工艺温度对F2604/HMX复合粒子包覆效果及撞击感度的影响

Influence of Process Temperatures on the Coating Effect and Impact Sensitivity of F2604 /HMX Composite Particles

为了解工艺温度对PBX炸药性能的影响,采用相分离法将氟橡胶(F2604)包覆在奥克托今(HMX)表面,制备了F2604/HMX复合粒子;通过扫描电镜(SEM)和X射线光电子能谱(XPS)对复合粒子的微观形貌和元素含量变化进行表征;采用分子动力学模拟不同工艺温度下F2604对HMX包覆效果的影响;采用特性落高法测试了F2604/HMX复合粒子的撞击感度。结果表明,随着温度的升高,样品中的N元素含量先降低后升高,包覆度先升高再降低;当工艺温度为50℃时,复合粒子的表面平滑、规整,N元素含量最低,包覆度为58.25%,包覆效果最好;分子动力学模拟结果表明,50℃时F2604/HMX复合体系结合能最高,为197.24 kJ/mol,形成的F2604/HMX体系最稳定;随着温度的升高,撞击感度特性落高H 50先升高后降低,50℃时样品的特性落高最高,为81.7 cm,与20℃时相比提高了78.8%;50℃时,F2604和HMX之间的相互作用力最强,形成的复合体系稳定性最好,使得包覆和粘结效果增强,从而降低了撞击感度。

To understand the influence of process temperatures on the performance of PBX explosives,fluororubber F2604 was coated on the surface of HMX with phase separation method to form F2604/HMX composite particles.The microstructure and element content of the composite particles were characterized by scanning electron microscopy(SEM)and X-ray photoelectron spectroscopy(XPS).The influence of fluororubber on coating effect of HMX at different process temperatures were conducted by means of molecular dynamics simulation.The impact sensitivity was measured by the characteristic drop height method.The results show that as the temperature increases,the N element content of the sample first decreases and then increases,and the coating degree first increases and then decreases.When the process temperature is 50℃,the surface of the composite particles is smooth and regular.Meanwhile,the content of N element is the lowest and the coating degree is the highest(58.25%),which indicates that the coating effect is the best.The results of molecular dynamics simulation show that the binding energy of F2604/HMX is the highest at 50℃(197.24 J/mol).The interaction between fluororubber and HMX is the strongest,which means that the F2604/HMX system formed is the most stable.The characteristic drop height at 50℃is the highest with the value of 81.7 cm,which is 78.8%higher than that at 20℃.The binding energy is the highest and the interaction between F2604 and HMX is the strongest at 50℃.The stability of formed composite is improved,the coating and binding effects are enhanced,thereby,the impact sensitivity is reduced.