Study On Dielectric Properties Of Carbon Filled Electrospun PET Fiber

In order to meet the development needs of miniaturization and high performance of capacitors,the development of dielectric materials with high dielectric constant,low dielectric loss and easy processing has become an urgent need.In this paper,graphite and multi-walled carbon nanotubes(MWCNTs)are used to fill PET,and PET composites are prepared by electrospinning,and the effects of different filling modes on the dielectric properties of PET composites are studied.Firstly,the effects of spinning parameters on the morphology and diameter of PET fibers were studied.The PET fibers were prepared at a concentration of 12wt%-20wt%spinning solution and an injection rate of 0.02ml/min-0.03ml/min.The results show that when the concentration of PET spinning solution is 18wt%and the injection rate is 0.025ml/min,the spinning effect is the best.At this time,the prepared fiber surface is smooth and the diameter is evenly distributed between 580nm-620nm.Secondly,the dielectric properties of the prepared graphite/PET composite and MWCNTs/PET composite were studied.The results show that after the introduction of graphite and MWCNTs,the dielectric constant of the composite material is significantly improved,which is 87.46 and 107.58 times higher than that of pure PET film.Finally,the dielectric properties of the PET composite filled with graphite and MWCNTs were studied.It was found that when the filling amount of graphite and MWCNTs was 20wt%and 11wt‰,the maximum permittivity reached 365.54,which was 40.21%higher than that of graphite alone.Two kinds of fillers with different dimensions can produce synergistic effect on the structure and make the dielectric constant of the composite significantly increase.This study shows that the introduction of graphite and MWCNTs can significantly increase the dielectric constant of PET composites,which can realize the preparation of dielectric materials with high dielectric constant in a relatively low filling amount,and has a good application prospect in the field of capacitor membrane.