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Titolo:
A DIRECT METHOD TO DETERMINE THE DEGREE OF CRYSTALLINITY AND LAMELLARTHICKNESS OF POLYMERS - APPLICATION TO POLYETHYLENE
Autore:
RYAN AJ; BRAS W; MANT GR; DERBYSHIRE GE;
Indirizzi:
UMIST,MANCHESTER MAT SCI CTR,GROSVENOR ST MANCHESTER M1 7HS ENGLAND SERC,DARESBURY LAB WARRINGTON WA4 4AD CHESHIRE ENGLAND
Titolo Testata:
Polymer
fascicolo: 21, volume: 35, anno: 1994,
pagine: 4537 - 4544
SICI:
0032-3861(1994)35:21<4537:ADMTDT>2.0.ZU;2-T
Fonte:
ISI
Lingua:
ENG
Soggetto:
X-RAY-SCATTERING; POLYURETHANE BLOCK COPOLYMERS; SYNCHROTRON RADIATION; SAXS; DIFFRACTION;
Keywords:
DEGREE OF CRYSTALLINITY; LAMELLAR THICKNESS; POLYETHYLENE;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
31
Recensione:
Indirizzi per estratti:
Citazione:
A.J. Ryan et al., "A DIRECT METHOD TO DETERMINE THE DEGREE OF CRYSTALLINITY AND LAMELLARTHICKNESS OF POLYMERS - APPLICATION TO POLYETHYLENE", Polymer, 35(21), 1994, pp. 4537-4544

Abstract

Time-resolved small-angle X-ray scattering (SAXS) and wide-angle X-ray scattering (WAXS) patterns have been simultaneously obtained during melting and crystallization of high-density polyethylene using a newlyconstructed camera at the SRS, Daresbury. The data have been analysedto yield the long spacing, the degree of crystallinity and the lamellar thickness in the context of the two-phase model. The long spacing was obtained from the peak in the Lorentz-corrected SAXS pattern. The degree of crystallinity was obtained from a combination of the SAXS invariant and the integrated WAXS intensity of the crystals. The invariant passes through a maximum at 50% crystallinity and the integrated WAXS intensity is a minimum for the melt. Thus two points in the linear relationship between the WAXS intensity and the degree of crystallinityare known, affording calibration. Calculation of the degree of crystallinity by solving the quadratic in the SAXS invariant gave good agreement with the WAXS result. The long spacing and the degree of crystallinity may be combined in the two-phase model to estimate the lamellar thickness, an important parameter in determining mechanical properties.

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Documento generato il 30/09/20 alle ore 09:36:12