Effect Of Graphene Oxide On The Curing Performance Of GAP Spherical Propellant

In order to study the effect of graphene oxide(GO)on the properties of nonisocyanate curing system of GAP spherical propellant.In this paper,the curing formulations of GAP spherical propellant with different graphene oxide content was designed by using graphene oxide and GAP spherical propellant as raw materials,butyl nitrate ethyl nitramine(Bu NENA)as plasticizer and dipropargyl succinate(BPS)as curing agent.The curing kinetic parameters of different formulations were studied by rheological non-isothermal method.The effects of graphene oxide contents on the morphology,thermal stability,mechanical properties and thermal mechanical properties of cured systems were investigated.The main studies are as follows.In order to improve the properties of GAP spherical propellant composites containing graphene oxide.In this study,n-butylamine,propargyl bromide and potassium tert-butyl alcohol were used as modifiers to modify the surface of graphene oxide in two steps.Alkyne graphene oxide(GO-C?CH)was prepared and introduced into GAP spherical propellant curing systems.The effects of GO and GO-C?CH on the curing kinetics of GAP spherical propellant were analyzed by non-isothermal rheological test.The results show that the non-isothermal curing system of GAP spherical propellant and BPS conforms to the self-catalytic reaction model.The apparent activation energy of the curing reaction between GAP spherical propellant and BPS ranges from 121 to 133 k J/mol.The addition of GO and GO-C?CH does not change the curing reaction model,but has an effect on the curing rate and apparent activation energy.With the increase of GO content,the maximum storage modulus at the end of curing increases,and the curing start temperature decreases accordingly.When the GO content is less than 1%,as the GO content increases,the apparent activation energy of the curing system decreases,the reaction order increases and the pre-exponential factor decreases.When the GO content exceeds 1%,the apparent activation energy of the curing system increases,the reaction order increases and the pre-exponential factor increases due to the agglomeration effect of GO.Since GO-C?CH is involved in the curing reaction,the maximum energy storage modulus reached at the end of curing increases for the same amount of GO-C?CH compared to GO,and the apparent activation energy and pre-exponential factor of the curing system decreased,and the reaction order increased.The effects of graphene oxide contents on the morphological structure,thermal decomposition,weight loss,mechanical properties,thermal expansion and dynamic mechanical properties of GAP spherical propellant composite systems were investigated.The results showed that GO existed in the GAP spherical propellant composite systems in a physical dispersion manner and did not react with GAP spherical propellant.GO-C?CH was involved in the curing reaction of GAP spherical propellant and enhanced interaction forces between the modified graphene oxide and the GAP spherical propellant curing matrix.For GAP spherical propellant composite system with GO content below 1%,GO can be dispersed relatively uniformly.With the increase of GO content,the thermal stability,thermal decomposition activation energy and mechanical properties of the composite system gradually increased,and the thermal expansion coefficient gradually decreased.And when the GO content exceeds 1%,due to the agglomeration of GO,the curing structure will be destroyed to a certain extent,resulting in the decrease of thermal stability,thermal decomposition activation energy,mechanical properties and thermal expansion coefficient of the composite system.Compared with GO,the same content of GO-C?CH improved the curing properties more obviously.GO-C?CH can significantly improve the thermal stability and mechanical properties of the composite system.Because GO-C?CH will react with GAP in GAP spherical propellant by 1,3-dipolar cycloaddition,GO-C?CH will have good surface bonding with polymer matrix,so that the composite system has better curing performance.