ABSTRACT KUMAR, PRABHAT. Development of Bio-nanocomposite Films with Enhanced Mechanical and Barrier Properties Using Extrusion Processing. (Under the direction of Dr.

Recently, a new class of materials represented by bio-nanocomposites (biopolymer matrix reinforced with nanoparticles) has proven to be a promising option in improving mechanical and barrier properties of biopolymers derived from renewable sources. Therefore, the current study was undertaken with the main objective of developing bio-nanocomposite films based on soy protein isolate (SPI) and montmorillonite (MMT) with enhanced mechanical and barrier properties by melt intercalation using extrusion processing. Effects of extrusion processing parameters (screw speed and barrel temperature distribution) and type (natural and modified) and content (0-15%) of MMT on the structure (degree of intercalation and exfoliation) and properties (mechanical, dynamic mechanical, thermal stability, and water vapor permeability) of SPI-MMT bio-nanocomposites were studied. The arrangement of MMT in the bio-nanocomposite matrix ranged from exfoliated to intercalated depending on the type (natural and modified) and content of MMT. The results showed that extrusion of SPI and MMTs resulted in bio-nanocomposites with exfoliated structures at lower MMT content (5%) for natural (Cloisite Na+) as well as modified MMTs (Cloisite 20A and Cloisite 30B). At higher MMT content (15%), structure of bio