Plasticization of poly(lactide) with poly(ethylene glycol): Low weight plasticizer vs triblock copolymers. Effect on free volume and barrier properties. - Chaos, Ana; Sangroniz, Ainara; Fernández, Jorge; Río, Javier; Iriarte, Marian; Sarasua, Jose Ramon; Etxeberria, Agustin (Journal of Applied Polymer Science, 2020)