@phdthesis{discovery10195453,
          school = {UCL (University College London)},
            note = {Copyright {\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.},
           month = {August},
            year = {2024},
           title = {Plasticisers in Historic Plastics: Spectroscopic and Chromatographic Approaches for Cellulose Acetate and Polyvinyl Chloride},
             url = {https://discovery.ucl.ac.uk/id/eprint/10195453/},
        abstract = {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.},
          author = {King, Rose}
}