Screening and Scale-Up\nModifications of PBAT Copolymer\nwith Enhanced Barrier Properties by Incorporation of DMC

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