Motional heterogeneity of polystyrene-block-polybutadiene: a spin probe study

Čulin, Jelena; Andreis, Mladen; Veksli, Zorica; Gallot, Yves

doi:10.1016/j.polymer.2003.10.023

Cited by 8 publications

(6 citation statements)

References 31 publications

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“…The splitting of central component appears in ESR spectra of TEMPON and FPO nitroxides in PS and PVTMS. Similar component splitting in the intermediate temperature range between high and low temperatures were observed earlier in ESR spectra of spin‐labeled polymers, copolymers, macromolecules and also for nitroxides in liquid crystalline polymer 11, 52–56. Authors ascribed this feature to high anisotropy and complexity of molecular mobility.…”

Section: Discussionsupporting

confidence: 78%

Temperature dependence of ESR spectra of nitroxide spin probe in glassy polymers

Chernova

Vorobiev

2009

J Polym Sci B Polym Phys

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Temperature dependencies of ESR spectra of nitroxide spin probes in glassy polymers near and below glass transition temperature were examined in detail. Three temperature ranges, each characterized by specific changes in spectral shape, were defined. (i) In the low temperature range, ESR spectra of nitroxide radical in glassy polymer matrix weakly depend on temperature and remain qualitatively the same. (ii) In the intermediate temperature range, significant changes in the shape of spectra are observed. (iii) A new phenomenon was revealed near and below glass transition temperature: narrowing of linewidths occurs while the ratio of amplitudes of different components varies insignificantly. Analysis of molecular rotational mobility was carried out by means of commonly used empirical approaches. It was shown that widely used formulas and empirical approaches are not applicable for characterization of molecular mobility in glassy polymers. Mechanisms of rotational molecular movements in glassy polymers are discussed. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 563–575, 2009

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Section: Discussionsupporting

confidence: 78%

Temperature dependence of ESR spectra of nitroxide spin probe in glassy polymers

Chernova

Vorobiev

2009

J Polym Sci B Polym Phys

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“…The ESR spin‐probe method is known as a powerful technique for studying the motional heterogeneity of different polymer systems . In order to clarify the role of the chain mobility parameter on the diffusion of gases through deformed PE‐LLD films, ESR measurements were performed on undeformed and deformed samples.…”

Section: Resultsmentioning

confidence: 99%

Oxygen permeability, electron spin resonance, differential scanning calorimetry and positron annihilation lifetime spectroscopy studies of uniaxially deformed linear low‐density polyethylene film

Klepac¹,

Ščetar²,

Kurek³

et al. 2012

Polymer International

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Linear low‐density polyethylene (PE‐LLD) films were mechanically deformed at room temperature in both parallel and perpendicular directions to their initial orientation obtained during the manufacturing process. The degree of deformation ${\lambda}$, defined as ${\lambda} = l/l_{0}, l$ and l0 being the length of the deformed and relaxed samples, respectively, was varied from 1.0 to 2.0. Oxygen transport was investigated by a manometric method and the results were correlated with differential scanning calorimetry and positron annihilation lifetime spectroscopy measurements in order to investigate the contribution of various factors that influence the permeability of deformed PE‐LLD films. An electron spin resonance spin‐probe method was employed to determine the influence of uniaxial deformation on the chain segmental mobility in the amorphous phase. The results show that the deformation process reduces oxygen permeability and diffusion coefficients. It was found that the reduction is a combined effect of an increased crystallinity and reduced fractional free volume. The decrease of the chain segmental mobility with deformation plays an important role in the gas diffusion mechanism. © 2012 Society of Chemical Industry

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“…It was found that the range with two spectral components (the temperature interval between T a and T d ) and T 5mT value depend on the block length. The ESR spectra of PS-PB copolymers casted from different solvents have shown that the motion of probe III is sensitive to the domain morphology created by the solvent [56]. The segmented PU based on isophoronediisocyanate, polycaprolactone, and 1,4-butanediol with different amounts of functional groups introduced into the hard segments via second chain extender, 2,2 -bis-(hydroxymethyl) propionic acid, were investigated by nitroxyl radical IV used as a spin label.…”

Section: Copolymersmentioning

confidence: 99%