Method for preparing polymerized boron silazane precursor

Abstract

The process of preparing polyborosilazane precursor with boroalkyl halide, silane halide and alkyl amine as initial material includes the following steps: mixing boroalkyl halide and silane halide in the molar ratio of 0.1-10 and alkyl amine in excessive amount to react; filtering the product to obtain filtrate as low molecular borosilazane; heating the low molecular borosilazane to polymerize and cooling to obtain polyborosilazane precursor. The polyborosilazane precursor has cheap material, simple reaction process, high yield, homogeneous element distribution in atom level, and effectively controlled machining performance and physical performance.

Description

technical field

[0001] The invention relates to a preparation method of a polyborosilazane precursor. Background technique

[0002] Multi-component ceramics containing Si, B, N, C and other elements have excellent high-temperature strength, high modulus, excellent high-temperature oxidation resistance and high-temperature creep resistance. Therefore, Si-B-N-C system ceramics are used in aviation, aerospace, weapons, Ships and other fields that require high strength, high modulus, high temperature resistance, oxidation resistance, thermal shock resistance, and high temperature creep resistance materials have important application prospects.

[0003] Precursor conversion method is an effective way to prepare such ceramic materials. At present, the preparation methods of Si-B-N-C ceramic precursors mainly include polymer route and monomer route.

[0004] The polymer route refers to modifying Si-N bond-containing polymers such as polysilazane with boron-containing compounds to...

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