Simulation Of Properties Of Cyclopropane/butylcyclobutane And Its Methyl Derivatives

High-density hydrocarbon fuel is a synthetic hydrocarbon fuel to improve the performance of aerospace engines.Compared with conventional fuels,it has high density and high calorific value and has become a hot research topic in recent years.Among the high-density hydrocarbon fuels,there is a type of high-density hydrocarbon fuels based on three-and four-membered ring hydrocarbon fuels.Because of their higher tension energy,they are favored by research experts in related fields.This subject is designed based on the four-membered ring structure and directed synthesis of related four-membered ring high-energy fuels.It mainly calculates the energy of molecules by quantum chemistry methods,predicts related thermodynamic performance parameters,such as density,viscosity,flash point,enthalpy of formation,specific impulse,etc,and studies the structure-activity relationship of tension ring fuel molecules in order to screen out reasonable structure.The fuel molecular structure with high tension energy provides support.The main contents are as follows:（1）The influence of the number of methyl substituents on the formation enthalpy and specific impulse of cyclopropylcyclobutane and its derivatives was explored,and it was found that as the number of methyl substituents increased,the specific impulse and enthalpy of formation decreased.The viscosity and flash point are moderate,and the influence of the position of the substituent on the properties of cyclopropylcyclobu-tane and its derivatives is discussed.It is found that the specific impulse depends on the enthalpy of formation.When the substituent is ortho-substituted on the three-membered ring,and when it is para-substituted on the four-membered ring,its molecular stability is the best,and the enthalpy of formation and specific impulse are larger.The optimal mixing ratio of cyclopropylcyclobutane and liquid oxygen was determined by Explo 5software to be 29.5:70.5,and the main components of combustion products were CO（36.89%）,CO₂（28.67%）,H₂O（12.65%）.（2）The influence of the number of methyl substituents on the formation enthalpy and specific impulse of bicyclobutane and its derivatives was explored.It was found that as the number of methyl substituents increased,the formation enthalpy and specific impulse showed a decreasing trend.The overall performance of bicyclobutane and its methyl derivatives is better than conventional fuel JP-10.When the substituent is para-substituted,its molecular stability is the best,the enthalpy of formation and specific impulse are larger,while the ortho-position substitution has a weakening effect on the enthalpy of formation and specific impulse of bicyclobutane derivatives.When the mass mixing ratio of bicyclobutane and liquid oxygen is 28.5:71.5,the main components of combustion products are CO（34.64%）,CO₂（13.89%）,and H₂O（29.54%）.With the increase in the number of methyl substituents,the H/C ratio also increases,the proportions of CO,OH,H,O₂,and O decrease,while H₂O,CO₂,and H₂show an increasing trend.（3）The configuration of bicyclobutane was simulated and calculated,and its synthesis process was deeply explored.The crude product was obtained through the grignard reaction of cyclobutylmagnesium bromide,which was washed,dewatered,filtered,distilled,and columnar.Purification is carried out by means of analysis,etc,firstly through distillation to obtain a bicyclobutane product with a purity of 52.9%,and then column chromatography to obtain a bicyclobutane product with a purity of 83.4%.Finally,the synthesis mechanism of the reaction was discussed in depth,and it was found that the bicyclobutane obtained from the grignard reagent cyclobutylmagnesium bromide requires a two-step reaction.First,two free cyclobutyl ions form a carbon-metal bond with normal divalent copper.Because the bond of this valence state is in a transition state,then a bicyclobutane molecule with a stable structure and copper element are formed.