A high-strength, large-deformation shape memory epoxy resin system and its preparation technology

Abstract

This invention discloses a high-strength, large-deformation shape memory epoxy resin system and its preparation technology. Addressing the problems of poor strength, processability, and dispersibility inherent in traditional thermoplastic-modified epoxy resin systems, this invention prepares SiO2 / CE-modified PPO (SiO2 / CE@PPO) particles using hydroxyl-terminated polyphenylene ether (PPO), cyanate ester resin (CE), and fumed silica (SiO2). Compared to pure epoxy resin systems and traditional thermoplastic-modified epoxy resin systems, the SiO2 / CE@PPO particle-modified epoxy material system prepared in this invention not only significantly improves mechanical strength, impact strength, and glass transition temperature, but also exhibits a more uniform phase structure and stable processability. Furthermore, the product of this invention possesses excellent complex large-deformation and shape memory behavior, making this epoxy resin system applicable to aerospace, electronics, and automotive fields.

Description

Technical Field

[0001] This invention belongs to the field of high-performance epoxy resins, specifically relating to a high-strength, large-deformation shape memory epoxy resin system and its preparation technology. Background Technology

[0002] Epoxy resins have wide applications in aerospace, electronics, automobiles, construction and other fields. As a thermosetting epoxy resin, it often exhibits low impact resistance due to its high crosslinking density, and is therefore prone to cracking and other damage during use. Toughening thermosetting resins with thermoplastic components is a traditional toughening technique. However, under the condition of effectively toughening thermosetting resins, the introduction of thermoplastic components often brings the following drawbacks: (1) Although using low molecular weight thermoplastic components can better maintain the processability of thermosetting components, it will significantly reduce the heat resistance and strength of the thermosetting resin system; (2) Although using high molecular weight thermoplastic components can better maintain the thermal properties of thermosetting resins, it will seriously affect the processability of thermosetting resins, and the phase separation structure is uneven, which makes the performance stability of thermosetting resins worse. Therefore, based on the traditional thermoplastic toughening thermosetting resin system, it is of great significance to achieve effective toughening of thermosetting epoxy resins while retaining and improving the original excellent mechanical and thermal properties of the thermosetting resin system. Furthermore, with the increasing complexity of application environments for epoxy resin materials and their expansion into smart materials applications, developing epoxy resin systems with excellent large deformation shape memory behavior is of great significance. Traditional thermosetting resins struggle to exhibit large deformation and complex shape memory behavior when the sample is thick because thicker samples have a large deformation limit, low elastic modulus, and low tensile strength, making them relatively difficult to deform. Therefore, improving the large deformation and complex deformation capabilities of epoxy resin systems is of particular importance. Summary of the Invention

[0003] Given the current problems of insufficient mechanical strength and toughness, and deteriorated heat resistance and processability stability of thermoplastic modified thermosetting epoxy resins, this invention prepares hydroxyl-terminated polyphenylene ether (PPO) particles modified with fumed SiO2 and cyanate ester CE resin to modify epoxy resins. This is used to improve the toughness, strength, and heat resistance of epoxy resins, maintain the processability of the resin system, improve the deformation capacity of epoxy resins, and realize the large deformation and complex shape memory behavior of epoxy resin systems.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows.

[0005] A method for preparing a high-strength, large-deformation shape memory epoxy resin system includes the following steps:

[0006] (1) Hydroxyl-terminated polyphenylene oxide (PPO) is heated and reacted with cyanate ester (CE) resin, then silica (SiO2) is added and the reaction continues. Then it is mixed with polyvinyl alcohol solution and reacted again to obtain SiO2-CE modified PPO (SiO2-CE@PPO) particles.

[0007] (2) Add SiO2-CE modified PPO to epoxy resin and mix and react, then add catalyst and acid anhydride, and prepolymerize to obtain prepolymer; or add SiO2-CE modified PPO to epoxy resin and mix and react, then add catalyst, accelerator and acid anhydride, and prepolymerize to obtain prepolymer.

[0008] (3) The prepolymer is cured to obtain a high-strength, large-deformation shape memory epoxy resin system.

[0009] A method for preparing a prepolymer for a high-strength, large-deformation shape memory epoxy resin system includes the following steps:

[0010] (1) Hydroxyl-terminated polyphenylene oxide (PPO) is heated and reacted with cyanate ester (CE) resin, then silica (SiO2) is added and the reaction continues. Then it is mixed with polyvinyl alcohol solution and reacted again to obtain SiO2-CE modified PPO.

[0011] (2) Add SiO2-CE modified PPO to epoxy resin and mix and react, then add catalyst and acid anhydride, and prepolymerize to obtain prepolymer; or add SiO2-CE modified PPO to epoxy resin and mix and react, then add catalyst, accelerator and acid anhydride, and prepolymerize to obtain prepolymer.

[0012] In this invention, in step (1), the heating reaction temperature is 100-120℃ and the time is 2-4h; the reaction temperature is 100-120℃ and the time is 1-4h; the reaction is carried out again at 60-90℃ for 0.5-4h, and then at room temperature for 5-10h; in step (2), the mixing reaction temperature is 100-150℃ and the time is 10-30min; the prepolymerization reaction temperature is 100-150℃ and the time is 0.5-2h.

[0013] In this invention, the mass ratio of hydroxyl-terminated polyphenylene ether, cyanate resin, silica, and polyvinyl alcohol solution is (10-20):(1-5):(1-3):(100-300); the mass ratio of epoxy resin, SiO2-CE modified PPO particles, acid anhydride, catalyst, and accelerator is 100:(10-45):(25-50):(0.1~3):(0-10).

[0014] In this invention, the number average molecular weight of the hydroxyl-terminated polyphenylene ether is 1100-3000.

[0015] In this invention, the cyanate resin is a bisphenol A type cyanate resin and its derivatives.

[0016] In this invention, the particle size of silica is 7-40 nanometers; preferably, the silica is fumed silica, which is a reaction product of dimethyl (siloxane and polysiloxane) and silica.

[0017] In this invention, the epoxy resin includes one or more of the following: glycidyl ether type epoxy resin (such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenolic type epoxy resin), glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, alicyclic epoxy resin, and linear aliphatic epoxy compound.

[0018] In this invention, the acid anhydride is an acid anhydride with a melting point below 130°C; including one or more of glutaric anhydride, maleic anhydride, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and methylnadic anhydride.

[0019] In this invention, the catalyst includes organometallic compounds.

[0020] In this invention, the accelerator includes tertiary amine organic compounds.

[0021] In this invention, curing is performed at 130-200℃ for 4-6 hours.

[0022] This invention discloses a high-strength, high-deformation shape memory epoxy resin system or a prepolymer for a high-strength, high-deformation shape memory epoxy resin system prepared according to the above preparation method.

[0023] This invention discloses the application of the above-mentioned high-strength, large-deformation shape memory epoxy resin system or the prepolymer of the high-strength, large-deformation shape memory epoxy resin system in the preparation of epoxy resin materials.

[0024] This invention discloses an epoxy resin material, wherein the raw materials for preparing the epoxy resin material include a high-strength, high-deformation, shape-memory epoxy resin system or a prepolymer for a high-strength, high-deformation, shape-memory epoxy resin system.

[0025] In this invention, the epoxy resin material has large deformation and complex shape memory properties.

[0026] Compared with existing technologies, the beneficial effects of this invention are as follows: the SiO2 / CE@PPO particle-modified epoxy material system prepared by this invention not only significantly improves mechanical strength, impact strength, and glass transition temperature, but also has a more uniform phase structure and stable processing performance. Furthermore, the prepared samples, when they have a certain thickness, such as 4-6 mm, also exhibit excellent large deformation and complex shape memory behavior. Attached Figure Description

[0027] Figure 1 The images are SEM images of SiO2-CE@PPO particles, where (a) is a SiO2-CE@PPO particle, (b) is a magnified SiO2-CE@PPO particle, (c) is the surface of a SiO2-CE@PPO particle, and (d) is a broken SiO2-CE@PPO particle.

[0028] Figure 2 The images show the Fourier Transform Infrared (FTIR) spectra of PPO, CE, SiO2, PPO-CE, and SiO2-CE@PPO particles, where (a) is the full FTIR spectrum and (b) is the narrow spectrum of PPO, CE, and PPO-CE.

[0029] Figure 3 The images shown are SEM images of the fracture surfaces of the samples. (a) is the epoxy material sample of Example 1, (a′) is the SiO2-CE@PPO particles in the sample of Example 1, (b) is Comparative Example 1-1, (c) is Comparative Example 1-2, (d) is Comparative Example 1-3, (e) is Comparative Example 1-4, (f) is Comparative Example 1-5, (g) is Comparative Example 1-6, (h) is Comparative Example 1-7, and (i) is Comparative Example 1-8.

[0030] Figure 4 Images show the deformation and shape memory behavior of the samples, where (a) is Example 1, (b) is Comparative Example 1-1, and (c) is Comparative Example 1-2.

[0031] Figure 5 Images showing the deformation and shape memory behavior of the sample in Example 2.

[0032] Figure 6 Images showing the deformation and shape memory behavior of the sample in Example 3.

[0033] Figure 7 For product characterization, (a) is an optical microscope image of SiO2-CE@PPO particles in Example 4, (b) is a SEM image of SiO2-CE@PPO particles, and (c) is a SEM image of the CE-PPO surface.

[0034] Figure 8 Images showing the deformation and shape memory behavior of the sample in Example 4. Detailed Implementation

[0035] This invention discloses a high-strength, high-deformation shape memory epoxy resin system or a prepolymer for a high-strength, high-deformation shape memory epoxy resin system, the preparation process of which is as follows:

[0036] (1) Hydroxyl-terminated polyphenylene oxide (PPO) was dissolved in toluene at 80-100℃, and then cyanate ester (CE) resin was added. The reaction was carried out at 100-120℃ for 2-4 hours. Then, fumed nano-SiO2 was added, and the reaction was continued with stirring for 1-4 hours. Subsequently, it was added to a polyvinyl alcohol aqueous solution (mass concentration of 1-3%) at 60-90℃ and stirred for 0.5-4 hours. Then, the stirring was continued at room temperature for 5-10 hours. The suspension was then washed with deionized water 5-6 times and then washed with acetone 2-4 times to obtain SiO2-C. E-modified PPO (SiO2-CE@PPO) particles, wherein the mass ratio of hydroxyl-terminated polyphenylene ether PPO, CE, SiO2, toluene, and polyvinyl alcohol solution is (10-20):(1-5):(1-3):(30-50):(100-300); preferably, the mass ratio of hydroxyl-terminated polyphenylene ether PPO, CE, SiO2, toluene, and polyvinyl alcohol solution is (10-15):(1-3):(1-3):(40-50):(100-200).

[0037] (2) SiO2-CE@PPO particles are added to epoxy resin at room temperature, and then stirred at 100-150℃ for 10-30 min. Catalyst / accelerator and acid anhydride are added, and the mixture is heated and stirred at 100-150℃ for 0.5-2 h to obtain a prepolymer for a high-strength, large-deformation shape memory epoxy resin system. After vacuum degassing at 80-100℃, the prepolymer is injected into a mold and then cured at 130-200℃ for 4-6 h according to the temperature program to obtain an epoxy resin material system. The mass ratio of epoxy resin (EP), SiO2-CE@PPO particles, acid anhydride, catalyst, and accelerator is 100:(10-45):(25-50):(0.1-3):(0-10). Preferably, the mass ratio of epoxy resin (EP), SiO2-CE@PPO particles, acid anhydride, catalyst, and accelerator is 100:(10-25):(25-40). ∶(0.1-1)∶(0.05-1)。

[0038] In the above technical solution, the cyanate resin is bisphenol A type cyanate resin and its derivatives.

[0039] In the above technical solution, the gas-phase nano-SiO2 has an average particle size of 7-40 nanometers and is a reaction product of dimethyl (siloxane and polysiloxane) and silicon dioxide, such as CAS number 67762-90-7.

[0040] In the above technical solution, the epoxy resin includes one or more of the following: glycidyl ether type epoxy resin (such as: bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenolic type epoxy resin), glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, alicyclic epoxy resin, and linear aliphatic epoxy compound.

[0041] In the above technical solutions, the acid anhydride is an acid anhydride with a melting point below 130℃, including glutaric anhydride, maleic anhydride, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, etc.

[0042] In the above technical solutions, the catalyst is an organometallic compound, such as zinc naphthenate, zinc octanoate, manganese octanoate, zinc acetylacetonate, dibutyltin dilaurate, zinc acetate, manganese acetylacetonate, calcium acetate, magnesium acetate, etc. The accelerator is a tertiary amine compound, such as pyridine, triethylamine, triethanolamine, N-dimethylbenzylamine, 2,4,6-tris(dimethylaminomethyl)phenol, etc.

[0043] The epoxy resin system prepared by this invention has high mechanical properties (flexural strength: ~145MPa; impact strength: ~59kJ / m). 2 It has excellent thermal properties (glass transition temperature: ~136℃), process stability, and excellent deformation and shape memory properties.

[0044] The following specific experiments illustrate the technological advancements of this invention. The raw materials used are existing products, and the specific preparation operations and performance tests are conventional techniques. Specifically, the hydroxyl-terminated polyphenylene oxide (PPO) has a number-average molecular weight of 1100, the average particle size of the fumed nano-SiO2 is 20 nm, and the number-average molecular weight of polyvinyl alcohol (PVA) is 63800.

[0045] Performance testing is a standard technique, briefly described below:

[0046] Mechanical properties were tested according to national standard GB / T 2567-2021, with glass transition temperature T... g The DMA method was used, with a heating rate of 3℃ / min and a frequency of 1Hz, and nitrogen was used.

[0047] The viscosity of the resin system (excluding acid anhydrides, catalysts, and accelerators) was tested using a rotational viscometer.

[0048] The morphology of the samples was analyzed using scanning electron microscopy and optical microscopy.

[0049] The deformation and shape memory of the sample are achieved by heating the sample to T. g After reaching +20℃, an external force is applied to deform it, then it is rapidly cooled to room temperature to fix its shape, and then the sample is heated to T. g The shape is restored at +20℃; the thickness of the deformed and shape memory samples is controlled at 4-4.5mm, the width at 5-6mm, and the length at 7-8cm. Example 1

[0050] (1) Preparation of SiO2 / CE modified PPO (SiO2-CE@PPO) particles:

[0051] In a closed three-necked flask reactor equipped with a condenser, hydroxyl-terminated polyphenylene ether (PPO, number average molecular weight 1100) was dissolved in toluene at 80°C, and then bisphenol A cyanate ester resin (CE) was added. The reaction was carried out at 100°C for 2 hours, followed by the addition of fumed nano-SiO2. The reaction was continued with stirring for 1 hour, and then added to a 1% (w / w) aqueous solution of polyvinyl alcohol (PVA) at 80°C. The mixture was stirred (900 rpm) for 2 hours, and then stirred at room temperature for another 6 hours. The suspension was then washed five times with deionized water and twice with acetone to obtain SiO2-CE modified PPO (SiO2-CE@PPO) particles. The mass ratio of hydroxyl-terminated polyphenylene ether PPO, CE, SiO2, toluene, and polyvinyl alcohol solution was 10:1:3:50:100.

[0052] Figure 1 These are SEM images of SiO2-CE@PPO particles, from... Figure 1 As can be seen from (a) and (b), the particle size of SiO2-CE@PPO particles is 1-6 micrometers. Figure 1 As can be seen in (c), the surface of the SiO2-CE@PPO particles has a large number of SiO2 nanoparticles. Figure 1 As can be seen from the fractured SiO2-CE@PPO particles in (d), the surface of the SiO2-CE@PPO particles also contains SiO2-CE@PPO particles.

[0053] Figure 2 These are the FTIR spectra of PPO, CE, SiO2, PPO-CE, and SiO2-CE@PPO particles. By comparing the FTIR spectra of PPO and CE, where (a) is the full FTIR spectrum and (b) is the narrow spectrum, it can be found that after PPO and CE react at 100℃ for 2 hours, the -OH peak (3570-3210 cm⁻¹) in the PPO-CE system... -1 -OCN peaks (2276 and 2237 cm⁻¹) -1 The intensity decreased significantly at 1560cm. -1 (-N=CO-) and 1540cm -1 The enhanced absorption peak at (C=O) indicates a reaction between the -OCN in CE and the -OH in PPO. Comparing the FTIR spectra of the PPO-CE system and SiO2, it can be found that the absorption peak at 1075 cm⁻¹ in the FTIR spectrum of SiO2-CE@PPO particles is more pronounced. -1 The absorption peak at that point is enhanced, which is mainly due to the Si-O bond.

[0054] Combination Figure 1 and Figure 2 This confirms the successful preparation of SiO2-CE@PPO particles.

[0055] (2) Preparation of epoxy composite materials:

[0056] SiO2-CE@PPO particles were added to bisphenol A type epoxy resin E51 at room temperature. After stirring at 120℃ for 30 min, zinc acetylacetonate catalyst, triethylamine accelerator, and glutaric anhydride were added. The mixture was heated and stirred at 130℃ for 1 h to obtain a prepolymer. After vacuum degassing at 100℃, the prepolymer was injected into a conventional mold and then cured according to the temperature program 150℃ / 2h + 180℃ / 2h + 200℃ / 2h to obtain an epoxy resin composite material system. The mass ratio of epoxy resin (EP), SiO2-CE@PPO particles, glutaric anhydride, catalyst, and accelerator was 100:14:30:0.5:0.1.

[0057] Comparative Example 1-1

[0058] Bisphenol A type epoxy resin E51 was stirred at 120℃ for 30 min, and then zinc acetylacetonate catalyst, triethylamine accelerator, and glutaric anhydride were added. The mixture was heated and stirred at 130℃ for 1 h, and after vacuum degassing at 100℃, it was injected into a mold and then cured according to the temperature program of 150℃ / 2 h + 180℃ / 2 h + 200℃ / 2 h to obtain an epoxy resin composite material system. The mass ratio of epoxy resin (EP), glutaric anhydride, catalyst, and accelerator was 100:30:0.5:0.1.

[0059] Comparative Examples 1-2

[0060] Hydroxyl-terminated polyphenylene oxide (PPO, number average molecular weight 1100) particles were added to epoxy resin E51 at room temperature. After stirring at 120°C for 30 min, zinc acetylacetonate catalyst, triethylamine accelerator, and glutaric anhydride were added. The mixture was heated and stirred at 130°C for 1 h. After vacuum degassing at 100°C, the mixture was injected into a mold and then cured according to the temperature program 150°C / 2 h + 180°C / 2 h + 200°C / 2 h to obtain an epoxy resin composite material system. The mass ratio of epoxy resin (EP), PPO particles, glutaric anhydride, catalyst, and accelerator was 100:10:30:0.5:0.1.

[0061] Comparative Examples 1-3

[0062] Bisphenol A type cyanate resin CE was added to bisphenol A type epoxy resin E51 at room temperature. After stirring at 120℃ for 30 min, zinc acetylacetonate catalyst, triethylamine accelerator, and glutaric anhydride were added. The mixture was heated and stirred at 130℃ for 1 h. After vacuum degassing at 100℃, the mixture was injected into a mold and then cured according to the temperature program 150℃ / 2 h + 180℃ / 2 h + 200℃ / 2 h to obtain an epoxy resin composite material system. The mass ratio of epoxy resin (EP), CE, anhydride, catalyst, and accelerator was 100:1:30:0.5:0.1.

[0063] Comparative Examples 1-4

[0064] At room temperature, fumed nano-SiO2 particles were added to bisphenol A type epoxy resin E51. After stirring at 120℃ for 30 min, zinc acetylacetonate catalyst, triethylamine accelerator, and glutaric anhydride were added. The mixture was heated and stirred at 130℃ for 1 h. After vacuum degassing at 100℃, the mixture was injected into a mold and then cured according to the temperature program 150℃ / 2 h + 180℃ / 2 h + 200℃ / 2 h to obtain an epoxy resin composite material system. The mass ratio of epoxy resin (EP), SiO2 particles, anhydride, catalyst, and accelerator was 100:3:30:0.5:0.1.

[0065] Comparative Examples 1-5

[0066] At room temperature, fumed nano-SiO2 particles, bisphenol A type cyanate CE resin, and hydroxyl-terminated polyphenylene ether (PPO) particles were added to bisphenol A type epoxy resin E51. After stirring at 120℃ for 30 min, zinc acetylacetonate catalyst, triethylamine accelerator, and glutaric anhydride were added. The mixture was heated and stirred at 130℃ for 1 h. After vacuum degassing at 100℃, the mixture was injected into a mold and then cured according to the temperature program 150℃ / 2 h + 180℃ / 2 h + 200℃ / 2 h to obtain an epoxy resin composite material system. The mass ratio of epoxy resin (EP), SiO2, CE, PPO particles, anhydride, catalyst, and accelerator was 100:3:1:10:30:0.5:0.1.

[0067] Comparative Examples 1-6

[0068] At room temperature, fumed nano-SiO2 particles and bisphenol A cyanate CE resin were added to bisphenol A epoxy resin E51. After stirring at 120°C for 30 min, zinc acetylacetonate catalyst, triethylamine accelerator, and glutaric anhydride were added. The mixture was heated and stirred at 130°C for 1 h. After vacuum degassing at 100°C, the mixture was injected into a mold and then cured according to the temperature program 150°C / 2 h + 180°C / 2 h + 200°C / 2 h to obtain an epoxy resin composite material system. The mass ratio of epoxy resin (EP), SiO2, CE, anhydride, catalyst, and accelerator was 100:3:1:30:0.5:0.1.

[0069] Comparative Examples 1-7

[0070] At room temperature, fumed nano-SiO2 particles and hydroxyl-terminated polyphenylene oxide (PPO) particles were added to bisphenol A type epoxy resin E51. After stirring at 120°C for 30 min, zinc acetylacetonate catalyst, triethylamine accelerator, and glutaric anhydride were added. The mixture was heated and stirred at 130°C for 1 h. After vacuum degassing at 100°C, the mixture was injected into a mold and then cured according to the temperature program 150°C / 2 h + 180°C / 2 h + 200°C / 2 h to obtain an epoxy resin composite material system. The mass ratio of epoxy resin (EP), SiO2, PPO particles, anhydride, catalyst, and accelerator was 100:3:10:30:0.5:0.1.

[0071] Comparative Examples 1-8

[0072] Bisphenol A type cyanate resin CE and hydroxyl-terminated polyphenylene ether particles were added to bisphenol A type epoxy resin E51 at room temperature. After stirring at 120°C for 30 min, zinc acetylacetonate catalyst, triethylamine accelerator, and glutaric anhydride were added. The mixture was heated and stirred at 130°C for 1 h. After vacuum degassing at 100°C, the mixture was injected into a mold and then cured according to the temperature program 150°C / 2 h + 180°C / 2 h + 200°C / 2 h to obtain an epoxy resin composite material system. The mass ratio of epoxy resin (EP), CE, PPO particles, anhydride, catalyst, and accelerator was 100:1:10:30:0.5:0.1.

[0073] Table 1 shows the mechanical properties and glass transition temperature (T0) of the epoxy materials in Example 1 and Comparative Examples 1-1 to 1-8. g And viscosity. As can be seen from Table 1, the sample of Example 1 has significantly higher impact strength, flexural strength and glass transition temperature compared with the sample of the comparative example; in addition, the addition of SiO2-CE@PPO particles can maintain the viscosity of the resin system well, that is, maintain the process stability of the resin system.

[0074] Figure 3These are SEM images of the fracture surfaces of epoxy material samples from Example 1 and Comparative Examples 1-1 to 1-8, where (a) is the epoxy material sample from Example 1, (a′) is the SiO2-CE@PPO particles in the sample from Example 1, (b) is Comparative Example 1-1, (c) is Comparative Example 1-2, (d) is Comparative Example 1-3, (e) is Comparative Example 1-4, (f) is Comparative Example 1-5, (g) is Comparative Example 1-6, (h) is Comparative Example 1-7, and (i) is Comparative Example 1-8; from Figure 3 As can be seen in (a), SiO2-CE@PPO can significantly inhibit crack propagation in the EP matrix and is relatively uniformly dispersed in the matrix; from Figure 3 As can be seen from (a′) and (e), the nano-SiO2 particles dispersed in the PPO phase structure can reduce their aggregation in the matrix; the above phenomenon indicates that the addition of SiO2-CE@PPO is beneficial to the improvement of the mechanical properties of the resin matrix.

[0075] Figure 4 These are images depicting the deformation and shape memory behavior of samples from Example 1, Comparative Example 1-1, and Comparative Example 1-2. From... Figure 4 It can be seen that when the sample of Example 1 is heated to T g At +20℃, it can undergo large deformation without fracture under external force, while Comparative Examples 1-1 and 1-2, when heated to T... g It fractured under large deformation caused by external force at +20℃. Surprisingly, the sample in Example 1, after deformation and reheating to T... g It can quickly recover to its initial shape at +20℃, while the samples of Comparative Example 1-1 and Comparative Example 1-2 do not exhibit this complex large deformation and shape memory behavior. The sample of Example 1 not only exhibits complex large deformation behavior under thermal activation conditions, but also has excellent shape memory behavior.

[0076] Table 1. Performance characterization data of epoxy composite materials in Example 1 and Comparative Examples 1-1 to 1-8

[0077] Example 2

[0078] (1) Prepare SiO2 / CE modified PPO (SiO2-CE@PPO) particles according to the steps in Example 1.

[0079] (2) Preparation of epoxy composite materials:

[0080] SiO2-CE@PPO particles were added to bisphenol A type epoxy resin E51 at room temperature. After stirring at 120℃ for 30 min, zinc acetylacetonate catalyst, triethylamine accelerator, and glutaric anhydride were added. The mixture was heated and stirred at 130℃ for 1 h. After vacuum degassing at 100℃, the mixture was injected into a mold and then cured according to the temperature program 150℃ / 2 h + 180℃ / 2 h + 200℃ / 2 h to obtain an epoxy resin composite material system. The mass ratio of epoxy resin (EP), SiO2-CE@PPO particles, anhydride, catalyst, and accelerator was 100:20:30:0.5:0.1.

[0081] The impact strength of the epoxy resin composite system obtained above is 59 kJ / m. 2 The flexural strength was 139 MPa, the glass transition temperature was 103℃, and the viscosity of the epoxy resin system at 120℃ was 125 mPa·s. It had significantly higher impact strength, flexural strength, and glass transition temperature than the sample in Comparative Example 1-1. Moreover, the addition of SiO2-CE@PPO particles to the resin did not significantly change the viscosity of the resin, which means that the addition of SiO2-CE@PPO particles is beneficial to maintaining the resin processability.

[0082] Figure 5 Images showing the deformation and shape memory behavior of the sample in Example 2, when the sample is heated to T. g At +20℃, the sample can undergo complex and large deformations without fracturing under external force, and the sample can be reheated to T after deformation. g It can quickly recover to its initial shape at +20℃. Therefore, the sample in Example 2 not only exhibits complex large deformation behavior under thermal activation conditions, but also possesses excellent shape memory behavior. Example 3

[0083] (1) Prepare SiO2 / CE modified PPO (SiO2-CE@PPO) particles according to the steps in Example 1.

[0084] (2) Preparation of epoxy composite materials:

[0085] SiO2-CE@PPO particles were added to bisphenol A type epoxy resin E51 at room temperature. After stirring at 120℃ for 30 min, zinc acetylacetonate catalyst, triethylamine accelerator, and glutaric anhydride were added. The mixture was heated and stirred at 130℃ for 1 h. After vacuum degassing at 100℃, the mixture was injected into a mold and then cured according to the temperature program 150℃ / 2 h + 180℃ / 2 h + 200℃ / 2 h to obtain an epoxy resin composite material system. The mass ratio of epoxy resin (EP), SiO2-CE@PPO particles, anhydride, catalyst, and accelerator was 100:10:30:0.5:0.1.

[0086] The impact strength of the epoxy resin composite system obtained above is 33 kJ / m. 2 The flexural strength was 118 MPa, the glass transition temperature was 92℃, and the viscosity of the epoxy resin system at 120℃ was 42 mPa•s. It showed significantly higher impact strength, flexural strength, and glass transition temperature than the sample in Comparative Example 1-1. Furthermore, the addition of SiO2-CE@PPO particles to the resin did not significantly change the resin viscosity, which means that the addition of SiO2-CE@PPO particles is beneficial to maintaining the resin processability.

[0087] Figure 6 Images showing the deformation and shape memory behavior of the sample in Example 3, when the sample was heated to T. g At +20℃, the sample can undergo complex and large deformations without fracturing under external force, and the sample can be reheated to T after deformation. g It can quickly recover to its initial shape at +20℃. Therefore, the sample in Example 3 not only exhibits complex large deformation behavior under thermal activation conditions, but also possesses excellent shape memory behavior. Example 4

[0088] (1) Preparation of SiO2 / CE modified PPO (SiO2-CE@PPO) particles:

[0089] In a closed three-necked flask reactor equipped with a condenser, hydroxyl-terminated polyphenylene ether (PPO) (number average molecular weight 2200) was dissolved in toluene at 80°C. Then, bisphenol A cyanate ester (CE) resin was added, and the reaction was carried out at 100°C for 4 hours. Then, fumed nano-SiO2 was added, and the reaction was continued with stirring for 1 hour. After that, it was added to a 2% (w / w) polyvinyl alcohol aqueous solution at 80°C and stirred for 3 hours. Then, the stirring was continued at room temperature for 5 hours. The suspension was then washed 5 times with deionized water and 2 times with acetone to obtain SiO2-CE modified PPO (SiO2-CE@PPO) particles. The mass ratio of hydroxyl-terminated PPO, CE, SiO2, toluene, and polyvinyl alcohol solution was 10:2:2:50:100.

[0090] Figure 7 These are optical microscope images of SiO2-CE@PPO particles, and SEM images of the surfaces of SiO2-CE@PPO particles and CE-PPO products. From... Figure 7 As can be seen in (a), the particle size of SiO2-CE@PPO particles is 5-10 micrometers; from Figure 7 As can be seen in (b), the surface of SiO2-CE@PPO particles has a large number of nanoparticle protrusions, which is significantly larger than that of the CE-PPO product surface. Figure 7 The roughness (c) is due to SiO2 and its aggregates on the surface of SiO2-CE@PPO particles.

[0091] Preparation of CE-PPO product: In a closed three-necked flask reactor equipped with a condenser, hydroxyl-terminated polyphenylene ether (PPO) (number average molecular weight 2200) was dissolved in toluene at 80°C, and then bisphenol A cyanate ester (CE) resin was added. After reacting at 100°C for 4 hours, the product was washed five times with acetone and dried at room temperature to obtain the CE-PPO product; wherein the mass ratio of hydroxyl-terminated polyphenylene ether (PPO), CE, and toluene was 10:2:50.

[0092] (2) Preparation of epoxy composite materials:

[0093] SiO2-CE@PPO particles were added to bisphenol-type epoxy resin E44 at room temperature. After stirring and heating at 120℃ for 30 min, zinc acetylacetonate catalyst, triethylamine accelerator, and methyltetrahydrophthalic anhydride were added. The mixture was heated and stirred at 130℃ for 1 h. After vacuum degassing at 100℃, the mixture was injected into a mold and then cured according to the temperature program 150℃ / 2 h + 180℃ / 2 h + 200℃ / 2 h to obtain an epoxy resin composite material system. The mass ratio of epoxy resin (EP), SiO2-CE@PPO particles, anhydride, catalyst, and accelerator was 100:15:35:0.1:0.5.

[0094] Comparative Example 4

[0095] Bisphenol type epoxy resin E44 was stirred at 120℃ for 30 min, and then zinc acetylacetonate catalyst, triethylamine accelerator, and methyltetrahydrophthalic anhydride were added. The mixture was heated and stirred at 130℃ for 1 h, and after vacuum degassing at 100℃, it was injected into a mold and then cured according to the temperature program of 150℃ / 2 h + 180℃ / 2 h + 200℃ / 2 h to obtain an epoxy resin composite material system. The mass ratio of epoxy resin (EP), anhydride, catalyst, and accelerator was 100:35:0.5:0.1.

[0096] Table 2 shows the mechanical properties, glass transition temperature, and resin system viscosity of the epoxy materials in Example 4 and Comparative Example 4. As can be seen from Table 2, the sample in Example 4 exhibits significantly higher impact strength, flexural strength, and glass transition temperature than the sample in Comparative Example 4. Furthermore, the addition of SiO2-CE@PPO particles to the resin does not significantly alter the resin viscosity, indicating that the addition of SiO2-CE@PPO particles is beneficial for maintaining the resin's processability. Figure 8 Images of the deformation and shape memory behavior of the sample in Example 4 show that when the sample in Example 4 is heated to T... g At +20℃, it can undergo complex large deformations without fracturing under external force. Example 4: The sample was deformed and then reheated to T. gIt can quickly recover to its initial shape at +20℃. Therefore, the sample in Example 4 not only exhibits complex large deformation behavior under thermal activation conditions, but also possesses excellent shape memory behavior.

[0097] Table 2 Mechanical properties and glass transition temperatures of epoxy composite materials in Example 4 and Comparative Example 4

[0098]

[0099] This invention involves dissolving hydroxyl-terminated polyphenylene oxide (PPO) in toluene at 80-100℃, then adding cyanate ester (CE) resin and reacting at 100-120℃ for 2-4 hours. Next, fumed nano-SiO2 is added, and the reaction is continued with stirring for 1-4 hours. This is then added to a 1-3% (w / w) polyvinyl alcohol aqueous solution at 60-90℃ and stirred for 0.5-4 hours, followed by stirring at room temperature for 5-10 hours. The suspension is then washed 5-6 times with deionized water and 2-4 times with acetone to obtain SiO2. 2-CE modified PPO (SiO2-CE@PPO) particles were prepared; then, the SiO2-CE@PPO particles were added to epoxy resin at room temperature, stirred and heated to 100-150℃, and after 10-30 min, a catalyst / accelerator and acid anhydride were added. The reaction was carried out at 100-150℃ with stirring for 0.5-2 h, and after vacuum degassing at 80-100℃, the mixture was injected into a mold and then cured according to a temperature program of 130-200℃ / 4-6 h to obtain the epoxy resin material system. The prepared epoxy resin system has high mechanical properties (flexural strength: ~145MPa; impact strength: ~59kJ / m). 2 It has excellent thermal properties (glass transition temperature: ~136℃), process stability, and excellent complex large deformation and shape memory properties.

Claims

1. A method of making a high-strength, large-deformation shape memory epoxy resin system, characterized by, The method comprises the following steps: (1) heating and reacting hydroxyl-terminated polyphenyl ether with cyanate ester resin, then adding silica, continuing to react, then mixing with polyvinyl alcohol solution, and reacting again to obtain SiO2-CE modified PPO particles; (2) mixing and reacting the SiO2-CE modified PPO particles with epoxy resin, then adding a catalyst and an acid anhydride to pre-polymerize to obtain a prepolymer; or mixing and reacting the SiO2-CE modified PPO particles with epoxy resin, then adding a catalyst, an accelerator and an acid anhydride to pre-polymerize to obtain a prepolymer; (3) curing the prepolymer to obtain a high-strength large-deformation shape memory epoxy resin system; The number average molecular weight of the hydroxyl-terminated polyphenyl ether is 1100-3000; the cyanate ester resin is a bisphenol A type cyanate ester resin; the particle size of the silica is 7-40 nanometers; the epoxy resin comprises one or more of a glycidyl ether type epoxy resin, a glycidyl ester type epoxy resin, a glycidyl amine type epoxy resin, an alicyclic epoxy resin and a linear aliphatic epoxy compound; the acid anhydride is an acid anhydride with a melting point lower than 130 DEG C; the catalyst comprises a metal organic compound; and the accelerator comprises a tertiary amine compound; The mass ratio of the hydroxyl-terminated polyphenyl ether, the cyanate ester resin, the silica and the polyvinyl alcohol solution is (10-20):(1-5):(1-3):(100-300); and the mass ratio of the epoxy resin, the SiO2-CE modified PPO particles, the acid anhydride, the catalyst and the accelerator is 100:(10-45):(25-50):(0.1-3):(0-10).

2. The preparation method of the high-strength, large-deformation shape memory epoxy resin system according to claim 1, characterized in that, The curing is carried out at 130-200 DEG C for 4-6 hours.

3. A process for the preparation of a prepolymer for high-strength, large-deformation shape memory epoxy resin systems, characterized in that The method comprises the following steps: (1) heating and reacting hydroxyl-terminated polyphenyl ether with cyanate ester resin, then adding silica, continuing to react, then mixing with polyvinyl alcohol solution, and reacting again to obtain SiO2-CE modified PPO particles; (2) mixing and reacting the SiO2-CE modified PPO particles with epoxy resin, then adding a catalyst and an acid anhydride to pre-polymerize to obtain a prepolymer; or mixing and reacting the SiO2-CE modified PPO particles with epoxy resin, then adding a catalyst, an accelerator and an acid anhydride to pre-polymerize to obtain a prepolymer; The number average molecular weight of the hydroxyl-terminated polyphenyl ether is 1100-3000; the cyanate ester resin is a bisphenol A type cyanate ester resin; the particle size of the silica is 7-40 nanometers; the epoxy resin comprises one or more of a glycidyl ether type epoxy resin, a glycidyl ester type epoxy resin, a glycidyl amine type epoxy resin, an alicyclic epoxy resin and a linear aliphatic epoxy compound; the acid anhydride is an acid anhydride with a melting point lower than 130 DEG C; the catalyst comprises a metal organic compound; and the accelerator comprises a tertiary amine compound; The mass ratio of hydroxyl-terminated polyphenyl ether, cyanate ester resin, silicon dioxide, polyvinyl alcohol solution is (10-20):(1-5):(1-3):(100-300); the mass ratio of epoxy resin, SiO2-CE modified PPO particles, anhydride, catalyst, accelerator is 100:(10-45):(25-50):(0.1-3):(0-10).

4. The production method according to claim 1 or 3, characterized by, In step (1), the temperature of the heating reaction is 100-120℃, and the time is 2-4h; the temperature of the continuous reaction is 100-120℃, and the time is 1-4h; the temperature of the third reaction is 60-90℃, and the time is 0.5-4h, followed by room temperature reaction for 5-10h; in step (2), the temperature of the mixing reaction is 100-150℃, and the time is 10-30min; the temperature of the prepolymerization reaction is 100-150℃, and the time is 0.5-2h.

5. The high-strength large-deformation shape memory epoxy resin system or the high-strength large-deformation shape memory prepolymer prepared by the preparation method of claim 1 or 3.

6. The use of the high-strength large-deformation shape memory epoxy resin system or the high-strength large-deformation shape memory prepolymer of claim 5 in the preparation of an epoxy resin material.

7. An epoxy resin material, characterized by, The raw materials for preparing the epoxy resin material include the high-strength large-deformation shape memory epoxy resin system or the high-strength large-deformation shape memory prepolymer of claim 5.

8. The epoxy material of claim 7, wherein, The epoxy resin material has large-deformation shape memory performance.

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