Summary: | 碩士 === 國立臺灣大學 === 食品科技研究所 === 106 === The current global consumption petroleum plastics is more than 200 million tonnes, and is still increasing. Petrochemical-based materials are not environmental-friendly. Recent years, many scholars and industries have focused on the development of composites with renewable, biodegradability, low cost, non-petroleum sources and low carbon dioxide emissions. The biodegradable polymer has potential to be the active packaging material. Chitin is the second abundant macromolecular polymer in the world, with the advantages of low cost and feasible. However, it can only dissolved in special solvent, which limits the applications. In this study, media-milling was used, instead of solvents: DMAc, LiCl and N-methyl-2-pyrrolidone, with water as a solvent for processing chitin, which is an environment-friendly processing method. To enhance the anti-bacterial effect, essential oil had been used in chitosan film for food packaging. In this study, thyme oil (0, 0.5, 0.75, 1, 1.25g) was added to chitin suspension (30, 60, 90 milled). The physical properties of chitin films containing thyme oil and their antibacterial properties were investigated. As the addition of thyme oil increases, the total absorbance and the thickness of the films increase. SEM showed the cross-section of the films had layered structures. The addition of thyme oil increased the gap between layers. The changes of tensile strength are 30 min-milled > 60 min-milled > 90 min-milled chitin films with same addition of thyme oil. The elongation at break of the film does not increase as the amount of the thyme oil increases. XRD showed that 2
|