Citric acid as multifunctional agent in blowing films of starch/PBAT

Citric acid was used as a compatibilizer in the production of starch and PBAT films plasticized with glycerol and processed by blow extrusion. Films produced were characterized by WVP, mechanical properties, FT-IR-ATR and SEM. WPV ranged from 3.71 to 12.73×10-11 g m-1 s-1 Pa-1, while tensile strength and elongation at break ranged from 1.81 to 7.15 MPa and from 8.61 to 23.63%, respectively. Increasing the citric acid concentration improved WVP and slightly decreased film resistance and elongation. The films micrographs revealed a more homogeneous material with the addition of citric acid. However, the infrared spectra revealed little about cross-linking esterification reaction