THERMAL STUDIES OF REINFORCED-PLASTIC MATERIALS. PART 2. PROPERTIES OF NINE REINFORCED-PLASTIC LAMINATES

The thermal conductivity and specific heat of nine plastic laminates were experimentally eval uated, whereas the thermal diffusivity of the test materials at 140 F was calculated from its relationship to thermal conductivity, specific heat, and density. Data for evaluating thermal conductivity were obtained by using a guarded hot plate apparatus under steady-state conditions. Values of thermal conductivity were plotted versus temperature, and by the method of least squares an equation was formulated expressing thermal conductivity as a function of tempera ture. The classical method of mixtures was used to evaluate the specific heat of the test mate rials at a mean temperature of 140 F. Along with test results are included recommendations concern ing the thermal conductivity apparatus and the specific heat apparatus used in the tests, and a recommendation for the constructionradiant heat facility for determining thermal diffusivity directly.