ABLATIVE CHARACTERISTICS OF POLYETHYLENE AND OTHER THERMOPLASTICS
Abstract
The ablative characteristics of polyethylene and four substituted hydrocarbons were examined in arc heated air. The order of increasing penetration rates was polytetrafluoroethylene, a tetrafluoroethylene- hexafluoropropylene copolymer, polychlorotrifluoroethylene, polyethylene, and polyoxymethylene. Penetration rate was related to melting, softening, and viscous flow; molecular structure; sample thickness; secondary reactions; and surface temperature. A polyaminoborane analogy to polyethylene and a tetramethylammonium hydrotriborate derivative of boron hydride underwent penetration at rapid rates. Boron nitride was an efficient conducting heat sink. There was intense, wide-band radiative emission for all three boron-containing, noncharring materials. The major evaluation variables included effluent penetration time, exposure time, heat flux, sample thickness, sample features and surface temperature.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1970
- Accession Number
- AD0706405
Entities
People
- R. W. Farmer
Organizations
- Air Force Research Laboratory