Abstract: Hydroxyl-Terminated-Polybutadiene Polyurethane (HTPB-PU) elastomer materials are mainly used in the “liner” layer of solid propellant rocket motor cases. The required levels of mechanical and thermal properties are obtained by reinforcing this elastomer matrix with approximately 10 wt% micron-sized carbon black (mCB) particles. Therefore, the main purpose of this study was to investigate effects of mCB alone and then when used together with 3 wt% nano-sized carbon black (nCB), micron-sized zirconia (mZrO2), nano-sized titania (nTiO2) and silica (nSiO2) on the mechanical and thermal properties of HTPB-PU elastomer matrix. The main technique used for the production of unfilled and filled HTPB-PU specimens was mechanical mixing.
Tension tests conducted at 70°C, 23°C and -40°C revealed that use of all filler combinations improved all mechanical properties of HTPB-PU elastomer matrix at all temperatures. On the other hand, compared to others, replacement of total 10 wt% mCB particles with 3 wt% nCB particles resulted in highest level of improvements. Various thermal analyses conducted for all specimen compositions indicated that use of 10 wt% total filler content had slight influences on the thermal properties of the HTPB-PU elastomer matrix.