Preparation And Properties Of Silicone Rubber Composite Dielectric Elastomer

Dielectric elastomer（DE）is a type of electric field type electroactive polymer material that can produce greater deformation under the action of an electric field and has a faster recovery speed.It has the advantages of high energy density,large strain,low quality,and commercialization,and has become the most widely concerned and researched electroactive polymer material.In this paper,copper calcium titanate（CCTO）particles were selected as the filling phase,and silicone rubber（PDMS）was used as the matrix to prepare a new type of CCTO/PDMS dielectric elastomer material.This article analyzed the structure of the dielectric elastomer,and tested its mechanical properties,dielectric properties and driving deformation.This paper used three silane coupling agents to modify the CCTO,selected the modified particles with the best dispersion effect,prepared the dielectric elastomer material,tested its performance,and compared it with the unmodified dielectric elastomer material.Finally,using the method of finite element analysis,the actual test results were compared with the simulation results.The results show that as the content of CCTO increases,the dielectric constant and elastic modulus of the dielectric elastomer also increase,and the dielectric loss remains basically unchanged at a frequency of 100 Hz.When the filling amount reaches 20 wt%,the dielectric constant of the dielectric elastomer reaches 5.8（100 Hz）,an increase of 120%while the dielectric loss at this time is only 0.0038,the elastic modulus is only 0.54 MPa,and the conductivity is low at10^-7.When the filler in an amount of 5 wt%,the strain parameter pure PDMS is2.5 times,the deformation of the drive 33.8%.Through structural characterization,three silane coupling agents successfully modified CCTO.By comparing the results of scanning electron microscopy,it is found that the CCTO modified by KH560 has the best dispersibility in the PDMS matrix.Based on this,a modified CCTO/PDMS dielectric elastomer was prepared.The improvement of dispersion improves the dielectric constant.Compared with unmodified PDMS,when the filling content is 20 wt%,the dielectric constant reaches 6.5（100 Hz）,which is compared with unmodified PDMS.An increase of 150%.However,the improvement of the elastic modulus is greater,resulting in a decrease in its strain parameters,and the electromechanical conversion efficiency has not been significantly improved.When the filling amount of modified CCTO particles is 5 wt%,the driving deformation of the dielectric elastomer becomes 27.4%.The COMSOL software was used to model the dielectric elastomer and the finite element analysis（FEM）method was used to solve the results.The simulation results and the experimental results under low field strength are not much different,while the simulation results under high field strength are higher than experimental results.It is determined that the Maxwell stress is mainly distributed in the Z-axis direction of the inner surface,and the maximum deformation limit is 68.449 based on the thermodynamic model.