Dual-curing front-line polymer resin system for repairing fan blade and preparation method of dual-curing front-line polymer resin system

Abstract

The invention discloses a dual-curing front-line polymer resin system for repairing a fan blade and a preparation method. The dual-curing front-line polymer resin system is prepared from mixed resin and an initiator, the mixed resin comprises the following components in parts by weight: 80-90 parts of epoxy resin, 8-12 parts of polyfunctional acrylate and 2-8 parts of monofunctional acrylate; the initiator comprises a photoinitiator, a photosensitizer and a thermal initiator, and the mass ratio of the photoinitiator to the photosensitizer to the thermal initiator is (4-6): 1: (2-3); according to the dual-curing frontline polymerization resin system disclosed by the invention, through selection of all the raw materials, a form of photo-initiated frontline polymerization can be adopted, reaction heat pushes the movement towards the thickness direction before polymerization while the surface is rapidly cured by ultraviolet light, so that additional heat source equipment is not needed while complete curing of a thick-layer material and a colored system is realized, and the dual-curing frontline polymerization resin system is simple and convenient to operate and green and environment-friendly.

Description

Technical Field

[0001] The present invention relates to the technical field of fan blade repair, and particularly relates to a dual-curing front polymerization resin system for fan blade repair and a preparation method thereof. Background Art

[0002] Wind power technology is the technology of using wind energy to generate electricity, mainly relying on manufacturing wind turbines. Since wind energy is a renewable and environmentally friendly energy source, the development of wind power technology is the main development strategy of many countries today. Therefore, wind power technology, as a kind of clean energy, has received extensive attention.

[0003] As a core component of a wind turbine generator set, a wind turbine blade is usually made of a composite of resin and fiberglass cloth, and plays an important role in capturing wind energy during the power generation process. With technological innovation and market iteration, while wind turbine blades are gradually developing towards being offshore and large-scale, their manufacturing difficulty and the number of defects have also increased synchronously. Currently, when repairing defects of wind turbine blades, a thermosetting epoxy resin system is mostly used, which requires a long heating and curing stage, ultimately resulting in an increase in manufacturing cost and an extension of the molding cycle.

[0004] Therefore, there is an urgent need to develop and improve a curing technology for the repair and reinforcement of wind turbine blades to shorten the molding cycle and reduce the production cost. Summary of the Invention

[0005] The purpose of the present invention is to provide a dual-curing front polymerization resin system for fan blade repair and a preparation method thereof. Through the selection of various raw materials, the dual-curing front polymerization resin system of the present invention can, in the form of photoinitiated front polymerization, while rapidly curing the surface under ultraviolet light, use the reaction heat to push the polymerization front to move in the thickness direction, achieving complete curing of thick-layer materials and colored systems without the need for additional heat source equipment, with simple operation and being environmentally friendly.

[0006] In order to achieve the above object of the present invention, the following technical solutions are specifically adopted:

[0007] The first aspect of the present invention provides a dual-curing front polymerization resin system for fan blade repair, and the dual-curing front polymerization resin system is composed of a mixed resin and an initiator;

[0008] The mixed resin includes the following components in parts by weight:

[0009] 80 - 90 parts of epoxy resin, 8 - 12 parts of polyfunctional acrylate, and 2 - 8 parts of monofunctional acrylate; the polyfunctional acrylate is composed of difunctional acrylate, trifunctional acrylate, and tetrafunctional acrylate;

[0010] The initiator comprises a photoinitiator, a photosensitizer and a thermal initiator, and the mass ratio of the photoinitiator, the photosensitizer and the thermal initiator is (4-6):1:(2-3).

[0011] Preferably, the mass ratio of the initiator to the mixed resin is (1-2):100.

[0012] Preferably, the epoxy resin is 3,4'-epoxycyclohexylmethyl 3,4'-epoxycyclohexanecarboxylate.

[0013] Preferably, the mass ratio of the difunctional acrylate, the trifunctional acrylate and the tetrafunctional acrylate is (2-4):(6-10):(4-6); the difunctional acrylate is 1,6-hexanediol diacrylate; the trifunctional acrylate is trimethylolpropane triacrylate; the tetrafunctional acrylate is di(trimethylolpropane) tetraacrylate.

[0014] Preferably, the monofunctional acrylate is isobutyl acrylate and / or isobornyl acrylate.

[0015] Preferably, the photoinitiator is a cationic photoinitiator, and the cationic photoinitiator is diaryliodonium salt or triarylsulfonium salt.

[0016] Preferably, the photosensitizer is 2-isopropylthioxanthone.

[0017] Preferably, the thermal initiator is at least one of azobisisobutyronitrile, benzoyl peroxide and 1,1-di-tert-butylperoxycyclohexane.

[0018] The second aspect of the present invention provides a method for preparing the above double-curing front polymerization resin system, which is characterized in that the preparation method comprises the following steps:

[0019] (a) According to parts by weight, mix the epoxy resin, the polyfunctional acrylate and the monofunctional acrylate to obtain a mixed resin;

[0020] (b) According to the mass ratio, mix the photoinitiator, the photosensitizer and the thermal initiator under light-shielding conditions to obtain an initiator;

[0021] (c) Mix the mixed resin and the initiator according to the ratio under light-shielding conditions to obtain the double-curing front polymerization resin system.

[0022] Preferably, the mixing method is to first perform ultrasonic oscillation and then perform mechanical stirring.

[0023] The usage method of the double-curing front polymerization resin system of the present invention is as follows:

[0024] For wind turbine blade defects below 10 layers, they can be repaired by the hand lay-up process, specifically as follows:

[0025] Grind and draw lines according to the structure of the defective area of the wind turbine blade; infiltrate the fiberglass cloth layer with a dual-curing front polymerization resin system; hand lay the infiltrated fiberglass cloth to the defective area according to the drawn line range; cover the release cloth on the surface of the outermost fiberglass cloth; turn on the ultraviolet lamp and cure for 3 minutes, then turn off the power supply; tear off the release cloth, and the repair is completed.

[0026] For wind turbine blade defects above 10 layers, they can be repaired by the vacuum infusion process, specifically as follows:

[0027] Grind and draw lines according to the structure of the defective area of the wind turbine blade; replenish the corresponding fiberglass cloth layer according to the drawn line range; lay the surface infusion auxiliaries (release cloth, flow guide net, runner, vacuum tape, vacuum film); connect and turn on the vacuum pump; vacuum infuse the dual-curing front polymerization resin system; turn on the ultraviolet lamp and cure for 3 minutes, then turn off; the surface cures and releases heat, and the reaction front moves in the thickness direction until curing is completed; turn off the vacuum pump and tear off the release cloth, and the repair is completed.

[0028] Compared with the prior art, the beneficial effects of the present invention at least include:

[0029] The dual-curing front polymerization resin system for repairing wind turbine blades in the present invention selects a photo-thermal dual-curing resin system to replace the original single thermal curing or photo-curing resin system, and at the same time compound raw materials such as photo-bleaching functional photoinitiators, thermal initiators, and high polymerization enthalpy monomers for front polymerization. Under simple ultraviolet light irradiation conditions, a polymerization reaction is initiated, and the heat of the polymerization reaction promotes the movement of the reaction front, realizing complete curing of thick-layer materials and colored systems without additional heat source equipment, with simple operation and environmental friendliness.

[0030] For the repair of areas with a curing depth less than 5 mm by the dual-curing front polymerization resin system for repairing wind turbine blades in the present invention, only photo-curing can meet the repair requirements. Even if there are areas with a curing depth greater than 5 mm, they can fully react in the form of thermal curing under the reaction heat with the promotion of the reaction front, solving the problems of limited application range of ordinary photo-curing resins, high energy consumption of thermal curing resins, and complex equipment. Detailed Embodiments

[0031] The embodiments of the technical solutions of the present invention will be described in detail below in conjunction with the embodiments. The following embodiments are only used to illustrate the technical solutions of the present invention more clearly, so they are only examples and cannot be used to limit the protection scope of the present invention.

[0032] It should be noted that unless otherwise specified, the technical terms or scientific terms used in this application should have the ordinary meanings understood by those skilled in the art to which the present invention belongs.

[0033] Example 1

[0034] This example is a dual-curing front polymerization resin system for the repair of fan blades. The dual-curing front polymerization resin system is composed of a mixed resin and an initiator, and the mass ratio of the initiator to the mixed resin is 1:100;

[0035] The mixed resin includes the following components in parts by weight:

[0036] 80 parts of epoxy resin, 12 parts of polyfunctional acrylate, and 8 parts of monofunctional acrylate. Among them, the epoxy resin is 3,4'-epoxycyclohexylmethyl 3,4'-epoxycyclohexanecarboxylate; the polyfunctional acrylate is composed of difunctional acrylate, trifunctional acrylate, and tetrafunctional acrylate with a mass ratio of 2:10:4; the difunctional acrylate is 1,6-hexanediol diacrylate; the trifunctional acrylate is trimethylolpropane triacrylate; the tetrafunctional acrylate is di(trimethylolpropane) tetraacrylate; the monofunctional acrylate is isobutyl acrylate;

[0037] The initiator includes a photoinitiator, a photosensitizer, and a thermal initiator. The mass ratio of the photoinitiator, photosensitizer, and thermal initiator is 4:1:2. Among them, the photoinitiator is bis(4-dodecylphenyl) iodonium hexafluoroantimonate; the photosensitizer is 2-isopropylthioxanthone; the thermal initiator is azobisisobutyronitrile.

[0038] The preparation method of the above dual-curing front polymerization resin system is characterized in that the preparation method includes the following steps:

[0039] (a) According to the parts by weight, mix epoxy resin, polyfunctional acrylate, and monofunctional acrylate, perform ultrasonic oscillation, and then stir at 300 r / min for 30 min to obtain a mixed resin;

[0040] (b) According to the mass ratio, mix the photoinitiator, photosensitizer, and thermal initiator under light-shielded conditions, perform ultrasonic oscillation, and then stir at 300 r / min for 15 min to obtain an initiator;

[0041] (c) According to the ratio, mix the mixed resin and the initiator under light-shielded conditions, perform ultrasonic oscillation, and then stir at 300 r / min for 10 min to obtain the dual-curing front polymerization resin system.

[0042] Example 2

[0043] This embodiment is a dual-curing frontline polymerization resin system for repairing fan blades. The dual-curing frontline polymerization resin system is composed of a mixed resin and an initiator, and the mass ratio of the initiator to the mixed resin is 2:100;

[0044] The mixed resin comprises the following components in parts by weight:

[0045] 90 parts of epoxy resin, 8 parts of polyfunctional acrylate, and 2 parts of monofunctional acrylate. Among them, the epoxy resin is 3,4'-epoxycyclohexylmethyl 3,4'-epoxycyclohexanecarboxylate; the polyfunctional acrylate is composed of a difunctional acrylate, a trifunctional acrylate, and a tetrafunctional acrylate with a mass ratio of 4:6:6; the difunctional acrylate is 1,6-hexanediol diacrylate; the trifunctional acrylate is trimethylolpropane triacrylate; the tetrafunctional acrylate is bis(trimethylolpropane) tetraacrylate; the monofunctional acrylate is isobornyl acrylate;

[0046] The initiator comprises a photoinitiator, a photosensitizer, and a thermal initiator. The mass ratio of the photoinitiator, the photosensitizer, and the thermal initiator is 6:1:3. Among them, the photoinitiator is bis(4-dodecylphenyl) iodonium hexafluoroantimonate; the photosensitizer is 2-isopropylthioxanthone; the thermal initiator is benzoyl peroxide.

[0047] The preparation method of the above dual-curing frontline polymerization resin system is characterized in that the preparation method comprises the following steps:

[0048] (a) According to the parts by weight, mix the epoxy resin, the polyfunctional acrylate, and the monofunctional acrylate, perform ultrasonic oscillation, and then stir at 300 r / min for 30 min to obtain a mixed resin;

[0049] (b) According to the mass ratio, mix the photoinitiator, the photosensitizer, and the thermal initiator under light-shielded conditions, perform ultrasonic oscillation, and then stir at 300 r / min for 15 min to obtain an initiator;

[0050] (c) According to the ratio, mix the mixed resin and the initiator under light-shielded conditions, perform ultrasonic oscillation, and then stir at 300 r / min for 10 min to obtain the dual-curing frontline polymerization resin system.

[0051] Example 3

[0052] This embodiment is a dual-curing frontline polymerization resin system for repairing fan blades. The dual-curing frontline polymerization resin system is composed of a mixed resin and an initiator, and the mass ratio of the initiator to the mixed resin is 1.5:100;

[0053] The mixed resin comprises the following components in parts by weight:

[0054] 85 parts of epoxy resin, 10 parts of polyfunctional acrylate and 5 parts of monofunctional acrylate, wherein the epoxy resin is 3,4'-epoxycyclohexylmethyl 3,4'-epoxycyclohexanecarboxylate; the polyfunctional acrylate is composed of a difunctional acrylate, a trifunctional acrylate and a tetrafunctional acrylate with a mass ratio of 3:8:5; the difunctional acrylate is 1,6-hexanediol diacrylate; the trifunctional acrylate is trimethylolpropane triacrylate; the tetrafunctional acrylate is bis(trimethylolpropane) tetraacrylate; the monofunctional acrylate is isobornyl acrylate;

[0055] The initiator includes a photoinitiator, a photosensitizer and a thermal initiator, and the mass ratio of the photoinitiator, the photosensitizer and the thermal initiator is 5:1:2.5, wherein the photoinitiator is bis(4-dodecylphenyl)iodonium hexafluoroantimonate; the photosensitizer is 2-isopropylthioxanthone; the thermal initiator is 1,1-di-tert-butylperoxycyclohexane.

[0056] The preparation method of the above double-curing front polymerization resin system is characterized in that the preparation method includes the following steps:

[0057] (a) According to parts by weight, mix the epoxy resin, polyfunctional acrylate and monofunctional acrylate, perform ultrasonic oscillation, and then stir at 300 r / min for 30 min to obtain a mixed resin;

[0058] (b) According to the mass ratio, mix the photoinitiator, photosensitizer and thermal initiator under light-shielded conditions, perform ultrasonic oscillation, and then stir at 300 r / min for 15 min to obtain an initiator;

[0059] (c) According to the ratio, mix the mixed resin and the initiator under light-shielded conditions, perform ultrasonic oscillation, and then stir at 300 r / min for 10 min to obtain the double-curing front polymerization resin system.

[0060] Comparative Example 1

[0061] This comparative example is a double-curing front polymerization resin system for repairing fan blades. The double-curing front polymerization resin system is composed of a mixed resin and an initiator, and the mass ratio of the initiator to the mixed resin is 1.5:100;

[0062] The mixed resin includes the following components in parts by weight:

[0063] 85 parts of epoxy resin, 10 parts of polyfunctional acrylate, and 5 parts of monofunctional acrylate, wherein the epoxy resin is 3,4'-epoxycyclohexylmethyl 3,4'-epoxycyclohexanecarboxylate; the polyfunctional acrylate is a trifunctional acrylate; the trifunctional acrylate is trimethylolpropane triacrylate; the monofunctional acrylate is isobornyl acrylate;

[0064] The initiator comprises a photoinitiator, a photosensitizer and a thermal initiator, and the mass ratio of the photoinitiator, the photosensitizer and the thermal initiator is 5:1:2.5, wherein the photoinitiator is bis(4-dodecylphenyl)iodonium hexafluoroantimonate; the photosensitizer is 2-isopropylthioxanthone; the thermal initiator is 1,1-di-tert-butylperoxycyclohexane.

[0065] The preparation method of the above double-curing front polymerization resin system is characterized in that the preparation method comprises the following steps:

[0066] (a) According to parts by weight, mix epoxy resin, polyfunctional acrylate and monofunctional acrylate, perform ultrasonic oscillation, and then stir at 300 r / min for 30 min to obtain a mixed resin;

[0067] (b) According to the mass ratio, mix the photoinitiator, the photosensitizer and the thermal initiator under light-shielded conditions, perform ultrasonic oscillation, and then stir at 300 r / min for 15 min to obtain an initiator;

[0068] (c) According to the ratio, mix the mixed resin and the initiator under light-shielded conditions, perform ultrasonic oscillation, and then stir at 300 r / min for 10 min to obtain the double-curing front polymerization resin system.

[0069] Comparative Example 2

[0070] This comparative example is a double-curing front polymerization resin system for repairing fan blades. The double-curing front polymerization resin system is composed of a mixed resin and an initiator, and the mass ratio of the initiator to the mixed resin is 1.5:100;

[0071] The mixed resin comprises the following components in parts by weight:

[0072] 85 parts of epoxy resin, 10 parts of polyfunctional acrylate, and 5 parts of monofunctional acrylate, wherein the epoxy resin is 3,4'-epoxycyclohexylmethyl 3,4'-epoxycyclohexanecarboxylate; the polyfunctional acrylate is composed of a trifunctional acrylate and a tetrafunctional acrylate with a mass ratio of 1:1; the trifunctional acrylate is trimethylolpropane triacrylate; the tetrafunctional acrylate is bis(trimethylolpropane) tetraacrylate; the monofunctional acrylate is isobornyl acrylate;

[0073] The initiator comprises a photoinitiator, a photosensitizer and a thermal initiator, and the mass ratio of the photoinitiator, the photosensitizer and the thermal initiator is 5:1:2.5. Among them, the photoinitiator is bis(4-dodecylphenyl)iodonium hexafluoroantimonate; the photosensitizer is 2-isopropylthioxanthone; and the thermal initiator is 1,1-di-tert-butylperoxycyclohexane.

[0074] The preparation method of the above double-curing front polymerization resin system is characterized in that the preparation method comprises the following steps:

[0075] (a) According to parts by weight, mix epoxy resin, polyfunctional acrylate and monofunctional acrylate, perform ultrasonic oscillation, and then stir at 300 r / min for 30 min to obtain a mixed resin;

[0076] (b) According to the mass ratio, mix the photoinitiator, the photosensitizer and the thermal initiator under light-shielded conditions, perform ultrasonic oscillation, and then stir at 300 r / min for 15 min to obtain an initiator;

[0077] (c) According to the ratio, mix the mixed resin and the initiator under light-shielded conditions, perform ultrasonic oscillation, and then stir at 300 r / min for 10 min to obtain the double-curing front polymerization resin system.

[0078] Comparative Example 3

[0079] This comparative example is a double-curing front polymerization resin system for repairing fan blades. The double-curing front polymerization resin system is composed of a mixed resin and an initiator, and the mass ratio of the initiator to the mixed resin is 1.5:100;

[0080] The mixed resin comprises the following components in parts by weight:

[0081] 85 parts of epoxy resin, 10 parts of polyfunctional acrylate and 5 parts of monofunctional acrylate. Among them, the epoxy resin is 3,4'-epoxycyclohexylmethyl 3,4'-epoxycyclohexanecarboxylate; the polyfunctional acrylate is composed of a tetrafunctional acrylate; the tetrafunctional acrylate is di(trimetylolpropane) tetraacrylate; and the monofunctional acrylate is isobornyl acrylate;

[0082] The initiator comprises a photoinitiator, a photosensitizer and a thermal initiator, and the mass ratio of the photoinitiator, the photosensitizer and the thermal initiator is 5:1:2.5. Among them, the photoinitiator is bis(4-dodecylphenyl)iodonium hexafluoroantimonate; the photosensitizer is 2-isopropylthioxanthone; and the thermal initiator is 1,1-di-tert-butylperoxycyclohexane.

[0083] The preparation method of the above double-curing front polymerization resin system is characterized in that the preparation method comprises the following steps:

[0084] (a) By weight, epoxy resin, polyfunctional acrylate, and monofunctional acrylate are mixed, ultrasonically oscillated, and then stirred at 300 r / min for 30 min to obtain a mixed resin;

[0085] (b) By mass ratio, a photoinitiator, a photosensitizer, and a thermal initiator are mixed under light-shielded conditions, ultrasonically oscillated, and then stirred at 300 r / min for 15 min to obtain an initiator;

[0086] (c) In proportion, the mixed resin and the initiator are mixed under light-shielded conditions, ultrasonically oscillated, and then stirred at 300 r / min for 10 min to obtain the dual-curing front polymerization resin system.

[0087] Experimental Example

[0088] The dual-curing front polymerization resin systems of Example 3 and Comparative Examples 1-3 are obtained respectively;

[0089] A stepped distribution thermocouple is used to measure the temperature of the photoinitiated polymerization front;

[0090] The density method is used to calculate the volume shrinkage rate under different component configurations;

[0091] A differential scanning calorimeter is used to test the glass transition temperature with reference to ISO 11357-2;

[0092] A universal tensile testing machine is used to test the tensile and flexural property parameters of the resin casting with reference to GB / T2567;

[0093] The test results are shown in Table 1;

[0094] Table 1

[0095]

[0096]

[0097] As can be seen from Table 1:

[0098] The addition of trimethylolpropane triacrylate can effectively increase the temperature of the polymerization front. The addition of di-(trimethylolpropane) tetraacrylate increases the crosslinking density and the glass transition temperature, but the volume shrinkage rate increases and the tensile and flexural properties decline. The addition of 1,6-hexanediol diacrylate introduces a flexible chain for toughening, improving the tensile and flexural strengths of the product, reducing the volume shrinkage rate and the glass transition temperature of the product, and meeting the basic requirements of the hand lay-up resin for wind turbine blade repair.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered by the scope of the claims and the specification of the present invention.

Claims

1. A dual-curing frontal polymerization resin system for wind turbine blade repair, characterized in that, The dual-curing front polymerization resin system is composed of a mixed resin and an initiator; The mixed resin comprises the following components in parts by weight: 80-90 parts of epoxy resin, 8-12 parts of polyfunctional acrylate, and 2-8 parts of monofunctional acrylate; the polyfunctional acrylate is composed of difunctional acrylate, trifunctional acrylate, and tetrafunctional acrylate; The initiator is composed of a photoinitiator, a photosensitizer, and a thermal initiator, and the mass ratio of the photoinitiator, the photosensitizer, and the thermal initiator is (4-6):1:(2-3).

2. The dual-curing front polymerization resin system according to claim 1, characterized in that, The mass ratio of the initiator to the mixed resin is (1-2):

100.

3. The dual-curing front polymerization resin system according to claim 1, wherein The epoxy resin is 3,4'-epoxycyclohexylmethyl 3,4'-epoxycyclohexanecarboxylate.

4. The dual-curing front polymerization resin system according to claim 1, characterized in that, The mass ratio of the difunctional acrylate, the trifunctional acrylate, and the tetrafunctional acrylate is (2-4):(6-10):(4-6); the difunctional acrylate is 1,6-hexanediol diacrylate; the trifunctional acrylate is trimethylolpropane triacrylate; the tetrafunctional acrylate is di(trimethylolpropane) tetraacrylate.

5. The dual-curing front polymerization resin system according to claim 1, wherein The monofunctional acrylate is isobutyl acrylate and / or isobornyl acrylate.

6. The dual-curing front polymerization resin system according to claim 1, characterized in that The photoinitiator is a cationic photoinitiator, and the cationic photoinitiator is diaryliodonium salt or triarylsulfonium salt.

7. The dual-curing front polymerization resin system according to claim 1, characterized in that, The photosensitizer is 2-isopropylthioxanthone.

8. The dual-curing front polymerization resin system according to claim 1, wherein, The thermal initiator is at least one of azobisisobutyronitrile, benzoyl peroxide, and 1,1-di-tert-butylperoxycyclohexane.

9. A method for preparing the dual-curing front polymerization resin system according to any one of claims 1 to 8, characterized in that, The preparation method comprises the following steps: (a) Mix epoxy resin, polyfunctional acrylate, and monofunctional acrylate in parts by weight to obtain a mixed resin; (b) Mix the photoinitiator, the photosensitizer, and the thermal initiator in the dark in accordance with the mass ratio to obtain an initiator; (c) Mix the mixed resin and the initiator in the dark in accordance with the ratio to obtain the dual-curing front polymerization resin system.

10. The preparation method according to claim 9, characterized in that, The mixing method is to first perform ultrasonic oscillation and then mechanical stirring.

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