Río Esteban, Francisco Javier DelChaos, AnaSangroniz, AinaraGonzález, AlbaIriarte, MariamSarasua, José RamónEtxeberria, Agustín2023-06-172023-06-172019-010959-810310.1002/pi.5705https://hdl.handle.net/20.500.14352/13019©2019 Wiley The authors are grateful for funds from the Basque Government (IT-618-13 and IT-927-16), University of the Basque Country (UFI 11/56) and the Spanish Ministry of Science and Competitiveness MINECO (MAT-2016-78527-P). AS acknowledges the Basque Government for a PhD grant.The effectiveness of tributyl citrate (TbC) as a plasticizer for polylactide and polyhydroxybutyrate was analysed in order to improve the ductility of these polymers and make them good candidates for food packaging applications. Although the thermal and mechanical properties have been widely studied in the literature, the effect of the plasticizer on free volume and transport properties has not been deeply analysed. The free volume was characterized using positron annihilation lifetime spectroscopy observing its linear increase with TbC content. The permeability to water vapour, oxygen and carbon dioxide was determined and the obtained results were related to the changes in glass transition temperature, level of crystallinity of the samples and free volume. This work would allow a better understanding of the effect of the plasticizer on the barrier and mechanical properties of polymers allowing the development of competitive materials for packaging applications. (c) 2018 Society of Chemical Industryengjournal articlehttp://dx.doi.org/10.1002/pi.5705https://onlinelibrary.wiley.comopen access538.9Oxygen barrier propertiesPoly(lactic acid)Molecular-weightCarbon-dioxideWater-vaporPoly(3-hydroxybutyrate)SorptionPoly(l-lactide)PermeabilityTemperatureBiodegradable polymerPlasticizerFree volumeTransport propertiesPackagingFísica de materialesFísica del estado sólido2211 Física del Estado Sólido