Castor oil-based toughened high thermal conductivity materials, their preparation methods and applications

Abstract

This invention discloses a castor oil-based toughened high thermal conductivity material, its preparation method, and its applications. The preparation method includes: grafting isocyanate groups onto the bio-based chemical castor oil using silane coupling agent-amined graphene. The flexible long carbon chains and urethane groups of castor oil can toughen thermosetting polymers, while graphene can provide thermal conductivity. The material prepared by this invention can provide both toughening and thermal conductivity to thermosetting polymers.

Description

Technical Field

[0001] This invention belongs to the field of polymer composite materials, specifically relating to a method for preparing a castor oil-based toughened high thermal conductivity material and its application. Background Technology

[0002] Current research on the preparation of high thermal conductivity materials based on thermosetting resins primarily relies on the advantages of their three-dimensional network structure formed during curing, such as excellent rigidity, hardness, heat resistance, dimensional stability, and chemical resistance. However, this highly cross-linked structure also brings significant drawbacks: restricted molecular chain movement leads to insufficient material toughness and high brittleness, specifically manifested as low impact strength, low elongation at break, and poor fracture toughness. More importantly, excessively high cross-linking density not only limits the thermal conductivity of the matrix itself but also hinders the heat dissipation efficiency of the added thermally conductive fillers. This makes the material prone to localized overheating when used as a filler, which not only damages the material's own properties but also seriously affects the reliability of the final application product.

[0003] Therefore, developing a preparation process and optimization scheme for thermosetting materials that combine high thermal conductivity and excellent toughness is crucial to meeting the needs of various filler application scenarios. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing a castor oil-based toughened high thermal conductivity material and its application, overcoming the defects of existing materials in the background art, and partially or completely solving the technical problem of how to improve and optimize the material preparation process based on castor oil and modified graphene oxide to obtain a material that improves the high thermal conductivity of thermosetting materials while ensuring its high toughness.

[0005] To address the above technical problems, the first aspect of this invention provides a method for preparing a castor oil-based toughened high thermal conductivity material, comprising: modifying graphene oxide by amination with a silane coupling agent; grafting the modified graphene oxide onto the bio-based chemical castor oil via isocyanate groups to form a castor oil-based toughened high thermal conductivity material having the toughening properties of the compliant long carbon chains of castor oil and the toughening properties of urethane groups, combined with the high thermal conductivity of the modified graphene oxide.

[0006] Among them, the modification of graphene oxide by silane coupling agent includes: modifying graphene oxide with 3-aminopropyltriethoxysilane to obtain silane coupling agent-modified graphene oxide.

[0007] Specifically, the method involves modifying graphene oxide with 3-aminopropyltriethoxysilane to obtain silane coupling agent-amined graphene oxide. This includes adding graphene oxide to an ethanol solution of 3-aminopropyltriethoxysilane at a concentration of 3wt%-5wt% to obtain amination-modified graphene oxide.

[0008] The method involves adding graphene oxide to an ethanol solution of 3-aminopropyltriethoxysilane at a concentration of 3wt%-5wt% to obtain amination-modified graphene oxide. Specifically, this includes: adding graphene oxide to an ethanol solution of 3-aminopropyltriethoxysilane at a concentration of 3wt%-5wt%, wherein the mass ratio of graphene oxide to 3-aminopropyltriethoxysilane is 1:(0.01-0.2); heating and maintaining the temperature at 40-60℃ while stirring the solution for 4-8 hours; and then centrifuging, washing with anhydrous ethanol, and drying to obtain modified graphene oxide.

[0009] The modified graphene oxide obtained has 1 to 10 layers and a thickness of 0.2 to 10 nm.

[0010] The method involves grafting modified graphene oxide onto the bio-based chemical castor oil via isocyanate groups. This includes dispersing castor oil and amino-modified graphene oxide in a solvent, then adding isocyanate dropwise at low temperature to carry out the reaction, and finally evaporating the solvent after the reaction to obtain a castor oil-based toughened high thermal conductivity material.

[0011] The solvent includes any one of anhydrous acetone, butanone, toluene, and DMF; the isocyanate is any one of TDI, MDI, HDI, and IPDI; during the reaction, the mass ratio of castor oil, amination-modified graphene oxide, and isocyanate is 1:(0.02-0.08):(0.03-0.06).

[0012] The process involves grafting modified graphene oxide onto the bio-based chemical castor oil via isocyanate groups. Specifically, this includes: adding castor oil and amino-modified graphene oxide into a solvent; ultrasonically dispersing at room temperature for 15-30 minutes; then transferring the solvent to an oil bath at 25-45 °C and slowly adding isocyanate to react, controlling the reaction time to 2-4 hours until the NCO groups disappear; finally, rotary evaporation to remove the solvent, yielding a castor oil-based toughened high thermal conductivity material.

[0013] To address the above technical problems, a second aspect of the present invention provides a castor oil-based toughened high thermal conductivity material for improving the toughness and thermal conductivity of thermosetting resins, wherein the material is prepared by any of the preparation methods described in the first aspect above.

[0014] To address the above technical problems, a third aspect of the present invention provides an application of the castor oil-based toughened high thermal conductivity material of the second aspect mentioned above, said material being used to improve the toughness and thermal conductivity of thermosetting resins.

[0015] Compared with existing technologies, this invention utilizes silane coupling agents to amination-modify graphene oxide, which is then grafted onto the bio-based chemical castor oil via isocyanate groups. The long, flexible carbon chains of castor oil provide molecular chain flexibility, alleviating stress concentration, and the combination with urethane groups forms a flexible network structure, enhancing material toughness and providing toughening for thermosetting polymers such as thermosetting resins. Simultaneously, the addition of coupling agents to the organosilicon elastomer yields amination-modified graphene oxide, improving its dispersibility in the castor oil matrix and increasing its thermal conductivity to 1.8 W / mK3, providing excellent thermal conductivity for thermosetting polymers such as thermosetting resins. The material prepared by this invention can provide both toughening and thermal conductivity for thermosetting polymers.

[0016] Furthermore, the material prepared by the present invention is obtained by reacting isocyanate, silane coupling agent amination-modified graphene oxide with castor oil, and its thermal conductivity is effectively improved. For example, when used as a filler, it has excellent properties such as reducing interfacial thermal resistance and increasing thermal conductivity to 1.8 W / mK3.

[0017] In addition, the improved and optimized materials and preparation methods of this invention, such as castor oil-based raw materials, are renewable, thus optimizing the field of environmentally friendly green materials and processes. Attached Figure Description

[0018] To make the technical problems solved by the present invention, the technical means adopted, and the technical effects achieved clearer, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, it should be noted that the drawings described below are merely drawings of exemplary embodiments of the present invention. Those skilled in the art can obtain drawings of other embodiments based on these drawings without any creative effort.

[0019] Figure 1 This is a schematic diagram of the process flow of a specific embodiment of the preparation method of the castor oil-based toughened high thermal conductivity material of this application.

[0020] Figure 2 This is a comparison between the material obtained by a specific embodiment of the preparation method of this application and the material prepared by the prior art. Detailed Implementation

[0021] Exemplary embodiments of the invention will now be described more fully. However, these exemplary embodiments can be implemented in many forms and should not be construed as limiting the invention to the embodiments set forth herein. Rather, these exemplary embodiments are provided to make the invention more comprehensive and complete, and to facilitate a full communication of the inventive concept to those skilled in the art.

[0022] The terms “and / or” or “and / or” include any one or more of the listed items in relation to each other.

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the preparation method of the castor oil-based toughened high thermal conductivity material of this invention will be further described in detail below with reference to specific embodiments.

[0024] Example 1 In one specific embodiment, the preparation method of the castor oil-based toughened high thermal conductivity material includes the following specific process steps: S110: Graphene oxide modified by amination with silane coupling agent.

[0025] Specifically, silane coupling agent-modified graphene oxide involves using aminosilane coupling agents through hydrolysis, condensation, and bonding to form an amino-functionalized layer. This is achieved by constructing a reactive amine-containing silicone film on the surface of graphene oxide, creating a molecular bridge between the organic and inorganic phases. The modified graphene oxide exhibits significantly enhanced interfacial adhesion strength, improved mechanical properties and durability, and facilitates dispersion and interfacial bonding within the polymer matrix of subsequently prepared materials.

[0026] Preferably, the aminosilane coupling agent is aminopropylsilane, specifically 3-aminopropyltriethoxysilane.

[0027] In one embodiment, the modification of graphene oxide by amination with a silane coupling agent includes: modifying graphene oxide with 3-aminopropyltriethoxysilane to obtain silane coupling agent-amination-modified graphene oxide.

[0028] Specifically, graphene oxide is added to a solution containing 3-aminopropyltriethoxysilane. The siloxane of this coupling agent reacts chemically with the oxygen-containing functional groups on the surface of graphene oxide to form covalent bonds, thereby improving the dispersibility of graphene oxide and its compatibility with other materials.

[0029] Preferably, graphene oxide can be added to an ethanol solution of 3-aminopropyltriethoxysilane with a concentration of 3wt%-5wt% to obtain amination-modified graphene oxide, wherein the mass ratio of graphene oxide to 3-aminopropyltriethoxysilane is 1:(0.01-0.2).

[0030] A chemical reaction was carried out on an ethanol solution containing 3wt%-5wt% of 3-aminopropyltriethoxysilane to modify the graphene oxide, such as forming a covering network or dendritic structure on the surface of the graphene oxide.

[0031] Preferably, the ethanol solution containing graphene oxide and 3-aminopropyltriethoxysilane is heated to 40°C and maintained in the temperature range of 40-60°C while being stirred simultaneously, and the solution reaction is maintained for at least 4 hours (4 hours). Specifically, the stirring time is controlled within the range of 4-8 hours. After that, the modified graphene oxide is obtained by centrifugation, washing with anhydrous ethanol and drying.

[0032] Preferably, the modified graphene oxide obtained has 1 to 10 layers and a thickness of 0.2 to 10 nm.

[0033] S120: Modified graphene oxide is grafted onto the bio-based chemical castor oil via isocyanate groups.

[0034] Specifically, castor oil and amination-modified graphene oxide are dispersed in a solvent, and then isocyanate is added dropwise at low temperature to carry out the reaction. After the reaction is completed, the solvent is evaporated to obtain a castor oil-based toughened high thermal conductivity material.

[0035] Castor oil, as a natural polyol, contains hydroxyl groups, ester bonds, and long fatty chains in its molecules. It undergoes multifunctional group reactions. Amination-modified graphene oxide is dispersed together with castor oil in a solvent. The hydroxyl groups of castor oil react with isocyanates added at low temperature and silanes or amines on the modified graphene oxide to form polyurethane or organosilicon network structures. The long carbon chains provide flexibility to the molecular chains, alleviate stress concentration, and improve the toughness of the material. The overall preparation of the material improves the dispersibility of graphene oxide and increases the thermal conductivity to 1.8 W / mK3.

[0036] Preferably, the modified graphene oxide is grafted onto the bio-based chemical castor oil via isocyanate groups, and specifically further includes adding castor oil and the amino-modified graphene oxide into a solvent for dispersion.

[0037] Preferably, the dispersion includes ultrasonic dispersion at room temperature for 15-30 minutes.

[0038] Preferably, the dispersed solvent is then transferred to an oil bath at 15-45 °C, and isocyanate is slowly added dropwise for reaction. The reaction time is controlled at 2-5 h until the NCO groups disappear. Finally, the solvent is removed by rotary evaporation to obtain castor oil-based toughened high thermal conductivity material.

[0039] Preferably, the solvent used for dispersion includes any one of anhydrous acetone, butanone, toluene, and DMF.

[0040] Preferably, the isocyanate is any one of TDI, MDI, HDI and IPDI.

[0041] Preferably, during the reaction, the mass ratio of castor oil, amination-modified graphene oxide, and isocyanate is 1:(0.02-0.08):(0.03-0.06).

[0042] Thus, a castor oil-based toughened high thermal conductivity material was formed and obtained, which features the toughening effect of castor oil's compliant long carbon chains and urethane groups, combined with the high thermal conductivity of modified graphene oxide. The toughness of thermosetting resin materials can be improved by more than 55%, and the thermal conductivity can be increased to over 1.8 W / mK3.

[0043] Example 2 S210: Graphene oxide modified by amination with silane coupling agent.

[0044] This step is basically the same as the modification treatment method and process in step S110 of Example 1.

[0045] In the process of adding graphene oxide to an ethanol solution of 3-aminopropyltriethoxysilane at a concentration of 3wt%-5wt% to obtain amination-modified graphene oxide, the mass ratio of graphene oxide to 3-aminopropyltriethoxysilane is preferably 1:0.1. Furthermore, the temperature is maintained continuously within the range of 40-60°C, preferably 55°C or 60°C, while stirring simultaneously, maintaining the solution reaction for at least 4 hours, specifically controlling the stirring time to be within the range of 4-8 hours, preferably 8 hours.

[0046] S220 involves grafting modified graphene oxide onto the bio-based chemical castor oil via isocyanate groups.

[0047] This step is basically the same as the processing method and process in step S120 of Example 1.

[0048] The oil bath temperature is 25-40℃, and the reaction time is controlled at 4.5h or 5h.

[0049] Thus, a castor oil-based toughened high thermal conductivity material was formed and obtained, featuring the toughening effect of castor oil's compliant long carbon chains and urethane groups, combined with the high thermal conductivity of modified graphene oxide. The toughness of thermosetting resin materials can be improved by more than 55%, and the thermal conductivity can be increased to over 1.8 W / mK³. Compared with Examples 1 and 3, the stable material obtained through better modification and dispersion, slower low-temperature dripping rate, and longer reaction time exhibits superior performance.

[0050] Example 3 S310: Graphene oxide modified by amination with silane coupling agent.

[0051] This step is basically the same as the modification treatment method and process in step S110 of Example 1.

[0052] In the process of adding graphene oxide to an ethanol solution of 3-aminopropyltriethoxysilane at a concentration of 3wt%-5wt% to obtain amination-modified graphene oxide, the mass ratio of graphene oxide to 3-aminopropyltriethoxysilane is preferably 1:2. Furthermore, the ethanol solution containing graphene oxide and 3-aminopropyltriethoxysilane is heated to 50°C and maintained at a temperature range of 40-60°C (not lower than 40°C), preferably 40°C or 50°C, while simultaneously stirring, maintaining the reaction time for at least 4-8 hours, preferably 5 hours.

[0053] S320 involves grafting modified graphene oxide onto the bio-based chemical castor oil via isocyanate groups.

[0054] This step is basically the same as the processing method and process in step S120 of Example 1.

[0055] Simply transfer the dispersed solvent to an oil bath at 15-45 ℃, slowly add isocyanate to carry out the reaction, control the reaction time to 2-5 h until the NCO groups disappear, preferably 5 h, the oil bath temperature is preferably 15 ℃ or 45 ℃, and the reaction time is controlled to 3 h or 4 h.

[0056] Application Examples 1-3 and Comparative Application Examples 1-2 were cured according to the recommended epoxy resin curing procedure, and the performance of the samples was then tested.

[0057] 1. Tensile strength: Tested according to GB / T 7124 method.

[0058] 2. Impact toughness: Tested according to GB / T 1043 method.

[0059] 3. Thermal conductivity test: Tested according to ASTM D5470 method.

[0060] Thus, a castor oil-based toughened high thermal conductivity material was formed and obtained, featuring the toughening effect of castor oil's compliant long carbon chains and urethane groups, combined with the high thermal conductivity of modified graphene oxide. The toughness of thermosetting resin materials can be improved by more than 55%, and the thermal conductivity can be increased to over 1.8 W / mK³. Compared with Examples 1 and 2, the modification and dispersion effect is relatively weaker, the reaction time is moderate at lower or higher temperatures, and the resulting stable material is relatively weaker than the previous two examples.

[0061] The materials obtained by the specific preparation methods of the aforementioned embodiments are castor oil-based toughened high thermal conductivity materials used to improve the toughness and thermal conductivity of thermosetting resins.

[0062] The application of the castor oil-based toughened high thermal conductivity materials prepared through the aforementioned embodiments can mainly improve the toughness and thermal conductivity of thermosetting resins.

[0063] This invention innovatively utilizes isocyanate as a bridge to covalently bond flexible, long-chain castor oil with highly thermally conductive graphene, thus preparing a novel thermally conductive and toughened material. Compared to the complex process of traditional methods that require the separate addition of toughening agents and thermally conductive fillers, this invention achieves significant toughening and improved thermal conductivity simultaneously with a single material, significantly simplifying the material formulation and preparation process.

Claims

1. A method for preparing a castor oil-based toughened high thermal conductivity material, characterized in that, include: Amination modification of graphene oxide using silane coupling agents; Modified graphene oxide is grafted onto the bio-based chemical castor oil via isocyanate groups to form a castor oil-based toughened high thermal conductivity material with the toughening of castor oil's compliant long carbon chains and urethane groups, combined with the high thermal conductivity of the modified graphene oxide.

2. The preparation method according to claim 1, characterized in that, Amination modification of graphene oxide using silane coupling agents includes: 3-Aminopropyltriethoxysilane was used to modify graphene oxide to obtain silane coupling agent-amined graphene oxide.

3. The preparation method according to claim 2, characterized in that, Graphene oxide was modified with 3-aminopropyltriethoxysilane to obtain silane coupling agent-amined graphene oxide, specifically including: Graphene oxide was added to an ethanol solution of 3-aminopropyltriethoxysilane with a concentration of 3wt%-5wt%, heated and stirred, the precipitate was collected by centrifugation and dried to obtain amination-modified graphene oxide.

4. The preparation method according to claim 3, characterized in that, Adding graphene oxide to an ethanol solution of 3-aminopropyltriethoxysilane at a concentration of 3 wt%-5 wt% yields amination-modified graphene oxide, specifically including: An ethanol solution containing 3-aminopropyltriethoxysilane at a concentration of 3wt%-5wt% of graphene oxide, wherein the mass ratio of graphene oxide to 3-aminopropyltriethoxysilane is 1:(0.01-0.2). After the solution is heated to 40-60℃ and stirred for 4-8 hours, it is then centrifuged, washed with anhydrous ethanol, and dried to obtain modified graphene oxide.

5. The preparation method according to any one of claims 1-4, characterized in that, The obtained modified graphene oxide has 1 to 10 layers and a thickness of 0.2 to 10 nm.

6. The preparation method according to any one of claims 1-5, characterized in that, Modified graphene oxide was grafted onto the bio-based chemical castor oil via isocyanate groups, including: Castor oil and amination-modified graphene oxide were dispersed in a solvent, and then isocyanate was added dropwise at low temperature to carry out the reaction. After the reaction was completed, the solvent was evaporated to obtain a castor oil-based toughened high thermal conductivity material.

7. The preparation method according to any one of claims 1-6, characterized in that, Also includes: Solvents include: any one of anhydrous acetone, butanone, toluene, and DMF; and / or, The isocyanate is any one of TDI, MDI, HDI, and IPDI; and / or, During the reaction, the mass ratio of castor oil, amination-modified graphene oxide, and isocyanate was 1:(0.02-0.08):(0.03-0.06).

8. The preparation method according to any one of claims 1-7, characterized in that, The modified graphene oxide was grafted onto the bio-based chemical castor oil via isocyanate groups, specifically including: Castor oil and amination-modified graphene oxide were added to the solvent for dispersion. Perform ultrasonic dispersion at room temperature for 15-30 minutes; Subsequently, the solvent was transferred to an oil bath at 25-45 °C, and isocyanate was slowly added dropwise to carry out the reaction. The reaction time was controlled at 2-4 h until the NCO groups disappeared. Finally, the solvent was removed by rotary evaporation to obtain a castor oil-based toughened high thermal conductivity material.

9. A castor oil-based toughened high thermal conductivity material for improving the toughness and thermal conductivity of thermosetting resins, characterized in that, The material is prepared by the preparation method according to any one of claims 1-9.

10. The application of the castor oil-based toughened high thermal conductivity material according to claim 9, characterized in that, The material is used to improve the toughness and thermal conductivity of thermosetting resins.

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