A rare earth hybrid flame retardant and its preparation method and application
Rare earth hybrid flame retardants are prepared by loading rare earth hydroxides through the in-situ deposition method, which solves the problems of flammability of polymer materials and low efficiency of traditional flame retardants, improves flame retardancy, smoke suppression and mechanical properties, and reduces production costs.
Patent Information
- Application Number
- CN202510867206.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-26
- Publication Date
- 2025-09-30
- Estimated Expiration
- 2045-06-26
AI Technical Summary
Existing polymer materials are flammable and produce large amounts of heat radiation and toxic smoke when burned. Traditional flame retardants have problems such as environmental toxicity, low flame retardant efficiency or significant impact on material properties, and the application cost of rare earth hydroxides is high.
Rare earth hydroxides are loaded on the surface of flame retardants by in-situ deposition method to construct rare earth hybrid flame retardant REH@FR. By regulating the ratio, synergistic flame retardancy is achieved in the condensed phase and gas phase, improving the flame retardancy and smoke suppression properties and simplifying the preparation process.
The flame retardancy, smoke suppression and mechanical properties of polymer materials have been simultaneously improved, production costs have been reduced, and the safety and comprehensive performance of materials in fire scenarios have been improved.
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Figure CN120365631B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical fields of inorganic synthesis, flame retardants and polymer materials, and in particular to a rare earth hybrid flame retardant and a preparation method and application thereof. Background Art
[0002] Polymer materials are widely used in fields such as construction, transportation, and electronics. However, common materials such as polyolefins, polystyrene, and polyurethane contain a large amount of elements such as C, H, O, and N in their molecular structures, with a limiting oxygen index (LOI) of only 17-20%. They are highly flammable and easily ignite when exposed to open flames or sustained high temperatures, generating a large amount of heat radiation and releasing toxic fumes, which not only cause material failure but can also easily cause fires.
[0003] Adding flame retardants is one of the most effective ways to create flame-retardant polymer materials. While halogen-based flame retardants can achieve high flame retardancy at low addition levels, they are being phased out due to their environmental toxicity. With sustainable development and growing global environmental awareness, flame retardants are increasingly being developed that are highly effective, halogen-free, non-toxic, environmentally friendly, and highly compatible with polymers. Halogen-free flame retardants are generally categorized as inorganic metal hydroxides, phosphorus-based, nitrogen-based, phosphorus-nitrogen-based, silicon-based, antimony-based, boron-based, and intumescent flame retardants. Inorganic metal hydroxide flame retardants, such as magnesium hydroxide and aluminum hydroxide, offer advantages such as non-toxicity, smoke suppression, widespread availability, excellent thermal stability, and environmental friendliness. However, their flame retardancy is low, requiring high filler loadings (>60 wt.%) to achieve a good flame retardant effect, which can negatively impact the mechanical and processing properties of polymer materials. Ammonium polyphosphate, a highly effective, non-toxic, and environmentally friendly inorganic phosphorus-based flame retardant, also suffers from high hygroscopicity and poor dispersibility, limiting its application in flame-retardant polymers. How to make full use of the inherent advantages of traditional flame retardants and study the efficient flame retardant modification technology of polymers has become a topic that has attracted much attention and needs to be solved urgently.
[0004] Rare earth metals, due to their advantages such as high reactivity, catalytic activity for esterification and dehydrogenation, thermal stability, and environmental friendliness, have driven the rapid development of rare earth-based flame retardants. These are often used in polymer flame retardancy in the form of rare earth oxides, rare earth ion-doped compounds, and rare earth metal complexes. Rare earth hydroxides, however, combine the flame retardant advantages of rare earth elements (catalytic carbonization) with those of inorganic hydroxides (cooling and dilution), but they have not been fully studied. However, the use of a single rare earth hydroxide as a flame retardant would significantly increase the cost of the flame retardant and polymer composite material.
[0005] Therefore, the present invention provides a rare earth hybrid flame retardant (REH@FR), which can achieve simultaneous improvement of the flame retardancy, smoke suppression and mechanical properties of polymer materials, and is of great significance to promoting technological progress in the field of flame retardant materials. Summary of the Invention
[0006] The purpose of the present invention is to provide a rare earth hybrid flame retardant and its preparation method and application, to obtain a rare earth hybrid flame retardant REH@FR for use in polymer materials, which exerts a flame retardant effect in both the gas phase and the condensed phase. By changing the proportion of the hybrid flame retardant, the influence of the rare earth hybrid flame retardant on the comprehensive properties of the polymer material, such as flame retardancy, smoke suppression, thermal stability, and mechanical properties, is regulated, thereby solving the problems raised in the background technology.
[0007] To achieve the above objectives, the present invention provides a method for preparing a rare earth hybrid flame retardant, wherein rare earth hydroxide is loaded on the surface of the flame retardant by an in-situ deposition method, and the specific steps are as follows:
[0008] S1. Add a rare earth compound to a solvent, stir and dissolve to obtain solution A, then add a flame retardant, and ultrasonically stir for 20-40 minutes to obtain suspension B;
[0009] S2. After heating the suspension B to 90° C., add 25.0-28.0% ammonia water dropwise until the pH value of the solution is 10-11 to obtain solution C;
[0010] S3. Solution C was stirred and reacted at 90°C for 12-24 hours. After the reaction was completed, the mixed solution was cooled to room temperature, the product was collected by centrifugation and washed thoroughly with deionized water and ethanol. The obtained product was dried in an oven at 80-100°C to constant weight to obtain the solid target product REH@FR.
[0011] Preferably, in step S1, the rare earth compound is one of rare earth nitrates and rare earth chlorides, wherein the rare earth element is one of scandium, yttrium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium.
[0012] Preferably, in step S1, the flame retardant is one or more of magnesium hydroxide, aluminum hydroxide, hydrotalcite, double hydroxide, basic magnesium carbonate, ammonium polyphosphate, piperazine pyrophosphate, melamine phosphate, melamine polyphosphate, melamine cyanurate, pentaerythritol, aluminum hypophosphite, aluminum phosphite, expandable graphite, zinc borate, graphene, transition metal disulfide, carbon nanotubes, halloysite, sepiolite, and kaolin.
[0013] Preferably, in step S1, the molar volume ratio of the rare earth compound to the solvent is (0.02-0.04 mol):1 L; wherein the solvent is a mixed solvent of water and ethanol, and the volume ratio of water to ethanol is 1:(0-3).
[0014] Preferably, the mass ratio of the rare earth hydroxide generated in step S2 to the flame retardant added in step S1 is 1:99-50:50.
[0015] The present invention also provides a rare earth hybrid flame retardant prepared by the above preparation method.
[0016] The present invention also provides the use of the rare earth hybrid flame retardant in preparing flame retardant polymer composite materials.
[0017] Preferably, the preparation method of the flame-retardant polymer composite material is: taking a polymer material, a rare earth hybrid flame retardant, a compatibilizer and a lubricant, premixing them and placing them in a torque rheometer, melt blending them at 120-180°C, and pressing them into a sheet at 130-200°C using a flat vulcanizer to prepare the flame-retardant polymer composite material.
[0018] Preferably, based on weight, it includes 30-100 parts of polymer material, 10-60 parts of rare earth hybrid flame retardant, 0-4 parts of compatibilizer and 0-1 part of lubricant.
[0019] Preferably, the polymer material is one of polyethylene, polypropylene, ethylene-vinyl acetate copolymer, thermoplastic elastomer, polyurethane, polystyrene, EPDM rubber, polyamide, polylactic acid, polycarbonate, epoxy resin, styrene-butadiene-styrene block copolymer, polyester, polyphenylene sulfide, polyphenylene oxide, polymethyl methacrylate, and natural rubber;
[0020] The lubricant is one or more of silicone powder, zinc stearate, paraffin wax, and PE wax;
[0021] The compatibilizer is one or more of maleic anhydride grafted polyethylene, maleic anhydride grafted polypropylene, maleic anhydride grafted ethylene-vinyl acetate copolymer, maleic anhydride grafted EPDM rubber, and maleic anhydride grafted hydrogenated styrene-butadiene-styrene block copolymer.
[0022] Therefore, the rare earth hybrid flame retardant and its preparation method and application provided by the present invention have the following beneficial effects:
[0023] (1) The present invention innovatively adopts the in-situ deposition method to successfully load rare earth hydroxides on the surface of the flame retardant, thereby constructing a REH@FR rare earth hybrid flame retardant, which realizes the condensed phase-gas phase dual-phase synergistic flame retardancy. In the condensed phase, the rare earth oxides obtained by the decomposition of the rare earth components can act as catalysts to promote the dehydrogenation and cross-linking reactions of the polymer, thereby forming a more continuous and dense carbon layer, effectively blocking the transfer of heat and combustible substances, which can significantly reduce the smoke density and improve the flame retardant performance. In the gas phase, the rare earth hydroxide can release water vapor when it is thermally decomposed, which can not only dilute the concentration of the combustible gas and slow down the rate of the combustion reaction, but also absorb the heat in the combustion zone, play a cooling role, and curb the intensification of the combustion. By adjusting the ratio of the rare earth hybrid flame retardant, the interaction between the rare earth hydroxide and the flame retardant is changed, and the flame retardant synergistic effect of the two in the condensed phase and gas phase is optimized, which has important practical significance for improving the safety of polymer materials in fire scenarios.
[0024] (2) The rare earth hybrid flame retardant proposed in this invention can directly control its own particle size distribution and surface morphology by adjusting the hybridization ratio, thereby improving its dispersibility in the polymer matrix. This characteristic helps to mitigate the adverse effects of flame retardant filling on the mechanical properties of polymer materials, thereby improving the overall performance of polymer materials. It promotes the widespread application of flame-retardant polymer composites in fields with high mechanical performance requirements, such as automobile manufacturing and architectural decoration.
[0025] (3) The preparation process of the rare earth hybrid flame retardant of the present invention is relatively simple. A one-step precipitation method is used to achieve hybridization of rare earth hydroxide and flame retardant. The entire process only needs to be carried out under normal pressure and low temperature conditions of 90°C. This method is simple to operate and easy to control, significantly reducing energy consumption and equipment costs during the production process. Moreover, the entire process is green and environmentally friendly, without the involvement of toxic solvents, which improves environmental performance.
[0026] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Figure 1 XRD patterns of hybrid flame retardants 1#-3# prepared in Examples 1-3 of the present invention;
[0028] Figure 2 Scanning electron microscope images of hybrid flame retardants 1#-3# prepared in Examples 1-3 of the present invention; wherein, a is MH; b is 3% LaH@MH (1#); c is 5% LaH@MH (2#); d is 10% LaH@MH (3#);
[0029] Figure 3 This is the XRD pattern of the 4# hybrid flame retardant prepared in Example 4 of the present invention;
[0030] Figure 4 This is a scanning electron microscope image of the 4# hybrid flame retardant prepared in Example 4 of the present invention; wherein a is MH; b is 5% NdH@MH (4#);
[0031] Figure 5 This is the XRD pattern of the 5# hybrid flame retardant prepared in Example 5 of the present invention;
[0032] Figure 6 This is a scanning electron microscope image of the 5# hybrid flame retardant prepared in Example 5 of the present invention; wherein a is ATH; b is 5% SmH@ATH (5#);
[0033] Figure 7 XRD patterns of hybrid flame retardants 6#-7# prepared in Examples 6-7 of the present invention;
[0034] Figure 8 These are scanning electron microscope images of hybrid flame retardants 6#-7# prepared in Examples 6-7 of the present invention; wherein, a is PAPP; b is 5%LaH@PAPP (6#); c is APP; and d is a scanning electron microscope image of 5%LaH@APP (7#). DETAILED DESCRIPTION
[0035] The technical solution of the present invention is further described below by means of the accompanying drawings and examples. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. Any other changes, modifications, substitutions, combinations, and simplifications made without violating the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the protection scope of the present invention. In addition, it should be understood that after reading the contents of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application and belong to the scope of protection of the present invention.
[0036] References to "embodiments" herein mean that the specific features, structures, or characteristics described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the word "embodiment" in various places in the specification does not necessarily refer to the same embodiment, nor does it particularly limit its independence or relevance to other embodiments. In principle, in this application, as long as there are no technical contradictions or conflicts, the various technical features mentioned in the embodiments can be combined in any manner to form a corresponding implementable technical solution.
[0037] Unless otherwise defined, the technical terms used herein have the same meanings as those generally understood by those skilled in the art to which this application belongs; the use of relevant terms herein is only for describing specific embodiments and is not intended to limit this application.
[0038] Unless otherwise specified in the present invention, the reagents, instruments, equipment and performance testing methods used are those commonly used by those skilled in the art.
[0039] Example 1
[0040] This embodiment provides a method for preparing a rare earth hybrid flame retardant, which specifically includes the following steps:
[0041] (1) Add 28 mmol (10.40 g) of lanthanum chloride heptahydrate to 700 ml of deionized water and stir to dissolve to obtain solution A. Then add 171.9 g of magnesium hydroxide (so that the mass ratio of lanthanum hydroxide to magnesium hydroxide (MH) is 3:97) and stir ultrasonically for 30 min to obtain suspension B.
[0042] (2) After heating the suspension B to 90°C, add 25.0-28.0% ammonia water dropwise until the pH value of the solution reaches 11 to obtain solution C.
[0043] (3) Solution C was stirred at 90°C for 24 h. After the reaction, the mixture was cooled to room temperature, the precipitate was collected by centrifugation, and then washed thoroughly with deionized water and ethanol. Finally, the resulting product was placed in an oven and dried at 80°C to constant weight to obtain hybrid flame retardant No. 1, which was recorded as 3%LaH@MH.
[0044] Example 2
[0045] This example provides a method for preparing a rare earth hybrid flame retardant. The only difference from Example 1 is that in this example, 101.03 g of magnesium hydroxide is added to solution A (so that the mass ratio of lanthanum hydroxide to magnesium hydroxide is 5:95), ultimately obtaining hybrid flame retardant 2#, which is recorded as 5%LaH@MH.
[0046] Example 3
[0047] This example provides a method for preparing a rare earth hybrid flame retardant. The only difference from Example 1 is that in this example, 47.85 g of magnesium hydroxide is added to solution A (so that the mass ratio of lanthanum hydroxide to magnesium hydroxide is 10:90), ultimately obtaining hybrid flame retardant #3, which is recorded as 10%LaH@MH.
[0048] Depend on Figure 1 X-ray diffraction (XRD) pattern analysis shows that the diffraction peaks of hybrid flame retardants 1#-3# all contain characteristic diffraction peaks of La(OH)3 (JCPDS no.36-1481) and Mg(OH)2 (JCPDS no. 86-0441), indicating that hybrid flame retardants 1#-3# all contain the above two substances. Figure 2This is the scanning electron microscope image of 1#-3# hybrid flame retardant. It can be seen from the figure that pure magnesium hydroxide is a relatively smooth sheet, while nanoparticles appear on the surface of the sheet of 1#-3# hybrid flame retardant. As the loading amount of lanthanum hydroxide increases, the size of the nanoparticles increases and the number increases, indicating that lanthanum hydroxide is successfully loaded on the surface of magnesium hydroxide to prepare 1#-3# hybrid flame retardant.
[0049] Example 4
[0050] This example provides a method for preparing a rare earth hybrid flame retardant. The only difference from Example 1 is that in this example, 28 mmol (10.04 g) of neodymium chloride hexahydrate is added to 700 ml of deionized water and stirred to dissolve, obtaining solution A. 103.87 g of magnesium hydroxide is then added (so that the mass ratio of neodymium hydroxide to magnesium hydroxide is 5:95), ultimately obtaining hybrid flame retardant #4, designated as 5%NdH@MH.
[0051] Depend on Figure 3 From the XRD pattern analysis, it can be seen that the diffraction peaks of 4# hybrid flame retardant include the characteristic diffraction peaks of Nd(OH)3 (JCPDS no.70-0214) and Mg(OH)2 (JCPDS no. 86-0441), indicating that 4# hybrid flame retardant contains both of the above substances. Figure 4 This is a scanning electron microscope image of the 4# hybrid flame retardant. It can be seen from the figure that pure magnesium hydroxide is a relatively smooth sheet, while the sheet surface of the 4# hybrid flame retardant has more nanoparticles, indicating that neodymium hydroxide is successfully loaded onto the surface of magnesium hydroxide to prepare the 4# hybrid flame retardant.
[0052] Example 5
[0053] This example provides a method for preparing a rare earth hybrid flame retardant. The only difference from Example 1 is that in this example, 28 mmol (10.22 g) of samarium chloride heptahydrate is added to 700 ml of deionized water and stirred to dissolve to obtain solution A. Then, 134.27 g of aluminum hydroxide is added (so that the mass ratio of samarium hydroxide to aluminum hydroxide is 5:95), ultimately obtaining hybrid flame retardant 5#, which is recorded as 5%SmH@ATH.
[0054] Depend on Figure 5 From the XRD pattern analysis, it can be seen that the diffraction peaks of 5# hybrid flame retardant include the characteristic diffraction peaks of Sm(OH)3 (JCPDS no. 83-2036) and Al(OH)3 (JCPDS no. 33-0018), indicating that 5# hybrid flame retardant contains both of the above substances. Figure 6This is a scanning electron microscope image of the 5# hybrid flame retardant. It can be seen from the figure that pure aluminum hydroxide is a sheet with a relatively smooth surface, while the sheet surface of the 5# hybrid flame retardant has more nanoparticles, indicating that samarium hydroxide is successfully loaded onto the surface of aluminum hydroxide to prepare the 5# hybrid flame retardant.
[0055] Example 6
[0056] This embodiment provides a method for preparing a rare earth hybrid flame retardant, which specifically includes the following steps:
[0057] (1) To a total volume of 800 ml of ethanol-water (volume ratio 3:1) mixed solvent, 16 mmol (6.93 g) of lanthanum nitrate hexahydrate was added and stirred to dissolve to obtain solution A. Then, 57.73 g of piperazine pyrophosphate (PAPP) was added (so that the mass ratio of lanthanum hydroxide to piperazine pyrophosphate (PAPP) was 5:95) and ultrasonically stirred for 30 min to obtain suspension B.
[0058] (2) After heating the suspension B to 90°C, add 25.0-28.0% ammonia water dropwise until the pH value of the solution is about 10 to obtain solution C;
[0059] (3) Solution C was stirred at 90°C for 12 h. After the reaction, the mixture was cooled to room temperature, the precipitate was collected by centrifugation, and then washed thoroughly with ethanol. Finally, the resulting product was placed in an oven and dried at 80°C to constant weight to obtain hybrid flame retardant 6#, which was recorded as 5%LaH@PAPP.
[0060] Example 7
[0061] This example provides a method for preparing a rare earth hybrid flame retardant. The only difference from Example 6 is that in this example, 57.73 g of ammonium polyphosphate (APP) is added to solution A (so that the mass ratio of lanthanum hydroxide to ammonium polyphosphate (APP) is 5:95), ultimately obtaining hybrid flame retardant 7#, which is recorded as 5%LaH@APP.
[0062] Depend on Figure 7 From the XRD pattern analysis, it can be seen that the diffraction peaks of 6#-7# hybrid flame retardant include the characteristic diffraction peaks of La(OH)3 (JCPDS no.36-1481) and the corresponding original flame retardant PAPP or APP, indicating that 6#-7# hybrid flame retardant contains both of the above substances. Figure 8 This is a scanning electron microscope image of the 6-7# hybrid flame retardant. It can be seen from the figure that both PAPP and APP are blocks with relatively smooth surfaces, while after loading lanthanum hydroxide, the surface of the corresponding 6#-7# hybrid flame retardant becomes rough and has more nanoparticles distributed, indicating that lanthanum hydroxide is successfully loaded onto the surface of PAPP and APP to prepare the 6#-7# hybrid flame retardant.
[0063] To verify the performance of the rare earth hybrid flame retardant REH@FR prepared in the above examples, it was added to polymer materials to explore changes in their flame retardancy, smoke suppression, and mechanical properties. The following application examples illustrate methods for preparing flame-retardant polymer composites using rare earth hybrid flame retardants.
[0064] Application Example 1
[0065] Weigh 36 parts EVA, 60 parts 1# hybrid flame retardant (3% LaH@MH), 4 parts maleic anhydride-grafted ethylene-vinyl acetate copolymer (compatibility agent), and 0.3 parts silicone powder (lubricant) in the appropriate proportions. These components were premixed in the aforementioned proportions and placed in a torque rheometer for melt blending at 130°C. The mixture was then pressed into sheets on a flat-plate vulcanizer at 160°C to prepare a flame-retardant polymer composite.
[0066] Application Example 2
[0067] The difference from Application Example 1 is that Application Example 2 uses 2# hybrid flame retardant (5% LaH@MH).
[0068] Application Example 3
[0069] The difference from Application Example 1 is that Application Example 3 uses 3# hybrid flame retardant (10% LaH@MH).
[0070] Application Example 4
[0071] The difference from Application Example 1 is that Application Example 4 uses 4# hybrid flame retardant (5% NdH@MH).
[0072] Application Example 5
[0073] The difference from Application Example 1 is that Application Example 5 uses 5# hybrid flame retardant (5% SmH@ATH).
[0074] To further verify the performance of 1-5# rare earth hybrid flame retardants, pure resin (Comparative Example 1), unmodified magnesium hydroxide (Comparative Example 2), and aluminum hydroxide (Comparative Example 3) were used in equal amounts to replace the rare earth hybrid flame retardants in EVA flame retardancy. Comparative formulations, as shown in Table 1, were designed and subjected to limiting oxygen index, vertical combustion, cone calorimetry, smoke density, and mechanical property tests. Table 1 lists the formulations and key performance parameters of the flame-retardant EVA composites.
[0075] Table 1 Flame retardant EVA composite material formula and main performance parameters
[0076] ;
[0077] In the table, LOI: Limiting Oxygen Index; UL-94: Vertical Burning Flame Retardant Rating; pHRR: Peak Heat Release Rate; THR: Total Heat Release; pCOPR: Peak CO Release Rate; PCO2PR: Peak CO2 Release Rate; Ds-max: Maximum Smoke Density.
[0078] Application Example 6
[0079] Weigh 68 parts of thermoplastic elastomer (TPE) and 32 parts of hybrid flame retardant #6 (5% LaH@PAPP) in the appropriate proportions. Premix the components in the above proportions and place them in a torque rheometer for melt blending at 180°C. The mixture is then pressed into sheets on a flat-plate vulcanizer at 195°C to prepare a flame-retardant polymer composite.
[0080] To further validate the performance of hybrid flame retardant 6# (5% LaH@PAPP), it was used in flame-retardant TPE with equal amounts of pure resin (Comparative Example 4) and unmodified PAPP (Comparative Example 5). Comparative formulations, as shown in Table 2, were designed and tested for limiting oxygen index, vertical combustion, cone calorimetry, smoke density, and mechanical properties. Table 2 lists the formulations and key performance parameters of the flame-retardant TPE composites.
[0081] Table 2 Flame retardant TPE composite material formula and main performance parameters
[0082] ;
[0083] In the table, LOI: Limiting Oxygen Index; UL-94: Vertical Burning Flame Retardant Rating; pHRR: Peak Heat Release Rate; THR: Total Heat Release; pCOPR: Peak CO Release Rate; PCO2PR: Peak CO2 Release Rate; Ds-max: Maximum Smoke Density.
[0084] Application Example 7
[0085] Weigh 93.5 parts polyurethane (TPU) and 6.5 parts 7# hybrid flame retardant (5% LaH@APP) in the appropriate proportions. Premix the components in these proportions, melt-blend and pelletize them using a twin-screw extruder at 180°C. Then, press them into sheets using an injection molding machine at 195°C to prepare a flame-retardant polymer composite.
[0086] To further validate the performance of hybrid flame retardant 7# (5% LaH@APP), it was used in flame-retardant TPU composites in equal amounts, replacing pure resin (Comparative Example 6) and unmodified APP (Comparative Example 7). Comparative formulations, as shown in Table 3, were designed and tested for limiting oxygen index, vertical combustion, cone calorimetry, smoke density, and mechanical properties. Table 3 lists the formulations and key performance parameters of the flame-retardant TPU composites.
[0087] Table 3 Flame retardant TPU composite material formula and main performance parameters
[0088] ;
[0089] In the table, LOI: Limiting Oxygen Index; UL-94: Vertical Burning Flame Retardant Rating; pHRR: Peak Heat Release Rate; THR: Total Heat Release; pCOPR: Peak CO Release Rate; PCO2PR: Peak CO2 Release Rate; Ds-max: Maximum Smoke Density.
[0090] Based on the above experimental results, the following conclusions are drawn:
[0091] (1) The prepared 1-7# rare earth hybrid flame retardants can enable polymer composite materials to pass the UL-94 V-0 level, and the limiting oxygen index is higher than that of pure polymers and polymer composite materials filled with unmodified flame retardants, indicating that they have significant advantages in inhibiting the combustion of polymer materials and improving the fire safety of materials.
[0092] (2) The flame retardant polymer composites prepared by rare earth hybrid flame retardants have lower thermal and non-thermal hazards than pure polymers and polymer composites filled with unmodified flame retardants, indicating that rare earth hybrid flame retardants have both good flame retardant and smoke suppression properties.
[0093] (3) The compatibility of rare earth hybrid flame retardants with polymer substrates is improved, so the tensile strength and elongation at break of the prepared flame retardant polymer composite materials are better than those of the polymer composite materials filled with unmodified flame retardants, which effectively alleviates the negative impact of flame retardant filling on the mechanics and comprehensive properties of the polymer matrix.
[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.
Claims
1. A method for preparing a rare earth hybrid flame retardant, characterized in that: The rare earth hydroxide is loaded on the surface of the flame retardant by in-situ deposition method. The specific steps are as follows: S1. Add a rare earth compound to a solvent, stir and dissolve to obtain solution A, then add a flame retardant, and ultrasonically stir for 20-40 minutes to obtain suspension B; S2. After heating the suspension B to 90° C., add 25.0-28.0% ammonia water dropwise until the pH value of the solution is 10-11 to obtain solution C; S3. Solution C is stirred and reacted at 90°C for 12-24 hours. After the reaction is completed, the mixed solution is cooled to room temperature, the product is collected by centrifugation, and thoroughly washed with deionized water and ethanol. The resulting product is dried in an oven at 80-100°C to constant weight to obtain a solid target product REH@FR with rare earth hydroxide nanoparticles loaded on the surface; In step S1, the rare earth compound is one of rare earth nitrates and rare earth chlorides, wherein the rare earth element is one of scandium, yttrium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium; and the flame retardant is one of magnesium hydroxide, aluminum hydroxide, hydrotalcite, double hydroxide, basic magnesium carbonate, ammonium polyphosphate, piperazine pyrophosphate, melamine phosphate, melamine polyphosphate, melamine cyanurate, aluminum hypophosphite, aluminum phosphite, and expandable graphite; The mass ratio of the rare earth hydroxide generated in step S2 to the flame retardant added in step S1 is 1:99-50:
50.
2. The method for preparing a rare earth hybrid flame retardant according to claim 1, wherein: In step S1, the molar volume ratio of the rare earth compound to the solvent is (0.02-0.04 mol):1 L; wherein the solvent is a mixed solvent of water and ethanol, and the volume ratio of water to ethanol is 1:(0-3).
3. A rare earth hybrid flame retardant, characterized in that: The rare earth hybrid flame retardant is prepared by the preparation method according to any one of claims 1-2.
4. The use of a rare earth hybrid flame retardant according to claim 3, characterized in that: The rare earth hybrid flame retardant is used in the preparation of flame retardant polymer composite materials.
5. The use of a rare earth hybrid flame retardant according to claim 4, characterized in that: The flame-retardant polymer composite material is prepared by premixing a polymer material, a rare earth hybrid flame retardant, a compatibilizer, and a lubricant, placing the mixture in a torque rheometer, performing melt blending at 120-180° C., and pressing the mixture into a sheet at 130-200° C. using a flat vulcanizer to prepare the flame-retardant polymer composite material.
6. The use of a rare earth hybrid flame retardant according to claim 5, characterized in that: Calculated by weight, it includes 30-100 parts of polymer material, 10-60 parts of rare earth hybrid flame retardant, 0-4 parts of compatibilizer and 0-1 part of lubricant.
7. The use of a rare earth hybrid flame retardant according to claim 5, characterized in that: The polymer material is one of polyethylene, polypropylene, ethylene-vinyl acetate copolymer, polyurethane, polystyrene, EPDM rubber, polyamide, polylactic acid, polycarbonate, epoxy resin, styrene-butadiene-styrene block copolymer, polyester, polyphenylene sulfide, polyphenylene oxide, polymethyl methacrylate, and natural rubber; The lubricant is one or more of silicone powder, zinc stearate, paraffin wax, and PE wax; The compatibilizer is one or more of maleic anhydride grafted polyethylene, maleic anhydride grafted polypropylene, maleic anhydride grafted ethylene-vinyl acetate copolymer, maleic anhydride grafted EPDM rubber, and maleic anhydride grafted hydrogenated styrene-butadiene-styrene block copolymer.