A ceramifiable shape memory polymer, a ceramic member and a method for producing the same

Abstract

The application relates to a ceramifiable shape memory polymer, a ceramic member and a preparation method thereof, and belongs to the technical field of shape memory materials. The preparation raw material of the ceramifiable shape memory polymer comprises 4,4'-bismaleimide diphenylmethane, 1,3-di(4-aminophenoxy)benzene, bisaminopropyl-terminated polydimethylsiloxane and a curing agent. The ceramifiable shape memory polymer provided by the application can be edited in shape during the heating process, does not need to be assisted by ceramic particles, can be ceramified at a lower temperature, obtains a ceramic member, can meet the preparation requirements of a complex structure ceramic member, and widens the application scenarios of the shape memory polymer.

Description

Technical Field

[0001] This invention relates to the field of shape memory materials technology, and in particular to a ceramicizable shape memory polymer, ceramic components, and a method for preparing the same. Background Technology

[0002] Shape memory polymers (SMPs) are an emerging type of smart material with a unique shape memory effect, capable of automatically returning to their initial shape under external stimuli. They offer advantages such as high designability, diverse excitation methods, and lightweight yet high strength, making them promising for applications in aerospace, biomedicine, intelligent manufacturing, and mechanical engineering. Ceramic materials, as one of the most promising materials besides metals and polymers, have been widely used in aerospace, biomedicine, and mechanical structures, with high-temperature ceramics being particularly crucial for the aerospace field. However, shape memory polymers lack high-temperature resistance and suffer from low strength at high temperatures, making them unsuitable for use in high-temperature environments or even open-flame conditions. With the development of aerospace, electronic energy, and other fields, higher demands are being placed on the complexity of ceramic components. The inherent brittleness, low impact resistance, and fragility of ceramic materials lead to complex molding processes for irregularly shaped ceramic structures, limiting the expansion of their application areas.

[0003] Therefore, there is an urgent need to provide a ceramicizable shape memory polymer that can be shaped during the heating process and formed into ceramic components under high-temperature sintering, which can help form complex ceramic components and is expected to broaden its application fields. Summary of the Invention

[0004] To address one or more technical problems existing in the prior art, this invention provides a ceramicizable shape memory polymer, ceramic components, and a method for preparing the same. The ceramicizable shape memory polymer provided by this invention can be shaped during the heating process, and ceramic components can be obtained at a relatively low sintering temperature without the need for ceramic particles. This can meet the preparation requirements of complex structure ceramic components and broaden the application scenarios of shape memory polymers.

[0005] The present invention provides a ceramicizable shape memory polymer in a first aspect, wherein the raw materials for preparing the ceramicizable shape memory polymer include: 4,4'-bismaleimide diphenylmethane, 1,3-bis(4-aminophenoxy)benzene, diaminopropyl-terminated polydimethylsiloxane, and a curing agent.

[0006] Preferably, the molar ratio of 4,4'-bismaleimide diphenylmethane to 1,3-bis(4-aminophenoxy)benzene is 1:0.1 to 0.9;

[0007] The molar ratio of 4,4'-bismaleimide diphenylmethane to diaminopropyl-terminated polydimethylsiloxane is 1:0.1 to 0.9, preferably, the diaminopropyl-terminated polydimethylsiloxane has an average molecular weight of 500 to 5000; and / or

[0008] The molar ratio of 4,4'-bismaleimide diphenylmethane to the curing agent is 1:0.1 to 1. Preferably, the curing agent is a curing agent with double-ended epoxy groups. More preferably, the curing agent includes, but is not limited to, one or more of the following: double-ended polydimethylsiloxane, bisphenol A diglycidyl ether, and 1,4-butanediol diglycidyl ether.

[0009] Preferably, the raw materials for preparing the ceramizable shape memory polymer further include at least one of room temperature curing silicone rubber and ceramic materials.

[0010] Preferably, the amount of the room-temperature curing silicone rubber used does not exceed twice the mass of 4,4'-bismaleimide diphenylmethane; more preferably, the room-temperature curing silicone rubber is an addition-type silicone rubber; and / or

[0011] The amount of the ceramic material used does not exceed twice the mass of 4,4'-bismaleimide diphenylmethane. Preferably, the ceramic material includes, but is not limited to, one or more of zirconium boride, zirconium oxide, aluminum oxide, and silicon dioxide.

[0012] In a second aspect, the present invention provides a method for preparing the ceramizable shape memory polymer described in the first aspect, the method comprising:

[0013] S1. Mix 4,4'-bismaleimide diphenylmethane, 1,3-bis(4-aminophenoxy)benzene, diaminopropyl-terminated polydimethylsiloxane and solvent, and then perform a prepolymerization reaction to obtain a prepolymer;

[0014] S2. Mix the prepolymer with the curing agent, remove the solvent, and obtain the premix;

[0015] S3. The premix is ​​thermosetting to obtain a ceramicizable shape memory polymer.

[0016] Preferably, the prepolymerization reaction is carried out by reflux at 40–90°C for 18–36 hours;

[0017] The thermosetting temperature is 50–200°C, and the time is 3–10 hours; preferably, the thermosetting involves first holding at 40–60°C for 1–2 hours, then holding at 100–130°C for 1–4 hours, and finally holding at 200–220°C for 1–4 hours; and / or

[0018] The solvent is at least one of tetrahydrofuran, dichloromethane, and acetone.

[0019] Preferably, the premix further includes at least one of room temperature curing silicone rubber and ceramic materials.

[0020] In a third aspect, the present invention provides a ceramic component obtained by high-temperature sintering of the ceramicizable shape memory polymer described in the first aspect.

[0021] Preferably, the high-temperature sintering temperature is 800–1600°C, and the sintering atmosphere is nitrogen, argon, or air.

[0022] Preferably, the ceramicizable shape memory polymer is temporarily shaped prior to the high-temperature sintering.

[0023] Compared with the prior art, the present invention has at least the following beneficial effects:

[0024] This invention discloses a ceramicizable shape memory polymer prepared from 4,4'-bismaleimide diphenylmethane, 1,3-bis(4-aminophenoxy)benzene, diaminopropyl-terminated polydimethylsiloxane, and a curing agent. The polymer can be ceramized during the heating process without the need for ceramic particles, achieving ceramic components at relatively low sintering temperatures. This meets the requirements for preparing complex ceramic components, broadening the application scenarios of shape memory polymers and potentially finding applications in fields such as intelligent solar panel deployment, intelligent hinges, intelligent pods, and ceramic catalyst supports.

[0025] The ceramicizable shape memory polymer provided by this invention can be made into a ceramic component precursor with an initial shape. Utilizing its shape memory function, the ceramic component precursor can be given a temporary shape before transportation and storage, thereby achieving the purpose of saving storage space and protecting fragile parts of the component during transportation and storage. During the sintering process, the ceramic component precursor with a temporary shape will automatically return to the ceramic component precursor with an initial shape, and finally form a ceramic component with the initial shape. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 The DMA curve of the ceramicizable shape memory polymer obtained in Example 1;

[0028] Figure 2This is a picture of the ceramicizable shape memory polymer prepared in Example 1 after being shaped at 170°C, cooled and solidified, and placed at room temperature for 48 hours to fix its shape.

[0029] Figure 3 The XRD curves of the ceramic components obtained after sintering the ceramicizable shape memory polymer prepared in Example 1 are shown.

[0030] Figure 4 This is the three-point bending curve of the ceramic component obtained after sintering the ceramicizable shape memory polymer prepared in Example 2;

[0031] Figure 5 The three-point bending curve of the ceramic component obtained after sintering the ceramicizable shape memory polymer prepared in Example 3 is shown.

[0032] Figure 6 The DMA curves of the shape memory polymer prepared in Comparative Example 1 are shown.

[0033] Figure 7 The image shows the shape memory polymer prepared in Comparative Example 1 after being shaped at 170°C, cooled and solidified, and then left at room temperature for a long time to fix its shape.

[0034] Figure 8 Comparative Example 3 shows the phase separation phenomenon that occurred during the preparation of shape memory polymer. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0036] The present invention provides a ceramicizable shape memory polymer in a first aspect, wherein the raw materials for preparing the ceramicizable shape memory polymer include: 4,4'-bismaleimide diphenylmethane, 1,3-bis(4-aminophenoxy)benzene, diaminopropyl-terminated polydimethylsiloxane, and a curing agent.

[0037] This invention presents a ceramicizable shape memory polymer prepared from 4,4'-bismaleimide diphenylmethane, 1,3-bis(4-aminophenoxy)benzene, diaminopropyl-terminated polydimethylsiloxane, and a curing agent. This polymer allows for shape editing during the heating process without the need for ceramic particles, achieving ceramicization at relatively low sintering temperatures (as low as 800°C) to obtain ceramic components. This meets the requirements for preparing complex ceramic components, broadening the application scenarios of shape memory polymers and potentially finding applications in fields such as intelligent solar panel deployment, intelligent hinges, and intelligent pod stalks.

[0038] According to some preferred embodiments, the molar ratio of 4,4'-bismaleimide diphenylmethane to 1,3-bis(4-aminophenoxy)benzene is 1:0.1 to 0.9 (for example, it can be 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8 or 1:0.9).

[0039] The molar ratio of 4,4'-bismaleimide diphenylmethane to diaminopropyl-terminated polydimethylsiloxane is 1:0.1 to 0.9 (e.g., 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, or 1:0.9), preferably, the diaminopropyl-terminated polydimethylsiloxane has an average molecular weight of 500 to 5000; and / or

[0040] The molar ratio of 4,4'-bismaleimide diphenylmethane to the curing agent is 1:0.1 to 1 (for example, it can be 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9 or 1:1). Preferably, the curing agent is a curing agent with double-ended epoxy groups. More preferably, the curing agent includes, but is not limited to, one or more of the following: double-ended polydimethylsiloxane, bisphenol A diglycidyl ether, and 1,4-butanediol diglycidyl ether.

[0041] According to some preferred embodiments, the raw materials for preparing the ceramizable shape memory polymer also include at least one of room temperature curing silicone rubber and ceramic materials.

[0042] This invention introduces room-temperature curing silicone rubber into the raw materials to form a shape memory polymer with an interpenetrating network. The shape memory network (formed by the prepolymer) interpenetrates with the silicone rubber network. During ceramization, the shape memory network undergoes pyrolysis, releasing small molecule gases and creating pores. The silicone rubber network, on the other hand, releases relatively less gas through pyrolysis, resulting in volume shrinkage and a more compact structure. This synergistic effect balances the shape memory properties of the shape memory polymer before ceramization with the mechanical load-bearing properties after ceramization, thus improving the mechanical load-bearing capacity of the sintered ceramic component. Introducing ceramic materials allows for higher-temperature sintering, resulting in reinforced ceramic components and further enhancing the mechanical load-bearing capacity of the sintered ceramic component.

[0043] According to some preferred embodiments, the amount of room-temperature curing silicone rubber used does not exceed twice the mass of 4,4'-bismaleimide diphenylmethane. Preferably, the room-temperature curing silicone rubber is an addition-type silicone rubber. This invention controls the amount of room-temperature curing silicone rubber within the above range to ensure the acquisition of a ceramizable shape memory polymer with an interpenetrating network structure. The inventors have found that if the amount of room-temperature curing silicone rubber is too large, phase separation will occur during the preparation of the ceramizable shape memory polymer, making it impossible to obtain the ceramizable shape memory polymer.

[0044] According to some preferred embodiments, the amount of ceramic material used does not exceed twice the mass of 4,4'-bismaleimide diphenylmethane. Preferably, the ceramic material includes, but is not limited to, one or more of zirconium boride, zirconium oxide, aluminum oxide, and silicon dioxide. This invention controls the amount of ceramic material within the above range to ensure the acquisition of a ceramicizable shape memory polymer with excellent shape memory properties. The inventors have found that if the amount of ceramic material is too large, it will lead to a decrease in the shape memory properties of the ceramicizable shape memory polymer, affecting its shaping and cutting performance.

[0045] In a second aspect, the present invention provides a method for preparing the ceramizable shape memory polymer described in the first aspect, the method comprising:

[0046] S1. Mix 4,4'-bismaleimide diphenylmethane, 1,3-bis(4-aminophenoxy)benzene, diaminopropyl-terminated polydimethylsiloxane and solvent, and then perform a prepolymerization reaction to obtain a prepolymer;

[0047] S2. Mix the prepolymer with the curing agent, remove the solvent, and obtain the premix;

[0048] S3. The premix is ​​thermosetting to obtain a ceramicizable shape memory polymer.

[0049] This invention involves prepolymerizing 4,4'-bismaleimide diphenylmethane, 1,3-bis(4-aminophenoxy)benzene, and diaminopropyl-terminated polydimethylsiloxane to form a prepolymer, which is then cured under the action of a curing agent to obtain a ceramicizable shape memory polymer.

[0050] According to some preferred embodiments, the prepolymerization reaction is carried out by reflux at 40–90°C (e.g., 40°C, 50°C, 60°C, 70°C, 80°C, or 90°C) for 18–36 hours.

[0051] The thermosetting temperature is 50–200°C (e.g., 50°C, 80°C, 100°C, 120°C, 150°C, 160°C, 180°C, or 200°C), and the time is 3–10 hours; preferably, the thermosetting involves first holding at 40–60°C for 1–2 hours, then holding at 100–130°C for 1–4 hours, and finally holding at 200–220°C for 1–4 hours; and / or

[0052] The solvent is at least one of tetrahydrofuran, dichloromethane, and acetone.

[0053] According to some preferred embodiments, the premix also includes at least one of room temperature curing silicone rubber and ceramic materials.

[0054] This invention incorporates at least one of room-temperature curing silicone rubber and ceramic material during the mixing process of prepolymer and curing agent, thereby further improving the performance of the sintered ceramic component. By introducing room-temperature curing silicone rubber, a shape memory polymer can form an interpenetrating network structure with the prepolymer under the action of the curing agent. Introducing ceramic material can improve the mechanical load-bearing capacity of the sintered ceramic component, resulting in a reinforced ceramic component.

[0055] In a third aspect, the present invention provides a ceramic component obtained by high-temperature sintering of the ceramicizable shape memory polymer described in the first aspect.

[0056] According to some preferred embodiments, the high-temperature sintering temperature is 800–1600°C (for example, it can be 800°C, 900°C, 1000°C, 1100°C, 1200°C, 1300°C, 1400°C, 1500°C or 1600°C), and the sintering atmosphere is nitrogen, argon or air.

[0057] The ceramicizable shape memory polymer of the present invention can be ceramicized to obtain ceramic components at a relatively low sintering temperature (as low as 800°C), which is significantly lower than the sintering temperature (1300-1700°C) of ceramics sintered using ordinary ceramic fillers.

[0058] According to some preferred embodiments, the ceramicizable shape memory polymer is temporarily shaped prior to the high-temperature sintering.

[0059] When molding complex ceramic components, shape memory polymers are first used to create the desired shape (a precursor ceramic component with an initial shape). To prevent easily damaged parts (such as perforated or filamentous structures) from being damaged during storage and transportation, the temperature is typically raised above the glass transition temperature, and an external force is applied to give the precursor a temporary shape (e.g., a flat plate). Then, the external force is maintained while the temperature is lowered to room temperature to fix the shape, and the external force is removed, resulting in a precursor ceramic component with a temporary shape. During sintering, when the temperature reaches above the glass transition temperature, the precursor ceramic component with the temporary shape automatically reverts to its initial shape. As the temperature continues to rise, sintering completes the process, forming the ceramic component with the initial shape.

[0060] To more clearly illustrate the technical solution and advantages of the present invention, the present invention will be further described below with reference to embodiments. The present invention does not specifically limit the source of the reagents used in the embodiments and comparative examples; they can be directly purchased or synthesized in-house. The parts in the following embodiments and comparative examples of the present invention are parts by mass.

[0061] Example 1

[0062] A method for preparing a ceramizable shape memory polymer, comprising:

[0063] S1. Mix 10 parts of 4,4'-bismaleimide diphenylmethane, 5 parts of diaminopropyl-terminated polydimethylsiloxane (average molecular weight 2000), 5 parts of 1,3-bis(4-aminophenoxy)benzene and 120 parts of dichloromethane, stir until the solution is clear, place it in an oil bath, and reflux at 50°C for 24 hours to obtain the prepolymer.

[0064] S2. Add 5 parts of bisphenol A diglycidyl ether to the above prepolymer, stir and mix well, pour into a mold, let stand at room temperature for 24 hours, remove the solvent, and obtain the premix.

[0065] S3. Place the above premix in an oven and cure it according to the following curing procedure: first keep it at 40℃ for 4 hours, then keep it at 120℃ for 2 hours, and finally keep it at 200℃ for 1 hour. After demolding, a ceramicizable shape memory polymer is obtained.

[0066] A method for preparing a ceramic component, comprising:

[0067] The ceramicizable shape memory polymer is placed on a heating stage and heated to 180°C to give it a temporary shape. Then it is placed in a tube furnace and sintered at 800°C for 1 hour in a nitrogen atmosphere to obtain a ceramic component.

[0068] Depend on Figure 1 It can be seen that the glass transition temperature (Tg) of the ceramizable shape memory polymer prepared in this embodiment is 153.42℃. It should be noted that the horizontal axis in the figure represents temperature, the left vertical axis represents the storage modulus, and the right vertical axis represents the loss factor.

[0069] Depend on Figure 2 It can be seen that the ceramicizable shape memory polymer (initially in sheet form) prepared in this embodiment can basically maintain its shape after being shaped at 170°C and cooled to solidify, and then placed at room temperature for 48 hours.

[0070] Depend on Figure 3 As can be seen, the XRD curve of the ceramic component obtained after sintering the ceramicizable shape memory polymer prepared in this embodiment shows two peaks of free carbon and no other crystalline state, proving that it is an amorphous SiOC ceramic.

[0071] Example 2

[0072] A method for preparing a ceramizable shape memory polymer, comprising:

[0073] S1. Mix 10 parts of 4,4'-bismaleimide diphenylmethane, 8 parts of diaminopropyl-terminated polydimethylsiloxane (average molecular weight 2000), 2 parts of 1,3-bis(4-aminophenoxy)benzene and 120 parts of dichloromethane, stir until the solution is clear, place it in an oil bath, and reflux at 50°C for 24 hours to obtain the prepolymer.

[0074] S2. Add 5 parts of resorcinol diglycidyl ether to the above prepolymer, stir and mix well, pour into a mold, let stand at room temperature for 24 hours, remove the solvent, and obtain the premix.

[0075] S3. Place the above premix in an oven and cure it according to the following curing procedure: first keep it at 40℃ for 4 hours, then keep it at 120℃ for 2 hours, and finally keep it at 200℃ for 1 hour. After demolding, a ceramicizable shape memory polymer is obtained.

[0076] A method for preparing a ceramic component, comprising:

[0077] The ceramicizable shape memory polymer is placed on a heating stage and heated to 180°C to give it a temporary shape. Then it is placed in a tube furnace and sintered at 800°C for 1 hour in a nitrogen atmosphere to obtain a ceramic component.

[0078] Example 3

[0079] S1. Mix 10 parts of 4,4'-bismaleimide diphenylmethane, 8 parts of diaminopropyl-terminated polydimethylsiloxane (average molecular weight 2000), 2 parts of 1,3-bis(4-aminophenoxy)benzene and 120 parts of dichloromethane, stir until the solution is clear, place it in an oil bath, and reflux at 50°C for 24 hours to obtain the prepolymer.

[0080] S2. Add 5 parts of resorcinol diglycidyl ether and 15 parts of zirconium boride ceramic powder to the above prepolymer, stir and mix well, pour into a mold, let stand at room temperature for 24 hours, remove the solvent, and obtain the premix.

[0081] S3. Place the above premix in an oven and cure it according to the following curing procedure: first keep it at 40℃ for 4 hours, then keep it at 120℃ for 2 hours, and finally keep it at 200℃ for 1 hour. After demolding, a ceramicizable shape memory polymer is obtained.

[0082] A method for preparing a ceramic component, comprising:

[0083] The ceramicizable shape memory polymer is placed on a heating stage and heated to 180°C to give it a temporary shape. Then it is placed in a tube furnace and sintered at 800°C for 1 hour and 1300°C for 1 hour in a nitrogen atmosphere to obtain a ceramic component.

[0084] Depend on Figure 4-5 It can be seen that, compared with the ceramic components obtained by sintering the ceramizable shape memory polymer prepared in Example 2, ( Figure 4 Compared to the ceramic components obtained by sintering the ceramizable shape memory polymer prepared in Example 3, the ceramic components obtained by sintering the ceramizable shape memory polymer are superior. Figure 5 The ceramic powder exhibits higher flexural strength and flexural modulus. Therefore, the introduction of ceramic powder can improve the flexural strength and flexural modulus of ceramic components.

[0085] Furthermore, compared with the ceramic component obtained by sintering the ceramizable shape memory polymer prepared in Example 2, the ceramic component obtained by sintering the ceramizable shape memory polymer prepared in Example 3 has better mechanical properties.

[0086] Example 4

[0087] S1. Mix 10 parts of 4,4'-bismaleimide diphenylmethane, 5 parts of diaminopropyl-terminated polydimethylsiloxane (average molecular weight 2000), 5 parts of 1,3-bis(4-aminophenoxy)benzene and 120 parts of dichloromethane, stir until the solution is clear, place it in an oil bath, and reflux at 50°C for 24 hours to obtain the prepolymer.

[0088] S2. Add 5 parts of bisphenol A diglycidyl ether and 15 parts of zirconium boride ceramic powder to the above prepolymer, stir and mix well, pour into a mold, let stand at room temperature for 24 hours, remove the solvent, and obtain the premix.

[0089] S3. Place the above premix in an oven and cure it according to the following curing procedure: first keep it at 40℃ for 4 hours, then keep it at 120℃ for 2 hours, and finally keep it at 200℃ for 1 hour. After demolding, a ceramicizable shape memory polymer is obtained.

[0090] A method for preparing a ceramic component, comprising:

[0091] The ceramicizable shape memory polymer is placed on a heating platform and heated to 180°C to give it a temporary shape. Then it is placed in a tube furnace and sintered at 800°C for 1 hour in a nitrogen atmosphere, followed by sintering at 1300°C for 1 hour to obtain a ceramic component.

[0092] Compared with Example 1, the ceramic component obtained by sintering the shape memory polymer prepared by adding ceramic powder in this example has better mechanical properties.

[0093] Example 5

[0094] S1. Mix 10 parts of 4,4'-bismaleimide diphenylmethane, 5 parts of diaminopropyl-terminated polydimethylsiloxane (average molecular weight 2000), 5 parts of 1,3-bis(4-aminophenoxy)benzene and 120 parts of dichloromethane, stir until the solution is clear, place it in an oil bath, and reflux at 50°C for 24 hours to obtain the prepolymer.

[0095] S2. Add 5 parts of bisphenol A diglycidyl ether and 15 parts of room temperature curing silicone rubber to the above prepolymer, stir and mix well, pour into a mold, place at room temperature for 24 hours, remove the solvent, and obtain the premix.

[0096] S3. Place the above premix in an oven and cure it according to the following curing procedure: first keep it at 40℃ for 4 hours, then keep it at 120℃ for 2 hours, and finally keep it at 200℃ for 1 hour. After demolding, a ceramicizable shape memory polymer is obtained.

[0097] A method for preparing a ceramic component, comprising:

[0098] The ceramicizable shape memory polymer is placed on a heating stage and heated to 180°C to give it a temporary shape. Then it is placed in a tube furnace and sintered at 800°C for 1 hour in a nitrogen atmosphere to obtain a ceramic component.

[0099] This embodiment introduces room-temperature curable silicone rubber to form an interpenetrating network structure, resulting in a ceramizable shape memory polymer with an interpenetrating network structure. Compared to Example 1, the obtained ceramizable shape memory polymer has a higher silicon-oxygen segment content, and the ceramic parts obtained after sintering have better mechanical load-bearing properties.

[0100] Example 6

[0101] S1. Add 10 parts of 4,4'-bismaleimide diphenylmethane, 5 parts of diaminopropyl-terminated polydimethylsiloxane (average molecular weight 2000), 5 parts of 1,3-bis(4-aminophenoxy)benzene, and 120 parts of dichloromethane solvent. Stir until the solution is clear, place it in an oil bath, and reflux at 50°C for 24 hours to obtain the prepolymer.

[0102] S2. Add 5 parts of bisphenol A diglycidyl ether, 15 parts of room temperature curing silicone rubber, and 15 parts of zirconium boride ceramic powder to the above prepolymer, stir and mix well, pour into a mold, place at room temperature for 24 hours, remove the solvent, and obtain the premix.

[0103] S3. Place the above premix in an oven and cure it according to the following curing procedure: first keep it at 40℃ for 4 hours, then keep it at 120℃ for 2 hours, and finally keep it at 200℃ for 1 hour. After demolding, a ceramicizable shape memory polymer is obtained.

[0104] A method for preparing a ceramic component, comprising:

[0105] The ceramicizable shape memory polymer is placed on a heating platform and heated to 180°C to give it a temporary shape. Then it is placed in a tube furnace and sintered at 800°C for 1 hour in a nitrogen atmosphere, followed by sintering at 1300°C for 1 hour to obtain a ceramic component.

[0106] This embodiment introduces room-temperature curing silicone rubber to form an interpenetrating network structure, adds ceramic powder for reinforcement, and obtains a reinforced ceramic component after sintering. Compared with Example 5, the ceramic component prepared in this embodiment has better mechanical load-bearing properties.

[0107] Comparative Example 1:

[0108] The method is basically the same as in Example 1, except that in step S1, 1,3-bis(4-aminophenoxy)benzene is not added, and the amount of diaminopropyl-terminated polydimethylsiloxane is 10 parts.

[0109] like Figure 6 As shown, an excessive content of flexible silicon-oxygen segments in the raw materials results in a larger peak width in the loss factor, leading to a decrease in shape memory performance at room temperature. It should be noted that the horizontal axis in the figure represents temperature, the left vertical axis represents storage modulus, and the right vertical axis represents the loss factor.

[0110] like Figure 7 As shown, the shape memory polymer (initially sheet-like) prepared in this comparative example gradually recovered to its initial shape after being shaped at 170°C, cooled and solidified, and then placed at room temperature for 48 hours.

[0111] Comparative Example 2

[0112] The method is basically the same as in Example 1, except that in step S1, diaminopropyl-terminated polydimethylsiloxane was not added, and the amount of 1,3-bis(4-aminophenoxy)benzene was 10 parts.

[0113] The shape memory polymer obtained in this comparative example, after sintering, produces components that do not contain silicon and whose main component is free carbon; therefore, they cannot be called ceramic components.

[0114] Comparative Example 3

[0115] It is basically the same as Example 5, except that in step S2, the amount of room temperature curing silicone rubber used is 55 parts.

[0116] In this comparative example, due to the excessive amount of silicone rubber added in the raw materials, phase separation occurred during the mixing process, exhibiting a macroscopic island structure (such as...). Figure 8 As shown in the figure, it is impossible to obtain ceramicizable shape memory polymers.

[0117] Comparative Example 4

[0118] It is basically the same as Example 4, except that in step S2, the amount of ceramic powder zirconium boride is 40 parts.

[0119] In this comparative example, the excessive amount of ceramic powder added to the raw materials affected the continuity of the matrix resin, resulting in poor shape memory properties of the composite material and impacting its shaping and cutting performance.

[0120] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A ceramicizable shape memory polymer, characterized in that, The raw materials for preparing the ceramicizable shape memory polymer include: 4,4'-bismaleimide diphenylmethane, 1,3-bis(4-aminophenoxy)benzene, diaminopropyl-terminated polydimethylsiloxane, and a curing agent; The molar ratio of 4,4'-bismaleimide diphenylmethane to 1,3-bis(4-aminophenoxy)benzene is 1:0.1~0.9; the molar ratio of 4,4'-bismaleimide diphenylmethane to diaminopropyl-terminated polydimethylsiloxane is 1:0.1~0.9; and the molar ratio of 4,4'-bismaleimide diphenylmethane to the curing agent is 1:0.1~1. The raw materials for preparing the ceramizable shape memory polymer also include at least one of room temperature curing silicone rubber and ceramic materials; the amount of room temperature curing silicone rubber used does not exceed twice the mass of 4,4'-bismaleimide diphenylmethane; the amount of ceramic materials used does not exceed twice the mass of 4,4'-bismaleimide diphenylmethane.

2. The ceramizable shape memory polymer according to claim 1, characterized in that, The average molecular weight of diaminopropyl-terminated polydimethylsiloxane is 500-5000; and / or The curing agent is a curing agent with double-ended epoxy groups.

3. The ceramizable shape memory polymer according to claim 1, characterized in that, The curing agent includes one or more of the following: epoxy group-terminated polydimethylsiloxane, bisphenol A diglycidyl ether, and 1,4-butanediol diglycidyl ether.

4. The ceramizable shape memory polymer according to claim 1, characterized in that, The room-temperature curing silicone rubber is an addition-type silicone rubber; and / or The ceramic material includes one or more of zirconium boride, zirconium oxide, aluminum oxide, and silicon dioxide.

5. A method for preparing the ceramizable shape memory polymer according to any one of claims 1-4, characterized in that, The preparation method includes: S1. Mix 4,4'-bismaleimide diphenylmethane, 1,3-bis(4-aminophenoxy)benzene, diaminopropyl-terminated polydimethylsiloxane and solvent, and then perform a prepolymerization reaction to obtain a prepolymer; S2. The prepolymer is mixed with a curing agent, and the solvent is removed to obtain a premix; the premix further includes at least one of room temperature curing silicone rubber and ceramic material; S3. The premix is ​​thermosetting to obtain a ceramicizable shape memory polymer.

6. The preparation method according to claim 5, characterized in that, The prepolymerization reaction is carried out by reflux at 40~90℃ for 18~36 hours; The thermosetting temperature is 50~200℃, and the time is 3~10h; and / or The solvent is at least one of tetrahydrofuran, dichloromethane, and acetone.

7. The preparation method according to claim 6, characterized in that, The thermosetting process involves first holding the product at 40-60℃ for 1-2 hours, then at 100-130℃ for 1-4 hours, and finally at 200-220℃ for 1-4 hours.

8. A ceramic component, characterized in that, It is obtained by high-temperature sintering of the ceramicizable shape memory polymer according to any one of claims 1-4.

9. The ceramic component according to claim 8, characterized in that, The high-temperature sintering temperature is 800~1600℃, and the sintering atmosphere is nitrogen, argon or air.

10. The ceramic component according to claim 8, characterized in that, Prior to the high-temperature sintering, the ceramicizable shape memory polymer is temporarily shaped.

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