Study On Piezoelectric Damping Materials

With the development of science and technology,the requirements for the materials with the function,performance,compound and intellectualization are also increased.The piezoelectric material as the main modern functional materials,at present,can realize the transformation between mechanical vibration energy and electrical energy,but if the mechanical vibration energy cannot timely transform into electric energy,the resonance might happen to it which would result in a material aging.Consequently,in this paper,preparing piezoelectric materials with damping properties,which made composites to have both electrical and damping properties(1)Polyester type polyurethane and polyether type polyurethane are blended to form polyurethane PU with wide damping temperature range,and the piezoelectric properties of poly(vinylidene fluoride)PVDF were incorporated into the matrix in the solution method,we got the piezoelectric damping composite material(PVDF/PU).Results of IR and XRD analysis showed the absorption peak of PVDF β phase;Results of DMA curves show that the peak value of tanδ increases continuously with the increase of PU content,the value of loss factor peaks rising from 0.043 to 0.33,and the damping peak moved to high temperature,if the mass ratio of PVDF and PU was 6:4,the composite had great damping effect.The analysis of electrical performance shows that the piezoelectric constant is the largest when the mass ratio of PVDF and PU was 6:4 and the dielectric constant of the composite increases gradually with the content of PVDF increasing.Results of dielectric analysis showed when the mass ratio of PVDF and PU was 8:2,dielectric constant had biggest value,and the biggest value was 11.84;To sum up,the mass ratio of PVDF and PU was 6:4,the composite material have the best comprehensive performance.(2)Conductive carbon black into the PVDF/PU matrix,results of IR analysis showed the absorption peak of PVDF β phase;Dielectric performance tests show that with the increase of the content of conductive carbon black,the dielectric constant of composite materials increased at different levels,and dielectric loss have increased slowly,the addition amount of conductive carbon black was 6wt.%,the biggest value of the dielectric constant was 119 which was 17 times of the PVDF/PU composite.However,the conductive carbon black/PVDF/PU composite material does not enhance the damping property of the material.(3)The sheet and tetrapod-like ZnO incorporated into the PVDF/PU matrix,results of IR analysis showed the addition of ZnO whiskers did not affect the formation of PVDF β phase;Dielectric tests show that the dielectric constant of the tetrapod-like ZnO/PVDF/PU composites has the biggest value of the dielectric constant was 34.The ZnO whisker with different morphologies can improve the damping property of the material.Particularly,the effect of tetrapod-like ZnO is better than that of sheet ZnO.And the maximum of tanδ is 0.37,which increased the damping property of the materialIn conclusion,solution method can effectively improve the content of β phase in PVDF.In the case of little influence on the piezoelectric properties of composite materials,PU is the matrix and PVDF is a piezoelectric functional,which can add an energy conversion method.In order to improve the electric properties of composites,conductive carbon black and ZnO with different shapes were incorporated into the PVDF/PU matrix which could effectively improve the dielectric performance of materials.Therefore,piezoelectric damping materials doped with inorganic filler have good comprehensive performance and wide application prospect.