Ductile polylactic acid-based blend derived from bio-based poly(butylene adipate-co-butylene furandicarboxylate)

Polylactic acid (PLA) is a kind of bio-based and biodegradable polyester and has shown promise in a variety of fields, but its wider application is limited due to its brittle property. Therefore, in order to improve the ductility of PLA, we synthesized bio-based and biodegradable poly(butylene adipate-copolybutylene furandicarboxylate) (PBAF70) and blended with PLA. The blend's structure, mechanical properties, thermal properties, crystallization properties, and rheological properties were characterized. The results reveal that when the amount of PBAF70 varies from 0 to 30 wt%, the elongation at break increases from 5.7 to 222%, indicating that PBAF70 enhanced the ductility of PLA. At the same time, XRD results showed that stretching-induced crystallization occurred in PBAF70 during the stretching process. The strongly electronegative oxygen atoms in the furan ring may increase the interaction and the compatibility between PBAF70 and PLA. Therefore, the glass transition temperature of PBAF70 is not obvious in the DSC curves of the blends, and the rheological results show that the complex viscosity of the blends is greater than that of PLA. Due to the addition of PBAF70, PLA can only crystallize at a higher temperature, and the addition of PBAF70 hinders the cold crystallization of PLA. It can be seen from SEM that the cross section of the blend is rough, while the PLA is smooth. When the amount of PBAF70 was the same as that of PBAT, the elongation at break of PLA/PBAF70 was better than PLA/PBAT.