High-thermal-conductivity glass fiber reinforced phase change laminated plate and preparation method thereof

Abstract

The invention provides a high-thermal-conductivity glass fiber reinforced phase change laminated plate and a preparation method thereof.The preparation method comprises the steps that S1, expanded graphite and molten n-octadecane are mixed and then subjected to vacuum impregnation treatment, then molten n-alkane is added, and a second composite phase change material is obtained; s2, carrying out single-side modification on the glass fiber cloth by using a silane coupling agent, and coating the modified surface of the single-side modified glass fiber cloth with a second composite phase change material to form a temperature control coating; s3, mixing modified nano silicon dioxide, polyurethane acrylic resin and a silane coupling agent, and then coating the unmodified surface of the single-surface modified glass fiber cloth with the mixture to obtain double-surface modified glass fiber cloth; and S4, symmetrically overlapping the two layers of double-sided modified glass fiber cloth, and performing hot-pressing compounding to obtain the high-thermal-conductivity glass fiber reinforced phase change laminated plate. The problems of liquid phase leakage and low thermal conductivity of the phase change material are effectively solved through the synergistic enhancement effect of the expanded graphite and the glass fibers and the design of the barrier coating.

Description

Technical Field

[0001] The present invention belongs to the field of energy storage technology, and in particular relates to a high thermal conductivity glass fiber reinforced phase change laminate and a preparation method thereof. Background Art

[0002] With the rapid development of high-performance electronic devices such as 5G communications, artificial intelligence, consumer electronics, and new energy vehicles, the integration of electronic devices continues to increase. The resulting thermal management issues have become a key factor restricting the stable operation and reliable performance of equipment. As an emerging and efficient heat dissipation solution, thermally conductive phase change materials (PCMs) have become a research hotspot in the fields of energy science and materials science in recent years. Phase change materials (PCMs) are materials that absorb and release latent heat through reversible phase changes within a limited temperature range. Among them, organic phase change materials are widely used due to their high latent heat and wide phase change temperature range. Alkanes, fatty acids, and polyols are the three major organic-based phase change materials used for medium and low-temperature thermal energy storage. However, in actual application scenarios, organic-based phase change materials have exposed many scientific problems that need to be solved urgently, namely low thermal conductivity and easy leakage in the molten state.

[0003] To address these issues, existing materials can be modified through composite methods to improve the thermal conductivity of PCMs and mitigate material leakage. However, currently developed new phase change materials still face technical bottlenecks in simultaneously addressing the liquid phase leakage problem of organic phase change materials and improving their low thermal conductivity. Summary of the Invention

[0004] The purpose of the present invention is to provide a high thermal conductivity glass fiber reinforced phase change laminate and a preparation method thereof, so as to solve the problems of liquid phase leakage and low thermal conductivity of phase change materials and to enable the laminate to have excellent mechanical properties.

[0005] S1: uniformly mixing expanded graphite and molten n-octadecane to obtain a first mixture; performing vacuum impregnation treatment on the first mixture to obtain a first composite phase change material; adding molten n-alkane to the first composite phase change material to obtain a second composite phase change material;

[0006] S2: using a silane coupling agent to modify the glass fiber cloth on one side to obtain a single-side modified glass fiber cloth; and applying the second composite phase change material on the modified surface of the single-side modified glass fiber cloth by a roller coating process to form a temperature control coating;

[0007] S3: uniformly mixing the modified nano-silica, polyurethane acrylic resin, and silane coupling agent to obtain a second mixture, and applying the second mixture to the unmodified surface of the single-sided modified glass fiber cloth by a doctor blade coating process to form a barrier coating, thereby obtaining a double-sided modified glass fiber cloth;

[0008] S4, in the manner of the barrier coating facing outward and the temperature control coating facing inward, symmetrically laminating two layers of double-sided modified glass fiber cloth to perform hot pressing to form a primary laminated board; and then coating and sealing the side surface of the primary laminated board with epoxy resin to obtain a high-thermal-conductivity glass fiber reinforced phase change laminated board.

[0009] Specifically, the vacuum impregnation treatment in step S1 is to place the first mixture in a vacuum condition at 40-60℃ for 12-15h; the mass ratio of the expanded graphite, n-octadecane and n-alkane is 1:(5-10):(0.1-0.5).

[0010] Specifically, the expanded graphite in step S1 is prepared by high-temperature expansion treatment of graphite; the treatment temperature of the high-temperature expansion treatment is 900-1000℃, and the treatment time is 10-60s.

[0011] Specifically, the silane coupling agent in steps S2 and S3 is any one of KH570, KH550, KH792 and KH571.

[0012] Specifically, step S2 further comprises:

[0013] S21 adjusting the pH value of an ethanol aqueous solution to 3 using hydrochloric acid, then adding a silane coupling agent thereto, and continuously stirring at room temperature for 0.5-1h to obtain a coupling agent solution;

[0014] S22 immersing a glass fiber cloth on one side in the coupling agent solution, immersing for 0.5-1h, then taking out the glass fiber cloth and drying in a vacuum oven at 120℃ for 2-4h to obtain a glass fiber cloth modified on one side;

[0015] S23 and coating a second composite phase change material on the modified side of the glass fiber cloth modified on one side by a roll coating process, and cooling at room temperature for 10-30min to form a temperature control coating;

[0016] Specifically, the mass ratio of the modified nanosilica, the silane coupling agent and the polyurethane acrylic resin in step S3 is 1:1:50; and the preparation method of the second mixture comprises: mixing the modified nanosilica, the silane coupling agent and the polyurethane acrylic resin, and mechanically stirring at a speed of 800r / min for 20min to obtain the second mixture.

[0017] Specifically, the preparation method of the modified nanosilica in step S3 comprises: mixing modified isopropyl titanate and nanosilica, and stirring at a speed of 600-800r / min at 50-70℃ for 4h to obtain the modified nanosilica; and the mass ratio of the modified isopropyl titanate and the nanosilica is 1:10.

[0018] Specifically, the preparation method of the modified isopropyl trititanate in step S3 includes: adding anhydrous ethanol to isopropyl trititanate in increments of 10 mL every 30 minutes, stirring at 90° C. and 1000 r / min for 90 minutes to prepare the modified isopropyl trititanate.

[0019] Specifically, the pressure of the hot pressing compound in step S4 is 0.3-0.5 MPa, the time is 60 seconds, and the temperature is 80-90° C.; and the epoxy resin is bisphenol A type.

[0020] The second object of the present invention is to provide a high thermal conductivity glass fiber reinforced phase change laminate prepared by the preparation method described above.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) The present invention uses expanded graphite and n-octadecane to form a temperature-control coating, forming an efficient heat-conducting network within the phase change material, allowing heat to be conducted more quickly within the phase change material, thereby improving the thermal conductivity of the entire phase change laminate. A dense barrier coating formed by modified silica nanoparticles and polyurethane acrylic resin, with glass fiber cloth as a skeleton support, is prepared by hot pressing to obtain a high-thermal-conductivity glass fiber-reinforced phase change laminate. The laminate has the advantages of high thermal conductivity, high leakage resistance, excellent mechanical properties, good thermal stability, and good weather resistance.

[0023] (2) Expanded graphite has a large specific surface area and good adsorption properties. After being blended with molten n-octadecane and normal alkanes, it can effectively adsorb n-octadecane organic phase change material. When the phase change material changes from solid to liquid, expanded graphite can restrict its flow and prevent liquid leakage;

[0024] (3) After the glass fiber cloth is modified on one side with a silane coupling agent, the composite phase change material and the barrier material are coated on the two surfaces respectively, thereby enhancing the bonding force between the temperature control coating, the barrier coating and the glass fiber cloth, so that the phase change material forms a stable coating on the surface of the glass fiber cloth, further reducing the risk of liquid leakage; in addition, the glass fiber cloth has high strength and certain thermal conductivity. As a reinforcing material, it not only makes the phase change laminate have better mechanical stability and durability, but also can quickly transfer the heat in the phase change material, further improving the thermal conductivity of the phase change laminate;

[0025] (4) The present invention blends modified silica nanoparticles with polyurethane acrylic resin to form a dense barrier coating, which can effectively block direct contact between the phase change material and the external environment, and prevent leakage even when the phase change material is in a molten state, thereby further reducing the leakage rate of the composite phase change material; in addition, the barrier coating improves the weather resistance of the phase change laminate, so that it can still maintain good performance under different environmental conditions, extend the service life of the phase change laminate, and improve the thermal stability and functional durability of the composite material. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0027] Figure 1 Schematic diagram of the structure of the phase change laminate prepared in Example 1 of the present invention;

[0028] Figure 2 This is a schematic diagram of the process flow of preparing the first composite phase change material according to Example 1 of the present invention;

[0029] Figure 3 This is a DSC curve of the temperature control coating prepared in Example 1 of the present invention after 50 cooling-heating cycle experiments;

[0030] Figure 4 This is a comparison chart of the thermal conductivity of the phase change laminates prepared in Examples 1-3 of the present invention;

[0031] Figure 5 This is a histogram comparison of the leakage rates of the phase-change thermally conductive laminates prepared in Examples 1-3 of the present invention after 100 heating / cooling cycles. DETAILED DESCRIPTION

[0032] The following will combine the contents in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those commonly understood by technicians in the technical field of the present invention. The terms used in the description of the present invention are only for the purpose of describing specific embodiments and are not used to limit the present invention. The term "and / or" used in this specification includes any and all combinations of one or more related listed items. It should be understood that, unless otherwise specified, the various raw materials in the present invention can be obtained commercially.

[0033] Example 1

[0034] Figure 1 Schematic diagram of the structure of the phase change laminate prepared in Example 1 of the present invention; Figure 1 As shown, the laminate includes two glass fiber cloth layers, a temperature control coating fixed between the two glass fiber cloth layers, and a barrier coating on the outermost layers of the two glass fiber cloth layers. Figure 2 This is a schematic diagram of the process flow of the first composite phase change material prepared in Example 1 of the present invention; the specific preparation method is as follows:

[0035] S1: Place a beaker containing 10 g of n-octadecane in a 40°C constant temperature water bath until it is completely melted to obtain molten n-octadecane; mix 1 g of expanded graphite with 10 g of molten n-octadecane, place the mixture in a 40°C constant temperature water bath, and stir for 2 hours to obtain a first mixture a; vacuum impregnate the first mixture a at 40°C for 12 hours to obtain a first composite phase change material; add 0.5 g of molten n-alkane to the first composite phase change material to obtain a second composite phase change material a;

[0036] S2 uses hydrochloric acid solution to adjust the pH of 95% ethanol aqueous solution to 3, adds (2wt%) KH570, and stirs continuously at room temperature for 30 minutes to obtain a coupling agent solution a; immerses one side of a glass fiber cloth (size 15cm×15cm, thickness 0.5mm) in the coupling agent solution for 0.5 hours, takes out the glass fiber cloth a, and places it in a vacuum oven at 120°C for 2 hours to obtain a single-sided modified glass fiber cloth a; and applies the second composite phase change material a on the modified surface of the single-sided modified glass fiber cloth by a roller coating process, and cools at room temperature for 10 minutes to solidify the second composite phase change material a to form a temperature control coating a;

[0037] S3 first adds anhydrous ethanol to isopropyl trititanate in increments of 10 mL every 30 minutes, and stirs at 90°C and 1000 r / min for 90 minutes to synthesize modified isopropyl trititanate; 0.4 g of modified isopropyl trititanate and 4 g of nano-silica particles are mixed and stirred at 50°C and 600 r / min for 4 hours to obtain modified silica nanoparticles.

[0038] The present invention adds anhydrous ethanol to isopropyl trititanate to initiate an ester exchange reaction. The ethoxy groups in the ethanol replace the isopropoxy groups in the isopropyl trititanate, thereby adjusting the reactivity and steric hindrance of the titanate precursor. The surface of the nano-silica is rich in silanol groups, and the modified titanate molecules retain active alkoxy groups. Under heating conditions, these alkoxy groups undergo a condensation reaction with the silanol groups on the silica surface to form stable covalent bonds, providing a strong chemical connection between the inorganic particles and the organic modified layer. Modification of the nano-silica greatly improves the dispersion stability of the silica nanoparticles in the organic phase and significantly enhances the interfacial interaction with organic matrices such as polymers.

[0039] 0.2 g of modified nano-silica, 0.2 g of a silane coupling agent, and 10 g of a polyurethane acrylic resin were mixed and mechanically stirred in a beaker at 800 rpm for 20 min to obtain a second mixture a. The second mixture a was applied to the unmodified surface of the single-sided modified glass fiber cloth a by a doctor blade coating process to form a barrier coating a, thereby obtaining a double-sided modified glass fiber cloth a.

[0040] S4 symmetrically stacks two layers of double-sided modified glass fiber cloth a with the barrier coating facing outward and the temperature control coating facing inward, and then applies a pressure of 0.5 MPa at 80°C for hot pressing for 60 seconds to form a primary laminate a; then, bisphenol A epoxy resin is used to coat and seal the sides of the primary laminate a to obtain a high thermal conductivity glass fiber reinforced phase change laminate a.

[0041] from Figure 1A partial structural diagram of the medium-temperature control coating shows that n-octadecane is evenly distributed within the expanded graphite skeleton, while n-alkanes are distributed on the surface. Together, they form a temperature-control coating with high thermal conductivity and structural stability. Expanded graphite has a large specific surface area and excellent adsorption properties. When blended with molten n-octadecane and n-alkanes, it effectively adsorbs the organic phase change material (PCM). During the solid-to-liquid transition, the expanded graphite restricts its flow, preventing leakage. Furthermore, the expanded graphite and n-octadecane form a highly efficient thermal conductivity network within the PCM, enabling faster heat transfer through the material and improving the thermal conductivity of the entire PCM laminate. The addition of n-alkanes, which have a certain latent heat of phase change, increases the total latent heat of the PCM. The resulting temperature-control coating absorbs or releases more heat during the phase change process, thereby increasing the energy storage density of the entire system and enabling more efficient energy storage in the energy storage field.

[0042] Example 2

[0043] S1: Place a beaker containing 5 g of n-octadecane in a 40°C constant temperature water bath until it is completely melted to obtain molten n-octadecane; mix 1 g of expanded graphite with 5 g of molten n-octadecane, place the mixture in a 40°C constant temperature water bath, and stir for 2 hours to obtain a first mixture b; vacuum impregnate the first mixture b at 60°C for 15 hours to obtain a first composite phase change material; add 0.1 g of molten n-alkane to the first composite phase change material to obtain a second composite phase change material b;

[0044] S2 uses hydrochloric acid solution to adjust the pH of 95% ethanol aqueous solution to 3, adds (2wt%) KH550, and stirs continuously at room temperature for 1 hour to obtain a coupling agent solution b; immerses one side of a glass fiber cloth (size 15cm×15cm, thickness 0.5mm) in the coupling agent solution for 1 hour, takes out the glass fiber cloth b and places it in a vacuum oven at 120°C and dry it for 4 hours to obtain a single-sided modified glass fiber cloth b; and applies a second composite phase change material b to the modified surface of the single-sided modified glass fiber cloth by a roller coating process, and cools at room temperature for 30 minutes to solidify the second composite phase change material b to form a temperature control coating b;

[0045] S3: First, anhydrous ethanol is added to isopropyl trititanate in increments of 10 mL every 30 minutes, and the mixture is stirred at 90°C at a speed of 1000 r / min for 90 minutes to synthesize modified isopropyl trititanate; 0.4 g of modified isopropyl trititanate and 4 g of nano-silica particles are mixed and stirred at 70°C at a speed of 800 r / min for 4 hours to obtain modified silica nanoparticles. Then, 0.2 g of modified nano-silica, 0.2 g of silane coupling agent and 10 g of polyurethane acrylic resin are mixed and mechanically stirred in a beaker at a speed of 800 r / min for 20 minutes to obtain a second mixture b, which is applied to the unmodified surface of the single-sided modified glass fiber cloth b by a knife coating process to form a barrier coating b, thereby obtaining a double-sided modified glass fiber cloth b;

[0046] S4 symmetrically stacks two layers of double-sided modified glass fiber cloth b with the barrier coating facing outward and the temperature control coating facing inward, and then applies 0.3 MPa pressure at 90°C for 80 seconds to form a primary laminate b; then uses bisphenol A epoxy resin to coat and seal the side of the primary laminate b to obtain a high thermal conductivity glass fiber reinforced phase change laminate b.

[0047] Example 3

[0048] S1: Place a beaker containing 8 g of n-octadecane in a 40°C constant temperature water bath until it is completely melted to obtain molten n-octadecane; mix 1 g of expanded graphite with 5 g of molten n-octadecane, place the mixture in a 40°C constant temperature water bath, and stir for 2 hours to obtain a first mixture c; vacuum impregnate the first mixture c at 50°C for 14 hours to obtain a first composite phase change material; add 0.3 g of molten n-alkane to the first composite phase change material to obtain a second composite phase change material c;

[0049] S2 uses hydrochloric acid solution to adjust the pH of 95% ethanol aqueous solution to 3, adds (2wt%) KH792, and stirs continuously at room temperature for 50 minutes to obtain a coupling agent solution c; immerses one side of a glass fiber cloth (size 15cm×15cm, thickness 0.5mm) in the coupling agent solution for 50 minutes, takes out the glass fiber cloth c and places it in a vacuum oven at 120°C for 3 hours to obtain a single-sided modified glass fiber cloth c; and applies a second composite phase change material c to the modified surface of the single-sided modified glass fiber cloth by a roller coating process, and cools at room temperature for 20 minutes to solidify the second composite phase change material c to form a temperature control coating c;

[0050] S3: First, anhydrous ethanol is added to isopropyl trititanate in increments of 10 mL every 30 minutes, and the mixture is stirred at 90°C at a speed of 1000 r / min for 90 minutes to synthesize modified isopropyl trititanate; 0.4 g of modified isopropyl trititanate and 4 g of nano-silica particles are mixed and stirred at 60°C at a speed of 700 r / min for 4 hours to obtain modified silica nanoparticles. Then, 0.2 g of modified nano-silica, 0.2 g of silane coupling agent and 10 g of polyurethane acrylic resin are mixed and mechanically stirred at a speed of 800 r / min in a beaker for 20 minutes to obtain a second mixture c, which is applied to the unmodified surface of the single-sided modified glass fiber cloth c by a doctor blade process to form a barrier coating c, thereby obtaining a double-sided modified glass fiber cloth c;

[0051] S4 symmetrically stacks two layers of double-sided modified glass fiber cloth c with the barrier coating facing outward and the temperature control coating facing inward, and then applies a pressure of 0.4 MPa at 85°C for 70 seconds to form a primary laminate c; then, bisphenol A epoxy resin is used to coat and seal the sides of the primary laminate c to obtain a high thermal conductivity glass fiber reinforced phase change laminate c.

[0052] Example 4

[0053] S1: Place a beaker containing 8 g of n-octadecane in a 40°C constant temperature water bath until it is completely melted to obtain molten n-octadecane; mix 1 g of expanded graphite with 5 g of molten n-octadecane, place the mixture in a 40°C constant temperature water bath, and stir for 2 hours to obtain a first mixture d; vacuum impregnate the first mixture d at 40°C for 13 hours to obtain a first composite phase change material d; add 0.4 g of molten n-alkane to the first composite phase change material to obtain a second composite phase change material d;

[0054] S2 uses hydrochloric acid solution to adjust the pH of 95% ethanol aqueous solution to 3, adds (2wt%) KH571, and stirs continuously at room temperature for 30 minutes to obtain coupling agent solution d; immerses one side of glass fiber cloth (size 15cm×15cm, thickness 0.5mm) in coupling agent solution d for 40 minutes, takes out glass fiber cloth d and places it in a vacuum oven at 120°C for 4 hours to obtain single-side modified glass fiber cloth d; and applies the second composite phase change material d on the modified surface of the single-side modified glass fiber cloth d by roller coating, cools at room temperature for 10 minutes, and solidifies the second composite phase change material d to form a temperature control coating d;

[0055] S3: First, anhydrous ethanol was added to isopropyl trititanate in increments of 10 mL every 30 minutes, and the mixture was stirred at 90°C at a speed of 1000 r / min for 90 minutes to synthesize modified isopropyl trititanate; 0.4 g of modified isopropyl trititanate and 4 g of nano-silica particles were mixed and stirred at 60°C at a speed of 700 r / min for 4 hours to obtain modified silica nanoparticles. Then, 0.2 g of modified nano-silica, 0.2 g of silane coupling agent and 10 g of polyurethane acrylic resin were mixed and mechanically stirred in a beaker at a speed of 800 r / min for 20 minutes to obtain a second mixture d. The second mixture d was applied to the unmodified surface of the single-sided modified glass fiber cloth d by a knife coating process to form a barrier coating d, thereby obtaining a double-sided modified glass fiber cloth d.

[0056] S4 symmetrically stacks two layers of double-sided modified glass fiber cloth d with the barrier coating facing outward and the temperature control coating facing inward, and then applies a pressure of 0.5 MPa at 80°C for 60 seconds to form a primary laminate d; then, the sides of the primary laminate d are coated and sealed with bisphenol A epoxy resin to obtain a high thermal conductivity glass fiber reinforced phase change laminate d.

[0057] Comparative Example 1

[0058] The preparation method is the same as that of Example 1, except that the phase change laminate does not contain a barrier coating.

[0059] Comparative Example 2

[0060] The preparation method is the same as that of Example 1, except that the phase change coating in the phase change laminate does not contain expanded graphite.

[0061] Performance Testing

[0062] In order to demonstrate the effect of the prepared high thermal conductivity glass fiber reinforced phase change laminate in the field of temperature control, a temperature control test was conducted. The phase change laminate prepared in Example 1 was subjected to a DSC test. Figure 3 This is the DSC curve of the temperature-control coating prepared in Example 1 of the present invention after 50 cooling-heating cycles. Its endothermic peak temperature is 28.5°C, with an endothermic enthalpy of 172 J / g; its exothermic peak temperature is 26.6°C, with an exothermic enthalpy of 168 J / g. This shows that the temperature-control coating in this phase-change laminate has significantly improved thermal conductivity and possesses a high phase-change latent heat capacity.

[0063] To demonstrate the thermal conductivity of the prepared high-thermal-conductivity glass fiber-reinforced phase-change laminates, a transient planar heat source method thermal conductivity test was performed. Thermal conductivity testing: The phase-change laminates prepared in Examples 1-3 and Comparative Example 2 were cut into 3-cm-diameter discs and tested according to ASTM D5470-2006.

[0064] Figure 4 The thermal conductivity histogram comparison diagram of the phase change laminates prepared in Examples 1-3 of the present invention. Figure 4 As shown, the thermal conductivities of the phase change laminates prepared in Examples 1-3 were 4.92 W / (m·K), 4.76 W / (m·K), and 4.25 W / (m·K), respectively, representing a maximum improvement of 55.8% compared to the 2.17 W / (m·K) of the phase change laminate prepared in Comparative Example 2. Examples 1-3 and Comparative Example 2 demonstrate that the phase change laminates with the addition of expanded graphite have higher thermal conductivity, indicating that expanded graphite and molten n-octadecane synergistically enhance thermal conductivity.

[0065] To demonstrate the anti-leakage effectiveness of the prepared high-thermal-conductivity glass fiber-reinforced phase-change laminates, a leakage test was conducted. The phase-change laminates prepared in Examples 1-3 and Comparative Example 1 were placed in a high-low temperature cycling environment. After 100 cycles, leakage tests were conducted. The morphological changes of each phase-change laminate were observed, and the leakage rate was calculated based on the mass change. Figure 5 The following is a histogram comparing the leakage rates of the phase change thermal conductive laminates prepared in Examples 1-3 of the present invention after 100 heating / cooling cycles. The phase change laminate prepared in Comparative Example 1 has some liquid leakage on its surface after heating, while the phase change laminates prepared in Examples 1-3 have no liquid leakage. Figure 5 As shown, the leakage rates of the phase change laminates prepared in Examples 1-3 were 2.74%, 8.49%, and 2.91%, respectively. This indicates that the leakage rate of the phase change laminate containing the barrier coating can be reduced by up to 78%, compared to 16.2% for the phase change laminate prepared in Comparative Example 1. Examples 1-3 and Comparative Example 1 demonstrate that blending modified silica nanoparticles with a polyurethane acrylic resin to form a dense barrier coating effectively prevents direct contact between the phase change material and the external environment, further reducing the leakage rate of the composite phase change material even when the phase change material is molten.

[0066] In order to prove the mechanical properties of the prepared high thermal conductivity glass fiber reinforced phase change laminate, mechanical property tests were carried out. The mechanical properties were tested in accordance with GB / T1040.1-2006 and GB / T9639.1-2008. The tensile strengths of the phase change laminates prepared in Examples 1-3 and Comparative Examples 1-2 were 160MPa, 280MPa, 260MPa, 120MPa, and 90MPa, respectively. It can be seen that after the glass fiber cloth was modified on one side with a silane coupling agent, the bonding force between the temperature control coating, the barrier coating and the glass fiber cloth was enhanced. The glass fiber cloth was used as a reinforcing material, which made the phase change laminates prepared in Examples 1-3 have better mechanical stability and durability.

[0067] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A method for preparing a high thermal conductivity glass fiber reinforced phase change laminate, characterized in that: The following steps are involved: S1: uniformly mixing expanded graphite and molten n-octadecane to obtain a first mixture; performing vacuum impregnation treatment on the first mixture to obtain a first composite phase change material; adding molten n-alkane to the first composite phase change material to obtain a second composite phase change material; S2: using a silane coupling agent to modify the glass fiber cloth on one side to obtain a single-side modified glass fiber cloth; and applying the second composite phase change material on the modified surface of the single-side modified glass fiber cloth by a roller coating process to form a temperature control coating; S3: uniformly mixing the modified nano-silica, polyurethane acrylic resin, and silane coupling agent to obtain a second mixture, and applying the second mixture to the unmodified surface of the single-sided modified glass fiber cloth by a doctor blade coating process to form a barrier coating, thereby obtaining a double-sided modified glass fiber cloth; S4 symmetrically stacks two layers of double-sided modified glass fiber cloth with the barrier coating facing outward and the temperature control coating facing inward, and then performs hot pressing to form a primary laminate; then the sides of the primary laminate are coated and sealed with epoxy resin to obtain a high thermal conductivity glass fiber reinforced phase change laminate.

2. The preparation method according to claim 1, characterized in that The vacuum impregnation treatment in step S1 is to place the first mixture under vacuum conditions at 40-60° C. and impregnate for 12-15 hours; the mass ratio of the expanded graphite, n-octadecane and n-alkane is 1:(5-10):(0.1-0.5).

3. The preparation method according to claim 1, characterized in that The expanded graphite in step S1 is prepared by subjecting graphite to a high-temperature expansion treatment; the treatment temperature of the high-temperature expansion treatment is 900-1000° C., and the treatment time is 10-60 seconds.

4. The preparation method according to claim 1, characterized in that The silane coupling agent in steps S2 and S3 is any one of KH570, KH550, KH792 and KH571.

5. The preparation method according to claim 1, characterized in that Step S2 further comprises: S21: adjusting the pH value of the ethanol aqueous solution to 3 with hydrochloric acid, adding a silane coupling agent thereto, and continuously stirring at room temperature for 0.5-1 h to obtain a coupling agent solution; S22: immersing one side of the glass fiber cloth in the coupling agent solution for 0.5-1 hour, taking out the glass fiber cloth and drying it in a vacuum oven at 120° C. for 2-4 hours to obtain a single-sided modified glass fiber cloth; S23: coating the second composite phase change material on the modified surface of the single-sided modified glass fiber cloth through a roller coating process, and cooling at room temperature for 10-30 minutes to form a temperature control coating.

6. The preparation method according to claim 1, characterized in that The mass ratio of the modified nano-silica, silane coupling agent and polyurethane acrylic resin in step S3 is 1:1:50; the preparation method of the second mixture includes: mixing the modified nano-silica, silane coupling agent and polyurethane acrylic resin and mechanically stirring at a speed of 800 r / min for 20-30 minutes to obtain the second mixture.

7. The preparation method according to claim 1, characterized in that The preparation method of the modified nano-silica in step S3 includes: mixing modified isopropyl trititanate and nano-silica, and stirring at 50-70°C and a speed of 600-800 r / min for 4-6 hours to obtain modified nano-silica; the mass ratio of the modified isopropyl trititanate to nano-silica is 1:

10.

8. The preparation method according to claim 7, characterized in that The preparation method of the modified isopropyl trititanate in step S3 includes: adding anhydrous ethanol to isopropyl trititanate in increments of 10 mL every 30 minutes, stirring at 90° C. and 1000 r / min for 90 minutes to prepare the modified isopropyl trititanate.

9. The preparation method according to claim 1, characterized in that The hot pressing compounding in step S4 is performed at a pressure of 0.3-0.5 MPa, a time of 60-80 seconds, and a temperature of 80-90° C.; and the epoxy resin is bisphenol A type.

10. A high thermal conductivity glass fiber reinforced phase change laminate produced by the production method according to any one of claims 1 to 9.

Images