Bio-based poly(butylene diglycolate-co-furandicarboxylate) copolyesters with balanced mechanical, barrier and biodegradable properties: A prospective substitute for PBAT

• Published in: Polymer degradation and stability Vol. 202; p. 110010
• Main Authors: Dong, Yunxiao, Wang, Jinggang, Yang, Yong, Wang, Qianfeng, Zhang, Xiaoqin, Hu, Han, Zhu, Jin
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2022
• Subjects: 2,5-Furandicarboxylate acid; Bio-based copolyesters; biodegradability; Biodegradation; carbon dioxide; chemical composition; composts; condensation reactions; crystal structure; crystallization; degradation; Diglycolic acid; Gas barrier properties; hydrolysis; hydrophilicity; modulus of elasticity; polyesters; transesterification; 2,5-Furandicarboxylate acid; Diglycolic acid; Biodegradation; Gas barrier properties; Bio-based copolyesters
• ISSN: 0141-3910; 1873-2321
• DOI: 10.1016/j.polymdegradstab.2022.110010

•PBDFs in the full composition range were prepared using bio-based or potential bio-based monomers as raw materials.•Diglycolic acid improves the hydrophilicity of PBDFs, thereby accelerating their degradation rates.•All PBDFs exhibited better gas barrier properties than PBAT.•PBDF40 is a prospective substitute for PBAT for food packaging materials with gas barrier requirements. Poly(butylene adipate-co-terephthalate) (PBAT) is a flexible aliphatic/aromatic copolyester commercialized for degradable plastics, while the slow degradation rates and poor barrier properties limit its applications. Consequently, it is highly desirable to develop materials with faster degradation rates and enhanced barrier properties. Here, we synthesized poly(butylene diglycolate-co-furandicarboxylate) (PBDF) copolyesters by transesterification and melt polycondensation. The NMR spectra confirmed their structure and composition. Besides, the thermal, mechanical, permeable and degradable properties were characterized thoroughly. It was found that the properties were dependent on chemical composition and crystallinity. Actually, the introduction of diglycolic acid (DGA) comonomer hinders the crystallization and all the copolyesters appear as semicrystalline polyesters except for PBDF80. Among them, PBDF40 possesses outstanding mechanical properties with an elastic modulus of 165 MPa, tensile strengths of 54 MPa, and elongations of break of 654%. Moreover, the CO2 and O2 barrier properties of PBDF40 are 68.6 and 45.9 times higher than those of PBAT. PBDFs also exhibit accelerated rates in hydrolysis and composting degradation, which could be attributed to the enhanced hydrophilicity due to the electronegativity of ether-oxygen atoms in DGA. In particular, the mass loss of PBDF40 reaches 46% and 42% after 28 days of CALB enzymatic degradation and 8 weeks of compost degradation, respectively. These results highlight that the synthesized polyesters, especially PBDF40, demonstrate potential application in food packaging.