Preparation And Characterization Of Supramolecular Gel Propellants With Metal Accelerants

Propellants which are widely used in defense industry,aerospace and other fields can provide energy for rocket,missile and all kinds of weapon systems.However,traditional solid propellant and liquid propellant have some deficiency.In order to meet the needs of practical applications,gel propellants with high stability and safety have become the research direction in recent years.Synthesizing the gelators with strong gel ability and good combustibility is the center of prepare gel propellants.Therefore,the low-molecular mass gelators(LMWGs)exhibit superior thermal reversibility,multistimuli responsiveness and self-healing properties,are expected to be applied in preparation of gel propellant materials.Two series of D-gluconic acetal supramolecular organic gelators Gn and Cn were synthesized,and the relationship between the structure and gel properties were studied.These two kinds of compounds were used to prepare gel propellants,and their rheological properties,application potential were discussed.Gn and Cn showed good gel abilities for aromatic solvents,fuel JP-10 and RP-1.Increasing the length of alkyl chains would weaken the gel ability.More interestingly,G18 can gel JP-10 solvent at room temperature.SEM observed that the gelator with long alkyl chains tended to form a one-dimensional fiber structure.Rheological measurements showed that Gn/JP-10 and Cn/JP-10 gel materials had thixotropy and could recovery instantly,in addition,the thixotropic property of short alkyl chains structure were higher than that of long alkyl chains gel material.Furthermore,to increase the overall performance of the rocket motor system,metal accelerant powders could be introduced to the gel propellant,which would provide higher specific impulse and volumetric loading to propellants.Though,how to keep the metal well dispersed in propellant system was a technical difficulty.Therefore,the LMWGs propellants containing metal accelerant agents were prepared,and these metalized gel propellant systems could be stable for months.This work,for the first time,studied the influence of metal accelerant agents added to LWMGs propellants,rheological experiment found that the presence of metal accelerant agents in Gn-based gel could significantly increase their mechanical strength,yield stress and viscosity,as well as thixotropy.And SEM figures demonstrated that 50 nm Al powder changed the stack mode of nonmetallized G8 gel,from the dense fiber network structures into the nano-sphere aggregates.