Method for continuously preparing liquid polymetal carbosilane through double-circulation temperature control pipeline reactor

Abstract

The invention discloses a method for continuously preparing liquid polymetal carbosilane through a double-circulation temperature control pipeline reactor, which comprises the following steps of: mixing a material A and a material B through a mixer (1), simultaneously mixing the material A and a material C through a mixer (2), synchronously inputting two streams of mixed liquor into a circulation pipeline reactor (1), and finishing primary polycondensation in a turbulent flow state; after polycondensation, reaction liquid enters a circulating pipeline reactor (2), a material D is accurately injected through distributed feeding holes, reaction is conducted in a low-speed disturbance state, and liquid polycarbosilane is obtained. Double-reactor partition control and a temperature gradient reaction pipeline are adopted, side reaction is inhibited while polycondensation is accelerated, continuous feeding is conducted to eliminate the high-pressure risk, and the reaction efficiency is improved. And the problem of out-of-control crosslinking caused by over-high local concentration of chlorosilane is solved through distributed feeding. The oxygen content of the final product is less than 1%, the number-average molecular weight distribution range is 500-1000, the molecular weight dispersion coefficient is 1-3, and the ceramic yield is more than 60%.

Description

Technical Field

[0001] This invention belongs to the field of chemical production technology, specifically relating to a method for the continuous preparation of liquid polymetallic carbosilanes via a dual-circulation temperature-controlled pipeline reactor. Background Technology

[0002] In recent years, the requirements for materials with higher corrosion resistance and high temperature resistance have become increasingly stringent. Silicon carbide (SiC) ceramic materials, due to their excellent thermal shock resistance, chemical corrosion resistance, high-temperature oxidation resistance, high modulus, low density, and low thermal expansion coefficient, have attracted increasing attention compared to other ceramic matrix composites (Si3N4, Al2O3). The main preparation processes for SiC ceramic materials include hot pressing sintering, impregnation pyrolysis, reactive melting, chemical vapor infiltration, and combined processes such as CVI-PIP and CVI-RMI. Impregnation pyrolysis, with its relatively mild reaction conditions and simple process flow, has become the mainstream method for preparing SiC ceramic materials.

[0003] The greatest advantage of the impregnation pyrolysis method for synthesizing SiC ceramic materials lies in the fact that changing the composition and structure of the precursor can alter the composition and yield of the SiC ceramic product. Therefore, the synthesis of precursor polycarbosilanes is crucial for producing high-quality, high-yield SiC ceramics. Polycarbosilanes are mainly classified into two types: liquid hyperbranched polycarbosilanes and solid polycarbosilanes. There are numerous reports on modifying liquid polycarbosilanes by grafting different active groups to obtain products with different properties. For example, Chinese patent document CN114573821, using chloromethyltrichlorosilane and chloromethyl(methyl)dichlorosilane, magnesium as raw materials, and tetrahydrofuran and aromatic hydrocarbons as mixed solvents, yields liquid polycarbosilanes containing carbon-carbon double bonds through Grignard coupling and reduction reactions. In addition, a paper by Tian Hua Huang et al. (Chinese Chemical Letters, 2007, 18(6), 754-757) synthesized vinyl-containing hyperbranched liquid polycarbosilanes using a one-pot reaction with chloromethyltrichlorosilane, chloromethyl(methyl)dichlorosilane, and allyl chloride. All the methods reported above use a reaction vessel to prepare polycarbosilanes, which is a batch reaction with low production efficiency. Furthermore, these methods require Grignard processes or reactions under high temperature and pressure, posing a significant risk. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a method for the continuous preparation of liquid polymetallic carbon silanes via a dual-circulation temperature-controlled pipeline reactor, effectively solving the aforementioned issues.

[0005] A method for the continuous preparation of liquid polymetallic carbon silanes via a dual-circulation temperature-controlled pipeline reactor includes the following steps: Material A is an organic solution, material B is an organic solution distribution liquid of sodium metal microspheres, material C is a cyclopentadiene metal, and material D is a chlorosilane.

[0006] (1) Divide material A into two streams: the first stream is mixed with material B in mixer ①; the second stream is mixed with material C in mixer ②; (2) The two mixed liquids are simultaneously pumped into the circulating pipeline reactor ①, and the temperature is adjusted to 85-105℃ to carry out the sodium-driven dechlorination activation reaction under turbulent conditions; (3) The activation liquid is fed into the circulating pipeline reactor ②, the temperature is adjusted to 100-115℃, and the material D is continuously injected through the distributed feed holes in the pipe wall. After the feeding is completed, the temperature is adjusted to 110-120℃, and the locene metal grafting and polycondensation reaction is completed under controllable disturbance. (4) After the reaction is complete, the solution enters the intermediate tank of finished product, and the finished product solution is centrifuged, filtered and the solvent is evaporated to obtain the final product liquid polymetallic carbosilane.

[0007] The organic solution A is selected from toluene or xylene.

[0008] The organic solution distribution liquid of the material B sodium metal microspheres is selected from the toluene distribution liquid or the xylene distribution liquid of the sodium metal microspheres. Specifically, the particle size of the sodium metal microspheres is 100-500 nm, and the dispersion stability in the organic solution is >24h.

[0009] Sodium metal microspheres are obtained by high-speed stirring and shear emulsification at 3000 rpm in toluene solvent at 98-103℃. The sodium metal microspheres can be uniformly distributed in material A by ultrasonication and the addition of a stabilizer, and can be kept from agglomeration for more than 24 hours.

[0010] The material C-based metal is selected from one of zirconium dichlorodichlorodichlorodioctenoid, titanium dichlorodi ... The material D-chlorosilane is selected from one of dichlorodimethylsilane, dichloromethylethylsilane, dichloromethylphenylsilane, and dichloromethylsilane.

[0011] The mass ratio of the organic solution of the material to the organic solution distribution liquid of the sodium metal microspheres is 130:11~12, the mass ratio of the organic solution to the cyclohexane is 130:1.5~6, and the mass fraction of sodium metal in the organic solution distribution liquid of the sodium metal microspheres is 20-50%.

[0012] The organic solution and the organic solution distribution liquid of sodium metal microspheres are thoroughly mixed in mixer ①, and the organic solution and cyclohexane are thoroughly mixed in mixer ② before being transported into circulating pipeline reactor ①. The temperature of the two mixed liquids is 85-105℃ when they are simultaneously pumped into circulating pipeline reactor ①, and the temperature of the activation liquid is 100-115℃ when it is input into circulating pipeline reactor ②. After material D is fed, the temperature is adjusted to 110-120℃. The solution flow rate in circulating pipeline reactor ① is controlled at 0.01~0.15m / s, and the pipeline length is controlled at 20~50m.

[0013] The inner wall of the circulating pipeline reactor ① is equipped with baffles. The angle α between each baffle and the pipeline is 20~30°, and the spacing c between each baffle is 0.5~1.5m, so as to achieve forced turbulence and limit the Reynolds number to >4000.

[0014] With a Reynolds number in the range of 4,000-10,000, the fluid in the pipe is turbulent, ensuring rapid reaction. Under these conditions, sodium metal microspheres will not deposit in the gap between the baffle and the pipe.

[0015] The molar ratio of the metallocene to chlorosilane needs to be dynamically adjusted through distributed feeding, and the feed mass ratio is controlled as follows: metallocene: chlorosilane = 1:10~40.

[0016] The solution flow rate in the circulating pipeline reactor ② is controlled at 0.01~0.1m / s, the pipeline length is 50~150m, and the reaction time is controlled at 6~16h.

[0017] The inner wall of the internal pipe of the circulating pipeline reactor ② is equipped with baffles. The angle b between each baffle and the pipe is 10~20°, and the distance d between each baffle is 1~2m. This maintains laminar flow disturbance and is limited to a Reynolds number <2100.

[0018] When the Reynolds number is in the range of 1000-2300, the fluid state in the pipe is laminar, which ensures that the reaction proceeds completely.

[0019] The distributed feed holes are equidistantly distributed along the axial direction of the reactor ② tube wall, and the feed velocity to mainstream velocity ratio is 1:50–1:100, with the local concentration of chlorosilane being less than 5wt%.

[0020] After the reaction is completed, the resulting solution is separated from the reaction liquid by a high-speed centrifuge, and then directly enters the solvent evaporation equipment for solvent removal to obtain the final product, liquid polymetallic carbosilane.

[0021] The liquid polymetallic carbon silane prepared by the method has an oxygen content of <1%, a number-average molecular weight distribution range of 500~1000, a molecular weight dispersion coefficient of 1-3, and a ceramic yield of >60%.

[0022] The advantages of this invention compared to the prior art are: 1. Existing technologies use a batch method for preparation, and Grignard reagents require strict control of anhydrous conditions. This invention uses an organic solvent of sodium metal microspheres to replace Grignard reagents, achieving continuous reaction under mild conditions and avoiding dangerous reaction conditions such as Grignard reagents and high temperature and high pressure.

[0023] 2. A batch reactor can cause local overheating of the system, which in turn leads to cross-linking side reactions. The final product has a molecular weight dispersion coefficient >3.5 and a wide molecular weight distribution. This invention controls the feed flow rate to keep the chlorosilane concentration below 3.5wt%, thus achieving controllable molecular weight.

[0024] 3. This invention features a unique three-stage gradient temperature control design, with independent temperature control for each feeding stage. The low-temperature stage promotes the directional activation of alkali metals on cyclopentadiene metals; the medium-temperature stage promotes the vaporization of chlorosilanes, reduces local overheating, increases the reaction area, and reduces the reaction time; the high-temperature stage enhances the reaction effect, making the molecular weight distribution of the product controllable.

[0025] 3. The pipeline reactor has a special baffle structure. Compared with the circulating pipeline reactor ②, the circulating pipeline reactor ① has a smaller baffle spacing, a larger angle between the baffle and the pipeline, and a faster liquid flow rate, which can better promote the turbulent state of the solution and shorten the activation time to 40-60 min. The circulating pipeline reactor ② has a slower liquid flow rate, which can maintain a more stable flow state, suppress side reactions and ensure grafting uniformity. At the same time, the smaller angle between the baffle and the pipeline avoids the deposition of reaction solids in the pipeline wall. Attached Figure Description

[0026] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0027] Example 1 (1) The material A toluene is divided into two streams: the first stream of toluene is 130 kg, which is mixed with 12 kg of material B sodium metal microspheres in toluene distribution liquid, that is, the first stream and the toluene distribution liquid of material B sodium metal microspheres are mixed in mixer ① at a mass ratio of A:B=130:12; the second stream of toluene is 130 kg, which is mixed with 5 kg of material C zirconium dichlorodi ... (2) The two mixed liquids are simultaneously pumped into the circulating pipeline reactor ①, the temperature is adjusted to 95℃, the flow rate is controlled to 0.05m / s, the pipeline length is controlled to 20m, the internal baffle angle is controlled to 20°, the spacing between each baffle is 1m, and the Reynolds number is maintained at 8000. Under turbulent conditions, the dechlorination activation reaction driven by metallic sodium is carried out. (3) The activation liquid is fed into the circulating pipeline reactor ②, the temperature is adjusted to 105℃, and the material D dichlorodimethylsilane is continuously injected through the distributed feed holes in the pipe wall. The mass ratio of material C dichlorozirconia to material D dichlorodimethylsilane is C:D=1:10. The flow rate is controlled at 0.1m / s, the pipeline length is controlled at 50m, the reaction time is controlled at 6h, the internal baffle angle is controlled at 20°, and the distance between each baffle is 1m. After the material D is fed, the temperature is adjusted to 110℃ and the Reynolds number is maintained at 2100. The cyclopentadiene metal grafting and polycondensation reaction is completed under controllable disturbance. (4) After the reaction is complete, the solution enters the intermediate tank of finished product. The finished product solution is separated from the reaction liquid by a high-speed centrifuge and then directly enters the solvent evaporation equipment to remove the solvent toluene, and obtains liquid polyzirconium carbosilane with an oxygen content of 0.73%, a number average molecular weight of 541, a molecular weight dispersion coefficient of 1.85, and a ceramic yield of 65%.

[0028] Example 2 (1) The xylene material A is divided into two streams: the first stream contains 130 kg of xylene and is mixed with 12 kg of xylene distribution liquid of sodium metal microspheres material B (i.e., the mass ratio of A:B=130:12) in mixer ①; the second stream contains 130 kg of xylene and is mixed with 5 kg of zirconium dichlorocerocene material C (i.e., the mass ratio of A:C=130:5) in mixer ②. (2) The two mixed liquids are simultaneously pumped into the circulating pipeline reactor ①, the temperature is adjusted to 95℃, the flow rate is controlled to 0.05m / s, the pipeline length is controlled to 20m, the internal baffle angle is controlled to 20°, the spacing between each baffle is 1m, and the Reynolds number is maintained at 8000. Under turbulent conditions, the dechlorination activation reaction driven by metallic sodium is carried out. (3) The activation liquid is fed into the circulating pipeline reactor ②, the temperature is adjusted to 105℃, and the material D dichlorodimethylsilane is continuously injected through the distributed feed holes in the pipe wall. The mass ratio of material C dichlorozirconia to material D dichlorodimethylsilane is C:D=1:10. The flow rate is controlled at 0.1m / s, the pipeline length is controlled at 50m, the reaction time is controlled at 6h, the internal baffle angle is controlled at 20°, and the distance between each baffle is 1m. After the material D is fed, the temperature is adjusted to 110℃ and the Reynolds number is maintained at 2100. The cyclopentadiene metal grafting and polycondensation reaction is completed under controllable disturbance. (4) After the reaction is complete, the solution enters the intermediate tank of finished product. The finished product solution is separated from the reaction liquid by a high-speed centrifuge and then directly enters the solvent evaporation equipment to remove the solvent xylene, and obtains liquid polyzirconium carbosilane with an oxygen content of 0.77%, a number average molecular weight of 588, a molecular weight dispersion coefficient of 1.89, and a ceramic yield of 63%.

[0029] Example 3 (1) The material A toluene is divided into two streams: the first stream of toluene is 130 kg, which is mixed with 11 kg of material B sodium metal microspheres in toluene distribution liquid (i.e., the mass ratio of A:B=130:11) in mixer ①; the second stream of toluene is 130 kg, which is mixed with 1.5 kg of material C zirconium dichloroethylene (i.e., the mass ratio of A:C=130:1.5) in mixer ②; (2) The two mixed liquids are simultaneously pumped into the circulating pipeline reactor ①, the temperature is adjusted to 95℃, the flow rate is controlled to 0.1m / s, the pipeline length is controlled to 50m, the internal baffle angle is controlled to 30°, the spacing between each baffle is 0.5m, and the Reynolds number is maintained at 6800. Under turbulent conditions, the dechlorination activation reaction driven by metallic sodium is carried out. (3) The activation liquid is fed into the circulating pipeline reactor ②, the temperature is adjusted to 105℃, and the material D dichlorodimethylsilane is continuously injected through the distributed feed holes in the pipe wall. The mass ratio of material C dichlorozirconia to material D dichlorodimethylsilane is C:D=1:5. The flow rate is controlled at 0.05m / s, the pipeline length is controlled at 150m, the reaction time is controlled at 12h, the internal baffle angle is controlled at 10°, and the distance between each baffle is 2m. After the material D is fed, the temperature is adjusted to 110℃ and the Reynolds number is maintained at 1100. The cyclopentadiene metal grafting and polycondensation reaction is completed under controllable disturbance. (4) After the reaction is complete, the solution enters the intermediate tank of finished product. The finished product solution is separated from the reaction liquid by a high-speed centrifuge and then directly enters the solvent evaporation equipment to remove the solvent toluene, and obtains liquid polyzirconium carbosilane with oxygen content of 0.72%, number average molecular weight of 957, molecular weight dispersion coefficient of 1.73, and ceramic yield of 69%.

[0030] Example 4 (1) The material A toluene is divided into two streams: the first stream of toluene is 130 kg, which is mixed with 11 kg of material B sodium metal microspheres in toluene distribution liquid (i.e., the mass ratio of A:B=130:11) in mixer ①; the second stream of toluene is 130 kg, which is mixed with 1.5 kg of material C dichlorotitanium (i.e., the mass ratio of A:C=130:1.5) in mixer ②; (2) The two mixed liquids are simultaneously pumped into the circulating pipeline reactor ①, the temperature is adjusted to 95℃, the flow rate is controlled to 0.1m / s, the pipeline length is controlled to 50m, the internal baffle angle is controlled to 30°, the spacing between each baffle is 0.5m, and the Reynolds number is maintained at 6800. Under turbulent conditions, the dechlorination activation reaction driven by metallic sodium is carried out. (3) The activation liquid is fed into the circulating pipeline reactor ②, the temperature is adjusted to 105℃, and the material D dichlorodimethylsilane is continuously injected through the distributed feed holes in the pipe wall. The mass ratio of material C dichlorodicyclopentadiene to material D dichlorodimethylsilane is C:D=1:5. The flow rate is controlled at 0.05m / s, the pipeline length is controlled at 150m, the reaction time is controlled at 12h, the internal baffle angle is controlled at 10°, and the distance between each baffle is 2m. After the material D is fed, the temperature is adjusted to 110℃ and the Reynolds number is maintained at 1100. The cyclopentadiene metal grafting and polycondensation reaction is completed under controllable disturbance. (4) After the reaction is complete, the solution enters the intermediate tank of finished product. The finished product solution is separated from the reaction liquid by a high-speed centrifuge and then directly enters the solvent evaporation equipment to remove the solvent toluene, and obtains liquid polytitanium carbide with an oxygen content of 0.73%, a number average molecular weight of 924, a molecular weight dispersion coefficient of 1.75, and a ceramic yield of 68%.

[0031] Example 5 (1) The material A toluene is divided into two streams: the first stream of toluene is 130 kg, which is mixed with 11 kg of material B sodium metal microspheres in toluene distribution liquid (i.e., the mass ratio of A:B=130:11) in mixer ①; the second stream of toluene is 130 kg, which is mixed with 2 kg of material C dibutyl hafnium octene (i.e., the mass ratio of A:C=130:2) in mixer ②; (2) The two mixed liquids are simultaneously pumped into the circulating pipeline reactor ①, the temperature is adjusted to 95℃, the flow rate is controlled to 0.15m / s, the pipeline length is controlled to 50m, the internal baffle angle is controlled to 20°, the spacing between each baffle is 1m, and the Reynolds number is maintained at 5500. Under turbulent conditions, the dechlorination activation reaction driven by metallic sodium is carried out. (3) The activation liquid is fed into the circulating pipeline reactor ②, the temperature is adjusted to 105℃, and the material D dichloromethylsilane is continuously injected through the distributed feed holes in the pipe wall. The mass ratio of material C dibutyl hafnium octane to material D dichloromethylsilane is C:D=1:5. The flow rate is controlled at 0.01m / s, the pipeline length is controlled at 100m, the reaction time is controlled at 10h, the internal baffle angle is controlled at 10°, and the distance between each baffle is 2m. After the material D is fed, the temperature is adjusted to 110℃ and the Reynolds number is maintained at 1700. The locene metal grafting and polycondensation reaction is completed under controllable disturbance. (4) After the reaction is complete, the solution enters the intermediate tank of finished product. The finished product solution is separated from the reaction liquid by a high-speed centrifuge and then directly enters the solvent evaporation equipment to remove the solvent toluene, and obtains liquid polyzirconium carbosilane with oxygen content of 0.74%, number average molecular weight of 836, molecular weight dispersion coefficient of 1.81, and ceramic yield of 62%.

[0032] Comparative Example 1 While keeping other conditions unchanged in Example 1, the experiment was conducted by removing the baffle of reactor ①. The activation time was extended by 128 min, and the molecular weight dispersion coefficient increased to 3.9.

[0033] Comparative Example 2 Keeping other conditions unchanged in Example 3, except that sodium metal microspheres were replaced with sodium sand, the dispersion stability was <2h, the ceramic yield was 45%, and the pipe blockage rate was >30%.

[0034] Comparative Example 3 Keeping all other conditions unchanged from Example 3, except for replacing chlorosilane with concentrated addition, the final product crosslinked, and the experiment failed.

[0035] Comparative Example 4 Keeping all other conditions unchanged from Example 4, except that the temperature of the circulating pipeline reactors ① and ② was fixed at 110°C, the final product crosslinked, and the experiment failed.

[0036] Comparative Example 5 Keeping all other conditions unchanged in Example 4, except that the Reynolds number in step (3) is also 5500, no product was generated and the experiment failed.

[0037] Comparative Example 6 While keeping other conditions unchanged in Example 4, the Reynolds number in step (2) is also 1700, the yield of the final product is less than 10%, and its molecular weight dispersion coefficient increases to 4.6.

Claims

1. A method for continuous production of liquid polymetallo-carbosilane by a dual circulation temperature-controlled pipe reactor, characterized in that, It comprises the following steps: the material A is an organic solution, the material B is an organic solution distribution liquid of metal sodium microspheres, the material C is a metallocene, and the material D is chlorosilane; (1) The material A is divided into two routes: the first route is mixed with the material B in a mixer ①, and the second route is mixed with the material C in a mixer ②; (2) Two mixed liquids are synchronously pumped into a circulating pipeline reactor ① to perform a metal sodium driven dechlorination activation reaction under turbulent conditions; (3) After the activation liquid is input into the circulating pipeline reactor ②, the material D is continuously injected through a distributed feeding hole in the pipeline wall, and after the feeding is completed, a metallocene grafting and polycondensation reaction is completed under controllable disturbance; (4) After the reaction is completed, the solution is input into a finished product intermediate tank, the finished product solution is centrifuged and filtered, and solvent evaporation is performed to obtain a final product, liquid poly-metal-carbosilane.

2. The method for continuously preparing liquid polymetallosilane by a double circulation temperature-controlled pipeline reactor according to claim 1, characterized in that, The material A is an organic solution selected from toluene or xylene; The material B is an organic solution distribution liquid of metal sodium microspheres selected from a toluene distribution liquid of metal sodium microspheres or a xylene distribution liquid of metal sodium microspheres, the particle size of the metal sodium microspheres is 100-500 nm, and the dispersion stability in the organic solution is greater than 24 h; The material C is a metallocene selected from one of dichlorobis-cyclopentadienyl-zirconium, dichlorobis-cyclopentadienyl-titanium, dichlorobis-cyclopentadienyl-hafnium, dimethylbis-cyclopentadienyl-zirconium, dimethylbis-cyclopentadienyl-titanium, dimethylbis-cyclopentadienyl-hafnium, monochloromonohydrogenbis-cyclopentadienyl-zirconium, monochloromonohydrogenbis-cyclopentadienyl-titanium, monochloromonohydrogenbis-cyclopentadienyl-hafnium, dibutylbis-cyclopentadienyl-zirconium, dibutylbis-cyclopentadienyl-titanium, and dibutylbis-cyclopentadienyl-hafnium; The material D is chlorosilane selected from one of dichlorodimethylsilane, dichloromethyl ethyl silane, dichloromethyl phenyl silane, and dichloromethyl silane.

3. The method for continuous preparation of liquid polymeric metal carboranesilane by double circulation temperature-controlled pipeline reactor according to claim 1, characterized in that, The mass ratio of the material organic solution to the organic solution distribution liquid of metal sodium microspheres is 130:11-12, the mass ratio of the organic solution to the metallocene is 130:1.5-6, and the mass fraction of metal sodium in the organic solution distribution liquid of metal sodium microspheres is 20%-50%.

4. The method for continuous preparation of liquid polysilane metal carbosilane by double circulation temperature-controlled pipeline reactor according to claim 1, characterized in that, The organic solution and the organic solution distribution liquid of metal sodium microspheres are fully mixed by the mixer ①, the organic solution and the metallocene are fully mixed by the mixer ②, and then are delivered into the circulating pipeline reactor ①, and when the two mixed liquids are synchronously pumped into the circulating pipeline reactor ①, the temperature is 85-105℃; When the activation liquid is input into the circulating pipeline reactor ②, the temperature is 100-115℃, and after the feeding of the material D is completed, the temperature is adjusted to 110-120℃; The solution flow rate in the circulating pipeline reactor ① is controlled to be 0.01-0.15 m / s, and the pipeline length is controlled to be 20-50 m.

5. The method for continuous preparation of liquid polymeric metal carboranesilane by a double circulation temperature-controlled pipe reactor according to claim 1, characterized in that, The pipeline inner wall of the circulating pipeline reactor ① is provided with baffles, the included angle a between each baffle and the pipeline is 20-30°, and the spacing c between each baffle is 0.5-1.5 m, so that forced turbulent flow is achieved, and the Reynolds number is greater than 4000.

6. The method of claim 1, wherein the method is continuous. The molar ratio of the metallocene to the chlorosilane needs to be dynamically adjusted through distributed feeding, and the feeding mass ratio is controlled to be metallocene: chlorosilane = 1:10-40.

7. The method for continuously preparing liquid polymeric metal carboranesilane by a double circulation temperature-controlled pipeline reactor according to claim 1, characterized in that, The solution flow rate in the circulating pipeline reactor ② is controlled to be 0.01-0.1 m / s, the pipeline length is 50-150 m, and the reaction time is controlled to be 6-16 h.

8. The method for continuously preparing liquid polymeric metal carboranesilane through a double circulation temperature-controlled pipeline reactor according to claim 7, characterized in that, The inner wall of the circulating pipe reactor ② is provided with baffles, the angle b between each baffle and the pipe is 10-20°, and the distance d between each baffle is 1-2 m, so as to maintain laminar flow disturbance and limit the Reynolds number to less than 2100.

9. The method for continuously preparing liquid polymeric metal carboranesilane by a double circulation temperature-controlled pipeline reactor according to claim 1, characterized in that, The distributed feeding holes are equidistantly distributed along the axial direction of the pipe wall of the reactor ②, the feeding speed is 1:50-1:100 of the main flow speed, and the local concentration of chlorosilane is less than 5wt%.

10. A liquid polymeric metal carboranesilane prepared continuously by a dual- circulation temperature-controlled pipe reactor, characterized in that, The liquid poly-metal-carbosilane prepared by the method of any one of claims 1-9 has an oxygen content of less than 1%, a number average molecular weight distribution range of 500-1000, a molecular weight dispersion coefficient of 1-3, and a ceramic yield of more than 60%.

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