Polyvinyl acetate

Leslie Beck  posted a message concerning the reversibility and
flexibility of polyvinyl acetate (PVA) after treatment of paper
materials.

In a paper published elsewhere we (*) examined the Infrared Spectra
(IR) of cellulose paper sized with PVA and other polymers before and
after artificial ageing in normal and acidic atmosphere. It appeared
that in both cases the main infrared band (1738 cm-1) of PVA is
subjected to a strong variation, possibly because of the hydrolysis
of ester group, so that (artificial) ageing leaves something which
is different from starting adhesive. This result might explain the
difficulty in removal acetate-based adhesives in old treated sheets.

    (*) M.G. Plossi Zappala' and P. Calvini, "Identificazione di
    polimeri sintetici applicati su carta mediante spettrofotometria
    IR" (Infrared identification of synthetic polymers after the
    treatment of paper materials): Cellulosa e Carta, 4 (1994),
    pp.45-48 (in Italian).

Paolo Calvini
Paper Conservation Scientist
S.B.A.A.L
10, via Balbi - 16126 Genova
Italy

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                  Conservation DistList Instance 11:43
                Distributed: Thursday, November 6, 1997
                       Message Id: cdl-11-43-006
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