Toughened bio-based poly(butylene succinate)/poly(butylene adipate-co-terephthalate)/poly(3-hydroxybutyrate-co-3-hydroxyvalerate) ternary bioplastics for high-performance sustainable packaging

The influence of polymer selection, relative ratios, and hybrid compatibilizer addition on blend properties was systematically investigated. Morphological analysis revealed that the blend components remained largely immiscible, consistent with solubility parameter predictions, while interfacial tension measurements indicated that BioPBS effectively separated PHBV and PBAT phases.

Optimized ternary blends with 50 wt.% PHBV exhibited synergistic mechanical performance, reaching elongation at break close to 100%, tensile strength around 35 MPa, and Young’s modulus exceeding 1.6 GPa. Rheological analysis suggested enhanced interfacial interactions due to increased chain entanglement, even in the absence of a compatibilizer. Incorporation of 3-5 wt.% hybrid compatibilizer further enhanced mechanical and thermal performance, with elongation at break increasing by 8%, impact strength by 15%, and Young’s modulus by 9%, alongside improved thermal stability.