Addition of nucleating agent helped in formation of a larger
number of smaller cells in foams. Talc is generally used in starchbased
foam systems. It acted as an effective inorganic nucleating
agent providing nucleation sites for the vaporization of water as
the viscose melt exited the extrusion die. With increasing the talc
content, the cell size became smaller and cell size distribution
became narrower i.e. the uniformity of extruded foam structures
is enhanced [7,8]. As a result, the extruded foams with addition
of talc can normally be less expanded and, therefore, possess
higher density (Table 2). Nonetheless, at too high talc content, such
as in the starch/PLA blend extruded with 3% talc, partial bloating
was observed and cell size distribution turned broader at last