  Microparticles including paraffin are currently used for textiles coating in
order to deaden thermal shocks. We will show that polymer nanoparticles
embedded in those microsized capsules allow for decreasing the thermal
conductivity of the coating and enhance the protection in the stationary
regime. A reasonable volume fraction of polymer nanoparticles reduces the
conductivity more than predicted by Maxwell mixing rules. Besides, measurements
prove that the polymer nanoparticles do not affect the latent heat and even
improve the phase change behaviour as well as the mechanical properties.

Materials Science