Toughening Biodegradable Poly(glycolic acid) with Balanced Mechanical Properties by Biobased Poly(butylene 2,5-furanoate)

Abstract

Poly(glycolic acid) (PGA) possesses widespread interest due to its outstanding degradability as well as mechanical performance, however, its poor toughness restricts their application. In this work, we synthesized biobased poly(butylene 2,5-furanoate) (PBF), then added a small amount by melt extrusion into PGA to achieve a balance between toughness and mechanical properties of PGA. The incorporation of PBF significantly enhanced the tensile toughness and impact toughness of PGA. Specifically, when the PBF content reached 50 wt.%, the blend exhibited a maximum elongation at break (121.2%), which was 18.9 times higher than that of pure PGA. However, owing to no changes observed in terms of chemical structure, crystal structure, and compatibility before and after blending, it can be concluded that the improvement in material toughness is not attributed to any chemical reactions or compatibility alterations between PBF and PGA. Based on the rheological characterization and morphological analysis of SEM, it has been demonstrated that the shape alteration of PBF serves as the primary mechanism for toughening PGA. Due to the excellent barrier properties of PBF, the addition of PBF makes the barrier properties of the blend better maintained. Thus, this work prepares a sustainable PGA/PBF blend with excellent strength and barrier properties via melt-blending method, which show great potentials in high-barrier application scenarios such as food packaging.