Effect of Curing Parameter on the Mechanical Properties and Bond Strength at Propellant-Liner Interfaces in Rocket Motors

Abstract

This study investigates the effect of curing parameters (Rt) on the mechanical properties and bond strength of propellants and liners in rocket motors compared to the design values. The optimal curing parameters for the propellant and liner in interface bonding were identified. Hydroxyl-terminated polybutadiene (HTPB) was used as the binder, while toluene diisocyanate (TDI) was employed as the curing agent. Various curing parameters were tested, with Rt values for the propellant (0.75 to 1.55) and liner (0.90 to 1.70). The results showed that the best mechanical properties for the liner and propellant were achieved at Rt values of 0.90 and 1.11, respectively. Subsequent interface bonding tests and analyses determined the optimal curing parameters to be 0.90 for the liner and 1.15 for the propellant. These optimal parameters resulted in a bond strength of 0.75 MPa, with the mechanical properties of the propellant and liner exceeding the required design values. The findings from this study can be utilized to enhance the manufacturing process of rocket motors and ensure their reliable performance.