CL-20/DNB共晶高温热解的ReaxFF反应分子动力学模拟  

Reax FF Reactive Molecular Dynamics Simulations of Thermal Decomposition under High Temperature for CL-20/DNB Cocrystal

作　　者：苗瑞珍 刘伟帅 王建[1,2] 康志鹏[1,2] 杨潞霞[3] 荆兴斌[1,2] 付一政[1,2] 刘亚青[1,2] 

机构地区：[1]中北大学山西省高分子复合材料工程技术研究中心,山西太原030051 [2]中北大学材料科学与工程学院,山西太原030051 [3]山西大学商务学院信息学院,山西太原030051

出　　处：《含能材料》2016年第2期111-117,共7页Chinese Journal of Energetic Materials

基　　金：高等学校博士学科点专项科研基金(20131420120004);山西省高校'131'领军人才工程项目;山西省高等学校科技创新项目;山西省青年科技研究基金(2014021019-7)

摘　　要：基于Reax FF力场,采用反应分子动力学方法(Reactive Molecular Dynamics,RMD)研究了高温条件下(2000,2500 K和3000K)六硝基六氮杂异伍兹烷(CL-20)/1,3-二硝基苯(DNB)共晶的初始热解机理以及一些主要产物随时间的分布情况。结果表明:CL-20/DNB共晶热解过程中温度越高,系统达到平衡所需时间越短,生成的产物越多,势能下降也越多。各个温度下CL-20均先于DNB快速分解完毕,随温度升高DNB的热解速率显著加快。CL-20/DNB共晶主要热解产物为NO_2、NO、N_2、H_2O、HNO3、HON、HONO和CO_2等,其中NO_2是由CL-20中N—NO_2键和DNB中C—NO_2键的断裂所生成,这是主要的初始引发反应,其数量迅速达到最大值后通过异构化生成ONO自由基,接着进一步生成N_2、NO、HONO、HON和H_2O等。在2500 K和3000 K条件下模拟后期体系中会有较大的含碳团簇出现,这是富碳炸药爆轰过程中的常见现象。The initial thermal decomposition pathways as well as some important products generating mechanism of hexanitrohexaazaisowurtzitane（CL-20） /1,3-dinitrobenzene（DNB）cocrystal at high temperatures（2000,2500 K and 3000 K）were studied by reactive molecular dynamics simulations using ReaxFF force field. Results show that with the increasing of temperature during the thermal-decomposition process, the time to balance and potential energy decrease, while the quantity of products increases. The simulation results show that all the CL-20 molecules decompose faster than that of DNB, and as the temperature rises, the decomposition rate of DNB increases significantly. According to the product identification analysis,the main thermal decomposition products are NO2, NO, N2, H2O, HNO3, HON, HONO and CO2 for cocrystal. The major initial decomposition mechanism is the breaking of N—NO2 in the CL-20 and C—NO2 in the DNB, which contributes to the formation of NO2. And then, the number of NO2 increases to the peak rapidly and decreased subsequently. After the NO2→ONO rearrangement, it participates in other reactions and eventually occur N2, NO, HONO, HON, H2O and so on. In addition, the simulation results indicate that carbon-containing clusters formed in the later stage of decomposition at 2500 K and 3000 K, which is a common phenomenon during the detonation of rich carbon-containing explosives.

关 键 词：ReaxFF力场 反应分子动力学 六硝基六氮杂异伍兹烷(CL-20)/1 3-二硝基苯(DNB)共晶 热解机理 

分 类 号：TQ560.1[化学工程—炸药化工]