Electron and X-ray diffraction study on poly(4-hydroxybutyrate)

Su, Fengyu; Iwata, Tadahisa; Sudesh, Kumar; Doi, Yoshiharu

doi:10.1016/s0032-3861(01)00412-8

Cited by 23 publications

(38 citation statements)

References 22 publications

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“…Again, all materials showed the characteristic features of semicrystalline solids as the XRD patterns combined the specific diffractions of ordered structural motifs with a broad background amorphous halo. The shape of the XRD patterns and position of diffraction maxima were in expedient correspondence with published XRD features of the P(3HB) and the P(4HB) lattice [21,[24][25][26][27]. Individual diffraction maxima were assigned to the corresponding reflections of the two crystal lattices in Figure 2.…”

Section: Detailed Crystallinity Assay Provided By Xrd and Dscsupporting

confidence: 74%

Introducing the Newly Isolated Bacterium Aneurinibacillus sp. H1 as an Auspicious Thermophilic Producer of Various Polyhydroxyalkanoates (PHA) Copolymers–2. Material Study on the Produced Copolymers

et al. 2020

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Aneurinibacillus sp. H1 is a promising, moderately thermophilic, novel Gram-positive bacterium capable of the biosynthesis of polyhydroxyalkanoates (PHA) with tunable monomer composition. In particular, the strain is able to synthesize copolymers of 3-hydroxybutyrate (3HB), 4-hydroxybutyrate (4HB) and 3-hydroxyvalerate (3HV) with remarkably high 4HB and 3HV fractions. In this study we performed an in-depth material analysis of PHA polymers produced by Aneurinibacillus sp. H1 in order to describe how the monomer composition affects fundamental structural and physicochemical parameters of the materials in the form of solvent-casted films. Results of infrared spectroscopy, X-ray diffractometry and thermal analysis clearly show that controlling the monomer composition enables optimization of PHA crystallinity both qualitatively (the type of the crystalline lattice) and quantitatively (the overall degree of crystallinity). Furthermore, resistance of the films against thermal and/or enzymatic degradation can also be manipulated by the monomer composition. Results of this study hence confirm Aneurinibacillus sp. H1 as an auspicious candidate for thermophilic production of PHA polymers with material properties that can be tuned together with their chemical composition by the corresponding adjustment of the cultivation process.

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Section: Detailed Crystallinity Assay Provided By Xrd and Dscsupporting

confidence: 74%

Introducing the Newly Isolated Bacterium Aneurinibacillus sp. H1 as an Auspicious Thermophilic Producer of Various Polyhydroxyalkanoates (PHA) Copolymers–2. Material Study on the Produced Copolymers

et al. 2020

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“…There is a close similarity between the X-ray diffraction pattern of PUDL and those of PPL, 27 PVL, 32 and PCL. 33 They are associated with the lateral packing distances between the polymer chains. A unit cell with the same a and b dimensions as PPL 27 and PVL, 32 but with a longer c-axis value obtained from the small-angle reflection, was selected as the starting cell.…”

Section: Resultsmentioning

confidence: 99%

“…Perhaps it is worth mentioning at this stage that models have been proposed for the aliphatic polyester PCL 33 and P(4HB) 28 in which the ester group twists slightly out of the all-trans conformation, although in a separate analysis an all-trans conformation was favored. For PUDL, no particular improvement in goodness of fit was obtained by the introduction of perturbations into the all-trans backbone.…”

Section: Resultsmentioning

confidence: 99%

Crystal Structure and Morphology of Poly(11-undecalactone) Solution-Grown Single Crystals

et al. 2004

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Solution-grown lamellar single crystals of poly(11-undecalactone) (PUDL) have been prepared in 1-hexanol. The lozenge and hexagonal-shaped single crystals were grown simultaneously, and these crystals gave well-resolved electron diffraction diagrams from which the orthogonal reciprocal lattice with the parameters a* ) 1.346 nm -1 , b* ) 2.004 nm -1 , and γ* ) 90°could be determined. The growth faces of both crystals were considered as mainly {110}, and the average chain-folding direction was parallel to these growth planes, suggesting that the hexagonal crystal has pseudohexagonal symmetry but actual orthogonal packing of the PUDL molecules. The diffraction analysis combined with X-ray and electron diffraction diagrams indicated that PUDL crystallized in the orthorhombic system which had the lattice parameters of a ) 0.743 ( 0.001 nm, b ) 0.499 ( 0.001 nm, and c(chain axis) ) 1.519 ( 0.003 nm. There are two chains per unit cell, which existed in an antiparallel arrangement. The fiber repeat distance is appropriate for an all-trans backbone conformation for the straight stems. Molecular packing of this structure has been studied in detail, taking into account both diffraction data and energy calculations. The setting angles, with respect to a axis, were 59°for the corner and center chains according to intensity measurements and structure factor calculations. A final model was obtained to yield R ) 0.173 with X-ray diffraction data and R ) 0.152 with electron diffraction data. A brief comparison is also made with related polymer structures.

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“…Among the biodegradable polyesters of the type (O(CH 2 ) m CO) n , the structures of single crystals have been resolved for poly( β ‐propiolactone) (PPL, m = 2),18 poly(4‐hydroxybutyrate) (P(4HB), m = 3),19,20 poly( δ ‐valerolactone) (PVL, m = 4),21 poly( ε ‐caprolactone) (PCL, m = 5),22–28 poly(11‐undecalactone) (PUDL, m = 10),29 poly(12‐dodecalactone) (PDDL, m = 11),30 and poly(15‐pentadecalactone) (PPDL, m = 14) 31. However, the crystal structure of poly(16‐hexadecalactone) (PHDL, m = 15) has not been studied yet.…”

Section: Introductionmentioning

confidence: 99%

Crystal Structure and Morphology of Poly(16‐hexadecalactone) Chain‐folded Lamellar Crystals

Kim

Uyama

Doi

et al. 2005

Macromolecular Bioscience

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Solution-grown, chain-folded lamellar crystals of poly(16-hexadecalactone) (PHDL) were crystallized isothermally from 1-hexanol at 70 degrees C. The morphology of lozenge-shaped crystals was studied by TEM and AFM. The lamellae are ca. 10 nm thick and the chains run orthogonal to the lamellar surface with folding along (110) and (110) planes. The crystal structure of PHDL was determined by XRD and election diffraction of single crystals. The chains are in the 2(1) helix conformation close to all-trans and the structure consists of an orthorhombic unit cell with a P2(1)2(1)2(1) space group with the lattice constants a = 0.746 +/- 0.001 nm, b = 0.504 +/- 0.001 nm, and c (chain axis) = 4.116 +/- 0.003 nm. There are two chains per unit cell, which exist in an antiparallel arrangement. Molecular packing structure has been studied in detail, taking into account both diffraction data and energy calculations. The setting angles, with respect to a axis, were +/-40 degrees for the corner and center chains, respectively. By using the electron and XRD data, the best molecular packing model was refined to R-factors of 0.168 and 0.196, respectively. A brief comparison of chain-packing structure is also made with related polymer structures.

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Electron and X-ray diffraction study on poly(4-hydroxybutyrate)

Cited by 23 publications

References 22 publications

Introducing the Newly Isolated Bacterium Aneurinibacillus sp. H1 as an Auspicious Thermophilic Producer of Various Polyhydroxyalkanoates (PHA) Copolymers–2. Material Study on the Produced Copolymers

Introducing the Newly Isolated Bacterium Aneurinibacillus sp. H1 as an Auspicious Thermophilic Producer of Various Polyhydroxyalkanoates (PHA) Copolymers–2. Material Study on the Produced Copolymers

Crystal Structure and Morphology of Poly(11-undecalactone) Solution-Grown Single Crystals

Crystal Structure and Morphology of Poly(16‐hexadecalactone) Chain‐folded Lamellar Crystals

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