Thermal characterization of polymer matrix composites containing microencapsulated paraffin in solid or liquid state

•Thermal characterization of PCL/Micronal composites.•Melting enthalpy and heat capacity measured by DSC.•Interest: have measured thermal properties at different temperatures.•Thermophysical properties measurement temperatures chosen outside phase changes.•Characteristics useful to model composites heat transfer for LHTES applications.

This work focuses on the study of heat transfer mechanisms in composites materials which may be used for Latent Heat Thermal Energy Storage applications. These composites contain phase change material (PCM) which can absorb and release energy during thermal cycling. PCM’s used here are paraffins microencapsulated in poly(methylmethacrylate); microencapsulation avoids the flow of paraffin when it is in the liquid state. Samples with different paraffin weight fractions and particles shape and distribution were studied in this work. Scanning Electron Microscopy and Differential Scanning Calorimetry were used to determine morphology and perform measurements of phase changes temperatures, enthalpies and heat capacity respectively. Further, a periodic method (DICO) allowed measuring thermal conductivity (λ) and diffusivity (a) of the composites at temperatures below and above of the paraffin phase change from crystalline solid to isotropic liquid.