摘要
为了分析烧结过程对聚四氟乙烯(PTFE)包覆Al粉性能的影响,利用分子动力学手段计算了298 K和678 K时PTFE在Al2O3(001)、(010)及(100)晶面6×6晶层的结合能,利用耗散粒子动力学手段模拟了298 K和678 K时Al2O3/PTFE在不同时刻的介观状态。计算及模拟结果表明:298 K时,PTFE在Al2O3(001)、(010)及(100)晶面的6×6晶层的结合能分别为2 782.67、5 582.97及4 634.32 k J/mol;678 K时PTFE与Al2O3(001)、(010)及(100)晶面的结合能分别是2 835.29、5 537.54及4 608.49 k J/mol。低温时,PTFE和Al2O3混溶性差,两种物质发生明显分相;高温时,PTFE和Al2O3混溶性较好,没有发生明显的分相。烧结过程有助于PTFE在Al2O3中的扩散,同时还可以提高聚合物与Al2O3的混溶性,但对PTFE包覆Al粉的强度影响不大。
In order to analyze the effects of sintering process on the properties of aluminium powder coated by teflon（ PTFE）,the binding energy of PTFE on the 6 × 6 crystal layer of Al2O3（ 001）,（ 010） and（ 100） crystal plane at 298 K and 678 K were calculated by molecular dynamics method,and the mesoscopic state of PTFE- Al2O3 at different times at298 K and 678 K were simulated by dissipative particle dynamics method. Calculation and simulation results show that the binding energy of PTFE on Al2O3（ 001）,（ 010） and（ 100） crystal plane at 298 K is 2 782. 67,5 582. 97 k J/mol and4 634. 32 k J / mol,respectively; while at 678 K it is 2 835. 29,5 537. 54 k J / mol and 4 608. 49 k J / mol,respectively. The compatibility of PTFE and Al2O3 is poor at low temperature,for which the two substances are separated. At elevated temperature PTFE and Al2O3 present better compatibility,without obvious phase separation. The sintering process promotes the diffusion of PTFE in Al2O3 and also can increase the miscibility of the polymer and Al2O3. However,PTFE has little effect on the strength of coated aluminium powder.
出处
《爆破器材》
CAS
2015年第2期18-22,27,共6页
Explosive Materials
基金
国防科工委基础产品创新计划火炸药科研专项
