Effect of chain extender and light stabilizer on the weathering resistance of PBAT/PLA blend films prepared by extrusion blowing

• Published in: Polymer degradation and stability Vol. 183; p. 109455
• Main Authors: Zhang, Ting, Han, Weiyao, Zhang, Caili, Weng, Yunxuan
• Format: Journal Article
• Language: English
• Published: London Elsevier Ltd 01.01.2021; Elsevier BV
• Subjects: Additives; Artificial weathering; Biodegradability; Biodegradable materials; Blow films; Blowing; Chain extender; Chain scission; Crosslinking; degradation; Elongation; Extrusion; Infrared spectra; Light stabilizer; Melt blending; Melting; PBAT; PLA; Polylactic acid; Polymerization; stabilizers; Tensile strength; Weathering; PBAT; Light stabilizer; Chain extender; PLA; Artificial weathering; Blow films
• ISSN: 0141-3910; 1873-2321
• DOI: 10.1016/j.polymdegradstab.2020.109455

•How the addition of an ADR chain extender affected the weathering resistance of the PBAT/PLA composite films.•Influence of Chimassorb 2020 and Irganox 1010 light stabilizers on the PBAT/PLA film service life.•Better weathering improvement was observed when Chimassorb2020 was added. Biodegradable poly (butylene adipate‑co‑terephthalate)/polylactic acid (PBAT/PLA) films were prepared by melt blending and blowing technology under the presence of a chain extender and two different light stabilizers. A comparison of the infrared spectra of the film with and without these additives before and after the weathering tests showed that the addition of chain extender and light stabilizer improved the polymer weathering resistance significantly. Without PLA, PBAT underwent serious chain scissions and crosslinking during the weathering. PBAT/PLA film chain scissions were weakened as the PLA content increased. After 200 h of the weathering, the machine direction (MD) tensile strength as well as MD and transverse direction (TD) elongation at break of both PBAT and PBAT/PLA films decreased, while their TD tensile strength changed only slightly. The film with the 85:15 PBAT:PLA ratio containing 1.5 phr of chain extender showed much better flexibility without any changes to its tensile strength. The addition of 0.6 phr of light stabilizer (Chimassorb2020 or Irganox 1010) to this blend showed significantly improved weathering resistance. Better weathering improvement was observed when Chimassorb2020 was added. The tensile strength of PBAT/PLA/ADR/ Chimassorb2020 sample in the machine and transverse directions decreased by 8.4 and 28%, respectively, after 200 h of weathering.