Measurement of the thermal conductivity of polymer composites to high temperatures using the line source technique

The line source technique for determination of thermal conductivity has been modified to allow measurement to higher temperatures than previously attained. This required the addition of a high‐temperature tube furnace to the standard experimental equipment. The modified device was used to measure the temperature‐dependent thermal conductivities of a glass‐ and talc‐filled phenol‐formaldehyde(phenolic) resin and a glass‐ and fiberglass‐filled acrylonitrile‐butadiene (AB) copolymer. Thermal conductivities of the virgin material were measured from room temperature to the onset of thermal decomposition. The char material thermal conductivities were measured from room temperature to approximately 900°C. A least‐squares fit of the data yielded a linear‐curve fit for the virgin material and a third‐order fit for the char material.