Self-healing modified hydrogen-containing silicone oil and preparation method thereof
By introducing epoxy groups through the hydrosilylation reaction of polymethylhydrosilane with allyl glycidyl ether and utilizing the disulfide bonds in thioctic acid to form reversible dynamic covalent bonds, the phase separation problem of epoxy silicone oil is solved, improving self-healing efficiency and mechanical properties, making it suitable for demanding applications.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NAPA CHEM (SHANGHAI) CO LTD
- Filing Date
- 2026-04-30
- Publication Date
- 2026-05-29
AI Technical Summary
In epoxy-based silicone oils, the polarity of the organosilicon backbone and the epoxy groups is mismatched, leading to phase separation and affecting its mechanical properties. Furthermore, traditional modified silicone oils have low self-healing efficiency and insufficient mechanical recovery after healing.
By introducing epoxy groups through the hydrosilylation reaction of polymethylhydrosilane with allyl glycidyl ether and utilizing the disulfide bonds in thioctic acid to form reversible dynamic covalent bonds, a self-healing modified hydrogen-containing silicone oil is constructed, achieving both polarity uniformity and self-healing capability.
It improves the self-healing efficiency and mechanical properties of modified hydrogen-containing silicone oil, providing high reliability and long lifespan self-repair function, suitable for demanding applications such as flexible electronics, long-lasting corrosion protection and recyclable adhesives.
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Abstract
Description
Technical Field
[0001] This application relates to the field of silicone oil technology, and more specifically, to a self-healing modified hydrogen-containing silicone oil and its preparation method. Background Technology
[0002] Organosilicon materials, especially hydrogen-containing silicone oils whose main chain is composed of Si-O-Si bonds, exhibit a series of outstanding properties due to their unique molecular structure. Their extremely wide temperature range, excellent hydrophobic properties, and good physiological inertness have made them indispensable in many industrial and high-tech fields such as aerospace, electronics, and medical devices.
[0003] To further expand its functional boundaries, the introduction of epoxy groups into the side chains of hydrogen-containing silicone oils via hydrosilylation reactions to prepare epoxy-based silicone oils has become an important modification direction. This modification aims to combine the flexibility and thermal stability of the organosilicon backbone with the high reactivity and strong adhesion to the substrate of the epoxy groups, thereby obtaining new materials with more comprehensive properties.
[0004] However, the organosilicon backbone (Si-O-Si) in epoxy silicone oil is nonpolar, while the epoxy group is highly polar. The mismatch in polarity between the two groups easily leads to phase separation, so the cured film is prone to cracking, thus affecting the mechanical properties of epoxy silicone oil. Summary of the Invention
[0005] To improve the mechanical properties of epoxy-based silicone oils, this application provides a self-healing modified hydrogen-containing silicone oil and its preparation method.
[0006] In a first aspect, this application provides a method for preparing a self-healing modified hydrogen-containing silicone oil, employing the following technical solution: A method for preparing a self-healing modified hydrogen-containing silicone oil includes the following steps: (1) Mix 80-120 parts by weight of polymethylhydrosilane and 10-34 parts by weight of allyl glycidyl ether, heat to 90-120°C, add 1.5-10 ppm of platinum catalyst, stir and react for 2-4 hours to obtain intermediate reactant; (2) After 8 to 32 parts by weight of thioctic acid and 0.2 to 1 part by weight of ZnAA (zinc acetylacetone) are melted and mixed evenly at 130 to 140°C, they are added to the above intermediate reactants and stirred rapidly until homogeneous to obtain self-healing modified hydrogen-containing silicone oil.
[0007] By adopting the above technical solution, the first step is to modify polymethylhydrosilane with allyl glycidyl ether. The specific reaction principle is a platinum-catalyzed hydrosilylation reaction: under heating conditions, the platinum catalyst initiates the addition of the Si-H bond in the polymethylhydrosilane molecule to the C=C double bond at the end of the allyl glycidyl ether, so that the allyl glycidyl ether is grafted onto the siloxane backbone through a stable Si-C bond, thereby obtaining a hydrogen-containing silicone oil intermediate with epoxy groups.
[0008] The second step utilizes grafted epoxy groups as a "bridge," employing thioctic acid to undergo a ring-opening reaction with the epoxy groups on the intermediate reactants. This inserts reversible dynamic disulfide bonds into the intermediate reactants, reducing the difference between polar and non-polar components, resulting in a more uniform and stable structure for the modified hydrogen-containing silicone oil. Furthermore, the reversible breaking and recombination of disulfide bonds endows the modified hydrogen-containing silicone oil with self-healing capabilities, allowing it to repeatedly heal damage under mild conditions. Simultaneously, the dual network of "disulfide bonds (dynamic covalent) + hydrogen bonds" within the modified hydrogen-containing silicone oil enables synergistic energy dissipation and strength recovery, effectively addressing the issue of insufficient mechanical properties after healing.
[0009] Preferably, the polymethylhydrosilane has a hydrogen content of 0.002 to 0.005 mol / g and a molecular weight of 2000 to 10000.
[0010] Preferably, the polymethylhydrosilane has a hydrogen content of 0.004–0.005 mol / g and a molecular weight of 3600–4000.
[0011] By adopting the above technical solution, the intermediate reactant synthesized from polymethylhydrosilane and allyl glycidyl ether provides a suitable reaction site, making it easier to carry out the second step reaction, which is beneficial to improving the mechanical properties of the finally modified hydrogen-containing silicone oil after healing.
[0012] Preferably, the weight ratio of the polymethylhydrosilane to allyl glycidyl ether is 1:(0.125-0.35).
[0013] Preferably, the weight ratio of the polymethylhydrosilane to thioctic acid is 1:(0.125-0.42).
[0014] By adopting the above technical solution, the addition of polymethylhydrosilane, allyl glycidyl ether, intermediate reactants, and thioctic acid in the above weight ratio is beneficial to the efficient introduction of dynamic disulfide bonds and improves the conversion rate of self-healing modified hydrogen-containing silicone oil.
[0015] Secondly, this application provides a self-healing modified hydrogen-containing silicone oil, employing the following technical solution: A self-healing modified hydrogen-containing silicone oil is prepared by the above-mentioned method for preparing self-healing modified hydrogen-containing silicone oil.
[0016] The rise of dynamic covalent chemistry has driven the development of self-healing materials. Among these materials, disulfide bonds, due to their reversible breakage and recombination under stimuli such as heat and light, have become ideal dynamic units for constructing intrinsic self-healing systems. Lipoic acid, as a natural molecule containing both disulfide bonds and carboxyl groups, is considered an important module for introducing dynamic response properties.
[0017] By employing the above technical solution and using the "epoxy group bridging" strategy to precisely introduce thioctic acid dynamic units into the molecular chain of hydrogen-containing silicone oil, a self-healing modified silicone oil with a clear molecular structure and coordinated performance has been achieved. This design organically integrates the flexibility of organosilicon, the strong adhesion of epoxy resin, and the efficient dynamic reversibility of disulfide bonds. While maintaining the inherent temperature resistance, hydrophobicity, and stability of silicone oil, it effectively synergizes mechanical properties, interfacial adhesion, and self-healing capabilities. It overcomes the limitations of traditional modified silicone oils, such as easy phase separation, low self-healing efficiency, and insufficient mechanical recovery after healing. This provides a new material with high reliability, long lifespan, and self-repairing functions for demanding applications such as flexible electronics, long-lasting corrosion protection, and recyclable adhesives.
[0018] In summary, this application has the following beneficial effects: 1. Because this application precisely introduces the dynamic unit of thioctic acid into the molecular chain of hydrogen-containing silicone oil through the "epoxy group bridging" strategy, the synthesized self-healing modified hydrogen-containing silicone oil not only has the flexibility of organosilicon and the strong adhesion of epoxy resin, but also has the efficient dynamic reversibility of disulfide bonds, and has excellent self-healing ability, effectively improving the influence of phase separation of modified hydrogen-containing silicone oil on mechanical properties. 2. The preparation method of the self-healing modified hydrogen-containing silicone oil of this application involves first synthesizing silicone oil modified by allyl glycidyl ether. By adding thioctic acid to the product of the first step to generate silicone oil with reversible dynamic covalent bonds, the self-healing efficiency of the modified hydrogen-containing silicone oil can be improved. The preparation method is simple and easy to mass-produce. Detailed Implementation
[0019] The present application will be further described in detail below with reference to the embodiments.
[0020] Except as described below, all raw materials used in the embodiments of this application are commercially available;
[0021] Example 1 A self-healing modified hydrogen-containing silicone oil, the raw materials for its preparation and their corresponding weights (g) are shown in the table below.
[0022] Group raw materials Example 1 polymethylhydrosilane 80 Allyl glycidyl ether 10 0.1% platinum catalyst 0.15 Alpha-lipoic acid 9 ZnAA 0.2
[0023] The preparation method of the above-mentioned self-healing modified hydrogen-containing silicone oil includes the following steps: (1) After mixing polymethylhydrosilane and allyl glycidyl ether, heat to 120°C and add 0.1% platinum catalyst. Stir the reaction for 4 hours to obtain intermediate reactants.
[0024] In this embodiment, the polymethylhydrosilane has a hydrogen content of 0.002 mol / g and a molecular weight of 2000.
[0025] (2) After melting and mixing thioctic acid and ZnAA at 130°C, add them to the above intermediate reactants and stir rapidly until homogeneous for 0.5 h to obtain self-healing modified hydrogen-containing silicone oil.
[0026] Example 2 A self-healing modified hydrogen-containing silicone oil, the raw materials for its preparation and their corresponding weights (g) are shown in the table below.
[0027] Group raw materials Example 2 polymethylhydrosilane 100 Allyl glycidyl ether 22 0.1% platinum catalyst 0.2 Alpha-lipoic acid 20 ZnAA 0.5
[0028] The preparation method of the above-mentioned self-healing modified hydrogen-containing silicone oil includes the following steps: (1) After mixing polymethylhydrosilane and allyl glycidyl ether, heat to 120°C and add 0.1% platinum catalyst. Stir the reaction for 4 hours to obtain intermediate reactants.
[0029] In the embodiments of this application, the hydrogen content of polymethylhydrosilane is 0.004 mol / g and the molecular weight is 5000.
[0030] (2) After melting and mixing thioctic acid and ZnAA at 140°C, add them to the above intermediate reactants and stir rapidly until homogeneous for 1 hour to obtain self-healing modified hydrogen-containing silicone oil.
[0031] Example 3 A self-healing modified hydrogen-containing silicone oil, the raw materials for its preparation and their corresponding weights (g) are shown in the table below.
[0032] Group raw materials Example 3 polymethylhydrosilane 100 Allyl glycidyl ether 35 0.1% platinum catalyst 0.5 Alpha-lipoic acid 40 ZnAA 0.8
[0033] The preparation method of the above-mentioned self-healing modified hydrogen-containing silicone oil includes the following steps: (1) After mixing polymethylhydrosilane and allyl glycidyl ether, heat to 120°C and add 0.1% platinum catalyst. Stir the reaction for 4 hours to obtain intermediate reactants.
[0034] In this embodiment, the polymethylhydrosilane has a hydrogen content of 0.005 mol / g and a molecular weight of 3600.
[0035] (2) After melting and mixing thioctic acid and ZnAA at 130°C, add them to the above intermediate reactants and stir rapidly until homogeneous for 1 hour to obtain self-healing modified hydrogen-containing silicone oil.
[0036] Example 4 A self-healing modified hydrogen-containing silicone oil, the raw materials for its preparation and their corresponding weights (g) are shown in the table below.
[0037] Group raw materials Example 4 polymethylhydrosilane 100 Allyl glycidyl ether 35 0.1% platinum catalyst 35 Alpha-lipoic acid 20 ZnAA 0.6
[0038] The preparation method of the above-mentioned self-healing modified hydrogen-containing silicone oil includes the following steps: (1) After mixing polymethylhydrosilane and allyl glycidyl ether, heat to 120°C and add 0.1% platinum catalyst. Stir the reaction for 4 hours to obtain intermediate reactants.
[0039] In the embodiments of this application, the hydrogen content of polymethylhydrosilane is 0.005 mol / g, and the molecular weight is 4000.
[0040] (2) After melting and mixing thioctic acid and ZnAA at 130°C, add them to the above intermediate reactants and stir rapidly until homogeneous for 1.5 h to obtain self-healing modified hydrogen-containing silicone oil.
[0041] Example 5 A self-healing modified hydrogen-containing silicone oil, the raw materials for its preparation and their corresponding weights (g) are shown in the table below.
[0042] Group raw materials Example 5 polymethylhydrosilane 120 Allyl glycidyl ether 28 0.1% platinum catalyst 0.3 Alpha-lipoic acid 50 ZnAA 0.8
[0043] The preparation method of the above-mentioned self-healing modified hydrogen-containing silicone oil includes the following steps: (1) After mixing polymethylhydrosilane and allyl glycidyl ether, heat to 120°C and add 0.1% platinum catalyst. Stir the reaction for 4 hours to obtain intermediate reactants.
[0044] In this embodiment, the polymethylhydrosilane has a hydrogen content of 0.004 mol / g and a molecular weight of 4000.
[0045] (2) After melting and mixing thioctic acid and ZnAA at 140°C, add them to the above intermediate reactants and stir rapidly until homogeneous for 1 hour to obtain self-healing modified hydrogen-containing silicone oil.
[0046] Comparative Example 1 A modified hydrogen-containing silicone oil, which differs from Example 1 in that the amount of zinc sulfate and ZnAA added is 0.
[0047] The preparation method of the above-mentioned modified hydrogen-containing silicone oil includes the following steps: After mixing polymethylhydrosilane and allyl glycidyl ether, the mixture was heated to 120°C, and 0.1% platinum catalyst was added. The mixture was stirred for 4 hours to obtain an intermediate reactant.
[0048] The polymethylhydrosilane contains 0.002 mol / g of hydrogen and has a molecular weight of 2000.
[0049] Comparative Example 2 A modified hydrogen-containing silicone oil, which differs from Example 2 in that the amount of zinc sulfate and ZnAA added is 0.
[0050] The preparation method of the above-mentioned self-healing modified hydrogen-containing silicone oil includes the following steps: After mixing polymethylhydrosilane and allyl glycidyl ether, the mixture was heated to 120°C, and 0.1% platinum catalyst was added. The mixture was stirred for 4 hours to obtain an intermediate reactant.
[0051] The polymethylhydrosilane contains 0.004 mol / g of hydrogen and has a molecular weight of 5000.
[0052] Comparative Example 3 A modified hydrogen-containing silicone oil, which differs from Example 3 in that the amount of zinc sulfate and ZnAA added is 0.
[0053] The preparation method of the above-mentioned self-healing modified hydrogen-containing silicone oil includes the following steps: After mixing polymethylhydrosilane and allyl glycidyl ether, the mixture was heated to 120°C, and 0.1% platinum catalyst was added. The mixture was stirred for 4 hours to obtain an intermediate reactant.
[0054] The polymethylhydrosilane contains 0.005 mol / g of hydrogen and has a molecular weight of 3600.
[0055] Comparative Example 4 A modified hydrogen-containing silicone oil, which differs from Example 4 in that the amount of zinc sulfate and ZnAA added is 0.
[0056] The preparation method of the above-mentioned self-healing modified hydrogen-containing silicone oil includes the following steps: After mixing polymethylhydrosilane and allyl glycidyl ether, the mixture was heated to 120°C, and 0.1% platinum catalyst was added. The mixture was stirred for 4 hours to obtain an intermediate reactant.
[0057] The polymethylhydrosilane contains 0.005 mol / g of hydrogen and has a molecular weight of 4000.
[0058] Comparative Example 5 A modified hydrogen-containing silicone oil, which differs from Example 5 in that the amount of zinc sulfate and ZnAA added is 0.
[0059] The preparation method of the above-mentioned self-healing modified hydrogen-containing silicone oil includes the following steps: After mixing polymethylhydrosilane and allyl glycidyl ether, the mixture was heated to 120°C, and 0.1% platinum catalyst was added. The mixture was stirred for 4 hours to obtain an intermediate reactant.
[0060] The polymethylhydrosilane contains 0.004 mol / g of hydrogen and has a molecular weight of 4000.
[0061] Performance testing The silicone oils prepared in Examples 1-5 and Comparative Examples 1-5 were subjected to photocuring and then their mechanical properties, self-healing properties, interfacial adhesion, and synergistic evaluation of self-healing were performed. The test methods are as follows: 1. Photopolymerization molding solution Add 3% cationic photoinitiator (Irgacure 250) to 100g of silicone oil, and irradiate with 365nm wavelength ultraviolet light (light intensity 200 mW / cm²) for 180 seconds to rapidly crosslink at room temperature to form a three-dimensional skeleton mainly composed of epoxy-polyether network, thereby fixing the macroscopic shape of the material and obtaining a molded part. Subsequently, the molded part is placed in an 80℃ oven for 4 hours of heat post-treatment to fully activate the dynamic disulfide bonds in the thioctic acid unit. A second dynamic covalent network is constructed through ring-opening polymerization and exchange reaction, and finally a multifunctional self-healing elastomer (a sheet with a thickness of 2mm) is obtained, which combines the rigidity of epoxy network, the flexibility of organosilicon segments, and the dynamic reversibility of disulfide bonds.
[0062] 2. Synergistic evaluation of mechanical properties and self-healing efficiency Referring to GB / T 528-2009 standard, self-healing elastomers were prepared into standard dumbbell-shaped tensile specimens (Type I, with the narrow portion measuring 33mm long × 6mm wide × 2mm thick). A controlled incision (3mm in length, perpendicularly penetrating the center of the narrow portion of the specimen, to a depth of half the thickness) was made using a new blade. Tensile testing was then performed according to GB / T 528-2009 standard (tensile speed 500mm / min). After tensile fracture, the fracture site was clamped between two small glass plates, and both ends were fixed with clips. The specimens were then placed at 80℃ for 4 hours for post-healing tensile testing.
[0063] 3. Synergistic evaluation of interfacial adhesion and self-healing Self-healing elastomer was used as an adhesive to bond metal-to-metal (type 6061) specimens. The specimens were stretched at 13 mm / min until complete separation. After shear strength testing of the bonded specimens according to GB / T 7124-2008, the fractured interfaces were realigned, the fractured section of the specimen was clamped with two small glass plates, and both ends were fixed with clips. The specimens were then placed at 80°C for 4 hours to allow healing before testing their shear strength again.
[0064] 4. Test Results (1) The test results of the synergistic evaluation of mechanical properties and self-healing efficiency are shown in Table 1: Table 1. Results of the combined test of mechanical properties and self-healing efficiency Test Project Group Tensile strength (MPa) Elongation at break (%) Tensile strength after healing (MPa) Strength healing efficiency (%) Elongation at break after healing (%) Elongation at break healing efficiency (%) Example 1 3.5 245.4 2.8 80.0 210.6 85.8 Example 2 5.1 501.3 4.7 92.2 453.7 90.5 Example 3 7.7 358.5 7.2 93.5 345.6 96.4 Example 4 7.2 248.8 6.3 87.5 227.7 91.5 Example 5 5.4 612.7 5.0 92.6 586.4 95.7 Comparative Example 1 6.0 56.6 0.3 5.0 3.3 5.8 Comparative Example 2 7.9 59.3 0.4 5.1 3.7 6.2 Comparative Example 3 10.3 47.2 0.3 2.9 3.2 6.8 Comparative Example 4 9.0 67.8 0.4 4.4 5.0 7.4 Comparative Example 5 7.5 89.1 0.4 5.3 6.0 6.7
[0065] (2) The results of the synergistic evaluation test of interfacial adhesion and self-healing are shown in Table 2: Table 2. Results of the synergistic test of interfacial adhesion and self-healing efficiency Test Project Group Bond strength (MPa) Post-healing bond strength (MPa) Recovery rate of bond strength after healing (%) Example 1 3.5 2.9 82.9 Example 2 4.7 4.3 91.5 Example 3 7.5 7.1 94.7 Example 4 6.7 5.7 85.1 Example 5 5.8 5.4 93.1 Comparative Example 1 5.7 0.5 8.8 Comparative Example 2 7.3 0.3 4.1 Comparative Example 3 8.2 0.4 4.9 Comparative Example 4 8.6 0.3 3.5 Comparative Example 5 6.9 0.2 2.9
[0066] As can be seen from the test results in Tables 1 and 2, all examples that introduced the lipoic acid dynamic network successfully achieved efficient self-healing function, with healing efficiencies of tensile strength and adhesive strength generally reaching 80% to 95% or more, which is significantly better than the control example (efficiency <10%) which has almost no healing ability.
[0067] Among them, Examples 3 and 5 showed the best performance, achieving a healing efficiency of over 90% while maintaining high mechanical strength (tensile strength 7.7 MPa, adhesive strength 7.5 MPa), demonstrating excellent balance between rigidity and toughness and self-healing properties; the latter exhibited extreme ductility (elongation at break 612.7%) and high healing efficiency (95.7%), highlighting the super toughness endowed by the dynamic network.
[0068] Furthermore, the adhesive strength recovery rate of the modified materials in the implementation group was generally higher than that in the control group, verifying that the self-healing modified hydrogen-containing silicone oil of the present invention is a multifunctional smart material with high strength, high adhesion and excellent self-healing ability.
[0069] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.
Claims
1. A method for preparing a self-healing modified hydrogen-containing silicone oil, characterized in that, Includes the following steps: (1) After mixing polymethylhydrosilane and allyl glycidyl ether, heat to 90-120°C, add platinum catalyst, and stir for 2-4 hours to obtain intermediate reactant; (2) After melting and mixing thioctic acid and ZnAA at 130-140℃, add them to the above intermediate reactants and stir quickly until homogeneous to obtain self-healing modified hydrogen-containing silicone oil.
2. The method for preparing the self-healing modified hydrogen-containing silicone oil according to claim 1, characterized in that, Includes the following steps: (1) Mix 80-120 parts by weight of polymethylhydrosilane and 10-34 parts by weight of allyl glycidyl ether, heat to 90-120°C, add platinum catalyst, stir and react for 2-4 hours to obtain intermediate reactant; (2) After 8-32 parts by weight of thioctic acid and 0.2-1 parts by weight of ZnAA are melted and mixed evenly at 130-140°C, they are added to the above intermediate reactants and stirred rapidly until homogeneous to obtain self-healing modified hydrogen-containing silicone oil.
3. The method for preparing the self-healing modified hydrogen-containing silicone oil according to claim 1 or 2, characterized in that, The polymethylhydrosilane has a hydrogen content of 0.002–0.005 mol / g and a molecular weight of 2000–10000.
4. The method for preparing the self-healing modified hydrogen-containing silicone oil according to claim 3, characterized in that, The polymethylhydrosilane has a hydrogen content of 0.004–0.005 mol / g and a molecular weight of 3600–4000.
5. The method for preparing the self-healing modified hydrogen-containing silicone oil according to claim 3, characterized in that, The weight ratio of the polymethylhydrosilane to allyl glycidyl ether is 1:(0.125-0.35).
6. The method for preparing the self-healing modified hydrogen-containing silicone oil according to claim 5, characterized in that, The weight ratio of the polymethylhydrosilane to allyl glycidyl ether is 1:(0.23-0.35).
7. The method for preparing the self-healing modified hydrogen-containing silicone oil according to claim 3, characterized in that, The weight ratio of the polymethylhydrosilane to thioctic acid is 1:(0.125-0.42).
8. The method for preparing the self-healing modified hydrogen-containing silicone oil according to claim 7, characterized in that, The weight ratio of the polymethylhydrosilane to thioctic acid is 1:(0.4 to 0.42).
9. A self-healing modified hydrogen-containing silicone oil, characterized in that, It is prepared by the method described in any one of claims 1 to 8 for preparing self-healing modified hydrogen-containing silicone oil.