METHOD FOR PREPARING POLYTANNIC ACID-COATED HIGH ACTIVITY ALUMINUM POWDER OR SILICON POWDER

摘要

Disclosed is a method for preparing a polytannic acid-coated high activity aluminum powder or silicon powder. The method comprises first dissolving a buffering reagent in an organic solvent, adding tannic acid, stirring to obtain a tannic acid buffer solution, then dispersing aluminum powder or silicon powder into the tannic acid buffer solution, and stirring the mixture to allow self-polymerization to obtain the polytannic acid-coated aluminum powder or silicon powder. The method can be utilized with various sources of raw material, is environmentally friendly and safe, is simple and convenient to carry out, and is suitable for industrial production. The prepared composite material comprising aluminum or silicon and polytannic acid in a core-shell structure can effectively prevent rapid oxidation on aluminum or silicon particle surfaces, thus protecting the activity of aluminum or silicon powder. The composite material comprising aluminum or silicon and polytannic acid in a core-shell structure can be added to a solid propellant, and due to the rich carbon content, upon high temperature combustion, the coated polytannic acid can provide additional heat of combustion and promote fast combustion of the aluminum powder or silicon powder, thus enhancing the combustion performance of the solid propellant.