Highly Enhanced Mechanical Strength and Toughness of Biodegradable PBAT Plastics through a Biobased Multiple Hydrogen Bonding Strategy

Poly(butyleneadipate-co-terephthalate) (PBAT), a favorable biodegradable polyester, exhibits striking application potential as a sustainable alternative of conventional petrochemical plastics to relieve the problems on environmental pollution. However, the utilization of PBAT materials is still limited due to their suboptimal strength and toughness. Here, we utilized melting chain extension reaction to incorporate multiple hydrogen bonding units into the main chain of PBAT, achieving the great enhancement in mechanical strength and toughness of the PBAT plastics. Melting copolymerization between the low-molecular-weighted (MW) PBAT and the biobased isocyanate- and carbon dioxide-derived bis(hydroxyalkyl carbamate) displays high effectivity and scalability, and the copolymerized PBAT presents highly enhanced mechanical performance (strength high up to 52 MPa, elongation at break >1500%, and fracture toughness high up to 583 MJ/m3) much better than the commercial available high-MW PBAT and its composites, emphasizing its great potential to broaden the use of biodegradable PBAT in plastic products. We investigated the influence of the hard segment content on the mechanical and rheological behaviors and revealed the strengthening and toughening mechanisms. This work provides insights and scalable strategies for the development of high-performance biodegradable polyesters.