Room temperature self-healing polydimethylsiloxane elastomer material and method of making same

Abstract

This invention belongs to the field of materials technology and discloses a room-temperature self-healing polydimethylsiloxane elastomer material and its preparation method. The material is composed of segments R1 containing a polydimethylsiloxane structure, a polymaleic anhydride copolymer structure R2, and a structure R3 containing an aromatic diamino disulfide. In the material, the weight fraction of R1 is 40-75%, the weight fraction of R2 is 20-55%, and the weight fraction of R3 is 3-15%. The material of this invention contains both a polydimethylsiloxane structure and an aromatic disulfide structure, has a tensile strength of 0.5-5 MPa, an elongation at break of 100-800%, and can repair itself at room temperature after fracture, with a repair rate exceeding 70% after 24 hours.

Description

Technical Field

[0001] This invention belongs to the field of materials technology, specifically relating to a room-temperature self-healing polydimethylsiloxane elastomer material and its preparation method. Background Technology

[0002] Polydimethylsiloxane (PDMS) possesses good thermal stability, biocompatibility, and UV resistance, but its mechanical strength is poor, making it unsuitable for use alone. It is often used to form elastomers through chain extension and cross-linking processes. Introducing reversible covalent bonds or dynamic non-covalent interactions into PDMS elastomers to form reversible cross-linked structures yields responsive, self-healing elastomers. These self-healing elastomers can repair themselves under certain conditions when cracks, scratches, or fractures occur, achieving reuse. They can also be recycled and reprocessed after use, forming a cycle that reduces waste and promotes environmental protection and carbon reduction.

[0003] The key to self-healing materials lies in the conditions for self-healing. Generally, self-healing requires sufficient mobility and energy in the molecular chain structure of the material to achieve a rapid equilibrium of "fracture-crosslinking." High-temperature repair may be difficult to achieve, therefore, room-temperature repair has significant application value. Disulfide compounds containing aromatic structures can impart repair properties to materials at room temperature. Therefore, adding amino-containing aromatic disulfides to polydimethylsiloxane elastomers can form polydimethylsiloxane elastomers with room-temperature self-healing properties.

[0004] Common crosslinking agents such as binary or polyisocyanates have certain toxicity, and the synthesis process often requires the use of raw materials such as phosgene, which will bring additional environmental pressure to PDMS elastomers. Summary of the Invention

[0005] To address the aforementioned problems in the existing technology, the purpose of this invention is to provide a room-temperature self-healing polydimethylsiloxane (PDMS) elastomer material and its preparation method. This material can achieve self-healing at room temperature, while also possessing good elasticity and processability. Moreover, this material is prepared using a non-toxic, harmless, and readily available crosslinking agent.

[0006] The first aspect of the present invention provides a room temperature self-healing polydimethylsiloxane elastomer material, which is composed of a segment R1 containing a polydimethylsiloxane structure, a polymaleic anhydride copolymer structure R2, and a structure R3 having an aromatic diamino disulfide.

[0007] In the material, the weight fraction of R1 is 40-75%, the weight fraction of R2 is 20-55%, and the weight fraction of R3 is 3-15%.

[0008] A second aspect of the present invention provides a method for preparing the above-mentioned room-temperature self-healing polydimethylsiloxane elastomer material, the method comprising:

[0009] 1) Maleic anhydride is polymerized with one or more monomers containing double bonds using living free radical polymerization to obtain polymaleic anhydride copolymer, which is then prepared into a solution;

[0010] 2) Prepare solutions of polydimethylsiloxane containing diamine groups and aromatic diamine compounds containing disulfides, respectively;

[0011] 3) Mix the three solutions obtained in steps 1) and 2), react at room temperature, remove the solvent, and obtain room temperature self-healing polydimethylsiloxane elastomer material.

[0012] The material of this invention has a polydimethylsiloxane structure and an aromatic disulfide structure, with a tensile strength of 0.5-5 MPa and an elongation at break of 100-800%. It can be repaired at room temperature after fracture, and the repair rate can reach more than 70% after 24 hours (repair rate = tensile strength after repair / tensile strength before repair × 100%), with a maximum of 97.5%.

[0013] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of a room-temperature self-healing polydimethylsiloxane elastomer material according to an embodiment.

[0015] Figure 2 This is a schematic diagram of another room-temperature self-healing polydimethylsiloxane elastomer material as an example. Detailed Implementation

[0016] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0017] According to a first aspect of the present invention, the present invention provides a room temperature self-healing polydimethylsiloxane elastomer material, the material being composed of a segment R1 containing a polydimethylsiloxane structure, a polymaleic anhydride copolymer structure R2, and a structure R3 having an aromatic diamino disulfide.

[0018] In the material, the weight fraction of R1 is 40-75%, the weight fraction of R2 is 20-55%, and the weight fraction of R3 is 3-15%.

[0019] In this invention, R1 is formed from a linear polydimethylsiloxane containing diamino groups; R2 is formed from a linear copolymer containing maleic anhydride, such as polymethyl methacrylate-maleic anhydride copolymer or polystyrene-maleic anhydride copolymer; and R3 is formed from an aromatic diamine compound containing disulfide, such as 4,4'-diaminodiphenyl disulfide or 2,2'-diaminodiphenyl disulfide.

[0020] Preferably, in the material, the weight fraction of R1 is 45-70%, the weight fraction of R2 is 20-50%, and the weight fraction of R3 is 3-10%.

[0021] According to a second aspect of the present invention, the present invention provides a method for preparing the above-mentioned room temperature self-healing polydimethylsiloxane elastomer material, the method comprising:

[0022] 1) Maleic anhydride is polymerized with one or more monomers containing double bonds using living free radical polymerization to obtain polymaleic anhydride copolymer, which is then prepared into a solution;

[0023] 2) Prepare solutions of polydimethylsiloxane containing diamine groups and aromatic diamine compounds containing disulfides, respectively;

[0024] 3) Mix the three solutions obtained in steps 1) and 2), react at room temperature, remove the solvent, and obtain room temperature self-healing polydimethylsiloxane elastomer material.

[0025] In this invention, the monomer containing double bonds can be selected from meth / acrylate monomers and / or styrene monomers; the ratio of maleic anhydride to monomer containing double bonds can be 1:0.8-10, preferably 1:1-6.

[0026] According to the present invention, the living radical polymerization adopts a solution polymerization reaction, the polymerization temperature is 40-120°C, preferably 50-120°C, and the polymerization time is 1-24 h, preferably 2-16 h. The polymerization is carried out under an inert atmosphere.

[0027] The following explanation uses reversible addition-fragmentation chain transfer polymerization (RAFT polymerization) as an example. Monomers, initiators, chain transfer agents, solvents, and other compounds are placed in a reaction vessel. After three purging cycles under vacuum and inert atmosphere, the reaction system is raised to the polymerization temperature to carry out the reaction. After the reaction is complete, the reaction solution is precipitated in methanol and dried.

[0028] In this invention, the number average molecular weight of the polymaleic anhydride copolymer is 1,000-20,000, preferably 1,500-15,000.

[0029] According to the present invention, the number-average molecular weight of the diamine-containing polydimethylsiloxane is 1000-10000. The diamine-containing polydimethylsiloxane is commercially available.

[0030] In this invention, the disulfide-containing aromatic diamine compound can be 4,4'-diaminodiphenyl disulfide and 2,2'-diaminodiphenyl disulfide.

[0031] According to the present invention, the concentration of the solution obtained in steps 1) and 2) can be 10-30 wt%. The solvent for preparing the solution is a good solvent, which can be selected from at least one of dichloromethane, trichloromethane, tetrahydrofuran, and dioxane.

[0032] In step 3) of the present invention, the amount of each material used, calculated per mole of maleic anhydride group in the polymaleic anhydride copolymer, is as follows: the amount of terminal amino group in the polydimethylsiloxane containing diamine groups is 0.20-0.60 mol, preferably 0.25-0.55 mol; the amount of diamine in the aromatic diamine compound containing disulfide is 0.40-0.90 mol, preferably 0.45-0.80 mol.

[0033] According to the present invention, the ring-opening reaction in step 3) is a room temperature reaction, and the reaction time is 0.1-12h, preferably 0.2-8h.

[0034] The substances and parameters not limited in this invention can be selected according to existing technology, which is a conventional technical means in this field.

[0035] The present invention will be further described below with reference to embodiments. However, the invention is not limited to these embodiments.

[0036] In the following embodiments and comparative examples, the data were obtained using the following methods:

[0037] 1. The toughness of polydimethylsiloxane elastomer was tested according to the method of GB / T 1040.2-2006.

[0038] 2. The structure of the material was characterized by proton nuclear magnetic resonance spectroscopy. The segment length was obtained by integrating the nuclear magnetic resonance spectrum. The instrument used was a Bruker 300MHz nuclear magnetic resonance spectrometer, and the solvent was CDCl3.

[0039] 3. Repair method: Prepare the material into a dumbbell-shaped specimen, cut the specimen and quickly place it back in its original shape between two smooth glass plates. Measure the mechanical properties after 24 hours.

[0040] Example 1

[0041] 7.84 g (0.08 mol) of maleic anhydride and 32.0 g (0.32 mol) of methyl methacrylate were placed in a three-necked flask. 7.28 g (0.02 mol) of 2-(dodecyltrithiocarbonyl)-2-methylpropionic acid, 2.42 g of azobisisobutyronitrile, and 80 mL of anhydrous dioxane were added. The system was stirred until homogeneous, then purged with N2 for 20 min. The flask was sealed and placed in an oil bath set to 80 °C for the reaction. After 6 h of reaction, the reaction solution was poured into methanol, filtered, and dried to obtain product PMA1, with a number average molecular weight (Mn) of 2000 and a molecular weight distribution of 1.35. A 20 wt% dichloromethane solution of PMA1 was prepared.

[0042] 20 g of amino-terminated polydimethylsiloxane (PDMS) with Mn of 5000 was dissolved in 75 mL of dichloromethane (containing 0.008 mol of amino groups). The solution was stirred until homogeneous. Then, 50 mL of a 20 wt% dichloromethane solution of PMA1 (containing 0.020 mol of maleic anhydride groups) and 7.5 mL of a 20 wt% dichloromethane solution of 4,4'-diaminodiphenyl disulfide (containing 0.012 mol of amino groups) were quickly added. The mixture was stirred until homogeneous and then reacted at room temperature. The reaction was completed after approximately 1 hour. After removing the solvent, a room-temperature self-healing elastomer material, PDMS-E1, was obtained. The structure of the material is shown below. Figure 1 As shown, n in R1 is 66, x in R2 is 0.2 and y is 0.8. In the material, the weight fraction of R1 is 63.5%, the weight fraction of R2 is 31.7%, and the weight fraction of R3 is 4.8%.

[0043] Example 2

[0044] 7.84 g (0.08 mol) of maleic anhydride and 32 g (0.32 mol) of styrene were placed in a three-necked flask. 7.30 g (0.02 mol) of 2-(dodecyltrithiocarbonyl)-2-methylpropionic acid, 2.41 g of azobisisobutyronitrile, and 100 mL of anhydrous dioxane were added. The system was stirred until homogeneous, then purged with N2 for 20 min. The flask was sealed and placed in an oil bath set to 80 °C for the reaction. After 6 h of reaction, the reaction solution was poured into methanol, filtered, and dried to obtain product PMA4, with a number-average molecular weight (Mn) of 1800 and a molecular weight distribution of 1.29. A 20 wt% dichloromethane solution of PMA4 was prepared.

[0045] 20g of amino-terminated polydimethylsiloxane (PDMS) with Mn of 5000 was dissolved in 75mL of dichloromethane (containing 0.008mol of amino groups). The solution was stirred until homogeneous. Then, 50mL of a 20wt% dichloromethane solution of PMA4 (containing 0.020mol of maleic anhydride groups) and 7.5mL of a 20wt% dichloromethane solution of 4,4'-diaminodiphenyl disulfide (containing 0.012mol of amino groups) were quickly added. The mixture was stirred until homogeneous and then reacted at room temperature. The reaction was completed after approximately 1 hour. After removing the solvent, a room-temperature self-healing elastomer material, PDMS-E2, was obtained. The structure of the material is shown below. Figure 2 As shown, n in R1 is 66, x in R2 is 0.2 and y is 0.8. In the material, the weight fraction of R1 is 63.5%, the weight fraction of R2 is 31.7%, and the weight fraction of R3 is 4.8%.

[0046] Example 3

[0047] 12.74 g (0.13 mol) of maleic anhydride and 27.0 g (0.27 mol) of methyl methacrylate were placed in a three-necked flask. 7.28 g (0.02 mol) of 2-(dodecyltrithiocarbonyl)-2-methylpropionic acid, 2.42 g of azobisisobutyronitrile, and 80 mL of anhydrous dioxane were added. The system was stirred until homogeneous, then purged with N2 for 20 min. The flask was sealed and placed in an oil bath set to 80 °C for the reaction. After 6 h of reaction, the reaction solution was poured into methanol, filtered, and dried to obtain product PMA2, ​​with a number-average molecular weight (Mn) of 1900 and a molecular weight distribution of 1.49. A 20 wt% dichloromethane solution of PMA2 was prepared.

[0048] 25.5 g of amino-terminated polydimethylsiloxane (PDMS) with Mn of 5000 was dissolved in 75 mL of dichloromethane (containing 0.011 mol of amino groups). The solution was stirred until homogeneous. Then, 50 mL of a 20 wt% dichloromethane solution of PMA2 (containing 0.033 mol of maleic anhydride groups) and 13.7 mL of a 20 wt% dichloromethane solution of 4,4'-diaminodiphenyl disulfide (containing 0.022 mol of amino groups) were quickly added. The mixture was stirred until homogeneous and then reacted at room temperature. The reaction was completed after approximately 1 hour. After removing the solvent, a room-temperature self-healing elastomer material, PDMS-E3, was obtained. The structure of the material is shown below. Figure 1 As shown, n in R1 is 66, x in R2 is 0.33 and y is 0.67. In the material, the weight fraction of R1 is 66.7%, the weight fraction of R2 is 26.1%, and the weight fraction of R3 is 7.2%.

[0049] Example 4

[0050] 7.84 g (0.08 mol) of maleic anhydride and 32.0 g (0.32 mol) of methyl methacrylate were placed in a three-necked flask. 1.46 g (0.004 mol) of 2-(dodecyltrithiocarbonyl)-2-methylpropionic acid, 0.51 g of azobisisobutyronitrile, and 100 mL of anhydrous dioxane were added. The system was stirred until homogeneous, then purged with N2 for 20 min. The flask was sealed and placed in an oil bath set to 80 °C for reaction. After 6 h of reaction, the reaction solution was poured into methanol, filtered, and dried to obtain product PMA3 with a number-average molecular weight (Mn) of 11800 and a molecular weight distribution of 1.24. A 20 wt% dichloromethane solution of PMA3 was prepared.

[0051] 25.5 g of amino-terminated polydimethylsiloxane (PDMS) with Mn of 5000 was dissolved in 75 mL of dichloromethane (containing 0.011 mol of amino groups). The mixture was stirred until homogeneous. Then, 50 mL of a 20 wt% dichloromethane solution of PMA3 (containing 0.033 mol of maleic anhydride groups) and 13.7 mL of a 20 wt% dichloromethane solution of 4,4'-diaminodiphenyl disulfide (containing 0.022 mol of amino groups) were quickly added. The mixture was stirred until homogeneous and then reacted at room temperature. The reaction was completed after approximately 1 hour. After removing the solvent, a room-temperature self-healing elastomer material, PDMS-E4, was obtained. The structure of the material is shown below. Figure 1 As shown, n in R1 is 66, x in R2 is 0.2 and y is 0.8. In the material, the weight fraction of R1 is 66.7%, the weight fraction of R2 is 26.1%, and the weight fraction of R3 is 7.2%.

[0052] Example 5

[0053] Prepare a 20wt% dichloromethane solution of PMA1 using the same method as in Example 1.

[0054] 12 g of amino-terminated polydimethylsiloxane (PDMS) with Mn of 3000 was dissolved in 75 mL of dichloromethane (containing 0.008 mol of amino groups). The solution was stirred until homogeneous. Then, 50 mL of a 20 wt% dichloromethane solution of PMA1 (containing 0.020 mol of maleic anhydride groups) and 7.5 mL of a 20 wt% dichloromethane solution of 4,4'-diaminodiphenyl disulfide (containing 0.012 mol of amino groups) were quickly added. The mixture was stirred until homogeneous and then reacted at room temperature. The reaction was completed after approximately 1 hour. After removing the solvent, a room-temperature self-healing elastomer material, PDMS-E5, was obtained. The structure of the material is shown below. Figure 1 As shown, n in R1 is 40, x in R2 is 0.2 and y is 0.8. In the material, the weight fraction of R1 is 51.1%, the weight fraction of R2 is 42.6%, and the weight fraction of R3 is 6.3%.

[0055] Example 6

[0056] Prepare a 20wt% dichloromethane solution of PMA4 using the same method as in Example 2.

[0057] 12 g of amino-terminated polydimethylsiloxane (PDMS) (Mn 3000) was dissolved in 75 mL of dichloromethane (containing 0.008 mol of amino groups). The solution was stirred until homogeneous. Then, 50 mL of a 20 wt% PMA4 solution (containing 0.020 mol of maleic anhydride groups) and 7.5 mL of a 20 wt% 4,4'-diaminodiphenyl disulfide dichloromethane solution (containing 0.012 mol of amino groups) were quickly added. The mixture was stirred until homogeneous and then reacted at room temperature. The reaction was completed after approximately 1 hour. After removing the solvent, a room-temperature self-healing elastomer material, PDMS-E6, was obtained. The structure of the material is shown below. Figure 2 As shown, n in R1 is 40, x in R2 is 0.2 and y is 0.8. In the material, the weight fraction of R1 is 51.1%, the weight fraction of R2 is 42.6%, and the weight fraction of R3 is 6.3%.

[0058] Example 7

[0059] Prepare a 20wt% dichloromethane solution of PMA1 using the same method as in Example 1.

[0060] 10 g of amino-terminated polydimethylsiloxane (PDMS) with Mn of 2000 was dissolved in 50 mL of dichloromethane (containing 0.01 mol of amino groups). The solution was stirred until homogeneous. Then, 50 mL of a 20 wt% dichloromethane solution of PMA1 (containing 0.020 mol of maleic anhydride groups) and 6.2 mL of a 20 wt% dichloromethane solution of 4,4'-diaminodiphenyl disulfide (containing 0.010 mol of amino groups) were quickly added. The mixture was stirred until homogeneous and then reacted at room temperature. The reaction was completed after approximately 1 hour. After removing the solvent, a room-temperature self-healing elastomer material, PDMS-E7, was obtained. The structure of the material is shown below. Figure 1 As shown, n in R1 is 25, x in R2 is 0.2 and y is 0.8. In the material, the weight fraction of R1 is 47.1%, the weight fraction of R2 is 47.1%, and the weight fraction of R3 is 5.8%.

[0061] Example 8

[0062] Prepare a 20wt% dichloromethane solution of PMA4 using the same method as in Example 2.

[0063] 10 g of amino-terminated polydimethylsiloxane (PDMS) (Mn = 2000) was dissolved in 50 mL of dichloromethane (containing 0.01 mol of amino groups). The solution was stirred until homogeneous. Then, 50 mL of a 20 wt% PMA4 solution in dichloromethane (containing 0.020 mol of maleic anhydride groups) and 6.2 mL of a 20 wt% 4,4'-diaminodiphenyl disulfide solution in dichloromethane (containing 0.01 mol of amino groups) were quickly added. The mixture was stirred until homogeneous and then reacted at room temperature. The reaction was completed after approximately 1 hour. After removing the solvent, a room-temperature self-healing elastomer material, PDMS-E8, was obtained. The structure of the material is shown below. Figure 2 As shown, n in R1 is 25, x in R2 is 0.2 and y is 0.8. In the material, the weight fraction of R1 is 47.1%, the weight fraction of R2 is 47.1%, and the weight fraction of R3 is 5.8%.

[0064] Comparative Example 1

[0065] Prepare a 20wt% dichloromethane solution of PMA1 using the same method as in Example 1.

[0066] 50 g of amino-terminated polydimethylsiloxane (PDMS) with Mn of 5000 was dissolved in 100 mL of dichloromethane (containing 0.020 mol of amino groups), stirred until homogeneous, and then 50 mL of a 20 wt% dichloromethane solution of PMA1 (containing 0.020 mol of maleic anhydride groups) was quickly added. After stirring until homogeneous, the reaction was carried out at room temperature. The reaction was stopped after about 1 hour, and the solvent was removed to obtain the elastomer material.

[0067] Comparative Example 2

[0068] Prepare a 20wt% dichloromethane solution of PMA1 using the same method as in Example 1.

[0069] 3 g of amino-terminated polydimethylsiloxane (PDMS) (Mn 600) was dissolved in 20 mL of dichloromethane (containing 0.01 mol of amino groups), and stirred until homogeneous. Then, 50 mL of a 20 wt% dichloromethane solution of PMA1 (containing 0.02 mol of maleic anhydride groups) and 6.2 mL of a 20 wt% dichloromethane solution of 4,4'-diaminodiphenyl disulfide (containing 0.01 mol of amino groups) were quickly added, stirred until homogeneous, and the reaction was carried out at room temperature. The reaction was stopped after approximately 1 hour, and the solvent was removed to obtain the elastomer material.

[0070] Comparative Example 3

[0071] 19.3 g (0.2 mol) of maleic anhydride and 20.2 g (0.2 mol) of methyl methacrylate were placed in a three-necked flask. 0.73 g (0.002 mol) of 2-(dodecyltrithiocarbonyl)-2-methylpropionic acid, 0.25 g of azobisisobutyronitrile, and 80 mL of anhydrous dioxane were added. The system was stirred until homogeneous, then purged with N2 for 20 min. The flask was sealed and placed in an oil bath set to 80 °C for reaction. After 8 h of reaction, the reaction solution was poured into methanol, filtered, and dried to obtain product PMA5, with a number-average molecular weight (Mn) of 21000 and a molecular weight distribution of 1.23. A 20 wt% dichloromethane solution of PMA5 was prepared.

[0072] 50 g of amino-terminated polydimethylsiloxane (PDMS) (Mn = 5000) was dissolved in 75 mL of dichloromethane (containing 0.02 mol of amino groups), and stirred until homogeneous. Then, 50 mL of a 20 wt% dichloromethane solution of PMA5 (containing 0.05 mol of maleic anhydride groups) and 18.6 mL of a 20 wt% dichloromethane solution of 4,4'-diaminodiphenyl disulfide (containing 0.03 mol of amino groups) were quickly added, stirred until homogeneous, and the reaction was carried out at room temperature. The reaction was stopped after approximately 1 hour, and the solvent was removed to obtain the elastomer material.

[0073] The raw material parameters for the synthesis of each embodiment and comparative example are shown in Table 1, and the material properties are shown in Table 2.

[0074] Table 1

[0075]

[0076]

[0077] Table 2

[0078]

[0079] As can be seen from Table 2, the fracture strength of the room temperature self-healing material of the present invention is 0.5-5 MPa, the fracture elongation is 100-800%, and it can be repaired at room temperature after fracture. The repair rate can reach more than 70% after 24 hours.

[0080] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A room-temperature self-healing polydimethylsiloxane elastomer material, characterized in that, The material is composed of a segment R1 containing a polydimethylsiloxane structure, a polymaleic anhydride copolymer structure R2, and a structure R3 containing an aromatic diamino disulfide. In the material, the weight fraction of R1 is 40-75%, the weight fraction of R2 is 20-55%, and the weight fraction of R3 is 3-15%. R1 is formed from a diamino-containing polydimethylsiloxane, wherein the number average molecular weight of the diamino-containing polydimethylsiloxane is 1000-10000; R2 is formed from a polymaleic anhydride copolymer, wherein the number average molecular weight of the polymaleic anhydride copolymer is 1000-20000; R3 is formed from a disulfide-containing aromatic diamine compound, wherein the disulfide-containing aromatic diamine compound is 4,4'-diaminodiphenyl disulfide or 2,2'-diaminodiphenyl disulfide.

2. The room-temperature self-healing polydimethylsiloxane elastomer material according to claim 1, wherein, In the material, the weight fraction of R1 is 45-70%, the weight fraction of R2 is 20-50%, and the weight fraction of R3 is 3-10%.

3. The method for preparing the room-temperature self-healing polydimethylsiloxane elastomer material according to claim 1 or 2, characterized in that, The preparation method includes: 1) Maleic anhydride is subjected to living radical polymerization with one or more monomers containing double bonds to obtain polymaleic anhydride copolymer, which is then prepared into a solution; 2) Prepare solutions of polydimethylsiloxane containing diamino groups and aromatic diamine compounds containing disulfides, respectively; 3) Mix the three solutions obtained in steps 1) and 2), react at room temperature, remove the solvent, and obtain room temperature self-healing polydimethylsiloxane elastomer material.

4. The method for preparing the room-temperature self-healing polydimethylsiloxane elastomer material according to claim 3, wherein, The monomer containing the double bond is selected from (meth)acrylate monomers and / or styrene monomers; the ratio of maleic anhydride to the monomer containing the double bond is 1:0.8-10.

5. The method for preparing room temperature self-healing polydimethylsiloxane elastomer material according to claim 4, wherein, The ratio of maleic anhydride to monomers containing double bonds is 1:1-6.

6. The method for preparing the room-temperature self-healing polydimethylsiloxane elastomer material according to any one of claims 3-5, wherein, The polymerization temperature in step 1) is 40-120℃; the polymerization time is 1-24h.

7. The method for preparing the room-temperature self-healing polydimethylsiloxane elastomer material according to claim 6, wherein, The polymerization temperature in step 1) is 50-120℃; the polymerization time is 2-16h.

8. The method for preparing room temperature self-healing polydimethylsiloxane elastomer material according to claim 3, wherein, The number average molecular weight of polymaleic anhydride copolymers is 1000-20000.

9. The method for preparing the room-temperature self-healing polydimethylsiloxane elastomer material according to claim 8, wherein, The number average molecular weight of polymaleic anhydride copolymers is 1500-15000.

10. The method for preparing the room-temperature self-healing polydimethylsiloxane elastomer material according to claim 3, wherein, The number-average molecular weight of the polydimethylsiloxane containing diamino groups is 1000-10000.

11. The method for preparing the room-temperature self-healing polydimethylsiloxane elastomer material according to claim 3, wherein, The disulfide-containing aromatic diamine compound is 4,4'-diaminodiphenyl disulfide or 2,2'-diaminodiphenyl disulfide.

12. The method for preparing room temperature self-healing polydimethylsiloxane elastomer material according to claim 3, wherein, The concentration of the solutions obtained in steps 1) and 2) is 10-30 wt%; the solvent used to prepare the solutions is selected from at least one of dichloromethane, trichloromethane, tetrahydrofuran, and dioxane.

13. The method for preparing the room-temperature self-healing polydimethylsiloxane elastomer material according to claim 3, wherein, In step 3), the amount of terminal amino groups in polydimethylsiloxane containing diamino groups is 0.20-0.60 mol per mole of maleic anhydride group in polymaleic anhydride copolymer; and the amount of diamine in aromatic diamine compound containing disulfide is 0.40-0.90 mol per mole of maleic anhydride group in polydimethylsiloxane containing diamino groups.

14. The method for preparing the room-temperature self-healing polydimethylsiloxane elastomer material according to claim 13, wherein, In step 3), the amount of terminal amino group in polydimethylsiloxane containing diamino group is 0.25-0.55 mol per mole of maleic anhydride group in polymaleic anhydride copolymer; and the amount of diamine in aromatic diamine compound containing disulfide is 0.45-0.80 mol per mole of maleic anhydride group in polydimethylsiloxane containing diamino group is 0.45-0.80 mol per mole of diamine group in polydimethylsiloxane.

15. The method for preparing room temperature self-healing polydimethylsiloxane elastomer material according to claim 3, wherein, The reaction time in step 3) is 0.1-12 hours.

16. The method for preparing the room-temperature self-healing polydimethylsiloxane elastomer material according to claim 15, wherein, The reaction time in step 3) is 0.2-8 hours.

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