Reaction Kinetics and Process Optimization for Nitration of 2-Methyl-4, 6-Dihydroxy-Pyrimidine
1,1-Diamino-2,2-dinitroethene (FOX-7) is a thermally stable insensitive high explosive. Fox-7 is synthesised by nitration of 2-methyl-4,6-dihydroxy- pyrimidine (MDP). Nitration of MDP is a low temperature and highly exothermic reaction. Adiabatic rise in temperature of this nitration reaction is very high (>220℃) which indicates that the conduct of reactions at lowest possible optimum temperature is safer and favourable. In order to optimise the reaction time without compromising yield, the reaction kinetics have been studied at three different temperatures (5℃, 15℃ and 25℃) using differential method. The effect of temperature on yield(％) of FOX-7 has also been studied at two more additional temperatures, 35℃ & 42℃. Since the nitration of MDP is sensitive to temperature, rate of reaction was studied at fixed temperature with the variation of time keeping all the other parameters constant In the present studies, it is found that optimum temperature of nitration is 15℃ and rate of reaction follows pseudo second order with a rate constant 0.0338 (min-1) (concentration-1) . The reaction time evaluated for 85％ conversion is around 1.8 hrs at 15℃ based on the kinetics, which resembles to calorimetric studies too. Activation energy of MDP nitration is found to be 42kJ/mole, using reaction kinetic data based on temperature dependent rate equation derived from the Arrheniuss law. Heat generation rate increases with the increase of reaction temperature.
nitration kinetics 2-Methyl-4,6-dihydroxypyrimidine FOX-7
A.K. MANDAL S.K. SAHU V.V. JADHAV V.L. NARASIMHAN
High Energy Materials Research Laboratory, Sutarwadi, Pune-411 021, India
国际会议
西安
英文
78-85
2007-10-23（万方平台首次上网日期，不代表论文的发表时间）