Study On Mechanical Properties Of Graphene/polymer Composites

Graphene has a unique two-dimensional nanostructure,the physical properties are very good,and because of its rich sources,graphene has become a very ideal nano filler for the preparation of polymer composite materials.How to prepare graphene/polymer nanocomposites and how to improve the mechanical properties of the composites have become one of the hottest topics in the field of graphene study.Graphene/poly lactic acid composites were prepared by melt blending method in this paper.In order to investigate the mechanical properties of the composites,the standard parts were prepared by injection molding method firstly.Based on the results of mechanical testing,the effect of the addition of graphene on the mechanical properties of poly lactic acid was analyzed and discussed.The results showed that the tensile strength and the elastic modulus of the composites increased with the increase of the content of grapheme.When the content of graphene is 5000ppm,the tensile strength is the highest,61.78MPa.Compared to poly lactic acid,the tensile strength increased 6.8%.However the impact strength of grapheme/poly lactic acid composites first increased and then decreased with the increasing of the content of graphene.The influence of graphene addition on the impact properties of grapheme/poly lactic acid composites was great.When the content of graphene is 1ppm,the impact strength of composites is the highest,reaching 4.375kJ/m~2.Compared to poly lactic acid,the impact strength increased 44.8%.Next,we used FDM method to prepare standard parts to test mechanical properties of graphene/poly lactic acid composite.By testing the mechanical properties of the printed products under different FDM processes,the influence of different FDM processes on the mechanical properties of the products was studied.The results show that when the FDM process parameter is set to the nozzle temperature is 220?,the printing speed is 30mm/s,the thickness of the layer is 0.2mm,the tensile strength of the sample is the highest,and the printing result is the best.The tensile strength,elastic modulus and elongation of FDM printing standard parts are lower than the injection molding ones.Probably because the FDM parts filling rate is not enough,and the combination between the layer and the layer is not close enough.The Graphene/PA6 composite material was prepared by melt blending method,and the FDM process of the material was studied by orthogonal test.The effects of different FDM processes on the printing quality and mechanical properties of the composite was studied.We draw the following conclusions:for the mechanical properties of Graphene/PA6 composite,the order of the influence factor is the content of the graphene,the temperature of the nozzle,the printing speed and the platform temperature.When the mass fraction of graphene is 0.05%,the nozzle temperature in FDM is 245?,the platform temperature is 70?,the printing speed is 27mm/s,the nozzle diameter is 0.4mm and the slice thickness is 0.2mm,the composite material in FDM can yield the best tensile mechanical properties.