NC/DIANP共混体系的宏微观力学性能

In order to explore inherent factors that determine the mechanical properties of nitrocellulose/1, 5-diazido-3-nitrazapentane (NC/DIANP) blend, the dynamic and static mechanical properties of NC/DIANP and nitrocellulose/nitroglycerine (NC/NG) blends were investigated by dynamic mechanical analysis and uniaxial tension test. The models of NC/DIANP and NC/NG blends were built, and the mechanism in change of mechanical properties was further evaluated by using molecular dynamics simulation. The results show that when replacing NC with DIANP, the free volume increases, both hydrogen bond and Van der waals force of NC decrease, and the mobility of NC molecular chains strengthen, which makes the α-transition peak temperature decrease from 75.6 to 53.5℃ and the mechanical loss peak value increase from 0.567 to 0.778, the β-transition peak temperature decrease from -23.7 to -25.0℃ and the mechanical loss peak value increase from 0.126 to 0.127. Meantime, the maximum tensile strength decrease from 15.31, 12.11 and 5.13MPa to 14.24, 10.08 and 1.90MPa with maximum elongation rate increase from 1.78%, 8.08%, 36.01% to 2.91%, 24.56%, 61.51% at -40, 20 and 50℃, respectively.