Composition heterogeneity of tetrafluoroethylene-hexafluoropropylene random copolymers characterized by successive self-nucleation and annealing

Liu, L.; Tong, Zaizai; Xu, Jun‐Ting; Fan, Zhiqiang; Yu, Kao-Ming

doi:10.1007/s10973-013-3019-1

Cited by 8 publications

(3 citation statements)

References 42 publications

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“…Among these techniques, successive self‐nucleation and annealing (SSA) is the most sensitive, since it can provide faster and more efficient fractionation than other techniques. The SSA thermal protocol was designed and implemented for the first time by Müller et al in 1997 and its use has become widely spread in the past decades …”

Section: Introductionmentioning

confidence: 99%

Application of SSA thermal fractionation and X-ray diffraction to elucidate comonomer inclusion or exclusion from the crystalline phases in poly(butylene succinate-ran-butylene azelate) random copolymers

Arandia

Múgica

Zubitur

et al. 2016

J. Polym. Sci. Part B: Polym. Phys.

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Poly(butylene succinate‐ran‐butylene azelate) random copolyesters were thermally fractionated by successive self‐nucleation and annealing (SSA). The samples before and after SSA were analyzed by differential scanning calorimetry (DSC) and X‐ray diffraction (WAXS and SAXS). WAXS results indicate that a small degree of comonomer inclusion is present in the crystalline phases that are formed in the copolymers depending on composition: a PBS‐like unit cell or/and a PBAz‐like unit cell, thus confirming the isodimorphic behavior of the samples. SSA on the other hand demonstrated that the degree of comonomer exclusion during crystallization is far larger than comonomer inclusion, as judged by the increase in fractionation degree with compositions leading to the pseudo‐eutectic point. Furthermore, WAXS, SAXS, and SSA results show that the isodimorphic behavior is not highly dependent on kinetic factors, as the degree of comonomer inclusion or exclusion in the samples was not significantly altered by SSA thermal fractionation, a thermal treatment that promotes annealing and molecular segregation of defects to the amorphous regions of the material. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016, 54, 2346–2358

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Section: Introductionmentioning

confidence: 99%

Application of SSA thermal fractionation and X-ray diffraction to elucidate comonomer inclusion or exclusion from the crystalline phases in poly(butylene succinate-ran-butylene azelate) random copolymers

Arandia

Múgica

Zubitur

et al. 2016

J. Polym. Sci. Part B: Polym. Phys.

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“…51−54 The successive self-nucleation and annealing (SSA) technique can be used to evaluate the distribution of the lamellar crystal thickness, which may be further correlated to the distribution of crystallizable ethylene sequences. 55,56 Using this method, the ethylene sequences up to tens of nanometers can be measured. Figure 2a shows the DSC melting traces of four SEP samples after SSA thermal treatment.…”

Section: Resultsmentioning

confidence: 99%

“…13 C NMR can usually characterize the sequence distribution of copolymers in a short length, such as triads and tetrads in ethylene-propylene copolymers. By contrast, longer sequences are frequently related to crystallization behavior, such as the lamellar crystal thickness, thus can be characterized by DSC. − The successive self-nucleation and annealing (SSA) technique can be used to evaluate the distribution of the lamellar crystal thickness, which may be further correlated to the distribution of crystallizable ethylene sequences. , Using this method, the ethylene sequences up to tens of nanometers can be measured. Figure a shows the DSC melting traces of four SEP samples after SSA thermal treatment.…”

Section: Resultsmentioning

confidence: 99%

Chain Structure, Aggregation State Structure, and Tensile Behavior of Segmented Ethylene–Propylene Copolymers Produced by an Oscillating Unbridged Metallocene Catalyst

Tong

Huang

et al. 2015

J. Phys. Chem. B

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Segmented ethylene-propylene copolymers (SEPs) with different propylene contents were prepared by an unbridged metallocene bis(2,4,6-trimethylindenyl)zirconium dichloride [(2,4,6-Me3Ind)2ZrCl2] catalyst. Due to oscillation of the unbridged ligands in the catalyst, the SEPs are composed of segments with low propylene contents, alternated by the segments with high propylene contents. Such a chain structure was verified by (13)C NMR and successive self-nucleation and annealing (SSA). As the propylene/ethylene feed ratio during copolymerization increases, the comonomer contents in both segments are increased, leading to noncrystallizability of the high propylene segments and smaller crystallinity of the low propylene segments. Consequently, SEPs may be used as thermoplastic elastomers (TPEs). The aggregation state structures at nano- and micro-scales were characterized with small angle X-ray scattering, transmission electron microscopy and polarized optical microscopy, and compared with those of ethylene-octene multiblocky copolymers (OBCs) with similar crystallinity. It is found that SEPs form thinner lamellar crystals with a lower melting temperature due to shorter length and higher comonomer content of the low propylene segments. Moreover, the short length of the high propylene segments in SEPs results in an evidently thinner amorphous layer among the lamellar crystals, thus lots of amorphous phases are excluded out of the interlamellae. Accordingly, ill-developed spherulites or even bundle crystals are formed in SEPs, as compared with the well-developed spherulites in OBCs. SEPs exhibit the tensile property of typical TPEs with diffused yielding and large strain at break.

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Differential Scanning Calorimetry of Polymers

Müller

Michell

2016

Polymer Morphology

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Composition heterogeneity of tetrafluoroethylene-hexafluoropropylene random copolymers characterized by successive self-nucleation and annealing

Cited by 8 publications

References 42 publications

Application of SSA thermal fractionation and X-ray diffraction to elucidate comonomer inclusion or exclusion from the crystalline phases in poly(butylene succinate-ran-butylene azelate) random copolymers

Application of SSA thermal fractionation and X-ray diffraction to elucidate comonomer inclusion or exclusion from the crystalline phases in poly(butylene succinate-ran-butylene azelate) random copolymers

Chain Structure, Aggregation State Structure, and Tensile Behavior of Segmented Ethylene–Propylene Copolymers Produced by an Oscillating Unbridged Metallocene Catalyst

Differential Scanning Calorimetry of Polymers

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