Thermal conductivity, heat capacity, and compressibility of atactic poly(propylene) under high pressure

• The thermal conductivity λ and the heat capacity per unit volume of atactic poly(propylene) have been measured in the temperature range 90–420 K at pressures up to 1.5 GPa using the transient hot-wire method. The bulk modulus has been measured in the range 200–295 K and up to 0.7 GPa. These data were used to calculate the volume dependence of λ, g=−[∂λ/λ)/(∂V/V)]T, which yielded the following values for the glassy state (T<256 K at atmospheric pressure): 3.80±0.19 at 200 K, 3.74±0.19 at 225 K, 3.90±0.20 at 250 K, 3.77±0.19 at 271 K, and 3.73±0.19 at 297 K. The resultant value for g of the liquid state was 3.61±0.15 at 297 K. Values for g which are calculated at 295 K, using theoretical models of λ(T), agree to within 12% with the experimental value for the glassy state.

Ämnesord

NATURVETENSKAP  -- Fysik -- Den kondenserade materiens fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Condensed Matter Physics (hsv//eng)

Nyckelord

Thermal conductivity

specific heat

heat capacity

high pressure

poly(propylene)

atactic

glassy state

liquid

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