title: Thermoplastic starch/polyester films: effects of extrusion process and poly (lactic acid) addition.
abstract: Biodegradable films were produced using the blown extrusion method from blends that contained cassava thermoplastic starch (TPS), poly(butylene adipate-co-terephthalate) (PBAT) and poly(lactic acid) (PLA) with two different extrusion processes. The choice of extrusion process did not have a significant effect on the mechanical properties, water vapor permeability (WVP) or viscoelasticity of the films, but the addition of PLA decreased the elongation, blow-up ratio (BUR) and opacity and increased the elastic modulus, tensile strength and viscoelastic parameters of the films. The films with 20% PLA exhibited a lower WVP due to the hydrophobic nature of this polymer. Morphological analyses revealed the incompatibility between the polymers used.
authors.affiliation: Department of Food Science and Technology, Universidade Estadual de Londrina, Rodovia Celso Garcia Cid (PR 445), km 380, PO Box 10011, CEP 86057-970, Londrina, PR, Brazil. marianneshirai@utfpr.edu.br
authors.forename: Marianne Ayumi
authors.initials: MA
authors.lastname: Shirai
authors.forename: Juliana Bonametti
authors.initials: JB
authors.lastname: Olivato
authors.forename: Patrícia Salomão
authors.initials: PS
authors.lastname: Garcia
authors.forename: Carmen Maria Olivera
authors.initials: CM
authors.lastname: Müller
authors.forename: Maria Victória Eiras
authors.initials: MV
authors.lastname: Grossmann
authors.forename: Fabio
authors.initials: F
authors.lastname: Yamashita
mesh_terms: D004548:Elasticity; D006813:Humidity; D019344:Lactic Acid / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D010539:Permeability; D011091:Polyesters / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D013213:Starch / Q000737:chemistry*; D013227:Steam; D013696:Temperature; D014783:Viscosity
chemical_list: D011091:Polyesters; D011108:Polymers; D013227:Steam; C488797:poly(butylene adipate-co-butylene terephthalate); D019344:Lactic Acid; C033616:poly(lactide); D013213:Starch
keywords: Biodegradable film; Blown extrusion; Mechanical properties; Viscoelasticity; Water vapor permeability