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Plasticization of poly(lactide) with poly(ethylene glycol): Low weight plasticizer vs triblock copolymers. Effect on free volume and barrier properties

In order to make poly(lactide) (PLA) suitable for food packaging applications, its toughness must be improved. In this work, the plasticization effectiveness of a low?molecular?weight plasticizer and a triblock copolymer are analyzed. For this purpose, PLA is blended with poly(ethylene glycol) (PEG) and poly(lactide?ethylene glycol?lactide) (LA?EG?LA) triblock copolymer. The obtained results show that copolymers are more effective, reducing the glass transition temperature of PLA. Although PLA/PEG blends have been widely studied in the literature, the barrier character has not been analyzed, which is of paramount importance for packaging applications. Therefore, the permeability to carbon dioxide, oxygen, and water vapor of PLA/PEG blends has been characterized observing an increase with the incorporation of PEG, which is the expected behavior. However, the incorporation of LA?EG?LA copolymers leads to permeability values that are slightly higher, similar, or even lower than PLA. Furthermore, the free volume of the samples has been analyzed in order to gain a deeper insight on the factors affecting the transport properties. Overall, this works aims to provide a better understanding towards the design of biodegradable packaging with improved properties that could be also extended to other biodegradable polymers. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 137, 48868.

Publication date: 26/12/2019

Author: Ana Chaos, Ainara Sangroniz, Jorge Fernández, Javier Río, Marian Iriarte, Jose Ramon Sarasua, Agustin Etxeberria

Reference: doi:10.1002/app.48868

Journal of Applied Polymer Science


This project has received funding from the Bio Based Industries Joint Undertaking under the European Union’s Horizon 2020 research and innovation programme under grant agreement No 837761.