Eucalyptus oil

Peter N. Krantz <bkfndrs [at] ozemail__com__au> writes

>In conservation and archival use, does eucalyptus oil demonstrate
>any undesirable properties?

While there may be some constituents of raw eucalyptus oil that are
susceptible to oxidation /polymerisation, the main
ingredient,1,8-cineole, can be isolated as a pure compound.  This
substance is usually readily available from most leading chemical
suppliers (Fluka /Merck/Sigma etc.), and is far less likely to leave
a non-volatile residue than the raw oil.  1,8-cineole is a saturated
monoterpene hydrocarbon containing an cyclized ether functional
group, and would be expected to have some solvent action on
non-polar substances such as natural rubber, butylmethacrylate and
silicone pressure-sensitive adhesives.  I have done a few
experiments with it in the context of its effect on oil paints: it
has a low swelling effect on young-mature linseed oil paints.

There is quite a lot of information on eucalyptus oil and
1,8-cineole on the internet, partly because it has been proposed as
an environmentally-friendly alternative to petroleum-derived
solvents such as white spirits.  One of the leading authorities on
these substances is Dr. Allan Barton, a chemist at Murdoch
University in Perth, a highly respected specialist on solvents. (He
wrote the primary reference source on solubility parameters: Barton,
A. F. M. (1991). Handbook of Solubility Parameters and Other
Cohesion Parameters, (Second Edition). Boca Raton, Florida: CRC
Press. ISBN 0-8493-0176-9. ) For many years he has been working
towards the large-scale replanting of Eucalyptus oil mallees in
Australia to control dryland salinity, and the exploitation of the
by-product eucalyptus leaf oil as a substitute for environmentally
unacceptable industrial solvents. For those interested in more
information on eucalyptus oil and 1,8-cineole, the following
web sites are a highly recommended:

    <URL:http://www.mallee.com/eucoil.html>
    <URL:http://wwwchem.murdoch.edu.au/staff/barton>

Alan Phenix
Associate Professor,
Dept. of Conservation
Institute of Archaeology, Art History and Conservation
University of Oslo
Frederiks gt. 3
0164 Oslo
Norway


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                  Conservation DistList Instance 16:8
                 Distributed: Wednesday, July 24, 2002
                        Message Id: cdl-16-8-004
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