Waterproof polymer cement mortar and preparation method thereof

Abstract

The invention relates to waterproof polymer cement mortar and a preparation method thereof, and belongs to the technical field of building materials, the waterproof polymer cement mortar comprises the following components by weight: 100 parts of Portland cement, 100-150 parts of aggregate, 15-25 parts of epoxy resin emulsion, 1-3 parts of an auxiliary agent, and 40-80 parts of water. The epoxy resin emulsion comprises epoxy resin, a modified curing agent and water, and the modified curing agent comprises the following raw materials: trimethylolpropane triglycidyl ether, polyether amine and triethylene tetramine. The modified curing agent prepared from the trimethylolpropane triglycidyl ether, the polyether amine and the triethylene tetramine can form the epoxy resin emulsion without additionally adding an emulsifier, so that the performance reduction caused by the compatibility problem of the emulsifier and cement is avoided, and meanwhile, the performance of the epoxy resin emulsion is improved. A trimethylolpropane skeleton in the trimethylolpropane triglycidyl ether can provide higher crosslinking density for the epoxy resin, and the bonding strength of the mortar is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of building materials, and particularly relates to a waterproof polymer cement mortar and a preparation method thereof. BACKGROUND

[0002] The polymer waterproof mortar is a waterproof material prepared from water-based polymer powder or latex, ordinary Portland cement and special aggregate as main components, and various modified additives.

[0003] Since the polymer is usually introduced into the cement-based material in the form of an emulsion, the use of emulsifiers is inevitable. The emulsifiers can make the polymer particles uniformly dispersed in water to form a stable emulsion system by reducing the interfacial tension, which can make the polymer uniformly distributed in the cement paste, avoid agglomeration, and thus effectively play the roles of toughening, waterproofing and bonding enhancement. However, the traditional emulsifiers (such as anionic surfactants) contain sulfate, chloride and other components, which can interfere with the hydration reaction of minerals in cement, affect the crystalline morphology and rate of hydration products, and cause the performance to decrease. SUMMARY

[0004] In view of the above, in order to overcome at least part of the defects of the prior art, the present application provides a waterproof polymer cement mortar and a preparation method thereof.

[0005] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows: The present application provides a waterproof polymer cement mortar, which comprises the following components by weight: 100 parts of Portland cement, 100-150 parts of aggregate, 15-25 parts of epoxy resin emulsion, 1-3 parts of additive and 40-80 parts of water, wherein the epoxy resin emulsion comprises epoxy resin, modified curing agent and water, and the raw materials of the modified curing agent comprise trimethylolpropane triglycidyl ether, polyether amine and triethylenetetramine.

[0006] In some embodiments of the present application, the mass ratio of epoxy resin, modified curing agent and water in the epoxy resin emulsion is 10:(1-3):(4-6).

[0007] In some embodiments of the present application, the polyether amine is polyether amine D230 or polyether amine D400.

[0008] In some embodiments of the present application, the aggregate is medium sand, the particle size of the medium sand is <5 mm, and the clay content is <3%.

[0009] In some embodiments of the present application, the auxiliary agent comprises a water reducing agent and a defoaming agent, the water reducing agent is one of polycarboxylic acid water reducing agent, melamine water reducing agent and naphthalene water reducing agent, and the defoaming agent is a silicone defoaming agent.

[0010] The second aspect of the present application provides a preparation method of waterproof polymer cement mortar, comprising: After the silicate cement, aggregate and auxiliary agent are fully mixed, water and epoxy resin emulsion are added, and stirring is performed for 3-5 min to obtain the cement mortar.

[0011] In some embodiments of the present application, the preparation method of the epoxy resin emulsion comprises: After the epoxy resin and the modified curing agent are mixed, stirring is performed for 0.5-1 min, water is added, and stirring is continued for 1-2 min to obtain the epoxy resin emulsion.

[0012] In some embodiments of the present application, the preparation method of the modified curing agent comprises: The intermediate product is obtained by adding trimethylolpropane triglycidyl ether and polyether amine into a reaction kettle, heating and warming to 60-80 DEG C under nitrogen atmosphere, and reacting for 2-4 h; The modified curing agent is obtained by adding the intermediate product and triethylenetetramine into a reaction kettle, heating and warming to 60-80 DEG C under nitrogen atmosphere, and reacting for 1-3 h.

[0013] In some embodiments of the present application, the mass ratio of the trimethylolpropane triglycidyl ether to the polyether amine is 1:1.1-1.3, and the mass ratio of the intermediate product to the triethylenetetramine is 1:2-3.

[0014] The present application has the following beneficial effects: The modified curing agent prepared by using trimethylolpropane triglycidyl ether, polyether amine and triethylenetetramine can form the epoxy resin emulsion without additional emulsifier, avoids the performance decline caused by the compatibility problem of the emulsifier and cement, and the trimethylolpropane skeleton in the trimethylolpropane triglycidyl ether can provide higher crosslinking density for the epoxy resin, thereby improving the bonding strength of the mortar. DETAILED DESCRIPTION

[0015] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0016] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Also, any method and material similar or equivalent to those described herein can be used in the practice of the present application. The description herein of preferred methods and materials is intended to be only exemplary and is not intended to limit the scope of the application.

[0017] The endpoints of the ranges and any values described herein are not limited to the precise values stated. The ranges and values should be construed to be roughly about the ranges or values. For ranges, the endpoints are included and the ranges are inclusive of the values between the endpoints. For values, the values between the endpoints are included.

[0018] In order to solve the problems existing in the prior art mentioned in the background, the first aspect of the embodiments of the present application provides a waterproof polymer cement mortar, which comprises the following components in parts by weight: 100 parts of Portland cement, 100-150 parts of aggregate, 15-25 parts of epoxy resin emulsion, 1-3 parts of additive, and 40-80 parts of water. In the components, the Portland cement generates hydration reaction after being contacted with water to generate products such as hydrated calcium silicate and ettringite, thereby forming a rigid three-dimensional network structure to provide the base strength and bearing capacity of the mortar. The aggregate acts as a rigid skeleton to bear external load, thereby significantly improving the compressive strength and wear resistance of the mortar. Meanwhile, the aggregate can inhibit the shrinkage of the cement matrix through the skeleton restraint effect to reduce the risk of cracking. The epoxy resin emulsion can form a film in the cement paste to form an organic-inorganic interpenetrating network, thereby enhancing the flexibility of the mortar. In addition, the polymer film formed by the epoxy resin emulsion can penetrate into the micropores of the base layer to enhance the interfacial adhesion of the mortar through physical anchoring and chemical bonding.

[0019] The epoxy resin emulsion comprises epoxy resin, modified curing agent, and water, and the raw materials of the modified curing agent comprise trimethylolpropane triglycidyl ether, polyether amine, and triethylene tetramine. The triethylene tetramine is a fatty amine curing agent of polyethylene polyamine, which has the advantages of low viscosity, high maturity, and many active sites. Therefore, the triethylene tetramine is selected as the main reaction active component of the curing agent. The trimethylolpropane triglycidyl ether is a trifunctional epoxy monomer containing three epoxy groups, and the trimethylolpropane skeleton in the molecule can provide higher crosslinking density for the epoxy resin. The polyether segment of the polyether amine has strong hydrophilicity and belongs to a non-ionic water-soluble segment, which does not ionize in an aqueous solution and is less affected by strong electrolytes (calcium and magnesium ions) and strong acids and strong bases. Therefore, the polyether amine can maintain stable water solubility in the cement hydration environment, thereby endowing the modified curing agent with stable self-emulsifying property without the need for additional emulsifiers.

[0020] In some embodiments of the present application, the mass ratio of the epoxy resin, the modified curing agent and water in the epoxy resin emulsion is 10:(1-3):(4-6). If the content of the modified curing agent in the epoxy resin emulsion is too low, the stability of the epoxy resin emulsion is poor, and the curing effect of the epoxy resin is worse. If the content of the modified curing agent is too high, the viscosity of the epoxy resin emulsion is too large. Therefore, the mass ratio of the epoxy resin, the modified curing agent and water is set to 10:(1-3):(4-6).

[0021] In some embodiments of the present application, the polyetheramine is polyetheramine D230 or polyetheramine D400. Both polyetheramine D230 and polyetheramine D400 are bifunctional polyetheramines, containing ether bonds and terminal amino groups in the molecular structure, and have flexibility and reactivity. The molecular weight of polyetheramine D230 is about 230, and it has a higher amine value, a lower equivalent of active hydrogen, a faster curing reaction speed, a larger hardness after curing, a molecular weight of polyetheramine D400 is about 400, and it has a slower curing speed and better flexibility after curing.

[0022] In some embodiments of the present application, the aggregate is medium sand, the particle size of the medium sand is <5mm, and the clay content is <3%. The gradation of the aggregate directly affects the density and porosity. The particle size distribution of the medium sand is between that of fine sand and coarse sand, which can more evenly fill the voids between the cement particles and form a dense mortar structure. When the sand particle size exceeds 5mm, the shrinkage cracks at the interface between the mortar and the aggregate increase significantly, resulting in a decrease in the impermeability of the mortar. When the clay content is too high (more than 3%), the soil particles (such as clay minerals) will wrap the cement particles, hindering the hydration reaction, and reducing the strength and durability of the mortar.

[0023] In some embodiments of the present application, the additives include water reducing agents and defoaming agents. The water reducing agent is one of polycarboxylic acid water reducing agent, melamine water reducing agent and naphthalene series water reducing agent. The defoaming agent is an organic silicon defoaming agent. The water reducing agent can reduce the water-cement ratio of concrete or mortar, achieve the following functions: reduce water consumption while maintaining or increasing the fluidity and plasticity of the paste, facilitate construction pouring, reduce the pores formed by water evaporation, improve the compressive strength and impermeability, inhibit shrinkage cracks, reduce the penetration of erosive media, and prolong the service life of the structure. The defoaming agent can reduce the foam generated during construction due to stirring or chemical action, and avoid structural looseness caused by residual air bubbles.

[0024] The second aspect of the embodiments of the present application provides a preparation method of waterproof polymer cement mortar, which comprises: mixing silicate cement, aggregate and additives sufficiently, then adding water and epoxy resin emulsion, stirring for 3-5 min to obtain cement mortar. The mixing of the silicate cement, the aggregate and the additives can be carried out by using a stirrer, the stirring speed can be 50-60 r / min, and the stirring time can be 5-8 min, so that the silicate cement, the aggregate and the additives can be mixed sufficiently.

[0025] In some embodiments of the present application, the preparation method of the epoxy resin emulsion comprises: mixing the epoxy resin and the modified curing agent, stirring for 0.5-1 min, adding water, and continuing to stir for 1-2 min to obtain the epoxy resin emulsion. In the mixing of the epoxy resin and the modified curing agent, a high-speed mixer can be used, and the stirring speed is 1500-3000 r / min, so that the epoxy resin and the modified curing agent can be fully emulsified.

[0026] In some embodiments of the present application, the preparation method of the modified curing agent comprises: taking trimethylolpropane triglycidyl ether and polyether amine into a reaction kettle, heating and warming to 60-80℃ under nitrogen atmosphere, and reacting for 2-4 h to obtain an intermediate product; taking the intermediate product and triethylenetetramine into the reaction kettle, heating and warming to 60-80℃ under nitrogen atmosphere, and reacting for 1-3 h to obtain the modified curing agent. Trimethylolpropane triglycidyl ether is used as a connecting core, so that the amino group of the polyether amine reacts with the epoxy group of the trimethylolpropane triglycidyl ether to generate the intermediate product, and then the amino group of the triethylenetetramine further reacts with the remaining epoxy group in the intermediate product to generate the modified curing agent. The modified curing agent contains three main characteristic segments: the trimethylolpropane in the trimethylolpropane triglycidyl ether provides a skeleton, the polyether segment of the polyether amine provides good and stable water solubility, and the fatty amine segment of the triethylenetetramine, in which the primary and secondary fatty amines have water solubility and strong reactivity, provides main curing capacity.

[0027] In some embodiments of the present application, the mass ratio of the trimethylolpropane triglycidyl ether to the polyether amine is 1:1.1-1.3, and the mass ratio of the intermediate product to the triethylenetetramine is 1:2-3. By setting the mass ratio of the trimethylolpropane triglycidyl ether to the polyether amine to 1:1.1-1.3, sufficient epoxy groups can be reserved for subsequent reactions, and by setting the mass ratio of the intermediate product to the triethylenetetramine to 1:2-3, the epoxy groups of the intermediate product can be completely reacted.

[0028] The present application is further described below in the manner of specific embodiments.

[0029] In the following examples, the experimental methods are all conventional methods unless otherwise specified; and the experimental materials used in the following examples are all purchased from commercial channels unless otherwise specified.

[0030] In the following examples, the aggregate is medium sand, the particle size of the medium sand is <5 mm, the clay content is <3%, the additives include water reducing agent and defoaming agent, and the mass ratio of the water reducing agent to the defoaming agent is 1:1.

[0031] Example 1 Take trimethylolpropane triglycidyl ether and polyether amine D230 into the reaction kettle, the mass ratio of trimethylolpropane triglycidyl ether to polyether amine is 1:1.1, heat to 60℃ under nitrogen atmosphere, react for 2h, get intermediate product.

[0032] Take the intermediate product and triethylene tetramine into the reaction kettle, the mass ratio of the intermediate product to triethylene tetramine is 1:2, heat to 60℃ under nitrogen atmosphere, react for 1h, get modified curing agent.

[0033] Mix the epoxy resin and the modified curing agent, stir for 0.5min, add water, continue to stir for 1min, the mass ratio of epoxy resin, modified curing agent and water is 10:1:4, get epoxy resin emulsion.

[0034] Mix 100 parts of Portland cement, 100 parts of aggregate and 1 part of auxiliary agent thoroughly, add 40 parts of water and 15 parts of epoxy resin emulsion, stir for 3min, get cement mortar.

[0035] Example 2 Take trimethylolpropane triglycidyl ether and polyether amine D400 into the reaction kettle, the mass ratio of trimethylolpropane triglycidyl ether to polyether amine is 1:1.3, heat to 80℃ under nitrogen atmosphere, react for 4h, get intermediate product.

[0036] Take the intermediate product and triethylene tetramine into the reaction kettle, the mass ratio of the intermediate product to triethylene tetramine is 1:3, heat to 80℃ under nitrogen atmosphere, react for 3h, get modified curing agent.

[0037] Mix the epoxy resin and the modified curing agent, stir for 1min, add water, continue to stir for 2min, the mass ratio of epoxy resin, modified curing agent and water is 10:3:6, get epoxy resin emulsion.

[0038] Mix 100 parts of Portland cement, 150 parts of aggregate and 3 parts of auxiliary agent thoroughly, add 80 parts of water and 25 parts of epoxy resin emulsion, stir for 5min, get cement mortar.

[0039] Example 3 Consistent with example 1, the difference is that in the epoxy resin emulsion, the mass ratio of epoxy resin, modified curing agent and water is 10:2:4.

[0040] Example 4 Consistent with example 1, the difference is that in the epoxy resin emulsion, the mass ratio of epoxy resin, modified curing agent and water is 10:3:4.

[0041] Example 5 Consistent with Example 1, the difference is that after 100 parts of Portland cement, 100 parts of aggregate and 1 part of additive are mixed thoroughly, 40 parts of water and 20 parts of epoxy resin emulsion are added, and stirred for 3 min to obtain cement mortar.

[0042] Example 6 Consistent with Example 1, the difference is that after 100 parts of Portland cement, 100 parts of aggregate and 1 part of additive are mixed thoroughly, 40 parts of water and 25 parts of epoxy resin emulsion are added, and stirred for 3 min to obtain cement mortar.

[0043] Comparative Example 1 Consistent with Example 1, the difference is that in the waterproof polymer cement mortar, a commercially available butyl benzene emulsion is used instead of the epoxy resin emulsion.

[0044] Comparative Example 2 Consistent with Example 1, the difference is that in the epoxy resin emulsion, triethylene tetramine is used instead of the modified curing agent, and a cationic surfactant is added as an emulsifying agent.

[0045] Performance tests are carried out on Examples 1-6 and Comparative Examples 1 and 2, and the test contents are as follows: Adhesion test: According to the standard JC / T 985-2017 “Cement-based self-leveling mortar for base”, the base material is a concrete plate, the forming frame is placed on the forming surface of the concrete bottom plate, the prepared sample is poured into the forming frame, the surface is smoothed, and after 24 hours, the sample is demolded, each group of test pieces is 10, the sample after demolding is placed under standard test conditions until the 27-day age, the surface of the sample is polished with sandpaper to ensure that the bonding surface is clean, the high-strength adhesive is used to fix the pull joint on the forming surface of the sample, and the sample is further placed under standard conditions for 24 hours. A tensile testing machine is used for loading test, and the tensile speed is (5±1) mm / min. The bonding strength calculation formula is as follows: P=F / A, P is the bonding strength (Mpa), F is the failure load (N), and A is the bonding area (mm 2 ).

[0046] Compressive strength test: The mixed sample is prepared into a 40mm×40mm×160mm prism, and after demolding, the sample is cured in an environment with a temperature of (20±3) °C and a humidity of ≥90% for 28 days. After curing, the surface of the sample is wiped, the sample is placed in the center of the lower plate of the pressure testing machine, the pressure surface is ensured to be perpendicular to the forming surface, and the sample is uniformly loaded at a speed of 0.3-0.5 MPa / s. The failure load is recorded. The compressive strength (f c ) is calculated according to the following formula: f c =F / A, F is the failure load (N), and A is the pressure area (mm 2 ).

[0047] Flexural strength test: The mixed sample was prepared into a 40mmx40mmx160mm prism. After demolding, the test piece was cured in an environment with a temperature of (20±3) °C and a humidity of ≥90% for 28 days. After curing, the surface of the test piece was wiped, and the test piece was placed on the support of the flexural test machine with the molding side as the bearing surface. The span was 100mm, and the uniform speed was loaded at a rate of 50±10N / s until the test piece was broken. The fracture surface was located between the two loading points, which was effective, otherwise the test was invalid and needed to be redone. The flexural strength (R f ) was calculated according to the following formula: R f =(1.5FL) / b 3 , F is the failure load (N), L is the span (mm), and b is the width of the test piece (mm).

[0048] The test results are shown in Table 1.

[0049] Table 1

[0050] Referring to the adhesion test results in Table 1, the bonding strength of Comparative Example 1 is significantly lower than that of Example 1, indicating that the bonding strength of the epoxy resin emulsion of Example 1 is better than that of the commercially available butyl benzene emulsion. The bonding strength of Comparative Example 2 is significantly lower than that of Example 1, and the use of a modified curing agent can improve the bonding strength of the epoxy resin emulsion.

[0051] Referring to the compressive strength test results in Table 1, the compressive strength of Comparative Example 1 is significantly lower than that of Example 1, indicating that the compressive strength of the epoxy resin emulsion of Example 1 is better than that of the commercially available butyl benzene emulsion. The compressive strength of Comparative Example 2 is significantly lower than that of Example 1, and the use of a modified curing agent can improve the compressive strength of the epoxy resin emulsion.

[0052] Referring to the flexural strength test results in Table 1, the flexural strength of Comparative Example 1 is significantly lower than that of Example 1, indicating that the flexural strength of the epoxy resin emulsion of Example 1 is better than that of the commercially available butyl benzene emulsion. The flexural strength of Comparative Example 2 is significantly lower than that of Example 1, and the use of a modified curing agent can improve the flexural strength of the epoxy resin emulsion.

[0053] In the description of the specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples without contradiction, which should be included in the protection scope of the present application.

[0054] The above embodiments are only used to illustrate the technical solutions of the present application and not limit the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the purpose and scope of the technical solutions of the present application, which should be included in the protection scope of the present application.

Claims

1. A waterproof polymer cement mortar, characterized in that: The invention comprises the following components in parts by weight: 100 parts of Portland cement, 100-150 parts of aggregate, 15-25 parts of epoxy resin emulsion, 1-3 parts of additive and 40-80 parts of water. The epoxy resin emulsion comprises epoxy resin, modified curing agent and water. The raw materials of the modified curing agent comprise trimethylolpropane triglycidyl ether, polyetheramine and triethylenetetramine.

2. The waterproof polymer cement mortar according to claim 1, characterized in that In the epoxy resin emulsion, the mass ratio of epoxy resin, modified curing agent and water is 10:(1-3):(4-6).

3. The waterproof polymer cement mortar according to claim 1, characterized in that The polyetheramine is polyetheramine D230 or polyetheramine D400.

4. The waterproof polymer cement mortar according to claim 1, characterized in that The aggregate is medium sand, the particle size of the medium sand is less than 5mm, and the mud content is less than 3%.

5. The waterproof polymer cement mortar according to claim 1, characterized in that The auxiliary agent includes a water reducer and a defoamer, wherein the water reducer is one of a polycarboxylic acid water reducer, a melamine water reducer and a naphthalene water reducer, and the defoamer is an organosilicon defoamer.

6. The method for preparing the waterproof polymer cement mortar according to any one of claims 1 to 5, characterized in that: include: After fully mixing the Portland cement, aggregate and additives, add water and epoxy resin emulsion and stir for 3-5 minutes to obtain cement mortar.

7. The preparation method according to claim 6, characterized in that The preparation method of the epoxy resin emulsion comprises: After mixing the epoxy resin and the modified curing agent, stir for 0.5-1 min, add water, and continue stirring for 1-2 min to obtain an epoxy resin emulsion.

8. The preparation method according to claim 7, characterized in that The preparation method of the modified curing agent comprises: Add trimethylolpropane triglycidyl ether and polyetheramine into a reaction kettle, heat to 60-80°C under a nitrogen atmosphere, and react for 2-4 hours to obtain an intermediate product; The intermediate product and triethylenetetramine were added to a reaction kettle, heated to 60-80° C. under a nitrogen atmosphere, and reacted for 1-3 hours to obtain a modified curing agent.

9. The preparation method according to claim 8, characterized in that The mass ratio of the trimethylolpropane triglycidyl ether to the polyetheramine is 1:1.1-1.3, and the mass ratio of the intermediate product to triethylenetetramine is 1:2-3.

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