%0 Thesis
%9 Doctoral
%A King, Rose
%B Institute of Sustainable Heritage
%D 2024
%F discovery:10195453
%I UCL (University College London)
%P 431
%T Plasticisers in Historic Plastics: Spectroscopic and Chromatographic Approaches for Cellulose Acetate and Polyvinyl Chloride
%U https://discovery.ucl.ac.uk/id/eprint/10195453/
%X The presence of plastic objects in museum collections reflects their use as a material  for artistic expression, and their widespread use in our everyday lives. Their  conservation is tailored to the plastic type or polymer, but the role of additives within  a plastic formulation can be overlooked. Plasticiser additives are used to  manufacture CA and PVC and are designed to remain within the plastic to impart  flexibility. Instead, they can migrate out of the plastic due to the surrounding  environment or the plasticiser’s chemical characteristics. As such the additive can  influence the migration rate and consequently aging behaviour of a plasticised  object, but few studies have linked an objects degradation behaviour with the  additives present.  Non-destructive methods were developed for PVC identification using new ATR  libraries and ER-FTIR spectroscopy. ER-FTIR spectra were also used to identify  aromatic plasticisers without requiring destructive GC-MS or NMR methods.  Additionally, a minimally invasive sampling method using surface swabs were shown  to allow sampling of degradation products, before a simple, cost-effective thin layer  chromatography method can be used to widen the range of observable analytes  versus the ER-FTIR spectroscopy method.  For CA, a preliminary attempt at magnetic resonance imaging suggested water and  plasticiser content could be studied across three-dimensional CA samples.  Additionally, a new data processing method for 1H NMR data allows for the  measurement of additive and acetic acid concentrations, as well as the degree of  substitution within a single sample. It is hoped the method can be developed further and used to identify links between chemical composition and degradation behaviour  for objects.  Overall, the proposed techniques aim to enable conservation practitioners to assess  the condition and composition of plastic objects in museum collections. By employing  these methods, conservators can gain insights into the effect of a plastic object’s  additive formulation on its aging behaviour.
%Z Copyright © The Author 2024.  Original content in this thesis is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) Licence (https://creativecommons.org/licenses/by-nc/4.0/).  Any third-party copyright material present remains the property of its respective owner(s) and is licensed under its existing terms.  Access may initially be restricted at the author’s request.