Investigation on the foaming behaviors of NC-based gun propellants

To prepare the porous NC-based (nitrocellulose-based) gun propellants, the batch foaming process of using supercritical CO₂ as the physical blowing agent is used. The solubilities of CO₂ in the single-base propellants and TEGDN (trimethyleneglycol dinitrate) propellants are measured by the gravimetric method, and SEM (scanning electron microscope) is used to observe the morphology of foamed propellants. The result shows that a large amount of CO₂ could be dissolved in NC-based propellants. The experimental results also reveal that the energetic plasticizer TEGDN exerts an important influence on the pore structure. The triaxial tensile failure mechanism for solid-state nucleation is used to explain the nucleation of NC-based propellants in the solid state. Since some specific foaming behaviors of NC-based propellants can not be explained by the failure mechanism, a solid-state nucleation mechanism which revises the triaxial tensile failure mechanism is proposed and discussed.     

聚氨酯/环氧树脂SIN中的增塑作用初探

本文通过测量聚醚氨酯(PU)/环氧树脂(EP)SIN系列的玻璃化转变温度(Tg);并对该数据进行分析及用DiBenedetto理论式对该Tg数据进行了处理,发现PU/EP SIN中,EP对PU链段存在着较强的增塑作用,这个增塑作用与PU与EP网间的互穿作用并存,它主要受PU/EP组成配比等因素的影响。