Title
Effects of different consolidation additives on ageing behaviour of archived document paper
Authors
E. Ardelean E. Bobu Gh. Niculescu and C. Groza

Received April 21, 2010
Published Volume 45 Issue 1-2 January-February
Keywords chitosan, carboxymethyl chitosan, cellulose ethers, paper restoration, paper ageing

Abstract
Consolidation additives are used in the restoration of old paper documents for partial recovery of the loss of structural strength by natural ageing, as well as for reducing their further deterioration, due to environmetal action. The study evaluates the effectiveness of some unconventional chitosan-based additives, comparatively with conventional consolidation additives based on cellulose ethers. The effectiveness of consolidation additives was investigated by their direct effects on the paper properties, as well as by accelerated thermal ageing behaviour of the consolidated paper samples. The results pointed out that chitosan acetate (CHa) and carboxymethylchitosan (CMCH) lead to a significant improvement of the paper strength properties (especially burst strength) and to the reduction of water absorption capacity, which results in a better preservation of the consolidation effect over time. The investigation of paper surface topography by the AFM technique evidenced better film forming properties and higher efficiency of the chitosan derivatives over time, compared to conventional treatments based on cellulose ethers.