Screening and Scale-Up Modifications of PBAT Copolymer with Enhanced Barrier Properties by Incorporation of DMC

Poly(butylene adipate-co-terephthalate) (PBAT) copolyesters are indispensable components of degradable plastics, but their relatively low strength and barrier properties hamper their applications in daily life. Herein, poly(butylene adipate-co-carbonate-co-terephthalate) (PBACT) copolymers with different butylene adipate/butylene carbonate (A/C) content ratios were prepared by adding dimethyl carbonate (DMC) as the fourth monomer based on melt polycondensation. Specifically, the aromatic unit butylene terephthalate was fixed at 50% molar content, while the aliphatic unit consisting of butylene adipate (BA) and butylene carbonate (BC) units varied. The designed copolyesters maintained high toughness (>700%) and low glass transition temperature (<−13 °C). More appealingly, the insertion of DMC unit endowed the copolyester with a superior barrier performance. Considering its potential commercial feasibility, the PBACT copolyester was a preliminary scale-up prepared in a 5 L steel polymerization reactor, and the kilogram-scale PBACT material was subsequently blown into a high-performance film. It provides new insights into the modifications of PBAT copolyesters with a high barrier performance by incorporation of DMC.