Progress:
Quarterly Report: April 1-June 30, 2009
Bacterial cellulose (BC) is a promising biodegradable and sustainable material with broad potential for composite reinforcement. This cellulose is mainly excreted by the bacteria Acetobacter xylinum in the form of strong nano-fiber network. The objective of this research is to develop environment-friendly and biodegradable ‘green’ composites with good mechanical properties based on BC nano-fibers. Green composites are also based on sustainable materials rather than the conventional petroleum based polymers and fibers. Most efforts to date have used sucrose and other expensive sugars to grow bacterial cellulose (BC). In our research we used waste sugar products that are obtained from plant beans as the carbon source. This should reduce the cost of BC production substantially. Our preliminary results indicate that we can use waste sugars to grow BC. We will continue this effort to use various waste products to grow BC to understand their effects of sugar composition and various sugars on BC properties including their strength, dimensions, uniformity, etc. We will also characterize the bacterial activity and growth as a function of sugar compositions.
The second part of the research is to prepare green composites using BC and plant-based green resins. Our preliminary results have shown that we can add green resins to the sugar solutions during the BC culture to reduce the composite fabrication to a one-step process. Natural fibers such as sisal and ramie were also added to form novel hybrid ‘green’ composites with good properties. These have results in good mechanical properties of the BC based green composites. Both BC and the proteins have polar groups such as –NH2, -OH, and -COOH and which allow strong hydrogen bonding between the two resulting in excellent fiber/resin interfacial adhesion. We are currently exploring other means of improving the composite properties by incorporating micro-fibrillated cellulose (MFC), nano-fibrillated cellulose (NFC) and other nano-particles within the BC using similar one-step process.
