Adhesion and micromechanical deformation processes in PLA/CaSO4 composites

► We study the properties as well as deformation and failure characteristics of bio-composites. ► PLA/CaSO4 composites were prepared from uncoated and stearic acid coated fillers. ► Adhesion is stronger in composites prepared with the uncoated particles. ► The final properties depend unambiguously on the micromechanical deformations. ► Stearic acid seems to dissolve in the polymer and locally change its properties.