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Weichmacherverlust bei PVC-Objekten von Joseph Beuys – Versuche zu kurativen und konservatorischen Massnahmen
ANHANG III: ZUSAMMENSTELLUNG VON ABSTRACTS
Zahran, A. H.; Nofal, E.; Elsabee, M. Z.; El-Azmirly, M. A. (1979): Irradiation of poly(vinyl chloride) with H2
plasma. In: Journal of Applied Polymer Science, Volume 24, Issue 7, Date: 1 October 1979, S. 1723-1737
A system has been designed to serve as a plasma source and has the advantage of producing plasma of known
energy and controlled intensity. Poly(vinyl chloride) films were irradiated with hydrogen plasma for different intervals of
time. The effect of irradiation time and storing on the extent of crosslinking was investigated. The viscosity of the
soluble part decreased at the initial stage of irradiation, then increased. The crosslinking extent was observed by
measuring the swelling ratio of the irradiated samples. Spectral analysis indicated the formation of carbonyl groups
and polyene structure in the irradiated PVC. The mechanisms of dehydrochlorination and crosslinking are discussed.
Balazs, D. J.; Triandafillu, K.; Chevolot, Y.; Aronsson, B.-O.; Harms, H.; Descouts, P.; Mathieu, H. J. (1979):
Surface modification of PVC endotracheal tubes by oxygen glow discharge to reduce bacterial
adhesion. In: Surface and Interface Analysis, 1979, Volume 35, Issue 3 , S. 301 - 309
A d.c. oxygen glow discharge was used to modify medical-grade PVC to study how surface chemistry and
hydrophilicity influence Pseudomonas aeruginosa adhesion. The effects of plasma exposure time on the resulting
surface, including chemical composition, wettability and roughness, were assessed using x-ray photoelectron
spectroscopy, contact angle measurements and atomic force microscopy analysis. A significant alteration in the
hydrophilicity of the native PVC surface was observed after oxygen glow discharge treatment. The water contact
angle decreased from 80° to 8-20°, with a weak dependence of the exposure time used. The change in surface
wettability resulted from the incorporation of oxygenated functional groups, including esters, ketones and acids, as
indicated by XPS analysis. The amount of oxygen incorporation was shown to be essentially independent of plasma
exposure time. However, prolonged plasma exposure resulted in increased surface roughness. Bacterial adhesion
efficiency was evaluated for PVC modified by 120 s of plasma exposure, because this exposure time was determined
to yield the maximum decrease in contact angle. Oxygen plasma treatment of native PVC was found to yield a 70%
reduction in bacterial adhesion for the four strains of Pseudomonas aeruginosa tested.