An autocatalytic model for the degradation in sealed vessels has been developed in order to investigate the key factors that influence the degradation of paper in an enclosed environment or arranged in stacks. Owing to the non-linearity of the model an analytical solution cannot be easily found, but a computer simulation shows in a qualitative way that the initial acidity of paper plays a role on the shape of the kinetic plots, while an increase in the rate of development of volatile acidic compounds (VOCs) causes an increase in the rate of degradation. Our results indicate that the initial acidity and the chemical mechanism of oxidation, other than the degree of polymerisation, should be taken into account in the studies of both accelerated and natural ageing of paper in non-ventilated environments
