2,6-二苦氨基-3,5-二硝基吡啶(PYX)晶形优化及性能表征  

Crystal Shape Optimization and Performance Characterization of PYX

作　　者：罗西 常海[1] 周文静[1] 赵娟[1] 栾洁玉[1] 刘红妮[1] LUO Xi;CHANG Hai;ZHOU Wen-jing;ZHAO Juan;LUAN Jie-yu;LIU Hong-ni(Xi′an Modern Chemistry Research Institute,Xi′an 710065,China)

机构地区：[1]西安近代化学研究所,陕西西安710065

出　　处：《火炸药学报》2023年第4期306-314,共9页Chinese Journal of Explosives & Propellants

基　　金：国家自然科学基金(No.21805226)。

摘　　要：为了优化2,6-二苦氨基-3,5-二硝基吡啶(PYX)的晶体成形性,改善PYX的应用性能,采用溶剂-反溶剂法对PYX进行重结晶,确定了较优的结晶体系,探究了PYX晶体形貌和粒度分布的影响因素及规律,获得了较优的重结晶条件,分析了重结晶前后PYX的晶型结构、热性能和机械感度。结果表明,以1-甲基-2-吡咯烷酮(NMP)为溶剂、水为反溶剂,在结晶温度65℃、搅拌速率300r/min、结晶浓度20mg/mL、反溶剂滴加速率2mL/min的结晶条件下能够制得形状规则的立方状PYX晶体,晶体长径比较重结晶前显著减小,无明显缺陷,且具有良好的表面光滑度;通过重结晶减小了PYX的平均粒度,优化了PYX的粒度分布均匀性,重结晶后PYX的粒径(d 50)较重结晶前减小了49.51μm,粒径跨度(S)较重结晶前减小了0.27;重结晶前后PYX的晶型结构未发生变化,通过重结晶能够提高PYX的热稳定性,降低PYX的机械感度,重结晶后PYX的热分解峰温和热爆炸临界温度较重结晶前分别提高了5.0℃和6.6℃,撞击感度和摩擦感度较重结晶前分别降低了20%和16%。In order to optimize the crystal formability and improve the application performance of PYX,the solvent-antisolvent method was used to recrystallize PYX,and the better recrystallization system was determined.The influencing factors and laws of PYX crystal morphology and particle size distribution were explored,and the recrystallization conditions were optimized.The crystal structure,thermal property and mechanical sensitivity of PYX before and after recrystallization were analyzed.The results show that using 1-methyl-2-pyrrolidone(NMP)as solvent and water as antisolvent,the regular cubic crystals can be prepared under the conditions:crystallization temperature is 65℃,stirring rate is 300r/min,crystallization concentration is 20mg/mL,and antisolvent adding rate is 2mL/min.The crystal length-diameter ratio is significantly smaller than those before recrystallization,and has no obvious defects,and with good surface smoothness.Recrystallization can reduce the average particle size and optimize the uniformity of particle size distribution of PYX.The particle size(d 50)and the particle size span(S)of PYX after recrystallization is reduced by 49.51μm and 0.27 compared with that before recrystallization,respectively.The crystal structure of PYX does not change after recrystallization.Recrystallization can improve the thermal stability of PYX and reduce the mechanical sensitivity of PYX.After recrystallization,the thermal decomposition peak temperature and thermal explosion critical temperature of PYX are[JP2]increased by 5.0℃and 6.6℃,and the impact sensitivity and friction sensitivity are decreased by 20%and 16%,respectively.[JP]

关 键 词：物理化学 重结晶 PYX 晶体形貌 粒度分布 热性能 机械感度 

分 类 号：TJ55[兵器科学与技术—军事化学与烟火技术] O64[理学—物理化学]