Graphene-added furan resin composite and method for preparing the same

Abstract

The application discloses a furan resin composite material added with graphene and a preparation method thereof, and belongs to the technical field of furan resin composite material preparation. The preparation method of the furan resin composite material added with graphene comprises the following steps: step one, furan resin is added into a container, a curing agent is added during stirring, and continuous stirring is carried out to obtain a premixed resin; step two, a modified toughening agent is slowly added into the premixed resin, heating and continuous stirring are carried out to obtain a toughening mixture; step three, modified graphene is added into ethanol, ultrasonic dispersion is carried out, the toughening mixture is slowly dripped, high-speed stirring is carried out to obtain a composite mixture, the composite mixture is subjected to vacuum degassing, and then is added into a mold, solidification is carried out to obtain the furan resin composite material added with graphene. The composite material prepared by the method has excellent heat conductivity, flame retardancy and toughness.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of furan resin composite material, and particularly relates to a graphene-added furan resin composite material and a preparation method thereof. BACKGROUND

[0002] Furan resin, as an important thermosetting resin, has been widely used in the field of corrosion prevention for a long time due to its excellent corrosion resistance, thermal stability, wide raw material sources and simple production process. However, with the progress of science and technology and the continuous improvement of engineering requirements, some performance shortcomings of furan resin have gradually emerged, especially in the aspects of mechanical properties and thermal conductivity. These defects limit the application of furan resin in some high-end fields such as aerospace and precision instrument manufacturing, which have very high requirements for the comprehensive performance of materials. Traditional furan resin cannot meet the requirements of these fields.

[0003] Under this background, graphene is a two-dimensional material composed of single-layer carbon atoms, which has extremely high strength, excellent electrical and thermal conductivity, and unique physical and chemical properties. By adding graphene to furan resin, the excellent properties of graphene can be fully utilized to modify furan resin. On the one hand, the high strength of graphene can improve the mechanical properties of furan resin, such as tensile strength and Young's modulus, so that it can withstand greater external forces without being damaged. On the other hand, the excellent electrical and thermal conductivity of graphene can endow furan resin with new functional characteristics such as electromagnetic shielding and heat conduction, thereby broadening its application field.

[0004] Patent CN110079050A discloses a heat-conducting and flame-retardant epoxy resin composite material and a preparation method thereof. The composite material includes an epoxy resin matrix and a reduced graphene oxide-silver nanowire aerogel coated with molybdenum disulfide. The reduced graphene oxide-silver nanowire aerogel coated with molybdenum disulfide is dispersed in the epoxy resin matrix, and the volume ratio of the epoxy resin matrix material to the reduced graphene oxide-silver nanowire aerogel coated with molybdenum disulfide is 100:1-100:5. Through this method, the thermal conductivity, flame retardancy and mechanical properties of the composite material can be improved. However, the thermal conductivity, flame retardancy and toughness of the composite material prepared by this method still have room for improvement. SUMMARY

[0005] The purpose of the present application is to provide a graphene-added furan resin composite material and a preparation method thereof, which solves the technical problem of poor thermal conductivity, flame retardancy and toughness of the furan resin composite material in the prior art.

[0006] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0007] The application provides a preparation method of a furan resin composite added with graphene, and comprises the following steps:

[0008] Step one: furan resin is added into a container, a curing agent is added during stirring, continuous stirring is performed, and a premixed resin is obtained;

[0009] Step two: a modified toughening agent is slowly added into the premixed resin, heating and continuous stirring are performed, and a toughening mixture is obtained;

[0010] Step three: modified graphene is added into ethanol, is dispersed through ultrasonic, is slowly added dropwise into the toughening mixture, is stirred at high speed, a composite mixture is obtained, the composite mixture is vacuum degassed, then is added into a mold, is cured, and a furan resin composite added with graphene is obtained.

[0011] As preferred, in the step one, the use amount ratio of the furan resin and the curing agent is (100-120) g:(2-2.4) g, the furan resin is composed of one or more of furfuryl alcohol resin, furfural resin and furfural-acetone resin, the viscosity is 200-500 mPa·s, the purity is greater than or equal to 95 %, the curing agent is composed of one or more of p-toluene sulfonic acid, benzene sulfonic acid and phosphoric acid, the stirring speed during stirring is 200-250 rpm, and the continuous stirring time is 10-25 min.

[0012] As preferred, in the step two, the use amount ratio of the modified toughening agent and the premixed resin is (5-8) g:(110-118) g, the heating and continuous stirring temperature is 48-53 ℃, the continuous stirring time is 30-45 min, and the stirring speed is 200-250 rpm.

[0013] As preferred, the preparation method of the modified toughening agent comprises the following steps:

[0014] Q1: under a nitrogen atmosphere, ethyl hydrazinecarboxylate is added into a reaction container containing anhydrous tetrahydrofuran, stirring is performed, hexamethylene diisocyanate is added into anhydrous tetrahydrofuran, after mixing and stirring, the mixture is slowly added dropwise into the reaction container, low-temperature continuous stirring is performed, standing is performed, continuous stirring is performed, washing is performed, vacuum drying is performed, and compound 1 is obtained;

[0015] Q2: compound 1 is added into anhydrous ethanol, stirring is performed to obtain a mixed solution, then anhydrous potassium carbonate is added, heating and reflux stirring are performed, after the reflux is completed, suction filtration is performed, the crude product is dissolved, the pH is adjusted, filtration is performed, washing is performed, vacuum drying is performed, and compound 2 is obtained;

[0016] Q3: nitric acid is added into silica gel, stirring and mixing are performed, washing is performed, vacuum filtration is performed, nitric acid silicon is obtained, the nitric acid silicon and compound 2 are added into a container containing dichloromethane, stirring is performed at room temperature, filtration is performed, anhydrous magnesium sulfate is added into the filtrate for mixing, filtration is performed, washing is performed, rotary evaporation is performed, and compound 3 is obtained.

[0017] Q4: Compound 3 is added to acetonitrile, and the mixture is stirred to obtain solution a, 2,3-diphenylindole is added to acetonitrile, and the mixture is stirred to obtain solution b, then solution a and solution b are mixed, and the mixture is left to stand, vacuum concentration, purification, vacuum drying, to obtain a modified toughening agent.

[0018] In the above process, the synthesis reaction formula of the modified toughening agent is as follows:

[0019]

[0020] The mass spectrometry analysis results of compound 1 are as follows: m / z: 376.21 (100.0%), 377.21 (15.7%), 378.21 (2.7%), 377.20 (2.2%); the mass spectrometry analysis results of compound 2 are as follows: m / z: 284.12 (100.0%), 285.13 (11.2%), 285.12 (2.2%), 286.13 (1.4%); the mass spectrometry analysis results of compound 3 are as follows: m / z: 280.09 (100.0%), 281.10 (11.1%), 281.09 (2.2%), 282.10 (1.4%); and the mass spectrometry analysis results of the modified toughening agent are as follows: m / z: 818.33 (100.0%), 819.34 (54.7%), 820.34 (15.5%), 821.34 (3.4%), 819.33 (3.0%), 820.33 (1.6%).

[0021] Preferably, in Q1, the amount ratio of ethyl hydrazinecarboxylate and hexamethylene diisocyanate is (9.23-10.38) g:(7.89-8.35) g, the low-temperature continuous stirring temperature is 0-1℃, the stirring time is 10-12 min, the standing time is 2-4 min, the continuous stirring time is 120-150 min, and the washing is performed with anhydrous tetrahydrofuran; in Q2, the amount ratio of compound 1, anhydrous ethanol and anhydrous potassium carbonate is (8-12) g:(280-330) mL:(10.2-14.7) g, the stirring time is 20-24 h, the crude product is dissolved in distilled water treated by freezing, 1 mol / L hydrochloric acid is added dropwise at 0-1℃ to adjust pH=1-2, and the washing is performed with ice distilled water.

[0022] As preferred, in the Q3, the ratio of the amount of nitric acid and silica gel is (5-8) mL:(2.8-3.6) g, the volume fraction of nitric acid is 65 vol%, the stirring and mixing time is 15-20 min, the washing is performed with dichloromethane, the ratio of the amount of silicon nitrate, compound 2 and dichloromethane is (1-1.5) g:(0.42-0.58) g:(12-18) mL, the stirring time at room temperature is 120-150 min, the mixing time is 10-15 min, and the washing is performed with dichloromethane; in the Q4, the ratio of the amount of compound 3 and 2,3-diphenylindole is (0.75-0.93) g:(1.61-1.88) g, the standing time is 12-15 h, the eluent used in the purification process is a mixture of ethyl acetate and petroleum ether with a volume ratio of 1:2, and the vacuum drying time is 10-12 h.

[0023] As preferred, in the step three, the ratio of the amount of modified graphene, ethanol and toughening mixture is (3-6) g:(80-100) mL:(110-115) g, the ultrasonic dispersion time is 15-20 min, the dropping rate is 1-2 mL / min, the high-speed stirring speed is 5000-7000 rpm, the vacuum degree of vacuum defoaming is -0.1 to -0.2 MPa, the temperature is 40-45℃, the time is 30-45 min, and the curing process is: first standing at 25℃ for 4 h, then heating to 80℃ at a rate of 2℃ / min, curing for 2 h, then heating to 120℃, curing for 3 h, and finally heating to 160℃, curing for 1 h.

[0024] As preferred, the preparation method of the modified graphene comprises the following steps:

[0025] S1: Eugenol, deionized water and ammonia water are added to a container containing acetone, stirred, and then a saturated aqueous solution of potassium ferricyanide is slowly added dropwise to the container, after the dropwise addition is completed, the reaction is stirred, after the reaction is completed, filtration, acidification, washing, and vacuum drying are performed to obtain intermediate A; 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is heated and melted, then intermediate A is added, the reaction is carried out under nitrogen protection and temperature increase, after the reaction is completed, cooling is performed to obtain intermediate B;

[0026] S2: Intermediate B, 2,6-naphthalenediol, 2,6-dichlorobenzonitrile and potassium carbonate are added to a container, then toluene and N-methylpyrrolidone are sequentially added, after sufficient stirring, heating reaction is performed, after the reaction is completed, cooling and solidification are performed, then soaking, boiling and vacuum drying are performed to obtain intermediate C;

[0027] S3: Intermediate C is added to N-methylpyrrolidone, after stirring and dissolving, graphene is added, and then stirring and curing are performed to obtain modified graphene.

[0028] The synthesis reaction formula of intermediate C in the above process is as follows:

[0029]

[0030] The mass spectrometry analysis result of intermediate A is: m / z: 326.15 (100.0%), 327.16 (22.0%), 328.16 (3.1%); and the mass spectrometry analysis result of intermediate B is: m / z: 758.22 (100.0%), 759.22 (47.9%), 760.23 (11.4%), 761.23 (2.6%), 760.22 (1.6%).

[0031] Preferably, in S1, the amount ratio of eugenol, deionized water, ammonia water, acetone and saturated aqueous potassium ferricyanide solution is (8-12) g:(50-75) mL:(60-75) mL:(100-120) mL:(45-65) mL, the stirring time is 10-15 min, the stirring reaction temperature is 25-28℃, the reaction time is 16-20 h, acidification is performed with 1 mol / L hydrochloric acid, washing is performed with deionized water, the vacuum drying temperature is 50-60℃, and the time is 20-28 h; the amount ratio of 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and intermediate A is (20-23.2) g:(15-17) g, the heating melting temperature is 130-135℃, the temperature rising reaction temperature is 160-165℃, and the reaction time is 8-10 h.

[0032] Preferably, in S2, the amount ratio of intermediate B, 2,6-naphthalenediol, 2,6-dichlorobenzonitrile, potassium carbonate, toluene and N-methylpyrrolidone is (3.329-4.047) g:(0.288-0.4) g:(2.064-3.096) g:(2.291-2.374) g:(20-25) mL:(60-70) mL, the heating reaction temperature is 150-170℃, cooling and solidification are performed by adding to distilled water, soaking is performed by adding to 1 mol / L hydrochloric acid, boiling is performed by adding to distilled water, the vacuum drying temperature is 100-120℃, and the time is 12-15 h; in S3, the amount ratio of intermediate C, N-methylpyrrolidone and graphene is (2-5) g:(20-30) mL:(1-1.6) g, and the solidification process is: 80℃ for 1 h, 100℃ for 1 h, 120℃ for 1 h, 160℃ for 2 h, 200℃ for 2 h, and 230℃ for 2 h.

[0033] The graphene-added furan resin composite material is prepared by the method according to any one of claims 1-10.

[0034] To sum up, by adopting the technical scheme, the application has the beneficial effects of:

[0035] 1. The application first uses hydrazinecarboxylic acid ethyl ester, hexamethylene diisocyanate, anhydrous potassium carbonate, nitric acid and 2,3-diphenylindole as main raw materials to prepare a modified toughening agent, and then uses eugenol, a saturated aqueous solution of potassium ferricyanide, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2,6-naphthalenediol, 2,6-dichlorobenzonitrile and graphene as main raw materials to prepare modified graphene, and the modified toughening agent and the modified graphene are added to the preparation process of furan resin composite material, which can effectively improve the toughness, thermal stability and conductivity of the furan resin composite material.

[0036] 2. The modified toughening agent prepared in the application is added to the preparation process of the composite material, which can effectively improve the toughness of the composite material, the C-N bond introduced in the modified toughening agent can absorb energy when it breaks, prevent stress concentration at the crack tip, delay crack propagation, and a large number of microcracks formed can increase the fracture surface energy, thereby increasing the toughness, the hexamethylene chain contained has high flexibility, which is inserted in the rigid aromatic network of furan resin, reduces the crosslinking point density, improves the activity of molecular chain segments, and improves the toughness of the composite material.

[0037] 3. The modified graphene prepared in the application is added to the preparation process of the composite material, which can effectively improve the toughness, thermal stability and conductivity of the composite material, the modified graphene can form strong interfacial bonding with the resin matrix, the conjugated structure contained can enhance stress transfer, the hydrogen bond action can inhibit interfacial slip and improve toughness; the phosphorus group contained in the modified graphene can also improve the flame retardant performance of the composite material, and the high thermal conductivity of graphene can accelerate heat diffusion, the rigid conjugated network inhibits molecular chain thermal motion, improves thermal stability, and at the same time, the presence of graphene can also endow the composite material with conductivity. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the application will be described below in a clear and complete manner. Obviously, the described embodiments are only a part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the application.

[0039] Embodiment 1: The embodiment discloses a preparation method of a modified toughening agent, comprising the following steps:

[0040] Q1: Under nitrogen atmosphere, 9.85 g of hydrazine ethyl carbonate was added into a reaction vessel containing 60 mL of anhydrous tetrahydrofuran, stirred, 8.57 g of hexamethylene diisocyanate was added into 60 mL of anhydrous tetrahydrofuran, stirred and mixed, then slowly added into the reaction vessel, continuously stirred for 12 min at 0℃, stood for 4 min, and continuously stirred for 120 min, washed with anhydrous tetrahydrofuran, and vacuum dried to obtain compound 1;

[0041] Q2: 10 g of compound 1 was added into 305 mL of anhydrous ethanol, stirred to obtain a mixed solution, then 12.4 g of anhydrous potassium carbonate was added, warmed and refluxed for 24 h, after the refluxing was completed, filtered, the crude product was dissolved in distilled water treated by freezing, 1 mol / L hydrochloric acid was added dropwise at 0℃ to adjust pH = 1.3, filtered, washed with ice distilled water, and vacuum dried to obtain compound 2;

[0042] Q3: 6.5 mL of nitric acid with a volume fraction of 65 vt% was added into 3.2 g of silica gel, stirred and mixed for 20 min, washed with dichloromethane, vacuum filtered to obtain nitric acid silicon, 1.25 g of nitric acid silicon and 0.5 g of compound 2 were added into a container containing 15 mL of dichloromethane, stirred at room temperature for 140 min, filtered, mixed with anhydrous magnesium sulfate in the filtrate for 12 min, filtered, washed with dichloromethane, and rotary evaporated to obtain compound 3;

[0043] Q4: 0.84 g of compound 3 was added into 10 mL of acetonitrile, stirred and mixed to obtain solution a, 1.73 g of 2,3-diphenylindole was added into 12 mL of acetonitrile, stirred and mixed to obtain solution b, then solution a and solution b were mixed, stood for 12 h, vacuum concentrated, purified, the eluent used in the purification process was a mixed solution of ethyl acetate and petroleum ether with a volume ratio of 1:2, and vacuum dried for 12 h to obtain a modified toughening agent.

[0044] The embodiment discloses a preparation method of modified graphene, comprising the following steps:

[0045] S1: 10 g of eugenol, 62.5 mL of deionized water and 67.5 mL of ammonia water were added into a container containing 110 mL of acetone, stirred for 10 min, then 55 mL of potassium ferricyanide saturated aqueous solution was slowly added into the container, stirred at 28℃ for 18 h after the dropping was completed, filtered, acidified with 1 mol / L hydrochloric acid, washed with deionized water, and vacuum dried at 55℃ for 24 h to obtain intermediate A; 21.6 g of 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was heated and melted at 135℃, then 16 g of intermediate A was added, reacted at 165℃ for 10 h under nitrogen protection, and cooled after the reaction was completed to obtain intermediate B;

[0046] S2: 3.613 g of intermediate B, 0.344 g of 2,6-naphthalenediol, 2.535 g of 2,6-dichlorobenzonitrile and 2.331 g of potassium carbonate were added into a container, then 22.5 mL of toluene and 65 mL of N-methylpyrrolidone were added in sequence, after stirring thoroughly, the reaction was heated at 160°C, after the reaction was completed, it was cooled and solidified by adding into distilled water, soaked by adding into 1 mol / L hydrochloric acid, boiled by adding into distilled water, and dried at 100°C under vacuum for 15 h to obtain intermediate C;

[0047] S3: 3.5 g of intermediate C was added into 25 mL of N-methylpyrrolidone, after stirring and dissolving, 1.3 g of graphene was added, and stirring, solidification and curing were continued, the curing process was: 80°C for 1 h, 100°C for 1 h, 120°C for 1 h, 160°C for 2 h, 200°C for 2 h, and 230°C for 2 h, to obtain modified graphene.

[0048] The embodiment discloses a preparation method of a furan resin composite material added with graphene, comprising the following steps:

[0049] Step one: 110 g of furfuryl alcohol resin (viscosity 350 mPa·s, purity ≥95%) was added into a container, 2.2 g of p-toluenesulfonic acid was added during stirring, and stirring was continued at 220 rpm for 20 min to obtain a premixed resin;

[0050] Step two: 6.5 g of modified toughening agent was slowly added into 114 g of the premixed resin, and heating was continued at 50°C with stirring at 250 rpm for 45 min to obtain a toughening mixture;

[0051] Step three: 4.5 g of modified graphene was added into 90 mL of ethanol, ultrasonic dispersion was carried out for 20 min, and then it was added dropwise into 112.5 g of the toughening mixture at a rate of 2 mL / min, high-speed stirring was carried out at 6000 rpm to obtain a composite mixture, the composite mixture was vacuum degassed (-0.2 MPa, 45°C) for 30 min, and then it was added into a mold, and curing was carried out, the curing process was: first standing at 25°C for 4 h, then temperature rising to 80°C at a rate of 2°C / min, curing for 2 h, then temperature rising to 120°C, curing for 3 h, and finally temperature rising to 160°C, curing for 1 h, to obtain a furan resin composite material added with graphene.

[0052] Embodiment 2: The embodiment discloses a preparation method of a modified toughening agent, comprising the following steps:

[0053] Q1: Under nitrogen atmosphere, 9.23 g of hydrazine ethyl carbonate was added into a reaction container containing 60 mL of anhydrous tetrahydrofuran, stirred, 7.89 g of hexamethylene diisocyanate was added into 60 mL of anhydrous tetrahydrofuran, stirred and mixed, then slowly added into the reaction container, continuously stirred for 12 min at 0℃, stood for 4 min, continuously stirred for 120 min, washed with anhydrous tetrahydrofuran, and vacuum dried to obtain compound 1;

[0054] Q2: 8 g of compound 1 was added into 280 mL of anhydrous ethanol, stirred to obtain a mixed solution, then 10.2 g of anhydrous potassium carbonate was added, warmed and refluxed and stirred for 24 h, after the refluxing was completed, filtration was performed, the crude product was dissolved in frozen and distilled water, 1 mol / L hydrochloric acid was added dropwise at 0℃ to adjust pH = 1.3, filtration was performed, washed with ice distilled water, and vacuum dried to obtain compound 2;

[0055] Q3: 5 mL of nitric acid with a volume fraction of 65 vt% was added into 2.8 g of silica gel, stirred and mixed for 20 min, washed with dichloromethane, vacuum filtered to obtain nitric acid silicon, 1 g of nitric acid silicon and 0.42 g of compound 2 were added into a container containing 12 mL of dichloromethane, stirred at room temperature for 140 min, filtered, anhydrous magnesium sulfate was added into the filtrate to mix for 12 min, filtered, washed with dichloromethane, and rotary evaporated to obtain compound 3;

[0056] Q4: 0.75 g of compound 3 was added into 10 mL of acetonitrile, stirred and mixed to obtain solution a, 1.61 g of 2,3-diphenylindole was added into 12 mL of acetonitrile, stirred and mixed to obtain solution b, then solution a and solution b were mixed, stood for 12 h, vacuum concentrated, purified, the eluent used in the purification process was a mixed solution of ethyl acetate and petroleum ether with a volume ratio of 1:2, and vacuum dried for 12 h to obtain a modified toughening agent.

[0057] The embodiment discloses a preparation method of modified graphene, comprising the following steps:

[0058] S1: 8 g of eugenol, 50 mL of deionized water and 60 mL of ammonia water were added into a container containing 120 mL of acetone, stirred for 10 min, then 45 mL of potassium ferricyanide saturated aqueous solution was slowly added into the container, after the dropping was completed, stirred at 28℃ for 18 h, after the reaction was completed, filtration was performed, acidified with 1 mol / L hydrochloric acid, washed with deionized water, and vacuum dried at 55℃ for 24 h to obtain intermediate A; 20 g of 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was heated and melted at 135℃, then 15 g of intermediate A was added, reacted at 165℃ for 10 h under nitrogen protection, after the reaction was completed, cooled to obtain intermediate B;

[0059] S2: 3.329 g of intermediate B, 0.288 g of 2,6-naphthalenediol, 2.064 g of 2,6-dichlorobenzonitrile, and 2.291 g of potassium carbonate were added to a container, followed by 20 mL of toluene and 60 mL of N-methylpyrrolidone, after stirring, the reaction was heated at 160°C, after the reaction was completed, it was cooled and solidified by adding distilled water, soaked in 1 mol / L hydrochloric acid, boiled in distilled water, and dried at 100°C under vacuum for 15 h to obtain intermediate C;

[0060] S3: 2 g of intermediate C was added to 20 mL of N-methylpyrrolidone, after stirring and dissolving, 1 g of graphene was added, and stirring was continued, and the solidification process was as follows: 80°C for 1 h, 100°C for 1 h, 120°C for 1 h, 160°C for 2 h, 200°C for 2 h, and 230°C for 2 h to obtain modified graphene.

[0061] The embodiment discloses a preparation method of a furan resin composite material added with graphene, comprising the following steps:

[0062] Step one: 100 g of furfuryl alcohol resin (viscosity 350 mPa·s, purity ≥95%) was added to a container, 2 g of p-toluenesulfonic acid was added during stirring, and stirring was performed at 220 rpm for 20 min to obtain a premixed resin;

[0063] Step two: 5 g of modified toughening agent was slowly added to 110 g of the premixed resin, heated at 50°C for 45 min while stirring at 250 rpm to obtain a toughening mixture;

[0064] Step three: 3 g of modified graphene was added to 80 mL of ethanol, ultrasonic dispersion was performed for 20 min, and then it was added dropwise to 110 g of the toughening mixture at a rate of 2 mL / min, high-speed stirring was performed at 6000 rpm to obtain a composite mixture, the composite mixture was vacuum degassed (-0.2 MPa, 45°C) for 30 min, and then it was added to a mold, and solidification was performed, the solidification process was as follows: first, standing at 25°C for 4 h, then increasing the temperature to 80°C at a rate of 2°C / min, solidifying for 2 h, then increasing the temperature to 120°C for solidification for 3 h, and finally increasing the temperature to 160°C for solidification for 1 h to obtain the furan resin composite material added with graphene.

[0065] Embodiment 3: The embodiment discloses a preparation method of a modified toughening agent, comprising the following steps:

[0066] Q1: Under nitrogen atmosphere, 10.38 g of hydrazine carboxylic acid ethyl ester was added into a reaction container containing 60 mL of anhydrous tetrahydrofuran, stirred, 8.35 g of hexamethylene diisocyanate was added into 60 mL of anhydrous tetrahydrofuran, stirred and mixed, then slowly added into the reaction container, continuously stirred for 12 min at 0℃, stood for 4 min, continuously stirred for 120 min, washed with anhydrous tetrahydrofuran, vacuum dried to obtain compound 1;

[0067] Q2: 12 g of compound 1 was added into 330 mL of anhydrous ethanol, stirred to obtain a mixed solution, then 14.7 g of anhydrous potassium carbonate was added, warmed and refluxed and stirred for 24 h, after the refluxing was completed, filtration was performed, the crude product was dissolved in distilled water treated by freezing, 1 mol / L hydrochloric acid was added dropwise at 0℃ to adjust pH = 1.3, filtration was performed, washed with ice distilled water, vacuum dried to obtain compound 2;

[0068] Q3: 8 mL of nitric acid with a volume fraction of 65 vt% was added into 3.6 g of silica gel, stirred and mixed for 20 min, washed with dichloromethane, vacuum filtered to obtain nitric acid silicon, 1.5 g of nitric acid silicon and 0.58 g of compound 2 were added into a container containing 18 mL of dichloromethane, stirred at room temperature for 140 min, filtered, anhydrous magnesium sulfate was added into the filtrate to mix for 12 min, filtered, washed with dichloromethane, rotary evaporated to obtain compound 3;

[0069] Q4: 0.93 g of compound 3 was added into 10 mL of acetonitrile, stirred and mixed to obtain solution a, 1.88 g of 2,3-diphenylindole was added into 12 mL of acetonitrile, stirred and mixed to obtain solution b, then solution a and solution b were mixed, stood for 12 h, vacuum concentrated, purified, the eluent used in the purification process was a mixed solution of ethyl acetate and petroleum ether with a volume ratio of 1:2, vacuum dried for 12 h to obtain a modified toughening agent.

[0070] The embodiment discloses a preparation method of modified graphene, comprising the following steps:

[0071] S1: 12 g of eugenol, 75 mL of deionized water and 75 mL of ammonia water were added into a container containing 100 mL of acetone, stirred for 10 min, then 65 mL of potassium ferricyanide saturated aqueous solution was slowly added into the container, after the dropping was completed, stirred at 28℃ for 18 h, after the reaction was completed, filtration was performed, acidified with 1 mol / L hydrochloric acid, washed with deionized water, vacuum dried at 55℃ for 24 h to obtain intermediate A; 23.2 g of 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was heated and melted at 135℃, then 17 g of intermediate A was added, reacted at 165℃ for 10 h under nitrogen protection, after the reaction was completed, cooled to obtain intermediate B;

[0072] S2: 4.047 g of intermediate B, 0.4 g of 2,6-naphthalenediol, 3.096 g of 2,6- dichlorobenzonitrile, and 2.374 g of potassium carbonate were added to a container, followed by 25 mL of toluene and 70 mL of N-methylpyrrolidone, after stirring, the reaction was heated at 160°C, after the reaction was completed, it was cooled and solidified by adding distilled water, soaked in 1 mol / L hydrochloric acid, boiled in distilled water, and dried at 100°C under vacuum for 15 h to obtain intermediate C;

[0073] S3: 5 g of intermediate C was added to 30 mL of N-methylpyrrolidone, after stirring and dissolving, 1.6 g of graphene was added, and stirring was continued, and the solidification process was as follows: 80°C for 1 h, 100°C for 1 h, 120°C for 1 h, 160°C for 2 h, 200°C for 2 h, and 230°C for 2 h to obtain modified graphene.

[0074] The embodiment discloses a preparation method of a furan resin composite material added with graphene, comprising the following steps:

[0075] Step one: 120 g of furfuryl alcohol resin (viscosity 350 mPa·s, purity ≥95%) was added to a container, 2.4 g of p-toluenesulfonic acid was added during stirring, and stirring was performed at 220 rpm for 20 min to obtain a premixed resin;

[0076] Step two: 8 g of modified toughening agent was slowly added to 118 g of premixed resin, heated at 50°C for 45 min while stirring at 250 rpm to obtain a toughening mixture;

[0077] Step three: 6 g of modified graphene was added to 100 mL of ethanol, ultrasonic dispersion was performed for 20 min, and then it was added dropwise to 115 g of the toughening mixture at a rate of 2 mL / min, high-speed stirring was performed at 6000 rpm to obtain a composite mixture, the composite mixture was vacuum degassed (-0.2 MPa, 45°C) for 30 min, and then it was added to a mold, and the solidification process was as follows: first, standing at 25°C for 4 h, then increasing the temperature to 80°C at a rate of 2°C / min, solidifying for 2 h, then increasing the temperature to 120°C for solidification for 3 h, and finally increasing the temperature to 160°C for solidification for 1 h to obtain a furan resin composite material added with graphene.

[0078] Embodiment 4: The embodiment discloses a preparation method of a modified toughening agent, comprising the following steps:

[0079] Q1: Under nitrogen atmosphere, 9.54 g of hydrazine carboxylic acid ethyl ester was added to a reaction vessel containing 60 mL of anhydrous tetrahydrofuran, stirred, 8.23 g of hexamethylene diisocyanate was added to 60 mL of anhydrous tetrahydrofuran, stirred and mixed, then slowly added dropwise to the reaction vessel, continuously stirred at 0°C for 12 min, stood for 4 min, and continuously stirred for 120 min, washed with anhydrous tetrahydrofuran, and vacuum dried to obtain compound 1;

[0080] Q2: 9 g of compound 1 was added to 295 mL of anhydrous ethanol, stirred to obtain a mixed solution, then 11.3 g of anhydrous potassium carbonate was added, warmed and refluxed and stirred for 24 h, after the refluxing was completed, suction filtration was performed, the crude product was dissolved in distilled water treated by freezing, 1 mol / L hydrochloric acid was added dropwise at 0°C to adjust pH = 1.3, filtered, washed with ice distilled water, and vacuum dried to obtain compound 2;

[0081] Q3: 6 mL of nitric acid with a volume fraction of 65 vt% was added to 3 g of silica gel, stirred and mixed for 20 min, washed with dichloromethane, vacuum filtered to obtain nitric acid silicon, 1.1 g of nitric acid silicon and 0.46 g of compound 2 were added to a container containing 14 mL of dichloromethane, stirred at room temperature for 140 min, filtered, mixed with anhydrous magnesium sulfate in the filtrate for 12 min, filtered, washed with dichloromethane, and rotary evaporated to obtain compound 3;

[0082] Q4: 0.81 g of compound 3 was added to 10 mL of acetonitrile, stirred and mixed to obtain solution a, 1.65 g of 2,3-diphenylindole was added to 12 mL of acetonitrile, stirred and mixed to obtain solution b, then solution a and solution b were mixed, stood for 12 h, vacuum concentrated, purified, the eluent used in the purification process was a mixed solution of ethyl acetate and petroleum ether with a volume ratio of 1:2, and vacuum dried for 12 h to obtain a modified toughening agent.

[0083] The embodiment discloses a preparation method of modified graphene, comprising the following steps:

[0084] S1: 9 g of eugenol, 55 mL of deionized water and 62 mL of ammonia water were added to a container containing 105 mL of acetone, stirred for 10 min, then 50 mL of potassium ferricyanide saturated aqueous solution was slowly added dropwise to the container, after the dropwise addition was completed, 28°C stirring reaction was performed for 18 h, after the reaction was completed, filtration was performed, acidification was performed with 1 mol / L hydrochloric acid, washing was performed with deionized water, and vacuum drying was performed at 55°C for 24 h to obtain intermediate A; 20.8 g of 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was heated and melted at 135°C, then 15.5 g of intermediate A was added, and under nitrogen protection, 165°C warming reaction was performed for 10 h, after the reaction was completed, cooling was performed to obtain intermediate B;

[0085] S2: 3.421 g of intermediate B, 0.312 g of 2,6-naphthalenediol, 2.271 g of 2,6-dichlorobenzonitrile and 2.301 g of potassium carbonate were added into a container, then 21 mL of toluene and 62 mL of N-methylpyrrolidone were added in sequence, after stirring thoroughly, the reaction was heated at 160°C, after the reaction was completed, it was cooled and solidified by adding into distilled water, soaked by adding into 1 mol / L hydrochloric acid, boiled by adding into distilled water, and dried at 100°C under vacuum for 15 h to obtain intermediate C;

[0086] S3: 3 g of intermediate C was added into 22 mL of N-methylpyrrolidone, after stirring and dissolving, 1.2 g of graphene was added, and stirring, solidification and curing were continued, the curing process was as follows: 80°C for 1 h, 100°C for 1 h, 120°C for 1 h, 160°C for 2 h, 200°C for 2 h, and 230°C for 2 h, to obtain modified graphene.

[0087] The embodiment discloses a preparation method of a furan resin composite material added with graphene, comprising the following steps:

[0088] Step one: 105 g of furfuryl alcohol resin (viscosity 350 mPa·s, purity ≥95%) was added into a container, 2.1 g of p-toluenesulfonic acid was added during stirring, and stirring was continued at 220 rpm for 20 min to obtain a premixed resin;

[0089] Step two: 6 g of modified toughening agent was slowly added into 112 g of the premixed resin, and heating was continued at 50°C for 45 min while stirring at 250 rpm to obtain a toughening mixture;

[0090] Step three: 4 g of modified graphene was added into 95 mL of ethanol, ultrasonic dispersion was continued for 20 min, and then the mixture was added dropwise into 111 g of the toughening mixture at a rate of 2 mL / min while high-speed stirring was continued at 6000 rpm to obtain a composite mixture, the composite mixture was vacuum degassed (-0.2 MPa, 45°C) for 30 min, and then was added into a mold, and solidification and curing were continued, the curing process was as follows: first, standing at 25°C for 4 h, then, temperature rising at a rate of 2°C / min to 80°C, and curing for 2 h, then, temperature rising to 120°C, and curing for 3 h, finally, temperature rising to 160°C, and curing for 1 h, to obtain the furan resin composite material added with graphene.

[0091] Comparative Example 1: Comparative Example 1 is compared with Example 1, in the process of preparing the furan resin composite material added with graphene, no modified toughening agent is added, and other conditions are unchanged.

[0092] Comparative Example 2: Comparative Example 2 is compared with Example 1, in the process of preparing the furan resin composite material added with graphene, graphene is used instead of modified graphene, and other conditions are unchanged.

[0093] Experimental example: the properties of the graphene-added furan resin composite materials prepared according to examples 1-4 and comparative examples 1-2 were tested, the toughness of the samples was tested according to GB / T 1040.1-2018, the thermal stability of the samples was tested according to GB / T 27761-2011, and the electrical conductivity of the samples was tested according to GB / T 3048.3-2007, and the test results are shown in Table 1:

[0094] Table 1

[0095] Item Tensile strength / MPa Elongation at break / % Mass reduction rate / % Volume resistivity / Ω·cm Example 1 89.6 6.83 16.2 28.4 Example 2 88.4 6.74 16.5 29.8 Example 3 89.1 6.69 16.9 31.5 Example 4 88.6 6.75 17.1 30.6 Comparative Example 1 72.4 4.25 17.2 31.8 Comparative Example 2 73.6 4.68 24.8 2.41 x 10 3 ]]

[0096] From the test results in Table 1, it can be seen that the composite materials prepared according to examples 1-4 have excellent toughness, thermal stability and electrical conductivity. From the comparison between comparative example 1 and examples 1-4, it can be seen that the addition of the modified toughening agent can effectively improve the toughness of the composite material, and the addition of the modified graphene can effectively improve the toughness, thermal stability and electrical conductivity of the material.

[0097] Ageing resistance. From the comparison between comparative example 2 and examples 2-5, it can be seen that the addition of N-n-butyl-2,2,6,6-tetramethyl-4-piperidinamine can effectively improve the ageing resistance of the charging cable.

[0098] The above is only the preferred embodiment of the present application, but the protection scope of the present application is not limited thereto, and any skilled person in the art can make equivalent replacements or changes according to the technical solution and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

[0099] The preferred embodiments of the present application disclosed above are only used to help explain the present application. The preferred embodiments do not describe all the details and do not limit the present application to the specific embodiments. Obviously, many modifications and changes can be made according to the content of the present application. The present application selects and describes these embodiments in order to better explain the principles and practical applications of the present application, so that those skilled in the art can well understand and utilize the present application. The present application is limited by the claims and their entire scope and equivalents.

Claims

1. A method for preparing a furan resin composite material with added graphene, characterized in that, Includes the following steps: Step 1: Add furan resin to a container, add curing agent while stirring, and continue stirring to obtain premixed resin; Step 2: Slowly add the modified toughening agent to the premixed resin, heat and stir continuously to obtain the toughened mixture; Step 3: Add modified graphene to ethanol, disperse it ultrasonically, and then slowly add it dropwise to the toughening mixture. Stir at high speed to obtain a composite mixture. Degas the composite mixture under vacuum, then add it to a mold and cure it to obtain a furan resin composite material with added graphene. The preparation method of the modified toughening agent includes the following steps: Q1: Under a nitrogen atmosphere, ethyl hydrazine carbamate was added to a reaction vessel containing anhydrous tetrahydrofuran and stirred. Hexamethylene diisocyanate was added to anhydrous tetrahydrofuran and stirred to mix. The mixture was then slowly added dropwise to the reaction vessel. The mixture was stirred continuously at low temperature, allowed to stand, stirred again, washed, and dried under vacuum to obtain compound 1. Q2: Add compound 1 to anhydrous ethanol, stir to obtain a mixture, then add anhydrous potassium carbonate, heat to reflux and stir. After reflux, filter, dissolve crude product, adjust pH, filter, wash, and vacuum dry to obtain compound 2. Q3: Add nitric acid to silica gel, stir and mix, wash, and vacuum filter to obtain silicon nitrate. Add silicon nitrate and compound 2 to a container containing dichloromethane, stir at room temperature, filter, add anhydrous magnesium sulfate to the filtrate and mix, filter, wash, and rotary evaporate to obtain compound 3. Q4: Add compound 3 to acetonitrile and stir to obtain solution a. Add 2,3-diphenylindole to acetonitrile and stir to obtain solution b. Then mix solution a and solution b, let stand, concentrate under vacuum, purify, and dry under vacuum to obtain the modified toughening agent. The method for preparing the modified graphene includes the following steps: S1: Eugenol, deionized water, and ammonia were added to a container containing acetone and stirred. Then, a saturated aqueous solution of potassium ferricyanide was slowly added dropwise to the container. After the addition was complete, the mixture was stirred to react. After the reaction was complete, the mixture was filtered, acidified, washed, and dried under vacuum to obtain intermediate A. 10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was heated to melt, and then intermediate A was added. The mixture was heated to react under nitrogen protection. After the reaction was complete, it was cooled to obtain intermediate B. S2: Add intermediate B, 2,6-naphthol, 2,6-dichlorobenzonitrile and potassium carbonate to a container, then add toluene and N-methylpyrrolidone in sequence. After stirring thoroughly, heat to react. After the reaction is complete, cool and solidify, soak, boil, and vacuum dry to obtain intermediate C. S3: Add intermediate C to N-methylpyrrolidone, stir to dissolve, then add graphene, continue stirring, and solidify to obtain modified graphene.

2. The method for preparing the furan resin composite material with added graphene according to claim 1, characterized in that, In step one, the ratio of furan resin to curing agent is (100-120)g:(2-2.4)g, the stirring speed is 200-250rpm, and the stirring time is 10-25min.

3. The method for preparing the furan resin composite material with added graphene according to claim 1, characterized in that, In step two, the ratio of modified toughening agent to premixed resin is (5-8)g:(110-118)g, the heating and stirring temperature is 48-53℃, and the stirring time is 30-45min.

4. The method for preparing the furan resin composite material with added graphene according to claim 1, characterized in that, In Q1, the ratio of ethyl hydrazine carbamate to hexamethylene diisocyanate is (9.23-10.38) g: (7.89-8.35) g; in Q2, the ratio of compound 1, anhydrous ethanol, and anhydrous potassium carbonate is (8-12) g: (280-330) mL: (10.2-14.7) g.

5. The method for preparing the furan resin composite material with added graphene according to claim 1, characterized in that, In Q3, the ratio of nitric acid to silica gel is (5-8) mL: (2.8-3.6) g, and the ratio of silica nitrate, compound 2, and dichloromethane is (1-1.5) g: (0.42-0.58) g: (12-18) mL; in Q4, the ratio of compound 3 to 2,3-diphenylindole is (0.75-0.93) g: (1.61-1.88) g.

6. The method for preparing the furan resin composite material with added graphene according to claim 1, characterized in that, In step three, the ratio of modified graphene, ethanol and toughening mixture is (3-6) g: (80-100) mL: (110-115) g, the dropping rate is 1-2 mL / min, the high-speed stirring speed is 5000-7000 rpm, and the curing process is as follows: first, stand at 25℃ for 4 hours, then heat up to 80℃ at a rate of 2℃ / min and cure for 2 hours, then heat up to 120℃ and cure for 3 hours, and finally heat up to 160℃ and cure for 1 hour.

7. The method for preparing the furan resin composite material with added graphene according to claim 1, characterized in that, In S1, the ratio of eugenol, deionized water, ammonia, acetone and potassium ferricyanide saturated aqueous solution is (8-12) g: (50-75) mL: (60-75) mL: (100-120) mL: (45-65) mL; the ratio of 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and intermediate A is (20-23.2) g: (15-17) g.

8. The method for preparing the furan resin composite material with added graphene according to claim 1, characterized in that, In S2, the ratio of intermediate B, 2,6-naphthol, 2,6-dichlorobenzonitrile, potassium carbonate, toluene, and N-methylpyrrolidone is (3.329-4.047) g : (0.288-0.4) g : (2.064-3.096) g : (2.291-2.374) g : (20-25) mL : (60-70) mL; in S3, the ratio of intermediate C, N-methylpyrrolidone, and graphene is (2-5) g : (20-30) mL : (1-1.6) g.

9. A graphene-added furan resin composite material prepared by the method according to any one of claims 1-8.

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