On the Rate of Paper Degradation: Lessons From the Past

The kinetics of paper degradation has been reviewed briefly and updated in order to emphasise the key factors that have been (and still are) largely neglected in the interpretation of experimental results. A simple re-elaboration of the literature data reveals many questionable statements in the field of paper conservation science. In particular, it is shown that accelerated ageing techniques do not allow any prediction of the life expectancy of paper, owing to the exponential structure of the Arrhenius relationship. Moreover, some results obtained from viscometric analyses appear misinterpreted, since the experimental planning does not differentiate the actual (hydrolytic) from the potential (oxidative) degradation of cellulose. Finally, the widely utilised pseudo zero-order kinetics of degradation leads to questionable statements, since most of the mechanisms of paper degradation do not follow such a simple pathway, so that the results of the research in the field of paper conservation science should be in part revised.