On-demand regulatable mechanical properties of highly transparent biodegradable polymer by dynamic compression training

Biodegradable polymers, especially poly (butylene adipate-co-terephthalate) (PBAT) could be a sustainable alternative to conventional petrochemical plastics if its mechanical properties are considerably reinforced. However, current technologies for reinforcing PBAT require additional components, and the conflicts among degradation, safety, and transparency still need to be overcome. In this work, we proposed a post-treatment method named dynamic compression training (DCT) to regulate the mechanical properties and transparency of pristine PBAT. Through DCT, we are able to regulate the mechanical properties of pre-prepared PBAT film on-demand, in either a more tough manner or a stronger one, which is also highly transparent. The enhancement of mechanical properties results from the increase of hydrogen bond content caused by the enhanced crystallinity, and the orientation of molecular chains. To the best of our knowledge, this is the first report that can make PBAT an ultra-strong, super-tough and highly transparent biodegradable polymer, which surpasses all other biodegradable competitors. Meanwhile, the barrier property is also improved, originating from the densified chain packing and the closer arrangement of crystalline and amorphous regions. This work not only promotes the sustainable development of PBAT with excellent mechanical and transparency properties but also provides meaningful guidance for the on-demand regulatable design of polymer properties.