Abstract: The samples for the composite modified double-base (CMDB) propellant containing the high-nitrogen compound 3,6-bis(1H-1,2,3,4-tetrazol-5-yl-amino)-1,2,4,5-tetrazine (BTATz) using as a substitute of hexogen (RDX) were prepared and the burning rates were measured, the characteristics of the thermal decomposition and combustion were investigated systematically by the technologies of TG-DTG, PDSC, the single-shot flame photo, the temperature distribution of combustion, and the structure and element content of quenched surface. The results show that the energy property parameters of the original control DB propellant will be decreased with nitrocellulose (NC) and nitroglycerine (NG) of the propellant being substituted by BTATz with a low oxygen balance (OB), so, the content of BTATz in the propellant formulation should be appropriate. BTATz-CMDB propellants are suitable to be prepared by a solventless CMDB propellant extrusion technique. BTATz has a highlight potential to increase the burning rates of the propellants, especially with the catalyst system (the mixture of lead phthalate, copper adipate and carbon black) which has a positive effect on the main exothermal reaction of the propellant. The flame of BTATz-CMDB propellant has the general characteristic of the flame of the double-base propellant, but BTATz makes it feasible for the presence of the diffused flame clusters as without such a melting process as RDX, makes the combustion surface of the propellant look like loosing coral reef rather than melting state, and the flame becomes much strong. With the pressure increasing, the amount of the activation spots increases where the diffused flame clusters occur, the dark zone becomes very thin, the heat feedback on the combustion surface coming from the flame zone is increased, and the burning rate is accelerated. The catalyst system can affect slightly on the gas phase of the combustion reaction, but it can enhance the exothermic reaction close to the condensed phase and its surface, and change the structure of the combustion surface. During the combustion process of the propellant, the fresh catalyst will be collected on the combustion surface, catalyzing the decomposition and combustion, improving the burning rates of the propellants. 

Key words: 3,6-Bis(1H-1,2,3,4-tetrazol-5-yl-amino)-1,2,4,5-tetrazine (BTATz); Composite modified double-base propellant; Combustion property; Flame structure; Structure of quenched surface

摘要： 以新型高氮化合物3,6-双(1-氢-1,2,3,4-四唑-5-氨基)-1,2,4,5-四嗪(BTATz)取代RDX制得了BTATz-CMDB推进剂试样,获得了燃速结果,并利用TG-DTG,PDSC,单幅照相、燃烧波温度分布和熄火表面形貌及元素含量测试技术对推进剂的热分解特性及燃烧特性进行了系统研究。结果发现,BTATz的氧平衡值较低,用其取代双基推进剂中的NC和NG后,推进剂的各能量特性参量出现不同程度的降低,因此,BTATz在推进剂中的含量不宜太高。BTATz-CMDB推进剂适用于常规无溶剂成型工艺进行制造；BTATz在燃速提升方面具有突出潜力,尤其在对推进剂主放热反应催化加速的催化体系(邻苯二甲酸铅、己二酸铜和炭黑的混合物)作用下,燃速提升效果更加明显；BTATz-CMDB推进剂燃烧时的火焰符合双基系推进剂火焰的一般特征,但由于BTATz不存在类似RDX那样的熔融过程,该类推进剂燃烧产生了发散火焰束,燃烧表面由熔融状变为疏松珊瑚状,火焰强度增强；随着压强升高,燃烧表面产生发散火焰束的活性点增多,暗区迅速变薄,增加了火焰区向燃烧表面的热反馈,加速了燃烧反应；催化体系对推进剂燃烧反应的气相区影响不大,它加强了凝聚相及表面附近的放热反应,改变了推进剂燃烧表面的结构,在推进剂燃烧过程中,催化剂(新生态)在推进剂的燃烧表面富集,催化了推进剂的分解和燃烧,促进了推进剂燃速的提高。 

关键词: 3,6-双(1氢-1,2,3,4-四唑-5-氨基)-1,2,4,5-四嗪(BTATz); 改性双基推进剂; 燃烧特性; 火焰结构; 熄火表面