Accelerated ageing of paper: effect of lignin content and humidity on tensile properties

Abstract

Paper degradation menaces the useful lifetime of books, manuscripts, and works on paper during storage, circulation, and display in libraries, archives, and museums. Severe damages such as embrittlement, decay, and mold often occur to the paper that might threaten to lose cultural heritage. However, the shelf life of papers stored in suitable conditions can be extended by hundreds of years. The most important external factors affecting the deterioration of paper-based materials include, in particular, changes in temperature and air humidity. In this study, the effects of accelerated aging under different conditions, including substantially different relative humidity, were considered relative to the strength properties of the paper sheets. These include the mechanical strength, such as breaking length, tear resistance, and bursting strength of the paper samples before and after dry heat aging and hydrothermal aging. Samples with various content of lignin produced in neutral pH were examined to exclude the adverse influence of acidity on paper properties. The results indicate that impact of moisture on tensile properties and pH-value of paper is much greater than the effect of increased temperature. The results of this work are intended to consolidate and expand the theoretical foundation and provide technical support for the conservators and library staff on the storage of paper cultural relics.

Chitosan-Coated Packaging Papers—Strength and Thermal Stability

“…Three major ambitions of carrying out the accelerated paper aging are stated hereafter: firstly, to provide the relative ranking of materials or physical combination of materials in a conveniently short time, with respect to their physical durability or chemical stability; secondly, to predict or to evaluate the potential long-term appropriateness of material systems under proposed conditions of use; thirdly, to elucidate the chemical reactions involved (the degradation mechanism) and the physical consequences thereof. Hydrolytic degradation has been discussed as the most important cause for the decrease in paper strength properties and the lignin content as the most important aging factor [39,40]. In the current experiment, the fiber cellulose material was bleached (lignin content is lower than 9%), so it cannot be a curtailing factor for paper color changes during accelerated thermal aging.…”

Potential effects of nano-cellulose and nano-silica/polyvinyl alcohol nanocomposites in the strengthening of dyed paper manuscripts with madder: an experimental study

“…The natural lignin in the paper composition, accelerates the rate of cellulose disintegration, especially in sunlight or industrial light, causing the paper to yellow, fade or darken due to the absorption of harmful UV rays 19 , 20 . Moreover, it also causes dehydration and brittleness 21 .…”

Differentiating between Natural and Modified Cellulosic Fibres Using ATR-FTIR Spectroscopy

“…The most serious conservation problem for cellulosic materials is the photochemical damage [10,15]; however, oxidation can occur in a dark and humid environment, especially when there are temperature fluctuations [10,16,17]. After absorbing electromagnetic radiation, free radical photochemical reactions start in the cellulose.…”

“…Lignin probably also acts as a radical scavenger [17][18][19][20], despite it being considered to cause damage. The literature [15,17] also stresses that controlling humidity levels is essential in the conservation of paper and of both modified and natural cellulosic textiles.…”

“…Lignin probably also acts as a radical scavenger [17][18][19][20], despite it being considered to cause damage. The literature [15,17] also stresses that controlling humidity levels is essential in the conservation of paper and of both modified and natural cellulosic textiles. Too high levels can lead to a microbiological attack as well as migration of dyes and pigments, while shrinkage and brittleness are caused by too low levels.…”