Selection of PEG-Matrix Combinations to Achieve High Performance Form-Stable Phase Change Materials for Building Applications

The construction sector's pursuit of sustainability, driven by growing concerns about climate change and resource depletion, requires innovative solutions to reduce the energy consumption necessary to ensure thermal comfort in buildings. The introduction of phase change materials (PCMs) in construction elements represents an effective solution to these problems. PCMs are, in fact, able to regulate internal temperature by storing and releasing thermal energy during their phase transitions. In particular, polyethylene glycol (PEG)-based organic PCMs offer high heat storage capacity, compatibility with building materials, and minimal environmental impact. They are often used in building applications incorporated in an inert matrix, using the "form-stable method". This article critically examines various matrices proposed in the existing literature to realize PEG-based PCMs, with the aim of analyzing their influence on the final characteristics of any PCM. In addition, an attempt to correlate the quantity of PEG with the heat stored and released by the PCM is presented, using a linear regression model applied to groups of matrices of the same chemical nature. The results of these analyses would, in fact, provide useful indications for an optimal choice of the PEG/matrix system capable of responding to specific application needs, particularly in the building sector.