Accession Number : ADA310381

Title :   Thermal Conductivity of Selected Foams and Systems from 100 to 300 K.

Descriptive Note : Final rept. May-Jul 86,

Corporate Author : NATIONAL BUREAU OF STANDARDS GAITHERSBURG MD

Personal Author(s) : Sparks, L. L. ; Dube, W. P. ; Slifka, A. J.

PDF Url : ADA310381

Report Date : JAN 1988

Pagination or Media Count : 56

Abstract : The apparent thermal conductivity of five insulating materials was determined in the nominal temperature range from 100 to 300 K (-280 to 80 deg F). A guarded hot plate apparatus was used and the testing environment was dry nitrogen gas at near ambient pressure. One specimen was retested in a vacuum environment. Three of the specimens were neat polymethacrylimide (PMA) foams with nominal densities of 51 and 71 kg/m3 (3.2 and 4.4 lb/ft3). Other specimens tested were a polyurethane foam sprayed on an aluminum substrate and a sandwich construction specimen utilizing PMA foam of nominal density 110 kg/m3 (6.9 lb/ft3). The results in nitrogen gas show the expected conductivity increase with increasing density. The observed conductivity at 0.67 Pa (5 micrometers of Hg) is significantly lower than that in ambient pressure nitrogen gas. The large relative difference may be due to increased thermal resistance at the plate specimen boundaries.

Descriptors :   *THERMAL CONDUCTIVITY, *EXPANDED PLASTICS, TEST AND EVALUATION, SPACE ENVIRONMENTS, INSULATION, NITROGEN, RANGE(EXTREMES), POLYURETHANE RESINS, AIR PRESSURE, THERMAL RESISTANCE.

Subject Categories : Thermodynamics
      Plastics

Distribution Statement : APPROVED FOR PUBLIC RELEASE