阅读说明：本技术 新型低粘度生物基环氧树脂组合物及碳纤维复合材料 (Novel low-viscosity bio-based epoxy resin composition and carbon fiber composite material ) 是由 尚垒 敖玉辉 庄海林 刘浏 杜巍峰 马岩 石飞 郭宗伟 于 2019-11-20 设计创作，主要内容包括：本发明提供一种新型低粘度生物基环氧树脂组合物及碳纤维复合材料,属于环氧树脂组合物领域。该环氧树脂组合物,按照重量份数计,包括生物基环氧树脂100份,固化剂1-70份；所述的生物基环氧树脂,其具有式(1)所示的结构。本发明还提供一种碳纤维复合材料,按照重量份数计,包括：生物基环氧树脂15-30份,固化剂10-20份,促进剂0.1-0.3份,碳纤维材料25-50份,所述的生物基环氧树脂,其具有式(1)所示的结构。本发明的组合物具有优异的力学性能,且通过低粘度环氧树脂和碳纤维复合时,因其具有足够低的粘度提高了其与碳纤维的浸润性,以及足够多的环氧官能团有利于提高与碳纤维的界面粘合性。(The invention provides a novel low-viscosity bio-based epoxy resin composition and a carbon fiber composite material, and belongs to the field of epoxy resin compositions. The epoxy resin composition comprises 100 parts of bio-based epoxy resin and 1-70 parts of curing agent by weight; the bio-based epoxy resin has a structure shown in a formula (1). The invention also provides a carbon fiber composite material which comprises the following components in parts by weight: 15-30 parts of bio-based epoxy resin, 10-20 parts of curing agent, 0.1-0.3 part of accelerator and 25-50 parts of carbon fiber material, wherein the bio-based epoxy resin has a structure shown in a formula (1). The composition has excellent mechanical property, and when the low-viscosity epoxy resin and the carbon fiber are compounded, the wettability of the low-viscosity epoxy resin and the carbon fiber is improved due to the low enough viscosity, and the interface adhesiveness of the low-viscosity epoxy resin and the carbon fiber is favorably improved due to enough epoxy functional groups.)

1. A novel low-viscosity biological epoxy resin composition is characterized by comprising the following components in parts by weight

100 parts of bio-based epoxy resin and 1-70 parts of curing agent;

the bio-based epoxy resin has a structure shown in a formula (1):

the curing agent is an acid anhydride curing agent or an amine curing agent.

2. The novel low viscosity bio-based epoxy resin composition as claimed in claim 1, wherein said anhydride curing agent is methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, maleic anhydride, phthalic anhydride or citric anhydride.

3. The novel low viscosity bio-based epoxy resin composition of claim 1, wherein said amine curing agent is diaminodiphenylmethane, diethylenetriamine or diaminodiphenylsulfone.

4. The novel low viscosity bio-based epoxy resin composition as claimed in claim 1, wherein said composition further comprises an accelerator.

5. The novel low viscosity bio-based epoxy resin composition as claimed in claim 1, wherein said accelerator is any one of triethylamine, tris (dimethylaminomethyl) phenol, 2-ethyl-4-methylimidazole.

6. The carbon fiber composite material is characterized by comprising the following components in parts by weight:

the bio-based epoxy resin has a structure shown in a formula (1):

the curing agent is an acid anhydride curing agent or an amine curing agent.

7. The carbon fiber composite material as claimed in claim 6, wherein the acid anhydride curing agent is methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, maleic anhydride, phthalic anhydride or citric anhydride.

8. The carbon fiber composite material according to claim 6, wherein the amine curing agent is diaminodiphenylmethane (DDM), diethylenetriamine, or diaminodiphenylsulfone.

9. The carbon fiber composite material as claimed in claim 6, wherein the accelerator is any one of triethylamine, tris (dimethylaminomethyl) phenol, and 2-ethyl-4-methylimidazole.

Technical Field

The invention belongs to the field of epoxy resin compositions, and particularly relates to a novel low-viscosity bio-based epoxy resin composition and a carbon fiber composite material.

Background

The Carbon Fiber (CF) is a special fiber with high carbon content prepared by carbonizing organic fiber in inert gas at high temperature, has the intrinsic characteristics of carbon material and forms a fibrous, soft and additive fabric, and is a new generation of reinforced fiber. The carbon fiber has the excellent performances of high strength, high modulus, high temperature resistance, low density, friction resistance, corrosion resistance, electric conduction, heat conduction and the like. Because of the preferred orientation of the graphite crystallite structure along the fiber axis, the fiber has high strength and modulus along the fiber axis, and the weight of the fiber is less than 1/4 of steel under the condition of the same volume. The tensile strength of the carbon fiber resin composite material is generally more than 3500MPa, which is 7-9 times of that of steel, and the tensile elastic modulus of 230-430 GPa is also higher than that of steel. The specific strength and specific modulus of the carbon fiber resin composite material are the highest among the existing engineering materials. The higher the specific modulus of the material, the greater the strength of the member, and the higher the specific strength, the smaller the member's own weight. Due to its unique properties, advanced carbon fiber composites play an important role in the fields of aerospace, military, automotive, construction, and the like.

However, since carbon fibers are carbon materials having a carbon content of 90% or more, which are produced by carbonizing carbon fibers at a high temperature of 1300 to 1600 ℃, they are carbonized in a high-temperature inert gas, and their surface activity is reduced, surface tension is reduced, and wettability with a resin matrix is deteriorated due to escape of non-carbon elements and enrichment of carbon. In addition, in order to increase the tensile strength of the carbon fiber, it is necessary to reduce surface defects as much as possible, and therefore, the surface volume thereof is also small. The smooth surface makes the anchoring and mechanical bonding effect with the resin matrix weaker, which results in the reduction of the interlaminar shear strength of the composite material, so that when the carbon fiber is used as an enhancing material to prepare the composite material, the carbon fiber is generally required to be subjected to surface modification treatment. Therefore, the selection and design of the matrix resin are particularly critical, so that the strength of the carbon fiber can be maintained, and the method has important significance for preparing carbon fiber composite materials and carbon fiber functional materials. At present, most of the carbon fiber/epoxy resin composite materials known in the market take bisphenol A type epoxy resin or modified bisphenol A type epoxy resin as a resin matrix, and then are combined with carbon fibers and cured to prepare the carbon fiber composite material. However, the composite material has disadvantages that, on one hand, the carbon fiber has low surface activity and reduced surface tension, which deteriorates the wettability of the carbon fiber with the resin matrix, and on the other hand, bisphenol a type epoxy resin is derived from petroleum resources, and as the petroleum resources are increasingly depleted, the search for renewable resources as main raw materials is not easy. Therefore, the problem of wettability of the carbon fiber composite material and the resin matrix and the problem of renewable utilization of the resin matrix are solved, so that the carbon fiber composite material is developed towards environmental coordination, and the carbon fiber composite material is a hot field for intensive research of researchers of composite materials at home and abroad at present.

At present, the surface treatment method of carbon fiber mainly comprises the following steps: oxidation treatment, plasma treatment, chemical grafting treatment, sizing treatment and the like. However, these conventional surface treatment methods have significant advantages and disadvantages. Such as chemical treatment, can increase the active groups on the surface of the carbon fiber, thereby enhancing the interaction with the matrix: but often damage the carbon fibers and reduce their strength. The physical sizing method can prevent the carbon fiber from fluffing in the transportation and processing processes and has no influence on the mechanical property, and even can improve the following properties: however, sizing often fails to provide strong chemical interaction of the carbon fibers with the matrix. Patent CN107057283A and patent CN106046682A disclose methods for improving the interfacial bonding force between carbon fiber and epoxy resin, respectively, but expensive raw materials such as graphene and carbon nanotube are used, and the practicability is insufficient; and these nanomaterials have poor dispersibility in composites. Patents CN110172228A and CN110172229 disclose preparation methods of lignin epoxy resin/carbon fiber reinforced composite respectively, but the prepared lignin epoxy resin is solid and needs to be heated and melted, which increases the processing difficulty.

Disclosure of Invention

The invention aims to provide a novel low-viscosity bio-based epoxy resin composition and a carbon fiber composite material, wherein the composition has excellent mechanical properties, and when low-viscosity epoxy resin and carbon fiber are compounded, the wettability of the low-viscosity bio-based epoxy resin composition and the carbon fiber is improved due to the low enough viscosity, and enough epoxy functional groups are beneficial to improving the interfacial adhesion of the low-viscosity bio-based epoxy resin composition and the carbon fiber.

The invention firstly provides a novel low-viscosity biological epoxy resin composition which comprises the following components in parts by weight

100 parts of bio-based epoxy resin and 1-70 parts of curing agent;

the bio-based epoxy resin has a structure shown in a formula (1):

the curing agent is an acid anhydride curing agent or an amine curing agent.

Preferably, the acid anhydride curing agent is methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, maleic anhydride, phthalic anhydride or citric anhydride.

Preferably, the amine curing agent is diaminodiphenylmethane (DDM), diethylenetriamine or diaminodiphenylsulfone.

Preferably, the composition further comprises an accelerator.

Preferably, the accelerator is any one of triethylamine, tris (dimethylaminomethyl) phenol, and 2-ethyl-4-methylimidazole.

The invention also provides a carbon fiber composite material which comprises the following components in parts by weight:

the bio-based epoxy resin has a structure shown in a formula (1):

the curing agent is an acid anhydride curing agent or an amine curing agent.

Preferably, the acid anhydride curing agent is methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, maleic anhydride, phthalic anhydride or citric anhydride.

Preferably, the amine curing agent is diaminodiphenylmethane (DDM), diethylenetriamine or diaminodiphenylsulfone.

Preferably, the accelerator is any one of triethylamine, tris (dimethylaminomethyl) phenol, and 2-ethyl-4-methylimidazole.

The invention has the advantages of

The invention firstly provides a novel low-viscosity bio-based epoxy resin composition which comprises 100 parts of bio-based epoxy resin and 1-70 parts of curing agent in parts by weight; the bio-based epoxy resin has a structure shown in a formula (1), and the curing agent is an anhydride curing agent or an amine curing agent. Compared with the prior art, each epoxy monomer of the bio-based epoxy resin has six epoxy functional groups, so that the mechanical property of the material is greatly improved, and the bio-based epoxy resin composition has a larger application space. Meanwhile, the main raw materials of the bio-based epoxy resin are all from bio-based renewable resources, and the bio-based epoxy resin has a certain positive effect on relieving the petroleum crisis and reducing the emission of carbon dioxide; and the main raw materials are green and nontoxic substances, so that the pollution to the environment is reduced while the damage to the human body is reduced, and the industrial application is facilitated.

The invention also provides a carbon fiber composite material which comprises the following components in parts by weight: 15-30 parts of bio-based epoxy resin, 25-50 parts of carbon fiber material, 10-20 parts of curing agent and 0.1-0.3 part of accelerating agent, wherein the bio-based epoxy resin has a structure shown in a formula (1), compared with the prior art, the bio-based epoxy resin has the advantages that the wettability of the resin and the carbon fiber is improved due to lower viscosity, each epoxy monomer has six epoxy functional groups, the two advantages are achieved, the adhesion of the resin and the carbon fiber is greatly improved, the mechanical property of the carbon fiber composite material is improved, and the application in the carbon fiber composite material is facilitated.

Drawings

FIG. 1 is a chart of the infrared spectra of various products of the preparation of example 1 according to the invention;

FIG. 2 is a NMR spectrum of product 1 of example 1;

FIG. 3 is a NMR spectrum of product 3 of example 1;

FIG. 4 is a NMR spectrum of product 4 of example 1;

FIG. 5 is a NMR spectrum of product 5 of example 1.

Detailed Description

The invention firstly provides a novel low-viscosity biological epoxy resin composition which comprises the following components in parts by weight:

100 parts of bio-based epoxy resin and 1-70 parts of curing agent;

the bio-based epoxy resin has a structure shown in a formula (1):

the curing agent is an acid anhydride curing agent or an amine curing agent. The acid anhydride curing agent is preferably methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, maleic anhydride, phthalic anhydride or citric anhydride. The amine curing agent is preferably diaminodiphenylmethane (DDM), diethylenetriamine or diaminodiphenylsulfone.

According to the invention, the composition also comprises an accelerator, and the accelerator is preferably any one of triethylamine, tris (dimethylaminomethyl) phenol and 2-ethyl-4-methylimidazole. The addition part of the accelerator is preferably 0.1 to 0.3 part by weight.

According to the present invention, the novel low viscosity bio-based epoxy resin composition preferably comprises, in parts by weight: 100 parts of bio-based epoxy resin, 60 parts of methyltetrahydrophthalic anhydride and 0.2 part of tris (dimethylaminomethyl) phenol.

According to the present invention, the novel low viscosity bio-based epoxy resin composition preferably comprises, in parts by weight: 100 parts of bio-based epoxy resin and 15 parts of diaminodiphenylmethane.

The invention relates to a preparation method of a low-viscosity bio-based epoxy resin composition, which comprises the following steps:

the method comprises the following steps: mixing the raw materials; the mixing can be directly mixed according to different types of curing agents, or when the curing agent is an amine curing agent, the amine curing agent and the bio-based epoxy resin can be respectively heated and then mixed; the heating temperature is preferably 60-90 ℃;

step two: curing the fully mixed raw materials at 60-90 ℃ for 2-6 hours, then curing at 91-120 ℃ for 2-6 hours, and then curing at 121-150 ℃ for 3-5 hours to obtain the low-viscosity bio-based epoxy resin composition.

The invention also provides a carbon fiber composite material which comprises the following components in parts by weight:

the bio-based epoxy resin has a structure shown in a formula (1):

the curing agent is an acid anhydride curing agent or an amine curing agent. The acid anhydride curing agent is preferably methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, maleic anhydride, phthalic anhydride or citric anhydride. The amine curing agent is preferably diaminodiphenylmethane (DDM), diethylenetriamine or diaminodiphenylsulfone.

According to the invention, the composition also comprises an accelerator, and the accelerator is preferably any one of triethylamine, tris (dimethylaminomethyl) phenol and 2-ethyl-4-methylimidazole.

The invention relates to a preparation method of a carbon fiber composite material. The method comprises the following steps:

1. mixing bio-based epoxy resin, a curing agent and an accelerant according to the proportion to prepare a bio-based epoxy resin composition, and removing bubbles under a vacuum condition;

2. cutting carbon fibers into a certain size, laying the carbon fibers in a vacuum bag, and introducing the prepared bio-based epoxy resin into the carbon fibers under a vacuum condition; 3 carbon fiber plates are manufactured by 3k carbon fiber cloth with the cutting strength grade of T300 of the carbon fibers, 12 layers of carbon fiber cloth are laid on each plate, 36 layers of carbon fiber cloth are cut in total, and the size of each layer of carbon fiber cloth is 150 multiplied by 120 mm;

3. and (3) putting the bio-based epoxy resin/carbon fiber composite material into an oven, curing at the temperature of 60-150 ℃ for 2-8 hours, and finishing curing to obtain the composite material.

According to the present invention, the preparation method of the bio-based epoxy resin preferably comprises:

step one, adding a solvent, glycerol, itaconic acid and methanesulfonic acid into a reaction vessel under the protection of nitrogen, and then reacting for 5-10 hours at the temperature of 140-160 ℃, wherein the molar ratio of the glycerol to the itaconic acid is preferably 1:3-5, and the mass of a catalyst methanesulfonic acid is 0.15 wt%; the selected solvent is preferably toluene, and the reaction route is as follows:

step two: adding the product 1, a solvent and DMF into a reaction vessel, placing the mixture in an ice water bath at 0 ℃ for stirring, wherein the stirring speed is preferably 300-400r/min, then dripping oxalyl chloride, slowly heating the reaction mixture, reacting at 20-70 ℃ for 3-5 hours until the solid is completely dissolved, and then performing rotary evaporation on the obtained solution at preferably 40-60 ℃ to obtain a product 2; the mol ratio of the product 1 to the oxalyl chloride is preferably 1: 3-4; the solvent is preferably one of anhydrous tetrahydrofuran or anhydrous dichloromethane;

step three: adding vanillin and triethylamine into a reaction vessel to be dissolved in a solvent, placing the mixture into an ice water bath to be stirred, wherein the stirring speed is preferably 300-400r/min, then dissolving the product 2 obtained in the step two into ethyl acetate to obtain a solution, dripping the solution into the reaction vessel within 10-20min, keeping the reaction vessel at 20-50 ℃ for 20-60min, preferably filtering the reaction solution after the reaction, removing the solvent through a rotary evaporation method, extracting the solution with dichloromethane after the water boiling, removing the solvent through the rotary evaporation method again, and performing vacuum drying at 80-100 ℃ for 3-10 hours to obtain a product 3; the molar ratio of the product 2 to the vanillin to the triethylamine is 1: 3-4: 3-4; the solvent is preferably ethyl acetate: the reaction route is as follows:

step four: after the product 3 and hot phenol are added to a reaction vessel at 60-80 ℃ to obtain a homogeneous solution, p-toluenesulfonic acid and zinc chloride are added and the temperature is maintained at 30-70 ℃ for reaction for 12-36 hours, after which the mixture is preferably washed 3-5 times with hot water (>70 ℃) to remove residual salts. Most of the unreacted phenol was removed by distillation at 100 ℃ and 150 ℃ under reduced pressure. The crude product obtained was dissolved in ethanol and precipitated into water with vigorous stirring. Collecting the precipitate and vacuum drying at 80-110 deg.c to obtain product 4; the molar ratio of the product 3 to the hot phenol is 1: 6-12; the molar ratio of p-toluenesulfonic acid, zinc chloride and product 3 was 4: 1; the reaction route is as follows:

step five: adding the product 4 and epichlorohydrin into a reaction vessel, stirring and heating to 90-120 ℃, adding tetrabutylammonium bromide after the product 4 is completely dissolved, allowing the mixture to react at 90-120 ℃ for 4-6 hours, when the mixture is cooled to 30-60 ℃, then dropwise adding a NaOH solution within 1-2 hours, keeping the obtained mixture at 30-70 ℃ for 3-6 hours, preferably cooling to room temperature, and washing the mixture 3-5 times with water to remove residual salts. Most of the unreacted epichlorohydrin was removed by rotary evaporation at 70-100 ℃ and dried under vacuum at 80-100 ℃ to obtain a low viscosity bio-based epoxy resin based on vanillin. The molar ratio of the product 4 to the epichlorohydrin is preferably 1: 50-66, and the preferable adding amount of the tetrabutylammonium bromide is 2-6 wt% of the product 4. The reaction route is as follows:

the present invention is described in further detail below with reference to examples, in which the starting materials are all commercially available.