Mechanical properties and highly ordered structure of ultra-high-molecular-weight poly[(R)-3-hydroxybutyrate] films: Effects of annealing and two-step drawing

Aoyagi, Yoshihiro; Doi, Yoshiharu; Iwata, Tadahisa

doi:10.1016/s0141-3910(02)00273-2

Cited by 98 publications

(104 citation statements)

References 29 publications

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“…This result is similar to the trend of increase in true crystallinity (see Fig. 3a) and also is in good agreement with the previous works [47][48][49][50]. The increase in the relative level of molecular orientation of crystalline phase could mainly result in the significant improvement of mechanical properties of the materials, corresponding to the strong enhancement in Young's modulus and tensile strength of the annealed iPP films as presented in Figs.…”

Section: Figsupporting

confidence: 92%

Influence of annealing on microstructure & molecular orientation, thermal behaviour, mechanical properties and their correlations of uniaxially drawn iPP thin film

Saengsuwan

2008

E-Polymers

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Abstract:The influence of annealing on the microstructure and molecular orientation, thermal behaviour and mechanical properties of uniaxially drawn iPP thin film was studied by wide-angle X-ray diffraction, differential scanning calorimetry and tensile testing, respectively. The correlations of mechanical and microstructural properties of annealed films were also examined. The transformation of smectic phase of iPP to the α-form was more pronounced with increasing annealing time and temperature. The true and apparent crystallinities and crystal thickness were strongly enhanced with annealing time and temperature. The relative molecular orientation tended to increase with annealing time. These results caused the significant improvement of modulus and tensile strength of the annealed films in both machine (MD) and transverse (TD) directions. The increases in MD-Young's modulus and MD-tensile strength were well correlated with the increase in true crystallinity obtained in equatorial scans. Some relationship between the increase in crystal thickness and the increase in Young's modulus in both MD and TD directions was also found.

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Section: Figsupporting

confidence: 92%

Influence of annealing on microstructure & molecular orientation, thermal behaviour, mechanical properties and their correlations of uniaxially drawn iPP thin film

Saengsuwan

2008

E-Polymers

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“…Because new polymer processing techniques for the preparation of strong fibers and films are being developed, [13,14] the P(3HB) homopolymer has recently received great attention as a potential candidate for commercial exploitation. However, as for the hot-drawing process of P(3HB) materials, one of the major problems is the decrease in molecular weight of polymer due to rapid thermal degradation near its melting temperature.…”

Section: Effect Of Pha Synthase Activity On Pha Productionmentioning

confidence: 99%

“…However, as for the hot-drawing process of P(3HB) materials, one of the major problems is the decrease in molecular weight of polymer due to rapid thermal degradation near its melting temperature. [13] Reducing the melting temperature of the polymer would be most effective in preventing this and allow for lower processing temperatures in the hot-drawing process. As shown in this study, P(3HB-co-3HHx) copolymers with small 3HHx fractions have markedly lower melting temperatures compared with those of P(3HB) homopolymers.…”

Section: Effect Of Pha Synthase Activity On Pha Productionmentioning

confidence: 99%

Biosynthesis and Compositional Regulation of Poly[(3‐hydroxybutyrate)‐co‐(3‐hydroxyhexanoate)] in Recombinant Ralstonia eutropha Expressing Mutated Polyhydroxyalkanoate Synthase Genes

Tsuge

Saito

Kikkawa

et al. 2004

Macromolecular Bioscience

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A new strategy for bacterial polyhydroxyalkanoate (PHA) production by recombinant Ralstonia eutropha PHB(-)4 harboring mutated PHA synthase genes (phaC(Ac)) from Aeromona caviae was investigated. The strain harboring wild-type phaC(Ac) gene produced a PHA copolymer consisting of (R)-3-hydroxybutyrate and (R)-3-hydroxyhexanoate [P(3HB-co-3HHx)] with 3.5 mol-% of 3HHx fraction from soybean oil. When the mutants of phaC(Ac) gene were applied to this production system, 3HHx fraction in copolymers was varied in the range of 0-5.1 mol-%. Thus, the regulation of PHA copolymer compositions has been achieved by the use of mutated PHA synthase genes.

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“…Accordingly, P(3HB) is considered as a polymer that is difficult to use in industrial applications because of its stiffness and brittleness. Some research groups have attempted to improve the mechanical properties of P(3HB) films (De Koning and Lemstra 1994;Barham and Keller 1986;Kusaka et al 1998Kusaka et al , 1999Aoyagi et al 2003;Iwata et al 2003) and fibers (Gordeyev and Nekrasov 1999;Schmack et al 2000;Yamane et al 2001;Furuhashi et al 2004;Iwata et al 2004). In the case of fibers, three groups have succeeded in obtaining melt-spun fibers with tensile strength of 190-420 MPa from P(3HB) produced by wild-type bacteria.…”

Section: Introductionmentioning

confidence: 99%

Manufacturing of PHA as Fibers

Iwata

Tanaka

2009

Microbiology Monographs

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Poly[(R)-3-hydroxybutyrate] and its copolymers have not been recognized as practical because of its stiffness and brittleness. Recently, we succeeded in obtaining strong fibers by two kinds of new drawing techniques from microbial polyesters produced by both wild-type and recombinant bacteria. The improvement of the mechanical properties of fibers is due not only to the orientation of the molecular chains but is also due to the generation of a planar zigzag conformation. The highly ordered and inner structures of strong fibers with tensile strength of over 1.0 GPa were analyzed by microbeam X-ray diffraction and X-ray microtomography

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Mechanical properties and highly ordered structure of ultra-high-molecular-weight poly[(R)-3-hydroxybutyrate] films: Effects of annealing and two-step drawing

Cited by 98 publications

References 29 publications

Influence of annealing on microstructure & molecular orientation, thermal behaviour, mechanical properties and their correlations of uniaxially drawn iPP thin film

Influence of annealing on microstructure & molecular orientation, thermal behaviour, mechanical properties and their correlations of uniaxially drawn iPP thin film

Biosynthesis and Compositional Regulation of Poly[(3‐hydroxybutyrate)‐co‐(3‐hydroxyhexanoate)] in Recombinant Ralstonia eutropha Expressing Mutated Polyhydroxyalkanoate Synthase Genes

Manufacturing of PHA as Fibers

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