|
| |  Knowledge
about the dominant cellulose scission reaction is of central importance to the
design of preservation strategies of paper.
The main question is whether strength loss in cellulose fibers is
predominantly due to acid-catalyzed hydrolysis, direct oxidative
cleavage, or substantial contributions from both.
The combination of functional group (formation of carbonyl and carboxyl
groups) and molecular weight (degree of polymerization) analysis offers promise
in characterizing the dominant scission chemistry of pure cellulose paper in a
variety of environments.
The research focus is on:
- Evaluating
the analytical method on acid-catalyzed hydrolysis of cellulose, a well
understood degradation chemistry.
- Determining
the effect on cellulose degradation when exposing paper to chemical
oxidants, near-ultraviolet light, and different thermal aging conditions.
- Monitoring
initially oxidized degraded paper, which is further exposed to oven aging.
The results obtained for acid-treated cellulose fibers
corresponded well with previous studies on acid-treated cotton and validated our
current methodology of monitoring functional group and molecular weight changes.1
Carbonyl production in excess of new chain ends is found when paper is
exposed to oxidizers such as acidic hypochlorite, hydrogen peroxide, and near-ultraviolet light.
Samples thermally aged in both humid and dry conditions degrade
almost exclusively by hydrolysis. Paper
exposed to oxidation reactions may be both initially degraded as well as
compromised in its long term stability by the creation of weak links in the
cellulose chain that are more easily broken.2
For more information:
1. Whitmore et al. Restaurator, 15 (1994)
26-45. (Abstract)
(pdf [832 KB])
2. Whitmore et al. Restaurator, 16 (1995)
10-30. (Abstract) (pdf
[816 KB])
3.
Bogaard et al. JAIC, 46 (2005) 63-74. (Abstract) (pdf)
Top of page
|
