HfC/C ceramic precursor polymer and preparation method thereof

A technology of polymers and compounds, applied in the field of polymer materials, can solve problems such as structural characterization of side reactions that cannot be ruled out, few researches on the conversion of hafnium carbide ceramics, and complex reaction processes, etc., to achieve low oxygen content, reduce weight loss, and ensure solubility. Effect

Active Publication Date: 2020-12-25
INST OF CHEM CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

For hafnium-containing polymer systems, bifunctional monomers can be used for polymerization, such as diols or diacids reacted with hafnium compounds to construct hafnium oxide polymers, or double carbanogens and dichlorohafnocenes to synthesize hafnium carbon polymers, However, most of the products obtained from these systems are insoluble products, and side reactions cannot be ruled out and structural characterizations are performed. The cracked products often contain hafnium oxide.
In addition, hafnium n-butoxide and hafnium dimethylamino hafnium are used to modify silicon-based polymers, and after cracking, a special structure product with metal components dispersed in silicon-based ceramics is produced. The metal content of this type of system is very low and the same The reaction process is complicated
Soluble hafnium polymers with a clear coordination structure have not been reported so far, and there are few related studies on the transformation of hafnium carbide ceramics

Method used

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  • HfC/C ceramic precursor polymer and preparation method thereof
  • HfC/C ceramic precursor polymer and preparation method thereof
  • HfC/C ceramic precursor polymer and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0055] Add 2.0mmol of hafnium tetra-n-propoxide, 2.0mmol of tetrasalicylidene-3,3'-diaminobenzidine, and 20mL of N-methylpyrrolidone into a 100mL single-necked flask, and stir at 25°C for ligand exchange polymerization After reacting for 4 hours, the reaction mixture was added to 120 mL of methanol, and a yellow solid was precipitated. After filtration, the precursor polymer represented by formula I provided by the present invention was obtained.

[0056] Its H NMR and C NMR spectra are as follows figure 1 with figure 2 As can be seen from the figure, the product has a correct structure and is the target product.

[0057] GPC characterization number average molecular weight is 3750 (n is 4.7 among the corresponding formula I), and GPC spectrogram is as image 3 shown.

[0058] The precursor polymer was pyrolyzed at 1600°C for 2 hours in an argon atmosphere to obtain a black ceramic product with a ceramic yield of 59.4%. XRD and Raman spectrum analysis showed that the produ...

Embodiment 2

[0062] 100mL one-necked flask, add 1.0mmol of hafnium tetra-n-propoxide and 1.0mmol of hafnium tetraisopropoxide, 2.0mmol of tetrasalicylidene-3,3'-diaminobenzidine, 10mL of N-methylpyrrolidone and 10 mL of tetrahydrofuran was stirred at 25°C for ligand exchange polymerization for 24 hours, then the reaction mixture was added to 120 mL of methanol, a yellow solid was precipitated, and the precursor polymer represented by formula I provided by the present invention was obtained after filtration.

[0063] GPC characterization number average molecular weight is 4100 (n is 5.1 in the corresponding formula I).

[0064] The precursor polymer was pyrolyzed at 1600°C for 2 hours in an argon atmosphere to obtain a black ceramic product with a ceramic yield of 61.9%. XRD and Raman spectroscopic analysis showed that the product was HfC / C ceramics.

[0065] The ultra-high temperature performance of the HfC / C ceramic product cannot be detected in a general laboratory because it cannot be m...

Embodiment 3

[0068] In a 100mL one-necked flask, add 2.0mmol of hafnium tetra-n-butoxide and 3.0mmol of tetrasalicylidene-3,3'-diaminobenzidine, 10mL of dimethylformamide and 10mL of tetrahydrofuran, and stir at 40°C Ligand exchange polymerization was carried out for 6 hours, and then the reaction mixture was added to 60 mL of methanol and 60 mL of ethanol, a yellow solid was precipitated, and after filtration, the precursor polymer represented by formula I provided by the present invention was obtained.

[0069] According to GPC, the number average molecular weight is 2460 (n is 3.1 in the corresponding formula I).

[0070] The precursor polymer was pyrolyzed at 1600°C for 2 hours in an argon atmosphere to obtain a black ceramic product with a ceramic yield of 57.3%. XRD and Raman spectroscopic analysis showed that the product was HfC / C ceramics.

[0071] The ultra-high temperature performance of the HfC / C ceramic product cannot be detected in a general laboratory because it cannot be mel...

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Abstract

The invention discloses an HfC / C ceramic precursor polymer material and a preparation method thereof. The polymer has a coordination structure of hafnium and tetramine tetraphenol, and can be pyrolyzed and converted into HfC / C ceramic at the temperature of 1600 DEG C or above, and the ceramic yield is not lower than 55 wt%. The preparation method of the polymer is characterized in that a hafnium source compound and a tetraimine tetraphenol monomer are subjected to a one-pot polymerization reaction to synthesize the polymer. The polymer precursor prepared by the method is expected to be used asa dipping matrix of a ceramic matrix composite material and an antioxidant carbon / carbon composite material so as to improve the ultrahigh-temperature oxidation resistance of the ceramic matrix composite material and the antioxidant carbon / carbon composite material.

Description

technical field [0001] The invention belongs to the field of polymer materials, and in particular relates to a HfC / C ceramic precursor polymer and a preparation method thereof. Background technique [0002] Ultra-high-temperature ceramics mainly composed of refractory metal carbides can maintain relatively stable physical and chemical properties under extreme conditions such as high-temperature environments and reactive atmospheres, and can be used in thermal protection parts of aircraft to improve the oxidation resistance of carbon / carbon composites and ablation resistance properties. Hafnium carbide has excellent physical and chemical properties, such as ultra-high melting point, high hardness, wear resistance, good electrical and thermal conductivity, and chemical stability, so it has become one of the most concerned ultra-high temperature ceramic materials. The traditional synthesis methods of hafnium carbide include solid-state elemental combustion, carbon thermal redu...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08G83/00C04B35/56C04B35/524C04B35/622
CPCC04B35/524C04B35/5622C04B35/622C08G83/008
Inventor 吴雨桓赵彤叶丽韩伟健
Owner INST OF CHEM CHINESE ACAD OF SCI
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