High Barrier Poly(Glycolic Acid) Modified Poly(Butylene Adipate-co-terephthalate) Blown Films and Accelerated Ultraviolet Degradability Evaluation

The barrier performance and mechanical properties of films play important roles in handling and moisture retention when used in agricultural fields. Herein, poly(butylene adipate-terephthalate)/polyglycolic acid (PBAT/PGA) blending films are prepared by melt-compounding and extrusion-blowing under the presence of antioxidant compounds. The results show that the incorporation of PGA improves the tensile strength, tear resistance, and water vapor barrier property. With the aid of a chain extender, no obvious phase separation and good compatibility are obtained for PBAT/PGA blends. Moreover, antioxidant compounds (1010/AP-618) greatly improve the thermal stability, which is beneficial for thermal processing. Finally, the ultraviolet (UV)-accelerated degradation behavior of PBAT/PGA are investigated. With increasing UV-irradiation days, both the tensile strength and elongation at break of the PBAT/PGA15 (AP) gradually decrease. Also, the characteristic crystalline peaks of PBAT and the initial decomposition temperature of the degraded films progressively decline, suggesting the chain breakages induced by UV irradiation. However, the water vapor barrier permeability is well-maintained due to the high crystallinity of the PGA region, indicating an excellent barrier performance of PBAT/PGA films in the service life. Therefore, the current work proposes high-barrier PBAT/PGA films and explores the photodegradation behavior for the first time, which highlights the great potential as mulching films.