Epoxy resin-based mixture suitable for crab hole pouring and preparation method of epoxy resin-based mixture

Abstract

The invention belongs to the technical field of ecological restoration, and particularly relates to an epoxy resin-based mixture suitable for crab hole pouring and a preparation method thereof. The epoxy resin-based mixture can be efficiently cured within 12 minutes no matter in tap water or artificial seawater, has flowability and water sinking property, can be cured underwater, and is suitable for crab hole pouring.

Description

Technical Field

[0001] The invention belongs to the technical field of ecological restoration, and particularly relates to an epoxy resin-based mixture suitable for pouring crab holes and a preparation method thereof. Background Art

[0002] In the study of the ecological benefits of crab holes and related similar fields, the current commonly used method for rapid casting and repair of morphological structural models of crab holes and holes is to use cement-based materials or polymer composite materials for underwater casting. However, traditional composite materials are prone to phase separation or stratification during the mixing and casting process, resulting in the inability to form a stable miscible system inside the material, which in turn affects the structural density and mechanical properties after curing. For example, cement-based materials are prone to sedimentation and stratification due to density differences, while some polymer materials have poor compatibility with fillers, weak interface bonding, and insufficient long-term stability, making it difficult to meet the construction requirements of complex underwater environments.

[0003] Existing underwater curing materials usually rely on chemical additives or hydraulic components to adjust the curing speed, but there are significant limitations. For example, epoxy resin materials need to rely on specific curing agents and the curing time is difficult to shorten to less than 30 minutes; although fast-setting cement materials can shorten the curing time, they have poor early fluidity and are easily affected by water erosion. In addition, the accelerator introduced to speed up the curing may destroy the uniformity of the material and lead to an increase in internal defects. In the existing technology, there is still a blank solution that takes into account both underwater rapid curing and material stability, which seriously restricts the efficiency and quality of underwater repair projects.

[0004] Underwater casting materials must have both high fluidity to ensure dense filling and a moderate sinking speed to avoid material loss or uneven distribution due to excessive self-weight settling. In the prior art, high-fluidity materials often sink quickly due to high density or low viscosity, resulting in a void at the top of the cast body; while materials that are slowed down by thickeners may have insufficient fluidity due to increased viscosity, affecting the filling effect inside the crab hole. At present, there is no composite material that can achieve synergistic optimization of low viscosity, high fluidity and slow sinking characteristics in an underwater environment. This contradiction has become the core bottleneck restricting the casting effect.

[0005] From the above analysis, it can be seen that the development of a composite material with a stable miscible system, ultra-short underwater curing time, high fluidity and controllable sinking speed is of great significance to improving the efficiency and reliability of crab hole repair. Summary of the invention

[0006] The present invention develops an epoxy resin-based mixture, which includes E44 epoxy resin and polythiol curing agent, and can also be optimized by adding a sinking aid, so that the obtained crab hole casting composite material can achieve excellent casting effect.

[0007] To achieve the above object, the present invention may adopt the following technical solutions:

[0008] On the one hand, the present invention provides an epoxy resin-based mixture suitable for crab hole pouring, which comprises E44 epoxy resin and polythiol curing agent.

[0009] Preferably, in the above epoxy resin-based mixture, the mass ratio of E51 epoxy resin to polythiol curing agent is (1 - 4):1.

[0010] Preferably, in the above epoxy resin-based mixture, the mass ratio of E51 epoxy resin to polythiol curing agent is (1 - 2):1.

[0011] More preferably, in the above epoxy resin-based mixture, the mass ratio of E51 epoxy resin to polythiol curing agent is 1:1.

[0012] Preferably, the above epoxy resin-based mixture further comprises a sinking aid.

[0013] More preferably, in the above epoxy resin-based mixture, the sinking aid is selected from calcium carbonate and / or titanium dioxide.

[0014] More preferably, in the above epoxy resin-based mixture, the sinking aid is selected from calcium carbonate.

[0015] More preferably, in the above epoxy resin-based mixture, the mass ratio of E51 epoxy resin, polythiol curing agent and calcium carbonate is (1 - 4):1:(0.2 - 1).

[0016] More preferably, in the above epoxy resin-based mixture, the mass ratio of E51 epoxy resin, polythiol curing agent and calcium carbonate is 1:1:(0.2 - 0.4).

[0017] On the other hand, the present invention also provides a preparation method of the epoxy resin-based mixture in the present invention, which comprises: heating E51 epoxy resin in a water bath at 35°C - 40°C; then adding polythiol curing agent and / or sinking aid and mixing evenly to obtain the epoxy resin-based mixture.

[0018] The beneficial effects of the present invention include: The epoxy resin-based mixture provided by the present invention can be efficiently cured within 12 minutes both in tap water and artificial seawater, and has fluidity and sinking property, can achieve underwater curing, and is suitable for crab hole pouring. Description of the Drawings

[0019] Figure 1 Shows the underwater curing effects of epoxy resin, curing agent, additives (calcium carbonate, titanium dioxide, aluminum powder) under different ratios;

[0020] Figure 2 Shows the illustration of the underwater curing effect of epoxy resin with different proportions of calcium carbonate. Detailed implementation manners

[0021] The illustrated embodiments are for better explaining the present invention, but the content of the present invention is not limited only to the illustrated embodiments. Therefore, those skilled in the art make non-essential improvements and adjustments to the implementation manners according to the above-mentioned content of the invention, which still fall within the protection scope of the present invention.

[0022] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. Unless having significantly different meanings in the context, the expressions in singular form include those in plural form. As used herein, it should be understood that terms such as "including", "having", "containing" are intended to indicate the existence of features, numbers, operations, components, parts, elements, materials or combinations. The terms of the present invention are disclosed in the specification, and are not intended to exclude the possibility that one or more other features, numbers, operations, components, parts, elements, materials or their combinations may exist or can be added. As used herein, depending on the circumstances, " / " can be interpreted as "and" or "or".

[0023] To better understand the present invention, the content of the present invention will be further clarified below in conjunction with specific examples, but the content of the present invention is not limited only to the following examples.

[0024] In the following examples, the test sediments were collected from the Neilingding Futian Nature Reserve in Guangdong; the E51 epoxy resin was the epoxy powder from Nantong Xingchen Synthetic Materials Co., Ltd.; the model of the polythiol curing agent was TSG-9018, and the polythiol curing agent was from Guangzhou Wanhua New Materials Technology Co., Ltd.; the E44 epoxy resin was 6101 epoxy resin, and the E44 epoxy resin was from Guangzhou Fufei Chemical Technology Co., Ltd.; the T31 curing agent was a phenolic amine epoxy curing agent, analytical pure, and the T31 curing agent was from Tianjin Sanhe Chemical Technology Co., Ltd.; the calcium carbonate was from Jiangxi Mingyuan High-Tech Materials Co., Ltd.; the model of the titanium dioxide was R-2233, analytical pure, and the titanium dioxide was from Shanghai Yitai Chemical Co., Ltd.; the model of the aluminum powder was HC30-400, analytical pure, and the aluminum powder was from Shenzhen Hangcai Chemical Co., Ltd.

[0025] I. Optimal curing ratio of epoxy resin and curing agent

[0026] (1) Prepare 4 basins (diameter 35 cm, depth 25 cm), fill them with sediments, level them after treatment, and dig 4 holes (diameter 1.5 cm, depth 5 cm) in the basins to simulate crab holes. Mark basins 1 and 2 and add artificial seawater (proportion: 35‰, that is, add 35 g of salt to 965 g of water), and use tap water for basins 3 and 4 as the control group;

[0027] (2) Adjust the water bath heating box and heat the water to 35 °C;

[0028] (3) Weigh a certain amount of epoxy resin in 4 beakers respectively, mark and record the grams.

[0029] (4) Put the weighed epoxy resin into a water bath heating box for heating.

[0030] (5) Weigh the curing agent (the ratio of epoxy resin to curing agent is: Beaker No. 1: 1:1, Beaker No. 2: 2:1, Beaker No. 3: 3:1, Beaker No. 4: 4:1), and add the curing agent.

[0031] (6) Gently stir with a stirrer to make it evenly mixed, avoiding large air bubbles that may affect the experiment.

[0032] (7) After stirring, pour it into the simulated crab hole, and record the start time and temperature.

[0033] (8) Use a needle to pick it every 8 minutes, and record the curing state and time.

[0034] Different epoxy resins and curing agents are processed according to the above method, and different situations are shown in Table 1 below.

[0035] Table 1 Epoxy resin ratio and curing characteristics

[0036]

[0037]

[0038] Note: Moderate viscosity < relatively viscous < viscous < very viscous

[0039] It can be seen from Table 1 above that:

[0040] First, under the condition of the same water temperature, tap water and artificial seawater have no influence on the curing time of the epoxy resin-based mixture.

[0041] Second, as the ratio of E44 epoxy resin + T31 curing agent gradually increases, the complete curing time gradually increases from 1 hour to 4 hours. When pouring into the overflowing water cave, it floats on the water surface and can be cured.

[0042] Third, as the ratio of E44 epoxy resin + polythiol curing agent TSG-9018 gradually increases, the complete curing time gradually increases from 5 minutes to 8 minutes. When pouring into the overflowing water cave, it has a certain sinking property and can be cured.

[0043] Fourth, as the ratio of E51 epoxy resin + polythiol curing agent TSG-9018 gradually increases, the complete curing time gradually increases from 12 minutes to 16 minutes. When pouring into the overflowing water cave, it has fluidity and sinking property and can be cured underwater.

[0044] Fifthly, E51 epoxy resin + T31 curing agent floats on the water surface at any ratio, can be cured, and the complete curing time is 4 hours for all cases.

[0045] From the above, it can be known that the combination of E51 epoxy resin and polythiol curing agent TSG-9018 is the best, and the optimal ratio is 1:1.

[0046] II. Improvement of the underwater curing effect of epoxy resin based on additives

[0047] (1) Prepare several disposable beakers, stirring rods, electronic scales, additives (calcium carbonate, titanium dioxide or aluminum powder), and E51 epoxy resin.

[0048] (2) Weigh 50 g of E51 epoxy resin and heat it in a water bath to 35 °C.

[0049] (3) Weigh 50 g of polythiol curing agent TSG-9018 and weigh the additives for standby at the same time.

[0050] (4) Add the polythiol curing agent TSG-9018 and the additives to the E51 epoxy resin, and quickly stir with a stirring rod to fully mix to obtain a mixed solution.

[0051] (5) Pour the stirred mixed solution into artificial seawater (ratio: 35‰), and observe and record the floating and sinking status after 12 minutes (at an air temperature of 19 °C).

[0052] Select different types and different weights of additives and process them according to the above method. The floating and sinking status is as shown in Table 2 below and Figure 1 The

[0053] Table 2 Floating and sinking status of different types and different weights of additives

[0054]

[0055] From the above Table 2 and Figure 1 it can be seen that:

[0056] Firstly, as the proportion of the additive calcium carbonate gradually increases, the epoxy resin has stable sinking property in 35‰ artificial seawater ( Figure 1 a, 1d, and 1g), indicating that calcium carbonate and epoxy resin form a stable mutual solubility system;

[0057] Secondly, as the proportion of titanium dioxide gradually increases, the epoxy resin cannot all sink ( Figure 1 b, 1e, and 1h), and obvious stratification occurs, indicating that the compatibility between titanium dioxide and epoxy resin is poor;

[0058] Thirdly, as the proportion of aluminum powder gradually increases, the epoxy resin has never been able to sink ( Figure 1c, 1f, and 1i), indicating that aluminum powder fails to improve the water-sinking property of epoxy resin.

[0059] From the above, it can be known that calcium carbonate is most suitable as an additive for epoxy resin to increase its water-sinking property.

[0060] III. Field Crab Hole Simulation Pouring Test

[0061] Based on the above experiments, a simulated crab hole pouring test was carried out.

[0062] (1) Prepare several disposable beakers, stirring rods, electronic scales, additives (calcium carbonate, titanium dioxide, aluminum powder), and E51 epoxy resin;

[0063] (2) Weigh 50 g of E51 epoxy resin and heat it in a water bath to 35 °C;

[0064] (3) Weigh 50 g of polythiol curing agent TSG-9018 and weigh calcium carbonate (5 g, 10 g, 15 g, 20 g, 25 g, 30 g, 35 g, 40 g, 45 g, and 50 g) for standby;

[0065] (4) Add the polythiol curing agent TSG-9018 and calcium carbonate to the E51 epoxy resin, and quickly stir with a stirring rod to fully mix to obtain a mixed solution.

[0066] (5) Pour the mixed solution into the simulated crab hole, observe and record the floating and sinking conditions.

[0067] The floating and sinking conditions of calcium carbonate with different weights are shown in Table 3 below.

[0068] Table 3 Characteristics of the underwater curing process of epoxy resin with different proportions of calcium carbonate added

[0069]

[0070] As can be seen from Table 3 above, when the calcium carbonate addition amount is 5 g, there is no specific reaction and it floats on the water surface; when it is from 10 g to 20 g, it slowly sinks; when it is from 25 g to 35 g, it sinks quickly but the fluidity starts to deteriorate and it is not easy to stir; when it is from 40 g to 50 g, the fluidity is affected, the sinking speed is the fastest, and the stirring resistance is huge.

[0071] In addition, the curing effects of calcium carbonate with different weights are as Figure 2 shown (in the figure, from left to right are the calcium carbonate addition amounts of 5 g to 50 g in Table 3 above), and the results show that when 10 g to 20 g of calcium carbonate is added (red frame), the sinking depth is the deepest and the epoxy resin spreading out of the hole is the smallest.

[0072] As can be seen above, when there are 50g of epoxy resin and 50g of curing agent, adding 10g - 20g of calcium carbonate can significantly improve its sedimentation effect while ensuring curing, and it is expected to achieve the effect of successfully pouring the crab hole.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. An epoxy resin-based mixture suitable for crab hole casting, characterized in that: Includes E44 epoxy resin and polythiol curing agent.

2. The epoxy resin-based mixture according to claim 1, characterized in that The mass ratio of E51 epoxy resin and polythiol curing agent is (1-4):

1.

3. The epoxy resin-based mixture according to claim 2, characterized in that The mass ratio of E51 epoxy resin and polythiol curing agent is (1-2):

1.

4. The epoxy resin-based mixture according to claim 3, characterized in that The mass ratio of E51 epoxy resin and polythiol curing agent is 1:

1.

5. The epoxy resin-based mixture according to any one of claims 1 to 3, characterized in that The epoxy resin based mixture also includes a sinking aid.

6. The epoxy resin-based mixture according to claim 4, characterized in that The sinking aid is selected from calcium carbonate and / or titanium dioxide.

7. The epoxy resin-based mixture according to claim 5, characterized in that The sinking aid is selected from calcium carbonate.

8. The epoxy resin-based mixture according to claim 6, characterized in that The mass ratio of E51 epoxy resin, polythiol curing agent and calcium carbonate is (1-4):1:(0.2-1).

9. The epoxy resin-based mixture according to claim 6, characterized in that The mass ratio of E51 epoxy resin, polythiol curing agent and calcium carbonate is 1:1:(0.2-0.4).

10. A method for preparing an epoxy resin-based mixture according to any one of claims 5 to 9, comprising: Heat the E51 epoxy resin in a water bath at 35°C-40°C; then add the polythiol curing agent and the sinking aid and mix well to obtain an epoxy resin-based mixture.

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