Peter Leerkamp: Deacidification and strengthening of acidified books and documents: Polymer strengthening of acidified paper

Cellulosic materials like paper and textile are prone to disintegration due to acid catalysed hydrolysis, bacterial processes, light and/or oxidation. These processes are a threat, especially to our paper based cultural heritage. At this moment many books and documents, especially from the 19TH and 20TH century, are in poor condition due to the on-going acidification process.

At the moment there are no processes available that both stop the deterioration process and simultaneously strengthen the fibre structure. Omniaccess BV in the Netherlands has developed the Papercare process for mass deacidification of books with simultaneous reinforcement of the fibre structure. This novel process is based on the deposition of reactive additives with alkaline groups that form a polymer structure in the paper.

The polymer causes an increase in tensile strength of 20% or more. pH after treatment is in the range 7- 9.

Currently we are trying to deacidify complete books without opening them. The results of these experiments will be presented.