Robust Compatible Blend of Poly(butylene carbonate-co-terephthalate) and Poly(butylene adipate-co-terephthalate) toward a High Barrier Blown Film

Abstract

Poly(butylene adipate-co-terephthalate) (PBAT) is the most frequently used biodegradable packaging material, while poly(butylene carbonate-co-terephthalate) (PBCT) is a recently developed biodegradable copolyester with high barrier and closed-loop recycling performance. In this work, the physical–chemical properties of PBAT/PBCT blends, particularly the barrier performance, and their compatible mechanism have been thoroughly examined. The activation energy calculations and molar weight evolutions showed that PBAT/PBCT blends followed a reactive compatible mechanism. Therefore, when the blending mass ratios were between 40 and 60%, combining PBCT and PBAT improved the tensile strength and elongation at the break concurrently. The cocrystal structure formation was aided by reactive compatibility, as demonstrated by thermal characteristics, crystal structure, and long period scale. Additionally, PBAT chain segment crystallization was facilitated by PBCT acting as the nucleation site. Ultimately, the barrier properties, fruit packaging experiment, and bacterial antiadhesion characteristic all illustrated that PBCT would enhance the use of PBAT in packaging films.