High-temperature-resistant composite material with high-toughness resin and preparation method thereof

Abstract

This invention provides a high-toughness resin for high-temperature resistant composite materials, characterized by comprising the following raw materials in parts by weight: 60-80 parts of a bifunctional main epoxy resin; 30-50 parts of a multifunctional resin; 20-40 parts of a toughening component; 15-40 parts of a curing agent; 5-20 parts of a diluent; and 0.5-2 parts of an accelerator. The bifunctional main epoxy resin is selected from one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, polyphenol type glycidyl ether epoxy resin, aliphatic glycidyl ether epoxy resin, and glycidyl ester type epoxy resin. The toughening component is selected from one or more of polyethersulfone, acrylate-modified epoxy resin, polyetheretherketone, polyurethane-modified epoxy resin, polycarbonate, carboxyl-terminated butadiene-acrylonitrile rubber-modified epoxy resin, polyimide, and silicone-modified epoxy resin. Addressing the shortcomings of existing technologies, this invention provides a high-toughness resin for high-temperature resistant and high-toughness composite materials and its preparation method.

Description

Technical Field

[0001] This invention relates to the field of composite materials, and in particular to a high-toughness resin for high-temperature resistant composite materials and its preparation method. Background Technology

[0002] Epoxy resins are widely used in civil engineering, electronics, aerospace, automotive and mechanical fields due to their excellent mechanical properties, electrical insulation, adhesion, processability and chemical stability. In fiber-reinforced composites, the resin matrix plays a core role in fixing reinforcing fibers, transferring interfacial loads and resisting external environmental erosion. Its performance directly determines the overall mechanical performance and service life of the composite material. With the rapid development of aerospace, high-end equipment manufacturing and other fields, the performance requirements of composite materials in high-temperature environments are becoming increasingly stringent.

[0003] However, the inherent cross-linked network structure of epoxy resin presents a "seesaw" problem, making it difficult to balance heat resistance and toughness. Under high-temperature conditions, the coefficient of thermal expansion of epoxy resin is much greater than that of reinforcing fibers such as carbon fiber, resulting in significant thermal mismatch stress at the interface. This can easily lead to matrix cracking and interface debonding. When the temperature approaches or exceeds the glass transition temperature, the modulus and strength of the resin matrix will drop sharply, and the load-bearing capacity will decrease significantly. During long-term high-temperature service, microcracks will also be generated inside the resin matrix due to thermo-oxidative aging and stress concentration. The stress concentration effect at the crack tip will accelerate crack propagation, seriously affecting load transfer efficiency and ultimately causing macroscopic failure of the material. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a high-toughness resin for high-temperature resistant and high-toughness composite materials and its preparation method.

[0005] To achieve the above objectives, the present invention provides a high-toughness resin for high-temperature resistant composite materials, which is composed of the following raw materials in parts by weight: 60-80 parts of bifunctional epoxy resin; 30-50 parts of polyfunctional resin; Toughening component 20-40 parts; 15-40 parts of curing agent; Diluent 5-20 parts; Accelerator 0.5-2 parts; The bifunctional epoxy resin is selected from one of the following: bisphenol A type epoxy resin, bisphenol F type epoxy resin, polyphenol type glycidyl ether epoxy resin, aliphatic glycidyl ether epoxy resin, and glycidyl ester type epoxy resin. The toughening component is selected from one or more of polyethersulfone, acrylate-modified epoxy resin, polyetheretherketone, polyurethane-modified epoxy resin, polycarbonate, carboxyl-terminated butadiene-acrylonitrile rubber-modified epoxy resin, polyimide, and silicone-modified epoxy resin.

[0006] Furthermore, the polyfunctional resin is selected from one or more of 428 resin, AG-80 resin, 354 resin, TDE-85 resin and BPNE-270 resin.

[0007] Furthermore, the curing agent is selected from diethyltoluenediamine and polyetheramine.

[0008] Furthermore, the diluent is selected from one or more of ethylene glycol diglycidyl ether, trimethylolpropane triglycidyl ether, and benzyl glycidyl ether.

[0009] Furthermore, the accelerator is selected from one or more of DMP-30, triethanolamine, resorcinol, 2-ethylimidazole, and boron trifluoride complex.

[0010] The advantages of the above technical solution are as follows: It uses a bifunctional epoxy resin as the main component, compounded with 30-50 parts of a multifunctional epoxy resin, and introduces 20-40 parts of a polymer toughening component. Simultaneously, appropriate amounts of diluent and accelerator are added. The multifunctional resin increases the crosslinking density to enhance heat resistance, while the interpenetrating network formed by the polymer toughening component or the introduced flexible segments effectively dissipate impact energy. This achieves a significant increase in the glass transition temperature while maintaining the resin's excellent toughness, synergistically improving mechanical properties at high temperatures and avoiding the inherent brittleness of pure multifunctional matrices. Furthermore, the resin system of this invention exhibits good interfacial bonding with various engineering fibers such as carbon fiber, glass fiber, aramid, and PBO fiber, with an interfacial shear strength reaching up to 31.34 MPa. It can efficiently transfer interfacial loads and can be used to manufacture composite materials with high dimensional stability and high precision at high temperatures.

[0011] This invention provides a method for preparing a high-toughness resin for high-temperature resistant composite materials, characterized by comprising the following steps: Step 1: Pretreatment of toughening components: Stir the toughening components at 100℃~180℃ and 200r / min~500r / min for 15min~30min, and then sonicate for 2min~5min. Step 2: Premixing of multifunctional resin: Stir the multifunctional resin at 50℃~100℃ and 200r / min~500r / min for 15min~30min until completely mixed; Step 3, One-step mixing and curing: The pretreated toughening component, the premixed multifunctional resin, the bifunctional main epoxy resin, the curing agent, the diluent, and the accelerator are stirred at 60℃~100℃ and 100r / min~300r / min for 10min~25min. After mixing evenly, vacuum degassing is performed for 5min~10min, and then curing is carried out to obtain a high-toughness resin for high-temperature resistant composite materials.

[0012] Furthermore, the curing process described in step three is as follows: curing at 120℃~180℃ for 2h~4h.

[0013] The advantages of the above technical solution are as follows: the three-step process of toughening component pretreatment, multifunctional resin premixing, and one-step mixing and curing eliminates the need for preparing specially modified nano-toughening particles and using complex phase transfer dispersion processes, as well as the need to control the precise particle size and ratio of toughening particles. It also avoids the cumbersome process problems associated with multi-step phase separation mixing. Specifically, the toughening component undergoes pretreatment at 100℃~180℃ with heating and stirring combined with ultrasonication, which effectively improves its dispersibility in the epoxy resin matrix and avoids performance fluctuations caused by toughening agent agglomeration. Multifunctional resin premixing ensures the full fusion of resins with different functionalities, laying a good foundation for subsequent one-step mixing. The third step uses low-temperature short-time stirring at 60℃~100℃, requiring only 10min~25min, significantly improving production efficiency and reducing energy consumption. Simultaneously, 5min~10min of vacuum degassing effectively eliminates internal air bubbles in the resin, ensuring the density and mechanical properties of the final product. Attached Figure Description

[0014] Figure 1 This is a flowchart of an embodiment of the present invention; Figure 2 This is a view of the glass transition temperature test in Embodiment 1 of the present invention; Figure 3 This is a view of the glass transition temperature test in Embodiment 2 of the present invention; Figure 4 This is a test view of the glass transition temperature in Embodiment 3 of the present invention; Figure 5 A view of the glass transition temperature test of Comparative Example 1; Figure 6 View of glass transition temperature test for Comparative Example 2; Figure 7 View of glass transition temperature test for Comparative Example 3; Detailed Implementation

[0015] Example 1 of the high-toughness resin for high-temperature resistant composite materials of the present invention and its preparation method is as follows: Figure 1-2 As shown: Proportion (parts by weight): Main epoxy resin: Bisphenol A type epoxy resin, 70 parts by weight; Multifunctional resins: 20 parts each of 428 resin and AG-80 resin were selected; Curing agent: Diethyltoluene diamine, 30 parts by weight, is selected as the curing agent; Toughening component: Polyurethane modified epoxy resin, 30 parts by weight; Accelerator: 2-ethylimidazole, 0.5 parts by weight; Diluent: 10 parts by weight of ethylene glycol diglycidyl ether; Its mechanical properties are shown in Table 1 below.

[0016] Its preparation process includes the following steps: Step 1: Stir the polyurethane-modified epoxy resin evenly, heat it to 60℃, rotate it at 250r / min, stir for 5min, and then sonicate it for 2min.

[0017] Step 2: Weigh 428 resin and AG-80 resin, and heat and stir at 100℃ for 10 minutes.

[0018] Step 3: Stir the bisphenol A epoxy resin, multifunctional resin, toughening component, curing agent, accelerator and diluent at 70°C for 30 minutes, controlling the speed at 400 r / min. After thorough mixing, remove air bubbles for 10 minutes, and then cure.

[0019] Example 2 of the high-toughness resin for high-temperature resistant composite materials of the present invention and its preparation method is as follows: Figure 3 As shown: Proportion (parts by weight): Main epoxy resin: Bisphenol A type epoxy resin, 80 parts by weight; Multifunctional resins: BPNE-270 resin and AG-80 resin, 20 parts by weight each; Curing agent: Diethyltoluene diamine, 27 parts by weight; Toughening component: Polyurethane modified epoxy resin, 30 parts by weight; Accelerator: 2-ethylimidazole, 1 part by weight; Diluent: Trimethylolpropane triglycidyl ether, 15 parts by weight; Its mechanical properties are shown in Table 1 below.

[0020] Its preparation process includes the following steps: Step 1: Mix the polyurethane-modified epoxy resin evenly, heat to 60℃, rotate at 250r / min, stir for 5min, and then sonicate for 2min.

[0021] Step 2: Weigh BPNE-270 resin and AG-80 resin, and heat and stir at 80℃ for 10 minutes.

[0022] Step 3: Stir the bisphenol A epoxy resin, multifunctional resin, toughening component, curing agent, accelerator and diluent at 60°C for 30 minutes, controlling the speed at 400 r / min. After thorough mixing, remove air bubbles for 10 minutes, and then cure.

[0023] Example 3 of the high-toughness resin for high-temperature resistant composite materials of the present invention and its preparation method is as follows: Figure 4 As shown: Proportion (parts by weight): Main epoxy resin: Bisphenol F type epoxy resin, 70 parts by weight; Multifunctional resins: 354 resin and 428 resin, 15 parts each by weight; Curing agent: Polyetheramine, 25 parts by weight; Toughening component: Polyurethane modified epoxy resin, 25 parts by weight; Accelerator: Resorcinol, 1 part by weight; Diluent: 10 parts by weight of ethylene glycol diglycidyl ether; Its mechanical properties are shown in Table 1 below.

[0024] Preparation process: Step 1: Stir the polyurethane-modified epoxy resin evenly, heat to 70℃, rotate at 300r / min, stir for 5min, and then sonicate for 2min.

[0025] Step 2: Weigh out 428 resin and 354 resin, and heat and stir at 80℃ for 10 minutes.

[0026] Step 4: Stir the bisphenol F epoxy resin, multifunctional resin, toughening component, curing agent, diluent and accelerator at 70°C for 30 minutes, controlling the speed at 400 r / min. After thorough mixing, remove air bubbles for 20 minutes, and then cure.

[0027] This application also provides a comparative example 1 for reference and comparison, such as... Figure 5 As shown: Proportion (parts by weight): Main epoxy resin: Bisphenol A type epoxy resin, 100 parts by weight; Multifunctional resins: Not added; Curing agent: Diethyltoluene diamine, 30 parts by weight; Toughening components: None added; Accelerator: 2-ethylimidazole, 0.5 parts by weight; Diluent: 10 parts by weight of ethylene glycol diglycidyl ether; Its mechanical properties are shown in Table 1 below.

[0028] Its preparation includes the following steps: Bisphenol A type epoxy resin, curing agent, diluent and accelerator are stirred at 70℃ for 30 min, with the speed controlled at 400 r / min. After thorough mixing, air bubbles are removed for 10 min, and then curing is carried out.

[0029] This application also provides a comparative example 2 for reference and comparison, such as... Figure 6 As shown: Proportion (parts by weight): Main epoxy resin: Bisphenol A type epoxy resin, 100 parts by weight; Multifunctional resins: 20 parts each of 428 resin and AG-80 resin were selected; Curing agent: Diethyltoluene diamine, 30 parts by weight, is selected as the curing agent; Toughening components: None added; Accelerator: 2-ethylimidazole, 0.5 parts by weight; Diluent: 10 parts by weight of ethylene glycol diglycidyl ether; Its mechanical properties are shown in Table 1 below.

[0030] Its preparation includes the following steps: Step 1: Weigh 428 resin and AG-80 resin, and heat and stir at 100℃ for 10 minutes.

[0031] Step 2: Stir the bisphenol A epoxy resin, curing agent, diluent and accelerator at 70°C for 30 minutes, controlling the speed to 400 r / min. After thorough mixing, remove air bubbles for 10 minutes, and then cure.

[0032] The mechanical properties of the above resins are shown in Table 1.

[0033] This application also includes a comparative example 3 for reference and comparison, such as... Figure 7 As shown: Proportion (parts by weight): Main epoxy resin: Bisphenol A type epoxy resin, 70 parts by weight; Multifunctional resins: Not added; Curing agent: Diethyltoluene diamine, 30 parts by weight; Toughening component: Polyurethane modified epoxy resin, 30 parts by weight; Accelerator: 2-ethylimidazole, 0.5 parts by weight; Diluent: 10 parts by weight of ethylene glycol diglycidyl ether; Preparation process: Step 1: Stir the polyurethane-modified epoxy resin evenly, heat to 60℃, rotate at 250r / min, stir for 5min, and then sonicate for 2min.

[0034] Step 2: Stir the bisphenol A epoxy resin with the curing agent, toughening component, diluent and accelerator at 70°C for 30 minutes, controlling the speed at 400 r / min. After thorough mixing, remove air bubbles for 10 minutes, and then cure.

[0035] The mechanical properties of the above resins are shown in Table 1.

[0036] Table 1 Mechanical properties of several resin systems (25℃)

[0037] As can be seen from the data in Table 1, Comparative Example 1 had the worst performance because it did not contain either toughening components or polyfunctional resins. Comparative Example 2 contained polyfunctional resins but no toughening components, while Comparative Example 3 contained toughening components but no polyfunctional resins. Both groups showed some improvement in the mechanical properties of the resins. Example 1 had the best mechanical properties, indicating that the two components could play a synergistic modifying role.

[0038] The above examples are merely one preferred embodiment of the present invention. Ordinary variations and substitutions made by those skilled in the art within the scope of the technical solution of the present invention are all included within the protection scope of the present invention.

Claims

1. A high-toughness resin for high-temperature resistant composite materials, characterized in that, From the following parts by weight of raw materials composition: 60-80 parts of bifunctional epoxy resin; 30-50 parts of polyfunctional resin; Toughening component 20-40 parts; 15-40 parts of curing agent; 5-20 parts diluent; Accelerator 0.5-2 parts; The bifunctional epoxy resin is selected from one of the following: bisphenol A type epoxy resin, bisphenol F type epoxy resin, polyphenol type glycidyl ether epoxy resin, aliphatic glycidyl ether epoxy resin, and glycidyl ester type epoxy resin. The toughening component is selected from one or more of polyethersulfone, acrylate-modified epoxy resin, polyetheretherketone, polyurethane-modified epoxy resin, polycarbonate, carboxyl-terminated butadiene-acrylonitrile rubber-modified epoxy resin, polyimide, and silicone-modified epoxy resin.

2. The high-toughness resin for high-temperature resistant composite materials according to claim 1, characterized in that: The polyfunctional resin is selected from one or more of 428 resin, AG-80 resin, 354 resin, TDE-85 resin and BPNE-270 resin.

3. The high-toughness resin for high-temperature resistant composite materials according to claim 1, characterized in that: The curing agent is selected from diethyltoluenediamine and polyetheramine.

4. The high-toughness resin for high-temperature resistant composite materials according to claim 1, characterized in that: The diluent is selected from one or more of ethylene glycol diglycidyl ether, trimethylolpropane triglycidyl ether, and benzyl glycidyl ether.

5. The high-toughness resin for high-temperature resistant composite materials according to claim 1, characterized in that: The accelerator is selected from one or more of DMP-30, triethanolamine, resorcinol, 2-ethylimidazole, and boron trifluoride complex.

6. A method for preparing a high-toughness resin for high-temperature resistant composite materials as described in any one of claims 1-5, characterized in that, Includes the following steps: (1) Pretreatment of toughening components: Stir the toughening components at 100℃~180℃ and 200r / min~500r / min for 15min~30min, and then sonicate for 2min~5min; (2) Premixing of multifunctional resin: Stir the multifunctional resin at 50℃~100℃ and 200r / min~500r / min for 15min~30min until completely mixed; (3) One-step mixing and curing: The pretreated toughening component, the premixed multifunctional resin, the bifunctional main epoxy resin, the curing agent, the diluent, and the accelerator are stirred at 60℃~100℃ and 100r / min~300r / min for 10min~25min. After mixing evenly, vacuum degassing is performed for 5min~10min, and then curing is carried out to obtain a high-toughness resin for high-temperature resistant composite materials.

7. The preparation method according to claim 6, characterized in that, The curing process described in step (3) is: curing at 120℃~180℃ for 2h~4h.

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