Bio-based PFA polymer: Achieving high toughness of polylactic acid (PLA) via copolymerization with poly(pentanediol...

Polylactic acid (PLA) is an ideal bio-based biodegradable polymer; however, its application is limited by its brittleness. To broaden the application fields of PLA, modification is necessary. In this study, a series of PLA-poly (furan dicarboxylic acid pentanediol ester) copolyester (PFA)were prepared by copolymerizing PLA with bio-based 2,5-furandicarboxylic acid-based copolyester and pentanediol. The performance changes of PFA were systematically studied from the perspectives of structure, surface morphology, thermal properties, and mechanical properties. The results confirmed that the reaction between the raw materials involved an esterification reaction. As the content of PLA increased, the glass transition temperature of PFA gradually decreased, while the transparency, hydrophobicity, and water vapor transmission rate of films obtained by PFA improved. This method has significant advantages in enhancing the toughness of PLA. The introduction of PPeF altered the crystallinity of PLA, endowing PFA with improved toughness. The maximum elongation at break of the resulting copolymer reached 257.51 ± 15.61 %, which is significantly higher than that of other toughening methods. Based on these characteristics, this bio-based polyester, PFA, has the potential to become an ideal food packaging material.