DNTF与PMMA热稳定性和力学性能的分子动力学模拟

Molecular Dynamics Simulation of Thermal Stability and Mechanical Properties of DNTF and PMMA

为探究聚甲基丙烯酸甲酯(PMMA)对3,4-二硝基呋咱基氧化呋咱(DNTF)热稳定性和力学性能的影响,利用分子动力学模拟(MD)研究了不同温度下DNTF(111)体系和DNTF(111)/PMMA复合体系的热稳定性(引发键长和内聚能密度)和力学性能[弹性系数(C_(ij)),拉伸模量(E),体积模量(K),剪切模量(G),柯西压(C_(12)—C_(44))和泊松比];使用差示扫描量热法(DSC)进一步研究了两种体系的热稳定性。结果表明,在298~398K内,PMMA的加入使DNTF(111)体系的引发键键长减小0.016,CED(内聚能密度)增大0.05kJ/cm^(3),热分解峰温和活化能升高2℃和1.59kJ/mol。因此,PMMA被认为是改善DNTF热稳定性的有效高分子钝感剂。此外,力学性能模拟研究表明,PMMA使DNTF(111)的E、K和G降低0.58、0.32和0.22GPa,K/G提高0.04,说明PMMA也可以有效改善DNTF的力学性能。

In order to investigate the effect of polymethyl methacrylate(PMMA)on the thermal stability and mechanical properties of 3,4-dinitrofurazanfuroxan(DNTF),the thermal stability[trigger bond length and cohesive energy density(CED)]and mechanical properties[elastic coefficient(C_(ij)),tensile modulus(E),bulk modulus(K),shear modulus(G),cauchy pressure(C_(12)—C_(44)),and Poisson′s ratio]of the DNTF(111)system and the DNTF(111)/PMMA composite systems at different temperatures were studied by molecular dynamics simulations(MD).The thermal stability was further experimentally investigated by using differential scanning calorimetry(DSC)technique.The results show that the trigger bond length of DNTF(111)system decreases by 0.016,the CED increases by 0.05kJ/cm^(3),and the thermal decomposition peak temperature and the activation energy(E_(a))increases by 2℃ and 1.59kJ/mol at 298—398K with the addition of PMMA.Thus,PMMA is considered as an effective binder to improve the thermal stability of DNTF.Moreover,the mechanical property simulations show that PMMA reduces the E,K and G of DNTF(111)by 0.58,0.32 and 0.22GPa,and increase the K/G by 0.04,which indicates that PMMA can effectively improve the mechanical properties of DNTF.