Polymethoxylated flavone co-hybridized hydromagnesite composite powder as well as preparation method and application thereof in natural rubber master batch

Abstract

The invention belongs to the technical field of preparation of green materials, and particularly relates to polymethoxylated flavone co-hybridized hydromagnesite composite powder, a preparation method thereof and application of the polymethoxylated flavone co-hybridized hydromagnesite composite powder in natural rubber master batches. The polymethoxylated flavone co-hybridized hydromagnesite composite powder provided by the invention comprises hydromagnesite, a glycine derivative coated on the surface of the hydromagnesite, and polymethoxylated flavone coated on the surface of the glycine derivative, the hydromagnesite and the glycine derivative are connected through an ester bond, and the polymethoxylated flavone and the glycine derivative are connected through electrostatic adsorption. The polymethoxylated flavone co-hybridized hydromagnesite composite powder provided by the invention not only has better particle size distribution, structural stability, low oil absorption value, low surface polarity and difficulty in agglomeration, but also has high dispersity in rubber, and a composite material prepared from the polymethoxylated flavone co-hybridized hydromagnesite composite powder and the rubber has high mechanical properties and can achieve internal and external synergistic flame retardance and smoke suppression.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of green material preparation, and particularly relates to a multi-methoxy flavone co-hybridized hydromagnesite composite powder, a preparation method thereof and application thereof in natural rubber masterbatch. BACKGROUND

[0002] Natural rubber is one of the main materials for making the insulating layer and protective sleeve of energy cables, and the main structure of which is rubber hydrocarbon (polyisoprene). As a crystalline rubber, rubber hydrocarbon has good reinforcing performance and high mechanical strength, and also has good electrical insulation and insulation resistance, and in addition, has good elasticity and cold resistance, good low-temperature working conditions, strong universality, can be blended with various rubbers and plastics, and has excellent processing performance. However, rubber hydrocarbon has poor heat stability in air and is easy to burn, and the burning is accompanied by the release of dense smoke and irritating gas, which seriously restricts its application in energy cables. Natural inorganic mineral powder is a widely available and low-cost solid powder particle, and the thermal stability and smoke suppression effect of hydromagnesite are better, but a large amount of addition is needed to meet the basic flame retardant requirement. Moreover, the addition of natural inorganic mineral powder will greatly damage the mechanical properties of natural rubber products. In addition, the natural inorganic mineral powder is easy to absorb moisture and agglomerate, and even to form a lump during storage, which seriously restricts the application of the powder in the new energy field. With the increasing maturity and wide application of superfine technology, the surface structure modification process of natural inorganic mineral powder needs to be developed to further better adapt to the application requirements of different occasions.

[0003] Conventional silane coupling agents are widely used for surface modification of inorganic mineral powder, but such coupling agents have single function, poor ablation resistance, poor thermal stability, and are difficult to synergistically play the effect with natural hydromagnesite in the inner layer of natural rubber. SUMMARY

[0004] Therefore, the present application aims to provide a multi-methoxy flavone co-hybridized hydromagnesite composite powder, a preparation method thereof and application thereof in natural rubber masterbatch. The multi-methoxy flavone co-hybridized hydromagnesite composite powder provided by the present application has good particle size distribution, structural stability, low oil absorption value, low surface polarity, and is not easy to agglomerate, and also has high dispersibility in rubber, and the composite material made of rubber has high mechanical properties, and can synergistically play the effect of flame retardation and smoke suppression.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0006] The application provides a polymethoxyflavone co-hybrid hydromagnesite composite powder, which comprises hydromagnesite, glycine derivatives coated on the surface of the hydromagnesite, and polymethoxyflavone coated on the surface of the glycine derivatives.

[0007] The hydromagnesite and the glycine derivatives are connected by ester bonds, and the polymethoxyflavone and the glycine derivatives are connected by electrostatic adsorption.

[0008] Preferably, the median particle size of the polymethoxyflavone co-hybrid hydromagnesite composite powder is 1.0-4.0 mu m.

[0009] Preferably, the median particle size of the hydromagnesite is 0.8-3.6 mu m, and the total content of magnesium carbonate and magnesium hydroxide in the hydromagnesite is greater than or equal to 90 wt%.

[0010] Preferably, the glycine derivative is N,N-dimethylglycine, and the polymethoxyflavone is narirutin.

[0011] The application also provides a preparation method of the polymethoxyflavone co-hybrid hydromagnesite composite powder.

[0012] The dispersion liquid of the hydromagnesite and the solution of the glycine derivative are mixed to perform esterification reaction, so as to obtain glycine derivative activated hydromagnesite.

[0013] The glycine derivative activated hydromagnesite and the solution of the polymethoxyflavone are mixed to perform hybridization treatment, so as to obtain the polymethoxyflavone co-hybrid hydromagnesite composite powder.

[0014] Preferably, the ratio of the amount of substance of the glycine derivative to the mass of the hydromagnesite is (1-10) mol:10 kg.

[0015] Preferably, the esterification reaction is performed under the conditions of heating, stirring and ultrasonic; the temperature of the heating is 30-60 DEG C; the stirring rate is 500-2000 rpm; the ultrasonic power is 15-80 kHz; and the esterification reaction time is 0.2-1.0 h.

[0016] Preferably, the ratio of the amount of substance of the polymethoxyflavone to the mass of the glycine derivative activated hydromagnesite is (1-5) mol:10 kg.

[0017] Preferably, the hybrid treatment is heating stirring and low-temperature stirring in sequence; the temperature of the heating stirring is 60-100 DEG C, the time is 10-45 min, and the speed is 1000-6000 rpm; after the heating stirring, the method further comprises: stopping heating, cooling to room temperature, and then further cooling to 1-10 DEG C for low-temperature stirring; the speed of the low-temperature stirring is 500-3000 rpm, and the time is 10-60 min.

[0018] The application further provides application of the multi-methoxy flavone co-hybrid hydromagnesite composite powder in natural rubber masterbatch.

[0019] The application provides a multi-methoxy flavone co-hybrid hydromagnesite composite powder, which comprises hydromagnesite, glycine derivatives coated on the surface of the hydromagnesite, and multi-methoxy flavones coated on the surface of the glycine derivatives; the hydromagnesite and the glycine derivatives are connected by an ester bond, and the multi-methoxy flavones and the glycine derivatives are connected by electrostatic adsorption.

[0020] The polymethoxyflavonoids co-hybridized hydromagnesite composite powder provided by the present invention is an organic-inorganic functional composite particle with an inner-middle-outer three-layer core-shell structure. The multi-layer shielding and wrapping of glycine derivatives and polymethoxyflavonoids can significantly improve the surface polarity of natural inorganic mineral powder (hydromagnesite), reduce the adsorption effect of its surface on processing aids, and greatly save processing costs. Due to the introduction of aromatic compounds - polymethoxyflavonoids, the dispersibility of the composite powder in low-polarity natural rubber can also be solved. The synergistic introduction of organic and inorganic components can realize the functional enhancement of the multifunctional component in the rubber matrix, that is, a green, environmentally friendly and sustainable multi-component functional composite powder is provided; the polymethoxyflavonoids in the outer layer contain a large amount of conjugated The structure and aromatic rings are rapidly cross-linked into rings and further charred during the combustion process. The natural hydromagnesite inside will quickly form a large amount of MgO ceramic precursors during combustion, which has good heat resistance and can serve as a skeleton to support the external carbon layer, thereby forming a good physical barrier layer. The introduction of nitrogen elements in glycine derivatives can play a good role in diluting nitrogen oxides to a certain extent. The internal hydromagnesite also has good smoke suppression and dehydration heat absorption functions, and can produce a synergistic flame retardant effect with the external glycine derivatives and polymethoxyflavonoids, comprehensively improving the flame retardant, smoke suppression, carbonization promotion, dilution and other properties of the composite material formed with rubber, that is, effective barrier and dilution effects occur in the condensed phase and gas phase at the same time to strengthen the combustion process and cut off the path. Moreover, the co-hybridized hydromagnesite composite powder provided by the present invention not only has good particle size distribution, structural stability and low oil absorption value, but also has high dispersibility in rubber as an organic-inorganic composite functional powder, can improve the mechanical properties of the rubber composite material, and can also provide internal and external synergistic flame retardant and smoke suppression properties. The co-hybridized hydromagnesite composite powder provided by the present invention can improve the defects of natural hydromagnesite after ultrafine processing, such as high surface polarity, easy agglomeration, and high oil absorption value, so that traditional inorganic mineral powders can be high-valued and multifunctionalized. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the process for preparing polymethoxyflavonoids co-hybridized hydromagnesite composite powder (Nob-Gly-UNHM) in an embodiment;

[0022] Figure 2 Schematic diagram of the structure of the polymethoxyflavonoids co-hybridized hydromagnesite composite powder (Nob-Gly-UNHM) prepared in the example.

[0023] Figure 3 This is the SEM image of the polymethoxyflavonoid co-hybridized hydromagnesite composite powder (Nob-Gly-UNHM) prepared in Example 1. DETAILED DESCRIPTION

[0024] The application provides a polymethoxyflavone co-hybrid hydromagnesite composite powder, which comprises hydromagnesite, glycine derivatives coated on the surface of the hydromagnesite, and polymethoxyflavone coated on the surface of the glycine derivatives.

[0025] The hydromagnesite and the glycine derivatives are connected by an ester bond, and the polymethoxyflavone and the glycine derivatives are connected by electrostatic adsorption.

[0026] Unless otherwise specified, the application does not have special requirements for the source of the raw materials, and commercially available goods known to those skilled in the art can be used.

[0027] As an embodiment, the median particle size (D 50 ) of the polymethoxyflavone co-hybrid hydromagnesite composite powder is 1.0-4.0 μm, and in specific embodiments, is 2.0 μm.

[0028] As an embodiment, the total content of magnesium carbonate and magnesium hydroxide in the hydromagnesite is ≥ 90 wt%; the hydromagnesite is obtained by physical grinding and magnetic separation grading of natural hydromagnesite with a total content of magnesium carbonate and magnesium hydroxide ≥ 90 wt%; the median particle size (D 50 ) of the hydromagnesite is 0.8-3.6 μm, and in specific embodiments, is 1.8 μm; the glycine derivative is N,N-dimethylglycine; the structural formula of the N,N-dimethylglycine is shown in formula I; and the polymethoxyflavone is nobiletin; the structural formula of the nobiletin is shown in formula II.

[0029]

[0030] The glycine derivative, the natural plant extract (nobiletin), and the natural inorganic mineral powder (hydromagnesite) are combined with each other, and the products are all from nature, and have the characteristics of being green, renewable, and environmentally friendly. The organic-inorganic functional composite particles with a core-shell structure are prepared from the glycine derivative, the nobiletin, and the hydromagnesite, the multi-layer shielding and wrapping of the glycine derivative and the nobiletin can significantly improve the surface polarity of the natural inorganic mineral powder, reduce the adsorption effect of the surface of the natural inorganic mineral powder on processing aids, and greatly save the processing cost. The introduction of the aromatic compound can also solve the dispersibility of the composite powder in low-polarity natural rubber. The synergistic introduction of the organic and inorganic components can realize the functional enhancement of the multifunctional components in the rubber matrix, that is, a green, environmentally friendly, and sustainable multifunctional component is constructed to obtain a functional composite powder.

[0031] The application also provides a preparation method of the polymethoxyflavone co-hybrid hydromagnesite composite powder.

[0032] The dispersion liquid of hydromagnesite and the solution of glycine derivative are mixed to perform esterification reaction, so as to obtain glycine derivative activated hydromagnesite.

[0033] The solution of the glycine derivative activated hydromagnesite and polymethoxyflavone is mixed to perform hybridization treatment, so as to obtain polymethoxyflavone co-hybridized hydromagnesite composite powder.

[0034] The dispersion liquid of hydromagnesite and the solution of glycine derivative are mixed to perform esterification reaction, so as to obtain glycine derivative activated hydromagnesite.

[0035] As an embodiment, the ratio of the amount of substance of the glycine derivative to the mass of the hydromagnesite is (1-10) mol:10 kg, and in a specific embodiment, 1 mol:10 kg, 5 mol:10 kg or 10 mol:10 kg.

[0036] As an embodiment, the first solvent in the solution of the glycine derivative comprises one or more of tetrahydrofuran, dimethyl sulfoxide, N,N-dimethylformamide, acetonitrile and ethyl acetate, and in a specific embodiment, tetrahydrofuran or acetonitrile; the preparation method of the solution of the glycine derivative comprises adding the glycine derivative into the first solvent, and stirring to obtain the solution of the glycine derivative; the temperature of the mixing is 30-60 DEG C, and in a specific embodiment, 30 DEG C, 40 DEG C or 60 DEG C; the stirring time is 0.5-2.0 h, and in a specific embodiment, 0.5 h, 1.0 h or 2.0 h; the stirring rate is 100-1000 rpm, and in a specific embodiment, 100 rpm, 500 rpm or 1000 rpm; and the concentration of the solution of the glycine derivative is 1-10 mol / L, and in a specific embodiment, 1 mol / L, 5 mol / L or 10 mol / L.

[0037] As an embodiment, the second solvent in the dispersion liquid of the high-magnesium hydromagnesite is an alcohol; the alcohol comprises one or more of methanol, ethanol, propanol, ethylene glycol and 1,2-propanediol, and in a specific embodiment, methanol; when the second solvent is one or more of the above-mentioned alcohols, the second solvent is obtained by mixing the alcohols of different types in equal volumes; the preparation method of the dispersion liquid of the hydromagnesite comprises dispersing the hydromagnesite in the second solvent to obtain the dispersion liquid of the hydromagnesite; the dispersing is performed at room temperature and under stirring; the room temperature is 25 DEG C; the stirring rate is 1000-3000 rpm, and in a specific embodiment, 1000 rpm, 1500 rpm or 3000 rpm; the dispersing time is 0.5-3.0 h, and in a specific embodiment, 0.5 h, 1.5 h or 3.0 h; and the molar concentration of the hydromagnesite in the dispersion liquid of the high-magnesium hydromagnesite is 1-10 mol / L, and in a specific embodiment, 1 mol / L, 5 mol / L or 10 mol / L.

[0038] As an implementation form, the mixing of the brucite dispersion and the solution of the glycine derivative is adding the solution of the glycine derivative into the brucite dispersion at a constant speed; the adding speed is 10-30 mL / min, and in specific embodiments, it is 10 mL / min, 20 mL / min or 30 mL / min.

[0039] As an implementation form, the esterification reaction is carried out under the conditions of heating, stirring and ultrasonic; the heating temperature is 30-60℃, and in specific embodiments, it is 30℃ or 45℃; the stirring speed is 500-2000 rpm, and in specific embodiments, it is 500 rpm, 1000 rpm or 2000 rpm; the ultrasonic power is 15-80 kHz, and in specific embodiments, it is 15 kHz, 40 kHz or 80 kHz; the esterification reaction time is 0.2-1.0 h, and in specific embodiments, it is 0.2 h, 0.5 h or 1.0 h.

[0040] As an implementation form, after the esterification reaction, the product of the esterification reaction is sequentially subjected to solid-liquid separation, first precipitation and first drying to obtain the glycine derivative activated brucite; the solid-liquid separation is centrifugation after filtration; the filtration is suction filtration; the suction filtration is carried out using fast filter paper or medium-speed filter paper, and in specific embodiments, it is fast filter paper; the vacuum degree of the suction filtration is -0.09 to -0.07 MPa, and in specific embodiments, it is -0.09 MPa, -0.08 MPa or -0.07 MPa; during the suction filtration, the filter residue is repeatedly washed with a mixed solution of alcohol and water; the number of repeated washing is 1-4 times, and in specific embodiments, it is 1 time, 2 times, 3 times or 4 times; the alcohol includes one or more of methanol, ethanol, 1,3-propanediol and propanol, and in specific embodiments, it is methanol; the water is twice-purified water; the volume ratio of the alcohol to water is 1-10:1, and in specific embodiments, it is 1:1, 5:1 or 10:1.

[0041] As an implementation form, the centrifugation process is placing the solid obtained by the solid-liquid separation into a centrifuge tube of a centrifuge for centrifugation, adding water in each centrifuge tube, and controlling the solid content of each centrifuge tube to be 1-30 mg / mL, and in specific embodiments, it is 1 mg / mL, 15 mg / mL or 30 mg / mL; the centrifugation speed is 1000-10000 rpm, and in specific embodiments, it is 1000 rpm, 4000 rpm or 10000 rpm; the centrifugation time is 5-45 min, and in specific embodiments, it is 5 min, 25 min or 45 min; the number of centrifugation is 1-5 times, and in specific embodiments, it is 1 time, 3 times or 5 times; the centrifugation is carried out at room temperature; the room temperature is 25℃.

[0042] As an embodiment, the first precipitation process is that the centrifuged product is placed in a surface metal tray with a bottom valve, then an alcohol-water mixed solution is added for standing, the bottom valve is opened every 1-2 hours to release the alcohol-water mixed solution, then the bottom valve is closed and new immersion solution is added for continuing immersion; the alcohol in the alcohol-water mixed solution includes one or more of methanol, ethanol and propanol, and in a specific embodiment, the alcohol is methanol; the volume ratio of alcohol to water in the alcohol-water mixed solution is 1:1-20, and in a specific embodiment, the volume ratio is 1:1, 1:10 or 1:20; the volume-mass ratio of the alcohol-water mixed solution to the centrifuged product is (10-30) mL:10 mg, and in a specific embodiment, the volume-mass ratio is 10 mL:10 mg, 20 mL:10 mg or 30 mL:10 mg; the standing temperature is 1-10℃, and in a specific embodiment, the standing temperature is 1℃, 5℃ or 10℃; the total standing time is 1.0-36.0 h, and in a specific embodiment, the total standing time is 1.0 h, 18.0 h or 36.0 h; in a specific embodiment, the bottom valve is opened every 0.5 h, 1.0 h or 1.5 h to release the alcohol-water mixed solution, then the bottom valve is closed and new immersion solution is added for continuing immersion; the new immersion solution is water, and in a specific embodiment, the new immersion solution is double-distilled water; the process of adding new immersion solution for continuing immersion is repeated 1-4 times, and in a specific embodiment, the process is repeated 1 time, 3 times or 4 times.

[0043] As an embodiment, the first drying is freeze-drying; the freeze-drying temperature is -30--10℃, and in a specific embodiment, the freeze-drying temperature is -10℃, -20℃ or -30℃; the freeze-drying time is 12-72 h, and in a specific embodiment, the freeze-drying time is 12 h, 36 h or 72 h.

[0044] After the glycine derivative-activated hydromagnesite is obtained, the glycine derivative-activated hydromagnesite and a solution of polymethoxyflavone are mixed for hybridization treatment to obtain polymethoxyflavone co-hybridized hydromagnesite composite powder.

[0045] As an embodiment, the third solvent in the solution of the polymethoxyflavone is an alcohol solution; the alcohol solution comprises one or more of methanol, ethanol, propanol, ethylene glycol and 1,2-propanediol, and in a specific embodiment, the alcohol solution is methanol; when the third solvent is one of the above, the third solvent is obtained by mixing several different types of alcohol solutions in equal volumes; the preparation method of the solution of the polymethoxyflavone is as follows: adding the polymethoxyflavone to the third solvent and stirring until dissolved; the ratio of the amount of substance of the polymethoxyflavone to the mass of the glycine derivative activated water magnesite is (1-5) mol:10 kg, and in a specific embodiment, the ratio is 1 mol:10 kg, 3 mol:10 kg or 5 mol:10 kg; the stirring rate is 600-1600 rpm, and in a specific embodiment, the rate is 600 rpm, 1000 rpm or 1600 rpm; the stirring time is 1-12 h, and in a specific embodiment, the time is 1 h, 6 h or 12 h; the stirring temperature is 25-50°C, and in a specific embodiment, the temperature is 25°C, 30°C or 50°C; the concentration of the polymethoxyflavone in the solution of the polymethoxyflavone is 1-3 mol / L, and in a specific embodiment, the concentration is 1 mol / L, 2 mol / L or 3 mol / L.

[0046] When the molar mass ratio of the glycine derivative to the natural high-magnesium water magnesite is less than 1 mol:10 kg, the amount of the glycine derivative added may be too low to effectively cover and shield the natural high-magnesium water magnesite, and the subsequent adsorption effect of the polymethoxyflavone may be reduced, ultimately resulting in limited functionalization enhancement and poor comprehensive performance of the composite powder. On the other hand, when the molar mass ratio of the glycine derivative to the natural high-magnesium water magnesite is greater than 10 mol:10 kg, the content of the glycine derivative on the surface may be too high, and most of the glycine derivative may exist on the surface of the natural high-magnesium water magnesite in a physically weakly adsorbed manner and may be unevenly dispersed, which is not conducive to the further functionalization modification of the powder and may even wrap multiple natural high-magnesium water magnesite particles, ultimately making it difficult to effectively disperse in the polymer matrix and forming stress concentration points to induce defect derivation.

[0047] As an embodiment, the mixing of the glycine derivative activated hydromagnesite and the solution of polymethoxyflavones is: the glycine derivative activated hydromagnesite is placed in a stirrer, pre-stirring is performed before temperature rising stirring, and the solution of polymethoxyflavones is added in the temperature rising process; the stirring rate of the stirrer is 1000-6000 rpm, and in specific embodiments, it is 3000 rpm; the pre-stirring is performed at room temperature; the pre-stirring time is 0.5-2.5 h, and in specific embodiments, it is 0.5 h, 1.5 h or 2.5 h; the temperature rising stirring is uniform temperature rising; the temperature rising stirring is to 60-100℃, and in specific embodiments, it is 60℃, 80℃ or 100℃; the adding mode is spraying; and the adding rate is 5-30 mL / min, and in specific embodiments, it is 5 mL / min, 15 mL / min or 30 mL / min.

[0048] As an embodiment, the hybrid treatment is heating stirring and low temperature stirring in sequence; the heating stirring temperature is 60-100℃, and in specific embodiments, it is 60℃, 80℃ or 100℃; the heating stirring time is 10-45 min, and in specific embodiments, it is 10 min, 25 min or 45 min; the heating stirring rate is 1000-6000 rpm, and in specific embodiments, it is 1000 rpm, 3000 rpm or 6000 rpm; after the heating stirring, further comprising: stopping heating, cooling to room temperature, and then further cooling to 1-10℃ for low temperature stirring, and in specific embodiments, the temperature is 1℃, 5℃ or 10℃; the low temperature stirring rate is 500-3000 rpm, and in specific embodiments, it is 500 rpm, 1500 rpm or 3000 rpm; the low temperature stirring time is 10-60 min, and in specific embodiments, it is 10 min, 30 min or 60 min.

[0049] As an embodiment, after the hybrid treatment, further comprising: sequentially subjecting the hybrid treatment product to second precipitation, dust removal and second drying to obtain polymethoxyflavone co-hybrid hydromagnesite composite powder.

[0050] As an embodiment, the second precipitation is that the mixture after room temperature stirring is placed at room temperature for standing; the standing time is 0.1-1.0 h, and in specific embodiments, it is 0.1 h, 0.5 h or 1.0 h; the dust removal equipment is a cyclone separator; the dust removal power is 200-800 W, and in specific embodiments, it is 200 W, 600 W or 800 W; the rotation speed is 1200-3200 rpm, and in specific embodiments, it is 1200 rpm, 2200 rpm or 3200 rpm; the air volume is 50-250 m 3 / h, and in specific embodiments, it is 50 m 3 / h, 150 m3 / h or 250 m 3 / h, the number of repetitions is 1-3 times, and in specific embodiments, 1 time, 2 times or 3 times; the second drying is flash drying; the temperature of the flash drying is 190-220 DEG C, and in specific embodiments, 190 DEG C, 200 DEG C or 220 DEG C, the time is 1-6 min, and in specific embodiments, 1 min, 3 min or 6 min, and the power is 600-1700 W, and in specific embodiments, 600 W, 1200 W or 1700 W.

[0051] Figure 1 A flowchart for preparing the polymethoxyflavone co-hybrid hydromagnesite composite powder (Nob-Gly-UNHM) of the embodiments is shown. Figure 1 As shown in the figure, the present application mixes the glycine derivative with the hydromagnesite, and the carboxyl group of the glycine derivative and the hydroxyl group on the surface of the hydromagnesite perform esterification reaction and dehydration, thereby coating the glycine derivative on the surface of the hydromagnesite to obtain the glycine derivative activated hydromagnesite, and then the nobiletin is coated on the surface of the glycine derivative activated hydromagnesite by electrostatic adsorption to obtain the polymethoxyflavone co-hybrid hydromagnesite composite powder.

[0052] The present application constructs the co-hybrid hydromagnesite composite powder with an inner-middle-outer three-layer structure by a simple physical and chemical combination method. In terms of function, the outer polymethoxyflavone contains a large number of conjugated structures and aromatic rings, which are rapidly crosslinked into rings and further carbonized during combustion. The internal natural hydromagnesite quickly forms a large amount of MgO ceramic precursor during combustion, has good heat resistance, and can support the outer carbon layer as a skeleton to form a better physical barrier layer. The introduction of nitrogen elements in the glycine derivative can to some extent play a good effect of diluting nitrogen oxides. The internal hydromagnesite also has good smoke suppression and dehydration endothermic functions, and can occur synergistic flame retardation effect with the outer glycine derivative and polymethoxyflavone, thereby comprehensively improving the performance of the composite material such as flame retardation, smoke suppression, carbon promotion and dilution, that is, effectively blocking and diluting effects in the condensed phase and gas phase to strengthen the combustion process and cut off the path.

[0053] The present application realizes the preparation of the polymethoxyflavone co-hybrid hydromagnesite composite powder by a two-step method, has a higher yield, a simple and easy-to-operate preparation process, a better composite effect, and the obtained co-hybrid hydromagnesite composite powder is a white or off-white powder, which is beneficial to further adding color master batch, can effectively expand the application value of inorganic mineral powder, and can promote the wide application of traditional natural products in industrialized products.

[0054] The present application also provides the application of the polymethoxyflavone co-hybrid hydromagnesite composite powder in the above technical solution or the polymethoxyflavone co-hybrid hydromagnesite composite powder prepared by the preparation method in the above technical solution in natural rubber master batch.

[0055] As an implementation form, the preparation method of the natural rubber master batch is adding zinc oxide, stearic acid, plasticizer and antioxidant into natural rubber, sequentially performing first mixing and degumming, then adding carbon black, white carbon black, polymethoxyflavone co-hybrid hydromagnesite composite powder to perform second mixing, finally adding sulfur and accelerator to sequentially perform thin passing and sheeting, and then standing, vulcanizing to obtain the natural rubber master batch; the antioxidant comprises 4010; the accelerator comprises CZ and DM, and the mass ratio of the CZ and DM is 3:1; and the plasticizer is paraffin.

[0056] The preparation raw materials of the natural rubber master batch comprise the following components in mass fraction: 100 parts of natural rubber, 5 parts of zinc oxide, 2 parts of stearic acid, 1.5 parts of antioxidant, 0.3 parts of carbon black, 5 parts of white carbon black, 20 parts of polymethoxyflavone co-hybrid hydromagnesite composite powder, 1.5 parts of sulfur, 0.5 parts of accelerator and 3 parts of plasticizer.

[0057] As an implementation form, the temperature of the first mixing is 145℃, and the time is 8min in specific embodiments; the temperature of the degumming is 120℃; the second mixing is sequentially performed low-temperature mixing and high-temperature mixing; the temperature of the low-temperature mixing is 130℃, and the time is 5min; the temperature of the high-temperature mixing is 155℃, and the time is 7min in specific embodiments; the roll gap of the thin passing is 1mm; the number of the thin passing is 5-6 times; the sheeting is to adjust the roll gap to 3mm; the standing is performed at room temperature; the time of the standing is 8h; the equipment for the vulcanizing is a flat vulcanizing machine; and the temperature of the vulcanizing is 160℃, and the time is 6min.

[0058] The technical solutions in the application will be described clearly and completely below in combination with the embodiments in the application, but they should not be understood as limitations to the protection scope of the application.

[0059] Example 1

[0060] (1) 515g of glycine derivative (N,N-dimethylglycine) was added to acetonitrile at 40℃, and stirred at 500rpm for 1.0h to obtain solution 1 with a concentration of 5mol / L;

[0061] (2) 10kg of superfine high-magnesium hydromagnesite (median particle size D 50 1.8μm) was dispersed in a methanol solution at room temperature (25℃) and stirred at 1500rpm for 1.5h to obtain dispersion 2 of superfine hydromagnesite with a molar concentration of 5mol / L;

[0062] (3) adding solution 1 to dispersion 2 at a rate of 20 mL / min, stirring at 1000 rpm and ultrasonicating at 40 kHz at 45°C for 0.5 h to obtain glycine derivative activated hydromagnesite (Gly-UNHM) with a ratio of the amount of substance of glycine derivative to the mass of ultra-fine hydromagnesite of 5 mol:10 kg, and then subjecting the obtained glycine derivative activated hydromagnesite (Gly-UNHM) crude product to filtration, centrifugation, precipitation and low-temperature drying in sequence, wherein a fast filter paper is used in the filtration process, the vacuum degree is controlled to be -0.08 MPa, a mixed solution of methanol and double-distilled water is used to repeatedly rinse the filter paper twice during the filtration process, the volume ratio of methanol to double-distilled water is controlled to be 10:1, the filtration product is placed in a centrifuge for centrifugation at room temperature (25°C), double-distilled water is added to each centrifuge tube, the solid content of each centrifuge tube is controlled to be 15 mg / mL, the centrifugation is performed at a speed of 4000 rpm for 25 min, and the centrifugation is performed for 3 times, the centrifugation product is placed in a surface metal tray with a bottom valve for standing, an appropriate amount of a mixed solution of double-distilled water and methanol is added to the tray, the volume ratio of methanol to double-distilled water is controlled to be 1:10, the volume-mass ratio of the alcohol / water mixed solution to the obtained centrifugation product is controlled to be 20 mL:10 mg, the standing temperature is controlled to be 5°C, the standing time is controlled to be 18.0 h, the alcohol / water mixed solution is discharged by opening the bottom valve every 1.5 h during the precipitation process, then the bottom valve is closed and double-distilled water is added for further immersion, and this process is repeated for 3 times, and the obtained precipitation product is freeze-dried at -20°C for 36 h to obtain glycine derivative activated hydromagnesite (Gly-UNHM) composite powder;

[0063] (4) adding 1206 g of nobiletin to methanol, stirring at 1000 rpm at 30°C for 6 h until nobiletin is dissolved to obtain solution 3 with a concentration of 3 mol / L;

[0064] (5) placing the glycine derivative activated hydromagnesite (Gly-UNHM) composite powder (10 kg) in a high-speed stirrer, pre-stirring at 3000 rpm at room temperature for 1.5 h, then uniformly increasing the temperature to 80°C, adding solution 3 to the high-speed stirrer in the form of a spray at an adding rate of 15 mL / min during the temperature increasing process, controlling the ratio of the amount of substance of nobiletin to the mass of glycine derivative activated hydromagnesite to be 3 mol:10 kg, continuing to stir for 25 min after the spraying is completed, stopping heating and cooling to room temperature, further reducing the temperature for low-temperature stirring, continuing to stir at 1500 rpm at 5°C for 30 min, and then standing at room temperature for 0.5 h for precipitation, and then placing the obtained precipitate in a cyclone separator, separating the precipitate at a power of 600 W and a speed of 2200 rpm, and then collecting the glycine derivative activated hydromagnesite (Gly-UNHM) composite powder on a filter paper, and then drying the glycine derivative activated hydromagnesite (Gly-UNHM) composite powder at 60°C for 6 h to obtain the glycine derivative activated hydromagnesite (Gly-UNHM) composite powder; 3 / h air flow, and repeated the dust removal process twice, and finally, the multi-methoxy flavone co-hybrid hydromagnesite composite powder (Nob-Gly-UNHM) (median particle size D 50 was 2.0 pm).

[0065] Example 2

[0066] (1) 103 g of the glycine derivative (N,N-dimethylglycine) was added to acetonitrile at 30 °C, and stirred at 100 rpm for 2.0 h to obtain a solution 1 with a concentration of 1 mol / L;

[0067] (2) 10 kg of superfine high-magnesium hydromagnesite (median particle size D 50 was 1.8 pm) was dispersed in a methanol solution at room temperature (25 °C) and stirred at 1000 rpm for 3.0 h to obtain a dispersion 2 of superfine hydromagnesite with a molar concentration of 1 mol / L;

[0068] (3) The solution 1 was added to the dispersion 2 at a rate of 10 mL / min, and ultrasonic treatment was performed at 15 kHz while stirring at 500 rpm for 0.5 h at 30 °C to obtain glycine derivative-activated hydromagnesite (Gly-UNHM) with a molar ratio of glycine derivative to hydromagnesite of 1 mol:10 kg. The obtained glycine derivative-activated hydromagnesite (Gly-UNHM) crude product was then subjected to suction filtration, centrifugation, precipitation, and low-temperature drying. In the suction filtration process, a rapid filter paper was used, and the vacuum degree was controlled at -0.09 MPa. The suction filtration product was repeatedly washed once with a mixed solution of methanol and twice-purified water, and the volume ratio of methanol to twice-purified water was controlled at 1:1. The suction filtration product was placed in a centrifuge and subjected to centrifugation at room temperature (25 °C). Twice-purified water was added to each centrifuge tube, and the solid content of each centrifuge tube was controlled at 1 mg / mL. The centrifugation was performed at a speed of 10000 rpm for 5 min, and the centrifugation was performed once. The centrifugation product was placed in a surface metal tray with a bottom valve and allowed to stand. An appropriate amount of a mixed solution of twice-purified water and methanol was added, and the volume ratio of methanol to twice-purified water was controlled at 1:1. The volume mass ratio of the alcohol / water mixed solution to the obtained centrifugation product was controlled at 10 mL:10 mg. The standing temperature was controlled at 1 °C, and the standing time was controlled at 1.0 h. During the precipitation process, the alcohol / water mixed solution was discharged by opening the bottom valve every 0.5 h, and then the bottom valve was closed and twice-purified water was added for further immersion. This process was repeated once. The obtained precipitation product was freeze-dried at -10 °C for 72 h to obtain glycine derivative-activated hydromagnesite (Gly-UNHM) composite powder;

[0069] (4) 402 g of nobiletin was added to methanol, and stirred at 600 rpm at 25 °C for 12 h until dissolved to obtain a solution 3 with a concentration of 1 mol / L;

[0070] (5) The glycine derivative activated hydro-magnesite (Gly-UNHM) composite powder (10 kg) was placed in a high-speed stirrer, and first pre-stirred at 1000 rpm at room temperature for 2.5 h, and then uniformly heated to 60 °C. During the heating process, the solution 3 was added to the high-speed stirrer in a spraying manner at an addition rate of 5 mL / min, and the molar amount of nobiletin was controlled to be 1 mol per 10 kg of the mass of the glycine derivative activated hydro-magnesite, until the spraying was completed. The stirring was continued for 45 min, the heating was stopped, and the temperature was cooled to room temperature, and then further reduced to low temperature stirring. The stirring was continued at 500 rpm at 1 °C for 10 min, and after the end, the precipitation was carried out at room temperature for 0.1 h. The obtained precipitate was placed in a cyclone separator, and the dust removal was carried out at a power of 200 W, a rotation speed of 1200 rpm, and a wind volume of 50 m 3 / h. The dust removal process was repeated for 3 times, and finally the flash drying was carried out at 600 W at 190 °C for 6 min to obtain a multi-methoxy flavone co-hybrid hydro-magnesite composite powder (Nob-Gly-UNHM) (the median particle size D 50 was 2.0 μm).

[0071] Example 3

[0072] (1) 1030 g of glycine derivative (N,N-dimethylglycine) was added to acetonitrile at 60 °C, and stirred at 1000 rpm for 0.5 h to obtain a solution 1 with a concentration of 10 mol / L;

[0073] (2) 10 kg of superfine high-magnesium hydro-magnesite (the median particle size D 50 was 1.8 μm) was dispersed in a methanol solution at room temperature (25 °C) and stirred at 3000 rpm for 0.5 h to obtain a dispersion 2 of superfine hydro-magnesite with a molar concentration of 10 mol / L;

[0074] (3) adding solution 1 to dispersion 2 at a rate of 30 mL / min, stirring at 2000 rpm and ultrasonicating at 80 kHz at 30°C for 1.0 h to obtain glycine derivative-activated hydromagnesite (Gly-UNHM) with a molar ratio of glycine derivative to hydromagnesite of 10 mol:10 kg, and then subjecting the obtained glycine derivative-activated hydromagnesite (Gly-UNHM) crude product to filtration, centrifugation, precipitation, and low-temperature drying in sequence, wherein the filtration is performed using rapid filter paper with a vacuum degree of -0.07 MPa, and the filtration product is repeatedly washed with a mixed solution of methanol and double-distilled water four times, with a volume ratio of methanol to double-distilled water of 10:1; the filtration product is subjected to centrifugation at room temperature (25°C) in a centrifuge, with double-distilled water added to each centrifuge tube, a solid content of 30 mg / mL in each centrifuge tube, a centrifugation speed of 1000 rpm, a centrifugation time of 45 min, and a centrifugation number of 5; the centrifugation product is placed in a surface metal tray with a bottom valve for standing, with a mixed solution of double-distilled water and methanol added thereto, a volume ratio of methanol to double-distilled water of 1:20, a volume-to-mass ratio of the mixed alcohol-water solution to the obtained centrifugation product of 30 mL:10 mg, a standing temperature of 10°C, a standing time of 36.0 h, and the bottom valve being opened every 1.5 h to release the mixed alcohol-water solution, after which the bottom valve is closed and double-distilled water is added for further immersion, and this process is repeated four times; the obtained precipitation product is freeze-dried at -30°C for 12 h to obtain glycine derivative-activated hydromagnesite (Gly-UNHM) composite powder;

[0075] (4) adding 2010 g of nobiletin to methanol, stirring at 1600 rpm at 50°C for 1 h until dissolution to obtain solution 3 with a concentration of 3 mol / L;

[0076] (5) placing the glycine derivative-activated hydromagnesite (Gly-UNHM) composite powder (10 kg) in a high-speed stirrer, pre-stirring at 6000 rpm at room temperature for 0.5 h, then uniformly increasing the temperature to 80°C, adding solution 3 to the high-speed stirrer in the form of a spray at an addition rate of 30 mL / min during the temperature increasing process, controlling the molar amount of nobiletin to the mass of glycine derivative-activated hydromagnesite to be 3 mol:10 kg, continuing to stir for 10 min after the spraying is completed, stopping heating and cooling to room temperature, further reducing the temperature to low-temperature stirring at 3000 rpm for 60 min at 10°C, and then standing at room temperature for 1.0 h for precipitation, and then placing the obtained precipitate in a cyclone separator, with a power of 800 W, a rotation speed of 3200 rpm, a volume-to-mass ratio of the obtained precipitate to the mixed alcohol-water solution of 10 mL:10 mg, and a volume ratio of the mixed alcohol-water solution to double-distilled water of 1:20, and then collecting the nobiletin-activated hydromagnesite (Nob-UNHM) composite powder in a beaker. 3 / h air flow, and repeated the dedusting process once, and finally flash dried at 220℃ for 1 min with a power of 1700W to obtain the multi-methoxy flavone co-hybrid hydromagnesite composite powder (Nob-Gly-UNHM) (median particle size D 50 was 2.0 μm).

[0077] Comparative Example 1

[0078] (1) 51.5 g of the glycine derivative was added to acetonitrile at 40℃, and stirred at 500 rpm for 1.0 h to obtain a solution 1 with a concentration of 0.5 mol / L;

[0079] The steps (2), (3), (4) and (5) were the same as in Example 1.

[0080] Comparative Example 2

[0081] (1) 1545 g of the glycine derivative was added to acetonitrile at 40℃, and stirred at 500 rpm for 1.0 h to obtain a solution 1 with a concentration of 15 mol / L;

[0082] The steps (2), (3), (4) and (5) were the same as in Example 1.

[0083] Comparative Example 3

[0084] The mechanically ground natural hydromagnesite obtained by grading was not modified and was used directly.

[0085] Application Example 1

[0086] In 100 parts by mass of natural rubber (NR), preliminary mixing was first carried out, and first, 5 parts by mass of zinc oxide, 2 parts by mass of stearic acid, 3 parts by mass of a plasticizer (paraffin wax) and 2 parts by mass of an antioxidant (4010) were added, and mixed at 145℃ for 8 min, and then discharged at 120℃. Then, 0.3 parts by mass of carbon black, 5 parts by mass of white carbon black, and 20 parts by mass of the multi-methoxy flavone co-hybrid hydromagnesite composite powder (Nob-Gly-UNHM) prepared in Example 1 were added, and mixed at 130℃ for 5 min, and then mixed at 155℃ for 7 min. Thereafter, 1.5 parts of sulfur and 2.0 parts of an accelerator (CZ and DM in a mass ratio of 3:1) were added, the nip was adjusted to 1 mm, and after 5-6 times of thin passing, the nip was adjusted to 3 mm, and discharged. After standing at room temperature for 8 h, the obtained rubber compound was vulcanized on a flat vulcanizer under the conditions of 160℃ x 6 min to obtain a natural rubber master batch, and various performance test samples were prepared using a punch press.

[0087] Application Examples 2-3 and Comparative Application Examples 1-3

[0088] The difference from the application example 1 is only that the poly-methoxy flavone co-hybridized hydromagnesite composite powder (Nob-Gly-UNHM) prepared in Example 1 is respectively replaced by the poly-methoxy flavone co-hybridized hydromagnesite composite powder (Nob-Gly-UNHM) prepared in Examples 2-3 and Comparative Examples 1-2 and the natural hydromagnesite in Comparative Example 3.

[0089] Performance test

[0090] (1) Figure 2 is a structural schematic diagram of the poly-methoxy flavone co-hybridized hydromagnesite composite powder (Nob-Gly-UNHM) prepared in Example 1. From Figure 2 It can be seen that the poly-methoxy flavone co-hybridized hydromagnesite composite powder prepared in the application has a relatively typical poly-methoxy flavone and glycine derivative functional layer, and the inner core is a natural hydromagnesite (UNMH) inorganic powder.

[0091] Figure 3 is a SEM diagram of the poly-methoxy flavone co-hybridized hydromagnesite composite powder (Nob-Gly-UNHM) prepared in Example 1. From Figure 3 It can be seen from that there is a relatively obvious wrapping material on the surface of the poly-methoxy flavone co-hybridized hydromagnesite composite powder, and the modification effect of the poly-methoxy flavone and glycine derivative functional layer is significant.

[0092] (2) The poly-methoxy flavone co-hybridized hydromagnesite composite powder (Nob-Gly-UNHM) prepared in Examples 1-3 and Comparative Examples 1-2 and the natural hydromagnesite in Comparative Example 3 are tested for activation rate and oil absorption value, and the test results are shown in Table 1:

[0093] Activation rate: the dry powder is tested by weighing method;

[0094] Oil absorption value: tested according to the standard of “General Test Methods for Pigments and Extenders Part 15: Determination of Oil Absorption” (DB / T5211.15-2014).

[0095] Table 1 Test results of activation rate and oil absorption value of the powder used in Examples 1-3 and Comparative Examples 1-3

[0096] Example Activation rate / % Oil absorption value (mL / 100g) Example 1 90.1 23 Example 2 81.3 27 Example 3 85.6 25 Comparative Example 1 48.9 34 Comparative Example 2 63.2 32 Comparative Example 3 22.8 38

[0097] As can be seen from Examples 1 to 3 and Comparative Example 3 in Table 1, after the natural hydromagnesite is modified by introducing the glycine derivative and the nobiletin, the activation rate of the composite powder is greatly increased and the oil absorption value is significantly decreased. The introduction of the glycine derivative can effectively shield the hydroxyl groups on the surface of the hydromagnesite powder, and the introduction of the nobiletin can further reduce the surface energy of the hydromagnesite, so that the surface polarity of the composite powder is reduced, which is helpful to improve the adsorption of the composite powder to the processing aid and greatly reduce the processing cost. For Comparative Examples 1 to 3, when the ratio of the added glycine derivative to the natural high-magnesium hydromagnesite is not appropriate (less than 1 mol:10 kg or more than 10 mol:10 kg), the activation rate of the obtained composite powder is increased to a certain extent, but not so significantly, and the oil absorption value is also decreased to a certain extent, but the effect is limited. This may be because when the concentration of the outer glycine derivative is not appropriate, the modification effect on the natural high-magnesium hydromagnesite is limited, and too low concentration is difficult to wrap, which also leads to the decrease of the further attachment effect of the nobiletin. On the contrary, too high concentration of the added glycine derivative will lead to the wrapping of the natural high-magnesium hydromagnesite by multiple layers or even multiple powders, resulting in the passive increase of the particle size of the natural high-magnesium hydromagnesite composite powder, further inducing the excessive hybridization and attachment of the nobiletin, and finally leading to the insignificant increase of the activation rate and the decrease of the oil absorption value of the co-hybridized composite powder. In summary, after the natural high-magnesium hydromagnesite powder is co-hybridized by adding appropriate proportions of nobiletin and glycine derivative, the comprehensive performance of the composite powder (Nob-Gly-UNHM) is significantly improved, which is beneficial to enhance the comprehensive performance of the composite powder and reduce its surface energy, so that it has good dispersibility and low polarity in the rubber matrix.

[0098] (3) The vulcanization properties of the natural rubber masterbatch prepared in Application Examples 1 to 3 and Comparative Application Examples 1 to 3 were determined according to GB / T16584-1996, and the results are shown in Table 2 below:

[0099] Table 2 Test results of the vulcanization properties of the natural rubber masterbatch obtained in Application Examples 1 to 3 and Comparative Application Examples 1 to 3

[0100]

[0101] As can be seen from the data in Table 2, in the vulcanization process of the conventional natural rubber, the vulcanization balance is generally reached with the extension of time, and the vulcanization reaction is gradually completed. In application examples 1-3, the F1 of the rubber compound gradually increases with the increase of the amount of the composite powder and the natural hydromagnesite, indicating that the increase of the amount of the composite powder and the natural hydromagnesite can improve the shear modulus and hardness. In contrast, in comparative application examples 1-2, the inappropriate proportion of glycine derivative activated hydromagnesite cannot better improve the shear modulus and hardness of the rubber compound, which may be because the internal natural hydromagnesite is not further modified, making it difficult to be compatible with the natural rubber compound, and thus difficult to be effectively dispersed between the molecular chains, resulting in poor improvement effect on the shear modulus and hardness of the rubber compound. On the other hand, with the increase of the amount of the composite powder and the natural hydromagnesite, the vulcanization time of the rubber compound tends to be shortened, indicating that it can accelerate the rate of the rubber compound to reach the vulcanization balance. However, by further comparing application examples 1-3 and comparative application example 3, the natural hydromagnesite composite powder modified by the appropriate proportion of polymethoxyflavone can shorten the time to reach the vulcanization balance to a higher degree, which may be because it can have better dispersibility in the natural rubber compound matrix and better distribution between the molecular chains to promote vulcanization, resulting in shorter time. In contrast, the inappropriate proportion of polymethoxyflavone hybrid hydromagnesite has less effect on the time to reach the vulcanization balance of the rubber compound, only slightly shortening the time, which may be closely related to the surface properties of the composite powder and its dispersibility in the matrix.

[0102] (4) The comprehensive performance of the natural rubber masterbatch prepared in application examples 1-3 and comparative application examples 1-3 was tested, and the results are shown in Table 3.

[0103] Tensile strength test: The sample polarity tensile strength was tested according to the standard of GB / T 528-2009 "Determination of Tensile Stress-Strain Properties of Vulcanized or Thermoplastic Rubber".

[0104] Tear resistance test: The test was carried out according to the requirements of GB / T 529-2008 "Determination of Tensile Stress-Strain Properties of Vulcanized or Thermoplastic Rubber".

[0105] Vertical combustion performance test: The test was carried out according to the requirements of GB / T 10707-2008 "Determination of Combustion Performance of Rubber".

[0106] Residual carbon rate test: The residual carbon mass at 800°C.

[0107] Table 3 Test results of the comprehensive performance of the natural rubber masterbatch prepared in application examples 1-3 and comparative application examples 1-3

[0108]

[0109] From the data obtained in Table 3, it can be seen that, compared with Comparative Application Examples 1-3 and Comparative Application Example 3, when the Nob-Gly-UNHM composite powder with a suitable proportion of polymethoxyflavone co-hybridized is added, the tensile strength and tear resistance of the prepared rubber composite material are significantly improved, and the limiting oxygen index (LOI) is also significantly improved. This may be because the introduction of glycine derivatives can better shield the large number of hydroxyl groups on the surface of natural hydromagnesite, so that the wubangchensu can be further hybridized, thereby effectively improving the dispersibility of the composite powder in the rubber matrix and better existing between the molecular chains. The improvement of the mechanical properties of the rubber composite material is more significant. Similarly, better dispersibility helps to improve the overall flame resistance of the composite material, more evenly plays the flame retardant effect, and improves the flame retardant efficiency. In terms of thermal performance, the introduction of glycine derivatives can also effectively improve the amount of residual carbon of the rubber composite material at high temperatures. It can be seen that the introduction of a suitable proportion of glycine derivatives and wubangchensu can significantly promote the carbon formation of the rubber composite material under ablation conditions, more effectively promote the formation of a physical barrier layer, thereby playing a solid-phase shielding effect, resisting the impact of heat flow, gas flow and mass flow, and allowing more molecular chain fragments to be fixed in the condensed phase, further strengthening the carbon layer strength. In contrast, from Comparative Application Examples 1-3, it can be seen that when the glycine derivative is introduced too low or too high, the improvement in tensile strength, tear resistance, limiting oxygen index and final residual carbon quality is not ideal. This may be because the addition of the outer layer glycine derivative is not suitable, which limits the further hybridization effect of wubangchensu, ultimately leading to poor dispersibility of the composite powder in the rubber matrix, resulting in a decrease in mechanical properties, making it difficult for the inside and outside to work together to cause a decrease in flame retardant performance, and making it difficult for the outer aromatic ring and inner MgO ceramic precursor skeleton to effectively form an integrated whole, resulting in limited increase in the final residual carbon content. In summary, by introducing a suitable proportion of glycine derivatives and wubangchensu to hybridize the hydromagnesite powder, the mechanical enhancement, tear resistance, flame retardant and carbon formation effect of natural hydromagnesite can be effectively improved. The introduction of glycine derivatives and polymethoxyflavone organic functional molecules helps to improve the multifunctionality, high added value and application range of natural inorganic mineral powder.

[0110] Although the above embodiments have made a detailed description of the present application, it is only a part of the embodiments of the present application but not all the embodiments. Other embodiments can be obtained according to the present embodiments without creativity, which are within the scope of protection of the present application.

Claims

1. A polymethoxylated flavone co-hybrid hydromagnesite composite powder, characterized in that, The compound powder comprises hydromagnesite, a glycine derivative coated on the surface of the hydromagnesite, and a polymethoxyflavone coated on the surface of the glycine derivative. The hydromagnesite and the glycine derivative are connected by an ester bond, and the polymethoxyflavone and the glycine derivative are connected by electrostatic adsorption.

2. The polymethoxyflavone co-hybrid hydromagnesite composite powder according to claim 1, characterized in that, The median particle size of the polymethoxyflavone co-hybridized hydromagnesite composite powder is 1.0-4.0 μm.

3. The polymethoxyflavone co-hybrid hydromagnesite composite powder according to claim 1, characterized in that, The median particle size of the hydromagnesite is 0.8-3.6 μm, and the total content of magnesium carbonate and magnesium hydroxide in the hydromagnesite is ≥ 90 wt%.

4. The polymethoxyflavone co-hybrid hydromagnesite composite powder according to claim 1, characterized in that, The glycine derivative is N,N-dimethylglycine, and the polymethoxyflavone is narigenin.

5. The method for preparing the polymethoxyflavone co-hybrid hydromagnesite composite powder according to any one of claims 1 to 4, characterized in that, The method comprises the following steps: Mixing a dispersion of hydromagnesite and a solution of a glycine derivative to perform an esterification reaction to obtain glycine derivative-activated hydromagnesite; Mixing the glycine derivative-activated hydromagnesite and a solution of a polymethoxyflavone to perform a hybridization treatment to obtain polymethoxyflavone co-hybridized hydromagnesite composite powder.

6. The production method according to claim 5, wherein The ratio of the amount of substance of the glycine derivative to the mass of the hydromagnesite is (1-10) mol:10 kg.

7. The preparation method according to claim 5, characterized in that The esterification reaction is performed under heating, stirring, and ultrasonic conditions; the heating temperature is 30-60 °C; the stirring rate is 500-2000 rpm; the ultrasonic power is 15-80 kHz; and the esterification reaction time is 0.2-1.0 h.

8. The preparation method according to claim 5, characterized in that The ratio of the amount of substance of the polymethoxyflavone to the mass of the glycine derivative-activated hydromagnesite is (1-5) mol:10 kg.

9. The preparation method according to claim 5, characterized in that The hybridization treatment is sequentially performed by heating and stirring and low-temperature stirring; the heating and stirring temperature is 60-100 °C, the time is 10-45 min, and the rate is 1000-6000 rpm; after the heating and stirring, the heating is stopped, the temperature is cooled to room temperature, and then the temperature is further reduced to 1-10 °C for low-temperature stirring; the low-temperature stirring rate is 500-3000 rpm, and the time is 10-60 min.

10. Use of the polymethoxyflavone co-hybridized hydromagnesite composite powder of any one of claims 1-4 or the polymethoxyflavone co-hybridized hydromagnesite composite powder prepared by the method of any one of claims 5-9 in natural rubber masterbatch.

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