Tunable temperature-responsive permeable composite films using polyethylene glycol as a phase change material

Poly(ether-block-amide) (PEBAX)/polyethylene glycol (PEG) (PEBAX/PEG) composite films were successfully prepared, via solution casting methods, for use as temperature-responsive permeable composite films. Their morphologies, thermal properties, and permeabilities were investigated as a function of PEG content. The introduction of high molecular weight PEG into PEBAX results in enhancement of thermal stability in the composite films. As the PEG content was increased, water vapor uptake increased, but the vapor diffusion rate decreased because of effects related to chemical affinity and crystallinity. All PEBAX/PEG composite films exhibited a jump in permeability at temperatures near the PEG phase transition temperature, and this depends on PEG content. This indicates that considerable gas passed through the composite films at temperatures near the PEG phase transition temperature, and this can be controlled by introducing different amounts of PEG. Our result can provide the insights into the further development of self-venting materials using temperature-responsive permeable materials for food, agricultural, and biomedical packaging.