Accession Number:

AD0706405

Title:

ABLATIVE CHARACTERISTICS OF POLYETHYLENE AND OTHER THERMOPLASTICS

Descriptive Note:

Technical rept.

Corporate Author:

AIR FORCE MATERIALS LAB WRIGHT-PATTERSON AFB OH

Personal Author(s):

Report Date:

1970-03-01

Pagination or Media Count:

41.0

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.

Subject Categories:

  • Plastics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE