(107c) The Development of a Novel Method Using Cryogenic Grinding to Produce Chitin Nanofibers for Blending with Biodegradable Polymers

As plastics continue to buildup in our landfills, the demand for biodegradable polymers is ever increasing as an alternative to conventional polymers, which may take hundreds of years to break down in the natural environment. However, many of the current commercially available biodegradable polymers lack all of the desirable properties of conventional thermoplastic polymers. One such way to improve existing biodegradable polymers in functional applications is by reinforcing them with nanofibers in forms of nanocomposites. Of more recent interest in this area, chitin nanofibers have shown to increase Young’s modulus and toughness when incorporated into thermoplastic polymers. Chitin is a highly abundant natural biopolymer which is second only to cellulose. Chitin is the primary component of the exoskeletons of most arthropods, including crabs, prawns, and insects. It can also be found in fungi cell walls. Unlike cellulose though, the majority of chitin is just discarded as commercial waste. The exoskeletons are largely made up of a chitin fiber matrix along with minerals and proteins. Once the minerals and proteins are removed, the chitin fibers are strongly held together by hydrogen bonding which can make fibrillation quite difficult. Chitin is also not soluble in most common solvents. There are currently various methods in the literature used to produce chitin nanofibers including electrospinning, grinding with specially designed grinding stones, and high-pressure homogenization, but currently no methods that have been commercialized. Additional research is needed to develop new methods and improve existing methods of chitin fibrillation. In this study, a cryogenic grinder was used to grind commercially purchased chitin with additional modifications made to the grinding process to improve fibrillation. Results were analyzed by SEM, TGA, DSC, and XRD.