4 research outputs found
Polyethylene glycol/polylactic acid block coâpolymers as solidâsolid phase change materials
Abstract Phase change materials (PCMs) are promising thermal energy storage materials due to their high specific latent heat. Conventional PCMs typically exploit the solidâliquid (sâl) transition. However, leakage and leaching are common issues for solidâliquid PCMs, which have to be addressed before usage in practical applications. In contrast, solidâsolid (sâs) PCMs would naturally overcome these issues due to their inherent form stability and homogeneity. In this study, we report a new type of sâs PCM based on chemically linked polyethylene glycol (PEG, the PCM portion) with polylactic acid (PLA, the support portion) in the form of a block coâpolymer. Solidâsolid latent heat of up to 56âJ/g could be achieved, with melting points of between 44â°C and 55â°C. For comparison, PEG was physically mixed into a PLA matrix to form a PEG:PLA composite. However, the composite material saw leakage of up to 9% upon heating, with a corresponding loss in thermal storage capacity. In contrast, the mPEG/PLA block coâpolymers were found to be completely homogeneous and thermally stable even when heated above its phase transition temperature, with no observable leakage, demonstrating the superiority of chemical linking strategies in ensuring form stability