化学学报 ›› 2004, Vol. 62 ›› Issue (13): 1197-1204. 上一篇    下一篇

研究论文

2-羟基和4-羟基-3,5-二硝基吡啶铅盐的热行为、分解机理、非等温分解反应动力学及其在推进剂中的应用

陈沛1, 赵凤起1, 罗阳1, 胡荣祖1, 郑玉梅2, 邓敏智2, 高茵1   

  1. 1. 西安近代化学研究所, 西安, 710065;
    2. 中国科学院上海有机化学研究所, 上海, 200032
  • 投稿日期:2003-12-01 修回日期:2004-01-15 发布日期:2014-02-17
  • 通讯作者: 赵凤起,E-mail:npecc@21cn.com E-mail:npecc@21cn.com
  • 基金资助:
    兵器支撑基金(No.BZJ030901)和火炸药燃烧国防科技重点实验室基金(No.51455030101ZS3505)资助项目.

Thermal Behavior, Decomposition Mechanism and Non-isothermal Decomposition Reaction Kinetics of Lead Salts of 2-Hydroxy-3,5-dinitropyridine and 4-Hydroxy-3,5-dinitropyridine and Their Application in Propellant

CHEN Pei1, ZHAO Feng-Qi1, LUO Yang1, HU Rong-Zu1, ZHENG Yu-Mei2, DENG Min-Zhi2, GAO Yin1   

  1. 1. Xi'an Modern Chemistry Research Institute, Xi'an 710065;
    2. Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032
  • Received:2003-12-01 Revised:2004-01-15 Published:2014-02-17

在程序升温条件下,用DSC,TG,慢速裂解/傅里叶红外,研究了2-羟基-3,5-二硝基吡啶铅盐(2HDNPPb)和4-羟基-3,5-二硝基吡啶铅盐(4HDNPPb)的热行为、机理和动力学参数,提出了它们的热分解机理,计算了热爆炸临界温度,考察了它们对RDX改性双基推进剂的催化效果.结果表明:2HDNPPb和4HDNPPb主放热分解反应的表观活化能和指前因子值分别为252.34 kJ·mol-1,1019.30 s-1和187.39 kJ·mol-1,1013.74 s-1.由加热速率β→0的DSC曲线的初始温度(Te)和峰温(Tp)算得2HDNPPb和4HDNPPb的热爆炸临界温度值分别为327.64,336.57和323.90,333.96℃.2HDNPPb的热稳定性优于4HDNPPb.0.1 Mpa时,它们的放热分解过程动力学方程可表示为:
对2HDNPPb dα/dT=1020.48(1-α)[-ln(1-α)]3/5e-3.0351×104/T
对4HDNPPb dα/dT=1015.00(1-α)[-ln(1-α)]2/3e-2.2539×104/T
对含RDX改性双基推进剂,它们都具有催化燃烧和降低压力指数的作用.2HDNPPb的催化效果明显优于4HDNPPb.羟基在分子中所处的不同位置是影响热稳定性和催化效果的主要因素.

关键词: 2-羟基-3,5-二硝基吡啶铅盐, 4-羟基-3,5-二硝基吡啶铅盐, 热行为, 机理, 动力学参数, RDX改性双基推进剂, 催化效果

The thermal behavior, mechanism and kinetic parameters of the exothermic decomposition reaction of lead salts of 2-hydroxy-3,5-dinitropyridine (2HDNPPb) and 4-hydroxy-3,5-dinitropyridine (4HDNPPb) in a temperature-programmed mode have been investigated by means of DSC, TG-DTG and lower rate thermolysis/FT-IR.Their reaction mechanisms were proposed.Their critical temperatures of thermal explosion were calculated.The catalytic effects of 2HDNPPb and 4HDNPPb on the composite modified double base (RDX-CMDB) propellant containing RDX were studied.The results show that the apparent activation energy and pre-exponential constant of the major exothermic decomposition reaction of 2HDNPPb and 4HDNPPb, at 0.1 MPa, are 252.34 kJ·mol-1 and 1019.30 s-1, 187.39 kJ·mol-1 and 1013.74 s-1, respectively.The critical temperatures of thermal explosion of 2HDNPPb and 4HDNPPb obtained from the onset temperature (Te) and the peak temperature (Tp) are 327.64℃ and 336.57℃, 323.90℃ and 333.96℃, respectively.The thermal stability of 2HDNPPb is better than that of 4HDNPPb.Their kinetic equations of the major exothermic decomposition process at 0.1 MPa can be expressed as:
for 2HDNPPb dα/dT=1020.48(1-α)3/5e-3.0351×104/T
for 4HDNPPb dα/dT=1015.00(1-α)2/3e-2.2539×104/T
2HDNPPb and 4HDNPPb possess better catalytic effect and ability to reduce pressure exponent for RDX-CMDB propellant.In comparison with 4HDNPPb, 2HDNPPb has the higher catalytic efficiency.The positions of the hydroxyl group in the molecules were the principal factor affecting the thermal stability and the catalysis activity of 2HDNPPb and 4HDNPPb.

Key words: lead salt of 2-hydroxy-3,5-dinitropyridine, lead salt of 42hydroxy-3,5-dinitropyridine, thermal decomposition, mechanism, kinetic parameter, composite modified double base propellant containing RDX, catalysis