| Side-chain effect of second monomer units on crystalline morphology, thermal properties, and enzymatic degradability for random copolyesters of (R)-3-hydroxybutyric acid with (R)-3-hydroxyalkanoic acids. | |
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MedLine Citation:
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PMID: 11866565 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Three types of random copolymers with 94 mol % (R)-3-hydroxybutyric acid (3HB) and 6 mol % (R)-3-hydroxyalkanoic acids with different side-chain lengths, (R)-3-hydroxypentanoic acid (3HV), (R)-3-hydroxyhexanoic acid (3HHx), and medium-chain-length (R)-3-hydroxyalkanoic acids (mcl-3HA, C8-C12), were prepared by biological synthetic techniques. The solid-state structure and thermal properties of melt-crystallized films for copolymers were characterized by means of wide-angle X-ray diffraction, small-angle X-ray scattering, differential scanning calorimetry, and optical microscopy. The randomly distributed second monomer units, except for 3HV in copolyesters, act as defects of the P(3HB) crystal and are excluded from the P(3HB) crystalline lamellae. The lamellar thickness of copolymers decreased with an increase in the side-chain length of second monomer units. In addition, the growth rate of spherulites decreased with an increase in the carbon numbers of second monomer units at an identical crystallization temperature. These results indicate that a steric bulkiness of the second monomer unit affects the crystallization of (R)-3HB segments in random copolyesters. An enzymatic degradation test of melt-crystallized copolymer films was carried out in the presence of PHB depolymerase from Alcaligenes faecalis T1. Erosion rate of copolyesters was dependent on both the crystallinity and the lamellar thickness of samples. As the result, the rate of enzymatic degradation for copolymer films increased with an increase in the carbon numbers of second monomer units. |
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Authors:
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Hideki Abe; Yoshiharu Doi |
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Publication Detail:
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Type: Journal Article |
Journal Detail:
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Title: Biomacromolecules Volume: 3 ISSN: 1525-7797 ISO Abbreviation: Biomacromolecules Publication Date: 2002 Jan-Feb |
Date Detail:
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Created Date: 2002-02-27 Completed Date: 2002-06-19 Revised Date: 2006-11-15 |
Medline Journal Info:
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Nlm Unique ID: 100892849 Medline TA: Biomacromolecules Country: United States |
Other Details:
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Languages: eng Pagination: 133-8 Citation Subset: IM |
Affiliation:
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Polymer Chemistry Laboratory, RIKEN Institute, Hirosawa, Wako-shi, Saitama 351-0198, Japan. habe@postman.riken.go.jp |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Carboxylic Ester Hydrolases
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metabolism Crystallization Crystallography, X-Ray Hydroxybutyrates / chemistry*, metabolism* Kinetics Polyesters / chemistry*, metabolism* Polymers / chemistry*, metabolism Temperature Thermodynamics Time Factors |
| Chemical | |
Reg. No./Substance:
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0/Hydroxybutyrates; 0/Polyesters; 0/Polymers; 26063-00-3/poly-beta-hydroxybutyrate; EC 3.1.1.-/Carboxylic Ester Hydrolases; EC 3.1.1.-/poly-beta-hydroxybutyrate depolymerase |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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