Mesophase structure of flexible‐chain polymers

Антипов, Е. М.; Kuptsov, S. A.; Куличихин, В. Г.; Tur, D. R.; Platé, N.A.

doi:10.1002/masy.19890260109

Cited by 10 publications

(3 citation statements)

References 11 publications

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“…In this phase, the orthorhombic PE crystalline structure is absent, while at the same time, some PE macromolecules contain trans-sequences with a length of at least 18 carbon atoms. We suppose that the aforementioned intermediate phase observed by Raman spectroscopy is the same as the liquid state phase revealed by the X-ray diffraction analysis in the melting region of PE [13]. It is also probable that this phase is associated to the so-called λ-transition in molten polymers [7].…”

Section: Ldpe and Ldpe/clay Nanocompositementioning

confidence: 74%

“…or conformationally different from both the crystalline and the disordered amorphous phases, and its role in crystallization/melting and mechanical relaxation processes have been the subject of discussion for some decades already [2,3,5,7,[9][10][11][12][13][14]. Three (the high temperature α-relaxation and the low-temperature β-and γ-relaxation) relaxation processes lying below the melting temperature T m , and another thermal transition (termed λ) just above T m , i.e.…”

Section: Introductionmentioning

confidence: 99%

“…This intermediate phase is also referred to as mesophase, interfacial or rigid amorphous phase [5]. A series of studies [13,14] showed that the melting/crystallization processes in flexible-chain polymers are actually more complicated than originally thought. X-ray diffraction measurements revealed that during heating, the crystalline phase of PE first transforms into a liquid crystal state and then into the true isotropic melt.…”

Section: Introductionmentioning

confidence: 99%

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Sensitive temperature-dependent phase resolution of polyethylene-clay nanocomposites

Sagitova¹,

Donfack²,

Prokhorov³

et al. 2022

Laser Phys.

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With the help of spectroscopic and differential scanning calorimetry (DSC) techniques, we have studied conformational and phase reorganizations as function of temperature in intercalated polymer-clay nanocomposites based on low-, middle-, and high-density polyethylene (PE) matrices. We show that Raman spectroscopy is sensitive to structural changes appearing during heating at much lower temperatures (about 47 °C) in comparison to DSC measurements. In fact, in the melting region where DSC traces show endotherms, Raman spectra reveal dramatic changes in the phase and conformational compositions of PE and PE-matrices within PE-clay nanocomposites. Noteworthy, the structural reorganization pathway, through which the semicrystalline nanocomposites transform into a melt state, depends primarily on the PE density and weakly on the filler (nanoclay). Moreover, the temperature-dependent crystallinity degree and the total amount of trans-conformers of the PE system are determined, and the evidence for the formation of intermediate crystal-like phase during heating is shown.

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Section: Ldpe and Ldpe/clay Nanocompositementioning

confidence: 74%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Sensitive temperature-dependent phase resolution of polyethylene-clay nanocomposites

Sagitova¹,

Donfack²,

Prokhorov³

et al. 2022

Laser Phys.

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Condis‐crystal structure of flexible‐chain polymers in polymer blends

Антипов

Borisenkova

Куличихин

et al. 1990

Makromolekulare Chemie. Macromolecular Symposia

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When heated above the melting point, a thermodynamic equilibrium mesophase of conformationally disordered crystal type (so‐called condis state) has been found in some flexible‐chain polymers (not containing mesogenic groups) dispersed in a matrix of another polymer. Typical organic and inorganic polymers such as polyethylene (PE) and poly[bis (2, 2, 2‐trifluoroethoxy) phosphazene] (PPh) were taken as main components of the polymer blends under investigation. The most interesting situation is realized if two mesophase polymers are used in the same binary blend.

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X‐ray diffusive scattering and the mesomorphic states in polymers

Kuz'min

Matukhina

Макарова

et al. 1991

Makromolekulare Chemie. Macromolecular Symposia

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The structural peculiarites of a number of polymers have been investigated by using the analysis of the X‐Ray amorphous scattering curves. These polymers were studied in three different (amorphous, semi‐crystalline and mesomorphic) phase states. By means of such type of analysis, it was shown that: 1) for the amorphous ethylene‐propylene random copolymer (PP‐PE) and for semicrystalline polyethylene (PE), the glass transition temperature can be determined with a high accuracy; 2) the mesomorphic state and the two structural transitions can be found in noncrystallized polydimethylsilmethylene (PDMSM); 3) besides the crystalline phase, two structural components having pure liquid and mesomorphic nature, may be determined in PE; 4) the mesomorphic state is revealed in poly‐4‐methyl‐pentene‐1 (P4MP1) in the temperature range both below and above the melting point; 5) the structural transition is realized within the mesomorphic state in poly‐deoamethyloyolohexasiloxanes (PDMCHSs); 6) a new meso‐phase 1‐ mesophase 2 transition is registered in poly‐diethylsiloxane (PDES).

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Mesophase structure of flexible‐chain polymers

Cited by 10 publications

References 11 publications

Sensitive temperature-dependent phase resolution of polyethylene-clay nanocomposites

Sensitive temperature-dependent phase resolution of polyethylene-clay nanocomposites

Condis‐crystal structure of flexible‐chain polymers in polymer blends

X‐ray diffusive scattering and the mesomorphic states in polymers

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