Please use this identifier to cite or link to this item: https://hdl.handle.net/10321/1746
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dc.contributor.advisorSithole, B.-
dc.contributor.advisorDeenadayalu, Nirmala-
dc.contributor.authorTywabi, Zikhonaen_US
dc.date.accessioned2016-11-18T06:57:01Z
dc.date.available2016-11-18T06:57:01Z
dc.date.issued2015-
dc.identifier.other663037-
dc.identifier.urihttp://hdl.handle.net/10321/1746-
dc.descriptionSubmitted in fulfillment of the requirements for the degree of Doctor of Technology: Chemistry, Durban University of Technology, Durban, South Africa, 2015.en_US
dc.description.abstractThis thesis forms part of the Council for Scientific and Industrial Research, Forestry and Forest Products Research Centre (CSIR-FFP) biorefinery project which aims at developing and implementing novel industrial processes production of cellulose textile fibres. The focus of this study is to investigate the dissolution of South African Eucalyptus raw (unbleached) and final (bleached) dissolving pulp and saw dust wood in an ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate [Emim][OAc] and the co-solvents [dimethylsulfoxide (DMSO)] or [dimethylformamide (DMF)] mixtures, to obtain regenerated cellulose by the further addition of water and acetone. The IL/co-solvent mixtures were able to dissolve the raw and final pulp samples at 120 ˚C for 6 hours whereas the sawdust wood dissolved in 10 hours. The IL/DMF mixture gave higher cellulose recoveries of 41.88 % for the raw pulp, 49.89 % for the final pulp sample and 32.50 % for sawdust wood while the IL/DMSO mixture gave a recovery of 15.25 % for the raw pulp sample, 36.25 % for the final pulp sample and 17.83 % for the sawdust wood sample. The regenerated cellulose materials were characterized by Fourier Transformer Infrared Spectroscopy (FTIR), Nuclear Magnetic Resonance (NMR), Scanning Electron Microscopy (SEM), Thermo gravimetric Analysis (TGA) and Powder X-Ray Diffraction (pXRD), and compared with a standard microcrystalline of cellulose. It was observed that the FTIR and NMR spectra of the regenerated cellulose and MCC were similar which then indicates that no chemical reaction occurred during the dissolution and regeneration process of cellulose. SEM and X-ray diffraction (XRD) patterns of the results showed that after dissolution the cellulose I (native form), the crystalline structure was completely converted into cellulose II (amorphous) structure, and this was due to the removal of lignin and decrease in cellulose crystallinity. TGA results showed that the regenerated cellulose samples have higher char yields compared to the MCC which is due to the IL remaining in the regenerated cellulose. It was also observed that the addition of the co-solvents decreased the viscosity of the IL mixture, facilitating dissolution of the cellulose that led to additional swelling and reduction of the recalcitrant nature of the cellulose crystalline structure and intermolecular interactions. This led to increased accessibility and dissolution of the cellulose. The findings in this study have the potential to bring ILs closer to applications for biomass technology in particular for an economically viable dissolution method for biomass because ILs have a benefit of being easily separated from the anti-solvent, which provides a simple solution for IL recycle ability and re-use. The novel aspect of this study is: . This is the first study in the South African context to examine the influence of the lignin on the dissolution and regeneration of Eucalyptus sawdust wood and dissolving pulp.en_US
dc.format.extent226 pen_US
dc.language.isoenen_US
dc.subjectSawdust wooden_US
dc.subjectRegenerated celluloseen_US
dc.subjectDissolving pulpen_US
dc.subjectCrystallinityen_US
dc.subjectDissolutionen_US
dc.subjectIonic Liquidsen_US
dc.subjectCo-solventsen_US
dc.subject.lcshIonic solutionsen_US
dc.subject.lcshDissolution (Chemistry)en_US
dc.subject.lcshWood-pulp--Dissolutionen_US
dc.subject.lcshCellulose--Dissolutionen_US
dc.subject.lcshWood--Chemistryen_US
dc.titleProcessing of dissolving pulp in ionic liquidsen_US
dc.typeThesisen_US
dc.description.levelDen_US
dc.identifier.doihttps://doi.org/10.51415/10321/1746-
local.sdgSDG14-
item.fulltextWith Fulltext-
item.openairecristypehttp://purl.org/coar/resource_type/c_18cf-
item.languageiso639-1en-
item.openairetypeThesis-
item.grantfulltextopen-
item.cerifentitytypePublications-
Appears in Collections:Theses and dissertations (Applied Sciences)
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