Plastic has transformed society. From the invention of early materials such as celluloid or cellulose acetate in the late 19th and early 20th centuries, to our contemporary mass production and consumption of plastics, plastic has influenced the way we dress, consume food, make art, conduct warfare and communicate with one another. In addition to its impact on society, plastic waste has had a catastrophic effect on our natural environment, with millions of tonnes entering our oceans every year.
Such a consequential part of modern history and our impact on the planet needs to be documented and understood. Collecting and caring for plastic artefacts in helps to ensure that the complicated legacy of plastics can be understood and evaluated both now and by future generations. Unfortunately, the conservation of plastics in museums presents a difficult challenge. Many plastics are very unstable under museum conditions. Plastic artefacts in museums have been found to deteriorate dramatically over much shorter periods than more traditional materials such as stone or glass.
The challenges of conserving plastics in museums have been understood for approximately 30 years and key degradation mechanisms have been identified. However, translating this into an understanding of how plastic objects actually behave is challenging, as different degradation mechanisms have complex relationships both with each other and with the environmental conditions surrounding a plastic object such as the temperature or relative humidity. This was expressed shortly before COMPLEX by researchers at the Getty Conservation Institute in Los Angeles:
“our understanding of plastics stability remains rudimentary. We have a menu of mechanisms that potentially explain degradation, but there is a tendency to default to them and recite them, rather than investigate sceptically what is actually going on.”
Tom Learner and Odile Madden (2014)
The COMPLEX project aimed to address this gap. Inspired by the field of system dynamics, COMPLEX mathematically modelled the degradation of plastic museum objects as complex systems. With a focus on the polymer cellulose acetate, COMPLEX developed a mathematical model that captured the key chemical and physical degradation processes of a plastic artefact and the relationships between these processes and the surrounding environment. This allowed us to identify processes or compositional factors which have the most significant impact on the degradation of plastic museum artefacts, supporting improved conservation decision-making. In addition, COMPLEX introduced a novel way of approaching the study of polymer degradation, as this systems-based approach can be applied to other problems such as plastic waste in the environment.
The key objectives of COMPLEX can be summarised as follows:
- to introduce to the fields of both plastics conservation and polymer degradation a new way of understanding and modelling the degradation of plastic objects: using a system dynamics approach.
- to provide evidence-based guidance on the storage and display of plastic objects in museum collections
The project was done in collaboration with expert partners Tate, the Museum of London, Lacerta Technologies and Process Systems Enterprise.