Study On Green Synthesis Process Of Hexanitrobibenzyl

2,2’,4,4’,6,6’-Hexanitrobiphenyl,with the code name of HNBB,is the main raw material for the two-step synthesis of high-energy insensitive heat-resistant explosive HNS.In this paper,a green process for the synthesis of HNBB with TNT as raw material and oxygen oxidation in aqueous solution is proposed,followed by the better conditions for the synthesis process obtained through single factor experiment and orthogonal experiment.Moreover,studies were carried out for the safety shown by the synthesis process and the thermal stability of the products.A green synthesis process is preferably obtained using water as the solvent,after making comparison between the melting point and yield of the reaction product of oxidizing TNT to synthesize HNBB obtained from different oxidants,catalysts,alkali solutions adopted to make adjustments to p H and different methods of material feeding.In other words,using oxygen as an oxidant,and Cu-Fe composite Oxides as catalysts,Na OH solution was added dropwise to make adjustments to the p H during the process of reaction.In the process,optimization was obtained through the green synthesis process,and the best process conditions were obtained through single factor experiment and orthogonal experiment.The p H value of the reaction was adjusted to 10 adopting Na OH solution,with the reaction time as 6 h,the reaction temperature as 85℃,the oxygen passing rate as 0.5 L/min,the copper-iron ratio of the catalyst as 1.5:1,and the amount of the catalyst as 0.15 g.The yield rate of HNBB was 61.5% under the condition.The evaluation over the safety of the green oxidation process was carried out using the reaction calorimeter and adiabatic acceleration calorimeter.It was shown by the results that the thermal hazard level obtained from the evaluation of the risk matrix method were acceptable,and the reaction hazard level obtained from the runaway situation analysis method was level 1.The research on the thermal decomposition performance of the product hexanitrobibenzyl came to the conclusion that the adiabatic decomposition of hexanitrobibenzyl was divided into three stages,and no strong autocatalytic effect was available in the thermal decomposition.