Controlling Temporally and Spatially Homogeneous Temperature Distribution of Paper Substrates by Biogenic Phase Change Hybrid Material Coatings

Abstract Here the performance of phase change material (PCM)‐coated paper made from unbleached kraft pulp is introduced. The applied PCM consists of a mixture of ethylene glycol distearate (EGDS), a well‐known PCM wax material, and a fully substituted cellulose stearoyl ester (CSE). Transfer of the PCM material onto/into paper is achieved by spray as well as blade coating of EGDS + CSE mixture. It is shown that the kind of coating method used does not interfere with observed PCM properties. The significantly higher melt viscosity of the EGDS + CSE blends ensures that the EGDS wax is not bleeding out of the paper, which avoids the use of further encapsulation processes. The PCM behavior, as observed by thermal load measurements, and the thermal buffering of the coated paper is a function of the applied mass of the PCM material applied. The thermal retention exhibited a quasi‐isothermal behavior at ≈65 °C with EGDS + CSE coatings. These effects can offset fluctuations in temperature, and the PCM papers can be employed to achieve a more uniform temperature setting. PCM‐modified papers are therefore interesting candidates for paper‐based packaging or for use in paper‐based sensors, where overheating can strongly affect reliability of results.