Production and characterization of poly(3-Hydroxybutyrate-co-4-hydroxybutyrate) copolymer
| dc.contributor.author | Ahmad, Rahayu | |
| dc.date.accessioned | 2018-08-15T02:28:44Z | |
| dc.date.available | 2018-08-15T02:28:44Z | |
| dc.date.issued | 2011-07 | |
| dc.description.abstract | A locally isolated Cupriavidus sp. USMAA2-4 possessing the ability to produce biodegradable polymer was used in this study to explore the production of biopolymer through one-stage cultivation process and fed-batch fermentation. Various palm oilbased carbon sources, fatty acids and its combination were used for producing high cell dry weight of Cupriavidus sp. USMAA2-4. Utilization of oleic acid solely yielding the highest cell dry weight with 8.4 g/L. Effects of carbon to nitrogen (C/N ratio) on the accumulation of P(3HB) before feeding of carbon precursor (γ-butyrolactone) exhibited significant increased of 4HB compositions from 9 to 55 mol% when C/N ratio decreased from 20-8. The monomer composition of 4HB also varied from 4 to 55 mol% when alkanediols with even carbon numbers such as 1,4-butanediol, 1,6-hexanediol, 1,8- octanediol, 1,10-decanediol and 1,12-dodecanediol were used. Feeding strategy of interval feeding time could increased the cell dry weight up to 30 and 31.1 g/L according to 12 and 6 h interval of feeding time respectively, but the 4HB compositions unable to be varied. Feeding of C/N 5 at growth phase and supplementing different concentrations of γ-butyrolactone in accumulation phase using DO-stat method had successfully produced various 4HB compositions ranging from 35 to 68 mol% with the cell dry weight increased up to 14.9 g/L. The physical and mechanical properties of P(3HB-co- 4HB) copolymers were characterized by NMR spectroscopy, gel-permeation chromatography, tensile test and differential scanning calorimetry. Increase in the 4HB compositions lowered the molecular weight (Mn) of these copolymers which ranging xx from 31 x 103 to 441 x 103 Dalton and the polidispersities (Mw/Mn) were between 1.2 to 2.5. The randomness analysis using NMR spectroscopy confirms that the polymers produced using DO-stat method were blend copolymer. Tensile strength increase from 21 to 33 MPa with the elogation to break up to 14% as the 4HB composition increase. However, no significant differences were observed in the melting temperature (Tm) (170- 166C) with glass transition temperature (Tg) ranging from 5 to -45C. | en_US |
| dc.identifier.uri | http://hdl.handle.net/123456789/6312 | |
| dc.language.iso | en | en_US |
| dc.subject | Copolymers | en_US |
| dc.title | Production and characterization of poly(3-Hydroxybutyrate-co-4-hydroxybutyrate) copolymer | en_US |
| dc.type | Thesis | en_US |