(640e) Effect Of Processing Parameters Of A Twin Screw Extruder On The Extent Of Exfoliation In Bio-Nanocomposites

The non-degradable and non-renewable nature of plastic packaging have given way to packaging materials based on biopolymers derived from renewable sources. However, biopolymers can not meet the requirements of a cost-effective film with mechanical and barrier properties matching those of plastics. Therefore, efforts have been geared towards developing biopolymer-based nanocomposites for food packaging films with enhanced mechanical and barrier properties. There are three possible arrangements of nanocomposites dispersed in a polymer matrix ? Non-intercalated, Intercalated, and exfoliated. Exfoliation is the ideal nanocomposite arrangement, but is harder to achieve during processing. Exfoliated bio-nanocomposites are made by blending nanocomposites with the biopolymer in a twin screw extruder. This paper investigates and quantifies the effect of processing parameters, namely screw speed, feed rate, barrel configuration, and barrel temperature on the extent of exfoliation. We synthesize exfoliated bio-nanocomposites by blending corn starch as the biopolymer and montmorillonite (MMT) as the nanoparticles and processing the blend in a twin screw extruder for a combination of processing parameters. We determine the extent of exfoliation by studying spatial distribution and dispersion of nanoparticles with the biopolymer using transmission electron microscopy (TEM). We also quantify the effect of processing parameters on the extent of exfoliation by developing correlations. Results from this study can be used to quantify the extent of exfoliation which is very critical in predicting the mechanical and barrier properties of these bio-nanocomposites.