Effect of different UV absorbers on the aging performance of poly (butylene adipate‐co‐terephthalate)/poly (propylene carbonate) degradable mulch films

Abstract Biodegradable agricultural mulch films composed of poly (butylene adipate‐co‐terephthalate) (PBAT) and poly (propylene carbonate) (PPC) were manufactured using the extrusion technique. Integrated three types of UV absorbers C81, UV‐944, and UV‐326. The PBAT and PBAT/PPC mulch films acted as control samples. Preliminary performance assessments indicated that incorporating PPC significantly enhances the tensile strength of the PBAT mulch film. Notably, C81 increased the absorbance capacity of the PBAT/PPC mulch film within the 315~350 nm spectrum, whereas both C81 and UV‐944 improved the light transmittance characteristics of the mulch film. After 21‐day UV aging text, the tensile strength of the mulch films containing C81 and UV‐944 surpassed 15 MPa, with elongation at break exceeding 300%. This suggests that C81 and UV‐944 enhance the ultraviolet resistance of the mulch films. Furthermore, following 21‐day artificial climate aging test, the tensile strength of the PBAT/PPC mulch film with C81 also exceeded 15 MPa, showcasing not only exceptional UV resistance but also the ability to mitigate effects from artificial climate aging. SEM indicated that the ultraviolet absorbers hinder the aging process of the mulch films by minimizing the generation of flaky materials, thus safeguarding the mechanical integrity of the PBAT/PPC film. Highlights UV absorbers enhance the mechanical properties of the PBAT/PPC mulch films after aging. C81 increased the absorbance capacity of the PBAT/PPC mulch film. The PBAT/PPC mulch film containing C81 exhibits the best performance.