What Is an Electret?

Polymer electrets are also called electret compounds. Polymer material with electret function. The polymer electret can be made into a flexible film, and at the same time, it has excellent charge storage capacity and has a promising future. There are two main types. One is a highly insulating material, such as polytetrafluoroethylene and a copolymer of fluoroethylene and propylene, which have a relatively good ability to maintain the injected charge. The other is a polarizable polymer, such as polyvinylidene fluoride. There is a permanent dipole moment in the molecule. After polarization, this material can maintain the directivity of its dipole in a certain temperature range. Often exhibits piezoelectric and thermoelectric properties. Both of these electrets have a wide range of practical uses.

Polymer electrets are polymer dielectric materials that have a dipole orientation and have been polarized for a long time ^[1]

Heating polymer to glass transition in a DC high voltage electric field

Natural polymers such as Brazilian palm wax, polysaccharides, polysaccharides, hard rubber and synthetic polymer polycarbonate, polymethyl methacrylate, polypropylene, copolymers of tetrafluoroethylene and perfluoropropylene can be made Polar body.

Polymer electret materials have been used in microphones, underwater acoustic detectors, powerless phones, electrometers, and air filters.

The preparation methods include electron or ion implantation method, polarization method and stretch polarization molding method, etc. According to different uses, different preparation molding methods can be selected ^[1] .