Fig. 3. SEM micrographs of (A) TPS-fracture surface; (B) TPC-fracture surface; (C) TC5-fracture surface; (D) TC10-fracture surface; (E) TC5-film surface; (F) TC10-film surface.The pure starch film (Fig. 3A) showed the cross-section showed the absence of starch granules after processing, demonstrating the extrusion process completely destructurized the native cornstarch granules. These observations are consistent with the results of X-ray diffraction. The same behavior was observed to thermoplastic chitosan (Fig. 3B). However, there are small surface cracks, which may have been formed during the compression-molding step after the extruded films were formed as a consequence of the brittle nature of chitosan.