Prediction of the Thermal Conductivity of Polypropylenes and Propylene Copolymers Based on Crystallinity or Elastic Modulus

ABSTRACT Knowledge about the thermal conductivity of propylene‐based materials is important for the development of new dielectric materials. However, many research laboratories do not have access to suitable instrumentation. Here, the thermal conductivity of a series of isotactic and low‐tacticity polypropylenes as well as random, heterophasic and random heterophasic propylene‐based copolymers is characterized. The thermal conductivity of isotropic samples is found to linearly increase from approximately 0.18 W m −1 K −1 for amorphous material to 0.26 W m −1 K −1 for a crystallinity of 60%. At the same time, the Young's modulus exponentially increases from 24 MPa to more than 1700 MPa for the most crystalline materials, which is used to predict a logarithmic increase of the thermal conductivity with Young's modulus. Overall, the results presented here allow us to estimate the thermal conductivity of propylene‐based materials with an uncertainty of about 0.01 W m −1 K −1 through straightforward differential scanning calorimetry or tensile deformation measurements.