Self‐Reinforced <scp>PBAT</scp> Through Dynamic Vulcanization Process for Enhanced Mechanical Properties While Retaining Processability

ABSTRACT To address environmental pollution from non‐degradable plastics, biodegradable poly (butylene adipate‐co‐terephthalate) (PBAT) has been developed but suffers from limited mechanical properties and high cost. This study introduces a self‐reinforcement technique via dynamic vulcanization to enhance PBAT films. A portion of PBAT was first melt‐blended with a multi‐functional epoxy copolymer (ADR) at lower temperature to prevent premature reaction. Subsequently, this blend was further melt‐blended with neat PBAT also by extrusion process, where shear‐induced dispersion and branching reactions occurred simultaneously. This two‐step process ensures the formation of a continuous phase consisting of neat PBAT and a dispersed phase consisting of branched PBAT, forming self‐reinforced PBAT. In contrast, a one‐step control uniformly reacted ADR with all PBAT. Comprehensive characterizations using scanning electron microscopy, atomic force microscopy, mechanical testing, rheological analysis, and thermal property evaluation were performed. The results indicate that the self‐reinforced PBAT film exhibits a higher tensile strength (45.8 MPa) compared to the one‐step process PBAT film (41.2 MPa) and the neat PBAT film (34.3 MPa). Additionally, different from direct blending with ADR, this self‐reinforcement technique maintains the inherent thermoplastic processability of PBAT, implying wide applications in enhancing mechanical performance and lowering the cost of biodegradable film, bag, etc.