Primary Nucleation Rate and Radial Growth Rate of Poly(ethylene oxide) Spherulite in Viscous Solutions

Sasaki, Takashi; Yamamoto, Yasuhisa; Takahashi, Toshisada

doi:10.1295/polymj.32.263

Cited by 10 publications

(16 citation statements)

References 21 publications

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“…We have already shown in a previ- ous study that the crystallization rate decreases with increase in the pre-annealing time for a PEO/TP system. 14,15 The primary nucleation rate I and the final asymptotic value of the number density of crystallites n f showed remarkable decreases with increase in preannealing time. These findings suggested heterogeneous nucleation due to incomplete dissolution on a microscopic order.…”

Section: Methodsmentioning

confidence: 99%

“…The procedure used for measurements was described in detail in our previous paper. 15 The equilibrium dissolution temperature T d…”

Section: Methodsmentioning

confidence: 99%

“…15 The obtained values are listed in Table I. The morphology of the obtained crystallites was observed using a polarizing optical microscope (Olympus BHSP-751).…”

Section: Methodsmentioning

confidence: 99%

“…This may be partially due to the micro-residuals of incomplete dissolution that remain in the solution in spite of the sufficient pre-annealing to achieve constant I with respect to pre-annealing time. 15 Very small impurities (smaller than 0.2 µm) may also act as seeds of nucleation. The obtained n(t) curves were fitted to the following empirical equation: 15…”

Section: Primary Nucleationmentioning

confidence: 99%

“…14,15 This is related to the so-called † To whom correspondence should be addressed. melt memory effect reported for melt crystallization.…”

Section: Introductionmentioning

confidence: 99%

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Crystallization of Poly(ethylene oxide) from Solutions of Different Solvents

Sasaki

Miyazaki

Sugiura

et al. 2002

Polym J

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ABSTRACT:The kinetics and crystalline morphology for isothermal crystallization of poly(ethylene oxide) (PEO) from solutions in three different solvents, N, N-dimethylacetamide (DMAc), toluene, and tripropionin (TP), were investigated. The energy barrier A of primary nucleation was highest for PEO/TP, and that of radial growth C was highest for PEO/toluene. Crystallites grew from both the DMAc and toluene solutions as aggregates of small layers of lamellae with branching and splitting. In addition, the crystallites from PEO/DMAc were found to have polygonal-like contours outside the lamella aggregates. This finding suggests that liquid-liquid phase separation occurred before or during the crystallization for PEO/DMAc. Relatively large spherulites were obtained from PEO/TP solutions due to the relatively low primary nucleation rate. The number density of the crystallites from PEO/TP was much lower than those from PEO/DMAc and PEO/toluene. KEY WORDS Poly(ethylene oxide) / Crystallization from Solutions / Primary Nucleation / Radial Growth / Solvent Effect / Morphology / Since polymer crystallization is essentially a kinetically-controlled process, the morphology of polymer crystals grown from solutions is very different from that in the case of bulk or melt crystallization due to the effects of polymer-solvent interaction, solution viscosity, concentration, molecular weight, and various other factors. The effect of solution concentration on the rate of crystallization can be treated by introducing an excess entropy term into the kinetic nucleation theory. 1-3 Nakajima et al. investigated the solvent effect on single crystal formation of polyethylene from various solutions, and they revealed that the thermodynamic interaction with solvent plays a dominant role. 4, 5 However, studies on the solvent effect have been done exclusively for single crystals from very dilute solutions, and the general characteristics of the solvent effect on solution crystallization have not yet been fully elucidated even from the phenomenological point of view. In some cases, strong interaction between a polymer and a solvent results in the formation of a polymersolvent compound 6, 7 or in physical gelation, [8][9][10][11] while in other cases, a liquid-liquid phase separation process may play a role in the crystallization. 10, 12, 13 However, the effects of liquid-liquid phase separation on kinetics and crystalline morphology have not been extensively studied.In our recent research on crystallization of poly(ethylene oxide) (PEO) from non-dilute solutions of a very viscous solvent, tripropionin (TP), we have found that the heterogeneity arising from incomplete dissolution in the initial solution plays an important role in the primary nucleation. 14,15 This is related to the so-called † To whom correspondence should be addressed. melt memory effect reported for melt crystallization. 17 The significance of this phenomenon should be renewedly assessed in the light of recent issue of the crystallization mechanism at very early stages. 16,18 ...

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Section: Methodsmentioning

confidence: 99%

“…The procedure used for measurements was described in detail in our previous paper. 15 The equilibrium dissolution temperature T d…”

Section: Methodsmentioning

confidence: 99%

“…15 The obtained values are listed in Table I. The morphology of the obtained crystallites was observed using a polarizing optical microscope (Olympus BHSP-751).…”

Section: Methodsmentioning

confidence: 99%

Section: Primary Nucleationmentioning

confidence: 99%

“…14,15 This is related to the so-called † To whom correspondence should be addressed. melt memory effect reported for melt crystallization.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Crystallization of Poly(ethylene oxide) from Solutions of Different Solvents

Sasaki

Miyazaki

Sugiura

et al. 2002

Polym J

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Melt and solution processability of poly(butylene succinate‐dilinoleic succinate) copolymers modified with poly(ethylene glycol) using3Dprinting and electrospinning

Zarei

Żwir

Wiśniewska

et al. 2023

Polymers for Advanced Techs

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Fabrication of complex structures usually requires a combination of different advanced manufacturing techniques at different length scales. In this work, we discuss the structure‐properties relationship of recently developed biodegradable poly(butylene succinate‐dilinoleic succinate) (PBS‐DLS) copolymers modified with hydrophilic poly(ethylene glycol) (PEG) towards their processibility via 3D printing and electrospinning. Notably, filaments suitable for 3D printing with 1.75 mm diameter were fabricated directly from the reactor after the synthesis of copolymers through extruding polymer melt into a water bath thus overcoming the postprocessing. Two series of copolymers containing 60 wt% and 70 wt% of hard PBS content were synthesized using magnesium‐titanium butoxide as heterometallic catalyst. Differential scanning calorimetry indicated biphasic morphology with low‐glass transition temperature and high‐melting point, which were dependent from the PBS hard segments content. Crystallized copolymers exhibited distinct spherulitic morphology, but presence of crystallites has no adverse effect on warping or delamination of subsequent layers during 3D printing. Furthermore, these copolymers demonstrated also easy processability through electrospinning, yielding uniform nanofibers with diameters ranging from 400 to 600 nm. The addition of 5 wt% PEG to copolymers with higher hard segments content (70 wt%) increased the elasticity up to 830% and improved hydrophilicity of the copolymers. Overall, these findings together with the excellent cell viability of new materials highlight their potential for different applications, including the biomedical sector.

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Multiple melting behavior of syndiotactic 1,2‐polybutadiene

Sasaki

Sunago

Hoshikawa

2003

Polymer Engineering & Sci

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A differential scanning calorimetry study on a typical thermoplastic elastomer, syndiotactic 1,2‐polybutadiene, crystallized from the melt is presented. Endotherms observed upon heating for samples isothermally crystallized from the melt exhibited a double melting profile. The peak temperature of the endotherm that appeared at a lower temperature (low endotherm) showed stronger dependence on the heating rate than that appearing at a higher temperature (high endotherm). The results of partial melting experiments demonstrated that the high endotherm is not affected at all by melting of only the crystals responsible for the low endotherm, indicating that the double melting behavior is due to the existence of two crystalline species with different stabilities. Structures and melting mechanisms of these two different crystalline species are discussed on the basis of the observed difference in superheating behaviors upon melting. The results on overall rate of isothermal crystallization are also presented.

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Primary Nucleation Rate and Radial Growth Rate of Poly(ethylene oxide) Spherulite in Viscous Solutions

Cited by 10 publications

References 21 publications

Crystallization of Poly(ethylene oxide) from Solutions of Different Solvents

Crystallization of Poly(ethylene oxide) from Solutions of Different Solvents

Melt and solution processability of poly(butylene succinate‐dilinoleic succinate) copolymers modified with poly(ethylene glycol) using3Dprinting and electrospinning

Multiple melting behavior of syndiotactic 1,2‐polybutadiene

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