Study On Kinetics Of HTPB-based Bonding System

Polymer Bonded Explosive(PBX)is currently the most widely used in the military one of the varieties of hybrid explosives.As the name suggests,the bond system in PBX explosives has a very important role which directly affects the curing reaction process,explosive properties,mechanical properties and storage properties of PBX.At present,the curing end point of PBX is relied on experience in engineering application.It lacks the scientific basis of theory and calculation and can not determine exactly when the curing reaction can reach the curing end.In this paper,the optimal composition and ratio of the binder system are obtained by optimizing the bonding system.Then the isothermal and non-isothermal differential scanning calorimetry were used to study the kinetics of the curing reaction.Finally,on the basis of the optimum curing system and the optimal curing time,the mechanical properties and storage properties of the binder system were studied.The main research works of this paper is summarized as follows:(1)Through the combination of theory and experiment,the range of the objective function with three factors of viscosity,hardness and solidification time was determined.The optimal composition and ratio of the plasticizer,curing agent and catalyst in the HTPB bonding system were HTPB: DBP:TDI:T12 = 50:50: 3.79: 0.06.(2)Based on the optimal bonding system,the curing kinetics of the bonding system was studied by isothermal and non-isothermal differential scanning calorimetry,the DSC curves and data of the system were analyzed.The kinetic parameters of the curing reaction were obtained by Kissinger method,Ozawa method and Crane method.The influence of the curing degree on the curing reaction,the influence of the curing time,the curing time and the curing temperature,the change curve of the reaction conversion difference with time were studied.The relationship between curing time and temperature was obtained by fitting.When the curing temperature is 60 ?,the time required for complete curing is about 3.91 days,which is basically consistent with the curing time of 4 ~ 6 days in engineering application.So as to provide a solution to the curing end point encountered in engineering applications.(3)The optimum adhesive system was cured at the optimum curing time and temperature.The mechanical properties of the samples at different temperatures were studied and characterized.At the same time,the accelerated aging test was carried out.The experimental results show that the optimal mechanical properties of the system are excellent and meet the requirements of PBX storage for 30 years.