Compatibilized polylactide/poly(pentamethylene furanoate) blends for fully bioderived packaging films with enhanced fracture toughness and UV- and O2-barrier properties
Giulia Fredi,
Davide Perin,
Carlotta Zardo,
Marco Rapisarda,
Paola Rizzarelli,
Michelina Soccio,
Nadia Lotti,
Andrea Dorigato
Affiliations
Giulia Fredi
Department of Industrial Engineering and INSTM Research Unit, University of Trento, Via Sommarive 9, 38123, Trento, Italy; Corresponding author.
Davide Perin
Department of Industrial Engineering and INSTM Research Unit, University of Trento, Via Sommarive 9, 38123, Trento, Italy
Carlotta Zardo
Department of Industrial Engineering and INSTM Research Unit, University of Trento, Via Sommarive 9, 38123, Trento, Italy
Marco Rapisarda
Institute for Polymers, Composites and Biomaterials (IPCB) – Catania, Via P. Gaifami 18, 95126, Catania, Italy
Paola Rizzarelli
Institute for Polymers, Composites and Biomaterials (IPCB) – Catania, Via P. Gaifami 18, 95126, Catania, Italy
Michelina Soccio
Department of Civil, Chemical, Environmental and Materials Engineering, University of Bologna, Via Terracini 28, Bologna, 40131, Italy; Interdepartmental Center for Industrial Research on Advanced Applications in Mechanical Engineering and Materials Technology, CIRI-MAM, Viale del Risorgimento 2, 40136, Bologna, Italy; Interdepartmental Center for Industrial Research on Buildings and Construction CIRI-EC, Via del Lazzaretto 15/5, 40131, Bologna, Italy
Nadia Lotti
Department of Civil, Chemical, Environmental and Materials Engineering, University of Bologna, Via Terracini 28, Bologna, 40131, Italy; Interdepartmental Center for Industrial Research on Advanced Applications in Mechanical Engineering and Materials Technology, CIRI-MAM, Viale del Risorgimento 2, 40136, Bologna, Italy; Interdepartmental Center for Industrial Agro-Food Research, CIRI-AGRO, Via Quinto Bucci 336, 47521, Cesena, Italy
Andrea Dorigato
Department of Industrial Engineering and INSTM Research Unit, University of Trento, Via Sommarive 9, 38123, Trento, Italy
Polylactide (PLA) is a promising biopolymer from renewable resources but its brittleness and poor gas barrier properties limit flexible packaging applications. Therefore, in this work PLA was blended with a biobased rubbery poly(pentamethylene furanoate) (PPeF), acting as a toughening agent, and a commercial epoxy-functionalized compatibilizer (i.e., Joncryl® ADR-4468) was added to improve the interfacial interaction. The effect of PPeF loading (1–30 wt %) on phase morphology, mechanical properties, oxygen permeability, and degradability in compost was characterized. All blends displayed a sea-island morphology with refined PPeF domains upon compatibilization. Incorporating PPeF induced major tensile ductility enhancements from 5 % strain at break for neat PLA up to 200 % for the blend with 30 wt % PPeF, accompanied by progressive stiffness and strength declines. Through the application of the essential work of fracture (EWF) approach on the prepared films, the specific essential work of fracture (we) was seen climbing from 6.2 to 40.0 kJ/m2 with rising PPeF content, confirming its effectiveness as a toughness enhancer. PPeF contributed to increase the UV- and gas barrier properties of PLA. For example, the oxygen permeability dropped by 37 % for the blend with 30 wt % PPeF. Moreover, compost burial tests also revealed 26 % weight loss of PPeF after 60 days, proving its biodegradability. Hence, finely dispersed PPeF domains induced synergistic property improvements, making PLA/PPeF blends a promising sustainable option for flexible and biodegradable packaging.
