A carbon-based stannate material, a method for preparing the same, and a polymer

Abstract

This invention discloses a carbon-based stannate material, its preparation method, and a polymer. The carbon-based stannate material comprises carbon-based stannate particles, which include stannate and carbon dopant elements, and the carbon-based stannate particles are flocculent. The unique flocculent structure of the carbon-based stannate particles increases their specific surface area, and the flocculent structure can penetrate the molecular structure of polymers, improving its compatibility with organic polymers. Simultaneously, carbon atoms readily form covalent bonds with oxygen and nitrogen atoms in the functional groups of organic polymers, further improving compatibility with organic polymers, thereby enhancing the compatibility performance of the carbon-based stannate material in various polymer applications.

Description

Technical Field

[0001] This invention relates to the field of inorganic non-metallic functional filler technology, and more specifically, to a carbon-based stannate material, its preparation method, and polymer. Background Technology

[0002] Stannates are used as flame retardants and have good flame retardant properties. They are often incorporated into polymer substrates to form polymer materials with flame retardant properties.

[0003] In the prior art, stannates are usually spherical particles. When inorganic stannates are doped into polymer substrates, there is a problem of poor inorganic-organic interface compatibility, which affects the surface morphology and mechanical properties of the polymer.

[0004] To overcome the problem of poor inorganic-organic compatibility, existing technologies typically employ two solutions. One is to improve dispersibility and compatibility through nano-sizing. However, nano-sizing easily leads to particle agglomeration, increasing the difficulty of dispersing inorganic flame retardants in polymers. Nano-sizing also carries risks such as increased cost, processing challenges, and potential health hazards. The other approach involves surface modification using coupling agents to treat inorganic flame retardants, thereby improving their compatibility with organic polymers. However, this method increases process complexity and cost. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned defects in the prior art and provide a carbon-based stannate material, its preparation method and polymer, which can improve compatibility with organic polymers.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: On one hand, the present invention provides a carbon-based stannate material, characterized in that it comprises carbon-based stannate particles, wherein the carbon-based stannate particles include stannate and carbon doping elements, and the carbon-based stannate particles are flocculent.

[0007] Optionally, the stannate includes one or more of zinc stannate, strontium stannate, and magnesium stannate.

[0008] Optionally, the average particle size of the carbon-based stannate particles is 1 μm to 50 μm.

[0009] Optionally, the stannate has a perovskite crystal structure.

[0010] Optionally, the carbon doping element accounts for 5% to 10% of the atomic weight of the carbon-based stannate particles.

[0011] In another aspect, the present invention provides a method for preparing the above-mentioned carbon-based stannate material, comprising the following steps: A soluble metal salt and a soluble stannate are mixed and added to a solvent to obtain a reaction solution; A flocculent biomass template is added to the reaction solution to carry out a chemical reaction, in which the soluble metal salt and the soluble stannate react to generate an inorganic compound of metal-stannate. The inorganic compound is loaded on the flocculent biomass template to obtain a complex of inorganic compound-biomass template loaded with metal-stannate. The composite is calcined to carbonize the flocculent biomass template, thereby obtaining the carbon-based stannate material.

[0012] Optionally, the calcination temperature is 600℃~700℃; the mass ratio of the flocculent biomass template to the inorganic compound of the metal-stannate is 1:30~1:20; the flocculent biomass template includes one or more of reed flowers, willow catkins, and corn ears.

[0013] In another aspect, the present invention provides a polymer comprising a polymer matrix material and a carbon-based stannate material doped in the polymer matrix material, wherein the carbon-based stannate material is the aforementioned carbon-based stannate material or is prepared by the aforementioned preparation method.

[0014] Optionally, the amount of the carbon-based stannate particles added is 3wt% to 5wt%.

[0015] Optionally, the polymer matrix material is rubber or resin.

[0016] Implementing the embodiments of the present invention will have the following beneficial effects: The carbon-based stannate material disclosed in this invention comprises carbon-based stannate particles, which include stannate and carbon dopant elements, and the carbon-based stannate particles are flocculent. The unique flocculent structure of the carbon-based stannate particles not only increases their specific surface area, but also allows them to penetrate the molecular structure of polymers, improving their compatibility with organic polymers. Furthermore, the carbon atoms readily form covalent bonds with oxygen and nitrogen atoms in the functional groups of organic polymers, further improving compatibility with organic polymers, thereby enhancing the compatibility performance of the carbon-based stannate material in various polymer applications. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] in: Figure 1 This is an electron microscope image of carbon-based strontium stannate particles provided in an embodiment of the present invention.

[0019] Figure 2 yes Figure 1 Magnified electron microscope image.

[0020] Figure 3 This is an XRD pattern of carbon-based strontium stannate particles provided in an embodiment of the present invention.

[0021] Figure 4 This is the energy spectrum of the carbon-based strontium stannate particles provided in the embodiments of the present invention.

[0022] Figure 5 This is an infrared image of carbon-based strontium stannate particles provided in an embodiment of the present invention.

[0023] Figure 6 This is a thermogravimetric curve of the EP material before and after adding flocculent carbon-based strontium stannate, provided in an embodiment of the present invention.

[0024] Figure 7 This is a thermogravimetric curve of the PVC material before and after adding flocculent carbon-based strontium stannate, provided in an embodiment of the present invention. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and 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.

[0026] This invention discloses a carbon-based stannate material, comprising carbon-based stannate particles, wherein the carbon-based stannate particles include stannate and carbon doping elements, and the carbon-based stannate particles are flocculent.

[0027] It should be noted that in the embodiments of the present invention, the carbon-based stannate particles are flocculent. Flocculent structure is a biomimetic structure, such as the flocculent structure of reed flowers, willow catkins, and corn ears. The flocculent structure of carbon-based stannate particles not only increases the specific surface area of ​​the particles, but also allows the flocculent structure to penetrate the molecular structure of polymers, thereby enhancing compatibility with organic molecules. At the same time, carbon atoms can facilitate covalent bonding with oxygen, nitrogen, and other atoms in the functional groups of organic molecules, which can also enhance the compatibility between inorganic particles and organic molecules, thereby improving the compatibility performance of carbon-based stannate materials in various polymer applications.

[0028] In some alternative embodiments, the stannate includes one or more of zinc stannate, strontium stannate, and magnesium stannate.

[0029] It should be noted that the carbon-based stannate materials of this invention are mainly used as functional fillers for organic polymers, improving compatibility with organic polymers through their flocculent structure and doped carbon atoms. As flame-retardant fillers, carbon-based stannate materials include flocculent zinc carbon-based stannate, strontium carbon-based stannate, and magnesium carbon-based stannate. As insulating fillers, carbon-based stannate materials include zinc carbon-based stannate and strontium carbon-based stannate.

[0030] Furthermore, stannates have a perovskite crystal structure. This perovskite crystal structure provides a stable, tunable, and multifunctional framework for carbon-based stannates, enabling them to function reliably.

[0031] In some optional embodiments, the average particle size of the carbon-based stannate particles is 1 μm to 50 μm, preferably 1 μm to 20 μm. The carbon-based stannate particles have both sufficient specific surface area and ensure good dispersibility.

[0032] Furthermore, the particle size of carbon-based stannates can also be in the nanometer range.

[0033] In some optional embodiments, the carbon doping element accounts for 5% to 10% of the atomic weight of the carbon-based stannate particles.

[0034] Too little or too much carbon doping will prevent carbon-based stannate particles from forming a flocculent morphology. In this embodiment, the carbon doping element accounts for 5% to 10% of the atomic weight of the carbon-based stannate particles, resulting in pure-phase carbon-based stannate particles that can form a flocculent morphology.

[0035] The method for preparing the carbon-based stannate material according to any of the above embodiments includes the following steps: (1) Mix the soluble metal salt and the soluble stannate and add them to the solvent to obtain the reaction solution.

[0036] (2) Add flocculent biomass template to the reaction solution and carry out a chemical reaction to generate an inorganic compound of metal-stannate by reacting soluble metal salt and soluble stannate. The inorganic compound is loaded on the biomass template to obtain a complex of inorganic compound of metal-stannate and biomass template.

[0037] (3) The composite is calcined to carbonize the biomass template and obtain carbon-based stannate material.

[0038] It should be noted that the chemical reaction in step (2) can be a co-precipitation reaction, a sol-gel reaction, or a hydrothermal reaction. Step (2) can be a one-step reaction, or a two-step or multi-step reaction. Specifically, it can be that an inorganic compound of metal-stannate is first generated, and then the reaction solution containing the inorganic compound of metal-stannate and the biomass template are placed in a closed reaction vessel for hydrothermal reaction. Alternatively, it can be that the soluble metal salt, soluble stannate, solvent, and biomass template are first mixed evenly, and then a precipitation reaction or hydrothermal reaction is carried out to generate a complex of inorganic compound of metal-stannate and biomass template. Alternatively, it can be that the soluble metal salt, soluble stannate, and solvent are first mixed evenly, and then the biomass template is added for precipitation reaction or hydrothermal reaction. The above specific embodiments are merely examples and are not intended to limit the scope of protection to the above methods. Any method that conforms to the inventive principle of this invention and falls within the scope of protection of this invention if the preparation sequence can be reasonably adjusted by those skilled in the art.

[0039] It is understood that the embodiments of the present invention utilize flocculent biomass templates to achieve the loading of metal-stannates. The flocculent biomass templates have a unique flocculent structure, which effectively controls the microstructure and morphology of carbon-based stannate particles, thus obtaining flocculent carbon-based stannate particles. This increases the specific surface area of ​​the carbon-based stannate particles. Moreover, the flocculent structure can penetrate the molecular structure of polymers, which can enhance the compatibility with organic molecules. Furthermore, the carbon atoms after biomass carbonization can facilitate covalent bonding with oxygen, nitrogen, and other atoms in the functional groups of organic molecules, which can also enhance the compatibility between inorganic particles and organic molecules, thereby improving the compatibility performance of carbon-based stannate materials in various polymer applications.

[0040] Further, in step (2), the reaction yields a suspension of inorganic compound-biomass template complex containing metal-stannate. The suspension is filtered to obtain a precipitate of inorganic compound-biomass template complex containing metal-stannate. Soluble impurities on its surface and inside are washed to avoid a decrease in the purity of the product after calcination. After drying, it is calcined. After calcination, it is crushed into particles to obtain carbon-based stannate particles.

[0041] In some optional embodiments, the average particle size of the carbon-based stannate particles is 1 μm to 50 μm, preferably 1 μm to 20 μm, and the average particle size of the flocculent biomass template used is 100 μm to 1 cm. Furthermore, the carbon-based stannate particle size can also be in the nanoscale.

[0042] In this embodiment, the size of the carbon-based stannate particles is controlled by controlling the size of the biomass template particles. The flocculent structure of the biomass template can prevent the aggregation of nanoparticles, thereby generating nanoscale products without aggregation.

[0043] Furthermore, the mass ratio of the flocculent biomass template to the inorganic compound of metal-stannate is 1:30 to 1:20; the atomic percentage of carbon dopant in carbon-based stannate particles is 5% to 10%.

[0044] It is understandable that the atomic percentage of carbon dopant in carbon-based stannate particles can be controlled by controlling the mass ratio of flocculent biomass template to inorganic compounds of metal-stannate. This allows carbon doping to provide support for maintaining the flocculent morphology, while carbon doping adds new reaction sites to stannate, which can enhance the covalent bonding with organic polymers.

[0045] In some alternative embodiments, the soluble metal salt includes a soluble strontium salt, a soluble zinc salt, or a soluble magnesium salt.

[0046] Optionally, soluble strontium salts include strontium chloride and / or strontium nitrate, soluble zinc salts include zinc chloride and / or zinc nitrate, soluble magnesium salts include one or more of magnesium chloride, magnesium sulfate, and magnesium nitrate, and soluble stannates include sodium stannate and / or potassium stannate.

[0047] It should be noted that strontium chloride can completely ionize into strontium ions (Sr²⁺) in solution. + Strontium nitrate has high solubility and reacts rapidly with stannate ions; strontium nitrate also ionizes into strontium ions in solution, and nitrate ions are relatively stable during the reaction, making it less likely to introduce impurities. Similarly, zinc chloride and zinc nitrate can provide zinc ions (Zn²⁺). + Magnesium chloride, magnesium sulfate, and magnesium nitrate can provide magnesium ions (Mg²⁺). + Sodium stannate (Na₂SnO₃) exists in aqueous solution as stannate ions (SnO₃²⁻). - It exists in the form of ) and can be combined with Sr² + / Zn² + A coprecipitation reaction occurs; similarly, potassium stannate (K2SnO3) can provide SnO3²⁻. - These combinations of strontium salts / zinc salts / magnesium salts and stannates can fully ionize in the solvent to produce the required ions, providing sufficient reactants for the coprecipitation reaction, ensuring the smooth progress of the reaction, and generating strontium stannate / zinc stannate / magnesium stannate precursors.

[0048] In one specific embodiment, strontium chloride is added to a sodium stannate solution to obtain a reaction solution; a flocculent biomass template is added to the reaction solution to carry out a co-precipitation reaction, whereby strontium chloride and sodium stannate react to generate strontium stannate, which is then loaded onto the biomass template to obtain a strontium stannate-biomass template composite; the composite is then calcined to carbonize the biomass template to obtain a carbon-based strontium stannate material.

[0049] In another specific embodiment, zinc chloride is added to a sodium stannate solution to obtain a reaction solution; a flocculent biomass template is added to the reaction solution to carry out a co-precipitation reaction, where zinc chloride and sodium stannate react to generate zinc stannate, which is then loaded onto the biomass template to obtain a zinc stannate-biomass template composite; the composite is then calcined to carbonize the biomass template to obtain a carbon-based zinc stannate material.

[0050] In another specific embodiment, magnesium chloride is added to a sodium stannate solution to obtain a reaction solution; a flocculent biomass template is added to the reaction solution to carry out a co-precipitation reaction, where magnesium chloride and sodium stannate react to generate magnesium stannate, which is then loaded onto the biomass template to obtain a magnesium stannate-biomass template composite; the composite is then calcined to carbonize the biomass template to obtain a carbon-based magnesium stannate material.

[0051] Furthermore, after adding flocculent biomass templates to the reaction solution, the pH of the reaction solution is adjusted to 10-12, and then treated with ultrasound or in a reaction vessel before being allowed to stand for reaction.

[0052] For example, soluble stannates dissociate into SnO3 in solution. 2- However, this ion is easily hydrolyzed under neutral or acidic conditions to form the Sn(OH)4 precursor; a strongly alkaline environment (pH 10~12) can inhibit SnO3. 2- Hydrolysis ensures its stable existence in solution, guaranteeing its separation from soluble strontium salts and the release of Sr. 2+ A directional reaction occurs: Sr 2+ +SnO3 2- →SrSnO3↓ (Strontium stannate). The purpose of ultrasound or a reaction vessel is to prevent uneven mixing and incomplete reaction of the solution system.

[0053] Furthermore, the calcination temperature is 600℃~700℃.

[0054] It should be noted that the calcination temperature is controlled between 600℃ and 700℃ to ensure complete carbonization of the biomass template, while avoiding excessive crystal growth and sintering of the carbon-based stannate particles, which could alter their structure. Carbon-based stannate materials formed at 600℃ to 700℃ have ideal carbon content and carbon oxidation structure distribution, which is beneficial for the formation of a rich porous structure and high specific surface area.

[0055] In some alternative embodiments, the biomass template includes one or more of reed flowers, willow catkins, and corn ears.

[0056] Reed flowers, willow catkins, and corn ears are all natural biomasses with a high specific surface area microstructure. Moreover, these materials are agricultural or natural waste, which reduces production costs and makes the process environmentally friendly.

[0057] Furthermore, the amount of biomass template added to the reaction solution is 1 g / L to 10 g / L, and the amount of biomass template added can be adjusted adaptively according to the solute and its content in the reaction solution.

[0058] In one specific embodiment, the method for preparing the flocculent biomass template includes the following steps: Naturally formed flocculent biomass, such as reed flowers, willow catkins, or corn cobs, is collected, washed, dried, and crushed in sequence to obtain granular flocculent biomass templates.

[0059] The particle size of the flocculent biomass template can be in the nanometer, micrometer, or millimeter range. The particle size of the flocculent inorganic particles obtained after calcination can be controlled by adjusting the particle size of the biomass template, the impregnation temperature and time of the biomass template in the reaction solution, and the calcination temperature and time.

[0060] This invention also discloses a polymer comprising a polymer matrix material and a carbon-based stannate material doped in the polymer matrix material. The carbon-based stannate material includes the carbon-based stannate material described in any of the above embodiments or is prepared by the preparation method described in any of the above embodiments.

[0061] Furthermore, the polymer matrix material can be classified as either plastic resin or rubber. Specifically, plastic resins can include one or more of the following: polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), polyurethane (PU), polycarbonate (PC), polyamide (PA), polyethylene terephthalate (PET), acrylonitrile-butadiene-styrene copolymer (ABS), and epoxy resin (EP). Rubber materials can include one or more of the following: natural rubber, styrene-butadiene rubber, ethylene propylene rubber, nitrile rubber, and ethylene propylene diene monomer (EPDM).

[0062] In this embodiment, by adding carbon-based stannate particles, the high specific surface area structure of the carbon-based stannate particles can increase the contact area between the particles and the polymer matrix material, improving their compatibility. Furthermore, the presence of carbon atoms in the carbon-based stannate particles facilitates surface modification with organic compounds, further enhancing their compatibility with the polymer matrix material and promoting the rapid formation of a catalytic char layer during combustion. This achieves highly efficient flame retardancy while reducing the amount of carbon-based stannate particles added, without compromising the material's mechanical properties. In this embodiment, the polymer can be used as an insulating material and / or a flame retardant material.

[0063] Furthermore, conventionally prepared non-flocculated stannates typically require an addition amount of 10 wt% to improve flame retardant and smoke suppression properties. In this embodiment, the addition amount of strontium carbon-based stannate particles or zinc carbon-based stannate particles in the polymer is reduced to 3 wt%~5 wt%. Specific implementation examples: Example 1 (1) Add 15.85 g of strontium chloride to 0.1 L of 1 mol / L sodium stannate solution to obtain the reaction solution.

[0065] (2) The reed flowers were washed, dried and crushed to obtain reed flower templates with an average particle size of about 1 mm. 1 g of reed flower template was added to the reaction solution and the pH was adjusted to 10 with NaOH. The reaction solution was ultrasonically treated at 50℃ for 40 min and allowed to stand for 24 h for co-precipitation reaction. Strontium chloride in the reaction solution reacted with sodium stannate to generate strontium stannate. The mass ratio of reed flower template to strontium stannate was 1:23. Strontium stannate was loaded on the reed flower template to obtain strontium stannate-reed flower template.

[0066] (3) The strontium stannate-reed flower template was washed, filtered and dried, and then heated at a rate of 10℃ / min and calcined at 650℃ for 0.5 h to carbonize the reed flower template and obtain flocculent carbon-based strontium stannate.

[0067] (4) The flocculent carbon-based strontium stannate was crushed to obtain flocculent carbon-based strontium stannate particles with an average particle size of 10 μm. The flocculent carbon-based strontium stannate particles were added to PP at an addition amount of 5 wt% to obtain flame-retardant PP material.

[0068] Example 2 The difference between Example 2 and Example 1 is that: the flocculent carbon-based strontium stannate is pulverized to obtain flocculent carbon-based strontium stannate particles with an average particle size of 1 μm, and the flocculent carbon-based strontium stannate is added to EP at an addition amount of 3 wt% to obtain flame-retardant EP material.

[0069] Example 3 The difference between Example 3 and Example 1 is that: the flocculent carbon-based strontium stannate is pulverized to obtain flocculent carbon-based strontium stannate particles with an average particle size of 50μm, and the flocculent carbon-based strontium stannate is added to PVC at an addition amount of 5wt% to obtain flame-retardant PVC material.

[0070] Example 4 The difference between Example 4 and Example 1 is that the biomass template used is a willow catkin template.

[0071] Example 5 The difference between Example 5 and Example 1 is that the biomass template used is a corn cob template.

[0072] Example 6 The difference between Example 6 and Example 1 is that the mass ratio of reed flower template to strontium stannate is 1:21.

[0073] Example 7 The difference between Example 7 and Example 1 is that the mass ratio of reed flower template to strontium stannate is 1:25.

[0074] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that no flocculent carbon-based strontium stannate particles were added to the PP material.

[0075] Comparative Example 2 The difference between Comparative Example 2 and Example 2 is that no flocculent carbon-based strontium stannate particles were added to the EP material.

[0076] Comparative Example 3 The difference between Comparative Example 3 and Example 3 is that no flocculent carbon-based strontium stannate particles were added to the PVC material.

[0077] Comparative Example 4 The difference between Comparative Example 4 and Example 1 is that no reed flower template was added during the preparation process, and the resulting strontium stannate particles did not have a flocculent morphology.

[0078] Comparative Example 5 The difference between Comparative Example 5 and Example 2 is that no reed flower template was added during the preparation process, and the resulting strontium stannate particles did not have a flocculent morphology.

[0079] Comparative Example 6 The difference between Comparative Example 6 and Example 3 is that no reed flower template was added during the preparation process, and the resulting strontium stannate particles did not have a flocculent morphology.

[0080] Comparative Example 7 The difference between Comparative Example 7 and Example 1 is that reed stalks were used as biomass templates, and the resulting strontium stannate particles had a columnar morphology.

[0081] The preparation method of reed stalk biomass template includes: washing and drying the reed stalks; cutting the dried reed stalks into small segments of about 1-2 cm in length; placing them in a 1-3 mol / L NaOH solution (liquid-to-solid ratio 10:1); and stirring in a constant temperature water bath at 60-80℃ for 1-2 hours to remove hemicellulose and some lignin. After alkali treatment, the reed stalks are washed, dried, and pulverized a second time to obtain the reed stalk biomass template with an average particle size of about 1 mm.

[0082] Comparative Example 8 The difference between Comparative Example 8 and Example 1 is that the mass ratio of reed flower template to strontium stannate is lower, at 1:40.

[0083] Comparative Example 9 The difference between Comparative Example 9 and Example 1 is that the reed flower template and strontium stannate have a higher quality ratio, which is 1:10.

[0084] Test Example 1: The flocculent carbon-based strontium stannate prepared in Example 1 was analyzed by SEM, XRD, energy dispersive spectroscopy, and infrared spectroscopy. The results are as follows: (1) SEM analysis: Reference Figure 1 , Figure 2 Strontium stannate-reed flower template, after calcination, forms 4-8 μm flower-like cluster particles and 10 μm wide nanobands, retaining the reed flower-like morphology.

[0085] (2) XRD analysis: Figure 3 The diffraction peaks in the sample are basically consistent with the characteristic diffraction peaks of strontium stannate in the JCPDS22-1442 cubic crystal system. The diffraction peaks at diffraction angles of 22°, 31°, 45°, 55°, 65° and 74° are assigned to the (200), (220), (400), (422), (440) and (620) diffraction planes, respectively. This indicates that the obtained carbon-based strontium stannate is an ideal perovskite type.

[0086] (3) Energy dispersive spectroscopy analysis: Reference Figure 4 The energy dispersive spectroscopy (EDS) spectrum shows the presence of carbon, oxygen, strontium, and tin atoms. The oxygen content is 67.82%, the sn content is 10.46%, and the sr content is 10.39%, with the sn and sr atomic percentages being approximately 1:1. The carbon content is relatively low, at 8%, which is attributed to carbonization that occurred during the calcination of the reed flower template.

[0087] (4) Infrared analysis: Depend on Figure 5 It can be known that at 858 cm - ¹, 686 cm - ¹, 522 cm - The peak at ¹ represents Sn-O stretching vibration (Sn-O-Sn bridging bonds in the perovskite structure SrSnO3) or Sr-O vibration (metal-oxygen bonds in the perovskite lattice), Sn-O bending vibration (characteristic of octahedral coordination structure), and Sr-O lattice vibration, further proving that the synthesized strontium stannate is a perovskite phase (SrSnO3). 1766 cm⁻¹ - The peak at position ¹ represents the C=O stretching vibration (carbonyl group), indicating the presence of oxidized functional groups (such as carboxylic acid groups -COOH, ketone groups -C=O, or ester groups -COOR) on the surface of the carbon material. This further suggests the presence of an oxidized structure in the carbon component of the sample, which can bind to strontium stannate via chemical bonds (such as Sn-OC). 1459 cm⁻¹ - The peak at position ¹ is COO -Asymmetric stretching vibrations (if it is a carboxylate, such as Sr-OOC-R) indicate that the formation of strontium carboxylate is coordinated with the carboxylate group. This is consistent with the results of XRD and energy dispersive spectroscopy. Therefore, the carbon doping element in the flocculent inorganic particles prepared by this invention can enhance the interaction with organic polymers, thereby enhancing the compatibility with organic polymers.

[0088] In summary, the embodiments of the present invention use reed flowers as a natural hard template, which forms a carbon-based structure after calcination. This not only reduces costs, but also enables the directional growth of carbon-based strontium stannate through the unique flocculent structure of biomass, forming a flocculent morphology with a high specific surface area.

[0089] Test Example 2: The flame-retardant materials in Examples 1-7 and Comparative Examples 1-8 were tested for mechanical properties such as tensile strength and impact strength, as well as for flame-retardant properties in combustion tests. The results are shown in Table 1 below: Table 1. Mechanical and flame-retardant properties of Examples 1-7 and Comparative Examples 1-8

[0090] (I) Examples 1, 4-7, Comparative Examples 1, 4, and 7-8 all prepared PP materials. Among them, the PP materials of Examples 1 and 4-7 all added flocculent carbon-based strontium stannate. The PP material in Comparative Example 1 was a blank control group without the addition of flocculent carbon-based strontium stannate particles. The strontium stannate particles added to the PP material in Comparative Example 4 were not carbon-based strontium stannate and did not have a flocculent morphology. The carbon-based strontium stannate added to the PP material in Comparative Example 7 had a columnar morphology. The amount of reed flower template added to the carbon-based strontium stannate added to the PP material in Comparative Example 8 was too small. The amount of reed flower template added to the carbon-based strontium stannate added to the PP material in Comparative Example 9 was too large.

[0091] 1. The PP flame-retardant material with 5 wt% flocculent strontium carbon-based stannate particles added in Example 1 achieved a limiting oxygen index (LOI) of 32%. Compared to Comparative Example 1, the LIO of Example 1 increased by 6.4%, indicating that the flocculent strontium carbon-based stannate particles have excellent flame-retardant properties. Compared to Comparative Example 1, the tensile strength of Example 1 decreased by only 3.9%, proving that the flocculent strontium carbon-based stannate particles have good compatibility with PP and minimal impact on mechanical properties under high flame-retardant efficiency, thus solving a pain point in the industry.

[0092] 2. In Comparative Example 4, the strontium stannate particles were not carbon-based, and the strontium stannate did not have a flocculent morphology. The limiting oxygen index was low at 28.6%, and the tensile strength decreased significantly. At the same time, the impact strength was also not high. This should be due to the aggregation of strontium stannate and its failure to be fully dispersed in the organic polymer.

[0093] Although Comparative Example 7 used reed stalks as a biomass template, the resulting strontium stannate particles had a columnar morphology and could not improve the compatibility between inorganic particles and organic polymers. The tensile strength and impact strength of Comparative Example 7 were also significantly lower than those of Example 1.

[0094] 3. Example 4 uses willow catkin biomass template, and Example 5 uses corn cob template. The flame-retardant PP materials prepared also have excellent flame-retardant effect and mechanical properties.

[0095] 4. The flame-retardant PP materials prepared in Examples 6 and 7 also exhibit excellent flame-retardant effects. However, in Comparative Example 8, the amount of reed flower template added was too small, and in Comparative Example 9, the amount of reed flower template added was too large. Neither too little nor too much carbon doping could cause the carbon-based stannate particles to form a flocculent morphology. The flame-retardant effects and mechanical properties of Comparative Examples 8 and 9 were significantly lower than those of Example 1.

[0096] (II) EP materials were prepared in Examples 2, 2, and 5. Among them, the EP material in Example 2 had flocculent carbon-based strontium stannate added, the EP material in Comparative Example 2 was a blank control group without flocculent carbon-based strontium stannate particles, and the strontium stannate particles added to the EP material in Comparative Example 5 were non-carbon-based strontium stannate and did not have a flocculent morphology.

[0097] The EP flame retardant material with 3 wt% flocculent carbon-based strontium stannate particles added in Example 2 has a limiting oxygen index of 24.5%, which is 5.4% higher than that of Comparative Example 2.

[0098] Reference Figure 6 , Figure 6 The thermogravimetric curves of the EP material before and after adding flocculent carbon-based strontium stannate particles show that, compared with Comparative Example 2 (pure epoxy resin), the addition of flocculent carbon-based strontium stannate particles in Example 2 (flame-retardant epoxy resin) is beneficial in promoting the early degradation of some materials, but overall it slows down the combustion rate of the material and increases the residual carbon content, thus achieving the effect of flame retardancy and smoke suppression in the solid phase.

[0099] In Example 2, the tensile strength of the EP material was 38.06 MPa, and the impact strength was 1.5 J / cm. 2 The mechanical properties of the EP materials in both Comparative Examples 2 and 5 are enhanced. The non-carbon-based strontium stannate particles in Comparative Example 5 also lack a flocculent morphology and have a low limiting oxygen index of 21.1%, which cannot improve the compatibility between inorganic particles and organic polymers. Therefore, the tensile strength and impact strength of Comparative Example 5 are significantly lower than those of Example 2.

[0100] (III) PVC materials were prepared in Examples 3, 3, and 6. Among them, the PVC material in Example 3 had flocculent carbon-based strontium stannate added, the PVC material in Comparative Example 3 was a blank control group without flocculent carbon-based strontium stannate particles, and the strontium stannate particles added to the PVC material in Comparative Example 6 were non-carbon-based strontium stannate and did not have a flocculent morphology.

[0101] The PVC flame retardant material with 5 wt% flocculent carbon-based strontium stannate particles added in Example 3 achieved a limiting oxygen index of 33.1%, which is 8.6% higher than that of Comparative Example 3.

[0102] Reference Figure 7 , Figure 7 The thermogravimetric curves of PVC material before and after adding flocculent carbon-based strontium stannate particles show that, compared with Comparative Example 3 (PVC before flame retardancy), the addition of flocculent carbon-based strontium stannate particles in Example 3 (flame retardant PVC) is beneficial in promoting the early degradation of some materials, but overall it slows down the burning rate of the material and increases the residual carbon content, thus achieving the effect of flame retardancy and smoke suppression in the solid phase.

[0103] In Example 3, the tensile strength reached 18.65 MPa and the elongation at break was 432.56%, both of which showed enhanced mechanical properties compared to the PVC materials in Comparative Examples 3 and 6. The non-carbon-based strontium stannate particles in Comparative Example 6 also lacked a flocculent morphology and had a low limiting oxygen index of 30.8%, failing to improve the compatibility between inorganic particles and organic polymers. Therefore, the tensile strength of Comparative Example 6 was significantly lower than that of Example 3.

[0104] In summary, when the prepared flocculent strontium stannate carbonaceous particles were applied to matrix materials such as polyvinyl chloride, polypropylene, and epoxy resin, the oxygen index of the samples after flame retardation increased by 5 to 10 percentage points compared with the samples before flame retardation when the amount of flocculent strontium stannate carbonaceous particles added was 3% to 5%, indicating that the flame retardant has excellent flame retardant effect.

[0105] By utilizing the synergistic effect of reed flower templates and calcination processes, a flocculent carbon-based strontium stannate particle flame-retardant material with high specific surface area and excellent compatibility was prepared. This flame-retardant material can significantly improve the flame-retardant and smoke-suppressing properties of polymer matrix materials while maintaining mechanical properties, offering advantages such as high efficiency, environmental friendliness, and low cost. The above embodiments only illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A carbon-based stannate material, characterized in that, Includes carbon-based stannate particles, wherein the carbon-based stannate particles comprise stannate and carbon doping elements, and the carbon-based stannate particles are in a flocculent state; The carbon doping element accounts for 5% to 10% of the atomic weight of the carbon-based stannate particles.

2. The carbon-based stannate material of claim 1, wherein, The stannate includes one or more of zinc stannate, strontium stannate, and magnesium stannate.

3. The carbon-based stannate material of claim 1, wherein, The average particle size of the carbon-based stannate particles is 1 μm to 50 μm.

4. The carbon-based stannate material of claim 1, wherein, The stannate has a perovskite crystal structure.

5. A method of producing a carbon-based stannate material as claimed in any one of claims 1 to 4, characterized in that, Includes the following steps: A soluble metal salt and a soluble stannate are mixed and added to a solvent to obtain a reaction solution; the soluble metal salt includes soluble strontium salt, soluble zinc salt, or soluble magnesium salt. A flocculent biomass template is added to the reaction solution to carry out a chemical reaction, in which the soluble metal salt and the soluble stannate react to generate an inorganic compound of metal-stannate, and the inorganic compound is loaded on the flocculent biomass template to obtain a complex of the inorganic compound of metal-stannate and the biomass template; the mass ratio of the flocculent biomass template to the inorganic compound of metal-stannate is 1:30 to 1:

20. The composite is calcined to carbonize the flocculent biomass template, thereby obtaining the carbon-based stannate material.

6. The method for preparing the carbon-based stannate material according to claim 5, characterized in that, The flocculent biomass template includes one or more of the following: reed flowers, willow catkins, and corn ears.

7. The method of claim 5, wherein the carbon-based stannate material is prepared by a process comprising: The calcination temperature is 600℃~700℃.

8. A polymer characterized in that, It includes a polymer matrix material and a carbon-based stannate material doped in the polymer matrix material, wherein the carbon-based stannate material is the carbon-based stannate material according to any one of claims 1 to 4, or is prepared by any one of the preparation methods according to claims 5 to 7.

9. The polymer of claim 8, wherein, The amount of carbon-based stannate particles added is 3wt%~5wt%.

10. The polymer according to claim 8, characterized in that, The polymer matrix material is rubber or resin.

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