Self-repairing polyurethane microcapsules, and methods of making and using the same
By introducing polyisocyanates and oligomeric polyols into polyurethane microcapsules, and combining dynamic disulfide bonds and shape memory properties, the problem of self-closing of curved surface cracks in polyurethane microcapsules was solved, achieving a self-healing effect under heating conditions, simplifying the preparation process and reducing costs.
Patent Information
- Application Number
- CN202411532253.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-30
- Publication Date
- 2025-12-09
- Estimated Expiration
- 2044-10-30
AI Technical Summary
Existing polyurethane microcapsules are difficult to close autonomously after being damaged by curved surface cracks, which affects the physicochemical properties of the core material and results in insufficient self-healing performance.
Microcapsules were prepared by introducing polyisocyanates and oligomeric polyols. By combining dynamic disulfide bonds and shape memory properties, the self-healing of microcapsules was achieved by utilizing the diffusion rearrangement of polyurethane molecular chains. The structure of soft and hard segments was regulated to control the self-healing performance.
Under heating conditions, microcapsules can restore their original shape before damage, achieve autonomous closure, and realize adaptive repair of damage. Moreover, the preparation method is simple and low-cost.
Smart Images
Figure QLYQS_1 
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Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of new materials, in particular to a self-repairing polyurethane microcapsule and a preparation method and application thereof. BACKGROUND
[0002] Microcapsule is a kind of micro-particle composed of natural or synthetic polymer (wall material) wrapping a certain object (core material). The wall material separates the core material from the external medium (such as light, oxygen and water, etc.), so as to protect the original physical and chemical properties of the core material, improve the stability of the core material and prolong the shelf life of the product, etc. By adjusting the wall material, core material and preparation method, microcapsules with different structures and properties can be prepared to meet different application requirements. Since Green's pioneering research in 1955, microcapsules have attracted great attention and have been widely used in food processing, textiles, biomedicine, agriculture, electronics and construction, etc. For example, they are used to prepare phase change energy storage materials, self-repairing materials and photosensitive materials, etc. Polyurethane is one of the most widely used polymer materials. Due to the variety of raw materials, diverse synthesis process and processing method, and wide range of adjustable structure and performance, polyurethane products are rich in types and have been successfully used to prepare various microcapsule materials.
[0003] However, during the application process, polyurethane microcapsules will inevitably be damaged to varying degrees by physical or chemical damage, thereby affecting the physical and chemical properties of the core material. If self-repairing performance is given to polyurethane microcapsules, the problem can be effectively solved. So far, there have been few reports on self-repairing polyurethane microcapsules, which is mainly related to the shape and structure of the microcapsules. Microcapsules have different shapes, and the core material they cover is liquid in most cases, which is spherical. This spherical shape is a curved surface structure, and the curved surface has radial load and certain curvature. When damaged by external force, cracks appear on the microcapsule shell and the microcapsule deforms due to the shearing effect of external force. Unlike planar cracks, this deformation makes the curved surface crack unable to close, which brings great challenges to the self-repair of the microcapsule itself. Therefore, how to make the curved surface crack of the microcapsule self-close is a key problem for the microcapsule to realize self-repairing performance. SUMMARY
[0004] In view of the above problems, the present application provides a self-repairing polyurethane microcapsule which can restore the shape before damage under heating conditions, so as to facilitate the self-adaptive repair of the damage.
[0005] In order to achieve the above purpose, the present application provides a self-repairing polyurethane microcapsule, which is mainly prepared from the following raw materials in weight ratio:
[0006]
[0007] The shape memory property of the polymer refers to the ability of the polymer to restore a predetermined shape under certain conditions. After the shape memory material is deformed under certain conditions, it can restore to the initial shape set in advance under certain external stimuli (such as temperature, light, humidity, pH value or electric field, etc.). Based on this, the present inventors propose to prepare microcapsules with polyisocyanate and oligomer polyol as main raw materials. By using polyisocyanate as a hard segment and oligomer polyol as a soft segment, the soft and hard segment structures are introduced into the polyurethane molecular structure, which endows the microcapsules with shape memory properties, so that they can realize self-closing of the wound under certain conditions after being damaged, and then repair the damage through the diffusion and rearrangement of the polyurethane molecular chain and the dynamic covalent bond or non-covalent bond at the wound site. At the same time, by introducing dynamic disulfide bonds into the molecular structure through disulfide compounds, the self-repairing property of the microcapsules is endowed, and at the same time, as a chain extender, the disulfide compounds participate in the reaction to adjust the soft and hard segment structures and further control the shape memory property. The operator can also control the number and density of disulfide bonds and hydrogen bonds by adjusting the disulfide compounds to realize the controllable structure and performance.
[0008] In one embodiment, the oligomer polyol includes at least one of polycaprolactone diol, polycarbonate diol, polytetrahydrofuran diol, polypropylene oxide diol, or polypropylene oxide triol.
[0009] In one embodiment, the polyisocyanate includes at least one of isophorone diisocyanate, 1,6-hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane-4,4'-diisocyanate, xylylene diisocyanate, methylcyclohexyl diisocyanate, tetramethylxylylene diisocyanate, HDI trimer, isophorone diisocyanate trimer, TDI trimer, or MDI trimer.
[0010] The HDI trimer is also known as hexamethylene diisocyanate trimer, the TDI trimer is also known as toluene diisocyanate trimer, and the MDI trimer is also known as hexamethylene diisocyanate trimer.
[0011] In one embodiment, the surfactant includes at least one of sodium dodecyl sulfate, gum arabic, cetyltrimethylammonium bromide, sodium dodecylbenzenesulfonate, or sodium alginate.
[0012] In one embodiment, the core material includes at least one of n-tetradecane, n-octadecane, n-heptadecane, or eicosane.
[0013] In one embodiment, the disulfide includes at least one of 2-hydroxyethyl disulfide, 4,4-dithiodiyl bis(4,1-phenylene) dimethanol, dithioglycolic acid, 2,2-dithiodipropionic acid, or bis(4-hydroxyphenyl) disulfide.
[0014] In one of the embodiments, the solvent includes at least one of chloroform, ethyl acetate, dichlorobenzene, chlorobenzene.
[0015] The application further provides a preparation method of the self-repairing polyurethane microcapsule, including the following steps:
[0016] Preparation of polyurethane prepolymer: heating, dehydrating, cooling, adding polyisocyanate, and performing polymerization to obtain the polyurethane prepolymer;
[0017] Preparation of polyurethane microcapsule: mixing and stirring the surfactant and water to obtain a surfactant solution, dissolving the polyurethane prepolymer and the core material in the solvent to obtain a mixed solution, mixing the mixed solution and the surfactant solution, stirring, adding the disulfide compound, and performing reaction to obtain the polyurethane microcapsule.
[0018] In one of the embodiments, the preparation of the polyurethane microcapsule further includes filtering, washing, and drying after the reaction step.
[0019] In one of the embodiments, in the preparation of the polyurethane prepolymer, the oligomer polyol is heated to 100-130 DEG C, dehydrated under a vacuum degree of greater than or equal to 0.08 MPa for 2-3 h, cooled to below 60 DEG C, polyisocyanate is added, and polymerization is performed at 70-95 DEG C for 2-5 h to obtain the polyurethane prepolymer.
[0020] In the preparation of the polyurethane microcapsule, the surfactant and water are mixed and stirred for 0.5-3 h to obtain a surfactant solution, the polyurethane prepolymer and the core material are dissolved in the solvent to obtain a mixed solution, the mixed solution and the surfactant solution are mixed and stirred for 0.5-2 h, the disulfide compound is added, and reaction is performed for 10-24 h to obtain the polyurethane microcapsule.
[0021] The application further provides an application of the self-repairing polyurethane microcapsule in phase change energy storage materials, self-repairing materials, and photosensitive materials.
[0022] Compared with the prior art, the application has the following beneficial effects:
[0023] The self-repairing polyurethane microcapsule, the preparation method and the application thereof have the following advantages: after deformation and damage, the self-repairing polyurethane microcapsule can restore the original curved shape of the raw material under heating conditions, and thus can achieve self-adaptive repair. The raw materials involved in the preparation method are cheap and easy to obtain, the synthesis process does not require special conditions and equipment, the synthesis process is easy to control, and the raw materials involved are already industrial products in large quantities, so the process is simple and the cost is low. BRIEF DESCRIPTION OF DRAWINGS
[0024] Figure 1A scanning electron microscope image of the self-repairing polyurethane microcapsule morphology in Example 1;
[0025] Figure 2 A scanning electron microscope image of the self-repairing polyurethane microcapsule after being cut in Example 1;
[0026] Figure 3 A scanning electron microscope image of the self-repairing polyurethane microcapsule after being heated to restore the original shape in Example 1;
[0027] Figure 4 A scanning electron microscope image of the self-repairing polyurethane microcapsule in Example 1. DETAILED DESCRIPTION
[0028] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the accompanying drawings. The preferred embodiments of the present application are shown in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to make the disclosure of the present application more thorough and comprehensive.
[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terminology used in the specification of the present application herein is only for the purpose of describing specific embodiments and is not intended to limit the present application.
[0030] Source:
[0031] The reagents, materials, and equipment used in this example are commercially available unless otherwise specified. The test methods are conventional test methods in the art unless otherwise specified.
[0032] Example 1
[0033] A self-repairing polyurethane microcapsule and a method for preparing the same.
[0034] 1. Preparation of a self-repairing polyurethane microcapsule.
[0035] (1) Preparation of a polyurethane prepolymer.
[0036] 60 parts of polycaprolactone diol (oligomeric polyol) were heated to 130°C, and dehydrated for 2 hours under a vacuum of 0.08 MPa or more, and then the temperature was lowered to below 60°C. Then, 10 parts of 1,6-hexamethylene diisocyanate (polyisocyanate) was added, and the reaction system was reacted at 95°C for 2 hours to obtain a polyurethane prepolymer.
[0037] (2) Preparation of a polyurethane microcapsule.
[0038] The polyurethane microcapsule was prepared by the following steps: 50 parts of arabic gum (surfactant) and 600 parts of deionized water were reacted for 0.5 hour under stirring at room temperature to obtain a surfactant solution, the above polyurethane prepolymer, 10 parts of n-tetradecane (core material) were dissolved in 50 parts of chlorobenzene (solvent) to obtain a mixed solution, the mixed solution was added to the surfactant solution and stirred for 0.5 hour, then 1 part of 2-hydroxyethyl disulfide (disulfide compound) was added and reacted for 24 hours, finally the polyurethane microcapsule was obtained by filtration, repeated washing with deionized water for 2 times, and air drying at room temperature for 48 hours.
[0039] 2. Test of self-repairing performance of the polyurethane microcapsule.
[0040] The polyurethane microcapsule prepared in Example 1 has a spherical shape as shown in Figure 1 . The polyurethane microcapsule was cut open with a blade, and it was found that the microcapsule was deformed under the shearing force Figure 2 . The damaged microcapsule was heated in an oven at 60°C for 10 hours, and it was found that the deformed microcapsule had recovered to the original curved shape Figure 3 . Further extending the heating time to 24 hours, the damaged microcapsule was completely repaired Figure 4 .
[0041] Example 2
[0042] A self-repairing polyurethane microcapsule and a preparation method thereof.
[0043] 1. Preparation of the self-repairing polyurethane microcapsule.
[0044] (1) Preparation of the polyurethane prepolymer.
[0045] 40 parts of polycaprolactone diol (oligomer polyol) were heated to 100°C, and dehydrated for 3 hours under vacuum at a vacuum degree of 0.08 MPa or above, then the temperature was reduced to below 60°C; then, 50 parts of 1,6-hexamethylene diisocyanate (polyisocyanate) was added, and the reaction system was reacted for 5 hours at 70°C to obtain the polyurethane prepolymer.
[0046] (2) Preparation of the polyurethane microcapsule.
[0047] 70 parts of arabic gum (surfactant) and 600 parts of deionized water were reacted for 3 hours under stirring at room temperature to obtain a surfactant solution, the above polyurethane prepolymer, 40 parts of n-tetradecane (core material) were dissolved in 30 parts of chlorobenzene (solvent) to obtain a mixed solution, the mixed solution was added to the surfactant solution and stirred for 2 hours, then 10 parts of 2-hydroxyethyl disulfide (disulfide compound) was added and reacted for 10 hours, finally the polyurethane microcapsule was obtained by filtration, repeated washing with deionized water for 5 times, and air drying at room temperature for 24 hours.
[0048] 2. Test of self-repairing performance of polyurethane microcapsules.
[0049] The polyurethane microcapsules prepared in Example 2 were spherical. The polyurethane microcapsules were cut open with a blade, and the microcapsules were deformed. The damaged microcapsules were heated in an oven at 60°C for 10 hours, and the microcapsules returned to the original curved shape. The heating time was further extended to 24 hours, and the damaged microcapsules were completely repaired.
[0050] Example 3
[0051] A self-repairing polyurethane microcapsule and a preparation method thereof.
[0052] 1. Preparation of self-repairing polyurethane microcapsules
[0053] (1) Preparation of polyurethane prepolymer
[0054] 50 parts of polytetrahydrofuran diol (oligomer polyol) were heated to 120°C, and dehydrated for 3 hours under a vacuum degree of 0.08 MPa or more. Then, the temperature was reduced to below 60°C. Then, 50 parts of isophorone diisocyanate (polyisocyanate) were added, and the reaction system was reacted at 85°C for 3 hours to obtain the polyurethane prepolymer.
[0055] (2) Preparation of polyurethane microcapsules
[0056] 50 parts of sodium dodecyl sulfate (surfactant) and 600 parts of deionized water were reacted for 2 hours under stirring at room temperature to obtain a surfactant solution. The polyurethane prepolymer, 20 parts of n-eicosane (core material), and 40 parts of ethyl acetate (solvent) were dissolved to obtain a mixed solution. The mixed solution was added to the surfactant solution and stirred for 1 hour. Then, 5 parts of 4,4-dithiodiyl bis (4,1-phenylene) dimethanol (disulfide compound) was added and reacted for 12 hours. Finally, the product was filtered, washed with deionized water for 4 times, and air-dried at room temperature for 24 hours to obtain the polyurethane microcapsules.
[0057] 2. Test of self-repairing performance of polyurethane microcapsules.
[0058] The polyurethane microcapsules prepared in Example 3 were spherical. The polyurethane microcapsules were cut open with a blade, and the microcapsules were deformed. The damaged microcapsules were heated in an oven at 60°C for 10 hours, and the microcapsules returned to the original curved shape. The heating time was further extended to 24 hours, and the damaged microcapsules were completely repaired.
[0059] Example 4
[0060] A self-repairing polyurethane microcapsule and a preparation method thereof.
[0061] 1. Preparation of self-repairing polyurethane microcapsules
[0062] (1) Preparation of polyurethane prepolymer.
[0063] 45 parts of polytetrahydrofuran diol (oligomer polyol) was heated to 120°C, and dehydrated for 3 hours under a vacuum of 0.08 MPa or more, and then the temperature was lowered to 60°C or less. Then, 30 parts of diphenylmethane-4,4'-diisocyanate (polyisocyanate) was added, and the reaction system was reacted for 3 hours at 90°C to obtain a polyurethane prepolymer.
[0064] (2) Preparation of polyurethane microcapsule.
[0065] 60 parts of gum arabic (surfactant) and 600 parts of deionized water were reacted for 1 hour under stirring at room temperature to obtain a surfactant solution. The polyurethane prepolymer, 30 parts of n-tetradecane (core material), and 50 parts of ethyl acetate (solvent) were dissolved to obtain a mixed solution. The mixed solution was added to the surfactant solution and stirred for 1 hour, and then 6 parts of 4,4-dithiodiyl bis (4,1-phenylene) dimethanol (dithio compound) was added and reacted for 10 hours. Finally, the product was filtered, washed with deionized water for 3 times, and air-dried at room temperature for 24 hours to obtain a polyurethane microcapsule.
[0066] 2. Test of self-repairing performance of polyurethane microcapsule.
[0067] The polyurethane microcapsule prepared in Example 4 was spherical. The polyurethane microcapsule was cut open with a blade, and the microcapsule was deformed. The damaged microcapsule was heated in a 60°C oven for 10 hours, and the microcapsule recovered to the original curved shape. Further extending the heating time to 24 hours, the damaged microcapsule was completely repaired.
[0068] The technical features of the above-described embodiments can be combined in any manner. For the sake of brevity, not all possible combinations of the technical features in the above-described embodiments are described, however, as long as the combinations of the technical features do not contradict each other, they should be considered within the scope of the present disclosure.
[0069] The above-described embodiments only express several embodiments of the present disclosure, and the description is more specific and detailed, but it should not be understood as limiting the scope of the patent. It should be noted that for those skilled in the art, without departing from the concept of the present disclosure, a number of modifications and improvements can be made, which are within the scope of the present disclosure. Therefore, the scope of protection of the present patent should be subject to the appended claims.
Claims
1. Self-repairing polyurethane microcapsules, characterized in that, It is prepared mainly by the following raw materials in weight ratio: The disulfide includes at least one of 2-hydroxyethyl disulfide, 4,4-dithiobis(4,1-phenylene) dimethanol, dithio glycolic acid, 2,2-dithiodipropionic acid, and bis(4-hydroxyphenyl) disulfide; The preparation method of the self-repairing polyurethane microcapsule includes the following steps: Preparation of polyurethane prepolymer: heat the oligomer polyol, dehydrate, cool down, add polyisocyanate, and carry out polymerization reaction to obtain polyurethane prepolymer; Preparation of polyurethane microcapsule: mix the surfactant and water, stir to obtain a surfactant solution, dissolve the polyurethane prepolymer and the core material in a solvent to obtain a mixed solution, mix the mixed solution and the surfactant solution, stir, add a disulfide compound, and carry out reaction to obtain polyurethane microcapsule.
2. The self-repairing polyurethane microcapsules according to claim 1, characterized in that, The oligomer polyol includes at least one of polycaprolactone diol, polycarbonate diol, polytetrahydrofuran diol, polypropylene oxide diol, or polypropylene oxide triol.
3. The self-repairing polyurethane microcapsule according to claim 1, wherein, The polyisocyanate includes at least one of isophorone diisocyanate, 1,6-hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane-4,4'-diisocyanate, xylylene diisocyanate, methylcyclohexyl diisocyanate, tetramethylxylylene diisocyanate, HDI trimer, isophorone diisocyanate trimer, TDI trimer, or MDI trimer.
4. The self-repairing polyurethane microcapsule according to claim 1, wherein, The surfactant includes at least one of sodium dodecyl sulfate, gum arabic, cetyltrimethylammonium bromide, sodium dodecylbenzenesulfonate, or sodium alginate.
5. The self-repairing polyurethane microcapsule according to claim 1, wherein, The core material includes at least one of n-tetradecane, n-octadecane, n-heptadecane, or eicosane.
6. The self-repairing polyurethane microcapsule according to claim 1, wherein, The solvent includes at least one of chloroform, ethyl acetate, dichlorobenzene, or chlorobenzene.
7. Process for the preparation of self-repairing polyurethane microcapsules according to any one of claims 1 to 6, characterized in that, It includes the following steps: Preparation of polyurethane prepolymer: heat the oligomer polyol, dehydrate, cool down, add polyisocyanate, and carry out polymerization reaction to obtain polyurethane prepolymer; Preparation of polyurethane microcapsule: mix the surfactant and water, stir to obtain a surfactant solution, dissolve the polyurethane prepolymer and the core material in a solvent to obtain a mixed solution, mix the mixed solution and the surfactant solution, stir, add a disulfide compound, and carry out reaction to obtain polyurethane microcapsule.
8. The preparation method according to claim 7, characterized in that, In the step of preparing the polyurethane prepolymer, the oligomer polyol is heated to 100-130℃, dehydrated under a vacuum degree ≥0.08 MPa for 2-3 h, cooled down to below 60℃, polyisocyanate is added, and polymerization reaction is carried out at 70-95℃ for 2-5 h to obtain the polyurethane prepolymer; In the step of preparing the polyurethane microcapsule, the surfactant and water are mixed and stirred for 0.5-3 h to obtain a surfactant solution, the polyurethane prepolymer and the core material are dissolved in a solvent to obtain a mixed solution, the mixed solution and the surfactant solution are mixed and stirred for 0.5-2 h, a disulfide compound is added, and reaction is carried out for 10-24 h to obtain the polyurethane microcapsule.
9. Application of the self-repairing polyurethane microcapsule in any one of claims 1-6 in phase change energy storage materials, self-repairing materials, and photosensitive materials.
Citation Information
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