Temperature-sensitive color-changing degradable material and bionic artware thereof

Abstract

The invention discloses a temperature-sensitive color-changing degradable material and bionic artware thereof, and belongs to the technical field of materials. The invention provides a temperature-sensitive color-changing degradable material. The temperature-sensitive color-changing degradable material comprises the following components: 100 parts of a degradable organic polymer, 10-50 parts of a double-layer silicon dioxide microcapsule and 0.001-2 parts of an initiator. The double-layer silicon dioxide microcapsule can be subjected to phase change at a relatively low temperature lower than 100 DEG C so as to change color; the phase change temperature is low, so that the color change effect of the manufactured bionic handicraft in the normal-temperature display or playing process is facilitated, and the ornamental value of the handicraft is improved; and the silicon dioxide microcapsule has the characteristics of high strength, high temperature resistance, acid and alkali resistance, strong sealing property, temperature-sensitive discoloration, cross-linking agent and the like, can effectively protect the internal phase-change material and the colored material for a long time, and can change color repeatedly without influencing the discoloration effect.

Description

Technical Field

[0001] This invention relates to the field of biomimetic materials technology, specifically to a thermosensitive color-changing biodegradable material and its biomimetic handicrafts. Background Technology

[0002] With increasing environmental awareness, biodegradable materials are being used more and more widely in various fields. However, traditional biodegradable materials have limited functionality and cannot meet the demands of high-end handicrafts for dynamic visual effects. Thermochromic materials, capable of changing color with temperature, have been applied in various fields. However, most existing thermochromic materials use non-degradable polymers as a matrix, generating large amounts of plastic waste and causing serious environmental problems. Furthermore, introducing thermochromic agents into biodegradable matrices often presents challenges such as poor compatibility, insufficient color stability, and difficulty in controlling the response rate, limiting their application in fields like biomimetic crafts. The color-changing mechanisms of inorganic thermochromic materials exhibit diverse characteristics, with some mechanisms possessing high complexity. Crystal transformation is one of the key pathways: when a crystalline substance is heated to a specific temperature threshold, its crystal structure transforms from one crystalline phase to another. This phase change directly alters the material's absorption and reflection characteristics of visible light, thus resulting in color differences.

[0003] Liquid crystal thermochromic materials exhibit significant advantages in temperature response sensitivity, with color-changing performance superior to various temperature-indicating materials. However, two major limitations exist in practical applications: firstly, liquid crystal materials require microencapsulation technology to achieve functional applications; secondly, the current high cost of liquid crystal material preparation restricts its large-scale promotion. The color development of this type of material is essentially a physical process, stemming from the color changes caused by differences in the reflection, refraction, and absorption characteristics of incident light due to different crystal structures.

[0004] The color-changing mechanism of organic thermochromic materials is mainly based on molecular structure reconstruction triggered by changes in the pH of the medium. These reversible thermochromic materials exhibit rich diversity, with functional pigment systems encompassing multiple compound families, including spirocyclic, bisanthrone, Schiff bases, fluoresceins, and triphenylmethanes. These organic substances achieve selective absorption or reflection of the visible spectrum through temperature-induced molecular conformational changes, ultimately completing the reversible color change process.

[0005] Existing technology CN114618404A discloses a temperature-controlled color-changing microcapsule, comprising a core and a shell layer encapsulating the core. The core includes a color-developing agent, a color-developing agent, and a temperature-sensitive solvent, wherein the temperature-sensitive solvent is dodecyl ester, and the color-changing temperature of the temperature-controlled color-changing microcapsule is 24-28℃; the shell layer is melamine resin. However, melamine ester can soften at 150℃ and is suitable for processing. Temperature-controlled color-changing microcapsules prepared using melamine as the shell are not convenient to be prepared into other materials by melt extrusion, thus limiting their application.

[0006] Biomimetic crafts strive to realistically mimic the forms and characteristics of natural organisms. However, most current biomimetic crafts can only achieve static form imitation, failing to reflect the dynamic changes of organisms in different environments and lacking interactivity and fun. Therefore, developing a material with both good biodegradability and stable temperature-sensitive color-changing properties, and applying it to biomimetic crafts, has significant practical implications. Summary of the Invention

[0007] In order to overcome the shortcomings of the existing technology, the purpose of this invention is to provide a thermosensitive color-changing biodegradable material and its biomimetic handicrafts. The packaging material has technical effects such as being degradable, colorfast, recolorable, and thermosensitive at low temperatures.

[0008] In a first aspect, the present invention provides a thermosensitive color-changing biodegradable material, comprising the following components by weight: 100 parts of biodegradable organic polymer, 10-50 parts of bilayer silica microcapsules, and 0.001-2 parts of initiator.

[0009] The preparation method of the bilayer silica microcapsules is as follows: S1: Add colored materials and surfactants to water, stir, heat, and homogenize to prepare emulsion solution 1.

[0010] S2: Add siloxane to the above emulsion solution 1, stir, add ammonia water, stir to react, filter and dry to obtain monolayer silica microcapsules.

[0011] S3: Add monolayer silica microcapsules to the phase change material, heat and stir until uniform, then add the mixture to water, heat and stir to prepare emulsion solution 2; S4: Add siloxane to the above emulsion solution 2, stir, add ammonia water, stir to react; add aminosiloxane, stir to react, filter and dry to obtain amino-modified silica microcapsules.

[0012] S5: In a PBS solution of 3-maleimide propionic acid, N-hydroxysuccinimide (NHS) and 1-ethyl-(3-dimethylaminopropyl)carbodiimide (EDC) were added and stirred to react. Subsequently, amino-modified silica microcapsules were added, stirred to react, filtered and dried to obtain bilayer silica microcapsules.

[0013] Preferably, the biodegradable organic polymer is prepared by polymerization of polylactic acid and polyethylene glycol. The polylactic acid has a molecular weight range of 5000 Da to 100000 Da; the polyethylene glycol is selected from polyethylene glycols with terminal hydroxyl, amino, or carboxyl groups. The molecular weight of the polyethylene glycol ranges from 400 Da to 10000 Da. The mass ratio of polylactic acid to polyethylene glycol is 1:(0.001-10).

[0014] Preferably, the initiator is selected from at least one of benzoyl peroxide (BPO), dicumyl peroxide (DCP), and di-tert-butyl peroxide (DTBP).

[0015] Preferably, the aminosiloxane is selected from at least one of γ-aminopropyltrimethoxysilane (APTMS), γ-aminopropyltriethoxysilane (APTES), and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (AEAPTES).

[0016] Preferably, the siloxane is selected from at least one of methyl orthosilicate and ethyl orthosilicate.

[0017] Preferably, the colored material is selected from at least one of organic dyes or inorganic dyes. The organic dyes include one or more of anthracene dyes, azo dyes, indigo dyes, arylmethane dyes, sulfur dyes, phthalocyanine dyes, cyanine dyes, and hybrid dyes; the inorganic dyes are one or more of ultramarine violet, iron oxide red, molybdenum bismuth yellow, ultramarine blue, ultramarine red, and bismuth vanadate.

[0018] The phase change material is selected from at least one of the following: decanoic acid, lauric acid, stearic acid, paraffin, stearate, phenyl salicylate, palmitic acid, n-octadecane, and n-nonadecane.

[0019] Secondly, the present invention provides a biomimetic handicraft, which is prepared from the aforementioned thermosensitive color-changing biodegradable material.

[0020] Furthermore, the thermosensitive color-changing biodegradable material is obtained by mixing biodegradable organic polymer, double-layer silica microcapsules, and initiator in a premixer according to the weight ratio, followed by melt extrusion, granulation, and drying in a twin-screw extruder.

[0021] Preferably, the biomimetic handicraft is selected from at least one of plastic plants, plastic animals, and dolls.

[0022] Compared with the prior art, the present invention has the following technical effects: The purpose of this invention is to provide a thermosensitive color-changing biodegradable material and its biomimetic handicrafts. The packaging material has technical effects such as being biodegradable, colorfast, recolorable, and color-changing at low temperatures.

[0023] This invention prepares thermosensitive color-changing bilayer silica microcapsules by encapsulating colored materials within a bilayer of silica. The microcapsules contain a phase change material that undergoes a phase change at a relatively low temperature below 100°C. The phase change material is opaque in its solid state and transparent in its liquid state, thus revealing the color of the colored material encapsulated within the microcapsule, resulting in color change. The low phase change temperature facilitates the color-changing effect of the biomimetic crafts during room temperature display or handling, enhancing their aesthetic appeal. Furthermore, the silica microcapsules possess high strength, high temperature resistance, acid and alkali resistance, and strong sealing properties, effectively protecting the internal phase change and colored materials for a long period, allowing for repeated color changes without affecting the effect. Additionally, the bilayer silica microcapsules are modified with 3-maleimide propionic acid via amino groups, enabling chemical coupling to a biodegradable copolymer. Therefore, the bilayer silica microcapsules are not easily detached, maintaining the stability of the long-term color-changing effect on the material surface. The 3-maleimide propionic acid modified on the surface of the silica microcapsules can be chemically coupled and fixed to the polymer matrix to prevent detachment; its high strength and temperature resistance (>200℃) make it suitable for twin-screw melt extrusion processes, which is beneficial for industrial production. The crosslinking agent effect of the silica microcapsules described in this invention can improve the performance of the prepared thermosensitive color-changing biodegradable material. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the molecular structure of the thermosensitive color-changing biodegradable material in Example 1 (the sphere represents the double-layered silica microcapsule 1). Detailed Implementation

[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. The described embodiments are only some preferred embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Unless otherwise specified, the experimental methods used in the embodiments are conventional or common methods in the art, and the materials and reagents used are commercially available unless otherwise specified.

[0027] The raw materials used in the examples and comparative examples are described below: Polylactic acid: Tianjin Xins (80kDa, end carboxyl group content 12.6%) μ mol / g); Amino-polyethylene glycol (H2N-PEG-NH2): purchased from Nanjing Shizhou Biotechnology Co., Ltd. (5kDa); Dicumyl peroxide (DCP): purchased from Wuhan Lvjing Fenghua Biotechnology Co., Ltd. Permanent Orange RN: Purchased from Henan Weitixi Chemical Technology Co., Ltd.; Jin Guanghong: Purchased from Wuhan Camick Technology Co., Ltd.

[0028] Sodium dodecyl sulfate: purchased from Shanghai Jizhi Biochemical Technology Co., Ltd.; N-hydroxysuccinimide (NHS): Purchased from Shanghai Jizhi Biochemical Technology Co., Ltd.; 1-Ethyl-(3-dimethylaminopropyl)carbodiimide (EDC): purchased from Shanghai Jizhi Biochemical Technology Co., Ltd.; Stearic acid: purchased from Shanghai Jizhi Biochemical Technology Co., Ltd.

[0029] Decanoic acid (melting point 31.5℃): purchased from Shanghai Runjie Technology Development Co., Ltd.

[0030] Paraffin wax (high purity, melting point approximately 51°C): Sangon Biotech (Shanghai) Co., Ltd. Phenyl salicylate (melting point 41-42℃): purchased from Wuhan Fuxin Chemical Co., Ltd. γ-aminopropyltrimethoxysilane (APTMS): purchased from Shanghai Zhuorui Chemical Co., Ltd.; Tetraethyl orthosilicate (TEOS): Purchased from Shanghai Zhuorui Chemical Co., Ltd.

[0031] Unless otherwise specified, all components and raw materials used in the embodiments and comparative examples of this invention are commercially available, and the same type of components and raw materials are used in each parallel experiment.

[0032] Preparation of polylactic acid-polyethylene glycol polymer (self-made): Polylactic acid (PLA) was dissolved in dichloromethane, and 1.2 eq. (equivalents) of DCC and 1.2 eq. (equivalents) of NHS were added. The mixture was stirred at 100 rpm for 2 hours at room temperature, followed by the addition of amino-polyethylene glycol (PEG), and the reaction was continued at room temperature for another 6 hours. The reaction solution was then added to cold diethyl ether to precipitate the polymer, which was then filtered and dried to obtain the PLA-PEG polymer. The mass ratio of PLA to amino-PEG was 4:1.

[0033] Preparation of bilayer silica microcapsules (self-made): S1: Add organic dye and sodium dodecyl sulfate (surfactant) to water (20 parts), stir magnetically at 600 rpm, heat at 50°C for 5 min, and homogenize three times in a high-pressure homogenizer (PHA-060I) at 600 bar to prepare emulsion solution 1.

[0034] S2: Add TEOS to the above emulsion solution 1, stir magnetically at 600 rpm, add 1 mol / L ammonia to adjust the pH to 10, stir for 0.5 h, filter and dry to obtain monolayer silica microcapsules.

[0035] S3: Add single-layer silica microcapsules to the phase change material, heat at 60°C and stir at 600 rpm for 5 minutes until homogenized, then add the mixture to water (30 parts), heat at 60°C and stir at 2000 rpm for 5 minutes to prepare emulsion solution 2. S4: Add TEOS to the above emulsion solution 2, stir for 5 min, add 1 mol / L ammonia to adjust the pH to 10, stir at 600 rpm for 0.5 h; add γ-aminopropyltrimethoxysilane, stir for 0.5 h, filter and dry to obtain amino-modified silica microcapsules.

[0036] S5: In a PBS (pH 5.5) solution of 3-maleimide propionic acid, N-hydroxysuccinimide (NHS) and 1-ethyl-(3-dimethylaminopropyl)carbodiimide (EDC) were added and stirred at 100 rpm for 1 h. Subsequently, amino-modified silica microcapsules were added and stirred for 2 h. The mixture was then filtered and dried to obtain bilayer silica microcapsules.

[0037] Table 1. Amounts of raw materials used in the preparation of each group of double-layer silica microcapsules (parts by weight)

[0038] Example 1

[0039] A thermosensitive, color-changing, biodegradable material is prepared as follows: Polylactic acid-polyethylene glycol polymer and double-layer silica microcapsules were added to a high-speed mixer. The temperature was preset to 160℃ and the speed was set to 700 r / min for 10 min. Then, dicumyl peroxide initiator was added and the mixture was stirred for 5 min at 1500 r / min to obtain a mixture. The feed speed was set to 35 r / min, and the mixture was injected into a twin-screw extruder. The extruder barrel temperatures were set at 190, 200, 200, 200, 200, 200, 200, and 190℃ (die head temperature). The main extruder speed was 300 r / min, and the vacuum level was set to ≤0.1 MPa. The mixture was extruded, granulated, and dried for later use to obtain a thermosensitive, color-changing, biodegradable material.

[0040] Examples 2-4 Examples 2-4 follow the same preparation steps as Example 1, the only difference being the adjustment of the raw materials or the amount of raw materials used (see Table 2 for details).

[0041] Comparative Examples 1-2 Comparative Examples 1-2 follow the same preparation steps as Example 1, except that the raw materials or the amount of raw materials used were adjusted (see Table 2 for details).

[0042] Table 2. Ingredients (parts by weight) for the raw materials used in Examples 1-4 and Comparative Examples 1-2

[0043] (1) Determination of color change temperature range The materials prepared in Examples 1-4 and Comparative Examples 1-2 were placed in a constant temperature water bath, and the temperature at which the color changed was recorded. The temperature of the constant temperature water bath was set to an initial temperature of 25 degrees Celsius with a gradient of 0.5 degrees Celsius, and was adjusted every 5 minutes. The temperature at which the material changed color was recorded, and the color was observed after the color change (visual observation).

[0044] Table 3 Color Change Temperature Record Table

[0045] According to the above experimental data, the thermosensitive color-changing biodegradable materials in Examples 1-4 can change color in a temperature range of 27.5-55℃. This temperature range is suitable for the daily display and preservation of bionic crafts, which helps to highlight the design aesthetics of bionic crafts and improve their ornamental value.

[0046] (2) Color change stability High-temperature decolorization-recoloration test: The materials (5cm×5cm×0.3cm) prepared in Examples 1-4 and Comparative Examples 1-2 were placed in boiling water and heated for 30 minutes, then placed in a constant temperature (40℃) forced-air drying oven (Yiheng Instruments: BPG-9056ABPG-9106A) for forced-air drying for 1 hour, cooled and decolorized, and this process was repeated 100 times. The color change stability of the materials was evaluated using color difference.

[0047] Color difference measurement: The L, a, and b values ​​of the material were measured using an Escherich colorimeter. The results of 0 and 100 decolorization-recoloring tests were recorded as L0, a0, b0, and L, respectively. 100 a 100 b 100 Color difference calculation: Where: ΔL*=L0-L 100 ; Δa*=a0-a 100 Δb*=b0-b 100 .

[0048] Table 4 Color Change Stability

[0049] According to the data in Table 4, the thermosensitive color-changing biodegradable materials prepared in Examples 1-4 did not change their color-changing temperature after undergoing the high-temperature decolorization-recoloration test. This indicates that Examples 1-4 of the present invention have good high-temperature resistance and good color-changing stability. Furthermore, Examples 1-4 show that the color difference change of the prepared thermosensitive color-changing biodegradable materials after the test is less than 0.18, significantly less than the color difference perceptible to the human eye (ΔE<1). However, the color difference changes in Comparative Examples 1 and 2 are larger and perceptible to the naked eye. The difference between Comparative Example 1 and Example 1 is that no initiator was added; that is, the bilayer silica microcapsules 1 were not crosslinked onto the polylactic acid-polyethylene glycol polymer. Therefore, after undergoing the high-temperature decolorization-recoloration test, the thermosensitive color-changing biodegradable materials prepared in Comparative Example 1 are prone to detachment of the bilayer silica microcapsules 1, resulting in color difference changes. Compared with Example 1, Comparative Example 2 shows that microcapsules 5 were not modified with 3-maleimide propionic acid. Therefore, microcapsules 5 do not have the function of a crosslinking agent and cannot be crosslinked to polylactic acid-polyethylene glycol polymer. They are prone to peeling off after the high-temperature decolorization-recoloring test, resulting in color difference changes.

[0050] (3) Tensile property test The test was conducted in accordance with GB / T1040.1-2018 "Determination of Tensile Properties of Plastics" to determine the elongation at break.

[0051] The Shore A hardness was determined according to GB / T531-2008 "Test Method for Shore A Hardness of Vulcanized Rubber".

[0052] Table 5 Tensile properties and hardness

[0053] According to the data in Table 5, the thermosensitive color-changing biodegradable materials prepared in Examples 1-4 of this application have better tensile properties than polylactic acid and are more suitable for industrial processing. Secondly, compared with Comparative Examples 1-2, Examples 1-4 show that silica microcapsules also act as crosslinking agents, which can improve the tensile strength of thermosensitive color-changing biodegradable materials.

[0054] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A thermosensitive, color-changing, biodegradable material, characterized in that, By weight, it comprises the following components: 100 parts of biodegradable organic polymer, 10-50 parts of bilayer silica microcapsules, and 0.001-2 parts of initiator; The preparation method of the bilayer silica microcapsules is as follows: S1: Add colored materials and surfactants to water, stir, heat, and homogenize to prepare emulsion solution 1; S2: Add siloxane to the above emulsion solution 1, stir, add ammonia water, stir to react, filter and dry to obtain single-layer silica microcapsules; S3: Add monolayer silica microcapsules to the phase change material, heat and stir until uniform, then add the mixture to water, heat and stir to prepare emulsion solution 2; S4: Add siloxane to the above emulsion solution 2, stir, add ammonia water, stir to react; add aminosiloxane, stir to react, filter and dry to obtain amino-modified silica microcapsules; S5: In a PBS solution of 3-maleimide propionic acid, N-hydroxysuccinimide and 1-ethyl-(3-dimethylaminopropyl)carbodiimide were added and stirred to react. Subsequently, amino-modified silica microcapsules were added, stirred to react, filtered and dried to obtain bilayer silica microcapsules.

2. The thermosensitive color-changing biodegradable material according to claim 1, characterized in that, The biodegradable organic polymer is prepared from polylactic acid and polyethylene glycol.

3. The thermosensitive color-changing biodegradable material according to claim 1, characterized in that, The initiator is selected from at least one of benzoyl peroxide (BPO), dicumyl peroxide (DCP), and di-tert-butyl peroxide (DTBP).

4. The thermosensitive color-changing biodegradable material according to claim 1, characterized in that, The siloxane is selected from at least one of methyl orthosilicate and ethyl orthosilicate.

5. The thermosensitive color-changing biodegradable material according to claim 1, characterized in that, The aminosiloxane is selected from at least one of γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane.

6. The thermosensitive color-changing biodegradable material according to claim 1, characterized in that, The colored material is selected from at least one of organic dyes or inorganic dyes.

7. The thermosensitive color-changing biodegradable material according to claim 1, characterized in that, The phase change material is selected from at least one of the following: decanoic acid, lauric acid, stearic acid, paraffin, stearate, phenyl salicylate, palmitic acid, n-octadecane, and n-nonadecane.

8. A biomimetic handicraft, characterized in that, It is prepared from the thermosensitive color-changing biodegradable material according to any one of claims 1-7.

9. The biomimetic craft according to claim 8, characterized in that, The biomimetic crafts are designed based on at least one of plants, animals, or dolls.

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