Determination of thermal conductivity of moist rigid polymer foams

Abstract

A geometric model of the polymer foam structure was verified taking into account the moisture content of the material and the degree of wetness of the pore surface. Mathematical relations were developed to determine the moisture value at which transition from partial to full wetting of the pore surface occurs and vice versa. A mathematical description of the heat transport process was carried out in the model structure of moist foam taking into account the diffusion of water vapour in the pore space and the nature of wetting of the pore surface. The influence of material porosity, its moisture and water vapour diffusion within the effective porosity on the effective thermal conductivity of the material was determined by calculation. A comparison between the calculation results and experimental data shows their sufficient compatibility.