Polypyrrole, Formation and Use
Abstract
Radar absorbing materials require resistive or magnetic materials that will convert the electromagnetic energy into heat. The electrical properties of polypyrrole make it a suitable candidate for a radar absorbing material. There are several simple ways to make the polymer with controlled conductivity, and many strategies to process it into a robust material. Interesting materials include polypyrrole-paint, polypyrrole-polyvinylchloride injection moulded composites and polypyrrole coated fabrics and fibres. The highest imaginary component of the permittivity for a polypyrrole composite occurs at the percolation threshold. This is also the region where the permittivity changes rapidly with the amount polypyrrole in the composite and so a high degree of control is required for reproducible making the same formulation. At the conductivities required for microwave absorption, the dc conductivity dominates and the ac component is negligible. Polypyrrole stability is an issue for fabricating a radar absorber, and stability can be improved through a barrier protecting the polypyrrole from oxygen. In this paper many aspects of the formulation and characterisation of polypyrrole materials are considered with an emphasis on its suitability as a microwave absorber.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2005
- Accession Number
- ADA436284
Entities
People
- Paul Saville
Organizations
- Defence Research and Development Canada