Lignin is a natural product that represents a large part of the Earth’s biosphere and is an important source of energy, as well as a constituent of many industrial products. Among others, it is present in environmentally friendly packaging coatings and in paper produced from wood pulp.
In this project, we will explore the effect of lignin degradation on cellulose-based materials listed above in two “extreme” contexts: during long-term environmental degradation and during composting. The results will enable an understanding of the impact of lignin on long-term degradation of lignin-rich paper in heritage collections and a better design of parameters affecting biodegradability of lignin-rich materials.
Impacts & Results
The projects goals are:
To assess the validity of existing paper damage functions for lignin-containing paper
To develop analytical methods to follow the accumulation of lignin-based material degradation products in composting media and in storage environments
To obtain understanding of the impact of lignin degradation on the degradation of cellulose under composting conditions and in alum-sized archival paper in storage
The HSLL collection of sacrificial historic paper will be investigated with spectroscopic (Raman) and chromatographic (LC-MS, IC, SEC, GC-MS) methods to analyse lignin, resin acid and cellulose degradation products after accelerated degradation at raised temperature and humidity.
The rate of paper degradation will be followed as MW loss of cellulose and modelled using multivariate data analysis techniques. The damage function for lignin-free paper will be evaluated and corrected if necessary to include paper containing lignin.
Four types of lignin from plants will be isolated, characterised, and used for coating formulations. The coating properties will then be evaluated.
Biodegradability and disintegration will be tested for the prepared materials, the processes monitored by spectroscopical and LC-MS methods. The relationship between lignin content in the coating and the rate of degradation of the material as a whole will be explored.