Photo-induced deformation TPU material, and preparation method and application thereof
By bonding modified black phosphorus nanosheets to TPU substrate, the problems of slow response speed, small deformation and poor cycle stability of photodeformable TPU materials are solved, and a photodeformable TPU material with excellent performance is prepared, which is suitable for artificial muscle materials.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHANDONG INOV POLYURETHANE
- Filing Date
- 2026-03-04
- Publication Date
- 2026-06-05
AI Technical Summary
Existing photodeformable TPU materials suffer from slow response speed, small deformation, poor cycle stability, and unsatisfactory mechanical properties. In particular, black phosphorus nanosheets are difficult to disperse uniformly in TPU substrates, affecting the overall performance of the materials.
Modified black phosphorus nanosheets were used as photoresponsive fillers. They were prepared by amino functionalization and reaction with diphenylmethane diisocyanate. The modified black phosphorus nanosheets were then introduced into a TPU substrate in a bonded form to form a photodeformable TPU material.
The photodeformable TPU material exhibits ultrafast response speed, large deformation, excellent mechanical properties, and good cycle stability, making it suitable for the preparation of artificial muscle materials.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of thermoplastic polyurethane elastomer technology, specifically relating to photodeformable TPU materials, their preparation methods, and applications. Background Technology
[0002] Currently, traditional robots mostly use rigid materials and complex motor and gear systems to achieve movement, while living organisms in nature (such as octopuses and caterpillars) can perform complex movements through simple deformation of their soft bodies. Inspired by this, researchers are working to develop "artificial muscle" materials that can simulate biological muscles and respond to external stimuli. Among various driving methods, light, as a clean, wireless energy source that can achieve precise spatiotemporal control, is considered an ideal driving method.
[0003] Photodeformable thermoplastic polyurethane (TPU) is a smart polymer material that emerged in this context. This material combines the excellent mechanical and processing properties of thermoplastic polyurethane with the functional characteristics of photothermal conversion materials. Under irradiation with light of specific wavelengths (such as ultraviolet and visible light), it can rapidly convert light energy into heat energy, thereby inducing reversible deformation of the TPU. In short, this is a polyurethane material that can "move in the presence of light," providing a new approach for achieving efficient and controllable soft actuation.
[0004] Currently, photoresponsive fillers used to modify TPU mainly include carbon-based materials (such as graphene and carbon nanotubes), semiconductor nanomaterials (such as titanium dioxide and zinc oxide), and organic photoresponsive molecules (such as azobenzene derivatives and spiropyran derivatives). However, existing photoresponsive fillers all have many shortcomings: carbon-based materials have a narrow light absorption range, mostly concentrated in the near-infrared region, and their photothermal conversion efficiency needs to be improved; semiconductor nanomaterials have a slow photoresponse speed and poor compatibility with TPU substrates; organic photoresponsive molecules generally have poor photostability, are prone to photofatigue, and have poor dispersion in TPU. These defects lead to problems such as slow response speed, small deformation, poor cycle stability, and significant decay of mechanical properties in the prepared photodeformable TPU materials, making it difficult to meet the needs of practical applications.
[0005] Black phosphorus nanosheets (BPNSs) are a novel two-dimensional layered nanomaterial with a unique wrinkled structure and excellent photoelectric properties. Their light absorption range covers the visible to near-infrared region, exhibiting high photothermal conversion efficiency, and also possessing good mechanical properties and biocompatibility. Introducing black phosphorus nanosheets as photoresponsive fillers into TPU substrates holds promise for preparing high-performance photodeformable materials. However, the strong van der Waals forces between the layers of black phosphorus nanosheets make them prone to aggregation, hindering uniform dispersion within TPU substrates and severely impacting the overall performance of the composite material. Therefore, how to modify black phosphorus nanosheets to improve their performance stability and simultaneously incorporate them into TPU substrates in a bonded manner to prepare TPU composite materials with excellent photodeformable properties, mechanical properties, and cycle stability has become a pressing technical challenge in this field. Summary of the Invention
[0006] To address the shortcomings of existing technologies, the present invention aims to provide a photodeformable TPU material using modified black phosphorus nanosheets as a photoresponsive filler. The resulting photodeformable TPU material possesses both excellent photodeformation properties and good mechanical properties and cycle stability.
[0007] Another objective of this invention is to provide a method for preparing and applying photodeformable TPU materials.
[0008] The technical solution adopted in this invention is as follows:
[0009] The photodeformable TPU material comprises the following raw materials in parts by weight:
[0010] Diisocyanate: 30-38 parts;
[0011] Modified black phosphorus nanosheets: 5-10 parts;
[0012] Polycarbonate diol: 40-50 parts;
[0013] Chain extender: 9-12 parts;
[0014] Catalyst: 0.5-1 part;
[0015] The method for preparing the modified black phosphorus nanosheets includes the following steps:
[0016] Black phosphorus crystals and amino compounds were subjected to ice-water bath ultrasonic treatment in a polar aprotic solvent to obtain amino-functionalized black phosphorus nanosheets; the amino-functionalized black phosphorus nanosheets were dispersed in an aromatic solvent and reacted with diphenylmethane diisocyanate to obtain modified black phosphorus nanosheets.
[0017] The diisocyanate is diphenylmethane diisocyanate or isophorone diisocyanate.
[0018] The method for preparing the modified black phosphorus nanosheets includes the following steps:
[0019] Black phosphorus crystals and dodecylamine were added to anhydrous and oxygen-free N-methylpyrrolidone for ice-water bath sonication. The amino-functionalized black phosphorus nanosheets obtained by centrifugation were washed with anhydrous N-methylpyrrolidone and centrifuged. The purified amino-functionalized black phosphorus nanosheets were dispersed in anhydrous toluene to obtain a dispersion. Diphenylmethane diisocyanate was diluted with anhydrous toluene and added dropwise to the dispersion under argon protection and magnetic stirring at room temperature. After the addition was completed, the temperature was raised to reflux reaction. After the reaction was completed, the mixture was cooled to room temperature, and anhydrous methanol was added to quench the excess diphenylmethane diisocyanate. The mixture was washed repeatedly by centrifugation with a toluene / methanol mixed solvent until the supernatant was clear. The precipitate was dried to obtain modified black phosphorus nanosheets.
[0020] The mass ratio of black phosphorus crystals to dodecylamine is 1:(5-20); the ultrasonic treatment power is 200-400W, and the treatment time is 4-8h; the mass ratio of amino-functionalized black phosphorus nanosheets to diphenylmethane diisocyanate is 1:(2.1-2.3); the reflux reaction temperature is 60-80°C, and the reflux reaction time is 12-24h.
[0021] Preferably, the method for preparing the modified black phosphorus nanosheets includes the following steps:
[0022] Blocky black phosphorus crystals and dodecylamine were added to anhydrous and oxygen-free N-methylpyrrolidone and ultrasonically treated in an ice-water bath at 200-400W power for 4-8 hours. The mass ratio of black phosphorus crystals to dodecylamine was 1:(5-20), and the mass ratio of black phosphorus crystals to anhydrous N-methylpyrrolidone was 1:(20-30). The ultrasonically treated solution was transferred to a centrifuge tube and centrifuged at 3000-4000 r / min to remove the unpeeled thick layer of black phosphorus. The supernatant was then collected and centrifuged at 8000-10000 r / min to collect the amino-functionalized black phosphorus nanosheets. The nanosheets were washed with anhydrous N-methylpyrrolidone and centrifuged to obtain purified amino-functionalized black phosphorus nanosheets. The purified amino-functionalized black phosphorus nanosheets were dispersed in anhydrous toluene to obtain a dispersion. The dispersion was transferred to a three-necked flask using a syringe, wherein the mass ratio of amino-functionalized black phosphorus nanosheets to anhydrous toluene was 1:(50-100). Diphenylmethane diisocyanate was diluted with anhydrous toluene and then transferred to a constant-pressure dropping funnel. Under argon protection and with magnetic stirring at room temperature (300-500 r / min), the diphenylmethane diisocyanate / toluene solution was slowly added dropwise to the dispersion, wherein the mass ratio of amino-functionalized black phosphorus nanosheets to diphenylmethane diisocyanate was 1:(2.1-2.3). After the addition was complete, the reaction system was heated to 60-80°C and refluxed for 12-24 h while maintaining stirring. After the reaction was completed and cooled to room temperature, 2-4 mL of anhydrous methanol was added to the reaction system using a syringe to quench the excess diphenylmethane diisocyanate. The resulting mixture was transferred to a centrifuge tube and washed repeatedly by centrifugation with a toluene / methanol mixed solvent at a volume ratio of 1:(1-3) until the supernatant was clear to remove unreacted diphenylmethane diisocyanate, byproducts and other impurities. The precipitate was dried overnight at 40°C in a vacuum drying oven to obtain modified black phosphorus nanosheets. The product was stored in an argon-filled glove box to avoid light exposure.
[0023] The polycarbonate diol has a number average molecular weight of 1500-2000.
[0024] The chain extender is 1,4-butanediol or 1,3-propanediol.
[0025] The catalyst is bismuth isooctanoate or stannous octanoate.
[0026] The method for preparing the photodeformable TPU material includes the following steps:
[0027] (1) Dehydrate polycarbonate diol to a moisture content of <0.03wt.%, and add diisocyanate to the dehydrated polycarbonate diol under an inert or nitrogen atmosphere to react and obtain a prepolymer with a -NCO content of 10-13wt.%;
[0028] (2) The modified black phosphorus nanosheets, chain extender and catalyst are quickly added to the prepolymer, stirred and mixed and then poured into a mold coated with release agent for curing. After curing, the photodeformed TPU material is obtained.
[0029] In step (1), the reaction temperature is 70-90℃ and the reaction time is 1-3h; in step (2), the stirring speed is 2000-3000r / min, the stirring time is 10-40s, the aging temperature is 100-120℃, and the aging time is 12-48h.
[0030] The aforementioned photodeformable TPU material is used to prepare artificial muscle materials.
[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0032] (1) The photodeformable TPU material prepared by the present invention uses isocyanate-modified black phosphorus nanosheets as photoresponsive fillers. The modified black phosphorus nanosheets can be uniformly dispersed in the TPU substrate in a bonded form, which not only retains the excellent characteristics of black phosphorus nanosheets such as wide-spectrum light absorption and high photothermal conversion efficiency, but also achieves strong interfacial bonding between the filler and the substrate, so that the material has both ultra-fast photoresponse speed, large deformation photodeformation performance, and excellent mechanical properties, while the bending angle decay is not obvious during the cycle of use;
[0033] (2) This invention effectively overcomes the technical defects of existing photodeformable TPU materials, such as slow photoresponse speed, small deformation, poor cycle stability and poor mechanical properties. The photodeformable TPU material prepared has excellent comprehensive performance and can be applied to the preparation of artificial muscle materials. It provides high-performance material support for the research and development of artificial muscles in the fields of soft robots and intelligent drive devices, and expands the practical application scenarios of photodeformable polymer materials. Detailed Implementation
[0034] The present invention will be further described below with reference to the embodiments, but these embodiments do not limit the implementation of the present invention.
[0035] Unless otherwise specified, the raw materials used in the examples and comparative examples are all commercially available materials, and the process methods used in the examples and comparative examples are all conventional methods in the art.
[0036] The following is a description of some of the raw materials used in the examples and comparative examples:
[0037] The preparation method of the modified black phosphorus nanosheets comprises the following steps:
[0038] Blocky black phosphorus crystals and dodecylamine were added to anhydrous and oxygen-free N-methylpyrrolidone and ultrasonically treated for 4 hours at 400W in an ice-water bath. The mass ratio of black phosphorus crystals to dodecylamine was 1:15, and the mass ratio of black phosphorus crystals to anhydrous N-methylpyrrolidone was 1:25. The ultrasonically treated solution was transferred to a centrifuge tube and centrifuged at 3000 rpm to remove the unpeeled thick layer of black phosphorus. The supernatant was collected, and the amino-functionalized black phosphorus nanosheets were collected by centrifugation at 10000 rpm. The nanosheets were washed with anhydrous N-methylpyrrolidone and centrifuged to obtain purified amino-functionalized black phosphorus nanosheets. The purified amino-functionalized black phosphorus nanosheets were dispersed in anhydrous toluene to obtain a dispersion, which was transferred to a three-necked flask using a syringe. The mass ratio of amino-functionalized black phosphorus nanosheets to anhydrous toluene was 1:80. Diphenylmethane diisocyanate was diluted with anhydrous toluene and then transferred to a constant-pressure dropping funnel. Under argon protection and with magnetic stirring at room temperature (500 rpm), the diphenylmethane diisocyanate / toluene solution was slowly added dropwise to the dispersion, wherein the mass ratio of amino-functionalized black phosphorus nanosheets to diphenylmethane diisocyanate was 1:2.2. After the addition was complete, the reaction system was heated to 70°C and refluxed for 18 hours with stirring. After the reaction was completed, it was cooled to room temperature, and 3 mL of anhydrous methanol was added to the reaction system through a syringe to quench excess diphenylmethane diisocyanate. The resulting mixture was transferred to a centrifuge tube and washed repeatedly with a toluene / methanol mixed solvent (volume ratio 1:2) until the supernatant was clear to remove unreacted diphenylmethane diisocyanate, byproducts, and other impurities. The precipitate was dried overnight at 40°C in a vacuum drying oven to obtain modified black phosphorus nanosheets. The product was stored in an argon-filled glove box to avoid light exposure.
[0039] Example 1
[0040] The photodeformable TPU material comprises the following raw materials in parts by weight:
[0041] Diphenylmethane diisocyanate: 35 parts;
[0042] Modified black phosphorus nanosheets: 6 parts;
[0043] Polycarbonate diol: 50 parts;
[0044] 1,4-Butanediol: 9 parts;
[0045] Stannous caprylate: 1 part;
[0046] The polycarbonate diol has a number average molecular weight of 1500.
[0047] The method for preparing the photodeformable TPU material includes the following steps:
[0048] (1) Dehydrate polycarbonate diol to a moisture content of <0.03wt.%, add diphenylmethane diisocyanate to the dehydrated polycarbonate diol under a nitrogen atmosphere, and heat to 70℃ for 2h to obtain a prepolymer with a -NCO content of 10wt.%;
[0049] (2) Modified black phosphorus nanosheets, 1,4-butanediol and stannous octoate were quickly added to the prepolymer. After stirring and mixing at 2500 r / min for 10 s, the mixture was poured into a mold coated with a release agent for curing. The curing temperature was 100℃ and the curing time was 12 h. After curing, the photodeformed TPU material was obtained.
[0050] Example 2
[0051] The photodeformable TPU material comprises the following raw materials in parts by weight:
[0052] Isophorone diisocyanate: 33 parts;
[0053] Modified black phosphorus nanosheets: 10 parts;
[0054] Polycarbonate diol: 40 parts;
[0055] 1,4-Butanediol: 11 parts;
[0056] Bismuth isooctanoate: 1 part;
[0057] The polycarbonate diol has a number average molecular weight of 2000.
[0058] The method for preparing the photodeformable TPU material includes the following steps:
[0059] (1) Dehydrate polycarbonate diol to a moisture content of <0.03wt.%, add isophorone diisocyanate to the dehydrated polycarbonate diol under a nitrogen atmosphere, and heat to 90℃ for 3h to obtain a prepolymer with a -NCO content of 13wt.%;
[0060] (2) Modified black phosphorus nanosheets, 1,4-butanediol and bismuth isooctanoate were quickly added to the prepolymer. After stirring and mixing at 2500 r / min for 10 s, the mixture was poured into a mold coated with a release agent for curing. The curing temperature was 100℃ and the curing time was 48 h. After curing, the photodeformed TPU material was obtained.
[0061] Example 3
[0062] The photodeformable TPU material comprises the following raw materials in parts by weight:
[0063] Isophorone diisocyanate: 35 parts;
[0064] Modified black phosphorus nanosheets: 10 parts;
[0065] Polycarbonate diol: 45 parts;
[0066] 1,3-Propanediol: 9 parts;
[0067] Stannous octoate: 0.5 parts;
[0068] The polycarbonate diol has a number average molecular weight of 1500.
[0069] The method for preparing the photodeformable TPU material includes the following steps:
[0070] (1) Dehydrate polycarbonate diol to a moisture content of <0.03wt.%, add isophorone diisocyanate to the dehydrated polycarbonate diol under a nitrogen atmosphere, and heat to 80℃ for 2h to obtain a prepolymer with a -NCO content of 12wt.%;
[0071] (2) Modified black phosphorus nanosheets, 1,3-propanediol and stannous octoate were quickly added to the prepolymer. After stirring and mixing at 2500 r / min for 10 s, the mixture was poured into a mold coated with a release agent for curing. The curing temperature was 120℃ and the curing time was 48 h. After curing, the photodeformable TPU material was obtained.
[0072] Comparative Example 1
[0073] The difference from Example 1 is that modified black phosphorus nanosheets are not added to the formulation components, while the other conditions are the same as in Example 1.
[0074] Comparative Example 2
[0075] The difference from Example 1 is that the modified black phosphorus nanosheets in the formulation are replaced with an equal weight of black phosphorus powder (particle size 5±0.5μm), and the other conditions are the same as in Example 1.
[0076] Comparative Example 3
[0077] The difference from Example 1 is that the modified black phosphorus nanosheets in the formulation are replaced with an equal weight of carbon black (particle size of 5±0.5μm), and the other conditions are the same as in Example 1.
[0078] The TPU materials prepared in the examples and comparative examples were respectively converted into test samples by injection molding, and the performance of the test samples was tested. The injection molding process is as follows:
[0079] The obtained TPU material was crushed and granulated, and then added to an injection molding machine to prepare test samples. The temperatures of each section of the injection molding machine were set to 210℃, 205℃, 205℃, and 200℃.
[0080] The testing method is as follows:
[0081] Hardness: Tested according to AST D2240;
[0082] Tensile strength: Tested according to ASTM D412;
[0083] Tear strength: Tested according to ASTM D412;
[0084] Migration resistance: The test sample was placed at 85% humidity and 85℃ for 7 days, and the precipitation of the sample was observed.
[0085] Maximum bending angle: A strip sample (50mm long × 5mm wide × 0.5mm thick) was fixed at one end, and irradiated at a wavelength of 808nm and an intensity of 1.0W / cm². 2 Under vertical irradiation by a near-infrared laser, the bending angle of the free end of the sample when it reaches bending equilibrium (the bending angle no longer increases with irradiation time) is recorded.
[0086] Bending angle attenuation rate (1000 cycles): A strip sample (50mm long × 5mm wide × 0.5mm thick) was fixed at one end. A fixed irradiation cycle was set (60s on, 60s off). The bending angle θ1 at the end of the first irradiation cycle was recorded. This cycle was repeated 1000 times. The bending angle θ1 at the end of the 1000th irradiation cycle was recorded. 1000 The bending angle attenuation rate (wavelength 808nm, irradiance 1.0W / cm²) is calculated using the following formula. 2 (Vertical illumination by near-infrared laser)
[0087] .
[0088] Full response time: After fixing one end of the strip sample (50mm long × 5mm wide × 0.5mm thick), turn off the light source and simultaneously turn on the light source (wavelength 808nm, irradiance 1.0W / cm²). 2 A near-infrared laser (vertically irradiated) and a timer were used to monitor the bending angle of the sample in real time, recording the angle up to 0.9 × θ. max The time required for θ to complete the response is the total response time, where θ max This represents the maximum bending angle.
[0089] The test results are shown in Table 1-2.
[0090] Table 1. Test results of mechanical properties and migration resistance
[0091]
[0092] Table 2. Test results of maximum bending angle, bending angle attenuation rate, and total response time.
[0093]
[0094] As shown in Tables 1-2, a comparison of the test data of Example 1 and the comparative example shows that the present invention achieves controllable adjustment of the photo-bending angle of the material in the range of 0-50° by introducing modified black phosphorus nanosheets into the system. At the same time, the data analysis of Example 1 and Comparative Example 2 shows that introducing black phosphorus nanosheets into the TPU system by means of modified bonding optimizes the interfacial reaction characteristics, so that the prepared TPU material has both excellent mechanical properties and photo-deformation properties, and there is no obvious precipitation after being placed at 85% humidity and 85°C for 7 days, showing excellent migration resistance. A comparison of Example 1 and Comparative Example 3 shows that the modified black phosphorus nanosheets have a higher photothermal conversion efficiency than conventional carbon black photothermal conversion agents, and can endow the material with better photo-deformation properties.
Claims
1. A photodeformable TPU material, characterized in that, The ingredients include the following parts by weight: Diisocyanate: 30-38 parts; Modified black phosphorus nanosheets: 5-10 parts; Polycarbonate diol: 40-50 parts; Chain extender: 9-12 parts; Catalyst: 0.5-1 part; The method for preparing the modified black phosphorus nanosheets includes the following steps: Black phosphorus crystals and dodecylamine were added to anhydrous and oxygen-free N-methylpyrrolidone and subjected to ice-water bath sonication. The amino-functionalized black phosphorus nanosheets obtained by centrifugation were washed with anhydrous N-methylpyrrolidone and centrifuged. The purified amino-functionalized black phosphorus nanosheets were dispersed in anhydrous toluene to obtain a dispersion. Diphenylmethane diisocyanate was diluted with anhydrous toluene and added dropwise to the dispersion under argon protection and magnetic stirring at room temperature. After the addition was completed, the temperature was raised to reflux reaction. After the reaction was completed, the mixture was cooled to room temperature, and anhydrous methanol was added to quench the excess diphenylmethane diisocyanate. The mixture was washed repeatedly by centrifugation with a toluene / methanol mixed solvent until the supernatant was clear. The precipitate was dried to obtain modified black phosphorus nanosheets. The method for preparing the photodeformable TPU material is characterized by comprising the following steps: (1) Diisocyanate was added to dehydrated polycarbonate diol for reaction to obtain a prepolymer with -NCO content of 10-13 wt.%; (2) Add modified black phosphorus nanosheets, chain extender and catalyst to the prepolymer, stir and mix, pour into a mold for curing, and obtain photodeformed TPU material after curing.
2. The photodeformable TPU material according to claim 1, characterized in that, The diisocyanate is diphenylmethane diisocyanate or isophorone diisocyanate.
3. The photodeformable TPU material according to claim 1, characterized in that, The mass ratio of black phosphorus crystals to dodecylamine is 1:(5-20); the ultrasonic treatment power is 200-400W, and the treatment time is 4-8h; the mass ratio of amino-functionalized black phosphorus nanosheets to diphenylmethane diisocyanate is 1:(2.1-2.3); the reflux reaction temperature is 60-80°C, and the reflux reaction time is 12-24h.
4. The photodeformable TPU material according to claim 1, characterized in that, The polycarbonate diol has a number average molecular weight of 1500-2000.
5. The photodeformable TPU material according to claim 1, characterized in that, The chain extender is 1,4-butanediol or 1,3-propanediol.
6. The photodeformable TPU material according to claim 1, characterized in that, The catalyst is bismuth isooctanoate or stannous octanoate.
7. The photodeformable TPU material according to claim 1, characterized in that, In step (1), the reaction temperature is 70-90℃ and the reaction time is 1-3h; in step (2), the stirring speed is 2000-3000r / min, the stirring time is 10-40s, the aging temperature is 100-120℃, and the aging time is 12-48h.
8. An application of the photodeformable TPU material according to any one of claims 1-7, characterized in that, Used to prepare artificial muscle materials.