Synthesis and Characterization of Bio‐Based Poly(Butylene Succinate‐Co‐Sebacate): A Sustainable Alternative to Petroleum‐Based Polyesters

Sustainable, biodegradable polymers are in increasing demand to address the growing environmental concerns associated with plastic waste. Here, bio‐based poly(butylene succinate‐co‐sebacate) (PBSSe) copolyesters are synthesized via two‐step melt polycondensation using succinic and sebacic acids as co‐monomers—with varying molar ratios (10:0, 8:2, 6:4, 4:6, 2:8, and 0:10)—with 1,4‐butanediol. Their chemical structure, thermal behavior, mechanical properties, and biodegradability are systematically investigated. Sebacic acid, a long‐chain aliphatic diacid, improves flexibility, thermal stability, and biodegradability. All PBSSe compositions exhibit a single melting transition and effective degradation under both home‐composting and soil conditions. PBSSe with 20 mol% of sebacic acid exhibits 37% higher tensile strength, 162% higher elongation at break, and superior degradability than commercial poly(butylene succinate‐co‐adipate) (PBSA), while maintaining favorable thermal properties, including a melting temperature of 93°C, T onset of 387°C, and crystallinity of 30%, which are comparable or superior to those of PBSA. Thus, 20 mol% sebacic acid incorporation provides an effective balance between mechanical performance, thermal stability, and biodegradation behavior in poly(butylene succinate)‐based copolyesters. These results highlight the potential of PBSSe 8:2 as a promising bio‐based alternative to petroleum‐derived PBSA for flexible packaging applications requiring superior mechanical performance, thermal resistance, and environmental compatibility.