Thermal conductivity measurements have been carried out on Polypenco 101 and
Comco brands of nylon 66 (polyhexamethylene adiapamide) rods along the direction of extrusion. The temperature range covered was 1.2 to 350 K, Below 20 K our date (estimated uncertainty + 2%), together with all known published data, conforms to the expression X = 0.00193T 1"30 W m -1 K" 1 to within 10%. Radiative effects above 100 K were demonstrated by performing measurements with and without batting; at 300 K there was a 50% difference between the two sets of data. It is concluded that other radiative effects are present besides direct losses of heat. An increase in the slope of the conductivity versus temperature curve was observed for both samples at the brittleness temperature (T B = 188 K) and a value of Xma x = 0.371 VV m" IIC" I was obtained at the glass transition temperature Ta~-330 K. Above 200 K, X is nearly independent of temperature. A value of O. 365 W m-1 ~(-1 + 3% was found at 300 K, which is about 25% greater than values obtained previously by radial measurements. Anisotropy is a probable cause of this difference. Thermal conductivity integrals have been constructed from the t~ata.