Morphological study on three kinds of two-dimensional spherulites of poly(butylene terephthalate) (PBT)

Yoshioka, Taiyo; Fujimura, Takashi; Manabe, Norio; Yokota, Yoshimitsu; Tsuji, Masaki

doi:10.1016/j.polymer.2007.07.035

Cited by 21 publications

(13 citation statements)

References 17 publications

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“…This morphologic feature has never before been reported for PBT. Yoshioka et al14 studied the morphology of PBT and reported two flat‐on lamellar crystals growing radically from the center of the spherulite, like twin crystals. The proportion of both types of lamellar crystals was not 50%, and one type dominated at any given time.…”

Section: Resultsmentioning

confidence: 99%

Crystallization and morphology of polymerized cyclic butylene terephthalate

Jiang

2010

J Polym Sci B Polym Phys

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The crystallization behavior and morphology of polymerized cyclic butylene terephthalate (pCBT) were investigated by thermal differential scanning calorimetry (DSC) and polarized light microscopy (PLM). The spherulite growth rate was analyzed based on the Hoffman and Lauritzen theory to better understand the crystallization behavior. We found four typical morphologic features of pCBT corresponding to the crystallization temperature spectrum: usual negative spherulite, unusual spherulite, mixed birefringence spherulite coexisting with boundary crystals, and highly disordered spherulitic crystallites. The Avrami crystallization kinetics confirmed the occurrence of combined heterogeneous nucleation accompanied by a change in the spherulitic shape of pCBT, which also agreed with the PLM results. The equilibrium melting temperature and glass transition temperature of pCBT were 257.8 C and 41.1 C, respectively. A regime II-III transition occurred at 200.9 C, which was 10 C lower than that reported for poly(butylene terephthalate) (PBT). Coinciding with and attributed to the regime transition, the boundary crystal disappeared at temperatures above 200 C and the morphology changed from the mixed type to highly disordered spherulitic crystallites.

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Section: Resultsmentioning

confidence: 99%

Crystallization and morphology of polymerized cyclic butylene terephthalate

Jiang

2010

J Polym Sci B Polym Phys

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“…Hence, the mechanical properties of TPEE could be tuned via adjusting the ratio of the hard segment and soft segment. Poly(butylene terephthalate) (PBT) [ 25 , 26 , 27 , 28 , 29 , 30 ], which possesses excellent mechanical properties, thermal stability, thermal processability, and prominent crystallization ability, is seen as one of the most considerable hard segment materials.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Nonisothermal Crystallization Kinetics of Poly(Butylene Terephthalate-co-Tetramethylene Ether Glycol) Copolyesters

2020

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Poly(butylene terephthalate-co-tetramethylene ether glycol) (PBT-co-PTMEG) copolymers with PTMEG ranging from 0 to 40 wt% were synthesized through melt polymerization. The structure and composition were supported by Fourier-transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance spectroscopy (1H NMR). All samples had excellent thermal stability at a Td−5% around 370 °C. Crystallization temperature (Tc) and enthalpy of crystallization (ΔHc) were detected by differential scanning calorimetry (DSC), revealing a decrement from 182.3 to 135.1 °C and 47.0 to 22.1 J g−1, respectively, with the increase in PTMEG concentration from 0 to 40 wt%. Moreover, nonisothermal crystallization was carried out to explore the crystallization behavior of copolymers; the crystallization rate of PBT reduced gradually when PTMEG content increased. Hence, a decrement in the spherulite growth rate was detected in polarizing light microscope (PLM) observation, observing that the PTMEG could enhance the hindrance in the molecular chain to lower the crystallinity of PBT-co-PTMEG copolyester. Moreover, thermal properties and the crystallization rate of PBT-co-PTMEG copolymers can be amended via the regulation of PTMEG contents.

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“…1b), which is one of the typical birefringent properties of a spherulite. [18][19][20][21][22][23]26 We did not observe any interference colors except for black and white in Fig. 1b, which indicates that the retardation caused by the film is small.…”

Section: Resultsmentioning

confidence: 73%

“…The orientation of anisotropic rods or nanotubes in a certain direction is responsible for the observed birefringence in formed films. Similarly, some polymer films [18][19][20][21][22][23] and liquid crystal droplets 24,25 also display birefringence because each molecule/polymer chain is anisotropic in shape and they tend to form an oriented structure.…”

Section: Introductionmentioning

confidence: 99%

Optical anisotropy in packed isotropic spherical particles: indication of nanometer scale anisotropy in packing structure

Yamaguchi

Inasawa

Yamaguchi

2013

Phys. Chem. Chem. Phys.

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We investigated the origin of birefringence in colloidal films of spherical silica particles. Although each particle is optically isotropic in shape, colloidal films formed by drop drying demonstrated birefringence. While periodic particle structures were observed in silica colloidal films, no regular pattern was found in blended films of silica and latex particles. However, since both films showed birefringence, regular film structure patterns were not required to exhibit birefringence. Instead, we propose that nanometer-scale film structure anisotropy causes birefringence. Due to capillary flow from the center to the edge of a cast suspension, particles are more tightly packed in the radial direction. Directional packing results in nanometer-scale anisotropy. The difference in the interparticle distance between radial and circumferential axes was estimated to be 10 nm at most. Nanometer-scale anisotropy in colloidal films and the subsequent optical properties are discussed.

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Morphological study on three kinds of two-dimensional spherulites of poly(butylene terephthalate) (PBT)

Cited by 21 publications

References 17 publications

Crystallization and morphology of polymerized cyclic butylene terephthalate

Crystallization and morphology of polymerized cyclic butylene terephthalate

Synthesis and Nonisothermal Crystallization Kinetics of Poly(Butylene Terephthalate-co-Tetramethylene Ether Glycol) Copolyesters

Optical anisotropy in packed isotropic spherical particles: indication of nanometer scale anisotropy in packing structure

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