Room-temperature curing agent, preparation method and application of a high-temperature-resistant organic silicon material

Abstract

The invention provides a room temperature curing agent for high-temperature-resistant organosilicon materials, a preparation method and applications thereof. The room temperature curing agent comprises polysilazane and a catalyst, wherein the molecular structure of the polysilazane is optimized, and only contains difunctional Si-N chain segments and trifunctional Si-N chain segments, and the random branched structure is formed by a polymerization reaction; by adjusting the feeding ratio, pressurizing during the aminolysis and using ceramic ball-assisted mass transfer, the use amounts of the trifunctional silane and the ammonia gas for forming the trifunctional Si-N chain segment with the same content are substantially reduced, the molecular structure of the polysilazane is optimized, the generation of ammonium chloride is reduced, and the mass transfer and heat transfer control during the aminolysis is easily achieved; and the optimization does not affect the formation of the cross-linked network of the cured organosilicon material, and the structure optimizing meets the development trend of green chemistry.

Description

technical field [0001] The invention relates to a room-temperature curing agent for a high-temperature-resistant organic silicon material, a preparation method and an application thereof, and belongs to the field of high-temperature-resistant materials and their preparation. Background technique [0002] With the rapid development of modern aerospace requirements, the flight speed of the required aircraft is getting faster and faster, which makes the temperature of the aircraft face higher and higher, which puts forward higher and higher requirements for high temperature resistant protective materials, such as Room temperature curing, high temperature resistance, high mechanical properties of protective materials. Because of its good heat resistance, cold resistance, weather resistance, aging resistance and other characteristics, silicone materials are widely used as material substrates resistant to high temperatures of 250 ° C, but at higher operating temperatures above 350...

AI Technical Summary

Problems solved by technology

The commonly used method at present is to introduce large-volume anti-degradation components into the molecular weight structure of organic silicon, such as cyclodisilazane, carborane, etc., while effectively improving the temperature resistance of organic silicon materials, it greatly increases The cost of materials; another method is to add a large amount of heat-resistant inorganic fillers, which can effectively improve the temperature resistance of organic silicon materials and often lead to poor processability, which limits the application of materials

[0003] Existing silicone protective materials usually need to be cured at high temperature, and the curing temperature is generally above 150°C, which is inconvenient for construction and consumes a lot of energy, which is not conducive to industrial application and promotion

In addition, at present, chlorosilanes are mostly used to directly pass ammonia gas to prepare polysilazane curing agents. The contact probability of the reaction raw materials is small, and the ammonium chloride generated during the reaction will coat the reaction raw materials. The utilization rate of raw materials is insufficient, and the reaction process is difficult to control. , the product structure is unstable; and because the ammonolysis rate of multifunctional chlorosilanes is often much higher than that of difunctional chlorosilanes, it is easy to have too many multifunctional structures such as trifunctionality in the product, the viscosity of the curing agent is large, and the cured organic Silicon material is too hard to meet the needs of practical applications

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