Effect of self‐nucleation on the crystallization of segmented copolymer poly(ether ester)

Gu, Qun; Wu, Liheng; Wu, Dongfang; Shen, Deyan

doi:10.1002/app.1463

Cited by 6 publications

(10 citation statements)

References 18 publications

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“…Web samples of 3–5 mg were placed in open DSC pans, vacuum‐dried at 60°C for 3 h, and kept in desiccators until just before loading into the DSC 18. To observe the crystallization exotherm and determine the onset of crystallization, web samples were first heated to temperatures 40–50°C above their peak melting temperature at 20°C min −1 , maintained at this temperature for 3 min to ensure complete melting, and then were cooled to 25°C at 10°C min −1 36…”

Section: Methodsmentioning

confidence: 99%

Crystallization behavior of elastomeric block copolymers: Thermoplastic polyurethane and polyether‐block‐amide

Begenir¹,

Michielsen²,

Pourdeyhimi³

2008

J of Applied Polymer Sci

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ABSTRACT:The isothermal crystallization kinetics of melt-blown webs produced from a series of elastomeric block copolymers was studied through differential scanning calorimetry (DSC). Three hardness grades were selected for a polyester and a polyether Elastollan V V R thermoplastic polyurethane and Pebax V V R polyether-block-amide copolymers. The Avrami crystallization kinetics parameters, k and n, were derived from two different methods: (1) traditional Avrami model and (2) derivative of the Avrami model proposed by Kurajica et al. (Croat Chem Acta 2002, 75, 693). The kinetic parameters from both models were consistent and showed good correlation. For all polymer types and hardness grades, crystallization kinetics were interpreted with the derivative model (Kurijica et al.) since it could be directly fitted to untransformed DSC isothermal crystallization data, and thus reduces the errors involved in Avrami analysis. The values of the Avrami exponent, n ranged between 2.59 and 3.41, indicating similar nucleation and growth mechanisms. These n values and morphological observations indicate that crystallization occurs in these copolymers in three dimensions from pre-existing nuclei and the crystals grow under isothermal conditions. This suggests that, in these elastomeric copolymers, crystallization of the hard segments drives microphase separation into crystalline and amorphous regions rather than formation of hard and soft domains.

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Section: Methodsmentioning

confidence: 99%

Crystallization behavior of elastomeric block copolymers: Thermoplastic polyurethane and polyether‐block‐amide

Begenir¹,

Michielsen²,

Pourdeyhimi³

2008

J of Applied Polymer Sci

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“…Acceleration of the nucleation step can be accomplished by previous SN of the polymer. Under these conditions, the crystallization rate of self-nucleated material increases such that isothermal DSC can be performed [4,69,76,96,123,[139][140][141][142][143][144][145][146][147][148][149][150][151][152]. It is well known that overall crystallization kinetics obtained by isothermal DSC experiments contains both nucleation and growth components.…”

Section: Self-nucleation Before Isothermal Crystallizationmentioning

confidence: 98%

“…The value of K On the other hand, the same LH analysis was performed on spherulitic growth data for neat PPDX homopolymer. The value obtained for the secondary nucleation constant for PPDX spherulitic growth was K This technique of performing SN just before isothermal DSC measurements has been applied to segmented copolymers of poly(ether ester), based on poly(ethylene glycol) and poly(ethylene terephtalate) [139], PP [63,133,141,151], PCL [142], PPDX [142], poly(ε-caprolactone)-block-poly(propyleneadipate) [143], poly(ethylene naphthalate) [144], poly(propylene suberate) [145], poly(propylene Then, the sample is cooled at 10 C/min to obtain a "standard" crystalline state (point 2). The sample is then ideally self-nucleated by heating to point 3.…”

Section: Self-nucleation Before Isothermal Crystallizationmentioning

confidence: 99%

Self-Nucleation of Crystalline Phases Within Homopolymers, Polymer Blends, Copolymers, and Nanocomposites

Michell

Múgica

Zubitur

et al. 2015

Polymer Crystallization I

116

303

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Self-nucleation (SN) is a special nucleation process triggered by selfseeds or self-nuclei that are generated in a given polymeric material by specific thermal protocols or by inducing chain orientation in the molten or partially molten state. SN increases the nucleation density of polymers by several orders of magnitude, producing significant modifications to their morphology and overall crystallization kinetics. In fact, SN can be used as a tool for investigating the overall isothermal crystallization kinetics of slow-crystallizing materials by accelerating the primary nucleation stage in a previous SN step. Additionally, SN can facilitate the formation of one particular crystalline phase in polymorphic materials. The SN behavior of a given polymer is influenced by its molecular weight, molecular topology, and chemical structure, among other intrinsic and extrinsic characteristics. This review paper focuses on the applications of DSC-based SN techniques to study the nucleation, crystallization, and morphology of different types of polymers, blends, copolymers, and nanocomposites.

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“…Fillon et al 32 have reported that the self-nuclei can be generated and studied in a controlled fashion by use of a suitable self-nucleation protocol in the DSC analysis. This approach has been widely employed to study the self-nucleation [33][34][35][36][37] and fractionated crystallization [23][24][25] of polymers. They divided the self-nucleation temperature (T s ) in three domains.…”

Section: Introductionmentioning

confidence: 99%

Fractionated crystallization and self‐nucleation behavior of poly(ethylene oxide) in its miscible blends with poly(3‐hydroxybutyrate)

Pan

Zhu

et al. 2010

J of Applied Polymer Sci

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ABSTRACT:The fractionated crystallization and selfnucleation behavior of poly(ethylene oxide) (PEO) component in the miscible PEO/poly(3-hydroxybutyrate) (PHB) binary blends were investigated using differential scanning calorimetry (DSC) and small-angle X-ray diffraction (SAXS) under different crystallization conditions. The distribution of PEO component in the PEO/PHB blend greatly influences its fractionated crystallization behavior. The active heterogeneities, on which the semicrystalline components in the molten state can nucleate at a small supercooling, are favored to locate out of the interlamellar regions of PHB crystals during the crystallization of PHB component. The PEO component confined in the interlamellar regions of PHB crystals crystallizes at an extremely large supercooling, which is induced by the homogeneous nucleation or less active heterogeneities, while the PEO component expelled out of the interlamellar regions of PHB crystals can crystallize at a small supercooling due to the nucleation induced by active heterogeneities. In addition, the self-nucleation behavior of PEO component in the PEO/PHB blend is also affected by the active heterogeneities and the distribution of PEO phase in the blend. Different from the block copolymer systems, the PEO component confined into the interlamellar regions of PHB crystals can not be selfnucleated in the PEO/PHB blend without a nucleating agent (NA).

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Effect of self‐nucleation on the crystallization of segmented copolymer poly(ether ester)

Cited by 6 publications

References 18 publications

Crystallization behavior of elastomeric block copolymers: Thermoplastic polyurethane and polyether‐block‐amide

Crystallization behavior of elastomeric block copolymers: Thermoplastic polyurethane and polyether‐block‐amide

Self-Nucleation of Crystalline Phases Within Homopolymers, Polymer Blends, Copolymers, and Nanocomposites

Fractionated crystallization and self‐nucleation behavior of poly(ethylene oxide) in its miscible blends with poly(3‐hydroxybutyrate)

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