Method for preparing ceramic fiber precursor

Abstract

The invention relates to a preparation method of a ceramic fibre precursor. The steps comprises that (1) the preparation of a small molecular monomer: under the oxygen-free dry atmosphere under subzero 80 DEG C to 0 DEG C, the mol ratio of boron trichloride and aliphatic secondary amine is 1 to 0.2 to 1 to 1 to 5, the boron trichloride is slowly condensed into aliphatic secondary amine triethylamine solution to react for 1 to 20 hours under magnetic force mixing and then reacts for 1 to 20 hours under the room temperature to produce yellow sedimentation for filtering; then the mol ratio of anhydrous toluene solution and aliphatic primary amine is 1 to 1 to 5 to 1, the anhydrous toluene solution is added into the filtrate by dropping to react for 1 to 20 hours under subzero 80 DEG C to 0 DEG C along with magnetic force mixing and then reacts for 5 to 30 hours under the room temperature to produce the yellow sedimentation again for filtering and reduced pressure distillation;(2) the preparation of a BN precursor: the light yellow liquid is treated for multiple-stage linear heating under magnetic force mixing, the heating speed is 0.5 to 20 DEG C per minute, the liquid is heated till 150 DEG C to 180 DEG C for 15 to 25 hours and then cooled to obtain the yellow solid precursor. The technology of the method is simple, and the continuous industrialized production can be easily realized.

Description

technical field [0001] The invention belongs to the field of polymer material preparation, and in particular relates to a preparation method of a ceramic fiber precursor. Background technique [0002] The research and development of high-performance fibers, especially high-performance inorganic ceramic fibers, has become one of the focuses of material science research in the world today. BN fiber has a variety of excellent properties, and has good composite compatibility with resins, metals, and ceramics. Boron nitride (BN) has many unique properties. It has a wide range of anti-electromagnetic radiation, low density, high temperature oxidation resistance, high heat of vaporization and excellent lubricating properties. Compared with graphite, BN has a small thermal expansion coefficient. And it can make oxide ceramics have good chemical inertness, which can be used as an ideal interface material, while BN fiber is expected to have high Young's modulus and high strength at t...

AI Technical Summary

Problems solved by technology

Over the past ten years, foreign scholars have explored various ways to prepare BN precursors. B.Bonnetot. reported in Met.Chem.1994, 17, 583-593 that BN fibers were prepared by using boron trichloride and methylamine to synthesize precursors. A new process, but the precursor synthesized by this method has a network structure and high viscosity, which is not conducive to the later spinning process

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