Study On The Application Of TMETN And NGEC In Propellants

In this paper,high-energy and high-intensity propellants containing cellulose nitrate glycerol ester(NGEC)and trimethylolethane trinitrate(TMETN)were studied.Based on the formulation of nitramine propellant,different trimethylolethane trinitrate(TMETN)content,different cellulose nitrate glycerol ester(NGEC)and different nitrocellulose nitrogen content of high energy and high intensity propellant samples were prepared by replacing nitroglycerin(NG)with trimethylolethane trinitrate(TMETN)partly,changing the nitrogen content of nitrocellulose and replacing nitrocellulose(NG)with cellulose nitrate glycerol ester(NGEC)partly,improving the mechanical properties of the propellant while maintaining the high energy of the propellant.Minimum Gibbs free energy method was used to calculate and analyze the energy of the propellant.The effects of the components on the energy performance of the propellant were studied.On the basis of theoretical calculation,the formula composition of high energy and high intensity propellant was determined and then prepared a series of propellant samples,impact tester and material testing machine were used to test its impact strength and compression strength at different temperatures(-40℃、20℃、50℃).The combustion performance was tested by a closed explosive device at different temperatures(-40℃、20℃、50℃).The test results showed that in the test range,as TMETN replaces NG gradually,the low-temperature impact strength of high-energy and high-intensity propellant was gradually increasing while impact strength under the high-temperature and normal-temperature was reduced.The change regulation of compressive strength under high temperature,normal temperature and low temperature were consistent and increase gradually.The p-t,u-p and L-B curves at different temperatures were smooth and have no abnormal fluctuations.The combustion time increased with the increase of TMETN content,and the burning rate was gradually decreasing,but the amplitude was not large.On the basis of the formula containing 10% TMETN high-energy and high-intensity propellant,the nitrogen content of nitrocellulose was changed,and a series of samples were prepared.The test results showed that: the change trend of impact and compressive strength of propellant under high temperature,normal temperature and low temperature was observed consistently with the increasing of nitrogen content in nitrocellulose,they all showed a trend of a small increase and then a gradual decline.When the nitrogen content is 12.4%,the best mechanical properties are obtained.The effects of NGEC content and different batch numbers(1#、2#、3#)on the mechanical and combustion properties of propellants were studied.In the experimental range,with the increase of 1# and 2# NGEC(the content increased from 0 to 16%)content,the impact strength and compressive strength of high-energy and high-intensity propellants all showed a downward trend.However,the increase in the content of 3# NGEC(content from 0 to 40)gradually increased the impact strength at different temperatures.The p-t,u-p and L-B curves at different temperatures were smoother,which was consistent with the normal burning behavior of tubular propellant,indicating that there was no obvious fragmentation of the propellant under normal pressure and constant volume combustion.