Graduate Thesis Or Dissertation
 

New approaches for analyzing white pitch deposits and grafting of synthetic polymers onto cellulose derivatives

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https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/hd76s447k

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  • White pitch deposits originated from the wood extractives, synthetic polymers, and additives used in the papermaking process, etc. may cause numerous problems to the papermaking process and also degrade the product quality. The timely analysis and characterization of white pitch deposit is important for tracing the origin of the deposits. Despite the severity of problem of white pitch deposits, there is little information on analysis of these contaminants. Gas chromatography (GC), size exclusion chromatography (SEC), proton nuclear magnetic resonance spectroscopy (¹H-NMR), and fourier transform infrared spectroscopy (FTIR) were used to separate the complex constituents and identify the functional groups of the white pitch deposits. GC analysis based on retention time allowed to determine paraffin wax, polyethylene wax, wood pitch residues, and certain additives such as rosin. Hot-melt adhesives and cis-1,4-polyisoprene were separated by SEC based on molecular weight and verified by FTIR and ¹H-NMR. By using instrumental analysis technique can analyze the complex white pitch deposits and trace the origin of those. Grafting of synthetic polymers onto cellulose and its derivatives is a useful way to improve their qualities and to expand the range of their uses. To date there are a few useful reaction schemes to prepare for the new classes of materials with the advantages of both material. Most of the proposed grafting reactions are carried out by free radical mechanisms. But these procedures have some inherent disadvantages. So in this study acylation reaction mechanism was adopted to achieve a high level of control compared to free radical reactions over the grafting reaction. Ethylene/maleic anhydride copolymer (EMA) and styrene/maleic anhydride copolymer (SMA) were grafted onto cellulose acetate (CA) and methyl cellulose (MC) in a simple and effective way under homogeneous reaction conditions. In addition to pyridine, N-methylimidazole (NMID) and 4-(N,N-dimethylamino) pyridine (DMAP) were used as catalysts to increase greatly the yield and rate of esterification.
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