Dependence of the Thermal Conductivity of PMMA, PS and PE on Temperature and Crystallinity

This study presents measurements of the thermal conductivity as a function of temperature for different polymers: poly(methyl methacrylate) (PMMA), polystyrene (PS) and polyethylene (PE). The effects of varying the polymer structure, sample thickness and degree of crystallinity on the thermal conductivity are reported. The thermal conductivity increases with temperature for amorphous and semicrystalline polymers with crystallinity less than 50%, and decreases with temperature for semicrystalline polymers with crystallinity larger than 50%. Moreover, the thermal conductivity of the crystalline polymer is found to be larger than that of the amorphous polymer at the same temperature. The contact resistance of PMMA and PE could be calculated from the sample thickness dependence of the thermal resistance.