Glucose, as the most plentiful sugar in nature, is a renewable resource and possesses excellent record in health safety. Levulinic acid is a platform chemical which plays an important role in biomass transformation and reactive intermediates. Both glucose and levulinic acid can be produced by biomass conversion with green processing techno logies. Due to the rising needs for bio-based, eco-friendly and non-toxic plasticizers, glucose levulinates as bio plasticizers were synthesized from glucose and levulinic acid, by utilizing microwave radiation or conventional condensation reaction (direct-heating method ). Acid number for the reaction liquor was measured by acid-base titration to follow the decrease of acid groups due to the reaction and the trend in the acid number within reaction time displayed the process of esterification and possible sensitivity of the reaction rate to reaction scale. It showed that microwave radiation had superior ability in enhancing reaction speed but it was also more sensitive to reaction scale and generated more diverse prod ucts than the direct-heating method. Besides, the process of reaction and formation of ester bonds was followed and confirmed by FT IR. The achieved levulinate products were extracted by 2-pro panol and ethyl acetate. The practices showed several serio us problems in 2-propanol extraction, including high dosage required for NaCl and solvent and difficulties in purification. The ethyl acetate proved to be a suitable solvent for this study and the extrac ted product s from the Con-24hrs and Micro-3/4/5/6/7hrs were characterized by 1H NMR, 13C N :tvlR. and LDI-MS. The results from spectrum suggested the presence of GL,. and G J .'l. type of levulinates. That means the glucose levulinates were successfully synthesized although the dehydration side reaction of glucose was inevitable leading to the generation of glucosidic bonds. In addition, BG (mixture of glucose and glycosidic levulinates) was evaluated by so lution casting of starch and PVC. In order to minimize the microbial contaminations in solution casting of starch, a modified method was raised and applied. The results showed that 40% BG had goo d miscibility with starch and the conclusion was further proved by DSC measurements, while the BG performed poor miscibility with PVC.
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:kth-218153 |
| Date | January 2017 |
| Creators | Xuan, Wenxiang |
| Publisher | KTH, Skolan för kemivetenskap (CHE) |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
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