Research on relationship between macroscopic and microscopic properties of aging HTPB coating

To study the relationship between macroscopic and microscopic properties of aging hydroxyl-terminated polybutadiene (HTPB), the accelerated aging experiments under 323.15K, 333.15K and 343.15K were carried out. The maximum elongation was tested by uniaxial tension, and the crosslink density was obtained by nuclear magnetic resonance(NMR) test. The maximum elongation is the representation of macroscopic character, while the crosslink density is used to describe the microscopic properties. The results show that, there is a good correlation between maximum elongation and crosslink density, by which the maximum elongation can be predicted according to the NMR test result.