Biopolymers based on copolyester and modified banana starch: property approach

Abstract

Aliphatic–aromatic copolyester/oxidized starch blends were formulated using different copolyester proportions and a constant starch–plasticizer ratio. After homogeneity evaluation, the samples were subjected to mechanical and thermal analyses. Subsequently, biodegradability evaluation under sandy loam garden soil was performed. The results showed that tensile strength, Young’s modulus and elongation at break presented a proportional increase with copolyester content. Differential scanning calorimetry analysis evidenced that the blend composition has no important influence on the glass transition temperature. The biodegradability tests showed a proportional relation between the amount of modified starch in the formulations and their degradation. Moreover, samples with a higher mass loss exhibited greater color changes, which indicate the microorganisms’ activity.