WO2021174803A1

WO2021174803A1 - Epoxy resin cured product, composite material, and preparation methods

Info

Publication number: WO2021174803A1
Application number: PCT/CN2020/115084
Authority: WO
Inventors: 严兵; 赵清新; 郎鸣华; 何定军; 刘成; 于洋; 张林强; 刘圣强; 刘腾达; 郭海军
Original assignee: 江苏澳盛复合材料科技有限公司
Priority date: 2020-03-06
Filing date: 2020-09-14
Publication date: 2021-09-10
Also published as: CN111286006B; CN111286006A

Abstract

The present invention relates to an epoxy resin cured product, a composite material, and preparation methods. The epoxy resin cured product is prepared from raw materials comprising epoxy resin and a curing agent. Epoxy resin has a chemical structure represented by formula (I). X comprises at least one of X1 and X2: X1 has a chemical structure represented by the formula, and X2 has a chemical structure represented by the formula. The adhesive force between the epoxy resin cured product of the present invention and a reinforcing material is strong, the density of the prepared composite material is reduced while the mechanical strength is high, and the present invention is suitable for blades of a wind driven generator and is beneficial to improving the power generation capacity of the wind driven generator.

Description

Cured epoxy resin, composite material and preparation method thereof

Technical field

The invention relates to the field of materials, in particular to a cured epoxy resin, a composite material and a preparation method thereof.

Background technique

Among the utilization forms of wind energy, wind power technology is the most mature and has the most commercial development prospects. As a clean energy, wind power is of great significance to solving energy shortage and environmental protection problems, so it is getting more and more attention from countries all over the world. Large-scale use of wind power is also one of the effective measures to reduce harmful gas emissions. Today, when power shortages and energy shortages follow one after another, wind power generation has become a trend.

A wind turbine is a power device that converts wind energy into mechanical work, which drives the rotor to rotate, and finally outputs alternating current. Wind turbines generally consist of wind turbines, generator direction regulators (tail fins), towers, speed-limiting safety mechanisms, and energy storage devices. According to the current windmill technology, electricity can be generated at a breeze speed of three meters per second.

There are many ways to increase the power generation of wind turbines, such as installing variable frequency devices to output constant frequency AC power, and output constant frequency AC power, which can provide more power. Install an intelligent control system that adjusts the blades in real time to control the direction of the blade facing the wind. When the rotor of the wind turbine is facing the wind direction, the wind turbine can get the most wind energy and the more electricity it can get. Use lubricating oil appropriately. The use of lubricating oil, especially for the main gearbox, can reduce the loss of the fan as much as possible, thereby increasing the power generation.

While maintaining the mechanical strength of the blades, reducing the weight of the blades is also an effective way to increase the power generation of wind turbines. The blade is the most basic and critical component in a wind turbine. The harsh environment and long-term non-stop operation require the blades to have high mechanical strength. At the same time, reducing the weight of the blades can speed up the rotation of the blades and increase the conversion rate of wind energy into electrical energy, thereby increasing the power generation of wind turbines.

The blade is a composite material composed of matrix resin/reinforced material. The matrix resin includes cured epoxy resin, cured vinyl resin, cured unsaturated resin, etc., which provide the basic mechanical properties and durability of the blade. The blades made of pure resin are insufficient in strength, rigidity, and durability, so they need to be composited with reinforcing materials such as glass fiber and carbon fiber.

There are the following methods to reduce the weight of the blade while maintaining the mechanical strength of the blade. For example, carbon fiber is used to replace glass fiber in whole or in part, the density of matrix resin is reduced through modification, and porous material is added.

Chinese patent CN108690330A is a special lightweight composite material for wind power generation equipment: It is prepared by using modified glass beads and modified chopped hollow carbon fibers as reinforcing materials, and by adjusting the density, particle size and content of the glass beads in the matrix Lightweight composite materials for blades, but the dispersibility of glass beads in the matrix resin and interfacial bonding still have certain problems, which affect the mechanical properties of composite materials.

Chinese patent CN101418070A epoxy resin composition, composite material and preparation method thereof: an epoxy resin composition composed of epoxy resin, a small molecule compound with one or more epoxy groups and an amine curing agent is used as the matrix resin , Through the liquid molding process and the reinforcement material compound, the high-performance epoxy resin-based composite material is prepared. Although a high-performance composite material was prepared by blending and modifying common epoxy resins, the density of the composite material was not improved, and it could not meet the requirements of lightweight blades.

For this reason, there is still a need for a cured epoxy resin and its composite material with low density, high mechanical strength, and durability.

Summary of the invention

An object of the present invention is to provide a low density and high strength cured epoxy resin, the density may be 1.10g / cm ³ or less, even at 1.00g / cm ³ or less, the drawing strength of greater than 2650MPa, the impact strength of greater than 20KJ / m ² .

In order to achieve the above objective, the technical solution adopted by the present invention is:

A cured epoxy resin prepared from raw materials containing epoxy resin and curing agent, wherein:

Epoxy resin: The epoxy resin has the following chemical structure:

Where: X contains at least one of X1 and X2:

X1 has the following chemical structure:

X2 has the following chemical structure: -R-O formula 3,

Wherein: R in X2 is a group with no less than 4 carbon atoms and only containing carbon and hydrogen.

X1 is a bisphenol A epoxy resin with the above chemical structure. Bisphenol A epoxy resin is a general epoxy resin. It has the characteristics of good adhesion to carbon fiber, good overall performance, and easy availability of raw materials. The density of phenol A epoxy resin is relatively high, which cannot meet the characteristics of light weight of the required composite material.

X2 is a long-chain hydrocarbon group with the above chemical structure, which can reduce the density of the epoxy resin. The structure forming the X2 structure substance must contain two alcoholic hydroxyl groups, and the number of carbon atoms should not be less than 4. Examples, but not limited to, the following comonomers can form the X2 structure: butanediol, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, undecanediol , Tetradecanediol. The more the number of carbon atoms in R, the lower the density of the epoxy resin, but when the number of carbon atoms in R is greater than 10, its mechanical properties and durability will be reduced. Preferably, R is an alkyl group having 4 to 10 carbon atoms, and more preferably, R is an alkyl group having 4 to 6 carbon atoms.

Preferably, R in X2 contains the following chemical structure:

Formula 4 can improve the adhesion between the cured epoxy resin and the reinforcing material. Among them: R1 is an alkyl group, and the structure of the X2 structure containing formula 4 needs to contain two alcoholic hydroxyl groups at the 1st and 2nd positions, and the number of carbon atoms is not less than 8. Examples include, but are not limited to, the following comonomers that can form the structure of X2: 1,2-octanediol, 1,2-nonanediol, 1,2-decanediol, 1,2-dodecane Diol, 1,2-tetradecanediol, 1,2-hexadecanediol. The more the number of carbon atoms, the better the adhesion between the cured epoxy resin and the reinforcing material, and the better the mechanical properties of the resulting composite material. However, if the number of carbon atoms is too large, the density of the cured epoxy resin will increase. Make the entire composite material denser, affecting its application. Preferably, said R1 is an alkyl group having 8-12 carbon atoms.

Further preferably, R in X2 also contains the following chemical structure:

Formula 5 can reduce the density of the cured epoxy resin and increase its mechanical strength. Wherein: R2, R3, R4 are H or alkyl. Examples include, but are not limited to, the following comonomers that can form the structure of X2: 2-ethyl-1,3-hexanediol, 2-ethyl-1,4-octanediol, 2,2-diethyl- 1,3-Hexanediol. The greater the number of carbon atoms, the lower the density of the cured epoxy resin, but the excessive number of carbon atoms will reduce the mechanical strength and chemical stability of the cured epoxy resin. Preferably, said R2 is an alkyl group with 1 to 4 carbon atoms, R3 is an alkyl group with 1 to 3 carbon atoms, and R4 is an alkyl group with 1 to 3 carbon atoms.

More preferably, when R in X2 includes the chemical structures of formula 4 and formula 5: the molar ratio of formula 4 to formula 5 is 1:0.1 to 0.4. Formula 5 Too much chemical structure content will reduce the mechanical properties of the cured epoxy resin, thereby reducing the strength and durability of the composite material, but too little content will increase the density of the cured epoxy resin, making the composite material denser .

Preferably, when X includes the chemical structures of X1 and X2: the molar ratio of X1 to X2 is 1:1 to 3, that is, when X1 is 100 mole fraction, X is 100 to 300 mole fraction. More X2 content can reduce the density of epoxy resin and achieve the purpose of light weight. However, too much X2 content will reduce the adhesion of epoxy resin to reinforcing materials, reduce the mechanical properties of composite materials, and reduce durability .

Preferably, the curing agent is at least one of acid anhydrides, carboxylic acids, and amines to ensure the impact on the mechanical properties and durability of the cured epoxy resin. Curing agent is a type of substance or mixture that promotes or controls the curing reaction. The curing reaction of epoxy resin is achieved by adding a curing agent, using certain groups in the curing agent to react with epoxy groups or hydroxyl groups in the epoxy resin. Achieved. The acid anhydride curing agent has a long service life after being mixed with the epoxy resin at room temperature, and the cured product has excellent properties, especially excellent dielectric properties. More preferably, the curing agent is an acid anhydride.

Preferably, the epoxy equivalent of the epoxy resin is above 1000 g/equivalent, and the higher the epoxy equivalent, the better the heat resistance of the epoxy resin.

Another object of the present invention is to provide a method for preparing a cured epoxy resin.

A preparation method of a cured epoxy resin includes:

(1). Preparation of epoxy resin:

Has the following chemical structure:

The raw materials of X1,,

It has the following chemical structure: -Raw material of X2 of RO, where: R in X2 is a group with no less than 4 carbon atoms and only containing carbon and hydrogen, with a molar ratio of 1:1 to 3, dissolved in a solvent, and added After the total mole fraction of each raw material is 0.5-1.5 times the epichlorohydrin mixed, an alkaline aqueous solution with a mass content of 20-40% is added to react until the epoxy equivalent is more than 1000g/equivalent, the liquids are separated and the finished product is obtained, and the finished product is condensed and solidified. Get epoxy resin,

(2) Preparation of cured epoxy resin: After dispersing the obtained epoxy resin with a dispersant, add a curing agent to obtain a glue solution, remove the dispersant at room temperature under vacuum conditions, and cure at 100-140°C for 3-6 Hours to obtain a cured epoxy resin.

Preferably, the solvent is a solvent capable of dispersing and dissolving the raw material containing X1 and the raw material containing X2 including toluene, xylene and the like.

Preferably, the alkaline aqueous solution includes potassium hydroxide and sodium hydroxide, preferably sodium hydroxide.

Preferably, the dispersant is acetone.

Another object of the present invention is to provide a composite material.

A composite material: it comprises the epoxy resin cured product and a reinforcing material.

Preferably, the reinforcing material contains at least one of carbon fiber and glass fiber.

Another object of the present invention is to provide a method for preparing composite materials.

A method for preparing a composite material includes:

After dispersing the epoxy resin with a dispersing agent, adding a curing agent to obtain a glue solution, impregnating the glue solution into the reinforcing material, and removing the dispersant from the impregnated reinforcing material at room temperature under vacuum conditions. Curing at 140°C for 20-40 minutes to obtain a prepreg. The prepreg is pressed to obtain a composite material.

Preferably, the dispersant is acetone.

Due to the application of the above technical solutions, the present invention has the following advantages and effects compared with the prior art:

The present invention is modified by a matrix resin, so that the density of the cured epoxy resin 1.10g / cm ³ or less, even at 1.00g / cm ³ or less, the drawing strength of greater than 2650MPa, the impact strength of greater than 20KJ / m ^2, manufactured by The obtained epoxy resin cured product and the reinforced material have good interface adhesion, which achieves the purpose of reducing the weight of the blade while maintaining the mechanical strength of the blade. The power generation capacity of the machine.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below in conjunction with embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments.

Epoxy resin. The epoxy equivalent of epoxy resin is above 1000g/equivalent. The higher the epoxy equivalent, the better the heat resistance of the epoxy resin. In this embodiment: the epoxy resin has the following chemical structure:

Where: X contains at least one of X1 and X2:

X1 has the following chemical structure:

X2 has the following chemical structure: -R-O formula 3,

X2 is a long-chain hydrocarbon group with the above chemical structure, which can reduce the density of the epoxy resin. The structure forming the X2 structure substance must contain two alcoholic hydroxyl groups, and the number of carbon atoms should not be less than 4. Examples, but not limited to, the following comonomers can form the X2 structure: butanediol, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, undecanediol , Tetradecanediol. The more the number of carbon atoms in R, the lower the density of the epoxy resin, but when the number of carbon atoms in R is greater than 10, its mechanical properties and durability will be reduced. R is an alkyl group having 4 to 10 carbon atoms, and R is an alkyl group having 4 to 6 carbon atoms.

The R in X2 contains the following chemical structure:

Formula 4 can improve the adhesion between the cured epoxy resin and the reinforcing material. Among them: R1 is an alkyl group, and the structure of the X2 structure containing formula 4 needs to contain two alcoholic hydroxyl groups at the 1st and 2nd positions, and the number of carbon atoms is not less than 8. Examples include, but are not limited to, the following comonomers that can form the structure of X2: 1,2-octanediol, 1,2-nonanediol, 1,2-decanediol, 1,2-dodecane Diol, 1,2-tetradecanediol, 1,2-hexadecanediol. The more the number of carbon atoms, the better the adhesion between the cured epoxy resin and the reinforcing material, and the better the mechanical properties of the resulting composite material. However, if the number of carbon atoms is too large, the density of the cured epoxy resin will increase. Make the entire composite material denser, affecting its application. R1 is an alkyl group having 8 to 12 carbon atoms.

The R in X2 also contains the following chemical structure:

Formula 5 can reduce the density of the cured epoxy resin and increase its mechanical strength. Wherein: R2, R3, R4 are H or alkyl. Examples include, but are not limited to, the following comonomers that can form the structure of X2: 2-ethyl-1,3-hexanediol, 2-ethyl-1,4-octanediol, 2,2-diethyl- 1,3-Hexanediol. The greater the number of carbon atoms, the lower the density of the cured epoxy resin, but the excessive number of carbon atoms will reduce the mechanical strength and chemical stability of the cured epoxy resin. R2 is an alkyl group having 1 to 4 carbon atoms, R3 is an alkyl group having 1 to 3 carbon atoms, and R4 is an alkyl group having 1 to 3 carbon atoms.

When R in X2 includes the chemical structures of formula 4 and formula 5: the molar ratio of formula 4 to formula 5 is 1:0.1 to 0.4. Formula 5 Too much chemical structure content will reduce the mechanical properties of the cured epoxy resin, thereby reducing the strength and durability of the composite material, but too little content will increase the density of the cured epoxy resin, making the composite material denser .

When X contains the chemical structures of X1 and X2: the molar ratio of X1 to X2 is 1:1 to 3, that is, when X1 is 100 mole fraction, X is 100 to 300 mole fraction. More X2 content can reduce the density of epoxy resin and achieve the purpose of light weight. However, too much X2 content will reduce the adhesion of epoxy resin to reinforcing materials, reduce the mechanical properties of composite materials, and reduce durability .

The curing agent is at least one of acid anhydrides, carboxylic acids, and amines to ensure the impact on the mechanical properties and durability of the cured epoxy resin. Curing agent is a type of substance or mixture that promotes or controls the curing reaction. The curing reaction of epoxy resin is achieved by adding a curing agent, using certain groups in the curing agent to react with epoxy groups or hydroxyl groups in the epoxy resin. Achieved. The acid anhydride curing agent has a long service life after being mixed with epoxy resin at room temperature. The cured product has excellent properties, especially excellent dielectric properties. The curing agent is an acid anhydride.

The preparation method of the above-mentioned cured epoxy resin includes:

(1). Preparation of epoxy resin:

Has the following chemical structure:

The raw materials of X1,,

It has the following chemical structure: -Raw material for X2 of RO, where: R in X2 is a group with no less than 4 carbon atoms and only containing carbon and hydrogen, and a molar ratio of 1:1 to 3, soluble in toluene and xylene In a solvent that can disperse and dissolve the raw materials containing X1 and the raw materials containing X2, add 0.5-1.5 times the total mole fraction of each raw material with epichlorohydrin and mix, then add a sodium hydroxide aqueous solution with a mass content of 20-40% to react to The epoxy equivalent is more than 1000g/equivalent, the liquid is separated and the finished product is obtained, and the finished product is condensed and solidified to obtain the epoxy resin.

(2) Preparation of cured epoxy resin: After dispersing the obtained epoxy resin with acetone, adding a curing agent to obtain a glue solution, after removing the acetone at room temperature under vacuum conditions, curing at 100-140°C for 3-6 hours, Obtain a cured epoxy resin.

A composite material: it contains a cured epoxy resin and a reinforcing material. Among them, the cured product containing epoxy resin is the cured product described above; the reinforcing material includes at least one of carbon fiber and glass fiber.

The preparation method of the above-mentioned composite material includes:

After dispersing the epoxy resin with acetone, add curing agent to obtain glue solution, impregnate the glue solution into the reinforcing material, remove the acetone from the impregnated reinforcing material at room temperature under vacuum conditions, and cure at 100-140°C for 20-40 minutes , Obtain a prepreg, press the prepreg to obtain a composite material.

Examples 1 to 11 are listed below for further description:

Example 1:

The epoxy resin of Example 1 was prepared, including:

Raw materials used: 100 mole fraction of bisphenol A, 200 mole fraction of octanediol,

Under the protection of nitrogen, the ratio of 100 mole fraction of bisphenol A and 200 mole fraction of octanediol was dissolved in toluene, and 1.05 times the total mole fraction of each raw material was added with epichlorohydrin. After the mixture was uniform, 30% hydrogen was added. After the sodium oxide aqueous solution is reacted for a certain time until the epoxy equivalent is about 2800±100g/equivalent, the liquid is separated by washing with distilled water, and the filtrate is refined with a rotary evaporator to obtain a finished product, and the finished product is condensed and solidified to obtain an epoxy resin.

After dispersing the above-prepared epoxy resin with acetone, add curing agent phthalic anhydride in the equivalent of epoxy group and acid anhydride group to obtain a glue solution. Then, after removing the acetone in a vacuum oven at room temperature, put it in 120 In an oven at ℃ for 4.5 hr, a cured epoxy resin was obtained.

After dispersing the epoxy resin prepared above with acetone, add the curing agent phthalic anhydride in the equivalent of epoxy group and acid anhydride group to obtain a glue solution, and then impregnate 20 layers of carbon fiber cloth (C06644B produced by Toray Co., Ltd.) with the glue solution. The width is 100cm, the thickness is 0.3mm, and the surface density is 317g/m2). Then, the immersed carbon fiber cloth is placed in a vacuum oven at room temperature to remove acetone, and then placed in an oven at 120°C for 30 minutes to obtain a prepreg. The molding machine presses the prepreg at 120° C. and 2 MPa for 4 hours to obtain a composite material.

Example 2:

Using raw materials: 100 mole fraction of bisphenol A, 100 mole fraction of octanediol,

Under the protection of nitrogen, the ratio of 100 mole fraction of bisphenol A and 100 mole fraction of octanediol was dissolved in toluene, and 1.05 times the total mole fraction of each raw material was added with epichlorohydrin. After the mixture was uniform, 30% hydrogen was added. After the sodium oxide aqueous solution is reacted for a certain time until the epoxy equivalent is about 2800±100g/equivalent, the liquid is separated by washing with distilled water, and the filtrate is refined with a rotary evaporator to obtain a finished product, and the finished product is condensed and solidified to obtain an epoxy resin.

Example 3:

Using raw materials: 100 mole fraction of bisphenol A, 300 mole fraction of octanediol,

Under the protection of nitrogen, the ratio of 100 mole fraction of bisphenol A and 300 mole fraction of octanediol was dissolved in toluene, and 1.05 times the total mole fraction of each raw material was added with epichlorohydrin. After the mixture was uniform, 30% hydrogen was added. After the sodium oxide aqueous solution is reacted for a certain time until the epoxy equivalent is about 2800±100g/equivalent, the liquid is separated by washing with distilled water, and the filtrate is refined with a rotary evaporator to obtain a finished product, and the finished product is condensed and solidified to obtain an epoxy resin.

Example 4:

Raw materials used: 100 mole fraction of bisphenol A, 200 mole fraction of undecanediol,

Under the protection of nitrogen, the ratio of 100 mole fraction of bisphenol A and 200 mole fraction of undecanediol was dissolved in toluene, and 1.05 times of the total mole fraction of each raw material was added with epichlorohydrin. After the mixture was uniform, 30% was added. After reacting with the sodium hydroxide aqueous solution for a certain period of time until the epoxy equivalent is about 2800±100g/equivalent, the liquid is separated by washing with distilled water, and the filtrate is refined with a rotary evaporator to obtain a finished product. The finished product is condensed and solidified to obtain an epoxy resin.

Example 5:

Using raw materials: 100 mole fraction of bisphenol A, 167 mole fraction of 1,2-dodecanediol, 33 mole fraction of 2,2,4-trimethyl-1,3-pentanediol,

Under the protection of nitrogen, the ratio of 100 mole fraction of bisphenol A, 167 mole fraction of 1,2-dodecanediol, and 33 mole fraction of 2,2,4-trimethyl-1,3-pentanediol was dissolved in toluene. And add 1.05 times the total mole fraction of each raw material with epichlorohydrin. After mixing evenly, add 30% sodium hydroxide aqueous solution to react for a certain period of time until the epoxy equivalent is about 2800±100g/equivalent, and then rinse with distilled water. After the filtrate is refined with a rotary evaporator, the finished product is obtained, and the finished product is condensed and solidified to obtain an epoxy resin.

After dispersing the above-prepared epoxy resin with acetone, add curing agent phthalic anhydride in the equivalent of epoxy group and acid anhydride group to obtain a glue solution. Then, after removing the acetone in a vacuum oven at room temperature, put it in 120 In an oven at °C for 4.5 hr, a cured epoxy resin was obtained.

Example 6:

Using raw materials: 100 mole fraction of bisphenol A, 182 mole fraction of 1,2-dodecanediol, 18 mole fraction of 2,2,4-trimethyl-1,3-pentanediol,

Under the protection of nitrogen, the ratio of 100 mole fraction of bisphenol A, 182 mole fraction of 1,2-dodecanediol, and 18 mole fraction of 2,2,4-trimethyl-1,3-pentanediol is dissolved in toluene. , And add 1.05 times the total mole fraction of each raw material epichlorohydrin, after mixing evenly, add 30% sodium hydroxide aqueous solution to react for a certain period of time until the epoxy equivalent is about 2800±100g/equivalent, and then wash and separate the liquid with distilled water After the filtrate is refined with a rotary evaporator, the finished product is obtained, and the finished product is condensed and solidified to obtain the epoxy resin.

Example 7:

Using raw materials: 100 mole fraction of bisphenol A, 143 mole fraction of 1,2-dodecanediol, 57 mole fraction of 2,2,4-trimethyl-1,3-pentanediol,

Under the protection of nitrogen, the ratio of 100 mole fraction of bisphenol A, 143 mole fraction of 1,2-dodecanediol, and 57 mole fraction of 2,2,4-trimethyl-1,3-pentanediol are dissolved in toluene. , And add 1.05 times the total mole fraction of each raw material epichlorohydrin, after mixing evenly, add 30% sodium hydroxide aqueous solution to react for a certain period of time until the epoxy equivalent is about 2800±100g/equivalent, and then wash and separate the liquid with distilled water After the filtrate is refined with a rotary evaporator, the finished product is obtained, and the finished product is condensed and solidified to obtain the epoxy resin.

Example 8:

Using raw materials: 100 mole fraction of bisphenol A, 167 mole fraction of 1,2-octanediol, 33 mole fraction of 2,2,4-trimethyl-1,3-pentanediol,

Under the protection of nitrogen, the ratio of 100 mole fraction of bisphenol A, 167 mole fraction of 1,2-octanediol and 33 mole fraction of 2,2,4-trimethyl-1,3-pentanediol is dissolved in toluene. And add 1.05 times the total mole fraction of each raw material with epichlorohydrin, after mixing uniformly, add 30% sodium hydroxide aqueous solution to react for a certain period of time until the epoxy equivalent is about 2800±100g/equivalent, then wash and separate the liquid with distilled water. After the filtrate is refined with a rotary evaporator, a finished product is obtained, and the finished product is condensed and solidified to obtain an epoxy resin.

Example 9:

Using raw materials: 100 mole fraction of bisphenol A, 167 mole fraction of 1,2-hexadecanediol, 33 mole fraction of 2,2,4-trimethyl-1,3-pentanediol,

Under the protection of nitrogen, the ratio of 100 mole fraction of bisphenol A, 167 mole fraction of 1,2-hexadecanediol and 33 mole fraction of 2,2,4-trimethyl-1,3-pentanediol is dissolved in toluene. , And add 1.05 times the total mole fraction of each raw material epichlorohydrin, after mixing evenly, add 30% sodium hydroxide aqueous solution to react for a certain period of time until the epoxy equivalent is about 2800±100g/equivalent, and then wash and separate the liquid with distilled water After the filtrate is refined with a rotary evaporator, the finished product is obtained, and the finished product is condensed and solidified to obtain the epoxy resin.

Example 10:

Using raw materials: 100 mole fraction of bisphenol A, 167 mole fraction of 1,2-dodecanediol, 33 mole fraction of 2-ethyl-1,3-hexanediol,

Under the protection of nitrogen, the ratio of 100 mole fraction of bisphenol A, 167 mole fraction of 1,2-dodecanediol, and 33 mole fraction of 2-ethyl-1,3-hexanediol are dissolved in toluene, and the raw materials are added. 1.05 times the total mole fraction of epichlorohydrin, after mixing uniformly, add 30% sodium hydroxide aqueous solution to react for a certain time until the epoxy equivalent is about 2800±100g/equivalent, wash with distilled water to separate the liquid, use a rotary evaporator After the filtrate is refined, the finished product is obtained, and the finished product is condensed and solidified to obtain an epoxy resin.

Example 11:

Using raw materials: 100 mole fraction of bisphenol A, 167 mole fraction of 1,2-octanediol, 33 mole fraction of 2-ethyl-1,3-hexanediol,

Under the protection of nitrogen, the ratio of 100 mole fraction of bisphenol A, 167 mole fraction of 1,2-octanediol, and 33 mole fraction of 2-ethyl-1,3-hexanediol is dissolved in toluene and added to the total of each raw material. 1.05 times the mole fraction of epichlorohydrin, after mixing uniformly, add 30% sodium hydroxide aqueous solution to react for a certain period of time until the epoxy equivalent is about 2800±100g/equivalent, wash with distilled water to separate the liquid, use a rotary evaporator to refine After the filtrate, the finished product is obtained, and the finished product is condensed and solidified to obtain an epoxy resin.

Comparative example 1:

EPICLON HM-091 produced by DIC Co., Ltd., bisphenol A epoxy resin, epoxy equivalent 2800g/equivalent. The cured epoxy resin and composite material were prepared in the same manner as in this embodiment.

The performance test methods are as follows:

Epoxy equivalent: tested according to GB/T 4612-2008.

Density of cured epoxy resin: scrape off the cured epoxy resin on the surface of the composite material, and be careful not to test the buoyancy method in the composite material in accordance with the GB/T1463-2005 standard.

Tensile strength: Tested according to ASTM D3039-08 standard, using a universal testing machine to determine the tensile strength.

Impact strength: In accordance with the GB/T1843-2008 standard, the unnotched impact method is used for testing.

Table 1: Comparison of performance parameters between Example 1 to Example 11 and Comparative Example 1.

Compared with the comparative example, the composite material prepared by using the epoxy resin cured product of the present invention has the characteristics of low density and high mechanical strength. It is suitable for use as a blade of a wind generator and can improve the power generation of the wind generator. .

The above-mentioned embodiments are only to illustrate the technical concept and characteristics of the present invention, and their purpose is to enable those familiar with the art to understand the content of the present invention and implement them accordingly, and should not limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit of the present invention should be covered by the protection scope of the present invention.

Claims

A cured epoxy resin, which is characterized in that it is prepared from raw materials containing an epoxy resin and a curing agent, wherein the epoxy resin: the epoxy resin has the following chemical structure:

Where: X contains at least one of X1 and X2:

X1 has the following chemical structure:

X2 has the following chemical structure:

Wherein: R in X2 is a group with no less than 4 carbon atoms and only containing carbon and hydrogen.
The cured epoxy resin according to claim 1, characterized in that: R in X2 contains the following chemical structure:

Wherein: R1 is an alkyl group with no less than 8 carbon atoms.
The cured epoxy resin according to claim 2, wherein said R1 is an alkyl group having 8-12 carbon atoms.
The cured epoxy resin according to claim 2, characterized in that: R in X2 also contains the following chemical structure:

Wherein: R2, R3, R4 are H or alkyl.
The cured epoxy resin according to claim 4, wherein said R2 is an alkyl group having 1 to 4 carbon atoms, R3 is an alkyl group having 1 to 3 carbon atoms, and R4 is an alkyl group having 1 to 3 carbon atoms. 1-3 alkyl groups.
The cured epoxy resin according to claim 4, wherein when R in X2 includes the chemical structure of formula 4 and formula 5, the molar ratio of formula 4 to formula 5 is 1:0.1 to 0.4.
The cured epoxy resin according to claim 1, wherein R is an alkyl group having 4 to 10 carbon atoms.
The cured epoxy resin according to claim 1, wherein X1 is a bisphenol A epoxy resin having a chemical structure of formula 2.
The cured epoxy resin according to claim 1, wherein when X includes the chemical structures of X1 and X2, the molar ratio of X1 and X2 is 1:1 to 3.
The cured epoxy resin according to claim 1, wherein the epoxy equivalent of the epoxy resin is more than 1000 g/equivalent.
The epoxy resin cured product according to claim 1, wherein the curing agent is at least one of acid anhydrides, carboxylic acids, and amines.
A cured epoxy resin, which is characterized in that it is prepared from raw materials containing an epoxy resin and a curing agent, wherein the epoxy resin: the epoxy resin has the following chemical structure:

Among them: X includes X1, X2, and the molar ratio of X1 to X2 is 1:1～3:

X1 has the following chemical structure:

X2 has the following chemical structure:

Among them: R in X2 is a group with no less than 4 carbon atoms and only containing carbon and hydrogen,

Wherein: R1 is an alkyl group with no less than 8 carbon atoms;

Among them: R2, R3, R4 are H or alkyl,

The molar ratio of formula 4 to formula 5 is 1:0.1～0.4;

The curing agent is at least one of acid anhydrides, carboxylic acids and amines.
A method for preparing a cured epoxy resin, which is characterized in that it comprises:

(1). Preparation of epoxy resin:

Has the following chemical structure:
The raw materials of X1,

Has the following chemical structure:
The raw material of X2, where: R in X2 is a group with no less than 4 carbon atoms and only containing carbon and hydrogen, and the molar ratio is 1:1 to 3 dissolved in the solvent, and the total mole fraction of each raw material is 0.5- After mixing 1.5 times the epichlorohydrin, add an alkaline aqueous solution with a mass content of 20-40% to react until the epoxy equivalent is more than 1000g/equivalent, separate the liquids and obtain the finished product, and condense and solidify the finished product to obtain the epoxy resin.

(2) Preparation of cured epoxy resin: After dispersing the obtained epoxy resin with a dispersant, add a curing agent to obtain a glue solution, remove the dispersant at room temperature under vacuum conditions, and cure at 100-140°C for 3-6 Hours to obtain a cured epoxy resin.
The method for preparing a cured epoxy resin according to claim 13, wherein the solvent is a solvent capable of dispersing and dissolving the raw material containing X1 and the raw material containing X2.
The method for preparing a cured epoxy resin according to claim 13, wherein the alkaline aqueous solution includes potassium hydroxide and sodium hydroxide.
The method for preparing a cured epoxy resin according to claim 13, wherein the dispersant is acetone.
A composite material: it is characterized in that it comprises the epoxy resin cured product according to any one of claims 1 to 11 and a reinforcing material.
The composite material according to claim 17, wherein the reinforcing material comprises at least one of carbon fiber and glass fiber.
A method for preparing a composite material, characterized in that: preparing the composite material according to claim 17, comprising: after dispersing the epoxy resin with a dispersant, adding a curing agent to obtain a glue solution, and immersing the glue solution For the reinforcing material, the impregnated reinforcing material is cured at 100-140°C for 20-40 minutes after removing the dispersant at room temperature under vacuum conditions to obtain a prepreg. The prepreg is pressed to obtain a composite material .
The method for preparing a composite material according to claim 19, wherein the dispersant is acetone.