains the viscosity modifier;
Wherein, reaction monomers concentration is 10%, and the mass ratio of sodium p styrene sulfonate and diacetone acrylamide is 7:3,
Initiator is sodium peroxydisulfate, and initiator amount is the 0.5% of monomer gross mass;
Viscosity modifier obtained is the copolymer of sodium p styrene sulfonate and diacetone acrylamide, has branch abundant
Chain structure and excellent absorption property achieve the effect that viscosity reduction by bleed compared to common viscosity modifier, obtained viscous
Degree regulator is the highly branched chain structure by molecule itself, increases it in the adsorption thickness of cement particle surface, reduces surrender
Stress can reduce the viscosity of mixture in the case where not increasing air content;
The modified lignin resin is prepared by the following method:
(1) rice straw lignin is placed in 60 DEG C of vacuum ovens dry 16h, it is spare;
(2) lignin after weighing drying is dissolved in the sodium hydroxide that mass fraction is 28% by amount under strong stirring
In solution, it is then slowly added to the pyroracemic aldehyde solution that mass fraction is 20% at room temperature, wherein after pyroracemic aldehyde solution and drying
The ratio between the dosage of lignin be 5mL:3g, regulation system pH value to 11.8-12 reacts 4h at 60 DEG C, and product is cooled to room
Temperature;
(3) 1molL is used-1Hydrochloric acid solution the lignin in above-mentioned product is precipitated, then be washed with distilled water to filtrate
For neutrality, dry 22-24h, obtains modified lignin resin in 60 DEG C of vacuum ovens;
Through the modified lignin of pyroracemic aldehyde, pyroracemic aldehyde contains carbonyl and aldehyde radical, and aldehyde radical can be with lignin in alkaline item
Hydroxylating occurs under part, increases the hydroxy radical content in lignin, by the total hydroxy radical content of modified lignin than being modified
Before be significantly improved, reactivity enhancing, and thermal stability is obviously improved;Modified lignin resin is added in concrete
When, the groups such as hydroxyl abundant, ehter bond and the sulfonic group of modified lignin resin as remaining carbohydrate and contained by itself, to cement
Aquation has extremely strong inhibiting effect, can play deferred action;Meanwhile modified lignin resin can effectively shield mineral initial stage aquation,
It is adsorbed in particle surface and forms moisture film, avoid hydrated product from adsorbing high efficiency water reducing agent molecule, effectively improve efficient diminishing in liquid phase
The molecular concentration of agent improves the sensibility that polycarboxylate water-reducer is applied in concrete, to improve the retentivity of mobility, i.e.,
Concrete has preferable function of slump protection;Furthermore modified lignin resin have certain bleed effect, in concrete can appropriate bleed,
Improve the workability of concrete and reduce the viscosity of concrete, has certain function of slump protection to concrete;
The preparation method of efficient cement water reducing agent, includes the following steps:
Step S1, the preparation of polycarboxylate water-reducer:
In the four-hole boiling flask equipped with thermometer, blender, reflux condensing tube and heating device, diethylene glycol (DEG) is sequentially added
Amine, deionized water, the concentrated sulfuric acid, sodium sulphate;
When temperature reaches 90 DEG C, maleic anhydride is repeatedly added portionwise on a small quantity, reacts 3h, obtains reactive intermediate;Wherein,
The dosage of n (maleic anhydride): n (diglycolamine)=1.1:1, monomer concentration 10%, the concentrated sulfuric acid and sodium sulphate is respectively monomer
The 1.2% of quality and 1%, the concentrated sulfuric acid is the sulfuric acid that mass fraction is 98%;(reactive intermediate polymerize in aqueous free radical
Ester group and amino are introduced in journey)
Equipped with water-bath, thermometer, blender and reflux condensing tube glass reaction container in, be added deionized water and
Isopentene group polyoxyethylene ether, heats while stirring to solid material and is completely dissolved, and adjusts the temperature to 60 DEG C, in 60 DEG C of constant temperature items
Initiator ammonium persulfate, acrylic acid, methylpropene sodium sulfonate and reactive intermediate is successively added dropwise under part respectively in 3h to be total to
It is poly-, after being added dropwise, continue to keep the temperature 50-60min;Wherein, the additional amount of deionized water is isopentene group polyoxyethylene ether quality
11-12 times, n (isopentene group polyoxyethylene ether): n (acrylic acid): n (methylpropene sodium sulfonate): n (reactive intermediate)=
1.0:2.0:0.5:3.2, the dosage of ammonium persulfate are the 1.1% of monomer mass;
After reaction, the sodium hydroxide solution for being 30% with mass fraction adjusts pH value to 6.9-7.2, obtains polycarboxylic acids
Water-reducing agent;
The structural backbone of polycarboxylate water-reducer obtained contains hydrophilic groups (- COO-), amino (- NH2), hydrophobic group
Group ester group (- COOR) and polyether lateral chain;Carboxyl (- COO-) can generate good absorption and anchorage effect to cement and soil,
Effectively slow down hydrated cementitious and calcium hydroxide crystallizes to be formed;Polyether lateral chain is stretched in liquid phase and hydrone acts on forming aquation
Film, while steric hindrance effect is played with disperse cement particles;Ester group (- COOR) is under the high alkalinity environment of hydrated cementitious, hair
Unboiled water solution is converted to the strong carboxyl (- COO-) of hydrophily in turn, thus absorption and dispersion cement and mud particles;Short ether side chain
With-NH2Hydrogen bond is formed with hydrone, polyether lateral chain respectively, plays the role of reinforcing steric hindrance;Furthermore carboxyl (- COO-) can
Electrostatic Absorption is generated with aluminate (C3A, C4AF) positively charged in cement minerals;The alkaline environment of hydrated cementitious makes diminishing
- the NH of agent2The positively charged (- NH of group3 +), it can be acted on silicate (C3S, C2S) negatively charged in cement minerals, polycarboxylic acids
The synergistic effect of these groups on water-reducing agent is conducive to its wetting, absorption and bone to concrete and concrete particle surface
Expect intergranular opposite lubrication;
Step S2, defoaming agent, viscosity modifier and lignin are mixed in polycarboxylate water-reducer, is uniformly mixed, made
Obtain the efficient cement water reducing agent.
When in use, it is 0.2% that water-reducing agent rolls over solid volume to the efficient cement water reducing agent.
Embodiment 1
Efficient cement water reducing agent is made of the raw material of following parts by weight: 80 parts of polycarboxylate water-reducer, defoaming agent 0.16
Part, 1 part of viscosity modifier, 0.8 part of modified lignin resin;
The preparation method of efficient cement water reducing agent, includes the following steps:
Step S1, the preparation of polycarboxylate water-reducer:
1) in the four-hole boiling flask equipped with thermometer, blender, reflux condensing tube and heating device, diethylene glycol (DEG) is sequentially added
Amine, deionized water, the concentrated sulfuric acid, sodium sulphate;
2) when temperature reaches 90 DEG C, maleic anhydride is repeatedly added portionwise on a small quantity, reacts 3h, obtains reactive intermediate;Its
In, n (maleic anhydride): n (diglycolamine)=1.1:1, monomer concentration 10%, the dosage respectively list of the concentrated sulfuric acid and sodium sulphate
The 1.2% of weight and 1%, the concentrated sulfuric acid is the sulfuric acid that mass fraction is 98%;
3) in the glass reaction container equipped with water-bath, thermometer, blender and reflux condensing tube, deionized water is added
It with isopentene group polyoxyethylene ether, heats while stirring to solid material and is completely dissolved, adjust the temperature to 60 DEG C, in 60 DEG C of constant temperature
Under the conditions of initiator ammonium persulfate is successively added dropwise respectively in 3h, acrylic acid, methylpropene sodium sulfonate and reactive intermediate carry out
Copolymerization after being added dropwise, continues to keep the temperature 50min;Wherein, the additional amount of deionized water is isopentene group polyoxyethylene ether quality
11 times, n (isopentene group polyoxyethylene ether): n (acrylic acid): n (methylpropene sodium sulfonate): n (reactive intermediate)=1.0:
2.0:0.5:3.2, the dosage of ammonium persulfate are the 1.1% of monomer mass;
4) sodium hydroxide solution for being after reaction, 30% with mass fraction adjusts pH value to 6.9-7.2, obtains poly- carboxylic
Sour water-reducing agent;
Step S2, defoaming agent, viscosity modifier and lignin are mixed in polycarboxylate water-reducer, is uniformly mixed, made
Obtain the efficient cement water reducing agent.
Embodiment 2
Efficient cement water reducing agent is made of the raw material of following parts by weight: 85 parts of polycarboxylate water-reducer, defoaming agent 0.17
Part, 1.1 parts of viscosity modifier, 0.85 part of modified lignin resin;
The preparation method of efficient cement water reducing agent, includes the following steps:
Step S1, the preparation of polycarboxylate water-reducer:
1) in the four-hole boiling flask equipped with thermometer, blender, reflux condensing tube and heating device, diethylene glycol (DEG) is sequentially added
Amine, deionized water, the concentrated sulfuric acid, sodium sulphate;
2) when temperature reaches 90 DEG C, maleic anhydride is repeatedly added portionwise on a small quantity, reacts 3h, obtains reactive intermediate;Its
In, n (maleic anhydride): n (diglycolamine)=1.1:1, monomer concentration 10%, the dosage respectively list of the concentrated sulfuric acid and sodium sulphate
The 1.2% of weight and 1%, the concentrated sulfuric acid is the sulfuric acid that mass fraction is 98%;
3) in the glass reaction container equipped with water-bath, thermometer, blender and reflux condensing tube, deionized water is added
It with isopentene group polyoxyethylene ether, heats while stirring to solid material and is completely dissolved, adjust the temperature to 60 DEG C, in 60 DEG C of constant temperature
Under the conditions of initiator ammonium persulfate is successively added dropwise respectively in 3h, acrylic acid, methylpropene sodium sulfonate and reactive intermediate carry out
Copolymerization after being added dropwise, continues to keep the temperature 55min;Wherein, the additional amount of deionized water is isopentene group polyoxyethylene ether quality
11.5 times, n (isopentene group polyoxyethylene ether): n (acrylic acid): n (methylpropene sodium sulfonate): n (reactive intermediate)=1.0:
2.0:0.5:3.2, the dosage of ammonium persulfate are the 1.1% of monomer mass;
4) sodium hydroxide solution for being after reaction, 30% with mass fraction adjusts pH value to 6.9-7.2, obtains poly- carboxylic
Sour water-reducing agent;
Step S2, defoaming agent, viscosity modifier and lignin are mixed in polycarboxylate water-reducer, is uniformly mixed, made
Obtain the efficient cement water reducing agent.
Embodiment 3
Efficient cement water reducing agent is made of the raw material of following parts by weight: 90 parts of polycarboxylate water-reducer, defoaming agent 0.18
Part, 1.2 parts of viscosity modifier, 0.9 part of modified lignin resin;
The preparation method of efficient cement water reducing agent, includes the following steps:
Step S1, the preparation of polycarboxylate water-reducer:
1) in the four-hole boiling flask equipped with thermometer, blender, reflux condensing tube and heating device, diethylene glycol (DEG) is sequentially added
Amine, deionized water, the concentrated sulfuric acid, sodium sulphate;
2) when temperature reaches 90 DEG C, maleic anhydride is repeatedly added portionwise on a small quantity, reacts 3h, obtains reactive intermediate;Its
In, n (maleic anhydride): n (diglycolamine)=1.1:1, monomer concentration 10%, the dosage respectively list of the concentrated sulfuric acid and sodium sulphate
The 1.2% of weight and 1%, the concentrated sulfuric acid is the sulfuric acid that mass fraction is 98%;
3) in the glass reaction container equipped with water-bath, thermometer, blender and reflux condensing tube, deionized water is added
It with isopentene group polyoxyethylene ether, heats while stirring to solid material and is completely dissolved, adjust the temperature to 60 DEG C, in 60 DEG C of constant temperature
Under the conditions of initiator ammonium persulfate is successively added dropwise respectively in 3h, acrylic acid, methylpropene sodium sulfonate and reactive intermediate carry out
Copolymerization after being added dropwise, continues to keep the temperature 60min;Wherein, the additional amount of deionized water is isopentene group polyoxyethylene ether quality
12 times, n (isopentene group polyoxyethylene ether): n (acrylic acid): n (methylpropene sodium sulfonate): n (reactive intermediate)=1.0:
2.0:0.5:3.2, the dosage of ammonium persulfate are the 1.1% of monomer mass;
4) sodium hydroxide solution for being after reaction, 30% with mass fraction adjusts pH value to 6.9-7.2, obtains poly- carboxylic
Sour water-reducing agent;
Step S2, defoaming agent, viscosity modifier and lignin are mixed in polycarboxylate water-reducer, is uniformly mixed, made
Obtain the efficient cement water reducing agent.
Comparative example
As a comparison case with commercially available polycarboxylate water-reducer.
It is 0.2% that embodiment 1-3 and comparative example, which are rolled over solid volume according to water-reducing agent in concrete, does performance measurement:
The working performance and mechanical property of concrete mix respectively according to GB/T 50080-2002, " mix by normal concrete
Close physical performance test method standard " and GB/T 50081-2002 " standard for test methods of mechanical properties of ordinary concrete " progress,
Test result is as follows shown in table:
It is found that mix the water-reducing agent that is prepared of embodiment 1-3 in concrete, initial flow degree reach 593mm with
On, 3h fluidity loss is 15mm, illustrates that the cement water reducing agent of the invention being prepared can increase the workability of concrete
And fluidity;Air content is 1.6% hereinafter, the compression strength of 7d reaches 37.3-37.4MPa, and the compression strength after 28d reaches
49.5-49.8MPa, time of decaying are 3.8-3.9s, and the water-reducing agent for illustrating that the present invention is prepared can have strong slump retaining
Energy and compression strength, obtained mechanical performance of concrete are good.
Present invention disclosed above preferred embodiment is only intended to help to illustrate the present invention.There is no detailed for preferred embodiment
All details are described, are not limited the invention to the specific embodiments described.Obviously, according to the content of this specification,
It can make many modifications and variations.These embodiments are chosen and specifically described to this specification, is in order to better explain the present invention
Principle and practical application, so that skilled artisan be enable to better understand and utilize the present invention.The present invention is only
It is limited by claims and its full scope and equivalent.