Thermo-regulating properties of textiles with incorporated microencapsulated Phase Change Materials

Phase change materials (PCMs) are getting increasing interest due to their capacity to absorb, store and release heat energy. Their effectiveness is characterized by quantities of absorbed/released heat energy, expressed as enthalpy. Specifically, the larger is the enthalpy, the more efficient thermoregulation effect is achieved. With this in mind, PCMs can be used in the manufacture of thermally regulated clothing in order to minimize heat strain and simultaneously improve thermal comfort. Moreover, such materials also modify their infrared radiation emission during phase transition, thus they can be envisioned to exploit thermal shielding applications. The aim of the present research was to investigate the infrared emissivity of textiles composed by cotton yarns with dispersed PCMs. The organic microcapsules of phase change materials, having different binding to the fibre mechanisms, were padded onto the fabric surface by pad-dry-cure method. The thermal properties and stabilities were measured using differential scanning calorimetry, while infrared emissivity was characterized using infrared thermographic technique. The obtained experimental results show a dynamic tuning of IR emissivity during heating/cooling process which can be correlated to the type and properties (enthalpy of fusion) of the corresponding PCM.