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

• Published in: Propellants, explosives, pyrotechnics Vol. 46; no. 4; pp. 618 - 625
• Main Authors: Yuan, Shen, Zhang, Bowen, Wen, Xiaomu, Chen, Keke, Jiang, Shengkun, Luo, Yunjun
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.04.2021
• Subjects: Crystallization; Drying; Dynamic mechanical analysis; Elongation; High temperature; HTPE/PCL propellant; Low temperature; Master curve; Mechanical properties; Modulus of elasticity; Strain analysis; Strain rate; Tensile strength; Tensile tests; Wide temperature range
• ISSN: 0721-3115; 1521-4087
• DOI: 10.1002/prep.202000238

The mechanical properties of hydroxyl‐terminated polyether/poly(ϵ‐caprolactone) (HTPE/PCL) propellant applying to the wide temperature range of −50 °C to 70 °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 °C to 70 °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.