Preparation method of modified graphene reinforced special epoxy resin

Abstract

The invention discloses a preparation method of modified graphene reinforced special epoxy resin, which comprises the following steps: carrying out substitution reaction on hydroxyl and / or carboxyl in graphene oxide and acyl chloride containing an olefin functional group to prepare modified graphene containing the olefin functional group; the hydrogenated epoxy resin monomer is dehydrated after being dissolved in a solvent, a catalyst and epichlorohydrin are added for an etherification ring-opening reaction, after the reaction is completed, a ring-closing reaction catalyst is added for a ring-closing reaction, and the hydrogenated special epoxy resin is prepared; adding the olefin functional group modified graphene into the hydrogenated special epoxy resin reaction liquid for reaction; and washing with water, neutralizing, filtering and removing the solvent to prepare the special epoxy resin reinforced by modified graphene. The graphene oxide with vinyl functional groups and the reinforced hydrogenated special epoxy resin are adopted to prepare the special epoxy resin with better electric conduction, wave absorption, corrosion resistance, heat dissipation effects and mechanical properties, and the special epoxy resin is applied to harsh working conditions such as marine ship coatings and special electronic packaging.

Description

Technical Field

[0001] The invention belongs to the technical field of special epoxy resin synthesis, and particularly relates to a method for preparing a modified graphene-reinforced special epoxy resin. Background Art

[0002] Epoxy resin is a general term for a class of polymers containing more than two epoxy groups in the molecule. It is an important thermosetting organic polymer material. As one of the three general-purpose resins, epoxy resin is widely used as a coating, insulating packaging material and adhesive in various fields of the national economy, such as construction, aerospace, national defense and military industry, and medical equipment, due to its advantages such as high bonding strength, low shrinkage, good chemical stability and good electrical insulation.

[0003] Epoxy resins are mainly bisphenol A epoxy resins of the glycidyl ether type, which are used in the largest amount, and their production capacity and demand account for more than 90% of the entire epoxy resin. Bisphenol A epoxy resin monomers have a double benzene ring aromatic structure. When used in areas of direct contact with the human body, they will cause reproductive toxicity, carcinogenicity, teratogenicity and other risks to the human body. This unsaturated and rigid double benzene ring structure will also cause the weather resistance and anti-yellowing properties of bisphenol A epoxy resin to weaken and its impact resistance to decrease when exposed to ultraviolet rays. With the continuous expansion of the application field of materials, epoxy resins are used as coatings for wind turbine blades, naval vessel shells, and aircraft shells. They need to be safe, non-toxic, and have good weather resistance. Epoxy resins are used as adhesives for high-frequency electronic packaging materials. They need to have higher bonding properties, better heat transfer and heat dissipation properties, and reduce energy loss during high-frequency electron transmission. In addition to the properties of conventional bisphenol A epoxy resins, the preparation of special epoxy resins that meet specific operating conditions is receiving more and more attention.

[0004] CN 104193961 discloses a method for preparing hydrogenated bisphenol A epoxy resin, wherein the raw materials are pretreated to remove the water content in the epoxy resin monomer and the solvent, the catalytic activity of the Lewis acid catalyst is improved, the raw materials are washed and desalted, and then alkali is added for refining. The crude product is washed, neutralized, filtered, desolventized, and other post-treatments to obtain a hydrogenated bisphenol A epoxy resin with low hydrolysis chlorine and low chroma. CN 115505239 discloses a method for preparing a polysiloxane-modified epoxy resin material. The polysiloxane phase structures of different sizes prepared by the method give the polysiloxane-modified epoxy resin composite material different properties and show good toughness and mechanical strength. CN117700654 discloses a copolyester for weather-resistant coatings and its preparation method and application. By introducing a hydrogenated bisphenol A structure into the copolyester, the hardness of the product is improved, and the heat resistance, weather resistance, scratch resistance and chemical stability are further enhanced. At the same time, the betulin monomer is introduced, and its special structure is utilized to greatly improve the weather resistance of the product. CN 117209721 discloses that bisphenol A epoxy resin is used as raw material and a direct hydrogenation method is adopted to prepare hydrogenated bisphenol A epoxy resin having strong weather resistance and yellowing resistance.

[0005] In summary, the unsaturated double bonds in epoxy resins lead to poor weather resistance and weak yellowing resistance. Hydrogenated bisphenol A epoxy resin can improve its weather resistance and yellowing resistance because it does not contain unsaturated groups in its structure. However, hydrogenated bisphenol A epoxy resin still needs to be further improved in terms of heat resistance, heat dissipation, conductivity, and mechanical properties. Graphene has attracted widespread attention from researchers because of its many advantages given by its own structure. With the significant reduction in the cost of graphene preparation, it is of great significance to introduce it into epoxy resin to improve the performance of the resin. Summary of the invention

[0006] The present invention directly performs vinyl functional group grafting modification on graphene oxide, and further performs adhesive reaction on the graphene oxide containing vinyl functional group modification and hydrogenated epoxy resin, thereby further improving the heat resistance, heat dissipation and electrical conductivity of the epoxy resin, and also greatly improving its mechanical properties. The application of the present invention in the field of national defense and military industry can be further expanded.

[0007] In order to achieve the above-mentioned purpose, the technical solution provided by the present invention is: S1: Under N2 protection conditions, a certain amount of graphene oxide is added to an organic solvent and stirred thoroughly. After being evenly dispersed, a coupling agent is added in a certain proportion, the mixture is heated to the boiling point and refluxed for a certain period of time, centrifuged, washed with solvent, and the solvent is removed to obtain olefin functional group-modified graphene oxide.

[0008] S2: The hydrogenated epoxy resin monomer and the solvent are added into the reactor in a certain proportion, and the hydrogenated epoxy resin monomer and the solvent are first dehydrated. After the dehydration is completed, the catalyst and epichlorohydrin are added, and the mixture is fully stirred under the protection of N2, and the temperature is raised to a certain temperature to carry out the etherification ring-opening reaction.

[0009] S3: After the etherification ring-opening reaction is completed, the temperature is lowered to a certain temperature, and a ring-closing catalyst is added after removing part of the solvent. The mixture is fully stirred under the protection of N2, and the temperature is raised to a certain temperature, and a certain reaction time is maintained for a ring-closing reaction to obtain a hydrogenated epoxy resin.

[0010] S4: Under N2 protection and certain temperature conditions, graphene modified with olefin functional groups is added to the hydrogenated special epoxy resin reaction liquid while stirring to carry out bonding and grafting reactions.

[0011] S5: washing with water, neutralizing, filtering, and removing the solvent under vacuum conditions to obtain a graphene-modified hydrogenated special epoxy resin with olefin functional groups.

[0012] Preferably, in step S1, the graphene oxide has a single layer or multiple layers, and a size of 50 nm-5 μm. The solvent is one or more of tetrahydrofuran, cyclohexane, cyclopentane, and 2-methyltetrahydrofuran.

[0013] Preferably, in step S1, the coupling agent is an acyl chloride compound containing an olefin, and the number of olefin functional groups and acyl chloride functional groups is not limited, and preferably 1-2.

[0014] Preferably, in step S1, the olefin-containing acyl chloride compound is one or more of acryloyl chloride, 1,2-dimethylacryloyl chloride, 3,3-dimethylacryloyl chloride, 2-butenoyl chloride, 4-pentenoyl chloride, oleoyl chloride, and trans-butadiene dichloride.

[0015] Preferably, in step S1, the mass ratio of the graphene oxide to the acyl chloride coupling agent containing olefin functional groups is 1:1-1:100, the reflux temperature is 60-200°C, more preferably, the reflux temperature is 90-150°C, the reflux time is 5-48 h, more preferably, the reflux time is 24-36 h.

[0016] Preferably, in step S2, the epoxy resin monomer is one or more of hydrogenated bisphenol A (2,2-bis(4-hydroxycyclohexyl)propane), hydrogenated bisphenol F (4,4-dihydroxydicyclohexylmethane), 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,5-pentanediol, and 1,6-hexanediol. The solvent is one or more of toluene, xylene, cyclohexane, methyl isobutyl ketone, isophorone, and N,N-dimethylformamide.

[0017] Preferably, in step S2, the catalyst is one or more of boron trifluoride ethyl etherate, tin tetrachloride, butyltin dilaurate, tetrabutyltin, triphenyltin. The reaction temperature is 50-100° C., the molar ratio of epichlorohydrin to hydrogenated epoxy resin monomer is 2-2.3:1, the weight ratio of the catalyst to the hydrogenated epoxy resin monomer is 0.1-0.8%, and the reaction time is 0.5-6.0 h.

[0018] Preferably, in step S3, the temperature is reduced to 5-25°C, and water is added after the temperature is reduced to consume the catalyst to terminate the reaction. The solvent is removed at the boiling point of the solvent under normal pressure or vacuum conditions, and the amount of solvent removed is 30-60% of the amount of the original solvent added, and the closed-loop catalyst is one or more of sodium hydroxide, potassium hydroxide, triethylamine, and tetraethylamine. The ratio of the amount of the catalyst to the molar amount of the hydrogenated epoxy resin monomer is 2.0-2.2:1, the closed-loop reaction temperature is 70-120°C, more preferably, the closed-loop reaction temperature is 90-110°C, and the reaction time is 6-20 h, more preferably, the reaction time is 8-16 h.

[0019] Preferably, in step S4, the mass ratio of graphene oxide with olefin functional groups to hydrogenated epoxy resin is 0.01-0.2:1, the bonding temperature is 70-140° C., and the reaction time is 0.5-5 h.

[0020] Preferably, in step S5, the desolvation is carried out in a N2 atmosphere at a temperature of 120-140°C and a vacuum degree of less than -0.095 MPa, and after the solvent is removed, N2 is used to restore the atmospheric pressure.

[0021] The prepared modified graphene-enhanced special epoxy resin can be directly used alone as a paint thinner, or can be used in combination with other curing agents and fillers according to the requirements of working conditions.

[0022] The advantages of the present invention compared with the prior art are: 1. There are many methods for modifying epoxy resin by direct physical mixing. The present invention uses a coupling agent to modify graphene oxide to prepare graphene oxide modified with vinyl functional groups.

[0023] 2. Different from ordinary bisphenol A epoxy resin, the special epoxy resin monomer selected in the present invention does not contain unsaturated double bonds in its molecular structure, and the prepared hydrogenated special epoxy resin itself has the characteristics of corrosion resistance, oxidation resistance, impact resistance and good fluidity.

[0024] 3. The present invention utilizes vinyl functional groups to react with special epoxy resins for adhesive reaction, and uses a chemical reaction grafting method to modify the special epoxy resins with graphene, thereby improving the heat resistance, heat dissipation, and electrical conductivity of the epoxy resins, and also improving their mechanical properties to a great extent. Its application in the field of national defense and military industry can be further expanded. DETAILED DESCRIPTION

[0025] The present invention is further described below through examples and comparative examples, and the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0027] Example 1 S1: Add 5g of graphene oxide and 50g of acryloyl chloride into a three-necked flask replaced with N2, add 500mL of tetrahydrofuran under N2 protection and stir to fully dissolve and disperse it, heat to 65℃ and reflux for 16 hours. After the reaction is completed, stop stirring, let it stand and settle naturally, and take out the upper clear liquid. Centrifuge to separate the solvent in the product, wash it with 100mL of tetrahydrofuran and centrifuge it, repeat the operation 5 times, and vacuum dry to obtain the vinyl-modified graphene oxide product.

[0028] S2: Under the protection of N2, add 100 g hydrogenated bisphenol A and 110 g solvent toluene into a three-necked flask, stir and dissolve evenly, then heat to 113°C for reflux dehydration. After anhydrous water is generated in the water separator, slowly cool to 100-102°C, add 0.3 g catalyst boron trifluoride ether, stir evenly, then slowly drop 87 g epichlorohydrin, the drop rate is 0.5 g / min, the reaction temperature is controlled at 98-105°C during the drop process, and after the drop of epichlorohydrin is completed, cool to 90°C and continue to react for 1 h.

[0029] S3: After the etherification ring-opening reaction is completed, 55g of toluene solvent is recovered, 110g of clean water is added, and 88g of 50% NaOH solution is slowly added dropwise. The addition time is controlled at 2-2.5 h, and the reaction temperature is controlled at 90 ℃. After the NaOH solution is completely added, the reaction is continued for 10h. After the reaction is completed, 110g of toluene solvent is added, stirring is stopped after uniform stirring, and the lower aqueous phase is removed, H3PO4 is added to adjust the pH ≤ 6, and water washing is repeated for more than 3 times. After water washing, it is filtered and vacuum dehydrated to remove the solvent, and the vacuum degree is less than -0.09MPa, and the temperature is 90-155℃. 152.3g of colorless, transparent, viscous liquid product is obtained.

[0030] S4: N2 protection, add 400 mL of dehydrated toluene solvent into a three-necked flask, add 2 g of graphene oxide modified with acryloyl chloride in S1, stir and disperse evenly, raise the temperature to 90-105°C, slowly add 98 g of hydrogenated bisphenol A glycidyl ether in S3, add for 2 h, and continue the reaction for 6 h after addition.

[0031] S5: After the reaction of S4 is completed, the mixture is allowed to stand for stratification, the upper clear liquid is removed, the lower liquid is centrifuged to remove the solvent, and 200 mL of toluene solvent is used for washing each time, and centrifugation is performed after washing, and this process is repeated 3 times. After vacuum drying, 99.1 g of hydrogenated bisphenol A epoxy resin modified with vinyl functional group graphene is obtained.

[0032] Example 2 Steps S1, S2 and S3 in Example 2 are the same as those in Example 1.

[0033] S4: Under N2 protection, add 800 mL of dehydrated toluene solvent into a three-necked flask, add 5 g of graphene oxide modified with acryloyl chloride in S1, stir and disperse evenly, raise the temperature to 90-105°C, slowly add 95 g of hydrogenated bisphenol A glycidyl ether in S3, add for 2 h, and continue the reaction for 6 h after addition.

[0034] S5: After the reaction of S4 is completed, the mixture is allowed to stand for stratification, the upper clear liquid is removed, the lower liquid is centrifuged to remove the solvent, and 200 mL of toluene solvent is used for washing each time, and centrifugation is performed after washing, and this process is repeated 3 times. After vacuum drying, 99.2 g of hydrogenated bisphenol A epoxy resin modified with vinyl functional group graphene is obtained.

[0035] Example 3 Steps S1, S2 and S3 in Example 3 are the same as those in Example 1.

[0036] S4: N2 protection, add 1200 mL of dehydrated toluene solvent into a three-necked flask, add 10 g of graphene oxide modified with acryloyl chloride in S1, stir and disperse evenly, raise the temperature to 90-105°C, slowly add 90 g of hydrogenated bisphenol A glycidyl ether in S3, add for 2 h, and continue the reaction for 6 h after addition.

[0037] S5: After the reaction of S4 is completed, the mixture is allowed to stand for stratification, the upper clear liquid is removed, the lower liquid is centrifuged to remove the solvent, and 200 mL of toluene solvent is used for washing each time, and centrifugation is performed after washing, and this process is repeated 3 times. After vacuum drying, 99.0 g of hydrogenated bisphenol A epoxy resin modified with vinyl functional group graphene is obtained.

[0038] Example 4 S1: Add 5 g of graphene oxide and 50 g of 3,3-dimethylacryloyl chloride into a three-necked flask replaced with N2, add 500 mL of toluene under N2 protection and stir to fully dissolve and disperse it, heat to 113 °C and reflux for 16 h. After the reaction is completed, stop stirring, let it stand and settle naturally, and take out the upper clear liquid. Centrifuge to separate the solvent in the product, wash it with 100 mL of tetrahydrofuran and centrifuge it, repeat the operation 5 times, and vacuum dry to obtain the vinyl-modified graphene oxide product.

[0039] S2: Under the protection of N2, add 100 g of 1,4-cyclohexanedimethanol and 110 g of solvent toluene into a three-necked flask, stir and dissolve evenly, then heat to 113°C for reflux dehydration. After anhydrous water is generated in the water separator, slowly cool to 100-102°C, add 0.3 g of catalyst butyltin dilaurate, stir evenly, then slowly drop 87 g of epichlorohydrin, the drop rate is 0.5 g / min, the reaction temperature is controlled at 98-105°C during the drop process, and after the drop of epichlorohydrin is completed, cool to 90°C and continue to react for 1 h.

[0040] S3: After the etherification ring-opening reaction is completed, 55 g of toluene solvent is recovered, 110 g of clean water is added, and 88 g of 50% NaOH solution is slowly added dropwise. The addition time is controlled at 2-2.5 h, and the reaction temperature is controlled at 90 °C. After the NaOH solution is completely added, the reaction is continued for 10 h. After the reaction is completed, 110 g of toluene solvent is added, stirring is stopped after uniform stirring, and the lower aqueous phase is removed, H3PO4 is added to adjust the pH to ≤ 6, and water washing is repeated for more than 3 times. After water washing, it is filtered and vacuum dehydrated to remove the solvent, and the vacuum degree is less than -0.09MPa, and the temperature is 90-155 °C. 151.2 g of colorless, transparent, viscous liquid product is obtained.

[0041] S4: N2 protection, add 400 mL of dehydrated toluene solvent into a three-necked flask, add 2 g of graphene oxide modified with 3,3-dimethylacryloyl chloride in S1, stir and disperse evenly, raise the temperature to 90-105°C, slowly add 98 g of hydrogenated bisphenol A glycidyl ether in S3, add for 2 h, and continue the reaction for 6 h after addition.

[0042] S5: After the reaction of S4 is completed, the mixture is allowed to stand for stratification, the upper clear liquid is removed, the lower liquid is centrifuged to remove the solvent, and 200 mL of toluene solvent is used for washing each time, and centrifugation is performed after washing, and this process is repeated 3 times. After vacuum drying, 99.2 g of hydrogenated bisphenol A epoxy resin modified with vinyl functional group graphene is obtained.

[0043] Example 5 Steps S1, S2 and S3 in Example 5 are the same as those in Example 4.

[0044] S4: Under N2 protection, add 800 mL of dehydrated toluene solvent into a three-necked flask, add 5 g of graphene oxide modified with 3,3-dimethylacryloyl chloride in S1, stir and disperse evenly, raise the temperature to 90-105°C, slowly add 95 g of hydrogenated bisphenol A glycidyl ether in S3, add for 2 h, and continue the reaction for 6 h after addition.

[0045] S5: After the reaction of S4 is completed, the mixture is allowed to stand for stratification, the upper clear liquid is removed, the lower liquid is centrifuged to remove the solvent, and 200 mL of toluene solvent is used for washing each time, and centrifugation is performed after washing, and this process is repeated 3 times. After vacuum drying, 99.0 g of hydrogenated bisphenol A epoxy resin modified with vinyl functional group graphene is obtained.

[0046] Example 6 Steps S1, S2 and S3 in Example 6 are the same as those in Example 4.

[0047] S4: Under N2 protection, add 1200 mL of dehydrated toluene solvent into a three-necked flask, add 10 g of graphene oxide modified with 3,3-dimethylacryloyl chloride in S1, stir and disperse evenly, raise the temperature to 90-105°C, slowly add 90 g of hydrogenated bisphenol A glycidyl ether in S3, add for 2 h, and continue the reaction for 6 h after addition.

[0048] S5: After the reaction of S4 is completed, the mixture is allowed to stand for stratification, the upper clear liquid is removed, the lower liquid is centrifuged to remove the solvent, and 200 mL of toluene solvent is used for washing each time, and centrifugation is performed after washing, and this process is repeated 3 times. After vacuum drying, 98.7 g of hydrogenated bisphenol A epoxy resin modified with vinyl functional group graphene is obtained.

[0049] Example 7 S1: Add 5 g of graphene oxide and 50 g of 2-butenoyl chloride into a three-necked flask replaced with N2, add 500 mL of toluene under N2 protection and stir to fully dissolve and disperse it, heat to 113 °C and reflux for 16 h. After the reaction is completed, stop stirring, let it stand and settle naturally, and take out the upper clear liquid. Centrifuge to separate the solvent in the product, wash it with 100 mL of tetrahydrofuran and centrifuge it, repeat the operation 5 times, and vacuum dry to obtain the vinyl-modified graphene oxide product.

[0050] S2: Under the protection of N2, add 100 g of 1,5-pentanediol and 110 g of solvent toluene into a three-necked flask, stir and dissolve evenly, then heat to 113°C for reflux dehydration. After anhydrous water is generated in the water separator, slowly cool to 100-102°C, add 0.3 g of catalyst tetrabutyltin, stir evenly, then slowly drop 87 g of epichlorohydrin, the drop rate is 0.5 g / min, and the reaction temperature is controlled at 98-105°C during the drop process. After the drop of epichlorohydrin is completed, cool to 90°C and continue to react for 1 h.

[0051] S3: After the etherification ring-opening reaction is completed, 55 g of toluene solvent is recovered, 110 g of clean water is added, and 88 g of 50% NaOH solution is slowly added dropwise. The addition time is controlled at 2-2.5 h, and the reaction temperature is controlled at 90°C. After the NaOH solution is completely added, the reaction is continued for 10 h. After the reaction is completed, 110 g of toluene solvent is added, stirring is stopped after uniform stirring, and the lower aqueous phase is removed, H3PO4 is added to adjust the pH to ≤ 6, and water washing is repeated for more than 3 times. After water washing, it is filtered and vacuum dehydrated to remove the solvent, and the vacuum degree is less than -0.09MPa, and the temperature is 90-155°C. 151.2 g of colorless, transparent, viscous liquid product is obtained.

[0052] S4: N2 protection, add 400 mL of dehydrated toluene solvent into a three-necked flask, add 2 g of graphene oxide modified with 2-butenoyl chloride in S1, stir and disperse evenly, raise the temperature to 90-105 °C, slowly add 98 g of hydrogenated bisphenol A glycidyl ether in S3, add for 2 h, and continue the reaction for 6 h after addition.

[0053] S5: After the reaction of S4 is completed, the mixture is allowed to stand for stratification, the upper clear liquid is removed, the lower liquid is centrifuged to remove the solvent, and 200 mL of toluene solvent is used for washing each time, and centrifugation is performed after washing, and this process is repeated 3 times. After vacuum drying, 99.1 g of hydrogenated bisphenol A epoxy resin modified with vinyl functional group graphene is obtained.

[0054] Example 8 Steps S1, S2 and S3 in Example 8 are the same as those in Example 4.

[0055] S4: N2 protection, add 800 mL of dehydrated toluene solvent into a three-necked flask, add 5 g of graphene oxide modified with 2-butenoyl chloride in S1, stir and disperse evenly, raise the temperature to 90-105°C, slowly add 95 g of hydrogenated bisphenol A glycidyl ether in S3, add for 2 h, and continue the reaction for 6 h after addition.

[0056] S5: After the reaction of S4 is completed, the mixture is allowed to stand for stratification, the upper clear liquid is removed, the lower liquid is centrifuged to remove the solvent, and 200 mL of toluene solvent is used for washing each time, and centrifugation is performed after washing, and this process is repeated 3 times. After vacuum drying, 99.1 g of hydrogenated bisphenol A epoxy resin modified with vinyl functional group graphene is obtained.

[0057] Example 9 Steps S1, S2 and S3 in Example 9 are the same as those in Example 4.

[0058] S4: N2 protection, add 1200 mL of dehydrated toluene solvent into a three-necked flask, add 10 g of graphene oxide modified with 2-butenoyl chloride in S1, stir and disperse evenly, raise the temperature to 90-105°C, slowly add 90 g of hydrogenated bisphenol A glycidyl ether in S3, add for 2 h, and continue the reaction for 6 h after addition.

[0059] S5: After the reaction of S4 is completed, the mixture is allowed to stand for stratification, the upper clear liquid is removed, the lower liquid is centrifuged to remove the solvent, and 200 mL of toluene solvent is used for washing each time, and centrifugation is performed after washing, and this process is repeated 3 times. After vacuum drying, 98.8 g of hydrogenated bisphenol A epoxy resin modified with vinyl functional group graphene is obtained.

[0060] Comparative Example 1 Under the protection of N2, 100 g of hydrogenated bisphenol A and 110 g of solvent toluene were added to a three-necked flask, stirred and dissolved evenly, and then heated to 113°C for reflux dehydration. After anhydrous water was generated in the water separator, the temperature was slowly lowered to 100-102°C, 0.3 g of catalyst boron trifluoride ether was added, and after stirring evenly, 87 g of epichlorohydrin was slowly added dropwise at a rate of 0.5 g / min. The reaction temperature was controlled at 98-105°C during the addition process. After the epichlorohydrin was added dropwise, the temperature was lowered to 90°C and the reaction was continued for 1 h.

[0061] After the etherification ring-opening reaction is completed, 55 g of toluene solvent is recovered, 110 g of clean water is added, and 88 g of 50% NaOH solution is slowly added dropwise. The addition time is controlled at 2-2.5 h, and the reaction temperature is controlled at 90 ° C. After the NaOH solution is completely added, the reaction is continued for 10 h. After the reaction is completed, 110 g of toluene solvent is added, stirring is stopped after uniform stirring, and stratification is allowed to stand. The lower aqueous phase is removed, H3PO4 is added to adjust the pH ≤ 6, and water washing is repeated for more than 3 times. After water washing, it is filtered and vacuum dehydrated to remove the solvent, and the vacuum degree is less than -0.09 MPa, and the temperature is 90-155 ° C. 152.3 g of colorless, transparent, viscous liquid product is obtained.

[0062] Comparative Example 2 Under N2 protection, 100 g of 1,4-cyclohexanedimethanol and 110 g of solvent toluene were added to a three-necked flask, stirred and dissolved evenly, and then heated to 113°C for reflux dehydration. After anhydrous water was generated in the water separator, the temperature was slowly lowered to 100-102°C, 0.3 g of catalyst butyltin dilaurate was added, and after stirring evenly, 87 g of epichlorohydrin was slowly added dropwise at a rate of 0.5 g / min. The reaction temperature was controlled at 98-105°C during the addition process. After the epichlorohydrin was added dropwise, the temperature was lowered to 90°C and the reaction was continued for 1 h.

[0063] After the etherification ring-opening reaction is completed, 55 g of toluene solvent is recovered, 110 g of clean water is added, and 88 g of 50% NaOH solution is slowly added dropwise. The addition time is controlled at 2-2.5 h, and the reaction temperature is controlled at 90°C. After the NaOH solution is completely added, the reaction is continued for 10 h. After the reaction is completed, 110 g of toluene solvent is added, stirring is stopped after uniform stirring, and the lower aqueous phase is removed, H3PO4 is added to adjust the pH to ≤ 6, and water washing is repeated for more than 3 times. After water washing, filtering is performed, and vacuum dehydration is performed to remove the solvent, and the vacuum degree is less than -0.09 MPa, and the temperature is 90-155°C. 151.2 g of colorless, transparent, viscous liquid product is obtained.

[0064] Comparative Example 3 Under N2 protection, 100 g of 1,5-pentanediol and 110 g of solvent toluene were added to a three-necked flask, stirred and dissolved evenly, and then heated to 113°C for reflux dehydration. After anhydrous water was generated in the water separator, the temperature was slowly lowered to 100-102°C, 0.3 g of catalyst tetrabutyltin was added, and after stirring evenly, 87 g of epichlorohydrin was slowly added dropwise at a rate of 0.5 g / min. The reaction temperature was controlled at 98-105°C during the addition process. After the epichlorohydrin was added dropwise, the temperature was lowered to 90°C and the reaction was continued for 1 h.

[0065] After the etherification ring-opening reaction is completed, 55 g of toluene solvent is recovered, 110 g of clean water is added, and 88 g of 50% NaOH solution is slowly added dropwise. The addition time is controlled at 2-2.5 h, and the reaction temperature is controlled at 90 °C. After the NaOH solution is completely added, the reaction is continued for 10 h. After the reaction is completed, 110 g of toluene solvent is added, stirring is stopped after uniform stirring, and the lower aqueous phase is removed, H3PO4 is added to adjust the pH ≤ 6, and water washing is repeated for more than 3 times. After water washing, it is filtered and vacuum dehydrated to remove the solvent, and the vacuum degree is less than -0.09 MPa and the temperature is 90-155 °C. 151.2 g of colorless, transparent, viscous liquid product is obtained.

[0066] Comparative Example 4 Under N2 protection, 100 g of bisphenol A and 110 g of solvent toluene were added to a three-necked flask, stirred and dissolved evenly, and then heated to 113°C for reflux dehydration. After anhydrous water was generated in the water separator, the temperature was slowly lowered to 100-102°C, 0.3 g of catalyst tetrabutyltin was added, and 87 g of epichlorohydrin was slowly added dropwise after stirring evenly, with a drop rate of 0.5 g / min. The reaction temperature was controlled at 98-105°C during the dropwise addition process. After the dropwise addition of epichlorohydrin was completed, the temperature was lowered to 90°C and the reaction was continued for 1 h.

[0067] After the etherification ring-opening reaction is completed, 55 g of toluene solvent is recovered, 110 g of clean water is added, and 88 g of 50% NaOH solution is slowly added dropwise. The addition time is controlled at 2-2.5 h, and the reaction temperature is controlled at 90°C. After the NaOH solution is completely added, the reaction is continued for 10 h. After the reaction is completed, 110 g of toluene solvent is added, stirring is stopped after uniform stirring, and the lower aqueous phase is removed, H3PO4 is added to adjust the pH to ≤ 6, and water washing is repeated for more than 3 times. After water washing, filtering is performed, and vacuum dehydration is performed to remove the solvent, and the vacuum degree is less than -0.09 MPa, and the temperature is 90-155°C. 153.2 g of colorless, transparent, viscous liquid product is obtained.

[0068] The performance improvement of the special epoxy resin enhanced by modified graphene in the present invention includes but is not limited to the typical effects detected in the examples, and other beneficial effects not detected also belong to the scope of the claims. The typical effects obtained in the examples are shown in the following table.

[0069] Table 1 Typical effect parameters corresponding to the embodiments The modified graphene is uniformly combined with the epoxy resin through the reaction of vinyl with different epoxy resin monomers (hydrogenated bisphenol A, 1,4-cyclohexanedimethanol, 1,5-pentanediol). The prepared enhanced special epoxy resin has greatly improved thermal conductivity and impact resistance. In addition, due to the introduction of modified graphite oxide, the electrochemical properties of the resin are further enhanced, the breakdown voltage is increased, and the arc resistance time is extended. The three selected epoxy resin monomers have different physical and electrochemical properties of the epoxy resins themselves, but because the conductive and heat transfer effects of graphene oxide are more prominent, the thermal conductivity of the modified enhanced special epoxy resin is significantly improved, and the dielectric loss is greatly reduced, which has broad application prospects in the field of high-end electronic applications.

[0070] The present invention aims to modify hydrogenated special epoxy resin by modified graphene. The specific method is mainly to graft graphene oxide with vinyl functional groups to form graphene oxide with vinyl bridges, and the vinyl double bonds are chemically added with hydrogenated special epoxy resins. The vinyl modified graphene can react with epoxy resin completely and evenly. Due to the difficulty of uniform dispersion of conventional physical and mechanical mixed graphene, the analysis and sampling are accidental, and the physical and chemical properties of the resin modified by graphene oxide alone are not tested. The above embodiments of the present invention have been described, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Without departing from the scope and spirit of the described embodiments, many modifications and changes are obvious to those of ordinary skill in the art. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A method for preparing a modified graphene-enhanced special epoxy resin, characterized in that: The method comprises the following steps: S1: Under N2 protection conditions, a certain amount of graphene oxide is added to an organic solvent and stirred thoroughly. After being evenly dispersed, a coupling agent is added in a certain proportion, the mixture is heated to the boiling point and refluxed for a certain period of time, centrifuged, washed with solvent, and the solvent is removed to obtain olefin functional group-modified graphene oxide; S2: hydrogenated epoxy resin monomer and solvent are added to the reactor in a certain proportion, and the hydrogenated epoxy resin monomer and solvent are first dehydrated. After the dehydration is completed, a catalyst and epichlorohydrin are added, and the mixture is fully stirred under the protection of N2, and the temperature is raised to a certain temperature to carry out an etherification ring-opening reaction; S3: After the etherification ring-opening reaction is completed, the temperature is lowered to a certain temperature, a ring-closing catalyst is added after removing part of the solvent, and the mixture is fully stirred under the protection of N2, the temperature is raised to a certain temperature, and a certain reaction time is maintained for a ring-closing reaction to obtain a hydrogenated epoxy resin; S4: Under N2 protection and certain temperature conditions, graphene modified with olefin functional groups is added to the hydrogenated special epoxy resin reaction liquid while stirring to perform bonding and grafting reactions; S5: washing with water, neutralizing, filtering, and removing the solvent under vacuum conditions to obtain a graphene-modified hydrogenated special epoxy resin with olefin functional groups.

2. The method for preparing the modified graphene-enhanced special epoxy resin according to claim 1, characterized in that In step S1, the graphene oxide has a single layer or multiple layers, and a size of 50 nm-5 μm; the solvent is one or more of tetrahydrofuran, cyclohexane, cyclopentane, and 2-methyltetrahydrofuran.

3. The method for preparing the modified graphene-enhanced special epoxy resin according to claim 1, characterized in that In step S1, the coupling agent is an acyl chloride compound containing an olefin, the number of olefin functional groups and acyl chloride functional groups is not limited, and both are preferably 1-2. The acyl chloride compound containing an olefin is one or more of acyl chloride, 1,2-dimethylacryloyl chloride, 3,3-dimethylacryloyl chloride, 2-butenoyl chloride, 4-pentenoyl chloride, oleoyl chloride, and trans-butadiene dichloride.

4. The method for preparing the modified graphene-enhanced special epoxy resin according to claim 1, characterized in that In step S1, the mass ratio of the graphene oxide to the acyl chloride coupling agent containing an olefin functional group is 1:1-1:100, the reflux temperature is 60-200° C., and the reflux time is 5-48 h.

5. The method for preparing the modified graphene-enhanced special epoxy resin according to claim 1, characterized in that In step S2, the epoxy resin monomer is one or more of hydrogenated bisphenol A (2,2-bis(4-hydroxycyclohexyl)propane), hydrogenated bisphenol F (4,4-dihydroxydicyclohexylmethane), 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,5-pentanediol, and 1,6-hexanediol; and the solvent is one or more of toluene, xylene, cyclohexane, methyl isobutyl ketone, isophorone, and N,N-dimethylformamide.

6. The method for preparing the modified graphene-enhanced special epoxy resin according to claim 1, characterized in that In step S2, the catalyst is one or more of boron trifluoride ethyl ether, tin tetrachloride, butyltin dilaurate, tetrabutyltin, and triphenyltin; the reaction temperature is 50-100°C, the molar ratio of epichlorohydrin to hydrogenated epoxy resin monomer is 2-2.3:1, the weight ratio of the catalyst dosage to the hydrogenated epoxy resin monomer is 0.1-0.8%, and the reaction time is 0.5-2.0h.

7. The method for preparing the modified graphene-enhanced special epoxy resin according to claim 1, characterized in that In step S3, the temperature is reduced to 5-25°C, and water is added after the temperature is reduced to consume the catalyst to terminate the reaction; the solvent is removed at the boiling point of the solvent under normal pressure or vacuum conditions, and the amount of solvent removed is 30-60% of the amount of the original solvent added; the closed-loop catalyst is one or more of sodium hydroxide, potassium hydroxide, triethylamine, and tetraethylamine; the ratio of the amount of the catalyst to the molar amount of the hydrogenated epoxy resin monomer is 2.0-2.2:1, the closed-loop reaction temperature is 70-120°C, and the reaction time is 6-20h.

8. The method for preparing the modified graphene-enhanced special epoxy resin according to claim 1, characterized in that In step S4, the mass ratio of olefin-functionalized graphene oxide to hydrogenated epoxy resin is 0.01-0.2:1, the bonding temperature is 70-140° C., and the reaction time is 0.5-5 h.

9. The method for preparing the modified graphene-enhanced special epoxy resin according to claim 1, characterized in that In step S5, the desolventizing is carried out in a N2 atmosphere at a temperature of 120-140°C and a vacuum degree of less than -0.095 MPa. After the solvent is removed, N2 is used to restore the normal pressure.

10. The use of any modified graphene-enhanced special epoxy resin according to any one of claims 1 to 9, characterized in that The prepared modified graphene-enhanced special epoxy resin can be directly used alone as a paint thinner, or can be used in combination with other curing agents and fillers according to the requirements of working conditions.

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