The deterioration of cellulose in papers can be affected not only by the intrinsic quality of the material but also by the quality of the storage environment in which the materials are held.  We have monitored the effect of storing unbuffered acid-free paper in close proximity to poorer quality papers containing acid and lignin as well as the effect of fluctuating humidity environments on paper stability. 

Current research focuses on:

• Understanding the effect of filter paper aged in proximity to low quality paper and paperboards.

• Determining if humidity fluctuations (cycling between 25 and 75% relative humidity every two hours) pose a risk of inducing discoloration and strength loss in paper, and the mechanism for that damage.

During storage of acid-free paper in an acid-containing environment, lignin free housing caused nearby filter paper to hydrolyze more rapidly, probably from transfer of acidic emissions from the aging enclosure.  Housing in enclosures that contained lignin also accelerated the degradation of nearby filter paper, but in this instance there was evidence of both oxidative damage and hydrolysis.  The humidity studies have shown that significant cellulose deterioration occurs in fluctuating humidity conditions, but no evidence of cellulose oxidation has been found.

Paper exposed to room temperature and cycling humidity conditions experienced a large drop in the degree of polymerization and a severe loss of paper strength. Through the use of chemical analysis the degradation mechanism is determined to be by hydrolysis possibly induced by the physical stresses on the cellulose chains as they respond to moisture changes. 

For more information:
            Bogaard  et al. International Institute for Conservation, Baltimore (2002): 11-15. (Abstract) (pdf [512 KB])

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