A method for radiation reduction and curing of liquid polycarbosilane

Abstract

The invention provides a method for radiation reduction and solidification of liquid polycarbosilane, which belongs to the field of macromolecules and the field of inorganic non-metallic ceramics. The invention applies the electron beam radiation technology to the reduction and curing of liquid polycarbosilane, under the electron beam radiation, the liquid polycarbosilane containing chloromethyl groups undergoes a radiation chemical reaction, and the liquid polycarbosilane is realized while chlorine atoms are reduced by hydrogen. Cross-linking and curing of carbosilane, this method can be directly applied to the preparation of silicon carbide ceramic-based materials by impregnation pyrolysis of liquid polycarbosilane, without introducing unsaturated bonds into the molecular chain of liquid polycarbosilane, or in the liquid polycarbosilane precursor The curing of liquid polycarbosilane can be realized by adding crosslinking agent, catalyst and initiator, which not only avoids the change of the silicon-carbon ratio of the polymer precursor during the curing process, but also avoids the introduction of heteroatoms such as platinum, oxygen and nitrogen. , has the advantages of simple operation, easy control, and large-scale production.

Description

A kind of method for radiation reduction and curing of liquid polycarbosilane technical field The invention belongs to polymer field and inorganic non-metallic ceramic technical field, relate to a kind of liquid polycarbosilane Methods of radiation reduction and curing. Background technique Silicon carbide (SiC) is an advanced ceramic material that has received extensive attention, with high strength, low density, high resistance High temperature, anti-oxidation, good compatibility with metals, etc., in the fields of aviation, aerospace, weapons and equipment and civil high temperature resistant parts Has broad application prospects. Among the developed SiC ceramic preparation methods, the polymer impregnation pyrolysis method (PIP) has It has the characteristics of easy molding and processing of polymers, and has become the most suitable for the preparation of SiC films, SiC continuous fibers, SiC matrix composites and adhesives. The most efficient method for com...

AI Technical Summary

Problems solved by technology

However, these methods also deviate the silicon-carbon ratio of the cured polymer from 1:1, and introduce a certain amount of free carbon and SiO in the final ceramic product. 2 Such impurities seriously affect the performance of the product

[0005] (2) The hydrogenation reduction reaction of liquid polycarbosilane was not complete during the preparation process, and part of the methyl chloride could not be completely reduced

It can be seen that although the hydrogenation reduction of methyl chloride is not complete, it will not affect the composition of the final product, but it will also reduce the ceramicization rate of the liquid polycarbosilane prepared by the Grignard coupling method.

In the reported studies on the pyrolytic ceramicization of liquid polycarbosilane, no further reduction treatment of methyl chloride has been found, and an effective way to completely remove the methyl chloride contained in liquid polycarbosilane has not yet been found.

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