Degradation of Cellulose-based polymers in complex environments

Cellulose-based polymers such as cellulose acetate are of increasing interest as bio-based materials. However, their environmental degradability is a complex question. Approximately 4.5 trillion cellulose acetate cigarette filters are discarded annually and these are often persistent as litter.1 In contrast, cellulose-based polymers in many museum collections have been observed to decay rapidly, leading to loss of valuable cultural heritage.2 Specific degradation mechanisms such as hydrolytic deacetylation and photolytic chain scission are known. However, an understanding of the way these degradation mechanisms interact in complex environments is needed to better understand how these materials degrade, both in the natural environment and in museums.3 This collaborative project between the UCL Institute for Sustainable Heritage and the UCL Institute for Sustainable Resources aims to understand these interactions. Relationships between photo-oxidative and hydrolytic processes will be explored, in addition to accompanying changes in physical properties. The student will conduct accelerated aging experiments and use analytical techniques such as Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared (FTIR) spectroscopies, Gel Permeation Chromatography (GPC) and tensile testing to understand changes in material properties. This project is expected to have a significant impact on both the issue of persistent plastic litter and on heritage conservation.