Influence of Strain Rate on Mechanical Properties of HTPE/PCL Propellant Applying to Wide Temperature Range

The mechanical properties of hydroxyl-terminated polyether/poly(epsilon-caprolactone) (HTPE/PCL) propellant applying to the wide temperature range of -50 degrees C to 70 degrees C were investigated by uniaxial tensile test with different strain rates varying from 0.5 min(-1) to 10 min(-1). The scanning electron microscopy (SEM) was used to observe the fractured surface of HTPE/PCL propellant, and the dynamic mechanical analysis (DMA) was employed to analyze its strain induced crystallization at low temperature. It reveals that the temperature and strain rate have great influence on the mechanical properties of HTPE/PCL propellant. As the temperature increasing or the strain rate decreasing, the maximum tensile strength gradually reduces, but the elongation at break increases first and then decreases. The fracture of HTPE/PCL propellant changes from the part dewetting and brittle fracture at low temperature to the fracture caused by dewetting at high temperature. The master curves for mechanical properties of HTPE/PCL propellant at the wide temperature of -50 degrees C to 70 degrees C with the strain rate of 0.5 min(-1) to 10 min(-1) were obtained, the prediction of maximum tensile strength and elastic modulus can be achieved.

Automated summary

The mechanical properties of HTPE/PCL propellant are significantly influenced by temperature and strain rate, with an increase in temperature or decrease in strain rate resulting in a gradual reduction in maximum tensile strength and a peak followed by decrease in elongation at break.