Effect Of Magnetic Field And Electric Field On Dielectric Properties And Micro-Structure Of Polymer/Nano Graphite Composites

Polymer matrix composites is one of the earliest composite materials thatpeople pay close attention to and do research about. Inorganic fillers are mostlyin nanometer and micron scale, therefore they are at non equilibrium state inthermodynamics, they are sensitive to external field. At the same time, polymer-based material are sensitive to the excitation of external fields. Therefore it hasbecome one of the important research direction in composite materials field todevelop and study new polymer matrix composite materials with high perfor m-ance using electric field and magnetic fie ld.Review of the study of polymer matrix composites process, the experiment s isthe main method of research which is not only a waste of manpower, materialand financial resource, but also a wrong understand of the composite conductivemechanis m. And with the development of finite element simulation technology,this problem has been resolved. Using the finite element technology, themicrostructure of the matrix composites is more intuitive analysis and simulation.Combined with the results of experimental studies, it is very useful for us tostudy the conductive mechanism of the composites.The paper first does research on nano graphite volume, diameter thicknessratio and distribution, and their influence to the electrical properties ofpolymer/nano graphite composites. The results show that keeping the diameterthickness ratio stable, the conductivity of composites increases obviously whileincreasing its volume fraction, and keeping the volume fraction stable, stillincreases while increasing the diameter thickness ratio. the conductivity ofcomposites increases as the circle between nano graphite and the Z axis increaseswhile array orientation has its rules. This paper aslo prepares low density polyethylene/nano graphite and ethylene vinyl acetate copoly mer/graphitecomposites, and exerts steady magnetic field or electric fie ld during the com-posite pressing molding, the experiment studies the influence from electric,magnetic field treatment to polymer/nano graphite composites microscopicstructure and dielectric properties. The experiment result shows: electric fieldand magnetic field treatment leads to the growth of DC conductivity of polymer/nano graphite composites, and the growth trend is more obvious while increas-ing nano graphite volume. at the same time, relative permittivity and dissipationfactor of the treated composites increase, and the effect of non uniform electricfie ld treatment is more obvious than uniform electric field treatment.