Effect of pressure on the intensity of absorption bands in the IR spectra of compacted polyethylene powde

The investigation of the IR spectra of compacted reactor powders of ultra-high-molecular-weight polyethylene showed that the intensities of the absorption bands depend on the compaction pressure; namely, they decrease with increasing pressure. It is found that the ultimate pressure above which the a...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Optics and spectroscopy 2009-02, Vol.106 (2), p.227-228
1. Verfasser: Aulov, V. A.
Format: Artikel
Sprache:eng
Schlagworte:
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:The investigation of the IR spectra of compacted reactor powders of ultra-high-molecular-weight polyethylene showed that the intensities of the absorption bands depend on the compaction pressure; namely, they decrease with increasing pressure. It is found that the ultimate pressure above which the absorption band intensity ceases to decrease depends on the spectral position of the band; the shorter the wavelength, the higher the ultimate pressure. This pressure is 5–10 MPa for bands in the long-wavelength spectral region (the band at 720 cm −1 ) and 100 MPa for the short-wavelength region (the band at 5875 cm −1 ). It is assumed that this phenomenon is related to a change in the size of pores d with pressing. Beams with wavelengths λ < d will undergo multiple diffuse reflections and reach a photodetector that is weaker than beams with λ > d . With increasing pressure, the size of pores decreases and the boundary between the two regions of the spectra shifts to short wavelengths.
ISSN:0030-400X
1562-6911
DOI:10.1134/S0030400X0902012X