Hostname: page-component-78c5997874-ndw9j Total loading time: 0 Render date: 2024-11-07T20:08:59.520Z Has data issue: false hasContentIssue false
  • English
  • Français

Accelerated VS Natural Aging: Effect of Aging Conditions on the Aging Process of Cellulose

Published online by Cambridge University Press:  26 February 2011

David Erhardt  and
Marion F. Mecklenburg
David Erhardt
Affiliation:
Conservation Analytical Laboratory, Smithsonian Institution, Washington, DC 20560, USA
Marion F. Mecklenburg
Affiliation:
Conservation Analytical Laboratory, Smithsonian Institution, Washington, DC 20560, USA
Get access

Abstract

This paper discusses the kinetics of aging and its implications for the evaluation of changes in the aging process, especially as applied to accelerated aging. The problem of comparing accelerated aging conditions is shown to be separate from that of evaluating changes occurring under one specific set of conditions. Thus tests and measurements that can be used to evaluate the results of a specific accelerated aging experiment are not necessarily valid for use in determining whether two sets of aging conditions are comparable. This distinction is crucial in trying to determine whether a set of aging conditions is comparable to, or accurately simulates, natural aging. The criteria for comparing two sets of aging conditions are defined, and applied to the problem of evaluating accelerated aging conditions. Data from the analysis of individual reaction products of artificially aged paper samples are used to determine the effects of temperature and relative humidity (RH) on the rates of individual reactions. Changes in the distribution of reaction products are used as indicators of changes in the aging process. The aging process of cellulose under the conditions studied (60–90°C, 30–80% RH) is shown to be RH dependent, but relatively temperature independent. Thus raising the temperature at constant RH speeds up the aging process without significantly altering it. If the RH is changed, then the aging process is altered and equivalent states of aging cannot be reached. Accelerated aging should be conducted at the same relative humidity as the conditions to which the results are to be applied. The data also indicate that lowering the relative humidity from 50% to 30% slows the rate of hydrolysis by a factor of three to five times.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 352: Symposium – Materials Issues in Art and Archaeology IV , 1995 , 247
Copyright
Copyright © Materials Research Society 1995

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Lindström, T., in TAPPI Proceedings: 1988 Paper Preservation Symposium (TAPPI Press, Atlanta, 1988), pp. 69–71.Google Scholar
2. TAPPI Method T 544, “Effect of moist heat on properties of paper and board”, specifies aging at 90°C and 25% relative humidity. TAPPI Method T 453, “Effect of dry heat on properties of paper”, specifies dry aging at 105°C. With normal room air, this results in a relative humidity of about 1%. The latest update of this method includes several statements to the effect that moist aging probably provides better correlation with natural aging. TAPPI Method T 260, “Test to evaluate the aging properties of bleached chemical pulps”, specifies aging at 100% relative humidity at 100°C in order to test for brightness reversion. Interestingly, these conditions would result in an atmosphere of pure water vapor. Thus, these three conditions effectively provide oxygen and water, oxygen and no water, and water and no oxygen, respectively.Google Scholar
3. Frost, A.A. and Pearson, R.G., Kinetics and Mechanism, 2nd ed. (John Wiley & Sons, Inc., New York, 1961), pp. 8–26.Google Scholar
4. ibid., p. 22.Google Scholar
5. Erhardt, D., Abbey Newsletter 13 (3), 38–39 (1989).Google Scholar
6. Roberson, in a search of the literature, found activation energies in the general range of 26 to 29 kcal/mol for the hydrolysis of cellulose, and an activation energy of 20-30 kcal/mole for the crosslinking of cellulose (Roberson, D.D., Tappi 59, 63 (1976)). Springer reported an activation energy of 28.2 kcal/mol for the removal of xylan (a polymer of the wood sugar xylose) from wood by acid hydrolysis (E.L. Springer, Tappi 49, 102 (1966)).Google Scholar
7. Block, Ira, in ICOM Committee for Conservation, 7th Triennial Meeting, Copenhagen, 10-14 September 1984, Preprints, Vol. 1, edited by Froment, D. de, (ICOM Committee for Conservation, Paris, 1984) pp. 84.9.7–84.9.10.Google Scholar
8. Vitale, Tim and Erhardt, David, in ICOM Committee for Conservation, lOth Triennial Meeting, Washington, DC, USA, 22-27 August 1993, Preprints, Volume II, edited by Bridgland, J. (ICOM Committee for Conservation, Paris, 1993), pp. 507–515.Google Scholar
9. Erhardt, David, Endt, David von, and Hopwood, Walter, in The American Institute for Conservation of Historic and Artistic Works Preprints of Papers Presented at the Fifteenth Annual Meeting, Vancouver, British Columbia, Canada, May 20-24, 1987, edited by Brown, A.G. (The American Institute for Conservation of Historic and Artistic Works, Washington, 1987), pp. 43–55.Google Scholar
10. Mecklenburg, Marion F. and Tumosa, Charles S., in Art in Transit: Studies in the Transport of Paintings, edited by Mecklenburg, M.F. (National Gallery of Art, Washington, 1991) pp. 173–216.Google Scholar
11. Michalski, Stefan, in ICOM Committee for Conservation, lOth Triennial Meeting, Washington, DC, USA, 22-27 August 1993, Preprints, Volume II, edited by Bridgland, J. (ICOM Committee for Conservation, Paris, 1993), pp. 624–629.Google Scholar
12. Graminski, E.L., Parks, E.J., and Toth, E.E., The Effects of Temperature and Moisture on the Accelerated Aging of Paper (Washington: US Dept. of Commerce, NTIS, Report #PB-279 046, by NBS Polymer Division, February 1978).Google Scholar
13. Erhardt, D. and Mecklenburg, M., in a paper to be published in the proceedings of the 15th International Congress of the International Institute for Conservation to be held September 12-16, 1994.Google Scholar