This research investigates the extraction of cellulose from rice straw, which is an agricultural waste product to produce CNC and its utilization for the development of biodegradable and environment friendly nanocomposite films. CNC extracted from rice straw through cyclic alkaline and bleaching treatment method appeared as long, welldefined rodlike crystals with high aspect ratio of 41. Polyvinyl alcohol (PVOH), a popular biodegradable and biocompatible polymer was chosen as the polymer matrix. PVOH/CNC bionanocomposite films were made through employing solution casting method with different weight percentages to determine the optimum CNC weight percentage (wt%). It was found that 3 wt% CNC incorporation vastly improved the
tensile strength by 60.4%, maximum degradation temperature to 287 ºC, water vapor permeability rate and swelling and solubility resistance of PVOH/CNC. The optimum CNC amount was found to be at 3 wt%. In order to address the issue of hydrophilicity and diversify the use of the bionanocomposite, a more versatile bionanocomposite was developed with the introduction of ethanedioic acid (EA) as a crosslinker. Crosslinked nanocomposite displayed significant improvements where tensile strength increased by 104.8%, maximum degradation temperature to 364 ºC, water vapor permeability rate, solubility and swelling resistance. Finally, biodegradation study is an appealing investigation for the development of a more efficient and environmentally friendly plastic waste disposal. The current work also aimed to study the biodegradation behavior and its degrading bacterias of noncrosslinked and crosslinked PVOH/CNC bionanocomposites
through natural soil burial method. The degrading bacterias were isolated and identified to be Bacillus cereus strain CCM 2010 and Bacillus cereus strain ATCC 14579 from 16S rRNA gene sequencing. The changes in functional groups before and after biodegradation were confirmed through Fourier-transform infrared spectroscopy. Tensile test revealed that the tensile strength and elongation at break reduced as time of soil burial increases. Morphological study showed the extent of surface deterioration of bionanocomposites before and after soil burial, where the addition of EA displayed lessened deterioration. Total weight loss also decreased after crosslinking occurred. Melting temperature and crystallinity increased with addition of CNC but reduced after crosslinking. Melting temperature and crystallinity of all nanocomposites increased after biodegradation for all bionanocomposites. Biodegradation of the bionanocomposites were concluded to be in the following decreasing order: PVOH/CNC > PVOH/EA/CNC > PVOH > PVOH/EA.
