Preparation method of a phase change energy storage carbon-plastic composite material

Abstract

The present invention discloses a preparation method of a phase change energy storage carbon-plastic composite material, which comprises the following steps: Step 1, soak bamboo charcoal powder in absolute ethanol for ultrasonic cleaning, adjust the moisture content of the bamboo charcoal powder after drying, and then place the bamboo charcoal powder in a high-power microwave emission box for microwave blasting pretreatment; Step 2, mix polyethylene glycol 800 with bamboo charcoal powder, then immerse the bamboo charcoal powder adsorbed with polyethylene glycol in an isocyanate solution, filter and place it in an oven for heating; then grind and crush the reacted bamboo charcoal powder, and mix it with low-density polyethylene; Step 3, extrude the mixed powder materials with a twin-screw extruder, and crush the extrudate with a crusher; Step 4, cool the crushed particles after hot pressing to obtain a finished product of the phase change energy storage carbon-plastic composite material. The phase change energy storage carbon-plastic composite material prepared by the present invention not only has excellent heat storage and energy storage capabilities, but also has good mechanical properties, avoiding the problem of phase change material leakage.

Description

Technical Field

[0001] The present invention relates to the field of application of energy storage materials, and more particularly to a method for preparing a phase change energy storage carbon-plastic composite material. Background Art

[0002] With the development of economy and society, energy consumption has been increasing continuously. The steadily growing energy consumption accounts for two-thirds of the global greenhouse gas emissions. Therefore, how to reduce energy consumption has always been an issue explored by each country. And building energy consumption, as an important part of energy consumption, is receiving increasing attention. In order to alleviate building energy consumption, thermal energy storage (TES) technology, especially phase change materials (PCM), has been widely studied. Phase change energy storage materials refer to materials that can automatically absorb or release latent heat to the environment by using the phase state or structural changes of the materials themselves within a certain temperature range, thereby achieving the regulation of the environmental temperature. According to the different forms of phase change, phase change materials can be divided into solid-solid, solid-liquid, solid-gas, and liquid-vapor phase change materials. As a typical solid-liquid phase change material, polyethylene glycol (PEG) has the characteristics of high latent heat and small volume change. Nevertheless, the leakage problem during the phase change of polyethylene glycol still limits the application of solid-liquid phase change materials. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for preparing a phase change energy storage carbon-plastic composite material. The phase change energy storage carbon-plastic composite material prepared by the present invention not only has excellent heat storage and energy storage capabilities, but also has good mechanical properties, avoiding the problem of phase change material leakage.

[0004] The technical solution of the present invention is as follows: A method for preparing a phase change energy storage carbon-plastic composite material, comprising the following steps:

[0005] Step 1: Soak bamboo charcoal powder in absolute ethanol, place it in an ultrasonic cleaner at room temperature for cleaning, and then dry it to a constant weight; then place the dried bamboo charcoal powder in a constant temperature and humidity box to adjust the moisture content to 50-65%, and then place the humidity-adjusted bamboo charcoal powder in a high-power microwave emission box for microwave blasting pretreatment, with a power of 120-140 kW and a treatment time of 1-2 min;

[0006] Step 2: Mix 50-80% of polyethylene glycol 800 and 20-50% of the bamboo charcoal powder treated in Step 1 according to the mass ratio, then immerse the bamboo charcoal powder adsorbed with polyethylene glycol in an isocyanate solution for 5-10 min, filter it, and place it in an oven at 60-80 °C for heating for 20-30 min; then grind and crush the reacted bamboo charcoal powder to about 80-100 mesh, and mix it with low-density polyethylene; in the mixed powder, the mass fraction of low-density polyethylene is 50-70%;

[0007] Step 3: Extrude the mixed powder using a twin-screw extruder and crush the extrudate using a pulverizer.

[0008] Step 4: Cool the crushed particles after hot pressing to obtain the finished phase change energy storage carbon plastic composite.

[0009] For the preparation method of the above-mentioned phase change energy storage carbon plastic composite, in Step 1, the particle size of the bamboo charcoal powder is 50 - 200 mesh.

[0010] For the preparation method of the aforementioned phase change energy storage carbon plastic composite, in Step 1, after ultrasonic cleaning for 10 min, take out the cleaned bamboo charcoal for suction filtration, and place the suction-filtered bamboo charcoal powder in an oven at 105 °C and dry it to constant weight.

[0011] For the preparation method of the aforementioned phase change energy storage carbon plastic composite, in Step 2, the mass ratio of polyethylene glycol 800 is 50%, and the mass ratio of bamboo charcoal powder is 50%.

[0012] For the preparation method of the aforementioned phase change energy storage carbon plastic composite, in Step 2, in the mixed powder, the mass fraction of low-density polyethylene is 60%.

[0013] For the preparation method of the aforementioned phase change energy storage carbon plastic composite, in Step 2, the particle size of the low-density polyethylene is 80 - 150 mesh.

[0014] For the preparation method of the aforementioned phase change energy storage carbon plastic composite, in Step 3, the temperatures of each section of the extruder are 140 °C, 150 °C, and 160 °C respectively, and the main machine speed is 19.5 rpm.

[0015] For the preparation method of the aforementioned phase change energy storage carbon plastic composite, in Step 3, the length of the particles after being crushed by the pulverizer is about 1 - 5 mm.

[0016] For the preparation method of the aforementioned phase change energy storage carbon plastic composite, in Step 4, for the hot pressing, evenly spread the particles in a mold of 100×100×4 mm, place the mold on a hot press, preheat it at 175 °C for 5 min, then hot press it for 10 min under a pressure of 10 MPa, then take out the mold and place it on a cold press, and cold press it for 5 min at room temperature under a pressure of 10 MPa.

[0017] Compared with the prior art, the present invention uses bamboo charcoal powder as a carrier, and greatly improves the porosity of the bamboo charcoal powder by means of microwave blasting. Then, polyethylene glycol is impregnated into the bamboo charcoal by direct adsorption method, so that it is uniformly filled in the pores inside the charcoal powder. After that, isocyanate reacts with polyethylene glycol to generate polyurethane resin, thereby blocking the pores of the bamboo charcoal powder and completely preventing the leakage problem of polyethylene glycol during the phase change process. The present invention melts and blends bamboo charcoal powder with low-density polyethylene to achieve secondary encapsulation, and obtains a phase change energy storage carbon-plastic composite material capable of adjusting temperature. The phase change energy storage carbon-plastic composite material prepared by the present invention has excellent heat storage and energy storage capabilities, and its overall structure is plate-shaped. This method can solve the leakage problem of the phase change material, and at the same time, the mechanical properties can be improved by using the plate-shaped structure, thus expanding the scope of use. The present invention pre-treats bamboo charcoal powder by microwave blasting in a high-power microwave emission box, which greatly improves the porosity of the bamboo charcoal and facilitates the subsequent absorption of polyethylene glycol. The present invention immerses the bamboo charcoal powder adsorbed with polyethylene glycol into an isocyanate solution to form a polyurethane protective layer on the surface of the bamboo charcoal, blocking the pores on the surface of the bamboo charcoal and reducing the occurrence of leakage phenomena. Using the phase change energy storage carbon-plastic composite material of the present invention to design and develop new wooden household products capable of intelligent temperature regulation, heat storage and energy conservation is of great significance for the development of low-carbon and energy-saving building materials and the promotion of the transformation and upgrading of the wood industry. Description of the Drawings

[0018] Figure 1 It is a physical diagram of the finished product in Example 4;

[0019] Figure 2 It is a graph of the heat absorption and release performance (DSC) of the phase change energy storage carbon-plastic composite material prepared in Example 4 and the ordinary carbon-plastic composite material;

[0020] Figure 3 It is a thermogravimetric analysis (TG) graph of each test object,

[0021] Figure 4 It is the test result of the temperature change of the phase change energy storage carbon-plastic composite material prepared in Example 4 and the ordinary carbon-plastic composite material. Detailed Embodiments

[0022] The following further illustrates the present invention in conjunction with the drawings and embodiments, but it is not used as a basis for limiting the present invention.

[0023] Example 1: A preparation method of a phase change energy storage carbon-plastic composite material, comprising the following steps:

[0024] Step 1: Soak bamboo charcoal powder in absolute ethanol, place it in an ultrasonic cleaner for cleaning at room temperature, and then dry it to a constant weight. Then, place the dried bamboo charcoal powder in a constant temperature and humidity chamber to adjust the moisture content to 55%. Next, place the humidity-adjusted bamboo charcoal powder in a high-power microwave emission chamber for microwave blasting pretreatment at a power of 120 kW and a treatment time of 1.5 min.

[0025] Step 2: Mix 60% polyethylene glycol 800 and 40% bamboo charcoal powder by mass ratio. Then, immerse the bamboo charcoal powder adsorbed with polyethylene glycol in the isocyanate solution for 8 min. After filtration, place it in an oven and heat it at 65 °C for 25 min. Then, grind and crush the reacted bamboo charcoal powder to about 100 mesh, and mix it with low-density polyethylene. In the mixed powder, the mass fraction of low-density polyethylene is 55%.

[0026] Step 3: Extrude the mixed powder with a twin-screw extruder, and crush the extrudate with a crusher.

[0027] Step 4: Cool the crushed particles after hot pressing to obtain the finished product of the phase change energy storage carbon plastic composite.

[0028] Example 2: A preparation method of a phase change energy storage carbon plastic composite, including the following steps:

[0029] Step 1: Soak bamboo charcoal powder with a particle size of 80 mesh in absolute ethanol, place it in an ultrasonic cleaner for cleaning for 10 min at room temperature, take out the cleaned bamboo charcoal for suction filtration, and place the suction-filtered bamboo charcoal powder in an oven at 105 °C for drying to a constant weight. Then, place the dried bamboo charcoal powder in a constant temperature and humidity chamber to adjust the moisture content to 60%. Next, place the humidity-adjusted bamboo charcoal powder in a high-power microwave emission chamber for microwave blasting pretreatment at a power of 140 kW and a treatment time of 2 min.

[0030] Step 2: Mix 50% polyethylene glycol 800 and 50% bamboo charcoal powder by mass ratio. Then, immerse the bamboo charcoal powder adsorbed with polyethylene glycol in the isocyanate solution for 5 - 10 min. After filtration, place it in an oven and heat it at 60 - 80 °C for 20 - 30 min. Then, grind and crush the reacted bamboo charcoal powder to about 80 mesh, and mix it with low-density polyethylene. In the mixed powder, the mass fraction of low-density polyethylene is 70%; the particle size of low-density polyethylene powder is 100 mesh.

[0031] Step 3: Extrude the mixed powder with a twin-screw extruder, and crush the extrudate with a crusher. The temperatures of each section of the extruder are 140 °C, 150 °C, and 160 °C respectively, and the main machine speed is 19.5 rpm; the length of the particles after crushing by the crusher is about 1 - 5 mm.

[0032] Step 4: Cool the crushed particles after hot pressing to obtain the finished phase change energy storage carbon-plastic composite material. For hot pressing, evenly spread the particles in a mold of 100×100×4 mm, place the mold on a hot press, preheat it at 175°C for 5 min, then hot press it under a pressure of 10 MPa for 10 min. After that, take out the mold and place it on a cold press, and cold press it at room temperature for 5 min with a pressure of 10 MPa.

[0033] Example 3: A preparation method of a phase change energy storage carbon-plastic composite material, comprising the following steps:

[0034] Step 1: Immerse bamboo charcoal powder with a particle size of 150 mesh in absolute ethanol, place it in an ultrasonic cleaner at room temperature for 10 min, take out the cleaned bamboo charcoal for suction filtration, and place the suction-filtered bamboo charcoal powder in an oven at 105°C to dry to constant weight; then place the dried bamboo charcoal powder in a constant temperature and humidity box to adjust the moisture content to 55%, and then place the humidity-adjusted bamboo charcoal powder in a high-power microwave emission box for microwave blasting pretreatment with a power of 125 kW and a treatment time of 1 min;

[0035] Step 2: Mix 50% of polyethylene glycol 800 and 50% of bamboo charcoal powder by mass ratio, then immerse the polyethylene glycol-adsorbed bamboo charcoal powder in an isocyanate solution for 5 - 10 min, filter it, and place it in an oven to heat at 60 - 80°C for 20 - 30 min; then grind and crush the reacted bamboo charcoal powder to about 90 mesh, and mix it with low-density polyethylene; in the mixed powder, the mass fraction of low-density polyethylene is 65%; the particle diameter of low-density polyethylene powder is 120 mesh;

[0036] Step 3: Extrude the mixed powder with a twin-screw extruder, and crush the extrudate with a crusher; the temperatures of each section of the extruder are 140°C, 150°C, and 160°C respectively, and the main machine speed is 19.5 rpm; the length of the particles after being crushed by the crusher is about 1 - 5 mm.

[0037] Step 4: Cool the crushed particles after hot pressing to obtain the finished phase change energy storage carbon-plastic composite material. For hot pressing, evenly spread the particles in a mold of 100×100×4 mm, place the mold on a hot press, preheat it at 175°C for 5 min, then hot press it under a pressure of 10 MPa for 10 min. After that, take out the mold and place it on a cold press, and cold press it at room temperature for 5 min with a pressure of 10 MPa.

[0038] Example 4: A preparation method of a phase change energy storage carbon-plastic composite material, comprising the following steps:

[0039] Step 1: Soak bamboo charcoal powder with a particle size of 100 mesh in absolute ethanol, place it in an ultrasonic cleaner at room temperature for 10 min, take out the cleaned bamboo charcoal for suction filtration, and place the filtered bamboo charcoal powder in an oven at 105 °C to dry to constant weight; then place the dried bamboo charcoal powder in a constant temperature and humidity box to adjust the moisture content to 60%, and then place the humidity-adjusted bamboo charcoal powder in a high-power microwave emission box for microwave blasting pretreatment with a power of 130 kW and a treatment time of 1 - 2 min;

[0040] Step 2: Mix 50% of polyethylene glycol 800 and 50% of bamboo charcoal powder by mass ratio, then immerse the bamboo charcoal powder adsorbed with polyethylene glycol in the isocyanate solution for 5 - 10 min, filter it, and place it in an oven to heat at 60 - 80 °C for 20 - 30 min; then grind and crush the reacted bamboo charcoal powder to about 80 - 100 mesh, and mix it with low-density polyethylene; in the mixed powder, the mass fraction of low-density polyethylene is 60%; the particle diameter of low-density polyethylene powder is 150 mesh;

[0041] Step 3: Extrude the mixed powder with a twin-screw extruder, and crush the extrudate with a crusher; the temperatures of each section of the extruder are 140 °C, 150 °C, and 160 °C respectively, and the main machine speed is 19.5 rpm; the length of the particles after crushing by the crusher is about 1 - 5 mm.

[0042] Step 4: Cool the crushed particles after hot pressing to obtain the finished product of the phase change energy storage carbon-plastic composite material. The hot pressing is to evenly spread the particles in a mold of 100×100×4 mm, place the mold on a hot press, preheat it at 175 °C for 5 min, then hot press it for 10 min under a pressure of 10 MPa, then take out the mold and place it on a cold press, and cold press it for 5 min at room temperature with a pressure of 10 MPa.

[0043] The applicant takes the finished product in the most preferred Example 4 as an example, and the physical diagram is as Figure 1 shown. As can be seen from Figure 1 , the phase change energy storage carbon-plastic composite material prepared by the present invention as a whole presents a plate-like structure. This method can solve the leakage problem of the phase change material, and at the same time, the mechanical properties can be improved by using the plate-like structure, expanding the scope of use. At the same time, the applicant conducts the endothermic and exothermic performance (DSC) test on this finished product and the ordinary carbon-plastic composite material, and the results are as Figure 2 shown. As can be seen from Figure 2 , the endothermic and exothermic performance of the phase change energy storage carbon-plastic composite material prepared by the present invention has been greatly improved compared with the ordinary carbon-plastic composite material. Figure 3 is the thermogravimetric analysis (TG) diagram of each test object. As can be seen from Figure 3As can be seen, the phase change energy storage carbon-plastic composite material prepared by the present invention is closer to polyethylene glycol in terms of heat, indicating that after the bamboo charcoal powder is used to adsorb polyethylene glycol 800 in the present invention and then mixed with low-density polyethylene to form a plate-shaped phase change energy storage carbon-plastic composite material, it has a stronger ability to store heat and energy. Figure 4 is the test result of the temperature change of the phase change energy storage carbon-plastic composite material of the present invention and the ordinary carbon-plastic composite material. From Figure 4 As can be seen, whether it is the heating or cooling process, the phase change energy storage carbon-plastic composite material of the present invention is more stable in terms of temperature change, indicating that its heat storage and heat release effects are excellent.

[0044] To sum up, the present invention uses bamboo charcoal powder as a carrier, impregnates polyethylene glycol into the bamboo charcoal by the direct adsorption method, makes it uniformly fill the pores inside the charcoal powder, and then melts and blends it with low-density polyethylene for secondary encapsulation to obtain a phase change energy storage carbon-plastic composite material that can adjust the temperature. The phase change energy storage carbon-plastic composite material prepared by the present invention has excellent heat storage and energy storage capabilities, and its overall structure is plate-shaped, with good mechanical properties, and can avoid the leakage of the phase change material, expanding the scope of use. Using the phase change energy storage carbon-plastic composite material of the present invention to design and develop new wooden household products that can intelligently adjust temperature, store heat and save energy is of great significance for developing low-carbon and energy-saving building materials and promoting the transformation and upgrading of the wood industry.

Claims

1. A method for preparing a phase-change energy storage carbon-plastic composite material, characterized by: The steps include: Step 1, soaking bamboo charcoal powder in anhydrous ethanol, placing it in an ultrasonic cleaner at room temperature for cleaning, and then drying it to constant weight; then placing the dried bamboo charcoal powder in a constant temperature and humidity chamber to adjust the moisture content to 50-65%, and then placing the moisture-adjusted bamboo charcoal powder in a high-power microwave transmission chamber for microwave explosion pretreatment at a power of 120-140 kW for 1-2 minutes; Step 2: Mixing 50-80% polyethylene glycol 800 with 20-50% of the bamboo charcoal powder treated in Step 1 according to a mass ratio, then immersing the polyethylene glycol-adsorbed bamboo charcoal powder in an isocyanate solution for 5-10 minutes, filtering, and heating in an oven at 60-80°C for 20-30 minutes; then grinding the reacted bamboo charcoal powder to approximately 80-100 mesh and mixing it with low-density polyethylene; the mass fraction of the low-density polyethylene in the mixed powder is 50-70%; Step 3: Extruding the mixed powder using a twin-screw extruder and crushing the extrudate using a crusher; Step 4: hot-pressing and then cooling the crushed particles to obtain a finished phase-change energy storage carbon-plastic composite material.

2. The method for preparing the phase-change energy storage carbon-plastic composite material according to claim 1, characterized in that: In step 1, the particle size of the bamboo charcoal powder is 50-200 meshes.

3. The method for preparing the phase-change energy storage carbon-plastic composite material according to claim 1, characterized in that: In step 1, after cleaning with an ultrasonic cleaner for 10 minutes, the cleaned bamboo charcoal is taken out and filtered, and the filtered bamboo charcoal powder is placed in an oven at 105° C. and dried to constant weight.

4. The method for preparing the phase-change energy storage carbon-plastic composite material according to claim 1, characterized in that: In step 2, the mass ratio of polyethylene glycol 800 is 50%, and the mass ratio of bamboo charcoal powder is 50%.

5. The method for preparing the phase-change energy storage carbon-plastic composite material according to claim 1, characterized in that: In step 2, the mass fraction of low-density polyethylene in the mixed powder is 60%.

6. The method for preparing the phase-change energy storage carbon-plastic composite material according to claim 1, characterized in that: In step 2, the low-density polyethylene powder has a diameter of 80-150 mesh.

7. The method for preparing the phase-change energy storage carbon-plastic composite material according to claim 1, characterized in that: In step 3, the temperatures of the various sections of the extruder were 140° C., 150° C., and 160° C., respectively, and the main engine speed was 19.5 rpm.

8. The method for preparing the phase-change energy storage carbon-plastic composite material according to claim 1, characterized in that: In step 3, the length of the particles after being crushed by the crusher is about 1 to 5 mm.

9. The method for preparing the phase-change energy storage carbon-plastic composite material according to claim 8, characterized in that: In step 4, the hot pressing is to evenly spread the particles in a 100×100×4 mm mold, place the mold on a hot press, preheat it at 175°C for 5 minutes, and then hot press it at a pressure of 10 MPa for 10 minutes. After that, take out the mold and place it on a cold press, and cold press it at room temperature for 5 minutes at a pressure of 10 MPa.

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