The sculpture Goodyear Field (1996) by contemporary artist Matthew Barney was created in relation to the film Cremaster 1 (1995), which belongs to the art project Cremaster Cycle, consisting of five feature-length films including sculptures, photographs and drawings. Today, the artwork is shown in one of the storage/viewing rooms at Schaulager in Münchenstein near Basel.
Goodyear Field consists of a broad variety of different synthetic materials, as identified through μFTIR analysis. One particular plastic present in the sculpture has not received much attention in conservation science and practice so far: Polycaprolactone (PCL). Barney has used PCL extensively as an artistic medium throughout his oeuvre. He defined the material as “prosthetic plastic” in the context of Goodyear Field and used it in the form of sheets known under the brand name Aquaplast®, which is a cross-linked form of PCL. Aside from Matthew Barney, other contemporary artists and designers also work with this material, mainly in the form of linear PCL pellets, which are known as “Friendly Plastic®”, “Polymorph” or “ShapeLock”.
PCL is a thermoplastic, aliphatic polyester originally used for biomedical applications and the manufacturing of orthopedic casts. The polymer’s multi-faceted uses, including its low melting point, makes it attractive as an artistic medium, as the artist can easily heat up the material with warm air or water and shape it by hand. It is foreseeable that future contemporary artists and designers will continue working with this unique material, as a result conservators most likely will be faced with the preservation of artworks containing PCL.
The main goal of the MA thesis written at the University of Applied Sciences Bern was to gain fundamental knowledge on the technology, material characteristics and aging behavior of this unique polymer. In addition to a literature study and test series, an interview with Matthew Barney provided precious information about PCL as well as the artist’s motives to work with this specific material.
Due to preliminary signs of aging, such as yellowing, observed on the PCL sheets in Goodyear Field, as well as the little research literature published on the photo-oxidative aging behavior of PCL, the thesis examines PCL’s aging stability with a special focus on the photo-oxidative aging behavior of the polymer when stored in museums and collections. Light-aging tests were performed by exposing both linear and cross-linked PCL samples to different kinds of light sources. In order to investigate the impact of the different processing techniques used by artists on the light aging-resistance of PCL, additional samples were created according to his working methods. Results gained by colorimetry showed that the filtering of UV-components of the light sources used in museum environment could prevent light-induced damages, such as yellowing.