Reinforcing tear resistance, tensile strength, and shape-memory behavior of pbat via mannitol-derived hydrogen bonding networks

While biodegradable polyesters such as poly (butylene adipate-co-terephthalate) (PBAT) present a promising alternative to conventional plastics in addressing plastic pollution, their lack of shape-memory functionality and relatively low mechanical strength severely limit practical applications. This study developed D-mannitol modified PBAT copolyesters (PBMAT) with integrated biodegradability and shape-memory functionality through a two-step esterification and one-step polycondensation approach. FTIR, 1 H NMR, DSC, XRD tests combined with changes in hydrophilicity indicate that the incorporation of D-mannitol successfully established a dynamic hydrogen bonding network. When D-mannitol was added at 1.4 wt%, the copolyester exhibited optimal performance: tensile and tear strengths increased by 32.76 % and 35.99 % respectively, accompanied by a 49.22 % enhancement in elongation at break compared to pristine PBAT. Leveraging reversible hydrogen-bond transitions, the 2.8 wt% PBMAT sample achieved an 80.47 % shape recovery rate (55.92 % improvement over PBAT) at 50 ℃ (below melting temperature), with a fixation rate exceeding 80 %. This approach synergistically enhanced mechanical strength and thermal stimulus response properties, advancing the design of smart biodegradable materials.