A kind of method for preparing Si-C-O ceramic fiber by conversion of organosilicon resin

Abstract

The invention provides a method for converting organic silicon resin to prepare a Si-C-O ceramic fiber. The non-melting of a silicon resin fibril is completed by adopting ultraviolet radiation cross-linking or reactive atmosphere cross-linking; afterwards, the Si-C-O ceramic fiber is prepared through high-temperature sintering. The ultraviolet radiation is used for realizing the cross-linking process of the fibril through enabling the molecule of the organic silicon resin to generate a free radical; a reactive atmosphere is used for realizing cross-linking through reacting with Si-OH; thus, the non-melting process of the fiber is completed; a non-melting and further insoluble three-dimensional network structure is formed; the fibril is enabled to be incapable of generating melting and doubling in a subsequent high-temperature pyrolysis process. The method can be used for reducing the production cost of the Si-C-O ceramic fiber, and the obtained Si-C-O ceramic fiber is enabled to have better mechanical performance.

Description

technical field [0001] The invention belongs to the field of precursor conversion ceramics, and in particular relates to a method for preparing Si-C-O ceramic fibers by conversion of organic silicon resin. Background technique [0002] SiC fiber has excellent high temperature resistance and mechanical properties, and has good compatibility with metals, ceramics, and polymers. It is an ideal inorganic reinforcing fiber and has broad applications in high-tech fields such as aerospace, weaponry, and nuclear industry. However, the high price of SiC fiber is one of the most important reasons that limit the further expansion of its application field. Oxygen-containing SiC fiber, that is, Si-C-O fiber, has good performance at 1200 ° C. Compared with oxide fiber, it has better temperature resistance and acid and alkali corrosion resistance. Compared with SiC fiber, it has the advantage of low preparation cost. , has received more and more attention from researchers in recent years....

AI Technical Summary

Problems solved by technology

[0003] Commonly used methods in the prior art for preparing Si-C-O fibers include: 1) Utilize the conversion of phenyl and propyl silicone resins to prepare ceramic fibers and composite materials. Mixing, the precursor is melt-spun to obtain silicone resin fibrils, and the Si-C-O fiber is prepared by using the non-melting process of ultraviolet radiation + thermal crosslinking. There is obvious two-phase separation in the internal structure of the fiber, resulting in a loose fiber structure and basically no Performance

2) Using the YR3370 silicone resin produced by Momentive Corporation of Japan as a precursor, the fibrils were prepared by melt spinning, and Si-C-O fibers with low carbon content were prepared by atmosphere non-melting, and the non-melting and fiber properties of the fibers were studied under different atmospheres. Oxidation resistance, because the prepared fibers contain more holes and defects, and the carbon content is low, resulting in Si-C-O fibers mainly composed of SiO 2 Composed of free carbon and poor mechanical properties

[0004] Silicone resin is now used to prepare Si-C-O ceramic fibers. The obtained fiber filaments have a large amount of pores, or there is obvious two-phase separation, or the carbon content is low, resulting in poor mechanical properties of the fibers, which are far from meeting the requirements of Si. -C-O ceramic fiber requirements

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