Bio-filler from waste shellfish shell: Preparation, characterization, and its effect on the mechanical properties on polypropylene composites

► Bio-filler for PP composites was prepared from waste shellfish shell. ► Heterogeneous nucleation of PP composites is caused by the shellfish shell bio-filler. ► β-Crystalline phase PP is induced by the shellfish shell bio-filler. ► Mechanical properties of PP composites are improved by adding shellfish shell bio-filler.