Development of positron annihilation spectroscopy to test accelerated weathering of protective polymer coatings

Citation
R. Zhang et al., Development of positron annihilation spectroscopy to test accelerated weathering of protective polymer coatings, RADIAT PH C, 58(5-6), 2000, pp. 639-644
Citations number
8
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics
Journal title
RADIATION PHYSICS AND CHEMISTRY
ISSN journal
0969-806X → ACNP
Volume
58
Issue
5-6
Year of publication
2000
Pages
639 - 644
Database
ISI
SICI code
0969-806X(200006)58:5-6<639:DOPAST>2.0.ZU;2-7
Abstract
A variable mono-energetic positron beam with a computer-controlled system h as recently been constructed at the University of Missouri-Kansas City for weathering studies of polymeric coatings. The beam is designed to measure t he S-parameter from Doppler-broadening energy spectra and the sub-nanometer defect properties from positron annihilation lifetimes (PAL). Significant variations of S-parameter and ortho-positronium intensity in coatings, as o btained from the newly built beam and from the Electrotechnical Laboratory' s beam, respectively, are observed as a function of depth and exposure time due to the Xe-light irradiation. A high sensitivity of positron annihilati on signal response to the early stage of degradation is observed. Developme nt of positron annihilation spectroscopy to test accelerated weathering of polymeric coatings is discussed. (C) 2000 Elsevier Science Ltd. All rights reserved.