Method for preparing borosilazane ceramic fiber precursor

The technology of ceramic fiber and silaborazane is applied in the field of preparation of silaborazane ceramic fiber, which can solve the problems of limited research and application of wave-transmitting materials, and achieve the effects of excellent mechanical properties, high synthesis yield and simple preparation.

Inactive Publication Date: 2010-12-15
DONGHUA UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, this method mainly prepares SiBNC ceramic fibers with Si-C-B connection structure, because the ceramic fibers con

Method used

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  • Method for preparing borosilazane ceramic fiber precursor
  • Method for preparing borosilazane ceramic fiber precursor
  • Method for preparing borosilazane ceramic fiber precursor

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037](1) Set up the rectification device. The temperature rises above the boiling point of the toluene solvent, about 120°C. Solvent toluene flows in the solvent distillation head along airflow and reflux condenser, and the solvent toluene water content that distills out is about 5ppm; (2) as figure 1 As shown, take 200ml of distilled toluene, according to figure 1 Set up the device, vacuumize the whole device repeatedly, pass dry nitrogen three to four times, remove the air and moisture, and then place the single-necked flask in the cooling system to condense to -80 ° C ~ -40 ° C and keep it for 1 hour (3) Mix methylamine solution and toluene with a volume ratio of 1:1, and let stand for 1 hour; (4) Clamp one end of the three-way pipe connected to the methylamine steel cylinder with surgical forceps, and change this end to lead to boron trichloride (BCl 3 )gas. Then repeatedly evacuate the whole set of equipment and pass dry nitrogen three to four times to ensure that ...

Embodiment 2

[0039] (1) the solvent toluene water content that distills out by embodiment 1 is about 5ppm; (2) as figure 2 As shown, take a certain amount of distilled toluene and put it into a three-necked flask, according to figure 2 Set up the device, vacuumize the whole device repeatedly, pass dry nitrogen three to four times, remove the air and moisture, and then place the single-necked flask in the cooling system to condense to -80 ° C ~ -40 ° C and keep it for 1 hour (3) Mix methylamine solution and toluene with a volume ratio of 1:1, and let stand for 1 hour; (4) Clamp the end of the three-way pipe connected to the methylamine cylinder with surgical forceps, then repeatedly vacuumize and dry the whole set of devices Nitrogen three to four times to ensure that the whole set of equipment is a vacuum environment; (5) take 48.7ml of SiCl with a syringe 4 The liquid (0.42mol) is injected into the mixed solution of methylamine and toluene, and white smoke is generated. At this time, i...

Embodiment 3

[0041] (1) Place the three-neck flask, hollow stopper, air guide plug, funnel, 50ml measuring cylinder, and electronic scale in the glove box to repeatedly vacuumize and replace with nitrogen gas for 2 to 3 times, according to the B(NHCH synthesized in Example 1) 3 ) 3 Small molecule 0.42mol, Si(NHCH synthesized in embodiment 2 3 ) 4 The small molecule is 1.26mol, and the two small molecules are mixed evenly and then transferred to a three-necked flask; (2) After setting up the co-condensation reaction device, use surgical forceps to clamp the wax-sealed end, repeat vacuuming, and Ar 2 After 2-3 replacements, start to rise from room temperature to 100°C at a rate of 10°C / min, and then keep it for 1 hour, then linearly raise the temperature to 120°C at the same rate, keep it for 2 hours, and stir vigorously. After the toluene is completely evaporated, Raise the temperature to 135-165°C; (3) After 12 hours of reaction, the solution begins to turn into a light yellow liquid wit...

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Abstract

The invention relates to a method for preparing a borosilazane ceramic fiber precursor, which comprises the following steps of: reacting boron trichloride (BC13) with methylamine (CH3NH2) at -80DEG C for 12 to18 hours, reacting at -40 DEG C for 12 to 18 hours to synthesize B(NHCH3)3 micromolecules, and synthesizing Si(NHCH3)4 micromolecules by silicon tetrachloride (SiCl4) and the methylamine (CH3NH2); and removing excessive methylamine from the two type of micromolecules, filtering, mixing, condensing at the temperature of between 135 and 165 DEG C to obtain the precursor with good filament picking effect. The method has the advantages of low cost of raw materials, pure product, and high synthetic yield; and the prepared ceramic fiber precursor is heated to 1,700 DEG C in the ammonia atmosphere, the obtained product has the carbon content of less than 0.05 percent through element analysis, and has good wave permeability and good application prospect.

Description

technical field [0001] The invention belongs to the field of preparation of silicon boron nitrogen ceramic fibers, in particular to a preparation method of a silicon borazane ceramic fiber precursor. Background technique [0002] Silicon-boron-nitrogen multi-element ceramic system and Si 3 N 4 Compared with binary ceramic systems such as BN, it has more excellent high temperature resistance and is a new type of ceramic material that is favored. In addition, by adjusting the element composition in silicon boron nitrogen ceramics, its wave-transmitting performance can be improved, and it has broad application prospects in high-tech fields such as aerospace. [0003] Among the silicon-boron-nitrogen ceramic fibers, most of the SiBNC ceramic fibers are now prepared. The preparation of silicon-boron-nitrogen ceramic fibers mainly adopts the precursor conversion method. The precursor conversion method can be mainly divided into two types according to the precursor synthesis rou...

Claims

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Application Information

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IPC IPC(8): C04B35/58C04B35/622
Inventor 余木火袁佳韩克清赵曦彭雨晴王征辉潘礼存邓智华徐晓倩田银彩
Owner DONGHUA UNIV
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