This study examined addition of polymeric fuel powder to hybrid rocket fuel to improve its mechanical properties. Microcrystalline wax is attractive as a hybrid rocket fuel: its regression rate is about 2—4 times higher than that of hydroxyl-terminated polybutadiene (HTPB). Unfortunately, cracks in fuel grains are caused and promoted by the low tensile strength of microcrystalline wax. Therefore, to improve the microcrystalline wax tensile strength, we added polymethyl methacrylate (PMMA) powder. We conducted experiments to ascertain the tensile strength and ignitibility while observing effects of PMMA powder added to microcrystalline wax. Results demonstrated that increasing the added amount increases tensile strength and decreases ignitibility.
hybrid rocket, ignitibility, microcrystalline wax, PMMA powder, tensile strength