The kinetics of cellulose degradation was analysed by means of a two-stage model, characterised by an autoretardant and autocatalytic regime, later tempered by the consumption of glycosidic bonds in the amorphous regions. The proposed model explains the effects on the kinetic equations of different modes of ageing (acid hydrolysis, ageing in ventilated oven or sealed vessels), initial oxidation of cellulose and experimental procedures (with or without reduction of oxidised groups). The autoretardant branch can be analysed in a quantitative way, while the integration of the non-linear autocatalytic branch is allowed in some cases, characterised by the decrease of pH and/or emission of acid volatile organic compounds (VOCs). Most of the controversial results of the literature can be easily explained, but the proposed model offers also a guide for further studies on the kinetics of cellulose degradation.

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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

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