Epoxy resin material based on two-dimensional aromatic polyamide and preparation method thereof

Abstract

The invention relates to the technical field of epoxy resin materials, and discloses an epoxy resin material based on two-dimensional aromatic polyamide and a preparation method thereof.The preparation method comprises the specific preparation steps that firstly, melamine reacts with 1, 3, 5-trimesoyl chloride, washing, centrifuging and drying are performed to obtain two-dimensional aromatic polyamide, and the two-dimensional aromatic polyamide is ground into nano powder; secondly, adding the nano powder according to 0.5% of the mass of the amine curing agent, and performing ultrasonic dispersion to form a homogeneous-phase enhanced curing agent; and finally, blending the bisphenol A resin E51, the perfluorooctanoyl chloride modified melamine and the amine curing agent containing the two-dimensional aromatic polyamide to obtain the epoxy resin material. The two-dimensional aromatic polyamide epoxy resin material disclosed by the invention has relatively good mechanical property and waterproof property.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of epoxy resin materials, in particular to an epoxy resin material based on two-dimensional polyaramid and a preparation method thereof. BACKGROUND

[0002] Epoxy resin is a kind of thermosetting resin with excellent adhesion, electrical insulation and chemical stability, which is widely used in the fields of coatings, adhesives, electronic packaging materials and structural composites. However, the cured pure epoxy resin has defects such as high brittleness and poor impact resistance, which greatly limits its application field.

[0003] The existing technology adopts modification methods such as fiber reinforcement and nanoparticle filling. Among them, two-dimensional nanomaterials (such as graphene) are widely used as reinforcing phases of epoxy resin due to their large specific surface area and excellent mechanical properties, but graphene materials have problems such as high cost and poor compatibility with epoxy resin. Traditional one-dimensional fiber reinforcement can improve the mechanical properties, but it will lead to the decline of the processability of the material.

[0004] Polyaramid has the characteristics of high-strength and high-modulus aromatic polymer. The aromatic ring structure and amide bond in the molecular chain of polyaramid endow the material with excellent stability. By preparing two-dimensional nanosheets from polyaramid, the barrier effect and interfacial interaction of the sheet structure can be utilized to enhance the epoxy resin. Based on the defects of the performance deficiency of the existing technology, an epoxy resin material based on two-dimensional polyaramid with excellent mechanical properties and barrier properties is provided. SUMMARY

[0005] Technical problems to be solved In view of the shortcomings of the prior art, the present application provides an epoxy resin material based on two-dimensional polyaramid and a preparation method thereof. The material has good mechanical properties and waterproof properties.

[0006] Technical scheme To achieve the above-mentioned purpose, the present application provides the following technical scheme: a preparation method of an epoxy resin material based on two-dimensional polyaramid, comprising the following steps: S1. Melamine and 1,3,5-benzene tricarbonyl chloride are added to a reaction bottle, then 4-5 mL of pyridine and 40-42 mL of N-methyl pyrrolidone are added in turn, and the reaction is stirred at room temperature for 30-35 h to obtain a crude product. The crude product is washed with anhydrous ethanol, ultrapure water and acetone in turn, and then ultrasonic is applied for 25-30 min. Then, centrifugation is carried out at a speed of 8000-10000 r / min for 4-6 min to separate the solid and liquid phases, and the solid is retained. According to the above process, each kind of solvent is washed for 2-3 times. Finally, vacuum drying is carried out at 65-70℃ for 15-18 h, and then the temperature is cooled to room temperature to obtain two-dimensional polyaramid; S2. Grinding the two-dimensional polyaramid obtained in S1 to a particle size of nanoscale to obtain a two-dimensional polyaramid powder; S3. Weighing 100-110 mmol of amine curing agent, adding two-dimensional polyaramid powder according to 0.5% by mass, then placing it in an ultrasonic water bath to disperse to a solution with ultrasonic oscillation at a power of 280-300 W to become homogeneous, forming an amine curing agent containing two-dimensional polyaramid; S4. Adding 45-50 g of N,N-dimethylformamide solvent, triethylamine, melamine to the reaction bottle, stirring and mixing uniformly, continuing to add perfluorooctanoyl chloride, completing the dropwise addition within 4-6 min, reacting at 36-40℃, after the reaction is completed, the obtained reaction mixture is centrifuged to separate the solid precipitate, then washed with N,N-dimethylformamide and distilled water until the filtrate is colorless and transparent, then the obtained precipitate is alternately ultrasonically washed and centrifugally separated to obtain a solid material, which is placed in a vacuum drying oven at 80-85℃ for 6-8h to obtain perfluorooctanoyl chloride modified melamine; S5. Adding 80-100 parts by weight of bisphenol A type high viscosity resin E51, 3-5 parts by weight of perfluorooctanoyl chloride modified melamine, and 35-45 parts by weight of amine curing agent containing two-dimensional polyaramid to the reactor, stirring thoroughly, and ultrasonic defoaming to obtain a bubble-free pre-crosslinked epoxy resin, which is cured to obtain a two-dimensional polyaramid-based epoxy resin material.

[0007] Further, in S1, the mass ratio of melamine to 1,3,5-benzene tricarbonyl chloride is 0.61-0.64 g: 1.31-1.34 g.

[0008] Further, in S2, the particle size is 60-80 nm.

[0009] Further, in S3, the amine curing agent is any one of ethylenediamine, diethylenetriamine, methyltetrahydrophthalic anhydride, and dicyandiamide.

[0010] Further, in S4, the amount ratio of triethylamine, melamine, and perfluorooctanoyl chloride is 80-100 mmol: 80-110 mmol: 80-110 mmol.

[0011] Further, in S4, the reaction time is 10-13 h.

[0012] Further, in S5, the curing temperature is 100-165℃.

[0013] Further, in S5, the curing time is 10-12 h.

[0014] Further, it is prepared by any one of claims 1-8.

[0015] Beneficial technical effects The two-dimensional polyaramid has good mechanical properties, and after being added into the epoxy resin as a reinforcing phase, a "three-dimensional support network" can be constructed in the epoxy resin matrix. The rigid aromatic rings in the molecular chain and the strong hydrogen bond effect make the material not only transmit stress but also inhibit deformation, thus achieving good mechanical effect. Compared with the modification methods of fiber reinforcement, nanoparticle filling and the like in the prior art, the agglomeration risk is reduced, the mechanical properties and hydrophobicity are improved, and the cost is reduced. The two-dimensional polyaramid nanosheet is uniformly dispersed in the epoxy matrix, effectively improves the glass transition temperature of the composite material, and significantly enhances the interface interaction and inhibits the expansion of microcracks. In the present application, a polyamine or an acid anhydride curing agent is used, which not only forms a dense crosslinked network with the epoxy resin, but also has a π-π stacking effect with the two-dimensional polyaramid, further strengthening the interface bonding, and effectively improving the defects of "brittleness and easy breaking" of traditional epoxy resin.

[0016] Step S4 prepares perfluorooctanoyl chloride modified melamine by reacting melamine with perfluorooctanoyl chloride. The perfluorooctyl group in the perfluorooctanoyl chloride molecule has extremely low surface energy and is a typical hydrophobic group. The modified melamine has a large number of perfluorooctyl groups grafted on the surface, which can form a hydrophobic layer on the surface of the epoxy resin material, significantly increasing the water contact angle of the material and effectively reducing the water absorption of the material.

[0017] The interface interaction between the perfluorooctanoyl chloride modified melamine surface and the epoxy resin matrix, the amino group of the melamine can react with the epoxy group of the epoxy resin, and the interface bonding force is enhanced. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is the reaction route of perfluorooctanoyl chloride modified melamine. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0020] In order to better understand the above technical scheme, the above technical scheme will be described in detail below in combination with the drawings in the specification and specific embodiments.

[0021] Embodiment 1 A preparation method of an epoxy resin material based on two-dimensional polyaramid, comprising the following steps: S1. 0.61 g of melamine and 1.31 g of 1,3,5-benzene tricarbonyl chloride were added to a reaction bottle, then 4 mL of pyridine and 40 mL of N-methyl pyrrolidone were added in turn, and the reaction was stirred at room temperature for 30 h to obtain a crude product, which was washed with anhydrous ethanol, ultrapure water and acetone in turn, ultrasonic for 25 min, then centrifuged at 8000 r / min for 4 min to separate the solid and liquid phases, and the solid was retained. According to the above process, each solvent was washed 2 times, and finally dried at 65°C under vacuum for 15 h, cooled to room temperature, and a two-dimensional polyaramid was obtained; S2. The two-dimensional polyaramid obtained in S1 was ground to a particle size of 60 nm to obtain a two-dimensional polyaramid powder; S3. 100 mmol of amine curing agent diethylenetriamine was weighed, 0.5% of two-dimensional polyaramid powder was added according to the mass fraction, then it was placed in an ultrasonic water bath to disperse and ultrasonic oscillation to a homogeneous solution to form an amine curing agent containing two-dimensional polyaramid; S4. 45 g of N,N-dimethylformamide solvent, 80 mmol of triethylamine, 80 mmol of melamine were added to a reaction bottle, stirred and mixed uniformly, and then 80 mmol of perfluorooctanoyl chloride was added dropwise, which was completed within 4 min. The reaction was carried out at 36°C for 10 h. After the reaction was completed, the obtained reaction mixture was centrifuged to separate the solid precipitate, which was then washed with N,N-dimethylformamide and distilled water until the filtrate was colorless and transparent. Subsequently, the obtained precipitate was alternately ultrasonically washed and centrifugally precipitated and separated with dichloromethane and acetone, and the obtained solid was placed in a vacuum drying oven at 80°C for drying for 6 h to obtain perfluorooctanoyl chloride modified melamine; S5. 80 parts by weight of bisphenol A type high viscosity resin E51, 3 parts by weight of perfluorooctanoyl chloride modified melamine, and 35 parts by weight of amine curing agent containing two-dimensional polyaramid were added to a reactor, stirred thoroughly, and ultrasonically degassed to obtain a bubble-free pre-crosslinked epoxy resin. Curing at 100°C for 10 h obtained a two-dimensional polyaramid-based epoxy resin material.

[0022] Example 2 A method for preparing a two-dimensional polyaramid-based epoxy resin material, comprising the following steps: S1. 0.64 g of melamine and 1.34 g of 1,3,5-benzene tricarbonyl chloride were added to a reaction bottle, then 5 mL of pyridine and 42 mL of N-methyl pyrrolidone were added in turn, and the reaction was stirred at room temperature for 35 h to obtain a crude product, which was washed with anhydrous ethanol, ultrapure water and acetone in turn, ultrasonic for 30 min, then centrifuged at 10000 r / min for 6 min to separate the solid and liquid phases, and the solid was retained. According to the above process, each solvent was washed 3 times, and finally dried at 70°C under vacuum for 18 h, cooled to room temperature, and a two-dimensional polyaramid was obtained; S2. Grinding the two-dimensional polyaramid obtained in S1 to a particle size of 80 nm to obtain a two-dimensional polyaramid powder; S3. Taking 110 mmol of amine curing agent methyl tetrahydrophthalic anhydride, adding two-dimensional polyaramid powder at a mass fraction of 0.5%, and then placing it in an ultrasonic water bath to disperse to a solution at a power of 300 W to become homogeneous, forming an amine curing agent containing two-dimensional polyaramid; S4. Adding 50 g of N,N-dimethylformamide solvent, 100 mmol of triethylamine, and 110 mmol of melamine to the reaction bottle, stirring to mix uniformly, and continuing to add 110 mmol of perfluorooctanoyl chloride, which is completed within 4-6 min, and reacting at 40°C for 13 h. After the reaction is completed, the obtained reaction mixture is centrifuged to separate the solid precipitate, which is then washed and centrifuged with N,N-dimethylformamide and distilled water until the filtrate is colorless and transparent, and then the obtained precipitate is alternately ultrasonically washed and centrifugally separated with dichloromethane and acetone, and the obtained solid is placed in a vacuum drying oven at 85°C for drying for 8 h to obtain perfluorooctanoyl chloride modified melamine; S5. Adding 100 parts by weight of bisphenol A type high viscosity resin E51, 5 parts by weight of perfluorooctanoyl chloride modified melamine, and 45 parts by weight of amine curing agent containing two-dimensional polyaramid to the reactor, stirring thoroughly, and ultrasonically defoaming to obtain a bubble-free pre-crosslinked epoxy resin, which is cured at 150°C for 12 h to obtain a two-dimensional polyaramid-based epoxy resin material.

[0023] Example 3 A method for preparing a two-dimensional polyaramid-based epoxy resin material, comprising the following steps: S1. Adding 0.62 g of melamine and 1.33 g of 1,3,5-benzene tricarbonyl chloride to a reaction bottle, and then sequentially adding 4.5 mL of pyridine and 41 mL of N-methyl pyrrolidone, stirring at room temperature for 33 h to obtain a crude product, which is washed with anhydrous ethanol, ultrapure water, and acetone, respectively, ultrasonically for 27 min, and then centrifuged at 9000 r / min for 5 min to separate the solid and liquid phases, and the solid is retained. According to the above process, each solvent is washed twice, and finally the two-dimensional polyaramid is obtained by vacuum drying at 68°C for 17 h and cooling to room temperature; S2. Grinding the two-dimensional polyaramid obtained in S1 to a particle size of 70 nm to obtain a two-dimensional polyaramid powder; S3. Taking 105 mmol of amine curing agent dicyandiamide, adding two-dimensional polyaramid powder at a mass fraction of 0.5%, and then placing it in an ultrasonic water bath to disperse to a solution at a power of 290 W to become homogeneous, forming an amine curing agent containing two-dimensional polyaramid; S4. Add 48 g of N,N-dimethylformamide solvent, 90 mmol of triethylamine, 100 mmol of melamine to the reaction bottle, stir and mix uniformly, continue to add 100 mmol of perfluorooctanoyl chloride, dropwise addition is completed within 5 min, reaction at 38°C for 12 h, after the reaction is completed, the obtained reaction mixture is centrifuged, and the solid precipitate is separated out, then washed with N,N-dimethylformamide and distilled water and centrifuged until the filtrate is colorless and transparent, then the obtained precipitate is alternately ultrasonically washed and centrifugally precipitated and separated, the obtained solid is placed in a vacuum drying oven at 83°C and dried for 7 h, to obtain perfluorooctanoyl chloride modified melamine; S5. Add 90 parts by weight of bisphenol A type high viscosity resin E51, 4 parts by weight of perfluorooctanoyl chloride modified melamine, and 40 parts by weight of amine curing agent containing two-dimensional polyaramide into a reactor, stir thoroughly, and ultrasonically defoam to obtain a bubble-free pre-crosslinked epoxy resin, and cure at 165°C for 11 h to obtain a two-dimensional polyaramide-based epoxy resin material.

[0024] Example 4 A method for preparing a two-dimensional polyaramide-based epoxy resin material, comprising the following steps: S1. Add 0.61 g of melamine and 1.31 g of 1,3,5-benzene tricarbonyl chloride into a reaction bottle, then add 4 mL of pyridine and 40 mL of N-methyl pyrrolidone in sequence, stir and react at room temperature for 30 h to obtain a crude product, wash with anhydrous ethanol, ultrapure water and acetone in sequence, ultrasonically wash for 25 min, then centrifuge at a speed of 8000 r / min for 4 min to separate the solid and liquid phases, retain the solid, and wash with each solvent for 2 times according to the above process, and finally dry at 65°C under vacuum for 15 h, cool to room temperature, and obtain two-dimensional polyaramide; S2. Grind the two-dimensional polyaramide obtained in S1 to a particle size of 60 nm to obtain two-dimensional polyaramide powder; S3. Weigh 110 mmol of amine curing agent methyltetrahydrophthalic anhydride, add two-dimensional polyaramide powder according to a mass fraction of 0.5%, then put into an ultrasonic water bath to ultrasonically shake and disperse to a homogeneous solution at a power of 300 W, form an amine curing agent containing two-dimensional polyaramide; S4. 50 g of N,N-dimethylformamide solvent, 100 mmol of triethylamine, 110 mmol of melamine were added into a reaction bottle, stirred and mixed uniformly, 110 mmol of perfluorooctanoyl chloride was continuously added dropwise, the addition was completed within 4-6 min, the reaction was continued at 40°C for 13 h, after the reaction was completed, the obtained reaction liquid mixture was centrifuged to separate the solid precipitate, then the precipitate was washed and centrifuged with N,N-dimethylformamide and distilled water until the filtrate was colorless and transparent, then the obtained precipitate was alternately ultrasonically washed and centrifugally separated with dichloromethane and acetone, the obtained solid was placed in a vacuum drying oven at 85°C for drying for 8 h, to obtain perfluorooctanoyl chloride modified melamine; S5. 90 parts by weight of bisphenol A type high viscosity resin E51, 4 parts by weight of perfluorooctanoyl chloride modified melamine, 40 parts by weight of amine curing agent containing two-dimensional polyaramide were added into a reactor, stirred sufficiently, ultrasonically defoamed to obtain a bubble-free pre-crosslinked epoxy resin, cured at 165°C for 11 h to obtain an epoxy resin material based on two-dimensional polyaramide.

[0025] Comparative Example 1 The difference between this comparative example and Example 4 is that no perfluorooctanoyl chloride modified melamine is added.

[0026] Comparative Example 2 The difference between this comparative example and Example 4 is that methyltetrahydrophthalic anhydride is used instead of amine curing agent containing two-dimensional polyaramide.

[0027] Performance test The sample size of the examples and comparative examples is 80 mm x 10 mm x 4 mm; Tensile property test: a universal tensile testing machine was used, and the test was performed in accordance with the GB / T1040-2008 standard, and the tensile rate was 10 mm / min.

[0028] Impact strength test: a simply supported beam impact testing machine was used, and the test was performed in accordance with the ASTM D638-2008 standard, and the sample had no notch.

[0029] Temperature resistance test: a differential scanning calorimeter was used, and the glass transition temperature test was performed under nitrogen environment, and the heating rate was 20°C / min.

[0030] Hydrophobicity test: in accordance with ISO 15989-2004 (Plastics-Determination of contact angle-Drop method), deionized water was added on the surface of the material, and a contact angle measuring instrument was used to measure the static contact angle.

[0031] Table 1: Performance test

[0032] As can be seen from Table 1, the epoxy resin material of the two-dimensional polyaramid prepared by the application has good mechanical properties, temperature resistance and hydrophobic effect. In the comparative example 1, the melamine modified by perfluorooctanoyl chloride is absent, the interfacial bonding force is weakened, the stress transfer efficiency is reduced, the interfacial bonding is weak, the molecular chain is easy to slide at high temperature, the crosslinking network stability is reduced, resulting in the decrease of mechanical properties and temperature resistance; there is no low surface energy group, and the hydrophobic ability is weak due to the low polarity of the epoxy itself. In the comparative example 2, the two-dimensional polyaramid is absent, the “three-dimensional support network” is absent, the microcrack propagation cannot be inhibited, the anti-deformation ability is significantly weakened, there is no “physical barrier layer”, the crosslinking network lacks π-π stacking strengthening, it is easy to relax at high temperature, there is no nanoscale micro-rough surface, the hydrophobic effect cannot be amplified, resulting in the decrease of mechanical properties, temperature resistance and hydrophobic effect.

[0033] It should be noted that in this document, the terms “comprising”, “including”, or any other variant thereof are intended to cover non-exclusive inclusions, so that processes, methods, articles or devices that include a series of elements not only include those elements, but also include other elements not explicitly listed, or include elements inherent to such processes, methods, articles or devices. Without more limitations, the element defined by the statement “comprising a” does not exclude the presence of other identical elements in the process, method, article or device that includes the element.

[0034] The above examples are only used to illustrate the technical solutions of the application, but not to limit it; although the application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the application.

[0035] Those skilled in the art should understand that the above only describes some specific embodiments of the application, rather than all embodiments.

Claims

1. A method for producing a two-dimensional polyaramid-based epoxy resin material, characterized by, Comprising the following steps: S1. Melamine and 1,3,5-benzene tricarbonyl chloride are added to a reaction bottle, then 4-5 mL of pyridine and 40-42 mL of N-methyl pyrrolidone are added in turn, stirring at room temperature for 30-35 h to obtain a crude product, which is washed with anhydrous ethanol, ultrapure water and acetone in turn, ultrasonic for 25-30 min, then centrifuged at 8000-10000 r / min for 4-6 min to separate the solid and liquid phases, and the solid is retained. According to the above process, each solvent is washed 2-3 times, and finally dried at 65-70℃ under vacuum for 15-18 h, cooled to room temperature to obtain a two-dimensional polyaramid; S2. The two-dimensional polyaramid obtained in S1 is ground to a particle size of nanoscale to obtain a two-dimensional polyaramid powder; S3. 100-110 mmol of amine curing agent is weighed, 0.5% of two-dimensional polyaramid powder is added according to the mass fraction, then placed in an ultrasonic water bath to disperse and shock at a power of 280-300 W to form a homogeneous solution, forming an amine curing agent containing two-dimensional polyaramid; S4. 45-50 g of N,N-dimethylformamide solvent, triethylamine, melamine are added to a reaction bottle, stirred and mixed uniformly, and then perfluorooctanoyl chloride is continuously added dropwise, which is completed within 4-6 min, and the reaction is carried out at 36-40℃. After the reaction is completed, the obtained reaction mixture is centrifuged to separate the solid precipitate, which is then washed with N,N-dimethylformamide and distilled water until the filtrate is colorless and transparent, and then the obtained precipitate is alternately ultrasonically washed and centrifugally precipitated and separated, and the obtained solid is placed in a vacuum drying oven at 80-85℃ for 6-8 h to obtain perfluorooctanoyl chloride modified melamine; S5. 80-100 parts by weight of bisphenol A type high viscosity resin E51, 3-5 parts by weight of perfluorooctanoyl chloride modified melamine, and 35-45 parts by weight of amine curing agent containing two-dimensional polyaramid are added to a reactor, stirred thoroughly, and ultrasonically degassed to obtain a bubble-free pre-crosslinked epoxy resin, which is cured to obtain a two-dimensional polyaramid-based epoxy resin material.

2. The method for producing a two-dimensional polyaramid-based epoxy resin material according to claim 1, characterized by, In S1, the mass ratio of melamine to 1,3,5-benzene tricarbonyl chloride is 0.61-0.64 g: 1.31-1.34 g.

3. The method for producing a two-dimensional polyaramid-based epoxy resin material according to claim 1, characterized by, In S2, the particle size is 60-80 nm.

4. The method for producing a two-dimensional polyaramid-based epoxy resin material according to claim 1, characterized by, In S3, the amine curing agent is any one of ethylenediamine, diethylenetriamine, methyltetrahydrophthalic anhydride, and dicyandiamide.

5. The method for producing a two-dimensional polyaramid-based epoxy resin material according to claim 1, characterized by, In S4, the amount ratio of triethylamine, melamine, and perfluorooctanoyl chloride is 80-100 mmol: 80-110 mmol: 80-110 mmol.

6. The method for producing a two-dimensional polyaramid-based epoxy resin material according to claim 1, characterized by, In S4, the reaction time is 10-13 h.

7. The method for producing a two-dimensional polyaramid-based epoxy resin material according to claim 1, characterized by, In S5, the curing temperature is 100-165℃.

8. The method for producing a two-dimensional polyaramid-based epoxy resin material according to claim 1, characterized by, In S5, the curing time is 10-12 h.

9. A two-dimensional polyaramid based epoxy material, characterized in that, Prepared by any one of claims 1-8.

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