Klucel G

Liz Branigan writes:

>We are considering using Klucel G in ethanol, as an adhesive for
>backing tracing papers,but have the idea that Klucel possibly
>discolours over time. Has anybody come across this problem?

>From some handout paper from Gerhard Banik about cellulose ethers:

    "Investigations of J. Hofenk de Graaff (1981): Klucel
    (hydroxy-propyl-cellulose) shows good ageing characteristics and
    have a positive effect on the ageing properties of paper.

    Study of Feller and Wilt (1990) gives indication that the long
    term stability of Klucel is lower than the expected from the
    findings of Hofenk De Graaff.

    The findings of Feller and Wilt shows that Klucel has excellent
    photochemical stability towards visible and near ultraviolet
    radiation.  Furthermore, the compound has little tendency to
    form peroxides during ageing.  However, Klucel was classified
    as thermally unstable as thermal ageing at 90 degree celsius
    leads to considerable discolouration and a strong loss in
    weight.

    This was interpreted that the material will have a potential for
    discolouration and significant decrease in degree of
    polymerization under moderate ageing conditions within a time
    period of 20 years. It was additionally stated that the higher
    molecular weight grades (Klucel M and H) seems to be less stable
    than the lower molecular weigh grades Klucel G and L.  Feller
    and Wilt therefore, consider the latter grades as products of
    intermediate thermal stability.  For a final statement more
    investigations seems to be necessary."

Klucel G is also widely used a consolidant for red rot leather and
deteriorated paper. I have only done a few restoring of tracing paper
and have used 1:1 methylcellulose with wheat paste and
japanese-paper.

Soren Ibsen
Book- and paperrestorer
Norwegian University of Science and Technology
University Library of Trondheim
Gunnerus Library
Erling Skakkes gate 47 c
N-7491  Trondheim.
Norway
+47 7359 2132
Fax: +47 7359 2100

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                  Conservation DistList Instance 13:32
                Distributed: Thursday, December 2, 1999
                       Message Id: cdl-13-32-006
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