Transparent weather-resistant glass fiber composite material, preparation method thereof and application of transparent weather-resistant glass fiber composite material in oil and gas pipeline repair

Abstract

The invention belongs to the field of composite materials, and particularly relates to a transparent weather-proof glass fiber composite material, a preparation method thereof and application of the transparent weather-proof glass fiber composite material in oil and gas pipeline repair. A main body of the composite material is formed by dipping glass fiber cloth in epoxy resin adhesive liquid, and then a transparent weather-proof chemical coating is sprayed or coated on the surface of the main body of the composite material. The repairing method of the oil and gas pipeline comprises the following steps that (1) after the surface of a pipeline reinforcing area is polished and cleaned, the defect position of the pipeline is repaired through filling and leveling putty, and then the surface is coated with anti-corrosion primer; (2) winding glass fiber cloth outside the primer, dipping epoxy resin adhesive liquid on the glass fiber cloth, and heating and curing; and (3) spraying the transparent weather-proof chemical coating onto the surface of the glass fiber cloth, and heating and curing to form a film, thereby finishing the repair of the oil and gas pipeline. The transparent weather-resistant glass fiber composite material disclosed by the invention has excellent weather resistance and visibility of an internal structure of the material.

Description

Technical Field

[0001] The present invention belongs to the field of composite materials, and particularly relates to a transparent weather-resistant glass fiber composite material, a preparation method thereof, and an application thereof in the repair of oil and gas pipelines. Background Art

[0002] During the operation of oil and gas pipelines, on the one hand, they have to withstand high pressure, and on the other hand, they are also subject to long-term corrosion by the internal conveying medium, resulting in great potential safety hazards in the in-service pipelines, and thus causing huge property losses and casualties. Therefore, for the defects of in-service oil and gas pipelines, especially the repair and reinforcement at the position of the pipeline girth weld, is an extremely important task.

[0003] In the prior art, the method of externally bonding carbon fiber reinforced composite materials is one of the main methods for pipeline reinforcement. Carbon fiber reinforced composite materials have the characteristics of high strength (the tensile strength is equivalent to 10 times that of ordinary steel), high specific strength and specific stiffness, small elongation, and light weight. However, the weather resistance of carbon fiber reinforced composite materials is usually poor, and it is easily affected by the environment (ultraviolet irradiation, rain erosion) and the conveying medium during the application of pipeline reinforcement, which easily leads to the failure of the bonding between the polymer matrix and the fiber inside the material, causing a significant decrease in the performance of the composite material and seriously affecting the service life of the material. In addition, carbon fiber composite materials are usually opaque, and during their long-term outdoor application, we cannot directly observe whether the carbon fiber and the polymer matrix inside the composite material are still well bonded. Therefore, there is a sudden failure when externally bonding carbon fiber reinforced composite materials to reinforce pipelines, which will cause pipeline accidents and thus result in huge property losses and hazards. Summary of the Invention

[0004] Aiming at the problems and deficiencies existing in the prior art, the present invention provides a transparent weather-resistant glass fiber composite material, and also provides a preparation method of the composite material, and an application of the composite material in the repair of oil and gas pipelines.

[0005] Based on the above purposes, the present invention adopts the following technical solutions:

[0006] In the first aspect, the present invention provides a transparent weather-resistant glass fiber composite material (GFRP), which is composed of a glass fiber cloth, an epoxy resin adhesive solution, and a transparent weather-resistant chemical coating.

[0007] The preparation method of the epoxy resin adhesive solution is: mixing a refractive index adjusting liquid, a liquid epoxy resin, a curing agent, and an initiator evenly to obtain the epoxy resin adhesive solution.

[0008] In the epoxy resin adhesive solution, by weight, there are 50 - 70 parts of liquid epoxy resin, 15 - 20 parts of curing agent, and 0.02 - 0.06 parts of initiator; the amount of the refractive index adjusting liquid is to adjust the refractive index to 1.5632 - 1.5665.

[0009] Preferably, in the epoxy resin adhesive solution, by weight, there are 60 parts of liquid epoxy resin, 18 parts of curing agent, and 0.04 parts of initiator; the amount of the refractive index adjusting liquid is to adjust the refractive index to 1.5644.

[0010] The refractive index adjusting liquid is any one of acrylate monomers and silane coupling agents, preferably a silane coupling agent, and more preferably KH - 570 coupling agent.

[0011] As a preferred solution, the refractive index adjusting liquid is an acrylate monomer, and the mass parts of the acrylate monomer are 5 - 15 parts.

[0012] As a more preferred solution, the refractive index adjusting liquid is a silane coupling agent, and the mass parts of the silane coupling agent are 0 - 8 parts.

[0013] The epoxy resin is bisphenol A type epoxy resin, preferably any one of E - 42 epoxy resin, E - 51 epoxy resin, E - 44 epoxy resin, and E - 55 epoxy resin, and more preferably E - 51 epoxy resin.

[0014] The curing agent is any one of anhydride curing agents, polyamide curing agents, polyetheramine curing agents, and imidazole curing agents, preferably a polyetheramine curing agent, and more preferably polyetheramine D230 curing agent.

[0015] The initiator is benzoyl peroxide.

[0016] The preparation method of the transparent weather - resistant chemical coating is as follows: Mix ethanol and tetraethyl orthosilicate, then add polydimethylsiloxane and mix evenly to obtain a mixed solution. Add water to the mixed solution and mix evenly to obtain a sol. Adjust the pH value of the sol to 7.0 ± 0.5. Then, add trichloromethylsilane to the sol and mix evenly to obtain the transparent weather - resistant chemical coating.

[0017] In the transparent weather - resistant chemical coating, by weight, there are 20 - 30 parts of ethanol, 1.5 - 2.0 parts of tetraethyl orthosilicate, 1.5 - 3 parts of polydimethylsiloxane, 3 - 10 parts of water, and 0 - 0.45 parts of trichloromethylsilane.

[0018] Preferably, in the transparent weather - resistant chemical coating, by weight, there are 25 parts of ethanol, 1.8 parts of tetraethyl orthosilicate, 2 parts of polydimethylsiloxane, 5 parts of water, and 0.2 parts of trichloromethylsilane.

[0019] The water is distilled water.

[0020] The pH value of the sol is adjusted by any one of hydrochloric acid and carbonic acid, and hydrochloric acid is preferably used.

[0021] The thickness of the glass fiber cloth is 0.1 - 0.12 mm, and the tensile strength is 2130 - 2200 MPa.

[0022] The glass fiber cloth is any one of E - glass fiber, C - glass fiber, S - glass fiber, and AR - glass fiber, and E - glass fiber is preferably used.

[0023] In a second aspect, the present invention provides an application of the transparent weather - resistant glass fiber composite material described in the first aspect in the repair of oil and gas pipelines.

[0024] In a third aspect, the present invention provides a repair method of the transparent weather - resistant glass fiber composite material described in the second aspect in the repair of oil and gas pipelines. The repair method of the oil and gas pipeline includes the following steps:

[0025] (1) After grinding and cleaning the surface of the pipeline reinforcement area, use a filling putty to repair the pipeline defects, and then apply an anti - corrosion primer on the surface;

[0026] (2) Wind the glass fiber cloth outside the primer, and then impregnate the epoxy resin adhesive solution on the glass fiber cloth and heat - cure it;

[0027] (3) Spray the transparent weather - resistant chemical coating onto the surface of the glass fiber cloth and heat - cure it to form a film, thus completing the repair of the oil and gas pipeline.

[0028] The grinding standard in step (1) is Sa2.5 level or St3.0 level required in GB / T 8923.1.

[0029] The cleaning in step (1) uses anhydrous ethanol.

[0030] The filling putty in step (1) is composed of epoxy resin and a curing agent.

[0031] In the filling putty, by weight, there are 65 - 75 parts of epoxy resin and 25 - 35 parts of curing agent.

[0032] The epoxy resin is bisphenol A type epoxy resin, and any one of E - 42 epoxy resin, E - 51 epoxy resin, E - 44 epoxy resin, and E - 55 epoxy resin is preferably used, and E - 44 epoxy resin is more preferably used.

[0033] The curing agent is 593 curing agent.

[0034] In step (1), the anti - corrosion primer is an epoxy - based zinc - rich primer.

[0035] Furthermore, the epoxy zinc-rich primer is composed of epoxy resin, polyamide, ultrafine zinc powder, aluminum silver paste, and iron oxide red.

[0036] The winding thickness calculation formula in step (2) is:

[0037]

[0038] Where: h GFRP represents the winding thickness of the fiberglass cloth, h represents the pipe wall thickness, h R represents the wall thickness at the defect, σ R represents the tensile strength of the pipe material, σ GFRP represents the tensile strength of the fiberglass cloth.

[0039] In step (2), the heating and curing temperature is 60 - 80 °C.

[0040] In step (3), the heating and curing temperature is 30 - 50 °C.

[0041] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0042] 1. In the epoxy resin adhesive of the present invention, by using KH-570 silane coupling agent to modify the epoxy resin and introducing Si-O bonds into the three-dimensional structure of the epoxy resin, not only can the refractive index of the epoxy resin be adjusted, but also when the epoxy resin adhesive impregnates the fiberglass, the KH-570 silane coupling agent is connected to the fiberglass through the formed Si-O-Si chemical bond. The double bond forms a polymer structure containing siloxane side chains under the action of the initiator benzoyl peroxide. The polymer chain and the polymer chain of the epoxy resin are entangled or interconnected through a network structure, increasing the compatibility of the fiberglass. And after spraying the transparent weather-resistant chemical coating, the remaining polymer containing alkoxy side chains can form a certain chemical cross-linking structure with the chemical coating, enhancing the interlaminar shear force between the chemical coating and the fiberglass.

[0043] 2. On the one hand, the transparent weather-resistant fiberglass composite material of the present invention has excellent weather resistance, reducing the influence of the environment and the conveying medium on its performance and extending the service life of the material. On the other hand, its optical transparency gives visibility to the internal structure of the material, enabling timely detection of potential safety hazards inside the material and preventing adverse effects on the pipeline caused by sudden failure of the material. Description of the Drawings

[0044] Figure 1 It is a comparison chart of the light transmittance results of Comparative Sample 1, Samples 1-2, 2-1, 2-2, and 2-3;

[0045] Figure 2 It is a comparison chart of the haze results of Comparative Sample 1, Samples 1-2, 2-1, 2-2, and 2-3;

[0046] Figure 3 It is a photo showing the transparency of Sample 2-1 in the outdoor natural environment;

[0047] Figure 4 It is a photo showing the water contact angle of the composite material prepared for Sample 2-1. Detailed implementation manners

[0048] To make the objectives, technical solutions and advantages of the present invention clearer and more definite, the present invention will be further described in detail below through embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0049] Embodiment 1

[0050] A transparent weather-resistant glass fiber composite material is prepared through the following steps:

[0051] (1) Prepare an epoxy resin adhesive solution: Take E-51 epoxy resin, polyetheramine D230 curing agent, KH570 coupling agent and benzoyl peroxide according to Table 1, mix them evenly and then let stand for 20 min to obtain the epoxy resin adhesive solution.

[0052] (2) Prepare a transparent weather-resistant chemical coating material: Take 25 parts of ethanol and 1.8 parts of tetraethyl orthosilicate by weight, mix them, then add 2 parts of polydimethylsiloxane and continue to mix for 1 h to obtain a mixed solution. Add 5 parts of distilled water to the mixed solution and mix until a clear sol state is formed to obtain a sol. Adjust the pH value of the sol to 7.0 using hydrochloric acid. Then, add 0.2 part of trichloromethylsilane to the sol and continue to mix for 1 h to obtain the transparent weather-resistant chemical coating.

[0053] (3) Pretreat the surface of the pipeline reinforcement area: Use 60# and 150# sandpapers to polish and remove rust from the surface of the damaged area of the oil and gas pipeline to be repaired. After polishing to Sa2.5 level, clean it with anhydrous ethanol, and then use a filling putty to repair the pipeline defects until it is flat and void-free. In the filling putty, by weight, there are 75 parts of epoxy resin and 25 parts of curing agent. After the repair is completed, apply a layer of epoxy zinc-rich primer on the surface.

[0054] (4) Prepare a transparent weather-resistant glass fiber composite material on the surface of the damaged oil and gas pipeline to form a repair layer: Apply a certain pre-tightening force to an E-glass fiber cloth with a thickness of 0.12 mm and a tensile strength of 2200 MPa, and wind it around the area of the oil and gas pipeline to be repaired and reinforced with a winding thickness of 1.5 mm. Then, impregnate the epoxy resin adhesive solution prepared in step (1) on the glass fiber cloth and cure it by heating at 80°C;

[0055] Use a spray gun with a needle size of 0.4 mm, a pressure of 0.5 MPa, and a flow rate of 10 mL / min to evenly spray the transparent weather-resistant chemical coating material prepared in step (2) onto the E-glass fiber cloth impregnated in step (4), and then heat and cure it into a film at 50 °C to complete the repair of the oil and gas pipeline.

[0056] Prepare 5 oil and gas pipelines, numbered as oil and gas pipelines 1 to 5, and artificially damage them to the same degree as experimental materials. Samples 1-1 to 1-5 in Table 1 correspond to the repaired oil and gas pipelines 1 to 5 respectively.

[0057] Conduct performance tests on the repair layers of oil and gas pipelines 1 to 5. The test standards are as follows:

[0058] Transmittance: According to the current national standard GB / T 2410-2008, use an ultraviolet spectrophotometer to measure the transmittance of the composite material at wavelengths from 400 nm to 800 nm, and take the maximum transmittance at each wavelength as the transmittance of the composite material.

[0059] Tensile strength: Evaluate the tensile properties on a universal testing machine (AGX-100PLUS, Shimadzu, Japan) to characterize the mechanical properties of the composite material. The tensile specimens are designed according to ASTM-D039 standard, and the samples are cut using a water jet cutter with dimensions of 250 mm (length) × 15 mm (width) × 1 mm (thickness). During the test, a gauge length of 120 mm and a crosshead displacement rate of 1 mm / min are used. Five measurements are made for each composite material during the mechanical property test, and the average value is reported.

[0060] Flexural strength: Measure the flexural strength of the composite material using a universal testing machine (AGX-100PLUS, Shimadzu, Japan) according to the current national standard GB / T 1449-2005.

[0061] Shear strength: Measure the shear strength of the composite material using a universal testing machine (AGX-100PLUS, Shimadzu, Japan) according to the current national standard GB / T 28889-2012.

[0062] Haze: Measure the haze of the composite material using a WGT-S haze tester according to the current national standard GB / T 2410-2008.

[0063] Water contact angle: Measure the water contact angle of the glass composite material at room temperature using a water contact angle measuring instrument according to the current national standard GB / T 24368-2009.

[0064] Water absorption rate: According to the current national standard GB / T 2573-2008, using distilled water as the medium, the water absorption rate of the composite material was measured by boiling it in a constant temperature water bath at 60°C for 24 hours.

[0065] The light transmittance retention rate and tensile strength retention rate are calculated according to the current national standard GB / T 2573-2008 by the following formula:

[0066]

[0067] Where R i represents the light transmittance (tensile strength retention rate) (%) after the i-th test cycle; represents the arithmetic mean of the light transmittance (tensile strength) of each group of specimens after the i-th test cycle; represents the arithmetic mean of the initial light transmittance (tensile strength) of the specimens;

[0068] The test results are shown in Table 1. It can be seen that with the increase of the content of E-51 epoxy resin, the light transmittance, tensile strength, flexural strength and shear strength all show a trend of first increasing and then decreasing, while the haze value shows the opposite trend, first decreasing and then increasing. In the comparative experiment of changing the curing agent content, with the increase of the curing agent content, the trends shown by the light transmittance, tensile strength, flexural strength and shear strength are similar to those of changing the epoxy content, while the haze value first increases and then begins to decrease with the increase of the content.

[0069] Table 1 Test results of epoxy resin adhesive with different ratios and properties

[0070]

[0071]

[0072] Example 2

[0073] A transparent weather-resistant glass fiber composite material is prepared by the following steps:

[0074] (1) Prepare epoxy resin adhesive: Mix 60 parts of E-51 epoxy resin, 18 parts of polyetheramine D230 curing agent, KH570 coupling agent and 0.04 parts of benzoyl peroxide evenly and let it stand for 20 minutes to obtain epoxy resin adhesive. Multiple different addition amounts of KH570 coupling agent are set to facilitate comparing the influence of the addition amount of coupling agent on the product performance, which are 0 part, 4 parts, 6 parts, 8 parts respectively. As shown in Table 2, the corresponding composite material numbers are Comparative 1, Sample 2-1, Sample 2-3, Sample 2-4.

[0075] (2) Prepare transparent weather-resistant chemical coating material: The same as in Example 1.

[0076] (3) Pretreat the surface of the pipeline reinforcement area: same as in Example 1.

[0077] (4) Prepare a transparent weather-resistant glass fiber composite material on the surface of the damaged oil and gas pipeline to form a repair layer: same as in Example 1.

[0078] Example 3

[0079] Refer to Example 2 to prepare the glass fiber composite material, the difference is that a weather-resistant transparent chemical coating is not sprayed on the surface of the E-glass fiber cloth after impregnation in step (4). The obtained composite material is marked as Comparative Sample 2.

[0080] Example 4

[0081] Refer to Example 2 to prepare the glass fiber composite material, the difference is that a weather-resistant transparent chemical coating is not sprayed on the surface of the E-glass fiber cloth after impregnation in step (4). The obtained composite material is marked as Comparative Sample 3.

[0082] Example 5

[0083] Refer to the test method of Example 1 to conduct performance tests on the repair layers of the repaired oil and gas pipelines in Examples 2 to 5. The test results are shown in Table 1. Among them, the light transmittance test results of the composite materials prepared from Comparative Sample 1, Sample 1-2, Sample 2-1, Sample 2-2, and Sample 2-3 are as Figure 1 shown, and the haze results are as Figure 2 shown.

[0084] Table 2 Performance determination results of samples with different addition amounts of KH570 and comparative samples

[0085]

[0086]

[0087] As shown in Table 1, Figure 1 , 2 shown, the addition of the KH-570 coupling agent improves the light transmittance, light transmittance retention rate, tensile strength, tensile strength retention rate, and water contact angle of the composite material, reduces its haze and water absorption rate, and makes the composite material exhibit very excellent optical properties, mechanical properties, and relatively good weather resistance. Among them, Sample 2-1 has the best comprehensive performance. Refer to the preparation process of Sample 2-1 to prepare the composite material on flat glass. Its transparency under outdoor natural environment is as Figure 3 shown, and the water contact angle is as Figure 4 shown.

[0088] Comparing the repaired oil and gas pipelines of Sample 1-2, Sample 2-1, Sample 2-2, Sample 2-3 with the repaired oil and gas pipeline of Comparative Sample 2, it can be seen that the transparent weather-resistant chemical coating not only improves the optical properties of the composite material to a certain extent, but also greatly enhances its weather resistance.

[0089] Comparing the repaired oil and gas pipelines of Sample 1-2, Sample 2-1, Sample 2-2, Sample 2-3 with the repaired oil and gas pipeline of Comparative Sample 3, it can be seen that the mechanical strength of the transparent glass fiber-reinforced composite material developed by the present invention is similar to that of the carbon fiber-reinforced composite material, but it has unique optical transparency.

[0090] Therefore, through a repair method of a transparent weather-resistant glass fiber composite material provided by the present invention in the repair of oil and gas pipelines, on the one hand, it has excellent weather resistance, reduces the influence of the environment on its performance, and greatly extends the service life. On the other hand, the high optical transparency of the material enables the observation of internal defects of the material, preventing the adverse effects caused by the sudden failure of the reinforcement material on the normal operation of the pipeline.

[0091] The above describes the preferred embodiments of the present invention, but it should be understood that the invention is not limited to the content disclosed herein. As long as non-substantial improvements are made by adopting the method concept and technical solution of the present invention, or the method concept and technical solution of the present invention are applied to other occasions, they are all within the protection scope of the present invention.

Claims

1. A transparent weather-resistant glass fiber composite material, characterized in that, The main body of the composite material is formed by impregnating a glass fiber cloth with an epoxy resin adhesive solution, and then a transparent weather-resistant chemical coating is sprayed or coated on the surface of the composite material body.

2. The transparent weather-resistant glass fiber composite material according to claim 1, wherein The preparation method of the epoxy resin adhesive solution is: mixing a refractive index adjusting liquid, a liquid epoxy resin, a curing agent, and an initiator evenly to obtain the epoxy resin adhesive solution.

3. The transparent weather-resistant glass fiber composite material according to claim 2, characterized in that, In the epoxy resin adhesive solution, by weight, 50-70 parts of the liquid epoxy resin, 15-20 parts of the curing agent, and 0.02-0.06 parts of the initiator; the amount of the refractive index adjusting liquid is to adjust the refractive index to 1.5632-1.5665.

4. The transparent weather-resistant glass fiber composite material according to claim 3, characterized in that The refractive index adjusting liquid is any one of an acrylate monomer and a silane coupling agent; when the refractive index adjusting liquid is an acrylate monomer, the mass part of the acrylate monomer is 5-15 parts; when the refractive index adjusting liquid is a silane coupling agent, the mass part of the silane coupling agent is 0-8 parts.

5. The transparent weather-resistant glass fiber composite material according to claim 1, characterized in that The preparation method of the transparent weather-resistant chemical coating is: mixing ethanol and tetraethyl orthosilicate, then adding polydimethylsiloxane and mixing evenly to obtain a mixed solution, adding water to the mixed solution and mixing evenly to obtain a sol, adjusting the pH value of the sol to 7.0±0.5, and then adding trichloromethylsilane to the sol and mixing evenly to obtain the transparent weather-resistant chemical coating.

6. The transparent weather-resistant glass fiber composite material according to claim 5, wherein In the transparent weather-resistant chemical coating, by weight, 20-30 parts of ethanol, 1.5-2.0 parts of tetraethyl orthosilicate, 1.5-3 parts of polydimethylsiloxane, 3-10 parts of water, and 0-0.45 parts of trichloromethylsilane.

7. The application of the transparent weather-resistant glass fiber composite material as described in claims 1-6 in the repair of oil and gas pipelines.

8. The repair method of the transparent weather-resistant glass fiber composite material as described in claims 1-6 for repairing oil and gas pipelines, characterized in that, The repair method of the oil and gas pipeline includes the following steps: (1) After grinding and cleaning the surface of the pipeline reinforcement area, use a leveling putty to repair the pipeline defects, and then apply an anti-corrosion primer on the surface; (2) Wind a glass fiber cloth outside the primer, and then impregnate the epoxy resin adhesive solution on the glass fiber cloth and heat it for curing; (3) Spray the transparent weather-resistant chemical coating onto the surface of the glass fiber cloth and heat it for curing to form a film, that is, complete the repair of the oil and gas pipeline.

9. The repair method of the transparent weather-resistant glass fiber composite material for repairing oil and gas pipelines as described in claim 8, characterized in that, The leveling putty described in step (1) is composed of an epoxy resin and a curing agent.

10. The repair method of the transparent weather-resistant glass fiber composite material as claimed in claim 8 for repairing oil and gas pipelines, characterized in that, The anti-corrosion primer described in step (1) is an epoxy-based zinc-rich primer.

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