Bio-Based Polymers for Environmentally Friendly Phase Change Materials

Phase change materials (PCMs) have received increasing attention in recent years as they enable the storage of thermal energy in the form of sensible and latent heat, and they are used in advanced technical solutions for the conservation of sustainable and waste energy. Importantly, most of the currently applied PCMs are produced from non-renewable sources and their carbon footprint is associated with some environmental impact. However, novel PCMs can also be designed and fabricated using green materials without or with a slight impact on the environment. In this work, the current state of knowledge on the bio-based polymers in PCM applications is described. Bio-based polymers can be applied as phase-change materials, as well as for PCMs encapsulation and shape stabilization, such as cellulose and its derivatives, chitosan, lignin, gelatin, and starch. Vast attention has been paid to evaluation of properties of the final PCMs and their application potential in various sectors. Novel strategies for improving their thermal energy storage characteristics, as well as to impart multifunctional features, have been presented. It is also discussed how bio-based polymers can extend in future the potential of new environmentally-safe PCMs in various industrial fields.