Studies on rheological properties of gelled propellant based on new energetic cellulose

The nitromethane (NM) gels was prepared with carboxymethyl cellulose nitrate (CMCN) as a gelator. The law of different rheological properties of NM/CMCN gels caused by the proportional change of modified group on CMCN was investigated. The yield stress, thixotropy, creep and thermosensitivity of NM/CMCN gels were investigated by linear rheological methods and the gel mechanism was discussed. The flow data, creep data, angular frequency data and thermosensitivity data of gels were fitted by Herschel-Bulkley model, Burger model, Carreau-Yasuda model and Andrade-Eyring model respectively. The experimental results show that NM/CMCN gel is a physical gel with a crosslinking network structure which is formed by non-covalent interaction of hydrophobic bonds and interchain hydrogen bonds between amphiphilic group along the macromolecular chain of CMCN and small organic molecules. The non-Newton coefficient n of CMCN gels are all less than 0.60. With the decrease of the content of nitrate group, structure strength of NM/CMCN gels become weaker, therefore, the yield stress decrease while thixotropy recovery increase gradually, the viscous compliance and elastic compliance of gel decrease while the proportion of viscous compliance increase. The elastic responsivity decreases while viscous responsivity increase, and the internal friction increases gradually. The activation energy of NM/CMCN gels increase from the global aspect and temperature stability become weaker with the decrease of the content of nitrate group.