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

Artikel i vetenskaplig tidskrift, 2026

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.