An epoxy resin toughener

Abstract

The application discloses an epoxy resin toughening agent. The toughening agent is a copolymer containing an epoxy group, the copolymer including one or more of structural unit I (flexible chain segment)-structural unit II (flexible chain segment), and one or more of structural unit III-structural unit XX (containing rigid structure). The toughening agent has an epoxy group in the molecular structure, so that the toughening agent molecule has good compatibility with the epoxy resin. Moreover, the toughening agent molecule has both flexible chain segments and rigid chain segments, so that the toughness and rigidity are considered. In addition, the imide ring exists in the toughening agent molecule, which can provide certain hydrophobicity and heat resistance. In summary, the toughening agent has excellent compatibility with the epoxy resin matrix, and is used for modifying the epoxy resin material, so that the original rigidity and heat resistance of the epoxy resin composite material are greatly retained on the premise of imparting good toughness to the epoxy resin composite material.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and in particular to an epoxy resin toughening agent. Background Technology

[0002] Epoxy resins possess excellent mechanochemical stability, heat and corrosion resistance, electrical insulation, and adhesive properties, making them one of the most widely used thermosetting materials. They are commonly used in anti-corrosion coatings, adhesives, semiconductor packaging materials, electrical insulation substances, and high-performance composite materials. However, cured epoxy resins exhibit a highly cross-linked structure, exhibiting almost no plastic deformation. Simultaneously, due to their low volume shrinkage rate, the internal stress generated during curing is also relatively small. However, the highly cross-linked rigid structure after curing results in poor impact resistance, severely limiting the applications of epoxy resins. Therefore, toughening epoxy resins has become a research hotspot.

[0003] Epoxy resin toughening systems can be classified into heterogeneous toughening mechanisms and homogeneous toughening mechanisms based on their toughening mechanisms. Epoxy resins toughened using heterogeneous toughening mechanisms typically have a multiphase structure with phase sizes at the submicron or micron level, exhibiting high toughness. However, the immiscibility between the resin matrix and the modifier leads to drawbacks such as high viscosity, opacity, and low flowability, thus limiting the application of epoxy resins in fields such as electronic packaging and wind power insulation coatings. Homogeneous toughening mechanisms, on the other hand, involve the modifier being uniformly dispersed in the epoxy matrix, forming an interpenetrating network of monomolecules or multimolecules within the crosslinked network. No second phase or phase separation occurs at the micro- or nanoscale, which can reduce the viscosity of the epoxy resin and has enormous application potential in advanced materials.

[0004] In homogeneous toughening mechanisms, flexible segment toughening primarily involves three methods: grafting flexible segments onto epoxy resin; curing epoxy resin with a curing agent containing flexible segments; and reducing the viscosity of epoxy resin using a flexible diluent. All three methods can reduce the crosslinking density of the cured system, forming a crosslinked network structure with alternating dense and sparse phases, which is beneficial for stress dispersion and thus achieves a toughening effect. However, these methods not only present challenges in raw material design and synthesis but also significantly reduce the heat resistance and tensile strength of the composite material. Furthermore, the uniformity of the flexible segments themselves is also a problem.

[0005] Therefore, it is essential to provide a toughening agent that is easy to synthesize and that slightly reduces or does not reduce the heat resistance and modulus of epoxy resin. Summary of the Invention

[0006] The purpose of this invention is to provide a low-cost, easy-to-prepare epoxy resin toughening agent that improves the toughness of epoxy resin while maintaining its high heat resistance and high rigidity, thereby solving the above-mentioned problems existing in the prior art.

[0007] To achieve the above objectives, the present invention provides the following solution:

[0008] One of the technical solutions of the present invention is: a toughening agent for epoxy resin, wherein the toughening agent is a copolymer containing epoxy groups, and the copolymer includes one or more of structural units I-II, and one or more of structural units III-XX.

[0009] , , , , , , , , , , , , , , , , , , , ;

[0010] Among them, R 1-4 R5 is independently selected from one of the following: hydrogen atom, alkyl group having 1-16 carbon atoms, and aryl group having 6-16 carbon atoms; R6 and R7 are independently selected from one of the following: hydrogen atom or methyl group; R8 is selected from one of the following: hydrogen atom, alkyl group having 1-17 carbon atoms; R9 is selected from one of the following: alkyl group having 2-10 carbon atoms, and aryl group having 6-13 carbon atoms.

[0011] Structural unit I contains four substituents R1-R4, each of which can be chosen in various ways. When each of the four substituents is selected as one of the substituents listed above, a specific structural unit is formed. Any change in any of the substituents can form another different structural unit. Therefore, structural unit I does not represent a single fixed structural unit, but rather multiple structural units that meet the above conditions. Similarly, structural units II through XX do not represent a single fixed structural unit, but rather multiple structural units that meet the above conditions. Thus, the copolymer comprising one or more of structural units I through II, and one or more of structural units III through XX, means including multiple structural units represented by structural unit I plus one or more of the multiple structural units represented by structural unit II, and multiple structural units represented by structural unit III plus multiple structural units represented by structural unit IV plus... plus one or more of the multiple structural units represented by structural unit XX.

[0012] Structural units I and II are flexible segments, while structural units III-XX contain an imide ring with a rigid structure. In addition to the imide ring, structural units III-XX also contain flexible segments R8 (when R8 is selected from alkyl groups with 2-17 carbon atoms) and R9. The presence of flexible segments can provide a good toughening effect on epoxy resin, while the introduced rigid structure can improve the rigidity of epoxy resin and maintain its heat resistance.

[0013] The second technical solution of the present invention: a method for preparing the above-mentioned toughening agent for epoxy resin, comprising the following steps: dissolving an electron-withdrawing monomer, an olefin monomer and an initiator in solvent A, and carrying out a polymerization reaction to obtain a copolymer; mixing the copolymer with an amine compound and carrying out an imidization reaction to obtain an imidized copolymer; mixing the imidized copolymer with an aldehyde compound, catalyst A and solvent B, and carrying out a hydroxylation reaction to obtain a hydroxylated copolymer; and selecting one of the following four methods to carry out an epoxidation reaction on the hydroxylated copolymer to obtain an epoxidized copolymer, which is the toughening agent for epoxy resin;

[0014] Method 1: The hydroxylated copolymer is mixed with an epoxy compound, catalyst B, catalyst C, and a non-epoxy solvent C to carry out an epoxidation reaction;

[0015] Method 2: The hydroxylated copolymer is mixed with an epoxy compound, catalyst B, and a non-epoxy solvent C to carry out an epoxidation reaction;

[0016] Method 3: The hydroxylated copolymer is mixed with catalyst B, catalyst C and epoxy solvent D to carry out an epoxidation reaction;

[0017] Method 4: Mix the hydroxylated copolymer with catalyst B and epoxy solvent D to carry out an epoxidation reaction.

[0018] Further, the electron-withdrawing monomer is one of maleic anhydride, itaconic anhydride, and their derivatives; the olefin monomer is one or more of chain olefins, cyclic olefins, aromatic olefins, conjugated dienes, and their derivatives having 2-18 carbon atoms; the initiator is one or more of peroxide initiators and azo initiators; the solvent A is one of organic acid alkyl esters, aromatic solvents, ether solvents, ketones, and alkanes; in the polymerization reaction system composed of the electron-withdrawing monomer, olefin monomer, initiator, and solvent A, the molar ratio of the electron-withdrawing monomer to the olefin monomer is 0.1-3:1, the sum of the mass of the electron-withdrawing monomer and the olefin monomer is 0.1-50% of the total mass of the polymerization reaction system, and the mass concentration of the initiator in the polymerization reaction system is 0.0001-5%; the polymerization reaction temperature is 40-120℃, and the time is 1-12h.

[0019] Further, the electron-withdrawing monomer is preferably maleic anhydride or itaconic anhydride; the olefin monomer is preferably one or more of the following: chain olefins having 2-18 carbon atoms, cyclic olefins having 5-8 carbon atoms, aromatic olefins having 8-14 carbon atoms, and conjugated dienes having 2-18 carbon atoms; more preferably, it is one or more of the following: α-olefins having 2-18 carbon atoms, cyclic olefins having 5-6 carbon atoms, and aromatic olefins having 8-9 carbon atoms.

[0020] Furthermore, there are no particular restrictions on the source of olefin monomers. One or more of the following can be used as raw materials for olefin monomers: petroleum fractions containing the above-mentioned olefin monomers (e.g., C4, C5 and C9 fractions), ethylene tar, methanol-to-olefins C4 and above by-product fractions, coal tar (e.g., dephenolized phenolic oil), and crude gasoline (e.g., pre-ether gasoline, post-ether gasoline, gasoline in gasoline hydrogenation, gasoline hydrogenation residue oil, etc.).

[0021] Further, the peroxide initiator includes one or more of benzoyl peroxide, dicumyl peroxide, cumyl hydroperoxide, ditert-butyl peroxide, dodecyl peroxide, and benzoic acid peroxide, preferably benzoyl peroxide; the azo initiator includes one or more of azobisisobutyronitrile, azobisisovalerate, azobisisoheptanenitrile, azoisobutylcyanoformamide, azobiscyclohexylformitrile, and dimethyl azobisisobutyrate, preferably one or more of azobisisobutyronitrile and azobisisoheptanenitrile.

[0022] Further, the organic acid alkyl ester includes one of ethyl formate, propyl formate, isobutyl formate, amyl formate, ethyl acetate, butyl acetate, isobutyl acetate, amyl acetate, isoamyl acetate, benzyl acetate, phenyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, butyl butyrate, isobutyl butyrate, isoamyl butyrate, ethyl isobutyrate, ethyl isovalerate, isoamyl isovalerate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, isoamyl benzoate, methyl phenylacetate, ethyl phenylacetate, propyl phenylacetate, butyl phenylacetate, and isoamyl phenylacetate, preferably one of ethyl acetate, butyl acetate, amyl acetate, and isoamyl acetate.

[0023] The aromatic solvent includes one of toluene, ethylbenzene, xylene, and cumene, preferably xylene; the ether solvent includes one of dimethyl ether, methyl ethyl ether, ethyl ether, ethyl propyl ether, dipropyl ether, dibutyl ether, methyl propyl ether, methyl butyl ether, methyl isobutyl ether, methyl tert-butyl ether, methyl isopentyl ether, methyl tert-amyl ether, methyl cyclopentyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, tetrahydrofuran, tetrahydropyran, and 1,4-dioxane, preferably methyl tert-butyl ether;

[0024] The volume fraction of the ketone in the mixed solution of ketone and alkane is 5%-75%, and the ketone includes one of acetone, butanone, cyclohexanone, methyl isobutyl ketone, and methyl isopropyl ketone, preferably acetone or butanone; the alkane includes one of n-pentane, n-hexane, cyclohexane, n-heptane, n-octane, and isooctane, preferably n-hexane, cyclohexane, and n-heptane.

[0025] Furthermore, in the polymerization reaction system composed of the electron-withdrawing monomer, the olefin monomer, the initiator, and solvent A, the sum of the masses of the electron-withdrawing monomer and the olefin monomer is preferably 0.1-30% of the total mass of the polymerization reaction system, more preferably 5-20%; the mass concentration of the initiator in the polymerization reaction system is preferably 0.04-2.5%; and the temperature of the polymerization reaction is preferably 40-100℃, more preferably 45-80℃.

[0026] Furthermore, after the polymerization reaction is completed, the reaction system is subjected to solid-liquid separation, and the separated copolymer is dried. The solid-liquid separation is carried out by known methods such as filtration, centrifugation, and solvent evaporation. The drying temperature is 40-150℃, preferably 40-100℃.

[0027] Further, the amine compound is one of ammonia, a diamine or polyamine having 2-10 carbon atoms; the molar ratio of the amine compound to the anhydride groups contained in the copolymer is 1-50:1; the imidization reaction is carried out at a temperature of 20-300℃ for 1-24 hours.

[0028] Furthermore, the ammonia gas is added in the form of ammonia water (an aqueous solution of ammonia gas).

[0029] Further, the amine compound is preferably one of ammonia, a diamine or polyamine having 4-10 carbon atoms, more preferably one of ammonia or a diamine having 4-10 carbon atoms; the temperature of the imidization reaction is preferably 20-250°C, more preferably 80-220°C.

[0030] Further, the aldehyde compound is a monoaldehyde with 1-16 carbon atoms; the catalyst A is an inorganic base; the solvent B is one or more of water, 1,4-dioxane, tetrahydrofuran, tetrahydropyran, acetone, butanone, cyclohexanone, methyl isobutyl ketone, methyl isopropyl ketone, N,N-dimethylformamide, and dimethyl sulfoxide; in the hydroxylation reaction system composed of the imidized copolymer, the aldehyde compound, catalyst A, and solvent B, the molar ratio of the aldehyde compound to the hydrogen atoms on the nitrogen atoms of the imidized copolymer is 0.1-10:1, the sum of the mass of the imidized copolymer and the aldehyde compound is 0.1-50% of the total mass of the hydroxylation reaction system, and the mass concentration of catalyst A in the hydroxylation reaction system is 0.00001-10%; the temperature of the hydroxylation reaction is 0-100℃, and the time is 0.01-24h.

[0031] Furthermore, the aldehyde compound is preferably one of formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, n-pentanaldehyde, isovaleraldehyde, and neopentanaldehyde.

[0032] Furthermore, the catalyst A (inorganic base) includes one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate.

[0033] Further, solvent B is preferably one or more of water, 1,4-dioxane, tetrahydrofuran, acetone, N,N-dimethylformamide, and dimethyl sulfoxide.

[0034] Furthermore, in the hydroxylation reaction system composed of the imidized copolymer, aldehyde compound, catalyst A, and solvent B, the molar ratio of the aldehyde compound to the hydrogen atoms on the nitrogen atoms of the imidized copolymer is preferably 0.1-5:1, more preferably 0.5-3:1; the sum of the masses of the imidized copolymer and the aldehyde compound is preferably 5-40% of the total mass of the hydroxylation reaction system; the mass concentration of catalyst A in the hydroxylation reaction system is preferably 0.01-5%; and the temperature of the hydroxylation reaction is preferably 20-100℃, more preferably 30-60℃.

[0035] Furthermore, after the hydroxylation reaction is completed, the reaction system is separated, and the separated hydroxylated copolymer is dried. The separation is carried out by known methods such as filtration, centrifugation, and solvent evaporation. The drying temperature is 40-150℃, preferably 40-100℃.

[0036] Further, the epoxy compound is one of epichlorohydrin, epibromopropane, and α-hydroxypropane (also known as (S)-(-)-1-hydroxy-2,3-epoxypropane or S(-)-glycidyl); the catalyst B is an inorganic base; the catalyst C is a phase transfer catalyst; the non-epoxy solvent C is one or more of water, 1,4-dioxane, tetrahydrofuran, tetrahydropyran, acetone, butanone, cyclohexanone, methyl isobutyl ketone, methyl isopropyl ketone, N,N-dimethylformamide, and dimethyl sulfoxide; and the epoxy solvent D is one or more of epichlorohydrin, epibromopropane, and α-hydroxypropane.

[0037] Furthermore, the epoxy compound is preferably epichlorohydrin or α-hydroxyepoxypropane.

[0038] Furthermore, the catalyst B (inorganic base) includes one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate.

[0039] Furthermore, both catalyst A and catalyst B are inorganic bases, and they may be the same or different.

[0040] Furthermore, the phase transfer catalyst comprises one or more of benzyltriethylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium bisulfate, trioctylmethylammonium chloride, dodecyltrimethylammonium chloride, and tetradecyltrimethylammonium chloride, preferably one or more of benzyltriethylammonium chloride, tetrabutylammonium bromide, and tetrabutylammonium chloride.

[0041] Furthermore, the non-epoxy solvent C is preferably one or more of water, 1,4-dioxane, tetrahydrofuran, tetrahydropyran, acetone, N,N-dimethylformamide, and dimethyl sulfoxide.

[0042] Further, in the epoxidation reaction system of Method 1 or Method 2, the molar ratio of the hydroxyl groups in the epoxy compound and the hydroxylated copolymer is 1-50:1, and the molar ratio of the catalyst B to the epoxy compound is 1-10:1; the sum of the mass of the hydroxylated copolymer and the epoxy compound is 0.1-50% of the total mass of the epoxidation reaction system, and the mass concentration of the catalyst C in the epoxidation reaction system is 0-6%; in the epoxidation reaction system of Method 3 or Method 4, the molar ratio of the hydroxyl groups in the epoxy solvent D and the hydroxylated copolymer is 1-500:1, and the molar ratio of the hydroxyl groups in the catalyst B and the hydroxylated copolymer is 1-15:1; the sum of the mass of the hydroxylated copolymer and the epoxy solvent D is 80-99.9% of the total mass of the epoxidation reaction system, and the mass concentration of the catalyst C in the epoxidation reaction system is 0-5%; the temperature of the epoxidation reaction is 20-160℃, and the time is 0.01-24h.

[0043] Further, the epoxidation reaction system of Method 1 is an epoxidation reaction system composed of the hydroxylated copolymer, epoxy compound, catalyst B, catalyst C, and non-epoxy solvent C; the epoxidation reaction system of Method 2 is an epoxidation reaction system composed of the hydroxylated copolymer, epoxy compound, catalyst B, and non-epoxy solvent C; the epoxidation reaction system of Method 3 is an epoxidation reaction system composed of the hydroxylated copolymer catalyst B, catalyst C, and epoxy solvent D; and the epoxidation reaction system of Method 4 is an epoxidation reaction system composed of the hydroxylated copolymer catalyst B and epoxy solvent D.

[0044] Furthermore, in the epoxidation reaction system of Method 1 or Method 2, the molar ratio of the hydroxyl group in the epoxy compound and the hydroxylated copolymer is preferably 1-40:1, more preferably 1-25:1; the sum of the mass of the hydroxylated copolymer and the epoxy compound is preferably 0.1-40% of the total mass of the epoxidation reaction system, more preferably 5-30%.

[0045] Furthermore, the temperature of the epoxidation reaction is preferably 40-160℃, more preferably 90-160℃; the reaction time is preferably 1-12h.

[0046] Furthermore, after the epoxidation reaction is completed, the reaction system is separated, and the separated hydroxylated copolymer is dried. The separation is carried out by known methods such as filtration, centrifugation, and solvent evaporation. The drying temperature is 40-150℃, preferably 40-100℃.

[0047] The third technical solution of the present invention: a method for modifying epoxy resin using the above-mentioned toughening agent, comprising the following steps: dissolving epoxy resin and the above-mentioned toughening agent in solvent E, heating and adding curing agent, and after the curing agent is dissolved, pouring it into a mold, then pre-curing and then curing to obtain the modified epoxy resin composite material.

[0048] Further, the mass ratio of the epoxy resin to the toughening agent is 10:0.25-1; the curing agent is diaminodiphenylmethane; and the solvent E is one of methanol, ethanol, acetone, butanone, and tetrahydrofuran.

[0049] Furthermore, the mass ratio of the epoxy resin to the curing agent is 10:2.5.

[0050] Furthermore, the heating is performed to 80°C.

[0051] Furthermore, the pre-curing temperature is 70-100℃, preferably 80℃, and the time is 1-4h, preferably 2h; the curing temperature is 120-180℃, preferably 150℃, and the time is 1-4h, preferably 4h.

[0052] Furthermore, after dissolving the epoxy resin and toughening agent in solvent E, the method further includes the step of adding additives.

[0053] Furthermore, the additives include fillers.

[0054] The present invention discloses the following technical effects:

[0055] The toughening agent of this invention contains epoxy groups in its molecular structure, which contributes to good compatibility between the toughening agent molecule and epoxy resin. Furthermore, the toughening agent molecule of this invention simultaneously possesses flexible and rigid segments, thus achieving a balance between toughness and rigidity. Additionally, the toughening agent molecule also contains an imide ring, which provides certain hydrophobicity and heat resistance. In summary, the epoxy resin toughening agent of this invention exhibits excellent compatibility with the epoxy resin matrix. When used to modify epoxy resin materials, it imparts good toughness to the epoxy resin composite material while largely preserving the original rigidity and heat resistance of the epoxy resin composite material. Attached Figure Description

[0056] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0057] Figure 1The infrared spectra of the copolymer (#1) obtained in step (a) of Example 1, the imidized copolymer (#2) obtained in step (b) of Example 1, the hydroxylated copolymer (#3) obtained in step (c) of Example 1, and the epoxidized copolymer (#4) obtained in step (d) of Example 1 are shown.

[0058] Figure 2 The 1H NMR spectrum of the epoxidized copolymer obtained in step (d) of Example 1 of the present invention. Detailed Implementation

[0059] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0060] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0061] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0062] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be obvious to those skilled in the art. This application specification and embodiments are merely exemplary.

[0063] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0064] Example 1

[0065] An epoxy resin toughening agent is prepared by the following steps:

[0066] (a) Preparation of copolymers

[0067] Put 1g (0.004mol) of octadecene ( ) and 1g (0.01mol) maleic anhydride ( The copolymer was dissolved and dispersed in 37g of methyl tert-butyl ether, and 1g of azobisisobutyronitrile was added. After stirring to dissolve, nitrogen gas was purged for 10min to remove oxygen. The mixture was then placed in an oil bath at 80℃ for polymerization for 6h. After the reaction, a solid-liquid dispersion of the copolymer was obtained. After separation, washing, and drying (at 45℃), the copolymer was obtained. (n=25).

[0068] (b) Preparation of imidized copolymers

[0069] Under sealed conditions, 8g of ammonia water (concentration 25%, density 0.91g / cm³) was added to 1g of copolymer (containing 0.0029mol of acid anhydride). 3 The imidization reaction was carried out at 80℃ for 12 hours. After the reaction, the copolymer was separated, washed, and dried (at 100℃) to obtain the imidized copolymer. (n=25).

[0070] (c) Preparation of hydroxylated copolymers

[0071] 1 g of imidized copolymer (0.0029 mol of hydrogen atoms on nitrogen atom) was dissolved in 38 g of acetone, and 0.5 g (0.0058 mol) of neopentaldehyde was added to it. ) and 0.5g sodium hydroxide were stirred to dissolve them, and then hydroxylation was carried out at room temperature (25℃) for 24 hours. After the reaction was completed, methyl tert-butyl ether was added to precipitate the product. After separation, washing, and drying (drying temperature 60℃), the hydroxylated copolymer was obtained. (n=25).

[0072] (d) Preparation of epoxidized copolymers

[0073] 1 g of hydroxylated copolymer (containing 0.0023 mol of hydroxyl groups) was dissolved in 40 g of 1,4-dioxane, and then 5 g (0.054 mol) of epichlorohydrin was added to it. After stirring to dissolve the epoxidized material, 4g (0.125mol) of sodium hydroxide was added, and an epoxidation reaction was carried out at 160℃ for 12 hours. After the reaction was completed, the mixture was filtered, precipitated, washed, and dried (at 90℃) to obtain the epoxidized copolymer (denoted as epoxidized olefin-maleimide copolymer-1, with the structural formula as follows). (a+b=n=25, a=16, b=9), epoxy value is 13mol / 100g (obtained by titration according to national standard GB / T 1677-2008), which is the final toughening agent.

[0074] The infrared spectra of the copolymer (#1) obtained in step (a), the imidized copolymer (#2) obtained in step (b), the hydroxylated copolymer (#3) obtained in step (c), and the epoxidized copolymer (#4) obtained in step (d) of this embodiment are as follows: Figure 1 As shown; the 1H NMR spectrum of the epoxidized copolymer obtained in step (d) is as follows. Figure 2 As shown. Figure 1 Middle #1 to #2: #1 Middle 1800 and 1860cm -1 The characteristic peaks of the anhydride groups on the left and right disappear, and the peaks at 1720 and 1780 cm⁻¹ disappear. -1 The presence of characteristic peaks of five-membered ring imides on both sides indicates the completion of the imide reaction; the peak at 1060 cm⁻¹ in #2 to #3... -1 The presence of stretching vibration characteristic peaks of CO on both sides indicates that the hydroxyl group has successfully reacted. Figure 2 In the diagram, a is the characteristic peak of H on -OH, c is the characteristic peak of hydrogen on C adjacent to -OH, b is the characteristic peak of hydrogen on C in NCO, and df is the characteristic peak of hydrogen on carbon atom of epoxy group. Figure 1 and Figure 2 Together, they demonstrate that the final epoxidized copolymer was obtained.

[0075] Example 2

[0076] An epoxy resin toughening agent is prepared by the following steps:

[0077] (a) Preparation of copolymers

[0078] Put 1g (0.006mol) of dodecene ( ) and 1g (0.009mol) itaconic anhydride ( The copolymer was dissolved and dispersed in 9.5g of ethyl acetate, and 0.5g of azobisisobutyronitrile was added. After stirring to dissolve, nitrogen gas was purged for 10min to remove oxygen. The mixture was then placed in an oil bath at 80℃ for polymerization for 2h. After the reaction, a solid-liquid dispersion of the copolymer was obtained. After separation, washing, and drying (at 70℃), the copolymer was obtained. (n=30).

[0079] (b) Preparation of imidized copolymers

[0080] Under sealed conditions, 1 g (0.009 mol) of hexamethylenediamine was added to 1 g of copolymer (containing 0.0036 mol of acid anhydride). The imidization reaction was carried out at 50℃ for 24 hours. After the reaction, the copolymer was separated, washed, and dried (at 40℃) to obtain the imidized copolymer. (n=30).

[0081] (c) Preparation of hydroxylated copolymers

[0082] 1 g of imidized copolymer (0.0053 mol of hydrogen atoms on nitrogen atoms) was dissolved in 8.2 g of water, and 0.3 g (0.01 mol) of paraformaldehyde (HCHO) was added to it. x (x=8) and 0.5g potassium hydroxide were stirred to dissolve them, and then a hydroxylation reaction was carried out at 60℃ for 2 hours. After the reaction was completed, methyl tert-butyl ether was added to precipitate the product. After separation, washing, and drying, the hydroxylated copolymer ( (n=30).

[0083] (d) Preparation of epoxidized copolymers

[0084] 1 g of hydroxylated copolymer (containing 0.0045 mol of hydroxyl groups) was dissolved in 30.9 g of N,N-dimethylformamide, and then 1 g (0.014 mol) of α-hydroxypropylene oxide was added to it. After stirring to dissolve the epoxidized material, 5g (0.125mol) of sodium hydroxide and 2.1g of benzyltriethylammonium chloride were added. An epoxidation reaction was carried out at 90℃ for 0.2h. After the reaction, the mixture was filtered, precipitated, washed, and dried (at 80℃) to obtain the epoxidized copolymer (denoted as epoxidized olefin-itaconimide copolymer-1, structural formula: [structural formula would be inserted here]). (a+b+c+d+e+f=n=30), with an epoxy value of 10mol / 100g, which is the final toughening agent.

[0085] Example 3

[0086] (a) Preparation of copolymers

[0087] Put 1g (0.012mol) of cyclohexene ( 1 g (0.01 mol) of maleic anhydride was dissolved and dispersed in a mixed solution of 37 g of butanone and n-heptane, wherein the volume ratio of butanone to n-heptane was 3:2. 1 g of benzoyl peroxide was added, and the mixture was stirred until dissolved. Nitrogen gas was purged for 10 min to remove oxygen, and the mixture was placed in a 60°C oil bath for polymerization for 10 h. After the reaction, a solid-liquid dispersion of the copolymer was obtained. After separation, washing, and drying (at 50°C), the copolymer (…) was obtained. (n=10).

[0088] (b) Preparation of imidized copolymers

[0089] Under sealed conditions, 0.5 g (0.003 mol) of decanediamine was added to 1 g of copolymer (containing 0.0056 mol of acid anhydride). The imidization reaction was carried out at 200℃ for 1 hour. After the reaction, the copolymer was separated, washed, and dried (at 100℃) to obtain the imidized copolymer. (n=10).

[0090] (c) Preparation of hydroxylated copolymers

[0091] 1 g of imidized copolymer (0.0028 mol of hydrogen atoms on nitrogen atom) was dissolved in 17 g of dimethyl sulfoxide, and 1 g (0.0139 mol) of isobutyraldehyde was added to it. ) and 1g of sodium bicarbonate were stirred to dissolve, and then hydroxylation was carried out at 30℃ for 10h. After the reaction was completed, methyl tert-butyl ether was added to precipitate the product. After separation, washing, and drying (drying temperature 40℃), the hydroxylated copolymer was obtained. (n=10).

[0092] (d) Preparation of epoxidized copolymers

[0093] 1 g of hydroxylated copolymer (containing 0.0024 mol of hydroxyl groups) was dissolved in 30.9 g of N,N-dimethylformamide. Then, 1 g (0.013 mol) of α-hydroxypropylene oxide was added, and the mixture was stirred until dissolved. Next, 5 g (0.089 mol) of potassium hydroxide and 2.1 g of tetrabutylammonium bromide were added, and an epoxidation reaction was carried out at 150 °C for 1 h. After the reaction, the mixture was filtered, precipitated, washed, and dried (at 100 °C) to obtain the epoxidized copolymer (denoted as epoxidized cycloolefin-maleimide copolymer-1, with the structural formula...). (a+b+c+d=n=10), with an epoxy value of 15mol / 100g, which is the final toughening agent.

[0094] Example 4

[0095] An epoxy resin toughening agent is prepared by the following steps:

[0096] (a) Preparation of copolymers

[0097] Put 1g (0.0096mol) of styrene ( 1 g (0.009 mol) of itaconic anhydride was dissolved and dispersed in 37 g of isoamyl acetate. 1 g of azobisisobutyronitrile was added, and the mixture was stirred until dissolved. Nitrogen gas was purged for 10 min to remove oxygen, and the mixture was placed in a 70°C oil bath for polymerization for 6 h. After the reaction, a solid-liquid dispersion of the copolymer was obtained. After separation, washing, and drying (at 70°C), the copolymer (…) was obtained. (n=100).

[0098] (b) Preparation of imidized copolymers

[0099] Under sealed conditions, 10g (0.11mol) of butanediamine was added to 1g of copolymer (containing 0.0046mol of acid anhydride). The imidization reaction was carried out at 150℃ for 5 hours. After the reaction, the copolymer was separated, washed, and dried (at 100℃) to obtain the imidized copolymer. (n=100).

[0100] (c) Preparation of hydroxylated copolymers

[0101] 1 g of imidized copolymer (0.0033 mol of hydrogen atoms on nitrogen atom) was dissolved in 40 g of 1,4-dioxane, and 1 g (0.0227 mol) of acetaldehyde was added to it. ) and 2.1g of potassium carbonate were stirred to dissolve, and then hydroxylation was carried out at 40℃ for 1 hour. After the reaction was completed, methyl tert-butyl ether was added to precipitate the product. After separation, washing, and drying (at 40℃), the hydroxylated copolymer was obtained. (n=100).

[0102] (d) Preparation of epoxidized copolymers

[0103] 1 g of hydroxylated copolymer (containing 0.0026 mol of hydroxyl groups) was dissolved in 40 g (0.54 mol) of α-hydroxy propylene oxide. After stirring until dissolved, 5 g (0.036 mol) of potassium carbonate was added, and an epoxidation reaction was carried out at 160 °C for 5 h. After the reaction, the copolymer was filtered, precipitated, washed, and dried (drying temperature was 100 °C) to obtain the epoxidized copolymer (denoted as epoxidized olefin-itaconimide copolymer-2, structural formula is (...) (a+b+c=n=100), with an epoxy value of 20mol / 100g, which is the final toughening agent.

[0104] Example 5

[0105] An epoxy resin toughening agent is prepared by the following steps:

[0106] (a) Preparation of copolymers

[0107] 2 g (0.013 mol) of catalytic hydrogenation raffinate (composition shown in Table 1) and 2 g (0.018 mol) of itaconic anhydride were dissolved and dispersed in 40 g of xylene. 1.68 g of azobisisobutyronitrile was added, and the mixture was stirred until dissolved. Nitrogen gas was purged for 10 min to remove oxygen, and the mixture was placed in an 80°C oil bath for polymerization for 2 h. After the reaction, a solid-liquid dispersion of the copolymer was obtained. After separation, washing, and drying (at 45°C), the copolymer (…) was obtained. A represents structural unit I, specifically alkanes with 4 carbon atoms, alkanes with 5 carbon atoms, alkanes with 6 carbon atoms, alkanes with 7 carbon atoms, and alkanes with 8 carbon atoms; B represents structural unit II, specifically cycloalkanes with 5 carbon atoms, cycloalkanes with 6 carbon atoms, cycloalkanes with 7 carbon atoms, and cycloalkanes with 8 carbon atoms; a+b=23).

[0108] Table 1

[0109]

[0110] C represents the number of carbon atoms; nP represents n-alkanes; iP represents isoalkanes; O represents alkenes; N represents cycloalkenes; A represents aromatics; Sum and Total represent mass fractions, and all units in the above tables are %.

[0111] (b) Preparation of imidized copolymers

[0112] Under sealed conditions, 1g (0.009mol) of p-phenylenediamine was added to 1g of a copolymer (containing 0.0056mol of acid anhydride, obtained by titration: the copolymer was dissolved in acetone, then excess 10% sodium hydroxide solution was added, and after standing for 30 minutes, it was titrated with 1mol / L hydrochloric acid standard solution and a potentiometric titrator). The imidization reaction was carried out at 140℃ for 2 hours. After the reaction, the copolymer was separated, washed, and dried (at 80℃) to obtain the imidized copolymer. (a+b=23).

[0113] (c) Preparation of hydroxylated copolymers

[0114] 1 g of imidized copolymer (0.01 mol of hydrogen atoms on nitrogen atom) was dissolved in 40 g of tetrahydrofuran, and 1 g (0.0116 mol) of n-pentanal was added to it. ) and 2.1g of sodium carbonate were stirred to dissolve, and then hydroxylation was carried out at 60℃ for 24 hours. After the reaction was completed, methyl tert-butyl ether was added to precipitate the product. After separation, washing, and drying (drying temperature 40℃), the hydroxylated copolymer was obtained. (a+b=23).

[0115] (d) Preparation of epoxidized copolymers

[0116] 1 g of the hydroxylated copolymer (containing 0.008 mol of hydroxyl groups) was dissolved in 40 g (0.43 mol) of epichlorohydrin. After stirring until dissolved, 5 g (0.047 mol) of sodium carbonate and 2.1 g of benzyltriethylammonium chloride were added. An epoxidation reaction was carried out at 160 °C for 0.1 h. After the reaction, the copolymer was filtered, precipitated, washed, and dried (at 70 °C) to obtain the epoxidized copolymer (denoted as epoxidized cycloolefin-itaconimide copolymer-1, structural formula: [structural formula would be inserted here]). (a+b+c+d+e+f=23), with an epoxy value of 13mol / 100g, which is the final toughening agent.

[0117] Application Example 1

[0118] The preparation of an epoxy resin composite material (toughening modification of epoxy resin) involves the following steps:

[0119] 10g of E51 and 0.25g of epoxidized olefin-maleimide copolymer-1 (the final product obtained in step (d) of Example 1) were dissolved in acetone, heated to 80°C, and then 2.5g of DDM (diaminodiphenylmethane) was added. After the DDM dissolved, the mixture was poured into a mold, pre-cured at 80°C for 2 hours, and then cured at 150°C for 4 hours to obtain the epoxy resin composite material.

[0120] Application Example 2

[0121] The preparation of an epoxy resin composite material (toughening modification of epoxy resin) involves the following steps:

[0122] 10g of E51 and 0.5g of epoxidized olefin-maleimide copolymer-1 (the final product obtained in step (d) of Example 1) were dissolved in acetone, heated to 80°C, and then 2.5g of DDM was added. After the DDM dissolved, the mixture was poured into a mold, pre-cured at 80°C for 2 hours, and then cured at 150°C for 4 hours to obtain the epoxy resin composite material.

[0123] Application Example 3

[0124] The preparation of an epoxy resin composite material (toughening modification of epoxy resin) involves the following steps:

[0125] 10g of E51 and 0.75g of epoxidized olefin-maleimide copolymer-1 (the final product obtained in step (d) of Example 1) were dissolved in acetone, heated to 80°C, and then 2.5g of DDM was added. After the DDM dissolved, the mixture was poured into a mold, pre-cured at 80°C for 2 hours, and then cured at 150°C for 4 hours to obtain the epoxy resin composite material.

[0126] Application Example 4

[0127] The preparation of an epoxy resin composite material (toughening modification of epoxy resin) involves the following steps:

[0128] 10g of E51 and 1g of epoxidized olefin-maleimide copolymer-1 (the final product obtained in step (d) of Example 1) were dissolved in acetone, heated to 80°C, and then 2.5g of DDM was added. After the DDM dissolved, the mixture was poured into a mold, pre-cured at 80°C for 2 hours, and then cured at 150°C for 4 hours to obtain the epoxy resin composite material.

[0129] Application Example 5

[0130] Same as Application Example 1, except that an equal mass of epoxide-olefin-itaconimid copolymer-1 (the final product obtained in step (d) of Example 2) is used instead of epoxide-olefin-maleimide copolymer-1 (the final product obtained in step (d) of Example 1).

[0131] Application Example 6

[0132] Same as Application Example 1, except that an equal mass of epoxidized cyclic olefin-maleimide copolymer-1 (the final product obtained in step (d) of Example 3) is used instead of epoxidized olefin-maleimide copolymer-1 (the final product obtained in step (d) of Example 1).

[0133] Application Example 7

[0134] Same as Application Example 1, except that an equal mass of epoxide-olefin-itaconimid copolymer-2 (the final product obtained in step (d) of Example 4) is used instead of epoxide-olefin-maleimide copolymer-1 (the final product obtained in step (d) of Example 1).

[0135] Application Example 8

[0136] Same as Application Example 1, except that an equal mass of epoxidized cyclic olefin-itaconimid copolymer-1 (the final product obtained in step (d) of Example 5) is used instead of epoxidized olefin-maleimide copolymer-1 (the final product obtained in step (d) of Example 1).

[0137] Example 1

[0138] The epoxy resin composites prepared in Application Examples 1-8 were subjected to performance tests (with E51 as a blank control). The test items included impact strength, tensile strength, and heat resistance index (T). s ) and contact angle.

[0139] Impact strength was determined according to GB / T 1043.2-2008 "Determination of Impact Properties of Simply Supported Beams in Plastics", with sample dimensions of 80×10×4mm. 3 Tensile strength was determined according to GB / T 1040.2-2022 "Determination of Tensile Properties of Plastics", with sample type 5A selected; heat resistance index (T s According to the formula Calculate, where T 5% The temperature at which the sample decomposes by 5%; T 30% The temperature at which the sample decomposes by 30% is represented by T. 5% and T 30% The contact angle was determined by thermogravimetric analysis; the contact angle was measured according to GB / T 30693-2014 "Measurement of the contact angle between plastic film and water".

[0140] The test results are shown in Table 1:

[0141] Table 1

[0142]

[0143] Table 1 shows that impact strength is used to characterize the toughness of the composite material. After adding the toughening agents prepared in Examples 1-5 of this invention, the toughness of E51 is significantly improved. Tensile strength is used to characterize the rigidity of the composite material. After adding the epoxidized olefin-maleimide copolymer, the rigidity of E51 is also significantly improved. Statistical heat resistance index (T...) s The heat resistance of E51 was evaluated using the epoxide-olefin-maleimide copolymer. The addition of the epoxide-olefin-maleimide copolymer did not significantly reduce its heat resistance. The contact angle was used to characterize the hydrophobicity of the composite material. The addition of the epoxide-olefin-maleimide copolymer also greatly improved the hydrophobicity of E51.

[0144] Application Example 9

[0145] 10g of E44 and 0.25g of epoxidized olefin-maleimide copolymer-1 (the final product obtained in step (d) of Example 1) were mixed and heated to 150°C. Then 5g of DDM was added. After the DDM dissolved, the mixture was poured into a mold and pre-cured at 80°C for 2 hours, and then cured at 150°C for 4 hours to obtain the epoxy resin composite material.

[0146] Application Example 10

[0147] 10g of E44 and 0.5g of epoxidized olefin-maleimide copolymer-1 (the final product obtained in step (d) of Example 1) were mixed and heated to 150°C. Then 5g of DDM was added. After the DDM dissolved, the mixture was poured into a mold and pre-cured at 80°C for 2 hours, and then cured at 150°C for 4 hours to obtain the epoxy resin composite material.

[0148] Application Example 11

[0149] 10g of E44 and 0.75g of epoxidized olefin-maleimide copolymer-1 (the final product obtained in step (d) of Example 1) were mixed and heated to 150°C. Then 5g of DDM was added. After the DDM dissolved, the mixture was poured into a mold and pre-cured at 80°C for 2 hours, and then cured at 150°C for 4 hours to obtain the epoxy resin composite material.

[0150] Application Example 12

[0151] 10g of E44 and 1g of epoxidized olefin-maleimide copolymer-1 (the final product obtained in step (d) of Example 1) were mixed and heated to 150°C. Then 5g of DDM was added. After the DDM was dissolved, the mixture was poured into a mold and pre-cured at 80°C for 2 hours, and then cured at 150°C for 4 hours to obtain the epoxy resin composite material.

[0152] Application Example 13

[0153] Same as Application Example 1, except that an equal mass of epoxide-olefin-itaconimid copolymer-1 (the final product obtained in step (d) of Example 2) is used instead of epoxide-olefin-maleimide copolymer-1 (the final product obtained in step (d) of Example 1).

[0154] Application Example 14

[0155] Same as Application Example 1, except that an equal mass of epoxidized cyclic olefin-maleimide copolymer-1 (the final product obtained in step (d) of Example 3) is used instead of epoxidized olefin-maleimide copolymer-1 (the final product obtained in step (d) of Example 1).

[0156] Application Example 15

[0157] Same as Application Example 1, except that an equal mass of epoxide-olefin-itaconimid copolymer-2 (the final product obtained in step (d) of Example 4) is used instead of epoxide-olefin-maleimide copolymer-1 (the final product obtained in step (d) of Example 1).

[0158] Application Example 16

[0159] Same as Application Example 1, except that an equal mass of epoxidized cyclic olefin-itaconimid copolymer-1 (the final product obtained in step (d) of Example 5) is used instead of epoxidized olefin-maleimide copolymer-1 (the final product obtained in step (d) of Example 1).

[0160] Example 2

[0161] The epoxy resin composites prepared in Application Examples 9-16 were subjected to performance tests (with E44 as a blank control). The test items included impact strength, tensile strength, heat resistance index (Ts) and contact angle.

[0162] The test results are shown in Table 2:

[0163] Table 2

[0164]

[0165] As shown in Table 2, after adding the toughening agent prepared in Examples 1-5 of this invention, the impact performance, tensile strength and hydrophobicity of epoxy resin E44 are greatly improved while maintaining the heat resistance of epoxy resin E44.

[0166] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A toughening agent for epoxy resin, characterized in that, The toughening agent is a copolymer containing epoxy groups, wherein the copolymer includes one or more of structural units I-II, and one or more of structural units III, VI, VII, VIII, XII, XV, XVI, and XVII. 、 、 、 、 、 、 、 、 、 ； Among them, R 1-4 R5 is selected independently from one of the following: hydrogen atom, alkyl group having 1-16 carbon atoms, and aryl group having 6-16 carbon atoms; R6 and R7 are selected independently from one of the following: hydrogen atom or methyl group; R8 is selected from one of the following: hydrogen atom, alkyl group having 1-17 carbon atoms; R9 is selected from one of the following: alkyl group having 2-10 carbon atoms, and aryl group having 6-13 carbon atoms.

2. A method for preparing an epoxy resin toughening agent as described in claim 1, characterized in that, Includes the following steps: Electron-withdrawing monomers, olefin monomers, and initiators are dissolved in solvent A and polymerized to obtain a copolymer. The copolymer is then mixed with an amine compound and imidized to obtain an imidized copolymer. The imidized copolymer is then mixed with an aldehyde compound, catalyst A, and solvent B and hydroxylated to obtain a hydroxylated copolymer. The hydroxylated copolymer is then epoxidized using one of the following four methods to obtain an epoxidized copolymer, which is the toughening agent for epoxy resin. Method 1: The hydroxylated copolymer is mixed with an epoxy compound, catalyst B, catalyst C, and a non-epoxy solvent C to carry out an epoxidation reaction; Method 2: The hydroxylated copolymer is mixed with an epoxy compound, catalyst B, and a non-epoxy solvent C to carry out an epoxidation reaction; Method 3: The hydroxylated copolymer is mixed with catalyst B, catalyst C and epoxy solvent D to carry out an epoxidation reaction; Method 4: Mix the hydroxylated copolymer with catalyst B and epoxy solvent D to carry out an epoxidation reaction.

3. The preparation method according to claim 2, characterized in that, The electron-withdrawing monomer is one of maleic anhydride, itaconic anhydride, and their derivatives; the olefin monomer is one or more of chain olefins, cyclic olefins, aromatic olefins, conjugated dienes, and their derivatives having 2-18 carbon atoms; the initiator is one or more of peroxide initiators and azo initiators; the solvent A is one of organic acid alkyl esters, aromatic solvents, ether solvents, ketones, and alkanes; in the polymerization reaction system composed of the electron-withdrawing monomer, olefin monomer, initiator, and solvent A, the molar ratio of the electron-withdrawing monomer to the olefin monomer is 0.1-3:1, the sum of the mass of the electron-withdrawing monomer and the olefin monomer is 0.1-50% of the total mass of the polymerization reaction system, and the mass concentration of the initiator in the polymerization reaction system is 0.0001-5%; the polymerization reaction temperature is 40-120℃, and the time is 1-12h.

4. The preparation method according to claim 2, characterized in that, The amine compound is one of ammonia, a diamine or polyamine having 2-10 carbon atoms; the molar ratio of the amine compound to the anhydride groups contained in the copolymer is 1-50:1; the imidization reaction is carried out at a temperature of 20-300℃ for 1-24 hours.

5. The preparation method according to claim 2, characterized in that, The aldehyde compound is a monoaldehyde with 1-16 carbon atoms; the catalyst A is an inorganic base; the solvent B is one or more of water, 1,4-dioxane, tetrahydrofuran, tetrahydropyran, acetone, butanone, cyclohexanone, methyl isobutyl ketone, methyl isopropyl ketone, N,N-dimethylformamide, and dimethyl sulfoxide; in the hydroxylation reaction system composed of the imidized copolymer, the aldehyde compound, catalyst A, and solvent B, the molar ratio of the aldehyde compound to the hydrogen atoms on the nitrogen atoms of the imidized copolymer is 0.1-10:1, the sum of the mass of the imidized copolymer and the aldehyde compound is 0.1-50% of the total mass of the hydroxylation reaction system, and the mass concentration of catalyst A in the hydroxylation reaction system is 0.00001-10%; the temperature of the hydroxylation reaction is 0-100℃, and the time is 0.01-24h.

6. The preparation method according to claim 2, characterized in that, The epoxy compound is one of epichlorohydrin, epibromopropane, and α-hydroxypropane; the catalyst B is an inorganic base; the catalyst C is a phase transfer catalyst; the non-epoxy solvent C is one or more of water, 1,4-dioxane, tetrahydrofuran, tetrahydropyran, acetone, butanone, cyclohexanone, methyl isobutyl ketone, methyl isopropyl ketone, N,N-dimethylformamide, and dimethyl sulfoxide; the epoxy solvent D is one or more of epichlorohydrin, epibromopropane, and α-hydroxypropane.

7. The preparation method according to claim 2, characterized in that, In the epoxidation reaction system of Method 1 or Method 2, the molar ratio of the hydroxyl groups in the epoxy compound and the hydroxylated copolymer is 1-50:1, and the molar ratio of the catalyst B to the epoxy compound is 1-10:1; the sum of the mass of the hydroxylated copolymer and the epoxy compound is 0.1-50% of the total mass of the epoxidation reaction system, and the mass concentration of the catalyst C in the epoxidation reaction system is 0-6%; in the epoxidation reaction system of Method 3 or Method 4, the molar ratio of the hydroxyl groups in the epoxy solvent D and the hydroxylated copolymer is 1-500:1, and the molar ratio of the hydroxyl groups in the catalyst B and the hydroxylated copolymer is 1-15:1; the sum of the mass of the hydroxylated copolymer and the epoxy solvent D is 80-99.9% of the total mass of the epoxidation reaction system, and the mass concentration of the catalyst C in the epoxidation reaction system is 0-5%; the temperature of the epoxidation reaction is 20-160℃, and the time is 0.01-24h.

8. A method for modifying epoxy resin using the toughening agent according to claim 1, characterized in that, Includes the following steps: The epoxy resin and the toughening agent described in claim 1 are dissolved in solvent E, heated, and then a curing agent is added. After the curing agent is dissolved, the mixture is poured into a mold, pre-cured, and then cured to obtain the modified epoxy resin composite material.

9. The method as described in claim 8, characterized in that, The mass ratio of epoxy resin to toughening agent is 10:0.25-1; the curing agent is diaminodiphenylmethane; the solvent E is one of methanol, ethanol, acetone, butanone, and tetrahydrofuran; the pre-curing temperature is 70-100℃ and the time is 1-4h; the curing temperature is 120-180℃ and the time is 1-4h.

10. The method as described in claim 8, characterized in that, The step of dissolving epoxy resin and toughening agent in solvent E further includes adding additives.

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