Author: Simon Kwan
Publisher:
Published: 2015
Total Pages:
ISBN-13:
DOWNLOAD EBOOK →
"Natural polymers like chitosan and cellulose have beneficial properties. Chitosan is being heavily researched as a potential for drug delivery, but it is not thermoresponsive, meaning that it does not change conformation when heated, a desirable property as one wants the drug to be released as it is being warmed by body temperature. Chitosan is therefore modified by grafting an acrylamide and subsequently, with a nitroxide initiator. This allows monomers to be grafted from the surface of the chitosan. Using oligo (ethylene glycol) methyl ether methacrylate (OEGMA8-9), 2-(2-methoxyethoxy) ethyl methacrylates (MEO2MA), and acrylonitrile, the monomers were successfully grafted from the surface of chitosan. The reaction is proven sucessful using FT-IR and NMR spectroscopy. Using UV-Vis spectroscopy, the thermoresponsive nature of chitosan was confirmed. Nanocrystalline cellulose is a very strong material with a large surface area to mass ratio. As such, it is currently being researched as nanocomposite reinforcer for plastics. However, cellulose is hydrophillic while most plastics are hydrophobic. Because its molecular structure is very similar to that of chitosan, a similar reaction can be used to modify the cellulose. The cellulose is modified by grafting styrene and 4-aminostyrene from the surface. This allows the surface to be hydrophobic and have amine groups. By using low-density-polyethylene modified with maleic anhydride, we believe this will give the cellulose the best chance to be well dispersed throughout the polyethylene via extrusion." --
