Preparation and Characterization of Enzymatically-Treated Granular Cassava Starch and Poly(butylene adipate-co-terephthalate) Blends

Raw cassava starch was treated with α-amylase and amyloglucosidase in aqueous solution under annealing condition to obtain starch granules with rough and porous surfaces. Many different pits and pores formed by the activity of the enzymes on the surface granules and were observed by scanning electron microscopy (SEM). The obtained starch granules with rough surfaces were mechanically blended with poly(butylenes adipate-co-terephthalate)(PBAT) at different ratios by using a single screw extruder. The results showed that the samples comprised of enzymatically treated starch blends had higher elongation than those comprised of untreated starch blends. At 10% starch content, the treated starch/PBAT blend had about 37.55% more elongation than the untreated starch/PBAT blend. This resulted in the improved compatibility of the starch granules and PBAT matrix in the blends as confirmed by SEM.