Method of preparing polyaluminocarbosilane

Abstract

A preparation method for poly-aluminum carbon silane relates to the poly-aluminum carbon silane. The preparation method which has simple technique, low cost and is suitable for preparing the poly-aluminum carbon silane of silicon carbide ceramic matrix composites by silicone carbide fiber, silicon carbide ceramics and PIP method and a device thereof are provided. The device is provided with a container, a condenser tube, a heating jacket, a tail gas collected container and a temperature controller. The container is respectively connected with an inert gas source, the condenser tube and the temperature controller. The condenser tube is connected with a vacuum pump and is provided with an inlet and an outlet; the condenser tube is connected with the tail gas collected container which is provided with a tail gas outlet. Aluminum acetylacetonate and liquid poly carbon silicon alky are put into the container for blending and stirring; the container is arranged on the heating jacket and is connected with the device for preparing the poly-aluminum carbon silane. Vacuum-pumping is carried out; inert gas is pumped in and inert atmosphere is used for continuously replacing air for at leasttwo times; condensed water is pumped in and increased up to 300-420 DEG C from the room temperature for reaction; after the reaction is over, the cooling is carried out to room temperature, samples are taken out, and so the poly-aluminum carbon silane is obtained.

Description

technical field [0001] The invention relates to polyaluminocarbosilane, in particular to a method for preparing polyaluminocarbosilane based on liquid polycarbosilane. The polyaluminocarbosilane prepared by the method can be used as the precursor of silicon carbide ceramic matrix composite material, silicon carbide fiber and bulk silicon carbide ceramics. Background technique [0002] Polyaluminocarbosilane is an important dual-use material for military and civilian use - a good precursor of silicon carbide fiber and its ceramics. The preparation of high-performance silicon carbide fiber and its ceramics requires a good precursor material. [0003] The document "J Am.Ceram.Soc.1991, 74:1725-1728" introduced a method for preparing aluminum-containing polycarbosilane, which is to prepare aluminum-containing polycarbosilane by reacting solid-state polycarbosilane and aluminum sec-butoxide , the disadvantage of this method is that the aluminum element cannot be incorporated int...

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Problems solved by technology

[0005] As an important precursor for the preparation of silicon carbide ceramic matrix composites by PIP method - liquid polycarbosilane, at present, Grignard reaction is mainly used to synthesize hyperbranched liquid polycarbosilane from dichlorodimethylsilane (Chinese Chemical Letters, 2007, 18:754-757), although the low molecular weight hyperbranched polycarbosilane prepared by this method is easy to crosslink to obtain higher ceramic yield, but its cost is too high, and because it does not contain heterogeneous elements that can improve the high temperature performance of silicon carbide ceramics , so the temperature used is limited, so it is extremely important to obtain a low-cost liquid precursor with excellent high-temperature performance

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