Properties of extruded xanthan-starch-clay nanocomposite films

Abstract

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

Using glycerol produced from biodiesel as a plasticiser in extruded biodegradable films

“…The presented results (Table 4) agreed with the results reported by other authors, which obtained an opacity value around 50%, for thermoplastic starch film [24,25] , and 34% for PBAT film [24] . Is important to point out that the results of this work for the blends starch/PBAT was intermediary when compared to the pure polymers, which were already expected.…”

Influence of thickness on properties of plasticized oat starch films

“…Studies have focused on the development of biodegradable packaging from the renewable sources and among the natural polymers, starch has become one of the most promising candidates due to its high availability, renewability and low cost (Tang et al 2012). Starches from different sources have been investigated regarding their film formation properties (Ferreira et al 2009;Melo et al 2011;Maran et al 2013). Starch shows thermoplastic behavior; however, if used pure, forms brittle films with lower flexibility requiring the addition of a plasticizer (Galdeano et al 2009a).…”

Influence of addition of silanized nanosilica and glycerol on hydrophobicity of starch using a factorial design

“…These are the most important sources of that carbohydrate [7] . Among the mentioned sources, the cassava starch can be highlighted for the production of thermoplastic starch (TPS), for presenting mechanical, chemical and physical properties that are interesting from the processing and application point of view [8] . Because of these characteristics, cassava starch has been studied by many Brazilian researchers, aiming at producing biodegradable plastics [9][10][11] .…”

“…Nevertheless, many limitations are noticed in relation to its hydrophilic characteristics and permeability to water vapor, which are responsible for the deterioration of mechanical properties and for dimensional stability [8][9][10][14][15][16][17][18] .…”