Poly(lactic‐co‐glycolic acid)‐Based Biodegradable Thermoplastic Elastomers: Tunable Mechanical and Degradation Properties

Poly(lactic‐co‐glycolic acid) (PLGA) is a widely used biodegradable polyester; however, its inherently glassy nature limits its applicability in systems requiring large and reversible deformation. In this work, segmented PLGA‐based biodegradable thermoplastic elastomers (BTPE PLGA ) were developed by incorporating highly flexible, amorphous aliphatic polyester soft segments with a low glass transition temperature (≈−55°C) through chain extension with hexamethylene diisocyanate (HDI). The resulting materials exhibit microphase‐separated morphologies characterized by distinct glass transitions associated with soft‐ and PLGA‐rich domains. By varying the PLGA/soft‐segment ratio, mechanical properties can be systematically tuned, with tensile strengths ranging from approximately 5 to 15 MPa and elongations at break exceeding 900% at intermediate compositions. Cyclic tensile tests demonstrate elastic recovery above 90% under repeated loading. Dynamic mechanical analysis reveals composition‐dependent modulus and a stable rubbery plateau region. Enzymatic degradation studies further show that the mass‐loss behavior can be regulated through segmental composition while maintaining the thermoplastic elastomer characteristics. These results demonstrate that segmented structural design provides an effective strategy for balancing elasticity and degradation behavior in PLGA‐based thermoplastic elastomers.