Synthesis of ferrocenyl functionalized hyperbranched polyethylene and its application as low migration burning rate catalyst

Ferrocene based burning rate catalysts (BRCs) play an important role in the solid rocket propellants. However, the migration problem during curing and storage limits their application in the solid rocket propellants. To tackle this problem, the ferrocenyl functionalized hyperbranched polyethylene (HBPE- g -PFcEMA) with high molecular weight was synthesized as low migration BRCs. HBPE- g -PFcEMA was characterized by 1 H NMR, FT-IR, GPC and XPS . The electrochemical properties of HBPE- g -PFcEMA were evaluated by cyclic voltammetry . TGA results revealed that the HBPE- g -PFcEMA was quite stable under 210 °C. The catalytic efficiency of HBPE- g -PFcEMA for thermal decomposition of ammonium perchlorate (AP) was evaluated by TGA method. When 17 wt% of HBPE- g -PFcEMA was added, the final decomposition temperature of AP was decreased dramatically from 417 °C to 339 °C and the maximum weight loss temperature of AP was decreased from 408 °C to 328 °C. The migration property of HBPE- g -PFcEMA was studied and compared with ferrocene. Ferrocene migrated out of the migration tube after 6 days storage while the HBPE- g -PFcEMA only showed little migration even after 31 days storage at 50 °C. Therefore, the HBPE- g -PFcEMA was a low migration BRC with high catalytic efficiency for thermal decomposition of AP, which might find its application in aerospace.