High-strength epoxy mortar suitable for construction in low-temperature environment and preparation method thereof

Abstract

The application relates to the technical field of epoxy mortar, and particularly discloses high-strength epoxy mortar suitable for construction in a low-temperature environment and a preparation method thereof. Technical points of the high-strength epoxy mortar suitable for construction in a low-temperature environment are as follows: the high-strength epoxy mortar suitable for construction in a low-temperature environment comprises A and B components which are separately stored and mixed according to a weight ratio of 12-14:1 during use, the A component comprises the following components in parts by weight: 100-150 parts of epoxy resin, 5-10 parts of a silane coupling agent, 5-10 parts of titanium white, 5-10 parts of a depositions inhibitor, 150-200 parts of quartz sand and 150-200 parts of talcum powder; the B component comprises thiourea modified polyether amine and nonyl phenol, and the weight ratio of the thiourea modified polyether amine to the nonyl phenol is 1:(1.5-3.5). The preparation method is as follows: the A and B components are mixed uniformly and independently packaged. The epoxy mortar provided by the application has the characteristics of good construction performance in a low-temperature environment, and the obtained curing system has excellent mechanical properties.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of epoxy mortar, in particular to high-strength epoxy mortar suitable for construction in a low-temperature environment and a preparation method thereof. BACKGROUND

[0002] Concrete buildings are required to have designed strength and durability, that is, skid resistance, wear resistance, water resistance and corrosion resistance. However, many existing concrete buildings have the following problems: 1. carbonation and cracking of concrete buildings are common; 2. steel reinforcement corrosion caused by erosion of reinforced concrete structures is serious; and 3. loose peeling of concrete surfaces near water.

[0003] At present, epoxy mortar is commonly used to improve the above problems. Epoxy mortar is a concrete surface repair material, which is an epoxy composite material prepared by taking epoxy resin as a main component and adding some auxiliary materials. Epoxy mortar has the characteristics of high strength, good impact and wear resistance, strong adhesion and good water resistance; and traditional epoxy mortar generally needs to be used together with an epoxy resin curing agent.

[0004] As a building material with excellent comprehensive performance, epoxy mortar has been widely used in the repair and reinforcement of buildings. The curing of epoxy mortar is mainly due to the ring-opening polymerization reaction of its epoxy component and curing agent, and the reaction characteristics of each component and the performance of the cured product determine the application scene of the epoxy mortar to a great extent. The use temperature of epoxy mortar is usually above 5℃, and in low temperature, the construction performance of epoxy mortar and the performance of the cured product are difficult to be guaranteed due to the limited system reaction activity and large viscosity. Therefore, in the environment below zero in winter, although there are many relevant literature reports on the technical means to solve the problem of low-temperature curing of epoxy resin, the curing temperature of such reports does not involve subzero, and the mechanical properties of the cured product are generally low.

[0005] At present, thiourea modified amine curing agents are widely used in the field of low-temperature rapid curing of epoxy resins. They not only have great advantages in winter and cold work areas, but also play a very important role in rapid construction occasions. Thiourea can significantly improve the curing activity of the curing agent and epoxy resin, and greatly reduce the curing temperature. The synthesis and application of thiourea modified amine curing agents have always been one of the hot spots in the field of epoxy resins. The thiourea modified binary aliphatic amine, diethylene triamine, triethylene tetramine and phenolic amine curing agent has the characteristics of high activity and fast curing, but the thiourea modified aliphatic amine curing agent has the characteristics of high brittleness and poor mechanical properties after curing with epoxy resin. In addition, during the preparation of low-temperature curing agent, environmentally unfriendly raw materials are easily left, which is harmful to the human body and the environment. SUMMARY

[0006] In order to overcome the above technical problems, the application provides a high-strength epoxy mortar suitable for construction in a low-temperature environment and a preparation method thereof.

[0007] In a first aspect, the application provides a high-strength epoxy mortar suitable for construction in a low-temperature environment, which adopts the following technical solution:

[0008] A high-strength epoxy mortar suitable for construction in a low-temperature environment comprises components A and B which are separately stored and mixed according to a weight ratio of 12-14:1 when used, the component A comprises the following components in parts by weight: epoxy resin 100-150 parts, silane coupling agent 5-10 parts, titanium white powder 5-10 parts, anti-settling agent 5-10 parts, quartz sand 150-200 parts, and talc powder 150-200 parts; and the component B comprises thiourea modified polyether amine and nonyl phenol, and the weight ratio of the thiourea modified polyether amine to the nonyl phenol is 1:(1.5-3.5).

[0009] By adopting the above technical solution, the polyether amine curing agent structure contains long ether bond segments with flexibility, which can overcome the defect of the cured product being too brittle after curing with the epoxy resin, and can also overcome the defect of the raw amine in the thiourea curing agent being too toxic; the curing agent has excellent adhesion and mechanical properties under high-temperature curing conditions, but the curing speed is slow at room temperature, and the mechanical properties also decrease to some extent, especially it is basically difficult to cure the epoxy resin below 0℃. After being modified by the thiourea, the reactivity is greatly improved, and the curing speed is extremely fast, resulting in too short operability time and no sufficient construction window. The nonyl phenol has low reactivity, and the curing speed is slow at low temperature, and when used alone, a complete crosslinking network cannot be formed after long-time curing. In the application, the thiourea modified polyether amine and the nonyl phenol are compounded, the activity of the curing system is moderate, the reaction proceeds stably, the curing speed is controllable, the continuity of the curing process is ensured, the strength of the system after curing is high, and the mechanical properties are excellent.

[0010] Further preferably, the weight ratio of the thiourea modified polyether amine to the nonyl phenol is 1:2.5.

[0011] By adopting the above technical solution, when the weight ratio of the thiourea modified polyether amine to the nonyl phenol is controlled to be 1:2.5, the obtained epoxy mortar has the most suitable operability time, and the curing system has excellent mechanical properties. The thiourea modified polyether amine in the application is obtained by heating and reacting polyether amine D230 with 2 equivalent polyether amine at 110℃, has excellent curing performance, and has a long storage period.

[0012] Further preferably, 10-15 parts by weight of a modifier are further included, and the modifier is selected from at least one of glycerol triglycidyl ether, polypropylene glycol diglycidyl ether, and acetone.

[0013] By adopting the technical scheme, the addition of the modifier can change the viscosity of the mortar system or participate in the cross-linking reaction, thereby improving the construction performance of the mortar system and the mechanical properties of the cured system.

[0014] Further preferably, the modifier is a mixture composed of polypropylene glycol diglycidyl ether and acetone.

[0015] By adopting the technical scheme, acetone is a non-active diluent and belongs to a diluent solvent. It has no active epoxy group in the molecular structure and has no reactivity itself. It only plays a role in viscosity reduction by dilution and is easy to volatilize. During the curing reaction, it is easy to leave voids in the cured body, causing internal defects of the cured body and affecting the mechanical properties. Polypropylene glycol diglycidyl ether is a compound with reactive functional groups. On the one hand, it has good compatibility with epoxy resin, and on the other hand, it can participate in the curing cross-linking reaction and become part of the cross-linking network structure of the resin cement body, thereby improving the toughness and mechanical properties of the cured system. By compounding acetone with polypropylene glycol diglycidyl ether, the mortar system has good toughness and mechanical properties while ensuring low viscosity, i.e., good workability.

[0016] Further preferably, the weight ratio of polypropylene glycol diglycidyl ether to acetone is 1:(0.1-0.25).

[0017] By adopting the technical scheme, the addition of acetone can reduce the viscosity of the mortar system and improve the workability. However, acetone itself does not participate in the curing cross-linking reaction and is easy to volatilize, resulting in voids in the cured system, i.e., excessive addition of acetone can affect the mechanical properties of the cured system. However, in actual application, the inventors found that when the proportion of acetone in the modifier composed of polypropylene glycol diglycidyl ether and acetone is less than 20%, it will not affect the mechanical properties of the cured mortar system. When the proportion of acetone exceeds 20%, the mechanical properties of the cured system become worse and worse as the proportion of acetone becomes larger and larger.

[0018] Further preferably, the silane coupling agent is selected from one of vinyltriethoxysilane, aminopropyltriethoxysilane, and isobutyltriethoxysilane.

[0019] By adopting the technical scheme, the silane coupling agent can be used to improve the adhesion of the organic-inorganic material interface, i.e., to improve the adhesion between the cured epoxy mortar and the building materials.

[0020] Further preferably, the anti-settling agent is selected from one of fumed silica, organic bentonite, and polyolefin wax.

[0021] Further preferably, the particle size of the quartz sand is 20-40 mesh.

[0022] Further preferably, the particle size of the talcum powder is 200-400 mesh.

[0023] Further preferably, the particle size of the titanium dioxide is 200-400 mesh.

[0024] In a second aspect, the application provides a preparation method of high-strength epoxy mortar suitable for construction in a low-temperature environment, which adopts the following technical scheme:

[0025] A preparation method of high-strength epoxy mortar suitable for construction in a low-temperature environment, comprising the following steps:

[0026] Mixing the epoxy resin, silane coupling agent, titanium dioxide, anti-settling agent, quartz sand and talcum powder uniformly to obtain component A, and packaging the output;

[0027] Mixing the thiourea-modified polyether amine and nonyl phenol uniformly to obtain component B, and packaging the output.

[0028] By adopting the above technical scheme, the epoxy mortar preparation method provided by the application is simple to operate, suitable for large-scale production, and when used, components A and B can be mixed uniformly at a certain proportion to obtain a mortar solidification system with excellent mechanical properties.

[0029] In summary, the application has the following beneficial effects:

[0030] (1) The application uses thiourea-modified polyether amine and nonyl phenol for compounding, which can reduce the use amount of thiourea-modified polyether amine, thereby avoiding the possibility of local violent polymerization and ensuring stable reaction; the heat generated by the reaction of thiourea-modified polyether amine and epoxy resin can stimulate the reaction of nonyl phenol and epoxy groups, thereby realizing the continuity of the curing process and ensuring the feasibility of using epoxy mortar in a low-temperature environment;

[0031] (2) The application adds a modifier to change the viscosity of the mortar system or participate in the crosslinking reaction, thereby improving the construction performance of the mortar system in a low-temperature environment and the mechanical properties of the solidification system;

[0032] (3) The modifier of the application is preferably a combination of polypropylene glycol diglycidyl ether and acetone, which ensures that the mortar system has low viscosity, i.e., good construction performance, and still has good toughness and mechanical properties. DETAILED DESCRIPTION

[0033] The application will be further described in detail below in combination with examples.

[0034] In the application, the properties of some raw materials in the examples and comparative examples are as follows:

[0035] The particle size of the quartz sand is 20-40 mesh, the particle size of the talcum powder is 200-400 mesh, and the particle size of the titanium dioxide is 200-400 mesh.

[0036] The epoxy resin is E51 epoxy resin, the silane coupling agent is vinyltriethoxysilane (silane coupling agent YDH-151), and the anti-settling agent is fumed silica, which is purchased from Xuancheng Jingrui New Material Co., Ltd.

[0037] Embodiment

[0038] Embodiment 1

[0039] A high-strength epoxy mortar suitable for construction in a low-temperature environment is prepared by the following steps:

[0040] S1, 100 kg of epoxy mortar, 5 kg of silane coupling agent, 5 kg of titanium dioxide, 5 kg of anti-settling agent, 150 kg of quartz sand, and 150 kg of talcum powder are mixed and stirred uniformly, and then discharged to obtain component A.

[0041] S2, thiourea modified polyether amine and nonyl phenol are mixed in a mass ratio of 1:1.5, stirred uniformly, and then discharged to obtain component B.

[0042] S3, components A and B are mixed in a mass ratio of 12:1, and then stirred uniformly to obtain a high-strength epoxy mortar suitable for construction in a low-temperature environment.

[0043] Embodiment 2

[0044] A high-strength epoxy mortar suitable for construction in a low-temperature environment is prepared by the following steps:

[0045] S1, 125 kg of epoxy mortar, 7.5 kg of silane coupling agent, 7.5 kg of titanium dioxide, 7.5 kg of anti-settling agent, 175 kg of quartz sand, and 175 kg of talcum powder are mixed and stirred uniformly, and then discharged to obtain component A.

[0046] S2, thiourea modified polyether amine and nonyl phenol are mixed in a mass ratio of 1:1.5, stirred uniformly, and then discharged to obtain component B.

[0047] S3, components A and B are mixed in a mass ratio of 13:1, and then stirred uniformly to obtain a high-strength epoxy mortar suitable for construction in a low-temperature environment.

[0048] Embodiment 3

[0049] A high-strength epoxy mortar suitable for construction in a low-temperature environment is prepared by the following steps:

[0050] S1, 150 kg of epoxy mortar, 10 kg of silane coupling agent, 10 kg of titanium dioxide, 10 kg of anti-settling agent, 200 kg of quartz sand, 200 kg of talc powder are mixed, stirred uniformly, discharged, to obtain component A.

[0051] S2, the thiourea modified polyether amine and nonyl phenol are mixed according to the mass ratio 1:1.5, stirred uniformly, discharged, to obtain component B.

[0052] S3, components A and B are mixed according to the mass ratio 14:1, stirred uniformly, to obtain a high-strength epoxy mortar suitable for construction in low-temperature environment.

[0053] Example 4

[0054] A high-strength epoxy mortar suitable for construction in low-temperature environment is prepared by the following steps:

[0055] S1, the same as S1 of Example 1.

[0056] S2, the thiourea modified polyether amine and nonyl phenol are mixed according to the mass ratio 1:2, stirred uniformly, discharged, to obtain component B.

[0057] S3, the same as S3 of Example 1.

[0058] Example 5

[0059] A high-strength epoxy mortar suitable for construction in low-temperature environment is prepared by the following steps:

[0060] S1, the same as S1 of Example 1.

[0061] S2, the thiourea modified polyether amine and nonyl phenol are mixed according to the mass ratio 1:2.5, stirred uniformly, discharged, to obtain component B.

[0062] S3, the same as S3 of Example 1.

[0063] Example 6

[0064] A high-strength epoxy mortar suitable for construction in low-temperature environment is prepared by the following steps:

[0065] S1, the same as S1 of Example 1.

[0066] S2, the thiourea modified polyether amine and nonyl phenol are mixed according to the mass ratio 1:3, stirred uniformly, discharged, to obtain component B.

[0067] S3, the same as S3 of Example 1.

[0068] Example 7

[0069] A high-strength epoxy mortar suitable for construction in low-temperature environments is prepared by the following steps:

[0070] S1, same as S1 of Example 1.

[0071] S2, mix thiourea-modified polyether amine with nonylphenol according to a mass ratio of 1:3.5, stir uniformly, and discharge to obtain component B.

[0072] S3, same as S3 of Example 1.

[0073] Example 8

[0074] A high-strength epoxy mortar suitable for construction in low-temperature environments is prepared by the following steps:

[0075] S1, mix 100 kg of epoxy mortar, 5 kg of silane coupling agent, 5 kg of titanium dioxide, 5 kg of anti-settling agent, 150 kg of quartz sand, 150 kg of talc, and 10 kg of modifier, stir uniformly, and discharge to obtain component A.

[0076] S2, same as S2 of Example 5.

[0077] S3, same as S3 of Example 5.

[0078] The modifier in this example is glycerol triglycidyl ether.

[0079] Example 9

[0080] A high-strength epoxy mortar suitable for construction in low-temperature environments, which is different from Example 8 in that the modifier in this example is polypropylene glycol diglycidyl ether.

[0081] Example 10

[0082] A high-strength epoxy mortar suitable for construction in low-temperature environments, which is different from Example 8 in that the modifier in this example is acetone.

[0083] Example 11

[0084] A high-strength epoxy mortar suitable for construction in low-temperature environments, which is different from Example 8 in that the modifier in this example is a mixture of glycerol triglycidyl ether and polypropylene glycol diglycidyl ether, and the ratio of glycerol triglycidyl ether to polypropylene glycol diglycidyl ether is 1:1.

[0085] Example 12

[0086] A high-strength epoxy mortar suitable for construction in low-temperature environment, which is different from Example 8 in that the modifier in this example is a mixture of glycerol triglycidyl ether and acetone, the ratio of glycerol triglycidyl ether to acetone being 1:0.3.

[0087] Example 13

[0088] A high-strength epoxy mortar suitable for construction in low-temperature environment, which is different from Example 8 in that the modifier in this example is a mixture of polypropylene glycol diglycidyl ether and acetone, the ratio of polypropylene glycol diglycidyl ether to acetone being 1:0.3.

[0089] Example 14

[0090] A high-strength epoxy mortar suitable for construction in low-temperature environment, which is different from Example 8 in that the modifier in this example is a mixture of polypropylene glycol diglycidyl ether and acetone, the ratio of polypropylene glycol diglycidyl ether to acetone being 1:0.25.

[0091] Example 15

[0092] A high-strength epoxy mortar suitable for construction in low-temperature environment, which is different from Example 8 in that the modifier in this example is a mixture of polypropylene glycol diglycidyl ether and acetone, the ratio of polypropylene glycol diglycidyl ether to acetone being 1:0.2.

[0093] Example 16

[0094] A high-strength epoxy mortar suitable for construction in low-temperature environment, which is different from Example 8 in that the modifier in this example is a mixture of polypropylene glycol diglycidyl ether and acetone, the ratio of polypropylene glycol diglycidyl ether to acetone being 1:0.15.

[0095] Example 17

[0096] A high-strength epoxy mortar suitable for construction in low-temperature environment, which is different from Example 8 in that the modifier in this example is a mixture of polypropylene glycol diglycidyl ether and acetone, the ratio of polypropylene glycol diglycidyl ether to acetone being 1:0.1.

[0097] Comparative Example

[0098] Comparative Example 1

[0099] A high-strength epoxy mortar suitable for construction in low-temperature environment, which is prepared by the following steps:

[0100] S1, same as S1 of Example 1.

[0101] S2, polyether amine D230 curing agent is used as component B.

[0102] S3, same as S3 of example 1.

[0103] Comparative example 2

[0104] A high-strength epoxy mortar suitable for construction in low-temperature environments is prepared by the following steps:

[0105] S1, same as S1 of example 1.

[0106] S2, a thiourea-modified polyether amine curing agent is used as component B.

[0107] S3, same as S3 of example 1.

[0108] Comparative example 3

[0109] A high-strength epoxy mortar suitable for construction in low-temperature environments is prepared by the following steps:

[0110] S1, same as S1 of example 1.

[0111] S2, a nonyl phenol curing agent is used as component B.

[0112] S3, same as S3 of example 1.

[0113] Comparative example 4

[0114] A high-strength epoxy mortar suitable for construction in low-temperature environments is prepared by the following steps:

[0115] S1, same as S1 of example 1.

[0116] S2, polyether amine D230 is mixed with nonyl phenol at a mass ratio of 1:1.5, stirred uniformly, discharged, and component B is obtained.

[0117] S3, same as S3 of example 1.

[0118] Comparative example 5

[0119] A high-strength epoxy mortar suitable for construction in low-temperature environments is prepared by the following steps:

[0120] S1, same as S1 of example 1.

[0121] S2, a thiourea-modified polyether amine is mixed with nonyl phenol at a mass ratio of 1:1, stirred uniformly, discharged, and component B is obtained.

[0122] S3, same as S3 of example 1.

[0123] Comparative example 6

[0124] A high-strength epoxy mortar suitable for construction in a low-temperature environment is prepared by the following steps:

[0125] S1, the same as S1 of Example 1.

[0126] S2, mix thiourea modified polyether amine with nonyl phenol according to the mass ratio 1:4, stir uniformly, discharge, get B component.

[0127] S3, the same as S3 of Example 1.

[0128] Performance test

[0129] 1, workable time

[0130] After placing A, B components at-8℃ for 24h, mix A, B components uniformly, make mortar sample, and start timing at the same time, when the viscosity of the sample rises obviously, stop timing, this period of time is the workable time.

[0131] 2, compressive strength

[0132] According to GB / T 17671-2021 "Cement mortar strength test method (ISO)", the temperature control is-8℃ when preparing sample.

[0133] Table 1 test results of examples 1-17, comparative examples 1-6

[0134]

[0135]

[0136] From the test results of examples 1, 4-7, it can be seen that in B component, with the increasing proportion of nonyl phenol, the mortar curing speed is slower and slower, but the strength is higher and higher, when the ratio of thiourea modified polyether amine to nonyl phenol is 1:4, the epoxy mortar has the optimal curing time, i.e. workable time, and higher compressive strength. Comparative examples 1-3 respectively use polyether amine curing agent, nonyl phenol curing agent, polyether amine + nonyl phenol curing agent, which is basically difficult to cure into film or has long curing time in low temperature environment of-8℃. Comparative example 2 uses thiourea modified polyether amine curing agent alone, which has extremely fast curing speed, but the obtained curing system has lower compressive strength.

[0137] This is due to the use of thiourea modified polyether amine alone as curing agent, the system curing too fast, easy to occur local partial polymerization, produce a large number of bubbles, constitute defects, and further affect the system performance; the use of n only phenol alone as curing agent, the reaction activity is too low, it is difficult to form a complete crosslinked network. The use of both can reduce the use of thiourea modified polyether amine, and further avoid the possibility of local polymerization, ensure the reaction to proceed smoothly; and the heat generated by the reaction of thiourea modified polyether amine and epoxy resin can stimulate the reaction of n only phenol and epoxy group, and then realize the continuity of the curing process, ensure the feasibility of the use of epoxy mortar in low temperature environment.

[0138] From the test results of comparative example 5 and comparative example 6, when the ratio of thiourea modified polyether amine and n only phenol is 1:1, the curing speed of epoxy mortar is too fast, which cannot provide sufficient operability time, and the mechanical properties after curing are greatly reduced; when the ratio of the two is 1:4, the curing speed of epoxy mortar in low temperature environment is too slow, and the mechanical properties after curing are also relatively low. Therefore, the best ratio of thiourea modified polyether amine and n only phenol is 1:(1.5-3.5).

[0139] From the test results of examples 8-17, it can be seen that the addition of modifier can obviously improve the operability time of epoxy mortar, and affect the mechanical properties of the curing system. When the modifier is the combination of polypropylene glycol diglycidyl ether and acetone, the epoxy mortar can have the best low temperature curing time, and the compressive strength after curing is higher. And when the proportion of acetone is less than 20%, it will not have any effect on the mechanical properties of the cured mortar system, and when the proportion of acetone is more than 20%, with the increasing proportion of acetone, the mechanical properties of the cured system become worse and worse, so the optimal ratio of polypropylene glycol diglycidyl ether and acetone is 1:(0.1-0.25).

[0140] The above is only the preferred embodiment of the present application, the protection scope of the present application is not limited to the above examples, any technical solution belonging to the idea of the present application is within the protection scope of the present application. It should be pointed out that for ordinary skilled in the art, some improvements and decorations without departing from the principle of the present application, these improvements and decorations should also be considered as the protection scope of the present application.

Claims

1. A high-strength epoxy mortar suitable for use in low-temperature environments, characterized in that, The A component includes the following components in the following weight parts: epoxy resin 100-150 parts, silane coupling agent 5-10 parts, titanium white 5-10 parts, anti-settling agent 5-10 parts, quartz sand 150-200 parts, talc 150-200 parts and 10-15 parts of modifier; the B component includes thiourea modified polyether amine and nonyl phenol, the weight ratio of the thiourea modified polyether amine to the nonyl phenol being 1:(1.5-3.5); the modifier is a mixture of polypropylene glycol diglycidyl ether and acetone in a weight ratio of 1:(0.1-0.25). The weight ratio of the thiourea modified polyether amine to the nonyl phenol is 1:2.

5. The silane coupling agent is selected from one of vinyltriethoxysilane, aminopropyltriethoxysilane, isobutyltriethoxysilane.

2. The high strength epoxy mortar suitable for construction in cryogenic environment as claimed in claim 1 wherein, The anti-settling agent is selected from one of fumed silica, organic bentonite, polyolefin wax.

3. The high strength epoxy mortar suitable for construction in cryogenic environment as claimed in claim 1 wherein, The method comprises the following steps:

4. The high strength epoxy mortar suitable for construction in cryogenic environment as claimed in claim 1, wherein, The epoxy resin, the silane coupling agent, the titanium white, the anti-settling agent, the quartz sand and the talc are mixed uniformly to obtain the A component, which is discharged and packaged; 5. A process for the preparation of high strength epoxy mortar suitable for use in cryogenic environments as claimed in any one of claims 1 to 4, characterised in that, The thiourea modified polyether amine and the nonyl phenol are mixed uniformly to obtain the B component, which is discharged and packaged. ​ ​

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