Toughening modification of poly(lactic acid)/poly(ε-caprolactone) blends by in-situ compatibilization

Styrene – glycidyl acrylate copolymer Joncryl ADR4368 (ADR) was employed as a compatibilizer in the immiscible blends of poly(lactic acid) (PLA) and poly(ε-caprolactone) (PCL). The morphology, crystallization behavior and mechanical properties were investigated. The compatibility between PLA and PCL was poor, thus leading to poor tensile properties for PLA/PCL blends. The addition of ADR reduced the size of PCL domains due to the formation of long chain branched copolymers in the interface, indicating the improved compatibility of PLA and PCL. PCL enhanced the cold crystallization ability of PLA, while ADR delayed the cold crystallization ability of PLA. Compared with PLA/PCL blends, PLA/PCL/ADR obtained a more uniform microcrystalline dispersion during cooling. Therefore, when the PCL content was 30 wt%, the elongation at break and impact strength of PLA/PCL/ADR were effectively improved at 1 wt% ADR.