Degradable resin material for wind power blade and preparation method thereof
By introducing conjugated double bonds and thiol functional groups into the vinyl ester resin to form a three-layer crosslinking structure, the problem of difficult recovery and degradation of thermosetting composite materials on wind power blades is solved, and a degradable resin material with high mechanical properties and high recycling rate is achieved.
Patent Information
- Application Number
- CN202411632434.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-15
- Publication Date
- 2025-03-04
AI Technical Summary
The thermosetting composite materials of existing wind power blades are difficult to effectively recycle and degrade, resulting in reduced performance of recycled materials, high energy consumption, high pollution, and unclear resin degradation mechanism, which cannot guide the design of recyclable degradable resins.
By introducing conjugated double bonds into the vinyl ester resin, a six-membered ring structure is formed by using Diels-Alder reaction, and excessive thiol functional groups are introduced, and a three-layer crosslinked structure is formed through thiol-ene photopolymerization reaction and thiol self-oxidation, and a degradable resin material is prepared.
The prepared resin material has excellent mechanical properties and can be reversely disassembled by reducing agent, with a high recycling rate, which solves the problems of poor recycling performance and high energy consumption in the prior art.
Smart Images
Figure CN119552320A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of polymer preparation, and in particular to a degradable resin material for wind turbine blades and a preparation method thereof. Background Art
[0002] In 2023, the total installed capacity of wind and solar power in China has exceeded 1 billion kilowatts, and its dominant position in the newly installed power capacity has been further consolidated. With the rise of new energy sources such as wind power, the environmental protection issues caused by the retirement of wind turbine blades have become an important issue in the current new energy field, and the recycling and utilization of wind turbine blades has become an urgent problem to be solved. According to professional organizations, my country will usher in a peak period of wind turbine retirement from 2025. It is estimated that by 2030, a total of more than 30,000 units will reach retirement age, with a retired installed capacity of 44.73 million kilowatts, and the resulting solid waste will reach 947,900 tons. What to do with retired wind turbines has become a threshold that must be overcome for the development of my country's wind power industry.
[0003] Existing wind turbine blades generally use typical thermosetting composite materials. Since the structure of thermosetting resins is very stable, they generally require high-temperature treatment to decompose. The main methods have pain points such as serious reduction in recycled material performance, high recycling energy consumption, and high pollution. Therefore, it is not easy to use them to process large components such as blades. At the same time, the resin degradation mechanism in the existing technology is unclear and cannot provide a good guide for the design of recyclable resins for wind turbine blades.
[0004] Therefore, it is an urgent problem to be solved at present to design a series of recyclable and degradable resins for wind turbine blades and analyze the degradation mechanism to provide guidance for designing recyclable and degradable resins for wind turbine blades. Summary of the invention
[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a degradable resin material for wind turbine blades and a preparation method thereof. By introducing conjugated double bonds into vinyl ester resin, a first layer of cross-linked six-membered ring structure is formed in the vinyl ester resin system by utilizing the Diels-Alder reaction, and an excess of thiol functional groups are further introduced. The newly generated double bonds further form a second layer of cross-linked structure through thiol-ene photopolymerization reaction, and a third layer of cross-linked structure is formed through thiol self-oxidation, so that the prepared resin material has excellent mechanical properties, and the resin material can be reversely disassembled by a reducing agent, and has a high recycling rate.
[0006] To achieve the above object, the present invention provides the following technical solutions:
[0007] A method for preparing a degradable resin material for a wind turbine blade comprises the following steps:
[0008] S1. Under nitrogen protection and magnetic stirring, 40-60 parts of vinyl ester resin, 20-30 parts of alkyl methacrylate and 3-4 parts of aluminum chloride are mixed by mass, and the temperature is raised to 60-70 ° C for prepolymerization for 3-4h to form a first polymerization network to obtain a prepolymer;
[0009] S2. Mix 20-40 parts of the prepolymer prepared in S1 with 20-30 parts of pentaerythritol tetrakis-3-mercaptopropionate and 5-7 parts of a photoinitiator by mass, and initiate a thiol-ene photopolymerization reaction under ultraviolet light irradiation. After reacting for 0.5-1h, add 8-10 parts of triethylamine, and heat to 150-160°C for curing for 1-2h to form a second polymerization network to obtain a primary polymer;
[0010] S3. Mix 20-30 parts of the primary polymer with 6-8 parts of an oxidant by mass, adjust the pH to 8-9, and cure at 60-70° C. for 1-2 hours to form a third polymer network to obtain the degradable resin material.
[0011] Preferably, in step S1, the operating parameter of the magnetic stirring is 150-200 rpm.
[0012] Preferably, the vinyl ester resin is further defined as bisphenol A epoxy vinyl resin.
[0013] Preferably, the alkyl methacrylate is selected from one or more of methyl methacrylate, ethyl methacrylate and propyl methacrylate.
[0014] Preferably, in step S2, the photoinitiator is selected from one or more of 1-hydroxycyclohexyl phenyl ketone, 2-methyl-2-(4-morpholinyl)-1-[4-(methylthio)phenyl]-1-propanone, and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.
[0015] Preferably, in step S2, the operating parameters of the ultraviolet light irradiation are 300-500 mW / cm 2 .
[0016] Preferably, in step S3, the oxidant is selected from one or more of ammonium persulfate, potassium persulfate, ferric chloride, and hydrogen peroxide.
[0017] A degradable resin material for wind turbine blades is prepared according to the preparation method.
[0018] Compared with the prior art, the present invention has the following beneficial effects:
[0019] 1. The present invention introduces conjugated double bonds into the vinyl ester resin, forms a first-layer cross-linked six-membered ring structure in the vinyl ester resin system by using the Diels-Alder reaction, and further introduces excess thiol functional groups. The newly generated double bonds further form a second-layer cross-linked structure through thiol-ene photopolymerization reaction, and form a third-layer cross-linked structure through thiol self-oxidation, so that the prepared resin material has excellent mechanical properties, and the resin material can be reversely disassembled by a reducing agent, and has a high recycling rate;
[0020] 2. The preparation process of the present invention is simple, the reaction conditions are mild, the requirements for production equipment are low, large-scale production can be carried out, and it has obvious economic value. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 The present invention is a flow chart of the preparation process of the degradable resin material. DETAILED DESCRIPTION
[0022] The present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0023] See also Figure 1 , the present invention provides a technical solution:
[0024] Example 1
[0025] A method for preparing a degradable resin material for wind turbine blades:
[0026] S1. Under nitrogen protection and magnetic stirring at 150 rpm, 40 g of vinyl ester resin was mixed with 20 g of alkyl methacrylate and 3 g of aluminum chloride, and the temperature was raised to 60 ° C for prepolymerization for 3 h to form a first polymerization network to obtain a prepolymer;
[0027] S2. 20 g of the prepolymer prepared in S1 was mixed with 20 g of pentaerythritol tetrakis-3-mercaptopropionate and 5 g of photoinitiator and stirred at 300 mW / cm 2 Under ultraviolet irradiation conditions, thiol-ene photopolymerization reaction was initiated, and after the reaction for 0.5 h, 8 g of triethylamine was added, and the temperature was raised to 150° C. and cured for 1 h to form a second polymerization network to obtain a primary polymer;
[0028] S3. Mix 20 g of the primary polymer with 6 g of an oxidant, adjust the pH to 8, and cure at 60° C. for 1 h to form a third polymer network to obtain the degradable resin material.
[0029] In the above process, the vinyl ester resin is bisphenol A epoxy vinyl resin with the brand name Derakane 411; the alkyl methacrylate is methyl methacrylate; the photoinitiator is 1-hydroxycyclohexyl phenyl ketone; and the oxidant is ammonium persulfate.
[0030] Example 2
[0031] A method for preparing a degradable resin material for wind turbine blades:
[0032] S1. Under nitrogen protection and magnetic stirring at 200 rpm, 60 g of vinyl ester resin was mixed with 30 g of alkyl methacrylate and 3 g of aluminum chloride, and the temperature was raised to 70 ° C for prepolymerization for 3 h to form a first polymerization network to obtain a prepolymer;
[0033] S2. 30 g of the prepolymer prepared in S1 was mixed with 30 g of pentaerythritol tetrakis-3-mercaptopropionate and 5 g of photoinitiator at 400 mW / cm 2 Under ultraviolet irradiation conditions, a thiol-ene photopolymerization reaction was initiated. After the reaction for 0.75 h, 8 g of triethylamine was added, and the temperature was raised to 160° C. for curing for 1.5 h to form a second polymerization network, thereby obtaining a primary polymer.
[0034] S3. 30 g of the primary polymer was mixed with 8 g of an oxidant, the pH was adjusted to 8, and the mixture was cured at 70° C. for 1.5 h to form a third polymer network, thereby obtaining the degradable resin material.
[0035] In the above process, the vinyl ester resin is bisphenol A epoxy vinyl resin with the brand name Derakane 411; the alkyl methacrylate is ethyl methacrylate; the photoinitiator is 2,4,6-trimethylbenzoyl-diphenylphosphine oxide; and the oxidant is potassium persulfate.
[0036] Example 3
[0037] A method for preparing a degradable resin material for wind turbine blades:
[0038] S1. Under nitrogen protection and magnetic stirring at 200 rpm, 55 g of vinyl ester resin was mixed with 25 g of alkyl methacrylate and 3 g of aluminum chloride, and the temperature was raised to 65 ° C for prepolymerization for 3 h to form a first polymerization network to obtain a prepolymer;
[0039] S2. 35 g of the prepolymer prepared in S1 was mixed with 25 g of pentaerythritol tetrakis-3-mercaptopropionate and 5 g of photoinitiator at 400 mW / cm 2 Under ultraviolet irradiation conditions, a thiol-ene photopolymerization reaction was initiated. After the reaction for 1 hour, 8 g of triethylamine was added, and the temperature was raised to 155° C. for curing for 1.5 hours to form a second polymerization network, thereby obtaining a primary polymer;
[0040] S3. Mix 25 g of the primary polymer with 8 g of an oxidant, adjust the pH to 8, and cure at 65° C. for 1.5 h to form a third polymer network to obtain the degradable resin material.
[0041] In the above process, the vinyl ester resin is bisphenol A epoxy vinyl resin with the brand name Derakane 411; the alkyl methacrylate is propyl methacrylate; the photoinitiator is 2-methyl-2-(4-morpholinyl)-1-[4-(methylthio)phenyl]-1-propanone; and the oxidant is hydrogen peroxide.
[0042] Comparative Example
[0043] Comparative Example 1: Comparative Example 1 is different from Example 1 in that step S3 originally existing in Example 1 is omitted in Comparative Example 1, thereby omitting the use of the oxidant, and the remaining steps are exactly the same in Comparative Example 1 and Example 1.
[0044] Comparative Example 2: Comparative Example 2 is different from Example 1 in that steps S2 and S3 originally existing in Example 1 are omitted in Comparative Example 2, thereby omitting the use of pentaerythritol tetrakis-3-mercaptopropionate and oxidant, and the remaining steps in Comparative Example 2 are exactly the same as those in Example 1.
[0045] Comparative Example 3: Standard bisphenol A epoxy vinyl resin (brand name Derakane 411) that has not been chemically modified is used as Comparative Example 3.
[0046] Performance Testing
[0047] Performance tests were performed on Examples 1-3 and Comparative Examples 1-3;
[0048] The viscosity, gel time, curing time, exothermic temperature peak and styrene content are tested according to the standard GB / T13657-2011;
[0049] The acid value is tested according to the standard GB / T2895-2008;
[0050] The tensile strength, tensile elastic modulus, elongation at break, flexural strength and flexural elastic modulus are tested in accordance with the standard GB / T2567-2008;
[0051] The heat deformation temperature is tested according to the standard GB / T1634-2004;
[0052] The Barcol hardness is tested according to the standard GB / T3854-2005.
[0053] The test results are as follows:
[0054]
[0055]
[0056] The degradation rate and recovery rate of Examples 1-3 and Comparative Examples 1-3 were tested. The test method was to crush the resin materials of Examples 1-3 and Comparative Examples 1-2 of the same mass, immerse 1 portion of the crushed resin material in 100 portions of 0.5 mol / L dithiothreitol, heat to 60° C. and react for 12 hours, then add 20 portions of N-bromosuccinimide and react for 12 hours, filter and separate the degradation products, and test the degradation rate and recovery rate. The results are as follows:
[0057] project Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Degradation rate % 81.5 87.6 84.3 70.6 60.3 54.6 Recovery rate % 88.7 92.1 90.9 87.4 74.2 72.4
[0058] Referring to the test data of the above-mentioned Examples 1-3 and Comparative Examples 1-3, it can be seen that the mechanical properties of the modified thermosetting resin prepared by the present invention are greatly improved. Taking the tensile strength as an example, the tensile strength of the modified resin prepared by the present invention is above 90 MPa, while the standard resin used in Comparative Example 3 is only 66 MPa, and the tensile strength of Comparative Examples 1-3 also shows a decreasing trend, which strongly proves the influence of the three-layer cross-linked structure formed by the present invention on the resin performance;
[0059] Further, referring to the difference in degradation rate and recovery rate between Examples 1-3 of the present application and Comparative Examples 1-3, the degradation rates of the modified resins prepared in the Examples of the present application are all above 80%, which strongly proves that the recovery rate of the present application is high and the economic benefits are obvious; the reason is that the present application introduces dynamic covalent bonds into the resin base, which have dynamic reversibility. Under the action of an external catalyst, the dynamic bonds will undergo reversible breakage, causing the cross-linking density of the polymer content to decrease, thereby realizing the disassembly of the thermosetting resin under mild conditions; while in the comparative examples, Comparative Example 3 has a degradation rate of only 54.6%, and the degradation rates of Comparative Examples 1-3 show a decreasing trend. This is due to the low content of the dynamic covalent bonds introduced, the third layer of cross-linking structure is not introduced in Comparative Example 1, and only one layer of cross-linking structure is introduced in Comparative Example 2.
[0060] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A method for preparing a degradable resin material for wind turbine blades, characterized in that: The following steps are involved: S1. Under nitrogen protection and magnetic stirring, 40-60 parts of vinyl ester resin, 20-30 parts of alkyl methacrylate and 3-4 parts of aluminum chloride are mixed by mass, and the temperature is raised to 60-70 ° C for prepolymerization for 3-4h to form a first polymerization network to obtain a prepolymer; S2. Mix 20-40 parts of the prepolymer prepared in S1 with 20-30 parts of pentaerythritol tetrakis-3-mercaptopropionate and 5-7 parts of a photoinitiator by mass, and initiate a thiol-ene photopolymerization reaction under ultraviolet light irradiation. After reacting for 0.5-1h, add 8-10 parts of triethylamine, and heat to 150-160°C for curing for 1-2h to form a second polymerization network to obtain a primary polymer; S3. Mix 20-30 parts of the primary polymer with 6-8 parts of an oxidant by mass, adjust the pH to 8-9, and cure at 60-70° C. for 1-2 hours to form a third polymer network to obtain the degradable resin material.
2. The method for preparing a degradable resin material for wind turbine blades according to claim 1, characterized in that: In step S1, the operating parameter of the magnetic stirring is 150-200 rpm.
3. The method for preparing a degradable resin material for wind turbine blades according to claim 1, characterized in that: The vinyl ester resin is further defined as bisphenol A epoxy vinyl resin.
4. The method for preparing a degradable resin material for wind turbine blades according to claim 1, characterized in that: The alkyl methacrylate is selected from one or more of methyl methacrylate, ethyl methacrylate and propyl methacrylate.
5. The method for preparing a degradable resin material for wind turbine blades according to claim 1, characterized in that: In step S2, the photoinitiator is selected from one or more of 1-hydroxycyclohexyl phenyl ketone, 2-methyl-2-(4-morpholinyl)-1-[4-(methylthio)phenyl]-1-propanone, and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.
6. The method for preparing a degradable resin material for wind turbine blades according to claim 1, characterized in that: In step S2, the working parameters of the ultraviolet light irradiation are 300-500mW / cm 2 .
7. The method for preparing a degradable resin material for wind turbine blades according to claim 1, characterized in that: In step S3, the oxidant is selected from one or more of ammonium persulfate, potassium persulfate, ferric chloride, and hydrogen peroxide.
8. A degradable resin material for wind turbine blades, characterized in that: Prepared according to any one of claims 1 to 7.