Properties of extruded xanthan-starch-clay nanocomposite films

• Autor(a) principal: Melo,Cristina de
• Data de Publicação: 2011
• Outros Autores: Garcia,Patrícia Salomão, Grossmann,Maria Victória Eiras, Yamashita,Fábio, Dall'Antônia,Luiz Henrique, Mali,Suzana
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Brazilian Archives of Biology and Technology
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132011000600019
• topic: film blowing; cassava starch; microstructure; mechanical properties; water vapor permeability

The aim of this work was to manufacture the biodegradable nanocomposite films by extrusion from different combinations of cassava starch, xanthan gum and nanoclays (sodium montmorillonite - MMT- Na) and to characterize them according to their microstructure, optical, mechanical and barrier properties. Films were manufactured from nine starch/xanthan/nanoclay combinations, containing glycerol as plasticizer. Scanning electron microscopy (SEM) of the starch-xanthan extruded films showed reticulated surface and smooth interior, indicating that the gum was mostly concentrated on the surface of the films, while starch/xanthan/nanoclays films showed a more homogeneous surface, suggesting that the introduction of nanoclays provided a better biopolymeric interaction. In general, nanoclays addition (2.5 - 5.0, w%) generated more transparent and resistant films, with lower water vapor permeabilities and lower water sorption capacities and xanthan gum addition improved the elongation ofa starch films.