Toughening of polylactide by tailoring phase-morphology with P[CL-co-LA] random copolyesters as biodegradable impact modifiers

► Design of high impact PLA-based materials using partially miscible impact modifiers. ► Affinity of P[CL-co-LA] copolyester towards PLA matrix was investigated on toughness. ► Dependence between toughness improvement and morphology of the resulting blends. ► Dispersion of P[CL-co-LA] copolymers provided a fourfold increase in impact strength. ► Appearance of ribbon-like rubbery microdomains controls the mechanical performances.