Denitration and nano-ZnO loading strategy to enhance thermal conductivity and ablation inhibition of nitrocellulose

The introduction of deterring agents in the surface layer of nitrocellulose-based gun propellant and the addition of ablation inhibitors inside can effectively improve the combustion progressivity and extend the service life of the barrel weapon. However, deterring agents are inert with negative oxygen balance and ablation inhibitors are difficult to decompose, often resulting in ignition difficulty and aggravating the emission harmful phenomenon, reducing the battlefield survivability of weapon. In this paper, a synergistic strategy of nitrocellulose denitration and nano-ZnO loading is proposed for the first time, in which ZnO with excellent thermal conductivity is loaded on the surface of denitrated nitrocellulose to enhance thermal conductivity while improving ablation inhibition property and reducing the amount of ablation agents. Various structural characterizations confirmed the successful preparation of denitrated nitrocellulose-ZnO (DNC@ZnO) composite with structural integrity and controllable nano-ZnO loading concentration. The results of TG, DSC and TG-FTIR showed that the appropriate amount of loaded ZnO barely affected the thermal decomposition process and thermal stability of nitrocellulose. Subsequent studies confirmed the high thermal conductivity and ablation inhibition property of DNC@ZnO composite, and mechanisms for these properties were proposed. This work is of great importance for the design of gun propellant with both combustion progressivity, easy ignition, low ablation, and less emission harmful phenomena.