2003 Fiscal Year Final Research Report Summary
High-functionability of ultra-high-molecular-weight biodegradable polyesters produced by recombinant Escherichia coli
| Project/Area Number |
13555263
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
高分子構造・物性(含繊維)
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| Research Institution | RIKEN (The Institute of Physical and Chemical Research) |
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Principal Investigator |
IWATA Tadahisa RIKEN, Polymer Chemistry Laboratory, Senior Scientist, 高分子化学研究室, 副主任研究員 (30281661)
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| Co-Investigator(Kenkyū-buntansha) |
YAMANE Hideki Kyoto Institute of Technology, Advanced Fibro-Science, Associate Professor, 工芸科学研究科, 助教授 (30191365)
SAWAWATARI Chie Shizuoka University, Integrated Sciences and Technology, Associate Professor, 教育学部, 助教授 (70196319)
TAGUCHI Kazunori RIKEN, Polemer Chemistry Laboratory, Senior Scientist, 高分子化学研究室, 研究員 (80332261)
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| Project Period (FY) |
2001 – 2003
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| Keywords | Poly([R]-3-hydroxybutyrate) / Ultra-high-molecular-weight / Hot-drawing / Cold-drawing / Two-step drawing / High-ordered structure / Planar zigzag conformation / Mechanical properties |
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| Research Abstract |
Poly([R]-3-hydroxybutyrate) (P(3HB)) is accumulated by a wide variety of microorganisms as intracellular carbon and energy material, and is extensively stud led as a biodegradable and biocompatible thermoplastic. However, the mechanical properties of P(3HB) homopolymer films markedly deteriorate by secondary crystallization. Recently, we succeeded in obtaining strong P(3HB) films and fibers by cold-drawing and two-step drawing procedures. The tensile strength of P(3HB) fiber is over 1.3 GPa. The improvement of mechanical properties is due not only to the orientation of molecular chains but also to the generation of a zigzag conformation and network structure formed by fibril and lamellar crystals. The mechanical properties remained unchanged for 6 months. These strong films and fibers were completely degraded in natural river freshwater within 4 weeks. The rate of erosion of P(3HB) films was controlled by the crystallinity of materials. P(3HB) single crystals were prepared from a dilute solution by isothermal crystallization. Enzymatic degradation of single crystals progressed from the edge of the crystals, or along their long axis while making small fragments.
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