Investigation of the Redox Property, Migration and Catalytic Performance of Ferrocene-Modified Hyperbranched Poly(amine) Ester

The electrochemical properties of a series of ferrocene modified hyperbranched poly(amine) esters (HPAE-Fc) were analyzed by cyclic voltammetry. HPAE-Fc was used as burn-rate catalytic components added into hydroxyl-terminated polybutadiene (HTPB)-based elastomers to simulate the original migration process in propellants to investigate the migration behavior of HPAE-Fc. The ultraviolet absorption properties of HPAE-Fc and their migration inhibition effects in HTPB elastomers under different aging conditions were analyzed. The diffusion coefficients (D) of the migration components were calculated according to Fick's law. The catalytic performance of HPAE-Fc for thermal decomposition of hydroxyl-terminated polybutadiene was also investigated by non-isothermal measurement using the Ozawa method. HPAE-Fc maintains the special redox properties by electron transfer of ferrocene/ferrocenium in ferrocene groups; and, all the redox centers were equivalent with no interaction between them. The migration of HPAE-Fc in HTPB was minimized significantly by grafting ferrocenes onto the hyperbranched structures compared with that of simple ferrocene derivatives-ferrocenecarboxylic acid and tert-butylferrocene. HPAE-Fcs present efficient catalytic effects on the thermal degradation of HTPB; and, the catalytic reactions were characterized by decreased activation energy and increased rate constant.