Transforming fish scale waste into an efficient filler for starch foam.

In this work modified fish scale waste (FS) was used as a filler in order to improve the properties of starch foam prepared by a baking process. The FS was modified under two calcination conditions: at 500 °C for 5 h and at 700 °C for 3 h. The FS powder calcined at 700 °C for 3 h (FS700-3) had higher Ca content and lower protein content and was the filler chosen for experimental study of the effects of its addition on the properties of the starch foam. The addition of FS700-3 to the starch foam produced a more expanded structure due to FS700-3 efficiently supported the growth of existing cells during nucleation and bubble growth. Moreover, the flexural stress at maximum load of the starch foam increased from 1.03 MPa to 1.54 MPa after adding FS700-3 at 10 wt% because of the good adhesion between the two components.