Processing method of a fiber-based sunshade material with an automatic temperature regulation function

Abstract

The present invention discloses a processing method of a fiber-based sunshade material with an automatic temperature regulation function, belonging to the technical field of functional textile processing. The present invention prepares modified thermosensitive phase change microcapsules with high photothermal conversion efficiency and heat storage capacity, and applies them to a foamed coating to obtain a processing method of a fiber-based sunshade material with the functions of light absorption and heat storage and automatic temperature regulation by releasing heat at low temperature. The specific process steps include: (1) preparation of modified thermosensitive phase change microcapsules; (2) preparation of a fiber-based sunshade material with an automatic temperature regulation function. Compared with the preparation methods of traditional sunshade products, the modified process of the modified thermosensitive phase change microcapsules of the present invention is simple and the conditions are mild. Not only does it have a good automatic temperature regulation function after finishing, but also has a lasting and stable finishing effect.

Description

Technical Field

[0001] The present invention belongs to the technical field of functional textile processing, and particularly relates to a processing method of a fiber-based sunshade material with an automatic temperature regulation function. Background Technique

[0002] Fiber-based light-shielding materials (fiber-based sunshade materials) are widely used in home textiles such as curtains and outdoor products such as sunshades. In addition to household use, they often appear in places such as hotels, cinemas, and large shopping malls. The light-shielding coated fabric is obtained by coating the surface of ordinary fabric; usually, a light-shielding agent such as titanium dioxide, carbon black, or other coatings is added to the coating agent, and multiple coating finishes are carried out to achieve the light-shielding effect. When light irradiates the fabric surface coating, it is reflected or absorbed, so that it cannot penetrate the fabric. At present, the common coating methods of light-shielding fabrics are foam coating and transfer coating, among which foam coating is the most common.

[0003] A thermosensitive phase change material is a substance that can absorb or release heat from the environment depending on its own reversible phase change performance within a certain temperature range; it can absorb heat in a high-temperature environment and complete the phase transition from solid to liquid; conversely, when the indoor environment temperature decreases, it can automatically convert from liquid to solid, producing a heat release effect. On the other hand, a thermosensitive phase change microcapsule is a microcapsule formed by coating a phase change material with an organic or inorganic chemical by using microcapsule technology. Since the phase change process of its core material is a reversible reaction, it can be reused without causing waste of resources. The thermosensitive phase change microcapsule realizes the long-term solidification of the phase change material, solves problems such as its easy leakage, phase separation, corrosion, and environmental pollution, reduces the interference of the external environment on it, improves its durability and stability, and the smaller particle size also improves its heat transfer performance and processing performance, expanding the application range.

[0004] Combining the thermosensitive phase change microcapsule with textiles by a certain method is expected to prepare textiles with heat storage and temperature regulation functions, and even fiber-based sunshade materials. Such fiber products can automatically adjust according to the change of the external environment temperature. For example, when the external environment temperature decreases, the thermosensitive phase change microcapsule will release the previously stored heat to achieve the function of raising the surrounding environment temperature; when the external environment temperature increases, the thermosensitive phase change microcapsule will absorb and store heat to achieve the function of heat storage, thereby playing a role in automatically regulating the microenvironment temperature to a certain extent.

[0005] Photothermal materials are a type of materials that can absorb the energy of light, convert the energy of light into heat and diffuse it into the external environment, and have been widely used in the processing of various composite materials. Currently, the widely studied photothermal materials mainly include noble metal nanomaterials, semiconductor materials, carbon-based materials, and organic materials. Photothermal materials based on the synthesis of melanin nanoparticles have been widely used in photothermal therapy and seawater desalination. Combining photothermal materials with thermosensitive phase change microcapsules is expected to improve the photothermal conversion efficiency and heat storage capacity of thermosensitive phase change microcapsules. Textiles with high photothermal conversion efficiency and heat storage capacity have good application prospects in low-temperature weather and can be used in sunshade textiles (such as curtains), which can store heat during the day under sunlight and release heat when the temperature drops at night, improving the indoor temperature. Summary of the Invention

[0006] Technical Problem:

[0007] To provide a preparation method of modified thermosensitive phase change microcapsules, the prepared modified thermosensitive phase change microcapsules have high photothermal conversion efficiency and heat storage capacity, and can be used to prepare foamed coating sunshade textiles with excellent photothermal performance, heat storage and heat release performance and temperature regulation function.

[0008] Technical Solution:

[0009] On the one hand, a preparation method of modified thermosensitive phase change microcapsules is provided, which comprises the following steps:

[0010] (1) Dissolve levodopa completely in an aqueous solution with a pH value of 8 - 9 to obtain a levodopa solution with a concentration of 0.5 - 2 g / L; stir the self-oxidation polymerization reaction at 20 - 80 °C for 2 - 24 h to obtain a dispersion of poly(levodopa) nanoparticles;

[0011] (2) Add polyethyleneimine with a molecular weight of 600 - 10000 Da and thermosensitive phase change microcapsules with a phase transition temperature range of 5 - 10 °C to the dispersion of poly(levodopa) nanoparticles to obtain a mixed system I, wherein the concentration of poly(levodopa) nanoparticles in the mixed system I is 0.25 - 1 g / L, the concentration of polyethyleneimine is 0.25 - 1 g / L, and the concentration of thermosensitive phase change microcapsules is 5 - 10 g / L; stir the mixed system I at 20 - 80 °C for 2 - 24 h for co-deposition cross-linking reaction to obtain a dispersion of poly(levodopa) nanoparticles / polyethyleneimine modified thermosensitive phase change microcapsules;

[0012] (3) Lyophilize the dispersion of poly(levodopa) nanoparticles / polyethyleneimine modified thermosensitive phase change microcapsules to obtain poly(levodopa) nanoparticles / polyethyleneimine modified thermosensitive phase change microcapsule powder.

[0013] In some embodiments, the concentration of poly-L-dopa nanoparticles in the hybrid system I is 0.25 to 0.5 g / L, the concentration of polyethyleneimine is 0.25 to 0.5 g / L, and the concentration of thermosensitive phase change microcapsules is 5 to 10 g / L; and the mass ratio of poly-L-dopa nanoparticles, polyethyleneimine, and thermosensitive phase change microcapsules is 1:1:20.

[0014] On the other hand, there is provided a modified thermosensitive phase change microcapsule prepared by the foregoing method.

[0015] In yet another aspect, there is provided an application of the foregoing modified thermosensitive phase change microcapsule in the preparation of a coated sunshade textile having a temperature regulation function.

[0016] In yet another aspect, there is provided a method for preparing a foamed coated sunshade textile having a temperature regulation function, which comprises the following steps:

[0017] Step S1: Prepare poly-L-dopa nanoparticle / polyethyleneimine modified thermosensitive phase change microcapsule powder according to the foregoing method;

[0018] Step S2: Disperse the poly-L-dopa nanoparticle / polyethyleneimine modified thermosensitive phase change microcapsule powder in an aqueous solution to obtain a poly-L-dopa nanoparticle / polyethyleneimine modified thermosensitive phase change microcapsule dispersion; add a kerosene thickener, a polyacrylate sizing agent, and a foam stabilizer emulsion to the poly-L-dopa nanoparticle / polyethyleneimine modified thermosensitive phase change microcapsule dispersion, adjust the pH value to 8 to 9 with ammonia water, and mix well to obtain a foamed coating finishing solution, wherein the final concentration of the poly-L-dopa nanoparticle / polyethyleneimine modified thermosensitive phase change microcapsule powder in the foamed coating finishing solution is 1 to 2 g / L, the final concentration of the polyacrylate is 20 to 30 g / L, the final concentration of the foam stabilizer is 5 to 6 g / L, and the volume fraction of the kerosene thickener is 2 to 3%;

[0019] Step S3: Foam the foamed coating finishing solution, then coat it on the surface of the fabric, and bake it to obtain a foamed coated sunshade textile having a temperature regulation function.

[0020] In some embodiments, the foam stabilizer in Step S2 is ammonium stearate.

[0021] In some embodiments, the foaming ratio of the foamed coating finishing solution in Step S3 is 1:3 to 1:4.

[0022] In some embodiments, the baking conditions in Step S3 are: temperature 150 to 180 °C, time 2 to 5 minutes.

[0023] In yet another aspect, there is provided a foamed coated sunshade textile having a temperature regulation function prepared by the foregoing method.

[0024] Beneficial effects:

[0025] (1) First, the present invention utilizes the self-oxidative polymerization reaction of levodopa to obtain polydopamine nanoparticles with photothermal effects. Then, both polydopamine nanoparticles and polyethyleneimine are used to modify thermosensitive phase change microcapsules. During this process, the quinone groups formed by the self-oxidation of polydopamine nanoparticles can undergo Michael addition and Schiff base reactions with the amino groups in polyethyleneimine, thereby forming a dense network structure on the surface of the thermosensitive phase change microcapsules. Based on this dense network structure, the firmness of the wall of the thermosensitive phase change microcapsules can be significantly enhanced, avoiding the leakage of the phase change material inside the microcapsules and extending the service life of the thermosensitive phase change microcapsules. The polydopamine nanoparticles can improve the photothermal conversion efficiency and heat storage capacity of the thermosensitive phase change microcapsules.

[0026] (2) The present invention applies the modified thermosensitive phase change microcapsules to a foaming coating to construct a functional fiber-based sunshade material, and successfully obtains a fiber-based sunshade material with the functions of light absorption and heat storage under illumination and heat release and automatic temperature regulation at low temperatures. The modified thermosensitive phase change microcapsules prepared by the present invention have high photothermal conversion efficiency and heat storage capacity, and can be applied to the preparation of foaming coating sunshade textiles with excellent photothermal properties, heat storage and heat release properties, and temperature regulation functions. Compared with the preparation methods of traditional sunshade products, the modification process of the modified thermosensitive phase change microcapsules of the present invention is simple and the conditions are mild. Not only does it have a good automatic temperature regulation function after finishing, but also it has a lasting and stable finishing effect.

[0027] (3) The preparation method of the polydopamine nanoparticles / polyethyleneimine modified thermosensitive phase change microcapsules of the present invention is simple and the conditions are mild: During the preparation process of the polydopamine nanoparticles / polyethyleneimine modified thermosensitive phase change microcapsules, the main reagents are levodopa and polyethyleneimine. The reaction is carried out in an aqueous solution, with simple operation, no need for a high-temperature and high-pressure reactor, the reaction pH value is weakly alkaline, and the reaction can be carried out at room temperature with mild conditions.

[0028] (4) The usage method of the polydopamine nanoparticles / polyethyleneimine modified thermosensitive phase change microcapsules of the present invention is simple: By adding them to polyacrylate foaming slurry and then coating it on the fabric surface, a foaming coating sunshade textile with temperature regulation function can be obtained after baking. This method can directly utilize the existing foaming coating finishing equipment and reagents without adding new professional equipment and personnel.

[0029] (5) The polydopamine nanoparticles / polyethyleneimine modified thermosensitive phase change microcapsules of the present invention have a long service life: Compared with the unmodified thermosensitive phase change microcapsules, the firmness of the wall of the modified microcapsules is greatly improved, and the service life of the thermosensitive phase change microcapsules is extended. In addition, the thermosensitive phase change microcapsules are contained in the polyacrylate foaming coating and are difficult to fall off from the fabric, giving the sunshade textile a lasting and stable finishing effect. Detailed implementation mode

[0030] The embodiments of the present invention will be described below. It should be understood that the embodiments are for better explaining the present invention and are not used to limit the present invention.

[0031] Materials:

[0032] The thermosensitive phase change microcapsules involved in the present invention: the phase transition temperature is 5 - 40 °C, the shell material: polymethyl methacrylate (PMMA), and the core material: n - eicosane, a normal alkane.

[0033] The polyacrylate sizing agent involved in the present invention: purchased from Shanghai Baolijia New Materials Co., Ltd., model 776A, with a solids content of 50%. Other commercially available polyacrylate emulsions can also be used in the present invention.

[0034] The ammonium stearate emulsion involved in the present invention: purchased from Tongxiang Hongyuan Textile Auxiliary Factory, model DT - 100830C, with a solids content of 30%. Other commercially available ammonium stearate emulsions can also be used in the present invention.

[0035] The kerosene thickener involved in the present invention: any commercially available kerosene thickener can be used.

[0036] The fabric raw material involved in the present invention: pure polyester shuttle - woven fabric, 95 g / m 2 。

[0037] Testing methods:

[0038] (1) Fabric photothermal performance test under simulated sunlight : Using a xenon lamp to simulate sunlight, place a 10 cm × 10 cm fabric to be tested under the xenon lamp light source for 10 minutes. The radiation intensity of the xenon lamp illumination is 200 mW / cm 2 , and use a temperature sensor to record the surface temperature change of the fabric to be tested.

[0039] (2) Fabric heat storage and heat release performance test : Use a self - made device to test the heat storage and heat release performance of the fabric; the device is a 10 cm × 10 cm × 10 cm cube glass container with a temperature sensor inside; place a 10 cm × 10 cm fabric to be tested in this glass container, seal it, and place it under the xenon lamp light source for 10 minutes; then place this glass container in a 4 °C refrigerator and monitor the temperature change inside the glass container.

[0040] Example 1

[0041] A preparation method of a foamed - coated sun - shading textile with a temperature - regulating function includes the following steps:

[0042] I. Preparation of modified thermosensitive phase change microcapsules:

[0043] (1) Completely dissolve levodopa in an aqueous solution with a pH value of 8 to obtain a 1 g / L levodopa solution; stir the auto-oxidation polymerization reaction at 40 °C for 5 hours to obtain a poly-levodopa nanoparticle dispersion;

[0044] (2) Add polyethyleneimine with a molecular weight of 1800 and a thermosensitive phase change microcapsule with a core material phase transition temperature of 10 °C to the poly-levodopa nanoparticle dispersion to obtain a mixed system I. Among them, the concentration of poly-levodopa nanoparticles in the mixed system I is 0.5 g / L, the concentration of polyethyleneimine is 0.5 g / L, and the concentration of thermosensitive phase change microcapsules is 10 g / L; stir the mixed system I at 40 °C for 6 hours for co-deposition cross-linking reaction to obtain a poly-levodopa nanoparticle / polyethyleneimine modified thermosensitive phase change microcapsule dispersion;

[0045] (3) Freeze-dry the poly-levodopa nanoparticle / polyethyleneimine modified thermosensitive phase change microcapsule dispersion to obtain poly-levodopa nanoparticle / polyethyleneimine modified thermosensitive phase change microcapsule powder;

[0046] II. Preparation of a foamed coating sunshade textile with a temperature regulation function:

[0047] (1) Disperse the poly-levodopa nanoparticle / polyethyleneimine modified thermosensitive phase change microcapsule powder in an aqueous solution to obtain a poly-levodopa nanoparticle / polyethyleneimine modified thermosensitive phase change microcapsule dispersion; add polyacrylate sizing agent, ammonium stearate emulsion and kerosene thickener to the poly-levodopa nanoparticle / polyethyleneimine modified thermosensitive phase change microcapsule dispersion, adjust the pH value to 8 with ammonia water, and mix evenly to obtain a foamed coating finishing solution. Among them, the final concentration of poly-levodopa nanoparticle / polyethyleneimine modified thermosensitive phase change microcapsule powder in the foamed coating finishing solution is 2 g / L, the final concentration of polyacrylate is 30 g / L, the final concentration of ammonium stearate is 6 g / L, and the volume fraction of kerosene thickener is 2%;

[0048] (2) Foam the foamed coating finishing solution according to a foaming ratio of 1:3, and then coat it on the fabric surface according to a mass ratio of the foamed coating finishing solution to the fabric of 1:3, and bake it at 180 °C for 2 minutes to obtain a foamed coating sunshade textile with a temperature regulation function.

[0049] After testing, the foamed coating sunshade textile with a temperature regulation function in this example has a weight gain of 30 g / m relative to the original fabric 2 .

[0050] Example 2

[0051] A preparation method of a foamed coating sunshade textile with a temperature regulation function, including the following steps:

[0052] I. Preparation of modified thermosensitive phase change microcapsules:

[0053] (1) Completely dissolve levodopa in an aqueous solution with a pH value of 9 to obtain a 0.5 g / L levodopa solution; stir the auto-oxidative polymerization reaction at 30 °C for 8 hours to obtain a dispersion of poly-levodopa nanoparticles;

[0054] (2) Add polyethyleneimine with a molecular weight of 600 and thermosensitive phase change microcapsules with a core material phase transition temperature of 5 °C to the dispersion of poly-levodopa nanoparticles to obtain a mixed system I. Among them, the concentration of poly-levodopa nanoparticles in the mixed system I is 0.25 g / L, the concentration of polyethyleneimine is 0.25 g / L, and the concentration of thermosensitive phase change microcapsules is 5 g / L; stir the mixed system I at 50 °C for 6 hours for co-deposition crosslinking reaction to obtain a dispersion of poly-levodopa nanoparticles / polyethyleneimine modified thermosensitive phase change microcapsules;

[0055] (3) Lyophilize the dispersion of poly-levodopa nanoparticles / polyethyleneimine modified thermosensitive phase change microcapsules to obtain poly-levodopa nanoparticles / polyethyleneimine modified thermosensitive phase change microcapsule powder;

[0056] II. Preparation of a foamed coating sunshade textile with a temperature regulation function:

[0057] (1) Disperse the poly-levodopa nanoparticles / polyethyleneimine modified thermosensitive phase change microcapsule powder in an aqueous solution to obtain a dispersion of poly-levodopa nanoparticles / polyethyleneimine modified thermosensitive phase change microcapsules; add polyacrylate sizing agent, ammonium stearate emulsion and kerosene thickener to the dispersion of poly-levodopa nanoparticles / polyethyleneimine modified thermosensitive phase change microcapsules, adjust the pH value to 8 with ammonia water, and mix evenly to obtain a foamed coating finishing liquid. Among them, the final concentration of poly-levodopa nanoparticles / polyethyleneimine modified thermosensitive phase change microcapsule powder in the foamed coating finishing liquid is 1 g / L, the final concentration of polyacrylate is 30 g / L, the final concentration of ammonium stearate is 6 g / L, and the volume fraction of kerosene thickener is 2%;

[0058] (2) Foam the foamed coating finishing liquid according to a foaming ratio of 1:3.5, and then coat it on the fabric surface according to a mass ratio of the foamed coating finishing liquid to the fabric of 1:3, and bake it at 160 °C for 3 minutes to obtain a foamed coating sunshade textile with a temperature regulation function.

[0059] After testing, the foamed coating sunshade textile with a temperature regulation function in this example has a weight gain of 28 g / m compared with the original fabric 2 .

[0060] Example 3

[0061] A preparation method of a foamed coating sunshade textile with a temperature regulation function. Referring to Example 1, the difference is only that the relative amounts of poly-L-dopa nanoparticles, polyethyleneimine, and thermosensitive phase change microcapsules in the mixed system I are adjusted as shown in Table 1, and other steps and parameters remain unchanged.

[0062] Table 1 Concentrations of poly-L-dopa nanoparticles, polyethyleneimine, and thermosensitive phase change microcapsules in the mixed system I

[0063]

[0064] Example 4

[0065] A preparation method of a foamed coating sunshade textile with a temperature regulation function. Referring to Example 1, the difference is only that the thermosensitive phase change microcapsules are respectively replaced with thermosensitive phase change microcapsules with phase transition temperatures of 20 °C, 30 °C, and 40 °C, and other steps and parameters remain unchanged. Among them, Example 4-1 uses thermosensitive phase change microcapsules at 20 °C, Example 4-2 uses thermosensitive phase change microcapsules at 30 °C, and Example 4-3 uses thermosensitive phase change microcapsules at 40 °C.

[0066] Comparative Example 1: Compared with Example 1, no modified thermosensitive phase change microcapsules are added.

[0067] A preparation method of a foamed coating sunshade textile. Referring to Example 1, the difference is only that the addition of modified thermosensitive phase change microcapsules is omitted from the foamed coating finishing solution, and other steps and parameters remain unchanged.

[0068] Comparative Example 2: Compared with Example 1, the modified thermosensitive phase change microcapsules are replaced with unmodified thermosensitive phase change microcapsules.

[0069] A preparation method of a foamed coating sunshade textile. Referring to Example 1, the difference is only that the poly-L-dopa nanoparticles / polyethyleneimine modified thermosensitive phase change microcapsules are replaced with unmodified thermosensitive phase change microcapsules, and other steps and parameters remain unchanged.

[0070] Comparative Example 3: Polyethyleneimine in Example 1 is omitted.

[0071] A preparation method of a foamed coating sunshade textile. Referring to Example 1, the difference is only that polyethyleneimine in Example 1 is omitted, and other aspects are the same as in Example 1, obtaining poly-L-dopa nanoparticle modified thermosensitive phase change microcapsule powder and a foamed coating sunshade textile containing the same.

[0072] Comparative Example 4: Levodopa in Example 1 is omitted.

[0073] A preparation method of a foamed coating sunshade textile. Referring to Example 1, the difference is only that L - dopa in Example 1 is omitted, and the rest is the same as in Example 1, to obtain polyethyleneimine - modified thermosensitive phase - change microcapsule powder and a foamed coating sunshade textile containing it.

[0074] Comparative Example 5: Replace L - dopa in Example 1 with dopamine

[0075] A preparation method of a foamed coating sunshade textile. Referring to Example 1, the difference is only that L - dopa in Example 1 is replaced by dopamine, and the rest is the same as in Example 1, to obtain polydopamine nanoparticles / polyethyleneimine - modified thermosensitive phase - change microcapsule powder and a foamed coating sunshade textile containing it.

[0076] Comparative Example 6: Replace polyethyleneimine in Example 1 with hexamethylenediamine

[0077] A preparation method of a foamed coating sunshade textile. Referring to Example 1, the difference is only that polyethyleneimine in Example 1 is replaced by hexamethylenediamine, and the rest is the same as in Example 1, to obtain poly - L - dopa nanoparticles / hexamethylenediamine - modified thermosensitive phase - change microcapsule powder and a foamed coating sunshade textile containing it.

[0078] Comparative Example 7:

[0079] A preparation method of a foamed coating sunshade textile. Referring to Example 1, the difference is only that the final concentration of poly - L - dopa nanoparticles / polyethyleneimine - modified thermosensitive phase - change microcapsule powder in the foamed coating finishing liquid is 3 g / L, and the rest is the same as in Example 1, to obtain polydopamine nanoparticles / polyethyleneimine - modified thermosensitive phase - change microcapsule powder and a foamed coating sunshade textile containing it.

[0080] Measure the photothermal performance and heat storage and heat release performance of the foamed coating sunshade textile specimens in the above - mentioned examples and comparative examples, and the obtained data are listed in Table 2.

[0081] Table 2 Photothermal performance and heat storage and heat release performance of different foamed coating sunshade textiles

[0082]

[0083]

[0084] As can be seen from Table 1:

[0085] (1) L-DOPA and polyethyleneimine are used to modify the thermosensitive phase change microcapsules with a phase transition temperature range of 5-10 °C based on the specific method of the present invention, and the foamed coating sunshade textiles are prepared by the foamed coating finishing liquid with the specific formula of the present invention (Example 1, Example 2), which have both excellent and stable photothermal performance and heat storage and heat release performance: the surface temperature of the fabric can reach above 45 °C after 1 minute of illumination, and the surface temperature of the fabric can reach above 50 °C after 5 minutes of illumination; after heat storage and being placed in the refrigerator, the cooling rate of the space where it is located will be significantly slowed down, and the internal temperature of the glass container is above 12 °C after being placed in a 0-4 °C refrigerator for 1 minute; after being tested 100 times under the same conditions, the temperature change difference of the heat storage and heat release performance of the fabric compared with the first test is 0 °C.

[0086] (2) From the results of Comparative Example 1, it can be seen that when the thermosensitive phase change microcapsules are not added to the fabric foamed coating, the fabric has almost no heat storage and heat release ability, and after being placed in the refrigerator, the temperature in the glass container is close to 4 °C.

[0087] (3) From the results of Comparative Example 2, it can be seen that when unmodified thermosensitive phase change microcapsules are added to the fabric foamed coating, the heat storage and heat release ability and stability of the fabric are much worse than those of Example 1 and Example 2. After being placed in the refrigerator, the temperature in the glass container is 8 °C, but lower than that of Example 1 and Example 2.

[0088] (4) By comparing the results of Example 1, Example 2, Example 3-1 and Example 3-2, it can be seen that based on the method of the present invention, only when the concentration of poly-L-DOPA nanoparticles in the mixed system I is 0.25-1 g / L, the concentration of polyethyleneimine is 0.25-1 g / L, and the concentration of thermosensitive phase change microcapsules is 5-10 g / L, the prepared foamed coating sunshade textiles have both excellent and stable photothermal performance and heat storage and heat release performance: the surface temperature of the fabric can reach above 45 °C after 1 minute of illumination, and the surface temperature of the fabric can reach above 50 °C after 5 minutes of illumination; after heat storage and being placed in the refrigerator, the cooling rate of the space where it is located will be significantly slowed down, and the internal temperature of the glass container is above 12 °C after being placed in a 0-4 °C refrigerator for 1 minute; after being tested 100 times under the same conditions, the temperature change difference of the heat storage and heat release performance of the fabric compared with the first test is 0 °C. However, when the concentrations of L-DOPA nanoparticles and polyethyleneimine are lower than 0.25 g / L (for example, 0.1 g / L, that is, Example 3-1), the photothermal performance, heat storage performance and the stability of heat storage and heat release performance of the prepared foamed coating sunshade textiles all decrease significantly. When the concentration of thermosensitive phase change microcapsules is lower than 10 g / L (for example, 2 g / L, that is, Example 3-2), the photothermal performance and heat storage performance of the prepared foamed coating sunshade textiles both decrease significantly.

[0089] (5) By comparing Example 1, Example 2, Example 4-1, Example 4-2 and Example 4-3, it can be seen that based on the method of the present invention, only when using thermosensitive phase change microcapsules with a phase transition temperature range of 5-10°C, the foamed coating sunshade textile obtained, after heat storage and placed in the refrigerator, will significantly slow down the cooling rate of the space where it is located. After the glass container is placed in a 0-4°C refrigerator for 1 minute, the internal temperature is above 12°C; after 100 tests under the same conditions, the temperature change difference of the heat storage and heat release performance of the fabric compared with the first test is 0°C; however, when using thermosensitive phase change microcapsules with a phase transition temperature range above 10°C, the heat storage and heat release performance of the foamed coating sunshade textile obtained is significantly worse than that of Example 1 and Example 2: after being placed in the refrigerator, the temperature inside the glass container does not exceed 10°C, indicating that the phase transition temperature of the thermosensitive phase change microcapsules in the present invention is the key to affecting the heat storage and heat release ability of the fabric, and the phase transition temperature of the thermosensitive microcapsules needs to be in the range of 5-10°C.

[0090] (6) It can be seen from Comparative Example 3 and Comparative Example 4 that omitting polyethylenimine and levodopa in the modified thermosensitive phase change microcapsules is not conducive to the photothermal performance and heat storage and heat release ability of the foamed coating sunshade textile.

[0091] (7) It can be seen from Comparative Example 5 that after replacing levodopa with structurally similar dopamine, the photothermal performance, heat storage performance and stability of the heat storage and heat release performance of the foamed coating sunshade textile obtained are significantly decreased. It is confirmed that the selection of levodopa is crucial for achieving the technical effects of the present invention.

[0092] (8) It can be seen from Comparative Example 6 that after replacing polyethylenimine with another amino-containing compound hexamethylenediamine, the photothermal performance, heat storage performance and stability of the heat storage and heat release performance of the foamed coating sunshade textile obtained are significantly decreased. It is confirmed that the selection of polyethylenimine is crucial for achieving the technical effects of the present invention.

[0093] (9) It can be seen from Comparative Example 7 that when the final concentration of poly-L-dopa nanoparticles / polyethylenimine modified thermosensitive phase change microcapsule powder in the foamed coating finishing solution is increased to 3 g / L, the photothermal performance and heat storage and heat release performance of the fabric are not much different from those of Example 1, but at this time, the foamed coating on the fabric surface cracks, affecting the product quality. It is confirmed that the final concentration of poly-L-dopa nanoparticles / polyethylenimine modified thermosensitive phase change microcapsule powder in the foamed coating finishing solution being 1-2 g / L is crucial for achieving the technical effects of the present invention.

[0094] The above-provided examples are not intended to limit the scope covered by the present invention, nor are the described steps intended to limit their execution order. Obvious improvements made by those skilled in the art to the present invention in combination with the existing well-known common sense also fall within the protection scope defined by the claims of the present invention.

Claims

1. A preparation method of modified thermosensitive phase change microcapsules, characterized in that, It includes the following steps: (1) Completely dissolve levodopa in an aqueous solution with a pH value of 8 - 9 to obtain a levodopa solution with a concentration of 0.5 - 2 g / L; carry out a stirring autoxidation polymerization reaction at 20 - 80 °C for 2 - 24 h to obtain a polylevodopa nanoparticle dispersion; (2) Add polyethyleneimine with a molecular weight of 600 - 10,000 Da and a thermosensitive phase change microcapsule with a phase transition temperature range of 5 - 10 °C to the polylevodopa nanoparticle dispersion to obtain a mixed system I, wherein the concentration of polylevodopa nanoparticles in the mixed system I is 0.25 - 1 g / L, the concentration of polyethyleneimine is 0.25 - 1 g / L, and the concentration of the thermosensitive phase change microcapsule is 5 - 10 g / L; stir the mixed system I at 20 - 80 °C for a co - deposition cross - linking reaction for 2 - 24 h to obtain a polylevodopa nanoparticle / polyethyleneimine - modified thermosensitive phase change microcapsule dispersion; (3) Lyophilize the polylevodopa nanoparticle / polyethyleneimine - modified thermosensitive phase change microcapsule dispersion to obtain a polylevodopa nanoparticle / polyethyleneimine - modified thermosensitive phase change microcapsule powder.

2. The method according to claim 1, characterized in that, In the mixed system I, the concentration of polylevodopa nanoparticles is 0.25 - 0.5 g / L, the concentration of polyethyleneimine is 0.25 - 0.5 g / L, and the concentration of the thermosensitive phase change microcapsule is 5 - 10 g / L; and the mass ratio of polylevodopa nanoparticles, polyethyleneimine, and the thermosensitive phase change microcapsule is 1:1:

20.

3. The modified thermosensitive phase change microcapsule prepared by the method according to claim 1 or 2.

4. The application of the modified thermosensitive phase change microcapsule according to claim 3 in the preparation of a coated sun - shading textile with a temperature - regulating function.

5. A preparation method of a foamed coating sunshade textile with a temperature regulation function, characterized in that, It includes the following steps: Step S1: Prepare the polylevodopa nanoparticle / polyethyleneimine - modified thermosensitive phase change microcapsule powder according to the method described in claim 1 or 2; Step S2: Disperse the polylevodopa nanoparticle / polyethyleneimine - modified thermosensitive phase change microcapsule powder in an aqueous solution to obtain a polylevodopa nanoparticle / polyethyleneimine - modified thermosensitive phase change microcapsule dispersion; add a kerosene thickener, a polyacrylate sizing agent, and a foam - stabilizing agent emulsion to the polylevodopa nanoparticle / polyethyleneimine - modified thermosensitive phase change microcapsule dispersion, adjust the pH value to 8 - 9 with ammonia water, and mix evenly to obtain a foaming coating finishing liquid, wherein the final concentration of the polylevodopa nanoparticle / polyethyleneimine - modified thermosensitive phase change microcapsule powder in the foaming coating finishing liquid is 1 - 2 g / L, the final concentration of the polyacrylate is 20 - 30 g / L, the final concentration of the foam - stabilizing agent is 5 - 6 g / L, and the volume fraction of the kerosene thickener is 2 - 3%; Step S3: Foam the foaming coating finishing liquid, then coat it on the fabric surface, and bake it to obtain a foamed - coated sun - shading textile with a temperature - regulating function.

6. The method according to claim 5, wherein In step S2, the foam - stabilizing agent is ammonium stearate.

7. The method according to claim 5, characterized in that In step S3, the foaming ratio of the foaming coating finishing liquid is 1:3 - 1:

4.

8. The method according to claim 5, characterized in that, In step S3, the baking conditions are: temperature 150 - 180 °C, time 2 - 5 minutes.

9. The foamed - coated sun - shading textile with a temperature - regulating function prepared by the method according to any one of claims 5 to 8.

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