HfC/C ceramic precursor polymer and preparation method thereof

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...

Examples

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...

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...

Examples

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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