Improving the performance of poly(lactic acid)/ <scp>poly(butylene succinate)</scp> blends by compatibilization and reinforcement with nanofibrillated cellulose

Abstract This study investigates the effects of pristine and acetylated nanofibrillated cellulose (NFC) and a poly(lactic acid)‐ co ‐poly(butylene succinate) (PLA‐ co ‐PBS) compatibilizer on PLA/PBS 80/20 blends. Pristine or acetylated NFC (1 wt%) were incorporated into PLA/PBS blends using masterbatches. The impact on morphology, mechanical properties, thermal behavior, crystallization, molecular dynamics, and overall migration using food simulants was examined. SEM revealed improved interfacial adhesion and reduced PBS domain size with the addition of NFC and compatibilizer. Mechanical testing showed that the addition of either NFC or acetylated NFC in PLA/PBS increased tensile strength and Young's modulus, while elongation at break decreased. Differential scanning calorimetry (DSC) and X‐ray diffraction (XRD) analyses indicated changes in crystallization behavior and degree of crystallinity. Dielectric spectroscopy demonstrated alterations in segmental dynamics. Overall migration tests using food simulants suggested suitability for packaging applications with up to 20% alcohol content. The study provides insights into the potential of these fully biobased composite blends for sustainable packaging solutions. Highlights Addition of NFC and compatibilizer improved interfacial adhesion in PLA/PBS blends. Enhanced tensile strength, modulus, and crystallinity are observed with NFC or f‐NFC. DSC and XRD revealed improved nucleation and crystallization in modified blends. Migration tests confirmed suitability for food packaging with up to 20% alcohol content. Findings support fully biobased blends as sustainable packaging materials.