Effect of newly developed sintered seashell on the microhardness properties of biocomposites

[Display omitted] •A newly sintered seashell filler was prepared from Mediterranean coasts bio-based seashell.•The structural analysis proved that the composition of SSh is mainly calcium oxide (CaO).•The BET analysis showed that its specific area was significantly increased compared to the raw powder.•The morphological analysis revealed that the sintered SSh exhibit a wing-like morphology.•The addition of SSh biofiller was significant improved the microhardness values of biopolymers. A newly sintered seashell filler (SSh) was prepared from Mediterranean coasts bio-based seashell using a suitable heat-treatment process. The structural analysis proved that the composition of SSh is mainly calcium oxide (CaO) while the BET analysis showed that its specific area was significantly increased compared to the raw powder. In addition, the morphological analysis revealed that the developed SSh exhibit a wing-like morphology, which is the most recommended shape to improve mechanical properties. To evaluate the effect of the elaborated SSh filler on surface microhardness of biopolymers, a series of Vickers microhardness tests were conducted on their extruded biocomposites. By adding 20 wt% of the SSh to poly(butylene succinate), poly(lactic acid), chitin, chitosan, and poly(ɛ-caprolactone), improvements in hardness values of 29.8%, 57.9%, 51.1%, 26.2% and 73.4% were resulted, respectively.