Ethylene-propylene-diene monomer ( EPDM) composites filled with polyimide fibers, polysulfonamide
fibers, and Kevlar fibers were prepared by moulding method, respectively. The thermal stability of fibers, the
ablative resistance, structures of char layers, and mechanical properties of EPDM composites, and the dispersion of
fibers within EPDM were investigated. Results indicated that polyimide fibers show a better thermal stability and higher
amount of residues than Kevlar and polysulfonamide fibers. Polyimide fibers greatly improved the ablative resistance
of EPDM composites with ablative thickness of 0. 8 mm. The mechanical properties of insulations were related with the
dispersion of fibers within rubber phase influenced by the structures of fibers.