Enhancing Polylactic Acid Properties by Blending With Recycled Polycarbonate: The Effect of a Bio‐Based Compatibilizer on Properties

ABSTRACT This study explores enhancing polylactic acid (PLA) by blending it with recycled polycarbonate (r‐PC) to improve its brittleness and thermal limitations. Recycled r‐PC, obtained from compact discs, was mixed with PLA in varying ratios (100:0 to 0:100), using epoxidized soybean oil (ESO) and a chain extender (CE) as bio‐based compatibilizers. Scanning electron microscopy revealed smoother fracture surfaces with ESO, indicating improved compatibility. Mechanical testing showed significant toughness enhancement, with the 30PLA70r‐PC blend reaching 8725 kJ/m 3 —nearly ten times that of pure PLA. ESO raised tensile strength from 47.39 MPa to 52.57 MPa, while CE increased elongation at break to 32.14%. Differential scanning calorimetry indicated reduced PLA crystallinity, dropping from 68.17% to 10.32% with increasing r‐PC. A new thermal transition at 225°C in ESO‐rich blends suggested enhanced molecular interactions. X‐ray diffraction showed a shift toward an amorphous structure at higher r‐PC contents. Dynamic mechanical thermal analysis revealed improved thermal stability, with glass transition temperature rising from 61°C (PLA) to 141°C in r‐PC‐rich blends. These findings demonstrate that combining biodegradable PLA with r‐PC and ESO produces high‐performance, sustainable composites suitable for circular economy applications.