Unsaturated resin and preparation method and application thereof

Abstract

The present invention discloses an unsaturated resin and a preparation method and application thereof, and belongs to the field of synthesis of unsaturated polyester resin and preparation of fiber-reinforced composite materials. The method comprises: step one, reacting saturated macromolecular unit alcohol with maleic anhydride at 80-140°C under the action of a catalyst for 2 hours to obtain an unsaturated macromolecular carboxylic acid; step two, preparing an unsaturated resin based on the product of step one; step three, respectively using different processes to prepare fiber-reinforced composite materials. Although the resin and composite materials prepared by the present invention have a low covalent bond cross-linking density, the coordination bond density is very high. Although the coordination bond energy is lower than that of the covalent bond, the ultra-high coordination bond density is sufficient to make up for the defect of low covalent bond cross-linking density, which makes the resin and composite materials prepared by the present invention have greatly improved mechanical properties compared with thermoplastic materials, and comparable mechanical properties compared with traditional thermosetting materials.

Description

[0001] Unsaturated resin and preparation method and application thereof Technical Field

[0002] The invention belongs to the technical field of polymer synthesis, and particularly relates to an unsaturated resin and a preparation method and application thereof. Background Art

[0003] Fiber reinforced composite materials are made of reinforcing fiber materials and matrix polymer resins through different processes, compounding and impregnating, and solidifying under a certain temperature and pressure. This type of material has the advantages of light weight, high strength, corrosion resistance, and aging resistance. Over the years, it has been widely used in military industry, aerospace, wind power, transportation, construction, pipelines and other fields.

[0004] Composite materials have mainly used epoxy resin, vinyl resin, phenolic resin, unsaturated polyester resin and polyurethane resin as matrix resins in the development process over the past few decades. All of the above resin cured products are highly cross-linked thermosetting structures. High cross-linking degree can give resin cured products and fiber-reinforced composite materials excellent mechanical properties. At the same time, the disadvantage is that neither resin cured products nor composite materials have the ability to be processed and molded again, so that they can only be scrapped and treated as solid waste after being damaged or scrapped during application because they cannot be repaired or recycled. This not only greatly increases the social operating costs, but also puts pressure on environmental protection.

[0005] In recent years, some fiber-reinforced thermoplastic resin composite materials have been applied. Compared with traditional thermosetting resins, their advantage is that they have the ability to undergo secondary molding. When a product is scrapped due to damage or expiration in a certain application, it can still be used as raw material. After simple processing and secondary molding, it can continue to serve in application conditions with lower performance requirements. Their disadvantage is that their mechanical properties are significantly lower than those of traditional resins, which greatly limits their application areas. This is also the main reason why fiber-reinforced thermoplastic composites still account for a small proportion of the composite material field after years of development. Summary of the invention

[0006] In order to solve the technical problems existing in the above-mentioned background technology, the present invention provides an unsaturated resin and a preparation method and application thereof.

[0007] The present invention adopts the following technical scheme: a method for preparing an unsaturated resin, comprising the following steps:

[0008] Step 1: reacting a saturated macromolecular alcohol and maleic anhydride at 80-140° C. for 1.5-2.5 hours in the presence of a catalyst to obtain an unsaturated macromolecular carboxylic acid;

[0009] The structural formula of the unsaturated macromolecular carboxylic acid is shown below:

[0010]

[0011] Among them, R represents or or or ; R1 means ;

[0012] m, n, i and j represent , , , the number of

[0013] Step 2: prepare an unsaturated resin according to the following mass fraction ratio:

[0014] Unsaturated macromolecular carboxylic acid 25~75wt. parts

[0015] Reactive diluent 25~75wt.

[0016] Curing agent 0.5~3wt.

[0017] Accelerator 0.1~1wt.

[0018] Antioxidant 1~3wt.

[0019] Chelating agent 1~10wt. parts.

[0020] In a further embodiment, the saturated macromolecular unit alcohol is selected from one or a mixture of alkyl alcohol, polyethylene glycol unit ether, polypropylene glycol unit ether, polycaprolactone unit alcohol, polybutyrolactone unit alcohol.

[0021] In a further embodiment, the molecular weight of the saturated macromolecular monoalcohol is 130-3000 g / mol.

[0022] In a further embodiment, the catalyst is one or more of tetramethylammonium chloride, tetraethylammonium chloride, benzyltrimethylammonium chloride, benzyltriethylammonium chloride, tetramethylammonium bromide, tetraethylammonium bromide, benzyltrimethylammonium bromide, and benzyltriethylammonium bromide;

[0023] The added amount of the catalyst is 0.5% to 2% of the total amount of the saturated macromolecular alcohol, maleic anhydride and the catalyst.

[0024] In a further embodiment, the alkyl alcohol is a long-chain aliphatic alkyl alcohol having 8 to 30 carbon atoms.

[0025] In a further embodiment, the polyethylene glycol unit ether is a polymer unit alcohol prepared using a small molecule monohydric alcohol as an initiator, an alkali metal as a catalyst, and ethylene oxide as a ring-opening monomer;

[0026] In a further embodiment, the polypropylene glycol unit ether is a polymer unit alcohol prepared using a small molecule monohydric alcohol as an initiator, an alkali metal as a catalyst, and propylene oxide as a ring-opening monomer.

[0027] In a further embodiment, the polycaprolactone monoalcohol is a polymer monoalcohol prepared by using a small molecule monoalcohol as an initiator, an organic tin as a catalyst, and caprolactone as a ring-opening monomer.

[0028] In a further embodiment, the polybutyrolactone monoalcohol is a polymer monoalcohol prepared by using a small molecule monoalcohol as an initiator, an organic tin as a catalyst, and butyrolactone as a ring-opening monomer.

[0029] In a further embodiment, the reactive diluent is one or more of styrene, methylstyrene, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, vinyl pyrrolidone, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, and hydroxypropyl methacrylate.

[0030] In a further embodiment, the curing agent is one or more of azobisisobutyronitrile, azobisisoheptanenitrile, tert-butyl perbenzoate, benzoyl peroxide, isopropylbenzene hydroperoxide, tert-butyl hydroperoxide, and methyl ethyl ketone peroxide.

[0031] In a further embodiment, the promoter is one or more of cobalt isooctanoate, cobalt cyclohexaneate, copper isooctanoate, and copper cyclohexaneate.

[0032] In a further embodiment, the antioxidant is a hindered phenol antioxidant, selected from one or more of the commercially available brands Antioxidant 1010, Antioxidant 1076, and Antioxidant 3114.

[0033] In a further embodiment, the chelating agent is one or more of calcium oxide, calcium hydroxide, magnesium oxide, magnesium hydroxide, zinc oxide, zinc hydroxide, zinc chloride, ferric chloride, and ferric chloride.

[0034] An unsaturated resin is prepared by the above method.

[0035] An unsaturated resin as described above is used to prepare a fiber-reinforced composite material, and the preparation of the fiber-reinforced composite material includes at least the following processes: pultrusion, winding, SMC sheet compression molding, BMC mass compression molding, vacuum infusion, prepreg compression molding, or hand lay-up; the pultrusion, winding, SMC sheet compression molding, BMC mass compression molding, vacuum infusion, prepreg compression molding, or hand lay-up all have a heating process.

[0036] In a further embodiment, the fiber-reinforced composite material includes: one or more of glass fiber, carbon fiber, basalt fiber, aramid fiber, and ultra-high molecular weight polyethylene fiber.

[0037] Beneficial effects of the invention: The invention relates to the synthesis and preparation of an unsaturated resin, and the molding and processing of fiber-reinforced resin-based composite materials under different processes. Compared with the prior art, the invention has the following advantages:

[0038] (1) Excellent mechanical properties. Although the covalent bond crosslinking density of the resin and composite material prepared by the present invention is low, the coordination bond density is very high. Although the coordination bond energy is lower than that of the covalent bond, the ultra-high coordination bond density is sufficient to make up for the defect of low covalent bond crosslinking density. This makes the mechanical properties of the resin and composite material prepared by the present invention greatly improved compared with thermoplastic materials, and the mechanical properties are comparable to those of traditional thermosetting materials.

[0039] (2) The secondary molding processing performance is excellent. As the temperature of the resin and composite material prepared by the present invention increases, the coordination bonds gradually weaken until they disappear. At this time, the resin and composite material can be processed to be molded again. When the temperature drops to room temperature, the coordination bonds are generated again and the mechanical properties are restored.

[0040] (3) The resin is applicable to a wide range of products and processes. Similar to traditional epoxy resins, the resin prepared by the present invention can be used in a variety of composite material preparation processes. Compared with existing thermoplastic resins such as polyethylene, polypropylene, and nylon that can only be used for chopped fibers, the resin prepared by the present invention can be used for chopped fibers to prepare SMC sheets, BMC pellets, etc., and can also be used for continuous fibers to prepare pultruded profiles, winding pipes, vacuum infusion profiles, and prepreg molding. DETAILED DESCRIPTION

[0041] In order to solve the problems in the background technology, the present invention discloses a low cross-linking unsaturated resin with a chelating function, which has a low "carbon-carbon single bond" cross-linking degree and a high "carboxylic acid-metal" coordination bond cross-linking degree. The carbon-carbon single bond energy is stable and has nothing to do with temperature. Once it is damaged, it is difficult to form here. It is an irreversible chemical bond; the carboxylic acid-metal coordination bond energy gradually weakens with increasing temperature until it disappears, and can be formed again when the temperature is lowered. It is a reversible chemical bond. The lower "carbon-carbon single bond" cross-linking degree gives the resin cured product repairability and secondary molding ability at high temperatures, and the higher "carboxylic acid-metal" coordination bond cross-linking degree gives the resin mechanical properties comparable to thermosetting resins at room temperature.

[0042] The present invention will be further described below in conjunction with the examples, which are intended to explain the present invention and are not to be construed as limiting the present invention. Where specific techniques and reaction conditions are not specified in the examples, the techniques or conditions described in the literature in the art or the product instructions may be used. Any reagent, instrument or equipment not specified by the manufacturer may be obtained commercially.

[0043] Example 1

[0044] S1. Weigh 242 g of hexadecanol with a molecular weight of 242 g / mol, heat to 100 ° C, add 98 g of maleic anhydride, continue to add 1.7 g (total weight 0.5%) of tetramethylammonium bromide, stir and react for 2 hours to obtain an unsaturated macromolecular carboxylic acid monomer; the structure of the unsaturated macromolecular carboxylic acid monomer of this embodiment is as follows: , R represents , and the value of m in R1 is 15.

[0045] Further expressed as:

[0046] .

[0047] S2. Prepare unsaturated resin according to the following ratio

[0048] 75 wt. parts of unsaturated macromolecular carboxylic acid of the above structure

[0049] Styrene 25wt. parts

[0050] 0.5wt. parts of tert-butyl perbenzoate

[0051] Cobalt naphthenate 1wt.

[0052] Antioxidant 1010 3wt.

[0053] 10wt. parts of magnesium oxide

[0054] S3. Preparation of pultrusion board fiber reinforced composite materials:

[0055] 10 kg of unsaturated resin is prepared according to the above ratio and poured into an open glue tank. Driven by the traction device of the pultrusion equipment, the continuous glass fiber passes through the glue tank and is compounded and impregnated with the resin. It continues to pass through the high-temperature mold, solidify, demould, cool, cut and test.

[0056] Example 2

[0057] S1. Weigh 130 g of octanol (carbon number 8) with a molecular weight of 130 g / mol, heat to 80 ° C, add 98 g of maleic anhydride, continue to add 4.6 g (total weight 2%) of benzyltriethylammonium chloride, stir and react for 2 hours to obtain an unsaturated macromolecular carboxylic acid monomer; the structure of the saturated macromolecular carboxylic acid monomer in this embodiment is as follows:

[0058] , that is, in this embodiment, the value of m in R1 is 7.

[0059] S2. Prepare unsaturated resin according to the following ratio

[0060] 25wt. parts of the unsaturated macromolecular carboxylic acid of the above structure

[0061] 75wt. parts of vinyl pyrrolidone

[0062] 3wt. parts of methyl ethyl ketone peroxide

[0063] Copper 2-octanoate 0.1wt.

[0064] Antioxidant 1076 1wt.

[0065] Calcium oxide 1wt.

[0066] S3. Preparation of fiber-reinforced composite materials by vacuum infusion process: Prepare 10 kg of unsaturated resin according to the above proportions and stir evenly. Under the action of negative pressure, draw it into a vacuum mold with a heatable bottom and carbon fiber laid inside. Curing is achieved under high temperature and atmospheric pressure, and testing is carried out.

[0067] Example 3

[0068] S1. Weigh 438g of triacontanol (30 carbon atoms) with a molecular weight of 438g / mol, heat to 140°C, add 98g of maleic anhydride, continue to add 5.36g (1% of the total weight) of benzyltrimethylammonium bromide, stir and react for 2h to obtain an unsaturated macromolecular carboxylic acid monomer; the structural formula of the unsaturated macromolecular carboxylic acid monomer prepared in this embodiment is as follows:

[0069] , where the value of m in R1 is 29.

[0070] S2. Prepare unsaturated resin according to the following ratio:

[0071] 50wt. parts of unsaturated macromolecular carboxylic acid of the above structure

[0072] Hydroxyethyl acrylate 50wt. parts

[0073] 2.5wt. parts of benzoyl peroxide

[0074] 0.5wt. of cobalt 2-ethylhexanoate

[0075] Antioxidant 3114 1.5wt.

[0076] 6wt. parts of ferrous chloride.

[0077] S3. Preparation of Fiber Reinforced Composite Materials by Winding Process:

[0078] According to the above proportion, 10 kg of unsaturated resin was prepared and stirred evenly. The board was prepared on a small winding test equipment. The basalt fiber impregnated with resin was wrapped on a flat mold by a traction device, heated and cured, demolded and tested.

[0079] Example 4

[0080] S1. Weigh 3000g of polybutyrolactone unit alcohol with a molecular weight of 3000g / mol, heat to 120°C, add 98g of maleic anhydride, continue to add 3.18g (total weight 0.8%) of tetraethylammonium chloride, stir and react for 2h to obtain an unsaturated macromolecular carboxylic acid monomer; the structural formula of the unsaturated macromolecular carboxylic acid monomer prepared in this embodiment is as follows: , R represents , that is, m=3, n=34.5, which is expressed as: , n=34.5.

[0081] S2. Prepare unsaturated resin according to the following ratio:

[0082] 60 wt. parts of unsaturated macromolecular carboxylic acid of the above structure

[0083] 40wt. parts of vinyl pyrrolidone

[0084] Benzoyl peroxide 2wt.

[0085] 0.8wt. of cobalt 2-ethylhexanoate

[0086] Antioxidant 3114 1.8wt.

[0087] 4wt. parts of zinc hydroxide

[0088] S3. Preparation of BMC sheet fiber reinforced composite material: prepare 10 kg of unsaturated resin according to the above proportion and stir evenly, use sheet preparation process to mix the resin and short-cut aramid fiber evenly, pour into the heated flat mold, use molding equipment to increase the pressure, solidify the sheet in the mold, and test.

[0089] Example 5

[0090] S1. Weigh 2000g of polyethylene glycol monomethyl ether with a molecular weight of 2000g / mol, heat to 110°C, add 98g of maleic anhydride, continue to add 33.57g (total weight 1.6%) of tetramethylammonium chloride, stir and react for 2h to obtain an unsaturated macromolecular carboxylic acid monomer; the structural formula of the unsaturated macromolecular carboxylic acid monomer prepared in this embodiment is as follows: , that is, R represents , in this embodiment, j=44.7.

[0091] S2. Prepare unsaturated resin according to the following ratio

[0092] 65wt. parts of unsaturated macromolecular carboxylic acid of the above structure

[0093] 35wt. parts of hydroxypropyl methacrylate

[0094] 2.2wt. parts of tert-butyl hydroperoxide

[0095] Copper naphthenate 0.65wt.

[0096] Antioxidant 3114 1.8wt.

[0097] 4.5wt. parts of magnesium hydroxide

[0098] S3. Preparation of hand lay-up panels Fiber reinforced composite materials:

[0099] Prepare 10 kg of unsaturated resin according to the above ratio and stir evenly. Use hand-layup resin processing method to manually apply the resin on the glass fiber cloth with a brush, stack 2 layers, put it in an oven, heat and cure it, and test it.

[0100] Example 6

[0101] S1. Weigh 500 g of polypropylene glycol monomethyl ether with a molecular weight of 500 g / mol, heat to 130 ° C, add 98 g of maleic anhydride, continue to add 4.48 g (total weight 0.75%) of benzyltrimethylammonium chloride, stir and react for 2 hours to obtain an unsaturated macromolecular carboxylic acid monomer; the structural formula of the unsaturated macromolecular carboxylic acid monomer prepared in this embodiment is as follows: , that is, in this embodiment, R represents , and i=8.1.

[0102] S2. Prepare unsaturated resin according to the following ratio:

[0103] 45wt. parts of unsaturated macromolecular carboxylic acid having the above structure

[0104] Hydroxypropyl acrylate 55wt. parts

[0105] Cumene hydroperoxide 1.6wt.

[0106] Copper naphthenate 0.55wt.

[0107] Antioxidant 1076 1.2wt.

[0108] 3.5wt. parts of calcium hydroxide;

[0109] S3. Preparation of SMC sheets Fiber reinforced composite materials:

[0110] Prepare 10 kg of unsaturated resin according to the above proportions and stir evenly. Use sheet preparation technology to mix the resin and chopped carbon fiber evenly, pour it into a heated flat mold, use molding equipment to increase the pressure, solidify the sheet in the mold, and test.

[0111] Example 7

[0112] S1. Weigh 800 g of polycaprolactone monoalcohol with a molecular weight of 800 g / mol, heat to 90 ° C, add 98 g of maleic anhydride, continue to add 16.16 g (total weight 1.8%) of benzyltriethylammonium bromide, stir and react for 2 hours to obtain an unsaturated macromolecular carboxylic acid monomer; the structural formula of the macromolecular carboxylic acid monomer prepared in this embodiment is as follows: , R represents , that is, m=5, n=6.1, which is expressed as: , n=6.1.

[0113] S2. Prepare unsaturated resin according to the following ratio:

[0114] Unsaturated macromolecular carboxylic acid 70wt. parts

[0115] 30wt. parts of hydroxyethyl methacrylate

[0116] 2.1wt. parts of azobisisoheptanenitrile

[0117] Copper naphthenate 0.65wt.

[0118] Antioxidant 3114 1.7wt.

[0119] 3.5wt. parts of zinc hydroxide.

[0120] S3. Preparation of prepreg sheets Fiber reinforced composite materials:

[0121] Prepare 10 kg of unsaturated resin according to the above ratio and stir evenly. Use the prepreg preparation process to compound the resin and ultra-high molecular weight polyethylene fiber cloth and roll it. After the resin is thickened, place the prepreg in a heated flat mold, use molding equipment to increase the pressure, solidify the plate in the mold, and test it.

[0122] A method for preparing a fiber reinforced composite material according to step three of Example 1 to Example 7 is carried out using a conventional thermosetting resin, and other raw materials are the same as those in Example 1 to Example 7, to obtain Comparative Examples 1 to Comparative Examples 7.

[0123] Comparative Examples 8 to 11 are obtained by preparing the same-sized plates by hot pressing and melting molding using polyethylene composite chopped glass fiber particles, polypropylene composite chopped carbon fiber particles, nylon composite chopped basalt fiber particles, and polyoxymethylene composite chopped glass fiber particles.

[0124] The performance tests of Examples 1 to 7 and Comparative Examples 1 to 11 were performed to obtain the performance tests shown in the following table:

[0125] Test items Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Fiber content (%) 80 70 75 55 60 55 75 Tensile strength (MPa) 823 1654 703 532 557 527 744 Elongation at break (%) 8.2 8.6 8.5 10.1 9.0 9.6 8.3 Can secondary molding be performed? yes yes yes yes yes yes yes Test items Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Selected resin Phenolic Epoxy Unsaturated polyester Unsaturated polyester Vinyl Unsaturated polyester Epoxy Fiber content (%) 80 70 75 55 60 55 75 Tensile strength (MPa) 858 1669 720 535 588 547 755 Elongation at break (%) 3.5 4.4 4.8 5.1 5.1 5.2 5.5 Can secondary molding be performed? no no no no no no no Test items Comparative Example 8 Comparative Example 9 Comparative Example 10 Comparative Example 11 Selected resin Polyethylene Polypropylene nylon Paraformaldehyde Fiber content (%) 30 30 30 25 Tensile strength (MPa) 68 72 122 156 Elongation at break (%) 15.4 17.5 14.1 11.9 Can secondary molding be performed? yes yes yes yes

[0126] It can be seen from the above data that the unsaturated resin prepared by the present invention is suitable for a variety of processes. The boards prepared therefrom have similar mechanical properties to those of traditional resins, have higher elongation at break, and can be processed by secondary molding. Compared with boards made of thermoplastic particles, the mechanical properties are significantly improved.

[0127] In summary, compared with the conventional technology, the present invention has the following advantages: (1) The molecular structure of the resin solid has a low degree of crosslinking, which provides the resin solid and the fiber reinforced composite material with a strong ability to undergo a "solid-liquid" phase transition and re-molding at a certain temperature and / or pressure; (2) The resin solid itself has a large number of functional groups, and the fiber reinforced composite material can undergo a phase transition at a certain temperature and / or pressure, so that the damage to the fiber reinforced composite material during application can be repaired by high temperature and / or ultraviolet light "welding" through covalent bond linkage or molecular chain entanglement; (3) The presence of a large number of carboxylic acid functional groups can realize the formation of a large number of coordination bonds in the resin solid. The strength of this coordination bond is related to temperature. Crosslinking can be formed at low temperature to make the resin solid have strong mechanical properties. The coordination bonds disappear at high temperature, so that the resin solid has strong remolding performance.

Claims

1. A method for preparing an unsaturated resin, characterized in that: The following steps are involved: Step 1: reacting a saturated macromolecular alcohol and maleic anhydride at 80-140° C. under the action of a catalyst for 1.5-2.5 hours to obtain an unsaturated macromolecular carboxylic acid; The structural formula of the unsaturated macromolecular carboxylic acid is shown below Wherein, R represents R1-O- or R1 means m, i and j represent -CH2-, The amount of -CH2-CH2-O-; Step 2: prepare an unsaturated resin according to the following mass ratio: Unsaturated macromolecular carboxylic acid 25-75wt. parts Reactive diluent 25~75wt. parts Curing agent 0.5~3wt. Accelerator 0.1~1wt. Antioxidant 1~3wt. 1-10 wt. parts of chelating agent; The chelating agent is one or more of calcium oxide, calcium hydroxide, magnesium oxide, magnesium hydroxide, zinc oxide, zinc hydroxide, zinc chloride, ferric chloride, and ferric chloride; The saturated macromolecular unit alcohol is selected from one or a mixture of alkyl alcohol, polyethylene glycol unit ether, and polypropylene glycol unit ether; The molecular weight of the saturated macromolecular monoalcohol is 130 to 3000 g / mol; The accelerator is one or more of cobalt isooctanoate, cobalt naphthenate, copper isooctanoate and copper naphthenate.

2. The method for preparing an unsaturated resin according to claim 1, characterized in that: The catalyst is one or more of tetramethylammonium chloride, tetraethylammonium chloride, benzyltrimethylammonium chloride, benzyltriethylammonium chloride, tetramethylammonium bromide, tetraethylammonium bromide, benzyltrimethylammonium bromide and benzyltriethylammonium bromide; The added amount of the catalyst is 0.5% to 2% of the total amount of the saturated macromolecular unit alcohol, maleic anhydride and the catalyst.

3. The method for preparing an unsaturated resin according to claim 1, characterized in that: The alkyl alcohol is a long-chain aliphatic alkyl alcohol having 8 to 30 carbon atoms.

4. The method for preparing an unsaturated resin according to claim 1, characterized in that: The polyethylene glycol unit ether is a polymer unit alcohol prepared by using a small molecule monohydric alcohol as an initiator, an alkali metal as a catalyst, and ethylene oxide as a ring-opening monomer.

5. The method for preparing an unsaturated resin according to claim 1, characterized in that: The polypropylene glycol unit ether is a polymer unit alcohol prepared by using a small molecule monohydric alcohol as an initiator, an alkali metal as a catalyst, and propylene oxide as a ring-opening monomer.

6. The method for preparing an unsaturated resin according to claim 1, characterized in that: The reactive diluent is one or more of styrene, methylstyrene, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, vinyl pyrrolidone, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, and hydroxypropyl methacrylate.

7. The method for preparing an unsaturated resin according to claim 1, characterized in that: The curing agent is one or more of azobisisobutyronitrile, azobisisoheptanenitrile, tert-butyl perbenzoate, benzoyl peroxide, isopropylbenzene hydroperoxide, tert-butyl hydroperoxide, and methyl ethyl ketone peroxide.

8. The method for preparing an unsaturated resin according to claim 1, characterized in that: The antioxidant is a hindered phenol antioxidant.

9. An unsaturated resin, characterized in that Prepared by the method according to any one of claims 1 to 8.

10. The unsaturated resin according to claim 9 is used for preparing fiber-reinforced composite materials, characterized in that: The preparation of the fiber reinforced composite material includes at least the following processes: pultrusion, winding, SMC sheet compression molding, BMC mass compression molding, vacuum infusion, prepreg compression molding, or hand lay-up; the pultrusion, winding, SMC sheet compression molding, BMC mass compression molding, vacuum infusion, prepreg compression molding, or hand lay-up all have a heating process.

11. The unsaturated resin according to claim 10 is used to prepare a fiber-reinforced composite material, characterized in that: The fiber-reinforced composite material includes: one or more of glass fiber, carbon fiber, basalt fiber, aramid fiber, and ultra-high molecular weight polyethylene fiber.

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