Structural studies of polyesters: 5. Molecular and crystal structures of optically active and racemic poly (β-hydroxybutyrate)

Yokouchi, Mitsuru; Chatani, Yôzô; Tadokoro, Hiroyuki; Teranishi, Kiyoshi; Tani, Hisaya

doi:10.1016/0032-3861(73)90087-6

Cited by 453 publications

(371 citation statements)

References 11 publications

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“…To improve the mechanical and thermal properties of PHB, investigations of the crystalline structure, physical properties, and crystallization and melting behavior of PHB are essentially important. [49][50][51] Figure 4 illustrates the crystal and lamella structure of PHB. Recently, Sato et al [52][53][54] investigated the crystallization and melting behavior of PHB by using wide-angle X-ray diffraction (WAXD), IR spectroscopy, and differential scanning calorimetry (DSC).…”

Section: ·1 Applications To Polymer Science and Engineeringmentioning

confidence: 99%

Near-Infrared Spectroscopy—Its Versatility in Analytical Chemistry

2012

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Section: ·1 Applications To Polymer Science and Engineeringmentioning

confidence: 99%

Near-Infrared Spectroscopy—Its Versatility in Analytical Chemistry

2012

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“…The lattice indices of P(3HB) used for calculation of crystalline density d c were a 5:76 A; b 13:20 A; and c (®ber period) 5.96 A Ê [17], and those of P(4HB) used were a 7:75 A; b 4:79 A; and c (®ber period) 11.94 A Ê [18]. Here, the crystalline density d c of the copolymer was calculated additively.…”

Section: Characterization Of the Fractionated P(3hb-co-4hb) Samplesmentioning

confidence: 99%

Poly(3-hydroxybutyrate-co-4-hydroxybutyrate) produced by Comamonas acidovorans

Mitomo

Hsieh

Nishiwaki

et al. 2001

Polymer

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Poly(3-hydoxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] was biosynthesized by Comamonas acidovorans with mixed carbon sources of n-butyric acid and 1,4-butanediol. P(3HB) and P(3HB-co-94 mol% 4HB) were obtained by fermentation with sole carbon source of n-butyric acid and 1,4-butanediol, respectively. The content of 4HB component in P(3HB-co-4HB) increased as the composition of 1,4-butanediol in mixed carbon sources increased. These biosynthesized copolymers are not homogeneous, but mixtures of copolymers having different 4HB contents. Fractionation was carried out to obtain fractionated copolymers having a narrower distribution of composition. The change in structural and physical properties of the fractionated copolymers were investigated against the 4HB contents. Crystallinities of P(3HB-co-4HB)s were estimated using density values and the heat of fusion of P(3HB) measured was 125 J g 21 and that of P(4HB) was 76 J g 21 . q

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“…The same situation of temperature variation reported in the literature, but with other values, happens with the melting temperature. Some authors [10] mention that this value is 173 • C, but other values can be found: 175 • C [6], [73] or 180 • C [23], [60]. There are studies that mention ranges of variation for this temperature: 175 • C to 180 • C [56], or 170 • C to 180 • C [53], or 160 • C to 180 • C [18], ranges which cover all the values mentioned previously.…”

Section: Balance (T • M) When a Process Is Reversible Both Temperatmentioning

confidence: 97%

“…This is composed by 4 monomeric units in a orthorhombic system, with the following dimensions: a = 5.76 angstrom, b = 12.30 angstrom and c = 5.96 angstrom [60]. The molecules have helical conformation in L (indicating swing to the left), where each complete revolution is made by two monomeric units.…”

Section: Crystalline Structurementioning

confidence: 99%

From Obtaining to Degradation of PHB:Material Properties. Part I

et al. 2017

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This paper presents a review of the chemical, physical and morphological characteristics, as well as the existing applications and mechanisms for the production of poly (3-hydroxybutyrate). This biopolymer, which is obtained from renewable sources, degrades when exposed in biologically active environments and is biocompatible, that is, it is not rejected by the human body in health applications. However, in spite of presenting similar properties with some conventional plastics, the PHB exhibits fragile behavior and thermal instability when processed. The literature proposes the use of blends, the development of copolymers or the insertion of additives in an attempt to improve the mechanical and thermal properties of PHB. Key words: Biopolymers; polyhydroxyalkanoates (PHA); Polyhydroxybutyrate (PHB). Universidad EAFIT 269|From Obtaining to Degradation of PHB: Material Properties. Part I De la obtención a la degradación de PHB: Propiedades del material. Parte I ResumenEste artículo presenta una revisión de las características químicas, físicas y morfológicas, así como las aplicaciones y mecanismos existentes para la producción de poli(3-hidroxibutirato). Este biopolímero, que se obtiene a partir de fuentes renovables, se degrada cuando se expone en ambientes biológicamente activos y es biocompatible, es decir, no es rechazado por el cuerpo humano en aplicaciones de salud. Sin embargo, a pesar de presentar propiedades similares con algunos plásticos convencionales, el PHB exhibe comportamiento frágil e inestabilidad térmica cuando se procesa. La literatura propone el uso de mezclas, el desarrollo de copolímeros o la inserción de aditivos en un intento por mejorar las propiedades mecánicas y térmicas del PHB.Palabras clave: Biopolímeros; degradación de PHB; polihidroxialcanoato (PHA); polihidroxibutirato (PHB).

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Structural studies of polyesters: 5. Molecular and crystal structures of optically active and racemic poly (β-hydroxybutyrate)

Cited by 453 publications

References 11 publications

Near-Infrared Spectroscopy—Its Versatility in Analytical Chemistry

Near-Infrared Spectroscopy—Its Versatility in Analytical Chemistry

Poly(3-hydroxybutyrate-co-4-hydroxybutyrate) produced by Comamonas acidovorans

From Obtaining to Degradation of PHB:Material Properties. Part I

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