Multicomponent phase change material flame retardant, method for preparing same, and use thereof
By designing a core-shell structure for a multi-component phase change material flame retardant, the problem of decreased mechanical properties caused by large amounts of flame retardant added in existing technologies has been solved, achieving high-efficiency flame retardancy and improved thermal stability, resulting in a synergistic flame retardant effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA ACAD OF SAFETY SCI & TECH
- Filing Date
- 2023-04-03
- Publication Date
- 2026-05-22
AI Technical Summary
Existing phosphorus-based flame retardants, when added in large quantities, lead to a decline in the mechanical properties of composite materials. Existing phase change materials have imperfect component settings, making it impossible to maintain the mechanical properties of materials while achieving high-efficiency flame retardancy.
A multi-component phase change material flame retardant is adopted, which is composed of phase change material, nano flame retardant and traditional flame retardant to form a core-shell structure. The traditional flame retardant is the core and the nano flame retardant is the shell. The synergistic effect of each component is optimized through specific ratios and preparation methods to form a coating structure.
It achieves a highly efficient flame retardant effect while maintaining or improving the thermal stability and mechanical properties of the material. By modifying the phase change material with nano flame retardants, the flame retardant mechanisms of the gas phase and condensed phase are synergistically utilized, thus optimizing the flame retardant performance.
Smart Images
Figure CN116535745B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of flame retardant technology, and in particular to a multi-component phase change material flame retardant, its preparation method, and its application. Background Technology
[0002] Phase change materials (PCMs) are defined as substances that change state with temperature and also provide latent heat. This physical property transformation process is called a phase change process, during which PCMs absorb or release a large amount of latent heat. Utilizing the endothermic property of PCMs changing from a solid to a liquid state, they have been introduced into the field of flame retardancy. The structure and recyclability of PCMs respond to green, environmentally friendly, and sustainable development initiatives, and have broad application prospects.
[0003] Phosphorus-based flame retardants, such as ammonium polyphosphate, exhibit highly efficient flame-retardant effects, effectively reducing the heat and smoke release of composite materials and significantly enhancing the strength of the protective char layer while increasing residual char content. However, these excellent flame retardants still have significant drawbacks. While high dosages of phosphorus-based flame retardants are necessary to achieve such high efficiency, large dosages of inorganic flame retardants can significantly reduce the mechanical properties of composite materials. Therefore, how to avoid or minimize the deterioration of mechanical properties while ensuring efficient flame retardancy has become a key research focus.
[0004] Chinese invention patent publication CN111154229A discloses a flame-retardant phase change material film, applying phase change materials to flame retardancy, but its component and structural settings are not perfect. Chinese invention patent publication CN104592947A discloses a flame-retardant organic phase change material and its preparation method, mixing carbon nanotubes, organic phase change materials, and organic solvents, but its combination method is not perfect. Summary of the Invention
[0005] In view of the problems existing in the prior art, the present invention provides a multi-component phase change material flame retardant, its preparation method and application.
[0006] This invention is achieved through the following technical solution:
[0007] This invention provides a multi-component phase change material flame retardant, which is a flame retardant composed of phase change material, nano flame retardant and traditional flame retardant.
[0008] The core structure is a traditional flame retardant, while the shell structure is a phase change material doped with nano flame retardants.
[0009] Furthermore, the conventional flame retardant is one or more of aluminum hydroxide (ATH), ammonium polyphosphate (APP), dicyandiamide (DCD), expanded graphite (EG), melamine cyanurate (MCA), magnesium hydroxide (MDH), melamine (MEL), melamine polyphosphate (MPP), and pentaerythritol (PER).
[0010] Furthermore, the nano flame retardant is one or more of MXene, graphene (GNS), graphene oxide (GO), and carbon nanotubes (CNT).
[0011] Furthermore, the phase change material is paraffin.
[0012] Furthermore, the mass ratio of the paraffin wax, nano flame retardant, and traditional flame retardant is 1-5:1-3:1-20.
[0013] Furthermore, the preparation method of the multi-component phase change material flame retardant specifically includes the following steps:
[0014] (1) Place the phase change material in a container (three-necked flask) equipped with a stirrer and place it in a constant temperature water bath until it becomes completely liquid. Then, while stirring, slowly add the nano flame retardant into the flask until it is completely mixed.
[0015] (2) At room temperature, place the traditional flame retardant in a beaker, and slowly add the product from step (1) multiple times while continuously and vigorously stirring the mixture to ensure that the phase change material fully coats the traditional flame retardant particles.
[0016] Further, step (1) includes bathing the phase change material paraffin in a constant temperature water bath at 70-150°C for 30-90 minutes.
[0017] Furthermore, step (1) includes cooling the phase change material paraffin to 50-90°C after melting.
[0018] Further, step (1) includes mixing with the nano flame retardant and stirring for 20 to 60 minutes.
[0019] Further, step (2) includes coating conditions of room temperature of 10-25°C, continuous strong stirring before the phase change material is completely solidified, and the stirring speed of the strong stirring is 600-1200 r / min.
[0020] The slow, multiple additions in step (2) specifically involve first adding 1-88% (preferably 2-80%, more preferably 15-80%) of the mixed product into the container within 5-30 minutes, and then adding the remaining mixed product into the container in 2-12 portions, with each addition taking 1-10 minutes.
[0021] Furthermore, the application of the aforementioned multi-component phase change material flame retardant in polymer flame retardancy.
[0022] Furthermore, the polymer is one or more of epoxy resin, polyester, and polyolefin materials, and the amount of the multi-component phase change material flame retardant added is 1-20 wt.%.
[0023] Furthermore, the preparation method of the MXene is as follows:
[0024] (1) First, place concentrated hydrochloric acid and ultrapure water in a container (e.g., polytetrafluoroethylene plastic) to prepare an 8-10M hydrochloric acid solution, and place the container in an oil bath.
[0025] (2) LiF and Ti3AlC2 are slowly added to the hydrochloric acid solution prepared in step (1) in multiple steps, and the reaction is continued at 30-40℃ for 24-72h. The mass ratio of LiF to Ti3AlC2 is (1-2):(1-2).
[0026] (3) After the reaction is complete, the product obtained in step (2) is centrifuged and the solid is washed with deionized water several times until the pH of the supernatant is 6.5 to 7.5.
[0027] (4) Disperse the precipitate obtained in step (3) in deionized water by ultrasonication for 1.5 to 2.5 h to obtain MXene suspension.
[0028] (5) Centrifuge the MXene suspension from step (4) for 20-30 minutes using a centrifuge (3000-3800 r / min) and take the supernatant for later use.
[0029] (6) The product obtained in step (5) is placed in a freeze dryer and freeze-dried for 40-55 hours to finally obtain the MXene product.
[0030] Furthermore, the preparation method of the oxidized graphene (GO) is as follows:
[0031] (1) Add concentrated sulfuric acid to a container (e.g., a beaker) and place it in an ice-water bath until the temperature is -1 to 2°C.
[0032] (2) During continuous stirring, graphite powder and sodium nitrate are slowly added to the liquid in step (1) in multiple steps, wherein the ratio of graphite powder: sodium nitrate: concentrated sulfuric acid is (1.2~1.8g): (0.5~0.9g): (30~40mL), and the system temperature is kept below 3~6℃ during this process.
[0033] (3) After thoroughly stirring the mixture in step (2), potassium permanganate is slowly added to the mixture obtained in step (2) in multiple batches. The mass ratio of potassium permanganate to graphite powder is (2.5~3.5):1. During this process, the system temperature is kept at 0~5℃.
[0034] (4) Transfer the mixed solution obtained in step (3) to a water bath, heat it to 30-38°C, and stir continuously for 0.3-0.8 hours.
[0035] (5) Slowly add deionized water (1.5 to 2.5 times the volume of concentrated sulfuric acid) to the mixed solution obtained in step (4), and adjust the temperature to 90 to 105°C and react for 12 to 18 minutes.
[0036] (6) After the reaction is complete, cool the mixture in a water bath for 8 to 15 minutes. Then add 28 to 35% hydrogen peroxide solution and deionized water to the mixed solution in sequence. The volume ratio of hydrogen peroxide solution: deionized water: concentrated sulfuric acid is (18 to 22): (410 to 430): (32 to 38).
[0037] (7) Then cool the mixture obtained in step (6) to room temperature, centrifuge and wash several times until SO4 is reached. 2- The product is cleaned and then vacuum dried at 55–65°C to obtain graphene oxide (GO).
[0038] Preferably, the polymer is rigid polyurethane (RPUF).
[0039] The beneficial effects of this invention are:
[0040] This invention coats a phase change material mixed with nano-flame retardants onto the surface of a phosphorus-based flame retardant. By modifying the phase change material with nano-flame retardants, a traditional flame retardant is physically coated, forming a double-layer core-shell structure, thus preparing a surface-coated flame-retardant phase change material. This combines the performance advantages of the phase change material (paraffin), nano-flame retardants, and traditional flame retardants. Furthermore, the specific design and close coordination of each core-shell component through the preparation method ensures that the performance advantages of each part are not individually apparent, but rather achieve a highly efficient synergistic effect (superior to the effect of each component alone). The synergistic flame retardancy of multiple flame-retardant elements fully utilizes the flame-retardant mechanisms of the gas phase and condensed phase, exhibiting excellent thermal stability and flame-retardant performance.
[0041] By combining nano flame retardants with phase change materials, the drawbacks of phase change materials are mitigated, and the energy storage function of phase change materials is fully utilized. In the early stage of a fire, heat energy is absorbed through phase change, reducing the temperature of the burning material and effectively inhibiting the combustion and development of the flame. In conjunction with traditional flame retardants, they work together in polymers, exhibiting excellent thermal stability and flame retardant properties, providing new ideas for flame retardant applications.
[0042] This invention achieves an optimal combination by specifically defining the proportions of each component, specifically defining the coating structure, and optimizing and setting various parameters in the preparation process, so that the resulting coating structure can optimize the synergistic advantages of the above-mentioned multi-components while offsetting their respective disadvantages. Attached Figure Description
[0043] Figure 1 This is a schematic diagram of the structure of the multi-component phase change material flame retardant of the present invention.
[0044] Among them, 1-phase change material part, 2-traditional flame retardant part, 3-nano flame retardant part. Detailed Implementation
[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described 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 those skilled in the art without creative effort are within the scope of protection of the present invention.
[0046] like Figure 1 The example shown illustrates this, where the nano-flame retardant and phase change material portions are located in the shell layer, while the traditional flame retardant forms the core. Figure 1 This is a schematic diagram of semi-perspective.
[0047] Example 1
[0048] This embodiment provides a multi-component core-shell structured flame retardant, which is paraffin (PW) and MXene-coated ammonium polyphosphate (APP).
[0049] This embodiment also provides a method for preparing the above-mentioned multi-component core-shell structure flame retardant, the specific steps of which are as follows:
[0050] (1) First, place concentrated hydrochloric acid and ultrapure water in a polytetrafluoroethylene plastic container to prepare a 9M hydrochloric acid solution, and place the container in an oil bath.
[0051] (2) Add 1g LiF and 1g Ti3AlC2 slowly and repeatedly to the hydrochloric acid solution prepared in step (1), and continue to react at 35°C for 48h.
[0052] (3) After the reaction is complete, the product from step (2) is centrifuged and washed with deionized water several times until the pH of the supernatant is approximately 7.
[0053] (4) The precipitate obtained in step (3) is ultrasonically dispersed in deionized water for 2 hours to obtain an MXene suspension.
[0054] (5) Centrifuge the suspension from step (4) for 25 minutes using a centrifuge (3500 r / min) and take the supernatant for later use.
[0055] (6) Place the product from step (5) in a freeze dryer for 48 hours to finally obtain the MXene product.
[0056] (7) Place the paraffin wax in a three-necked flask with a stirrer and heat it in a 90°C water bath for 30 minutes until it becomes completely liquid. Then cool it down to 60°C.
[0057] (8) During the stirring process, MXene flame retardant is slowly added to step (7) and stirred for 30 minutes until it is completely mixed and uniform to obtain flame retardant paraffin.
[0058] (9) At room temperature, place the traditional flame retardant APP in an empty beaker, then slowly add the product from step (8) multiple times, and continuously and vigorously stir the mixed solution to fully coat the APP particles with flame retardant paraffin. After cooling, the final product is obtained and named: APP@PW-MXene.
[0059] Example 2
[0060] This embodiment provides a multi-component phase change material flame retardant, which is PW and graphene oxide (GO) coated APP.
[0061] This embodiment also provides a method for preparing the above-mentioned multi-component phase change material flame retardant, the specific steps of which are as follows:
[0062] (1) Add 35 mL of concentrated sulfuric acid to a 500 mL beaker and place it in an ice-water bath until the temperature is approximately 0 °C.
[0063] (2) During continuous stirring, 1.5g of graphite powder and 0.75g of sodium nitrate are slowly added to step (1) in multiple steps. The system temperature must be kept below 4°C during this process.
[0064] (3) After stirring thoroughly, slowly add 4.5g of potassium peroxide to the product of step (2) in multiple steps. During this process, the system temperature must be kept between 0 and 5℃.
[0065] (4) Transfer the mixed solution from step (3) to a water bath, heat it to 35°C, and stir continuously for half an hour.
[0066] (5) Slowly add 69 mL of deionized water to the mixed solution from step (4) and adjust the temperature to 98 °C. React for 15 min.
[0067] (6) After the reaction is complete, cool the mixture in a water bath for 10 minutes, and then add 20 mL of 30% hydrogen peroxide solution and 420 mL of deionized water to the mixed solution in sequence.
[0068] (7) Cool to room temperature, centrifuge and wash multiple times until SO4 is reached. 2- Clean thoroughly and vacuum dry at 60℃ to obtain product GO.
[0069] (8) Place the paraffin wax in a three-necked flask with a stirring device, and heat it in a constant temperature water bath at 90°C for 30 minutes until it becomes completely liquid. Then cool it down to 60°C.
[0070] (9) During the stirring process, GO flame retardant is slowly added to step (8) and stirred for 30 minutes until it is completely mixed and uniform to obtain flame retardant paraffin.
[0071] (10) At room temperature, place the traditional flame retardant APP in an empty beaker, then slowly add the product from step (9) multiple times, and continuously stir the mixed solution to fully coat the APP particles with flame retardant paraffin. After cooling, the final product is obtained and named: APP@PW-GO.
[0072] Application Example 1
[0073] This application example provides an application of a multi-component phase change material flame-retardant rigid polyurethane (RPUF), which is an RPUF / 10% APP@PW-MXene composite material.
[0074] This application example also provides a method for preparing the above-mentioned RPUF, the specific steps of which are as follows:
[0075] (1) Weigh 50g of polyether polyol 950 and 50g of isocyanate 950 at room temperature for later use.
[0076] (2) Place the APP@PW-MXene (10g) from Example 1 into the polyether polyol 950 in step (1) and ultrasonically stir for 30 minutes until the mixture is uniform.
[0077] (3) Mix the product from step (2) with isocyanate 950 from step (1) in a mold, stir continuously, and foam for 30 seconds to obtain the final product, RPUF / 10%APP@PW-MXene composite material.
[0078] Application Example 2
[0079] This application example provides an application of a multi-component phase change material flame-retardant rigid polyurethane (RPUF), which is an RPUF / 10% APP@PW-GO composite material.
[0080] This application example also provides a method for preparing the above-mentioned RPUF, the specific steps of which are as follows:
[0081] (1) Weigh 50g of polyether polyol 950 and 50g of isocyanate 950 at room temperature for later use.
[0082] (2) Place the APP@PW-GO (10g) from Example 2 into the polyether polyol 950 in step (1) and ultrasonically stir for 30 minutes until the mixture is uniform.
[0083] (3) Mix the product from step (2) with isocyanate 950 from step (1) in a mold and stir continuously. After 30 seconds, foam to obtain the final product RPUF / 10%APP@PW-GO composite material.
[0084] Comparative Example 1
[0085] This comparative example provides an RPUF sample that is a pure RPUF without any flame retardant additives.
[0086] This comparative example also provides a method for preparing the above-mentioned pure RPUF sample, the specific steps of which are as follows:
[0087] (1) Weigh out 50g of polyether polyol 950 and 50g of isocyanate 950 for later use.
[0088] (2) Place the solution from step (1) into a mold and mix. Continue stirring until foaming begins in about 30 seconds to obtain a pure RPUF sample.
[0089] Comparative Example 2
[0090] This comparative example provides an RPUF / 15% APP@PW-MXene composite material. The preparation method of the RPUF / 15% APP@PW-MXene is roughly the same as that of Application Example 1, except that the amount of APP@PW-MXene added is changed from 10g to 15g.
[0091] Comparative Example 3
[0092] This comparative example provides an RPUF / 20% APP@PW-MXene composite material. The preparation method of the RPUF / 20% APP@PW-MXene is roughly the same as that of Application Example 1, except that the amount of APP@PW-MXene added is changed from 10g to 20g.
[0093] Comparative Example 4
[0094] This comparative example provides an RPUF / 15% APP@PW-GO composite material. The preparation method of the RPUF / 15% APP@PW-GO is roughly the same as that of Application Example 2, except that the amount of APP@PW-GO added is changed from 10g to 15g.
[0095] Comparative Example 5
[0096] This comparative example provides an RPUF / 20% APP@PW-GO composite material. The preparation method of the RPUF / 20% APP@PW-GO is roughly the same as that of Application Example 2, except that the amount of APP@PW-GO added is changed from 10g to 20g.
[0097] The results of oxygen index tests on the RPUF composite materials obtained in Application Examples 1-2 and Comparative Examples 1-5 are shown in Table 1.
[0098] Table 1
[0099]
[0100]
[0101] As can be seen from Table 1, compared with the pure RPUF sample without any flame retardant additives, the specific addition of the multi-component phase change material flame retardant set in this invention will greatly improve its LOI index, thereby greatly improving the flame retardant effect. The comparative example set in this invention is not a comparative example in the conventional sense, but a specific comparison with the embodiments of this invention. Other embodiments within the scope of this invention also show that within the addition range of this invention, the addition amount is relatively high, and the LOI index is also improved to a certain extent.
[0102] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A multi-component phase change material flame retardant, characterized in that, The multi-component phase change material flame retardant is a double-core-shell structure consisting of a core and a shell. The core is a traditional flame retardant, and the shell is a phase change material doped with nano flame retardant. After the nano flame retardant modifies the phase change material, it is physically coated on the outside of the traditional flame retardant to form a double-core-shell structure. The mass ratio of the phase change material, nano flame retardant and traditional flame retardant in the double core-shell structure is (1~5):(1~3):(1~20). The conventional flame retardant is one or more of aluminum hydroxide (ATH), ammonium polyphosphate (APP), dicyandiamide (DCD), expanded graphite (EG), melamine cyanurate (MCA), magnesium hydroxide (MDH), melamine (MEL), melamine polyphosphate (MPP), or pentaerythritol (PER). The nano flame retardant is one or more of MXene, graphene (GNS), graphene oxide (GO), or carbon nanotubes (CNT); the phase change material is paraffin wax.
2. A method for preparing a multi-component phase change material flame retardant, characterized in that, The multi-component phase change material flame retardant is the multi-component phase change material flame retardant according to claim 1; the preparation method includes the following steps: (1) Place the phase change material in a container with a stirring device, and then place it in a constant temperature water bath at 70~150℃ for 30~90 minutes until the phase change material becomes completely liquid. Then cool it down to 50~90℃, and then slowly add the nano flame retardant into the container while continuing to stir until it is completely mixed. (2) Place the traditional flame retardant particles in a container with a stirring device at a temperature of 10~30℃, and slowly add the mixed product obtained in step (1) to the container multiple times, while continuously and vigorously stirring the mixed solution so that the phase change material is fully wrapped around the outside of the traditional flame retardant particles.
3. The preparation method according to claim 2, characterized in that, The container mentioned in steps (1) and (2) is a three-necked flask.
4. The preparation method according to claim 2, characterized in that, The total stirring time in step (1) is 20~60 min.
5. The preparation method according to claim 2, characterized in that, The temperature conditions in step (2) are 10~25℃. Before the phase change material is completely solidified, it is continuously stirred with strong force. The strong stirring is carried out at a speed of 600~1200r / min.
6. The preparation method according to claim 2, characterized in that, The slow, multiple additions in step (2) specifically involve first adding 1-88% of the mixed product into the container within 5-30 minutes, and then adding the remaining mixed product into the container in 2-12 additions, with each addition taking 1-10 minutes.
7. The application of a multi-component phase change material flame retardant, characterized in that, The application is in polymer flame retardancy, and the multi-component phase change material flame retardant is the multi-component phase change material flame retardant of claim 1 or the multi-component phase change material flame retardant prepared by the preparation method of any one of claims 2 to 6.
8. The application according to claim 7, characterized in that, The polymer is one or more of epoxy resin, polyester or polyolefin materials, and the amount of the multi-component phase change material flame retardant added in the application of polymer flame retardancy is 1~20 wt.
9. The application according to claim 7, characterized in that, The polymer is rigid polyurethane (RPUF).