Lecture on accelerated aging of cellulosic materials

Accelerated Aging of Cellulosic Materials and its Relevance to
Natural Aging
Dr. David Erhardt of the Smithsonian Center for Materials Research
and Education
National Gallery of Art
West Building Lecture Hall
March 16, 1999
10:30 AM

Abstract: It is critical to understand the aging processes of
materials in museums and archives in order to determine appropriate
storage and display environments, and to evaluate the effects of
treatments. Many aging processes that take place in the museum are
too slow to study directly, and this is especially true for a
material as inherently stable as cellulose. Other approaches must be
used. One can study naturally aged materials, but the information
gained is limited because the original properties of the materials
and the aging environment (the conditions of the experiment) usually
are not known or controllable. An alternative is the accelerated
aging of new materials.

Accelerated aging conditions may include elevated temperatures or
relative humidities, or exposure to intense light or high
concentrations of pollutants. Though it is easy to induce changes in
cellulose with extreme conditions, it is difficult to verify that
the resulting changes directly correlate with those of  natural
aging and are thus relevant to objects in the museum.

This talk will begin with a discussion of the requirements for the
equivalence of aging conditions, and approaches to determine whether
these requirements are met for the accelerated aging of cellulose.
Results of physical and chemical testing of paper samples aged under
various conditions will be discussed. The extent to which the
results are consistent with, and can be used to predict, results
obtained for similar tests of naturally aged samples will be
examined.

All are welcome to attend.

Deborah A. Barclift
Conservation Division
National Gallery of Art
202-842-6761
Fax: 202-842-6886

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                  Conservation DistList Instance 12:71
                 Distributed: Wednesday, March 3, 1999
                       Message Id: cdl-12-71-008
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