Correlation between macroscopic microscopic aging properties and lifetime prediction of hydroxyl-terminated polybutadiene inhibitor

To study the correlation between the macroscopic and microscopic properties of the hydroxyl-terminated polybutadiene inhibitor in solid rocket motor, as well as accurately predict the storage life of the material, accelerated aging tests at 50℃, 60℃, 70℃ and 80℃ were carried out. The correlation functions about crosslink density and maximum elongation were built, and logarithmic model, power function model and exponential model were used to study how the crosslink density varied with storage time. The crosslink density was selected to describe the aging properties, and the modified Arrhenius method was chosen to predict the storage life of hydroxyl-terminated polybutadiene inhibitor under room temperature. The results show that the power function model with α=0.3 can describe the variation law of crosslink density well. The apparent activation energy of the aging reaction obtained by modified Arrhenius method has a linear relationship with temperature. Taking the crosslink densities as the failure criterion, which are calculated by linear equation and quadratic polynomial respectively when the maximum elongation decrease of 50%, the estimated storage lifetime of the hydroxyl-terminated polybutadiene inhibitor at 298.15 K are 17.38 years and 16.14 years, identical to that when solved with the maximum elongation. Besides, the predicted lifetime can meet the aging performance requirements of the inhibitor.