Tuning the agglomeration and combustion characteristics of aluminized propellants via a new functionalized fluoropolymer

Abstract

Fluorine-containing organic substances (FCOS) are often added to aluminized solid propellants to improve their ignition and combustion characteristics, but existing FCOS coatings tend to have poor mechanical strength, limiting their reliability in practical applications. In this experimental study, we investigate the effect of adding a new functionalized FCOS to aluminized solid propellants. Specifically we focus on the oxidation and ignition characteristics of Al-FCOS composite particles and on the combustion of fluorine-containing propellants. By altering the surface pre-ignition reaction, FCOS-modified particles are found to ignite more quickly and produce more gaseous products. For pressures above 5 MPa, adding FCOS can both increase and decrease the burning rate relative to a baseline Al propellant, depending on the precise Al-FCOS content used, with 8.5 wt% and 17 wt% Al-FCOS producing a higher and lower burning rate, respectively. Compared with the baseline Al propellant, the FCOS-modified propellants are found to produce smaller agglomerates. This shows that the ignition, combustion and agglomeration characteristics can be readily tuned by adjusting the content of the new functionalized fluoropolymer. These findings can help guide the development of FCOS additives for aluminized propellants in solid rocket motors.