2021 年 19 巻 2 号 p. 238-244
The mechanical properties of low-melting-point thermoplastic (LT) fuels can be altered by adjusting their chemical composition. This study quantitatively investigated whether LT fuels undergo changes in performance due to adjustments in their chemical composition. Tensile, adhesion, viscosity-measurement, and static-firing tests were conducted using four LT fuels. The tensile test results suggest that the xylene resin contributes to increasing the elastic modulus. The adhesive stress of xylene resin-based LT fuel endures until approximately 0.5–0.7 MPa. Xylene resin is assumed to promote urethane bonding and improve adhesion properties. The dispersion of the LT fuel regression rate is within 0.24 mm/s under all oxidizer mass flux conditions. The results of the viscosity-measurement test suggest that the viscosities of the four LT fuels are similar above 100 °C. The fuel components do not significantly affect the characteristic velocity of the fuel. These results suggest that LT fuels have twice the fuel regression rate compared with hydroxyl-terminated polybutadiene (HTPB). Therefore, an appropriate LT fuel should be selected based on its chemical components, depending on the mechanical and adhesion property required by the associated motor size.
