Cristin-resultat-ID: 1271965
Sist endret: 24. september 2015, 20:12
Resultat
Vitenskapelig artikkel
2009

Crystallinity in ethylene-1-hexene copolymers determined by 1H- and 13C NMR in a comparative study

Bidragsytere:
  • Einar L Hinrichsen og
  • Åge Gellein Larsen

Tidsskrift

Macromolecules
ISSN 0024-9297
e-ISSN 1520-5835
NVI-nivå 2

Om resultatet

Vitenskapelig artikkel
Publiseringsår: 2009
Volum: 42

Importkilder

SINTEF AS-ID: S13717

Beskrivelse Beskrivelse

Tittel

Crystallinity in ethylene-1-hexene copolymers determined by 1H- and 13C NMR in a comparative study

Sammendrag

The 13C DD-MAS spectra of six ethene/1-hexene (E/H) copolymers were fitted simultaneously to a sum of four pseudo Voigt functions in which two were assigned to the alltrans crystalline region. These two peaks possessed the same chemical shift but differed in both line width and line shape. Regarding the amorphous region, it was found to be represented by a sum of a Lorenzian function and a Gaussian function possessing different chemical shifts. The latter simply reflects the asymmetry of the spatial distribution of transgauche conformations. The crystallinity of the samples, as determined by DSC, was found to be in excellent agreement with the crystallinity determined from 13C DD-MAS spectra. Moreover, the crystalline part of the 1H-FID (acquired at 0.5 T and 4.7 T) was fitted by using a Pake function and Abragamian function, respectively. The latter was found to give a crystallinity in quantitative agreement with the 13C DD-MAS and DSC. In contrast, the replacement of the Abragamian function with a Pake function (to represent the crystalline part of the FID) resulted often in unstable and poor model fits with rather unreliable estimate of the crystallinity. The inherent problem related to the necessary blanking of the receiver during the initial part of the FID (dead-time) is discussed.

Bidragsytere

Einar L Hinrichsen

  • Tilknyttet:
    Forfatter
    ved Materialer og nanoteknologi ved SINTEF AS

Åge Gellein Larsen

  • Tilknyttet:
    Forfatter
    ved Materialer og nanoteknologi ved SINTEF AS
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