Study On Interfacial Mechanical Properties Of Graphene Phthalonitrile Based On Molecular Dynamics

Phthalonitrile resin(PN)has the best thermal performance among all kinds of common resins(epoxy resin EP,polyimide PI,cyanate resin CE,bismaleimide resin BMI,etc).It has excellent thermal resistance,thermal resistance Tg>400℃,flame retardant and comprehensive performance.It was developed and applied by US Navy Laboratory in the last century.It is the only advanced resin that can meet the needs of the navy and has a broad application prospect in the field of aerospace.In recent years,our research group has carried out a series of researches on phthalonitrile resin,including the research and application of carbon fiber reinforced phthalonitrile resin matrix composites,and the modification of phthalonitrile resin,etc.The research results show that phthalonitrile resin has high performance,but there are serious interface problems in phthalonitrile resin matrix composites.The interface problem seriously affects the mechanical properties of phthalonitrile resin matrix composites,so for the existence of this short board of phthalonitrile resin,this study by using 2D material graphene,and phthalonitrile resin composition of graphene phthalonitrile resin nanocomposites,enhance the mechanical properties of phthalonitrile resin.Based on the molecular dynamics(MD)simulation,in LAMMPS software,to simulate the function of fossil ink olefine from(PN)phthalonitrile resin matrix from process,was studied by using functional graphene treated group,the graphene phthalonitrile resin nanocomposites interface into chemical bonding force of the van der Waals force,hydrogen bond,van der Waals force interface,Change in interface performance.The micro-separation failure and strengthening mechanism of the interface between the monolayer graphene sheet and the PN matrix of the phthalonitrile resin were studied.Meanwhile,the mechanical properties of the interface of the phthalonitrile resin were also discussed under different simulated loading rates and conditions.The results show that the normal separation strength of the graphene/phthalonitrile resin interface is much higher than the in-plane shear strength during in-plane shear and normal separation simulation,and the shear slip behavior of the interface is the main interface mechanical behavior during interface failure.In the process of separation and failure,the interaction energy between graphene and PN matrix atoms changes at the elastic stage.After the elastic stage,hydrogen bonding and van der Waals force in the non-binding energy increase rapidly.After functionalization of oxidized functional groups,the interface interaction between graphene and phthalonitrile resin(PN)is improved,which is more conducive to stress transfer,and therefore the interface strength is enhanced.The research in this paper is helpful to understand the failure mechanism of functionalized graphenereinforced phthalonitrile resin polymer materials at the micro scale.It is of theoretical significance to explore new functionalized graphene/phthalonitrile resin polymer materials.