Project/Area Number |
11217205
|
Research Category |
Grant-in-Aid for Scientific Research on Priority Areas
|
Allocation Type | Single-year Grants |
Review Section |
Science and Engineering
|
Research Institution | Tokyo Institute of Technology |
Principal Investigator |
YOSHIE Naoko Tokyo Institute of Technology, Dep. Biomolecular Engineering, Assistant Professor, 大学院・生命理工学研究科, 助手 (20224678)
|
Project Period (FY) |
1999 – 2002
|
Project Status |
Completed (Fiscal Year 2002)
|
Budget Amount *help |
¥12,900,000 (Direct Cost: ¥12,900,000)
Fiscal Year 2002: ¥2,800,000 (Direct Cost: ¥2,800,000)
Fiscal Year 2001: ¥2,800,000 (Direct Cost: ¥2,800,000)
Fiscal Year 2000: ¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 1999: ¥4,100,000 (Direct Cost: ¥4,100,000)
|
Keywords | bacterial copolyesters / microstructure / structural transition / in situ observation of crystallization / cocrystallization / 微生物産生ポリエステル / 生分解性ポリマー / 顕微FTIR / ポリマーブレンド / 共結晶化 / 結晶相分離 / 結晶構造転移 / 化学組成分布 / 微細構造 / 結晶相組成 / 生分解ポリマー |
Research Abstract |
Poly [(R)-3-hydroxybutyrate] [PHB] and its copolymers, which are produced from renewable resources by bacterial fermentation, attract widespread interest as biodegradable thermoplastics. In this project, mutual relation between microstructure and properties of bacterial copolyesters were analyzed. Properties of Polymeric materials are correlated with structures of diverse levels from atomic to macroscopic scales, this project was directed toward deep analysis of a copolyester, poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHB-HV), rather than shallow one of various coplyesters. We have achieved the following results. 1. A speculer structural transition was found at ca. 10 mol% HV for PHB-HV with narrow chemical composition distribution. 2. For PHB-HV with bimodal chemical composition distribution, the phase structure changes from perfect cocrystallization of all the PHB-HV chains, via crystallization of the PHB-HV with high HV content, to phase segregation preceding crystallization with the increase of the difference in the peak positions in composition distribution and/or the decrease of the crystallization temperature. Coincidentally various properties of PHB-HV remarkably changes. 3. Through in situ observation of crystallization of PHB-HV with bimodal composition distribution by FTIR microscopy, the formation mechanism of the phases described above was demonstrated.
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