Furan resin composite material added with graphene and preparation method thereof

Abstract

The invention discloses a graphene-added furan resin composite material and a preparation method thereof, and belongs to the technical field of preparation of furan resin composite materials. The preparation method of the graphene-added furan resin composite material comprises the following steps: step 1, adding furan resin into a container, adding a curing agent in the stirring process, and continuously stirring to obtain premixed resin; step 2, slowly adding the modified flexibilizer into the premixed resin, heating and continuously stirring to obtain a toughened mixture; and 3, adding the modified graphene into ethanol, carrying out ultrasonic dispersion, slowly dropwise adding into the toughening mixture, carrying out high-speed stirring to obtain a composite mixture, carrying out vacuum defoaming on the composite mixture, adding into a mold, and curing to obtain the furan resin composite material added with graphene. The composite material prepared by the method has excellent thermal conductivity, flame retardance and toughness.

Description

Technical Field

[0001] The present invention belongs to the technical field of the preparation of furan resin composites, and particularly relates to a furan resin composite added with graphene and a preparation method thereof. Background Art

[0002] As an important thermosetting resin, furan resin has been widely used in the field of anti-corrosion 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 technology and the continuous improvement of engineering requirements, some performance shortboards of furan resin have gradually emerged, especially the obvious deficiencies in mechanical properties, thermal conductivity, etc. These defects limit the application of furan resin in some high-end fields, such as aerospace and precision instrument manufacturing, which have extremely high requirements for the comprehensive performance of materials, and traditional furan resin is difficult to meet their needs.

[0003] In this context, graphene is a two-dimensional material composed of a single layer of carbon atoms, with extremely high strength, excellent electrical and thermal conductivity, and unique physical and chemical properties. Adding graphene to furan resin can make full use of the excellent properties of graphene 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, enabling it to withstand greater external forces without damage. 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 fields.

[0004] Patent CN110079050A discloses a thermally conductive 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. Among them, 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, but there is still room for improvement in the thermal conductivity, flame retardancy, and toughness of the composite material prepared by this method. Summary of the Invention

[0005] The purpose of the present invention is to provide a furan resin composite added with graphene and a preparation method thereof, which are used to solve the technical problems of poor thermal conductivity, flame retardancy, and toughness of furan resin composites in the prior art.

[0006] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0007] The present invention provides a preparation method of a furan resin composite material added with graphene, comprising the following steps:

[0008] Step 1: Add furan resin into a container, add a curing agent during stirring, and continuously stir to obtain a premixed resin;

[0009] Step 2: Slowly add a modified toughening agent into the premixed resin, heat and continuously stir to obtain a toughened mixture;

[0010] Step 3: Add modified graphene into ethanol, after ultrasonic dispersion, slowly drop it into the toughened mixture, stir at high speed to obtain a composite mixture, carry out vacuum degassing on the composite mixture, then add it into a mold and cure to obtain a furan resin composite material added with graphene.

[0011] Preferably, in Step 1, the dosage ratio of furan resin to 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, with a viscosity of 200 - 500 mPa·s and a purity of ≥95%. The curing agent is composed of one or more of p - toluenesulfonic acid, benzenesulfonic acid and phosphoric acid. The stirring speed during stirring is 200 - 250 rpm, and the continuous stirring time is 10 - 25 min.

[0012] Preferably, in Step 2, the dosage ratio of the modified toughening agent to the premixed resin is (5 - 8) g : (110 - 118) g. The temperature of continuous heating and stirring is 48 - 53°C, the continuous stirring time is 30 - 45 min, and the stirring speed is 200 - 250 rpm.

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

[0014] Q1: Under a nitrogen atmosphere, add ethyl carbazate into a reaction container filled with anhydrous tetrahydrofuran, stir, add hexamethylene diisocyanate into anhydrous tetrahydrofuran, after stirring and mixing, slowly drop it into the reaction container, continuously stir at low temperature, stand still, continue to stir, wash, and vacuum dry to obtain Compound 1;

[0015] Q2: Add Compound 1 into anhydrous ethanol, stir to obtain a mixed solution, then add anhydrous potassium carbonate, heat to reflux and stir. After the reflux ends, carry out suction filtration, dissolve the crude product, adjust the pH, filter, wash, and vacuum dry to obtain Compound 2;

[0016] Q3: Add nitric acid into silica gel, stir and mix, wash, and carry out vacuum filtration to obtain silicon nitrate. Add silicon nitrate and Compound 2 into a container filled with dichloromethane, stir at room temperature, filter, add anhydrous magnesium sulfate into the filtrate for mixing, filter, wash, and rotary evaporate to obtain Compound 3;

[0017] Q4: Add Compound 3 into acetonitrile, stir and mix to obtain Solution a. Add 2,3-diphenylindole into acetonitrile, stir and mix to obtain Solution b. Then mix Solution a and Solution b, let it stand, concentrate under vacuum, purify, and dry under vacuum to obtain the modified toughening agent.

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

[0019]

[0020] The results of mass spectrometry analysis of Compound 1 are: m / z: 376.21 (100.0%), 377.21 (15.7%), 378.21 (2.7%), 377.20 (2.2%); The results of mass spectrometry analysis of Compound 2 are: m / z: 284.12 (100.0%), 285.13 (11.2%), 285.12 (2.2%), 286.13 (1.4%); The results of mass spectrometry analysis of Compound 3 are: m / z: 280.09 (100.0%), 281.10 (11.1%), 281.09 (2.2%), 282.10 (1.4%); The results of mass spectrometry analysis of the modified toughening agent are: 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 dosage 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 °C, the stirring time is 10 - 12 min, the standing time is 2 - 4 min, the continued stirring time is 120 - 150 min, and it is washed with anhydrous tetrahydrofuran; in Q2, the dosage ratio of Compound 1, absolute 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 with distilled water after freezing treatment, 1 mol / L hydrochloric acid is added dropwise at 0 - 1 °C to adjust the pH = 1 - 2, and it is washed with ice-cold distilled water.

[0022] Preferably, in Q3, the dosage ratio of nitric acid and silica gel is (5-8) mL: (2.8-3.6) g, the volume fraction of nitric acid is 65vt%, the stirring mixing time is 15-20 min, and the product is washed with dichloromethane. The dosage ratio 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 product is washed with dichloromethane. In Q4, the dosage ratio 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, and the eluent used in the purification process is a mixed solution of ethyl acetate and petroleum ether in a volume ratio of 1:2, and the vacuum drying time is 10-12 h.

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

[0024] Preferably, the method for preparing the modified graphene comprises the following steps:

[0025] S1: Add eugenol, deionized water and ammonia water to a container containing acetone, stir, and then slowly drop a saturated aqueous solution of potassium ferrocyanide into the container. After the dropwise addition is completed, stir to react. After the reaction is completed, filter, acidify, wash, and vacuum dry to obtain intermediate A; heat and melt 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, then add intermediate A, heat and react under nitrogen protection, and cool after the reaction is completed to obtain intermediate B;

[0026] S2: adding intermediate B, 2,6-naphthalenediol, 2,6-dichlorobenzonitrile and potassium carbonate into a container, and then sequentially adding toluene and N-methylpyrrolidone, stirring thoroughly, heating to react, cooling to solidify, soaking, boiling, and vacuum drying to obtain intermediate C;

[0027] S3: Add the intermediate C to N-methylpyrrolidone, stir to dissolve, add graphene, continue stirring, and solidify to obtain modified graphene.

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

[0029]

[0030] The results of mass spectrometry analysis of intermediate A are: m / z: 326.15 (100.0%), 327.16 (22.0%), 328.16 (3.1%); the results of mass spectrometry analysis of intermediate B are: 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 dosage ratio of eugenol, deionized water, ammonia water, acetone and saturated aqueous solution of potassium ferricyanide 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 °C, the reaction time is 16 - 20 h, acidification is carried out with 1 mol / L hydrochloric acid, washing is carried out with deionized water, the vacuum drying temperature is 50 - 60 °C, and the time is 20 - 28 h; the dosage 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 °C, the temperature for the temperature - rising reaction is 160 - 165 °C, and the reaction time is 8 - 10 h.

[0032] Preferably, in S2, the dosage 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 °C, it is added to distilled water for cooling and solidification, added to 1 mol / L hydrochloric acid for soaking, added to distilled water for boiling, the vacuum drying temperature is 100 - 120 °C, and the time is 12 - 15 h; in S3, the dosage ratio of intermediate C, N - methylpyrrolidone and graphene is (2 - 5) g : (20 - 30) mL : (1 - 1.6) g, and the curing process is: maintaining at 80 °C for 1 h, maintaining at 100 °C for 1 h, maintaining at 120 °C for 1 h, maintaining at 160 °C for 2 h, maintaining at 200 °C for 2 h, maintaining at 230 °C for 2 h.

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

[0034] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are as follows:

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

[0036] 2. Adding the prepared modified toughening agent to the preparation process of the composite material can effectively improve its toughness. The C-N bond introduced in the modified toughening agent can absorb energy when broken, prevent stress concentration at the crack tip, delay crack propagation, and the large number of microcracks formed can increase the fracture surface energy, thereby increasing toughness. The hexamethylene chain contained has high flexibility and interpenetrates the rigid aromatic network of the furan resin, reducing the crosslinking point density, enhancing the mobility of molecular segments, and improving the toughness of the composite material.

[0037] 3. Adding the prepared modified graphene to the preparation process of the composite material can effectively improve its toughness, thermal stability, and electrical conductivity. The modified graphene can form a strong interfacial bond with the resin matrix. The conjugated structure contained can enhance stress transfer, and the hydrogen bond interaction can inhibit interfacial slip, improving toughness. The phosphorus group contained in the modified graphene can also improve the flame retardancy of the composite material, and the high thermal conductivity of graphene can accelerate heat diffusion. The rigid conjugated network inhibits the thermal movement of molecular chains, improving thermal stability. At the same time, the presence of graphene can endow the composite material with electrical conductivity. Specific Embodiments

[0038] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0039] Example 1: This example discloses a preparation method of a modified toughening agent, which includes the following steps:

[0040] Q1: Under a nitrogen atmosphere, 9.85 g of ethyl hydrazinecarboxylate was added to a reaction vessel containing 60 mL of anhydrous tetrahydrofuran and stirred. 8.57 g of hexamethylene diisocyanate was added to 60 mL of anhydrous tetrahydrofuran, and after stirring and mixing, it was slowly added dropwise to the reaction vessel. Stirring was continued at 0 °C for 12 min, allowed to stand for 4 min, and then stirring was continued for 120 min. It was washed with anhydrous tetrahydrofuran and dried under vacuum to obtain Compound 1;

[0041] Q2: 10 g of Compound 1 was added to 305 mL of anhydrous ethanol and stirred to obtain a mixed solution. Then 12.4 g of anhydrous potassium carbonate was added, and the mixture was heated under reflux and stirred for 24 h. After the reflux ended, filtration was carried out. The crude product was dissolved in distilled water treated by freezing, and 1 mol / L hydrochloric acid was added dropwise at 0 °C to adjust the pH to 1.3. Filtration was carried out, and it was washed with ice-cold distilled water and dried under vacuum to obtain Compound 2;

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

[0043] Q4: 0.84 g of Compound 3 was added to 10 mL of acetonitrile and stirred and mixed to obtain Solution a. 1.73 g of 2,3-diphenylindole was added to 12 mL of acetonitrile and stirred and mixed to obtain Solution b. Then Solution a and Solution b were mixed, allowed to stand for 12 h, vacuum concentrated, and 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 it was dried under vacuum for 12 h to obtain the modified toughening agent.

[0044] This example discloses a preparation method of modified graphene, including the following steps:

[0045] S1: 10 g of eugenol, 62.5 mL of deionized water, and 67.5 mL of ammonia water were added to a container containing 110 mL of acetone and stirred for 10 min. Then 55 mL of a saturated aqueous solution of potassium ferricyanide was slowly added dropwise to the container. After the addition was completed, the mixture was stirred and reacted at 28 °C for 18 h. After the reaction ended, filtration was carried out, acidified with 1 mol / L hydrochloric acid, washed with deionized water, and dried under vacuum at 55 °C 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 °C, and then 16 g of Intermediate A was added. Under nitrogen protection, the temperature was raised to 165 °C and the reaction was carried out for 10 h. After the reaction ended, it was cooled to obtain Intermediate B;

[0046] S2: Add 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 into a container. Then, add 22.5 mL of toluene and 65 mL of N - methylpyrrolidone in sequence. After stirring well, heat - react at 160 °C. After the reaction ends, add it to distilled water for cooling and solidification, soak it in 1 mol / L hydrochloric acid, boil it in distilled water, and dry it under vacuum at 100 °C for 15 h to obtain intermediate C;

[0047] S3: Add 3.5 g of intermediate C into 25 mL of N - methylpyrrolidone. After stirring and dissolving, add 1.3 g of graphene and continue stirring and curing. The curing process is as follows: keep at 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, 230 °C for 2 h to obtain modified graphene.

[0048] This example discloses a preparation method of a furan resin composite material added with graphene, including the following steps:

[0049] Step 1: Add 110 g of furfuryl alcohol resin (viscosity is 350 mPa·s, purity ≥ 95%) into a container. During stirring, add 2.2 g of p - toluenesulfonic acid and stir at 220 rpm for 20 min to obtain a premixed resin;

[0050] Step 2: Slowly add 6.5 g of a modified toughening agent into 114 g of the premixed resin, heat at 50 °C and continuously stir at 250 rpm for 45 min to obtain a toughened mixture;

[0051] Step 3: Add 4.5 g of modified graphene into 90 mL of ethanol. After ultrasonic dispersion for 20 min, drip it into 112.5 g of the toughened mixture at a rate of 2 mL / min, and stir at a high speed of 6000 rpm to obtain a composite mixture. Vacuum - defoam the composite mixture at (-0.2 MPa, 45 °C) for 30 min, then add it into a mold and cure. The curing process is as follows: first, stand still at 25 °C for 4 h, then heat up to 80 °C at a rate of 2 °C / min and cure for 2 h, then heat up to 120 °C and cure for 3 h, and finally heat up to 160 °C and cure for 1 h to obtain a furan resin composite material added with graphene.

[0052] Example 2: This example discloses a preparation method of a modified toughening agent, including the following steps:

[0053] Q1: Under a nitrogen atmosphere, 9.23 g of ethyl hydrazinecarboxylate was added to a reaction vessel containing 60 mL of anhydrous tetrahydrofuran and stirred. 7.89 g of hexamethylene diisocyanate was added to 60 mL of anhydrous tetrahydrofuran, stirred and mixed, then slowly added dropwise to the reaction vessel. Stirring was continued at 0 °C for 12 min, left to stand for 4 min, and then stirring was continued for 120 min. It was washed with anhydrous tetrahydrofuran and dried under vacuum to obtain Compound 1;

[0054] Q2: 8 g of Compound 1 was added to 280 mL of anhydrous ethanol and stirred to obtain a mixed solution. Then 10.2 g of anhydrous potassium carbonate was added, and the mixture was heated under reflux and stirred for 24 h. After the reflux ended, filtration was carried out. The crude product was dissolved in distilled water treated by freezing, and 1 mol / L hydrochloric acid was added dropwise at 0 °C to adjust the pH to 1.3. Filtration was carried out, and it was washed with ice-cold distilled water and dried under vacuum to obtain Compound 2;

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

[0056] Q4: 0.75 g of Compound 3 was added to 10 mL of acetonitrile and stirred and mixed to obtain Solution a. 1.61 g of 2,3-diphenylindole was added to 12 mL of acetonitrile and stirred and mixed to obtain Solution b. Then Solution a and Solution b were mixed, left to stand for 12 h, vacuum concentrated and 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 dried under vacuum for 12 h to obtain a modified toughening agent.

[0057] This example discloses a preparation method of modified graphene, including the following steps:

[0058] S1: 8 g of eugenol, 50 mL of deionized water and 60 mL of ammonia water were added to a container containing 120 mL of acetone and stirred for 10 min. Then 45 mL of a saturated aqueous solution of potassium ferricyanide was slowly added dropwise to the container. After the addition was completed, stirring reaction was carried out at 28 °C for 18 h. After the reaction ended, filtration was carried out, acidified with 1 mol / L hydrochloric acid, washed with deionized water, and vacuum dried at 55 °C for 24 h to obtain Intermediate A; 20 g of 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was heated and melted at 135 °C, and then 15 g of Intermediate A was added. Under nitrogen protection, the temperature was raised to 165 °C and the reaction was carried out for 10 h. After the reaction ended, it was cooled to obtain Intermediate B;

[0059] S2: Add 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 into a container. Then, add 20 mL of toluene and 60 mL of N-methylpyrrolidone in sequence. After stirring well, heat and react at 160 °C. After the reaction ends, add it to distilled water for cooling and solidification, soak it in 1 mol / L hydrochloric acid, boil it in distilled water, and dry it under vacuum at 100 °C for 15 h to obtain intermediate C;

[0060] S3: Add 2 g of intermediate C into 20 mL of N-methylpyrrolidone. After stirring and dissolving, add 1 g of graphene and continue stirring and curing. The curing process is as follows: maintain at 80 °C for 1 h, 100 °C for 1 h, 120 °C for 1 h, 160 °C for 2 h, and 200 °C for 2 h, and 230 °C for 2 h to obtain modified graphene.

[0061] This example discloses a preparation method of a furan resin composite material added with graphene, including the following steps:

[0062] Step 1: Add 100 g of furfuryl alcohol resin (viscosity is 350 mPa·s, purity ≥ 95%) into a container. During stirring, add 2 g of p-toluenesulfonic acid and stir at 220 rpm for 20 min to obtain a premixed resin;

[0063] Step 2: Slowly add 5 g of a modified toughening agent into 110 g of the premixed resin, heat at 50 °C, and continuously stir at 250 rpm for 45 min to obtain a toughened mixture;

[0064] Step 3: Add 3 g of modified graphene into 80 mL of ethanol. After ultrasonic dispersion for 20 min, dropwise add it to 110 g of the toughened mixture at a rate of 2 mL / min, and stir at a high speed of 6000 rpm to obtain a composite mixture. Vacuum degas the composite mixture at (-0.2 MPa, 45 °C) for 30 min, then add it into a mold and cure. The curing process is as follows: first, let it stand at 25 °C for 4 h, then heat it to 80 °C at a rate of 2 °C / min and cure for 2 h, then heat it to 120 °C and cure for 3 h, and finally heat it to 160 °C and cure for 1 h to obtain a furan resin composite material added with graphene.

[0065] Example 3: This example discloses a preparation method of a modified toughening agent, including the following steps:

[0066] Q1: Under a nitrogen atmosphere, 10.38 g of ethyl hydrazinecarboxylate was added to a reaction vessel containing 60 mL of anhydrous tetrahydrofuran and stirred. 8.35 g of hexamethylene diisocyanate was added to 60 mL of anhydrous tetrahydrofuran, stirred and mixed, then slowly added dropwise to the reaction vessel. Stirring was continued at 0 °C for 12 min, left standing for 4 min, and then stirring was continued for 120 min. It was washed with anhydrous tetrahydrofuran and dried under vacuum to obtain Compound 1;

[0067] Q2: 12 g of Compound 1 was added to 330 mL of anhydrous ethanol and stirred to obtain a mixed solution. Then 14.7 g of anhydrous potassium carbonate was added, and the mixture was heated under reflux and stirred for 24 h. After the reflux ended, filtration was carried out. The crude product was dissolved in distilled water treated by freezing, and 1 mol / L hydrochloric acid was added dropwise at 0 °C to adjust the pH to 1.3. Filtration was carried out, and it was washed with ice-cold distilled water and dried under vacuum to obtain Compound 2;

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

[0069] Q4: 0.93 g of Compound 3 was added to 10 mL of acetonitrile and stirred and mixed to obtain Solution a. 1.88 g of 2,3-diphenylindole was added to 12 mL of acetonitrile and stirred and mixed to obtain Solution b. Then Solution a and Solution b were mixed, left standing for 12 h, vacuum concentrated, and 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 dried under vacuum for 12 h to obtain the modified toughening agent.

[0070] This example 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 to a container containing 100 mL of acetone and stirred for 10 min. Then 65 mL of a saturated aqueous solution of potassium ferricyanide was slowly added dropwise to the container. After the addition was completed, stirring reaction was carried out at 28 °C for 18 h. After the reaction ended, filtration was carried out, acidified with 1 mol / L hydrochloric acid, washed with deionized water, and vacuum dried at 55 °C 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 °C, and then 17 g of Intermediate A was added. Under nitrogen protection, the temperature was raised to 165 °C and the reaction was carried out for 10 h. After the reaction ended, it was cooled to obtain Intermediate B;

[0072] S2: Add 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 into a container. Then, add 25 mL of toluene and 70 mL of N - methylpyrrolidone in sequence. After stirring well, heat and react at 160 °C. After the reaction is completed, add it to distilled water for cooling and solidification, soak it in 1 mol / L hydrochloric acid, boil it in distilled water, and dry it under vacuum at 100 °C for 15 h to obtain intermediate C;

[0073] S3: Add 5 g of intermediate C into 30 mL of N - methylpyrrolidone. After stirring and dissolving, add 1.6 g of graphene, and continue to stir and cure. The curing process is as follows: keep at 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] This example discloses a preparation method of a furan resin composite material added with graphene, including the following steps:

[0075] Step 1: Add 120 g of furfuryl alcohol resin (viscosity is 350 mPa·s, purity ≥ 95%) into a container. During stirring, add 2.4 g of p - toluenesulfonic acid, and stir at 220 rpm for 20 min to obtain a premixed resin;

[0076] Step 2: Slowly add 8 g of modified toughening agent into 118 g of premixed resin, heat at 50 °C, and continuously stir at 250 rpm for 45 min to obtain a toughened mixture;

[0077] Step 3: Add 6 g of modified graphene into 100 mL of ethanol. After ultrasonic dispersion for 20 min, drop it into 115 g of toughened mixture at a rate of 2 mL / min, and stir at a high speed of 6000 rpm to obtain a composite mixture. Vacuum degas the composite mixture at (-0.2 MPa, 45 °C) for 30 min, then add it into a mold and cure. The curing process is as follows: first, stand still at 25 °C for 4 h, then heat up to 80 °C at a rate of 2 °C / min and cure for 2 h, then heat up to 120 °C and cure for 3 h, and finally heat up to 160 °C and cure for 1 h to obtain a furan resin composite material added with graphene.

[0078] Example 4: This example discloses a preparation method of a modified toughening agent, including the following steps:

[0079] Q1: Under a nitrogen atmosphere, 9.54 g of ethyl hydrazinecarboxylate was added to a reaction vessel containing 60 mL of anhydrous tetrahydrofuran and 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. Stirring was continued at 0 °C for 12 min, left standing for 4 min, and then stirring was continued for 120 min. It was washed with anhydrous tetrahydrofuran and dried under vacuum to obtain Compound 1;

[0080] Q2: 9 g of Compound 1 was added to 295 mL of anhydrous ethanol and stirred to obtain a mixed solution. Then 11.3 g of anhydrous potassium carbonate was added, and the mixture was heated under reflux and stirred for 24 h. After the reflux ended, suction filtration was carried out. The crude product was dissolved in distilled water treated by freezing, and 1 mol / L hydrochloric acid was added dropwise at 0 °C to adjust the pH to 1.3. Filtration was carried out, and it was washed with ice-cold distilled water and dried under vacuum 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, and vacuum filtered to obtain silicon nitrate. 1.1 g of silicon nitrate 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, anhydrous magnesium sulfate was added to the filtrate and mixed 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 and stirred and mixed to obtain Solution a. 1.65 g of 2,3-diphenylindole was added to 12 mL of acetonitrile and stirred and mixed to obtain Solution b. Then Solution a and Solution b were mixed, left standing for 12 h, vacuum concentrated, and 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 dried under vacuum for 12 h to obtain a modified toughening agent.

[0083] This example discloses a preparation method of modified graphene, including 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 and stirred for 10 min. Then 50 mL of a saturated aqueous solution of potassium ferricyanide was slowly added dropwise to the container. After the addition was completed, stirring reaction was carried out at 28 °C for 18 h. After the reaction ended, filtration was carried out, acidified with 1 mol / L hydrochloric acid, washed with deionized water, and dried under vacuum at 55 °C for 24 h to obtain Intermediate A; 20.8 g of 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was melted by heating at 135 °C, and then 15.5 g of Intermediate A was added. Under nitrogen protection, the temperature was raised to 165 °C and the reaction was carried out for 10 h. After the reaction ended, it was cooled to obtain Intermediate B;

[0085] S2: Add 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 into a container. Then, add 21 mL of toluene and 62 mL of N-methylpyrrolidone in sequence. After stirring well, heat the mixture at 160 °C for reaction. After the reaction is completed, add it to distilled water for cooling and solidification, soak it in 1 mol / L hydrochloric acid, boil it in distilled water, and dry it under vacuum at 100 °C for 15 h to obtain intermediate C;

[0086] S3: Add 3 g of intermediate C into 22 mL of N-methylpyrrolidone. After stirring and dissolving, add 1.2 g of graphene and continue stirring and curing. The curing process is as follows: maintain at 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] This example discloses a preparation method of a furan resin composite material added with graphene, including the following steps:

[0088] Step 1: Add 105 g of furfuryl alcohol resin (viscosity is 350 mPa·s, purity ≥ 95%) into a container. During stirring, add 2.1 g of p-toluenesulfonic acid and stir at 220 rpm for 20 min to obtain a premixed resin;

[0089] Step 2: Slowly add 6 g of modified toughening agent into 112 g of premixed resin, heat at 50 °C and continuously stir at 250 rpm for 45 min to obtain a toughened mixture;

[0090] Step 3: Add 4 g of modified graphene into 95 mL of ethanol. After ultrasonic dispersion for 20 min, drop it into 111 g of toughened mixture at a rate of 2 mL / min, stir at a high speed of 6000 rpm to obtain a composite mixture. Vacuum degas the composite mixture at (-0.2 MPa, 45 °C) for 30 min, then add it into a mold and cure it. The curing process is as follows: first, stand still at 25 °C for 4 h, then heat up to 80 °C at a rate of 2 °C / min and cure for 2 h, then heat up to 120 °C and cure for 3 h, and finally heat up to 160 °C and cure for 1 h to obtain a furan resin composite material added with graphene.

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

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

[0093] Experimental Example: The properties of the furan resin composites added with graphene 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. The test results are shown in Table 1:

[0094] Table 1

[0095] Project 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 <![CDATA[2.41×10 3 >

[0096] As can be seen from the test results in Table 1, the composites prepared in Examples 1-4 of the present invention have excellent toughness, thermal stability and electrical conductivity. By comparing Comparative Example 1 with Examples 1-4, it can be seen that adding a modified toughening agent can effectively improve the toughness of the composite material, and adding modified graphene can effectively improve the toughness, thermal stability and electrical conductivity of the material.

[0097] Aging resistance. By comparing Comparative Example 2 with Examples 2-5, it can be seen that adding N-butyl-2,2,6,6-tetramethyl-4-piperidinamine can effectively improve the aging resistance of the charging cable.

[0098] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

[0099] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the present invention to only the specific embodiments. Obviously, according to the content of this specification, many modifications and changes can be made. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and utilize the present invention well. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. Preparation method of furan resin composite material added with graphene, characterized in that, It includes the following steps: Step 1: Add furan resin into a container, add a curing agent during stirring, and keep stirring to obtain a premixed resin. Step 2: Slowly add a modified toughening agent into the premixed resin, heat and keep stirring to obtain a toughened mixture. Step 3: Add modified graphene into ethanol, after ultrasonic dispersion, slowly drop it into the toughened mixture, stir at high speed to obtain a composite mixture, subject the composite mixture to vacuum degassing, then add it into a mold and cure it to obtain a furan resin composite material added with graphene.

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

3. The preparation method of the furan resin composite material added with graphene according to claim 1, characterized in that, In the said Step 2, the dosage ratio of the modified toughening agent to the premixed resin is (5 - 8) g : (110 - 118) g, the temperature for heating and continuous stirring is 48 - 53 °C, and the continuous stirring time is 30 - 45 min.

4. The preparation method of the furan resin composite material added with graphene according to claim 1, characterized in that, The preparation method of the said modified toughening agent includes the following steps: Q1: Under a nitrogen atmosphere, add ethyl hydrazinecarboxylate into a reaction container filled with anhydrous tetrahydrofuran, stir, add hexamethylene diisocyanate into anhydrous tetrahydrofuran, after stirring and mixing, slowly drop it into the reaction container, keep stirring at low temperature, let it stand, continue stirring, wash, and vacuum dry to obtain Compound 1. Q2: Add Compound 1 into anhydrous ethanol, stir to obtain a mixed solution, then add anhydrous potassium carbonate, heat to reflux and stir, after the reflux ends, filter by suction, dissolve the crude product, adjust the pH, filter, wash, and vacuum dry to obtain Compound 2. Q3: Add nitric acid into silica gel, stir and mix, wash, vacuum filter to obtain silicon nitrate, add silicon nitrate and Compound 2 into a container filled with dichloromethane, stir at room temperature, filter, add anhydrous magnesium sulfate into the filtrate for mixing, filter, wash, and rotary evaporate to obtain Compound 3. Q4: Add Compound 3 into acetonitrile, stir and mix to obtain Solution a, add 2,3 - diphenylindole into acetonitrile, stir and mix to obtain Solution b, then mix Solution a and Solution b, let it stand, vacuum concentrate, purify, and vacuum dry to obtain the modified toughening agent.

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

6. The preparation method of the furan resin composite material added with graphene according to claim 4, characterized in that, In the said Q3, the dosage ratio of nitric acid to silica gel is (5 - 8) mL : (2.8 - 3.6) g, the dosage ratio of silicon nitrate, Compound 2 and dichloromethane is (1 - 1.5) g : (0.42 - 0.58) g : (12 - 18) mL; in the said Q4, the dosage ratio of Compound 3 to 2,3 - diphenylindole is (0.75 - 0.93) g : (1.61 - 1.88) g.

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

8. The preparation method of the furan resin composite material added with graphene according to claim 1, characterized in that, The preparation method of the modified graphene comprises the following steps: S1: Add eugenol, deionized water and ammonia water to a container containing acetone, stir, and then slowly drop a saturated aqueous solution of potassium ferrocyanide into the container. After the dropwise addition is completed, stir to react. After the reaction is completed, filter, acidify, wash, and vacuum dry to obtain intermediate A; heat and melt 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, then add intermediate A, heat and react under nitrogen protection, and cool after the reaction is completed to obtain intermediate B; S2: adding intermediate B, 2,6-naphthalenediol, 2,6-dichlorobenzonitrile and potassium carbonate into a container, and then sequentially adding toluene and N-methylpyrrolidone, stirring thoroughly, heating to react, cooling to solidify, soaking, boiling, and vacuum drying to obtain intermediate C; S3: Add the intermediate C to N-methylpyrrolidone, stir to dissolve, add graphene, continue stirring, and solidify to obtain modified graphene.

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

10. The preparation method of the furan resin composite material added with graphene according to claim 8, characterized in that, In S2, the usage 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; in S3, the usage ratio of intermediate C, N-methylpyrrolidone and graphene is (2-5) g: (20-30) mL: (1-1.6) g.

11. A graphene-added furan resin composite material prepared by the method according to any one of claims 1 to 10.

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