| Abstract: | Polyurethane composites filled with alumina or carbon fibers were prepared to study the thermal conductivities and dielectric properties of polymer composites under humid environments. The thermal conductivities of these polymer composites in relation to filler concentrations and filler sizes were investigated and it was found that the thermal conductivities can increase up to 50 times that of pure polyurethane. The results were analyzed using Agari's model to explain the intrinsic reasons to affect the thermal conductivities of composites. The dielectric loss of these polymer composites were also measured to estimate the influence of moisture under various humid environments. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 2733–2738, 1997 |
