Dual‐Functional Compatibilizers for Fabricating High‐Performance PLLA/PBS Blends With Enhanced Heat Resistance and Ductility

To address the poor interfacial compatibility of poly( l ‐lactide)/polybutylene succinate (PLLA/PBS) blends, in this study, we fabricated PLLA‐g‐PBS and PDLA‐g‐PBS graft copolymers as compatibilizers via a facile and cost‐effective method. The effects of varying concentrations of these graft copolymers on the properties of PLLA/PBS blends were systematically investigated. Results revealed that both compatibilizers significantly enhanced interfacial adhesion. Notably, PDLA‐g‐PBS outperformed PLLA‐g‐PBS by leveraging stereocomplex crystallites (SCs) formation, which simultaneously improved crystallinity and heat resistance. The optimized PDLA‐g‐PBS content compatibilized blends achieved a crystallinity of 21.7% and a Vicat softening temperature of 113.9°C, representing a 46°C enhancement over uncompatibilized blends. These findings offer a scalable strategy to design PLLA‐based blends with balanced mechanical strength, heat resistance, and degradability, holding promise for sustainable packaging and automotive applications.