Application and method for preparing electret piezoelectric material from head-head connected hydrogenation P (VDF-TrFE)

Abstract

The invention discloses an application and a method for preparing an electret piezoelectric material from head-head connected hydrogenation P (VDF-TrFE). The hydrogenation P (VDF-TrFE) is prepared into a film, an electric field is heated and polarized, a polymer has an unexpected result, namely, the polymer has the advantages of high voltage coefficient and good electromechanical coupling performance and the like; a dipole moment formed by C-F and C-H bonds in a molecular chain is oriented along an electric field direction so that a chain alignment mode similar to TTTT is formed. The head-head connected hydrogenation P (VDF-TrFE) has the characteristics of safe operation, good stability and low raw material noxious property, and the method can greatly reduce the preparation cost of the P (VDF-TrFE); and the hydrogenation P (VDF-TrFE) is utilized to replace the existing PVDF piezoelectricity film and a direct interpolymer P (VDF-TrFE) so as to be used as the electret piezoelectric material, and the preparation cost of the electret piezoelectric material is greatly reduced.

Description

technical field [0001] The invention belongs to the technical field of piezoelectric electrets, and relates to an application and a method for preparing electret piezoelectric materials by head-head-connected hydrogenated P (VDF-TrFE). Background technique [0002] Electret (electret) is a dielectric material that can store space charge and polarized charge for a long time without an external electric field and has a macroscopic electric moment. It has excellent electroacoustic performance and voltage stabilization performance, and is mainly used in microphones. , earphones, speakers, microphones, accelerometers, various transducers, high-voltage power supplies, radioactive dosimeters, etc. In the 1950s and 1960s, Fukada and some other scholars discovered polymer electret materials [H.Kawai.Jpn.J.Appl.Phys.,1969,8:975], according to the polarization mode of electret materials Electrets can be divided into two categories: charge injection type and spontaneous polarization ty...

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Problems solved by technology

However, it should be pointed out that the P(VDF-TrFE) studied above all comes from the copolymerization method, which has the disadvantages of difficulty in obtaining monomers, harsh synthesis process conditions and high cost, so it is difficult to popularize and use

[0004] In recent years, there have been reports of indirect preparation of P(VDF-TrFE) by hydrogenation of vinylidene fluoride and chlorotrifluoroethylene copolymer (P(VDF-CTFE)) [Wang ZM, Zhang ZC, Mike Chung TC.Macromolecules, 2006;39 : 4268], adopted tributyltin hydride and azobisisobutyronitrile as catalyzer in this method, carried out hydrogenation reaction in tetrahydrofuran, but the use of highly toxic organotin compound makes the product obtained difficult to purify

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