Progress on the synthesis and catalytic and anti-migration properties of ferrocene-based burning rate catalysts

Burning rate catalysts are of great importance in solid composite propellants for their unique property of accelerating combustion speed. Among various kinds of burning rate catalysts, ferrocene and its derivatives exhibit excellent catalytic effects and have become the most widely used burning rate catalysts. However, these simple ferrocenyl compounds trend to migrate in solid composite propellants during storage, which causes great damage to the propellants, equipment and environment and can even affect personal safety. The exploration of novel anti-migratory ferrocene-based compounds has become an advanced research hotspot in the field of burning rate catalysis. This review focuses on recent progress on the synthesis and catalytic properties of ferrocene-based polymers and ferrocene derivatives as burning rate catalysts. Two main aspects of anti-migratory exploration, i.e. synthesis of ferrocene-based polymers and modification of the side groups of ferrocene, are summarized. Ferrocene-based polymers can be obtained via condensation polymerization, addition polymerization, ring-opening polymerization, polymer reactions, etc. Ferrocenyl compounds with active groups and ferrocene-based metal coordination compounds were developed instead of the methods of lengthening the carbon chain of side groups and improving molecular polarity. Also, possible mechanisms of burning rate catalytic activity and migration are discussed and analyzed. Finally, the key points of the development of ferrocene-based burning rate catalysts and solid composite propellants are proposed. Copyright © 2016 John Wiley & Sons, Ltd.